[svn-r1034] Changed spelling of extendable to extendible just for consistency sake.

author: Albert Cheng <acheng@hdfgroup.org> 1999-01-27 04:08:32 (GMT)
committer: Albert Cheng <acheng@hdfgroup.org> 1999-01-27 04:08:32 (GMT)
commit: 2df1f8344e833c8c64a66615bf0a4f18a5da1f96 (patch)
tree: e6ffd39560c311a20b9e4155f6e01fbe2da283ba /testpar
parent: f7cd022ac47731c1781dfc408a729e00bf15d338 (diff)
download: hdf5-2df1f8344e833c8c64a66615bf0a4f18a5da1f96.zip
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1 files changed, 8 insertions, 8 deletions
diff --git a/testpar/t_dset.c b/testpar/t_dset.c
index e40d84b..b818103 100644
--- a/testpar/t_dset.c
+++ b/testpar/t_dset.c
@@ -9,8 +9,8 @@
  *
  * This program contains two major parts.  Part 1 tests fixed dimension
  * datasets, for both independent and collective transfer modes.
- * Part 2 tests extendable datasets, for independent transfer mode
- * only.  Collective mode for extendable datasets are not supported yet.
+ * Part 2 tests extendible datasets, for independent transfer mode
+ * only.  Collective mode for extendible datasets are not supported yet.
  */
 
 #include <testphdf5.h>
@@ -760,11 +760,11 @@ dataset_readAll(char *filename)
 
 
 /*
- * Part 2--Independent read/write for extendable datasets.
+ * Part 2--Independent read/write for extendible datasets.
  */
 
 /*
- * Example of using the parallel HDF5 library to create two extendable
+ * Example of using the parallel HDF5 library to create two extendible
  * datasets in one HDF5 file with independent parallel MPIO access support.
  * The Datasets are of sizes (number-of-mpi-processes x DIM1) x DIM2.
  * Each process controls only a slab of size DIM1 x DIM2 within each
@@ -844,11 +844,11 @@ extend_writeInd(char *filename)
     sid = H5Screate_simple (RANK, dims, max_dims);
     VRFY((sid != FAIL), "H5Screate_simple succeeded");
 
-    /* create an extendable dataset collectively */
+    /* create an extendible dataset collectively */
     dataset1 = H5Dcreate(fid, DATASETNAME1, H5T_NATIVE_INT, sid, dataset_pl);
     VRFY((dataset1 != FAIL), "H5Dcreate succeeded");
 
-    /* create another extendable dataset collectively */
+    /* create another extendible dataset collectively */
     dataset2 = H5Dcreate(fid, DATASETNAME2, H5T_NATIVE_INT, sid, dataset_pl);
     VRFY((dataset2 != FAIL), "H5Dcreate succeeded");
 
@@ -915,7 +915,7 @@ extend_writeInd(char *filename)
     mem_dataspace = H5Screate_simple (RANK, count, NULL);
     VRFY((mem_dataspace != FAIL), "");
 
-#ifdef DISABLE
+#ifndef DISABLE
     /* Try write to dataset2 beyond its current dim sizes.  Should fail. */
     /* Temporary turn off auto error reporting */
     H5Eget_auto(&old_func, &old_client_data);
@@ -974,7 +974,7 @@ extend_writeInd(char *filename)
     H5Fclose(fid);							    
 }
 
-/* Example of using the parallel HDF5 library to read an extendable dataset */
+/* Example of using the parallel HDF5 library to read an extendible dataset */
 void
 extend_readInd(char *filename)
 {
diff --git a/.gitignore b/.gitignore
index 3fe3259..7c12ce3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,11 +9,8 @@
 *~
 .gdb_history
 Doc/build/
-Doc/tools/docutils/
-Doc/tools/jinja/
-Doc/tools/jinja2/
-Doc/tools/pygments/
-Doc/tools/sphinx/
+Doc/venv/
+Lib/distutils/command/*.pdb
 Lib/lib2to3/*.pickle
 Lib/test/data/*
 Lib/_sysconfigdata.py
@@ -27,18 +24,30 @@ Modules/Setup.config
 Modules/Setup.local
 Modules/config.c
 Modules/ld_so_aix
-Modules/_freeze_importlib
-Modules/_testembed
-PCbuild/*.bsc
-PCbuild/*.dll
-PCbuild/*.exe
-PCbuild/*.exp
-PCbuild/*.lib
-PCbuild/*.ncb
-PCbuild/*.o
-PCbuild/*.pdb
-PCbuild/Win32-temp-*
+Programs/_freeze_importlib
+Programs/_testembed
+PC/python_nt*.h
+PC/pythonnt_rc*.h
+PC/*/*.exe
+PC/*/*.exp
+PC/*/*.lib
+PC/*/*.bsc
+PC/*/*.dll
+PC/*/*.pdb
+PC/*/*.user
+PC/*/*.ncb
+PC/*/*.suo
+PC/*/Win32-temp-*
+PC/*/x64-temp-*
+PC/*/amd64
+PCbuild/*.user
+PCbuild/*.suo
+PCbuild/*.*sdf
+PCbuild/*-pgi
+PCbuild/*-pgo
 PCbuild/amd64/
+PCbuild/obj
+PCBuild/win32
 .purify
 Parser/pgen
 __pycache__
@@ -61,6 +70,7 @@ pyconfig.h
 python$
 python-config
 python-config.py
+python.bat
 python.exe
 python-gdb.py
 python.exe-gdb.py
@@ -72,3 +82,6 @@ TAGS
 coverage/
 externals/
 htmlcov/
+Tools/msi/obj
+Tools/ssl/amd64
+Tools/ssl/win32
diff --git a/.hgignore b/.hgignore
index 9e5a583..7a52606 100644
--- a/.hgignore
+++ b/.hgignore
@@ -9,6 +9,7 @@ TAGS$
 autom4te.cache$
 ^build/
 ^Doc/build/
+^Doc/venv/
 buildno$
 config.cache
 config.log
@@ -18,6 +19,7 @@ db_home
 platform$
 pyconfig.h$
 python$
+python.bat$
 python.exe$
 python-config$
 python-config.py$
@@ -48,13 +50,12 @@ libpython*.so*
 *.pyd
 *.cover
 *~
+Lib/distutils/command/*.pdb
 Lib/lib2to3/*.pickle
 Lib/test/data/*
 Misc/*.wpu
 PC/python_nt*.h
 PC/pythonnt_rc*.h
-PC/*.obj
-PC/*.exe
 PC/*/*.exe
 PC/*/*.exp
 PC/*/*.lib
@@ -67,29 +68,20 @@ PC/*/*.suo
 PC/*/Win32-temp-*
 PC/*/x64-temp-*
 PC/*/amd64
-PCbuild/*.exe
-PCbuild/*.dll
-PCbuild/*.pdb
-PCbuild/*.lib
-PCbuild/*.exp
-PCbuild/*.o
-PCbuild/*.ncb
-PCbuild/*.bsc
 PCbuild/*.user
 PCbuild/*.suo
 PCbuild/*.*sdf
-PCbuild/Win32-temp-*
-PCbuild/x64-temp-*
 PCbuild/*-pgi
 PCbuild/*-pgo
 PCbuild/amd64
-PCbuild/ipch
+PCbuild/obj
+PCbuild/win32
 Tools/unicode/build/
 Tools/unicode/MAPPINGS/
 BuildLog.htm
 __pycache__
-Modules/_freeze_importlib
-Modules/_testembed
+Programs/_freeze_importlib
+Programs/_testembed
 .coverage
 coverage/
 externals/
@@ -98,3 +90,6 @@ htmlcov/
 *.gcno
 *.gcov
 coverage.info
+Tools/msi/obj
+Tools/ssl/amd64
+Tools/ssl/win32
diff --git a/.hgtags b/.hgtags
index d5eea24..21a2a38 100644
--- a/.hgtags
+++ b/.hgtags
@@ -144,3 +144,7 @@ c0e311e010fcb5bae8d87ca22051cd0845ea0ca0 v3.4.1
 ab2c023a9432f16652e89c404bbc84aa91bf55af v3.4.2
 69dd528ca6255a66c37cc5cf680e8357d108b036 v3.4.3rc1
 b4cbecbc0781e89a309d03b60a1f75f8499250e6 v3.4.3
+5d4b6a57d5fd7564bf73f3db0e46fe5eeb00bcd8 v3.5.0a1
+0337bd7ebcb6559d69679bc7025059ad1ce4f432 v3.5.0a2
+82656e28b5e5c4ae48d8dd8b5f0d7968908a82b6 v3.5.0a3
+413e0e0004f4f954331cb8122aa55fe208984955 v3.5.0a4
diff --git a/.hgtouch b/.hgtouch
index 7e3a5e7..b9be0f1 100644
--- a/.hgtouch
+++ b/.hgtouch
@@ -2,7 +2,9 @@
 # Define dependencies of generated files that are checked into hg.
 # The syntax of this file uses make rule dependencies, without actions
 
-Python/importlib.h: Lib/importlib/_bootstrap.py Modules/_freeze_importlib.c
+Python/importlib.h: Lib/importlib/_bootstrap.py Programs/_freeze_importlib.c
+
+Include/opcode.h:  Lib/opcode.py Tools/scripts/generate_opcode_h.py
 
 Include/Python-ast.h: Parser/Python.asdl Parser/asdl.py Parser/asdl_c.py
 Python/Python-ast.c: Include/Python-ast.h
diff --git a/Doc/Makefile b/Doc/Makefile
index ea30231..200a9f7 100644
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -15,11 +15,12 @@ ALLSPHINXOPTS = -b $(BUILDER) -d build/doctrees -D latex_paper_size=$(PAPER) \
 
 .PHONY: help build html htmlhelp latex text changes linkcheck \
 	suspicious coverage doctest pydoc-topics htmlview clean dist check serve \
-	autobuild-dev autobuild-stable
+	autobuild-dev autobuild-stable venv
 
 help:
 	@echo "Please use \`make <target>' where <target> is one of"
 	@echo "  clean      to remove build files"
+	@echo "  venv       to create a venv with necessary tools"
 	@echo "  html       to make standalone HTML files"
 	@echo "  htmlview   to open the index page built by the html target in your browser"
 	@echo "  htmlhelp   to make HTML files and a HTML help project"
@@ -102,7 +103,11 @@ htmlview: html
 	 $(PYTHON) -c "import webbrowser; webbrowser.open('build/html/index.html')"
 
 clean:
-	-rm -rf build/*
+	-rm -rf build/* venv/*
+
+venv:
+	$(PYTHON) -m venv venv
+	./venv/bin/python3 -m pip install -U Sphinx
 
 dist:
 	rm -rf dist
@@ -172,4 +177,3 @@ autobuild-stable:
 		exit 1;; \
 	esac
 	@make autobuild-dev
-
diff --git a/Doc/README.txt b/Doc/README.txt
index 58bda62..580d102 100644
--- a/Doc/README.txt
+++ b/Doc/README.txt
@@ -3,7 +3,7 @@ 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 <https://docs.python.org/3.4/download.html>.
+available at <https://docs.python.org/dev/download.html>.
 
 Documentation on authoring Python documentation, including information about
 both style and markup, is available in the "Documenting Python" chapter of the
diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst
index 3c0f4b9..ed62dea 100644
--- a/Doc/c-api/arg.rst
+++ b/Doc/c-api/arg.rst
@@ -152,7 +152,7 @@ Unless otherwise stated, buffers are not NUL-terminated.
    any conversion.  Raises :exc:`TypeError` if the object is not a Unicode
    object.  The C variable may also be declared as :c:type:`PyObject\*`.
 
-``w*`` (:class:`bytearray` or read-write byte-oriented buffer) [Py_buffer]
+``w*`` (read-write :term:`bytes-like object`) [Py_buffer]
    This format accepts any object which implements the read-write buffer
    interface. It fills a :c:type:`Py_buffer` structure provided by the caller.
    The buffer may contain embedded null bytes. The caller have to call
diff --git a/Doc/c-api/codec.rst b/Doc/c-api/codec.rst
index 83252af..dfe3d43 100644
--- a/Doc/c-api/codec.rst
+++ b/Doc/c-api/codec.rst
@@ -116,3 +116,8 @@ Registry API for Unicode encoding error handlers
    Replace the unicode encode error with backslash escapes (``\x``, ``\u`` and
    ``\U``).
 
+.. c:function:: PyObject* PyCodec_NameReplaceErrors(PyObject *exc)
+
+   Replace the unicode encode error with ``\N{...}`` escapes.
+
+   .. versionadded:: 3.5
diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst
index 66b7752..814317b 100644
--- a/Doc/c-api/exceptions.rst
+++ b/Doc/c-api/exceptions.rst
@@ -9,13 +9,19 @@ 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 :c:data:`errno` variable:
+exception handling.  It works somewhat like the POSIX :c:data:`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 :c:func:`PyArg_\*` functions return ``1`` for success and
-``0`` for failure).
+C API functions don't clear this on success, but will set it to indicate the
+cause of the error on failure.  Most C API 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 :c:func:`PyArg_\*` functions
+return ``1`` for success and ``0`` for failure).
+
+Concretely, the error indicator consists of three object pointers: the
+exception's type, the exception's value, and the traceback object.  Any
+of those pointers can be NULL if non-set (although some combinations are
+forbidden, for example you can't have a non-NULL traceback if the exception
+type is NULL).
 
 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
@@ -27,12 +33,21 @@ 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.
+.. note::
+   The error indicator is **not** the result of :func:`sys.exc_info()`.
+   The former corresponds to an exception that is not yet caught (and is
+   therefore still propagating), while the latter returns an exception after
+   it is caught (and has therefore stopped propagating).
 
-.. XXX Order of these should be more thoughtful.
-   Either alphabetical or some kind of structure.
+
+Printing and clearing
+=====================
+
+
+.. c:function:: void PyErr_Clear()
+
+   Clear the error indicator.  If the error indicator is not set, there is no
+   effect.
 
 
 .. c:function:: void PyErr_PrintEx(int set_sys_last_vars)
@@ -51,127 +66,24 @@ in various ways.  There is a separate error indicator for each thread.
    Alias for ``PyErr_PrintEx(1)``.
 
 
-.. c:function:: 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 :c:func:`PyErr_Set\*`
-   functions or to :c:func:`PyErr_Restore`).  If not set, return *NULL*.  You do not
-   own a reference to the return value, so you do not need to :c:func:`Py_DECREF`
-   it.
-
-   .. note::
-
-      Do not compare the return value to a specific exception; use
-      :c:func:`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 be a subclass of the expected exception.)
-
-
-.. c:function:: 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.
-
-
-.. c:function:: 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.
-
-
-.. c:function:: void PyErr_NormalizeException(PyObject**exc, PyObject**val, PyObject**tb)
-
-   Under certain circumstances, the values returned by :c:func:`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.
-
-   .. note::
-
-      This function *does not* implicitly set the ``__traceback__``
-      attribute on the exception value. If setting the traceback
-      appropriately is desired, the following additional snippet is needed::
-
-         if (tb != NULL) {
-           PyException_SetTraceback(val, tb);
-         }
-
-
-.. c:function:: void PyErr_Clear()
-
-   Clear the error indicator.  If the error indicator is not set, there is no
-   effect.
-
-
-.. c:function:: 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.
-
-
-.. c:function:: 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 :c:func:`PyErr_Fetch` to save the current
-      exception state.
-
-
-.. c:function:: void PyErr_GetExcInfo(PyObject **ptype, PyObject **pvalue, PyObject **ptraceback)
-
-   Retrieve the exception info, as known from ``sys.exc_info()``.  This refers
-   to an exception that was already caught, not to an exception that was
-   freshly raised.  Returns new references for the three objects, any of which
-   may be *NULL*.  Does not modify the exception info state.
-
-   .. note::
-
-      This function is not normally used by code that wants to handle exceptions.
-      Rather, it can be used when code needs to save and restore the exception
-      state temporarily.  Use :c:func:`PyErr_SetExcInfo` to restore or clear the
-      exception state.
-
-   .. versionadded:: 3.3
-
+.. c:function:: void PyErr_WriteUnraisable(PyObject *obj)
 
-.. c:function:: void PyErr_SetExcInfo(PyObject *type, PyObject *value, PyObject *traceback)
+   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.
 
-   Set the exception info, as known from ``sys.exc_info()``.  This refers
-   to an exception that was already caught, not to an exception that was
-   freshly raised.  This function steals the references of the arguments.
-   To clear the exception state, pass *NULL* for all three arguments.
-   For general rules about the three arguments, see :c:func:`PyErr_Restore`.
+   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.
 
-   .. note::
 
-      This function is not normally used by code that wants to handle exceptions.
-      Rather, it can be used when code needs to save and restore the exception
-      state temporarily.  Use :c:func:`PyErr_GetExcInfo` to read the exception
-      state.
+Raising exceptions
+==================
 
-   .. versionadded:: 3.3
+These functions help you set the current thread's error indicator.
+For convenience, some of these functions will always return a
+NULL pointer for use in a ``return`` statement.
 
 
 .. c:function:: void PyErr_SetString(PyObject *type, const char *message)
@@ -197,6 +109,14 @@ in various ways.  There is a separate error indicator for each thread.
    string.
 
 
+.. c:function:: PyObject* PyErr_FormatV(PyObject *exception, const char *format, va_list vargs)
+
+   Same as :c:func:`PyErr_Format`, but taking a :c:type:`va_list` argument rather
+   than a variable number of arguments.
+
+   .. versionadded:: 3.5
+
+
 .. c:function:: void PyErr_SetNone(PyObject *type)
 
    This is a shorthand for ``PyErr_SetObject(type, Py_None)``.
@@ -346,6 +266,22 @@ in various ways.  There is a separate error indicator for each thread.
    use.
 
 
+Issuing warnings
+================
+
+Use these functions to issue warnings from C code.  They mirror similar
+functions exported by the Python :mod:`warnings` module.  They normally
+print 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 they will raise an exception.  It is also possible that
+the functions raise an exception because of a problem with the warning machinery.
+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, :c:func:`Py_DECREF` owned references and return
+an error value).
+
 .. c:function:: int PyErr_WarnEx(PyObject *category, const char *message, Py_ssize_t stack_level)
 
    Issue a warning message.  The *category* argument is a warning category (see
@@ -355,18 +291,6 @@ in various ways.  There is a separate error indicator for each thread.
    is the function calling :c:func:`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, :c:func:`Py_DECREF` owned references and return
-   an error value).
-
    Warning categories must be subclasses of :c:data:`Warning`; the default warning
    category is :c:data:`RuntimeWarning`.  The standard Python warning categories are
    available as global variables whose names are ``PyExc_`` followed by the Python
@@ -410,6 +334,139 @@ in various ways.  There is a separate error indicator for each thread.
    .. versionadded:: 3.2
 
 
+Querying the error indicator
+============================
+
+.. c:function:: 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 :c:func:`PyErr_Set\*`
+   functions or to :c:func:`PyErr_Restore`).  If not set, return *NULL*.  You do not
+   own a reference to the return value, so you do not need to :c:func:`Py_DECREF`
+   it.
+
+   .. note::
+
+      Do not compare the return value to a specific exception; use
+      :c:func:`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 be a subclass of the expected exception.)
+
+
+.. c:function:: 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.
+
+
+.. c:function:: int PyErr_GivenExceptionMatches(PyObject *given, PyObject *exc)
+
+   Return true if the *given* exception matches the exception type 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 exception types in the tuple (and
+   recursively in subtuples) are searched for a match.
+
+
+.. c:function:: 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 catch exceptions or
+      by code that needs to save and restore the error indicator temporarily, e.g.::
+
+         {
+            PyObject **type, **value, **traceback;
+            PyErr_Fetch(&type, &value, &traceback);
+
+            /* ... code that might produce other errors ... */
+
+            PyErr_Restore(type, value, traceback);
+         }
+
+
+.. c:function:: 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 :c:func:`PyErr_Fetch` to save the current
+      error indicator.
+
+
+.. c:function:: void PyErr_NormalizeException(PyObject**exc, PyObject**val, PyObject**tb)
+
+   Under certain circumstances, the values returned by :c:func:`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.
+
+   .. note::
+
+      This function *does not* implicitly set the ``__traceback__``
+      attribute on the exception value. If setting the traceback
+      appropriately is desired, the following additional snippet is needed::
+
+         if (tb != NULL) {
+           PyException_SetTraceback(val, tb);
+         }
+
+
+.. c:function:: void PyErr_GetExcInfo(PyObject **ptype, PyObject **pvalue, PyObject **ptraceback)
+
+   Retrieve the exception info, as known from ``sys.exc_info()``.  This refers
+   to an exception that was *already caught*, not to an exception that was
+   freshly raised.  Returns new references for the three objects, any of which
+   may be *NULL*.  Does not modify the exception info state.
+
+   .. note::
+
+      This function is not normally used by code that wants to handle exceptions.
+      Rather, it can be used when code needs to save and restore the exception
+      state temporarily.  Use :c:func:`PyErr_SetExcInfo` to restore or clear the
+      exception state.
+
+   .. versionadded:: 3.3
+
+
+.. c:function:: void PyErr_SetExcInfo(PyObject *type, PyObject *value, PyObject *traceback)
+
+   Set the exception info, as known from ``sys.exc_info()``.  This refers
+   to an exception that was *already caught*, not to an exception that was
+   freshly raised.  This function steals the references of the arguments.
+   To clear the exception state, pass *NULL* for all three arguments.
+   For general rules about the three arguments, see :c:func:`PyErr_Restore`.
+
+   .. note::
+
+      This function is not normally used by code that wants to handle exceptions.
+      Rather, it can be used when code needs to save and restore the exception
+      state temporarily.  Use :c:func:`PyErr_GetExcInfo` to read the exception
+      state.
+
+   .. versionadded:: 3.3
+
+
+Signal Handling
+===============
+
+
 .. c:function:: int PyErr_CheckSignals()
 
    .. index::
@@ -443,13 +500,21 @@ in various ways.  There is a separate error indicator for each thread.
 
 .. c:function:: int PySignal_SetWakeupFd(int fd)
 
-   This utility function specifies a file descriptor to which a ``'\0'`` byte will
-   be written whenever a signal is received.  It returns the previous such file
-   descriptor.  The value ``-1`` disables the feature; this is the initial state.
+   This utility function specifies a file descriptor to which the signal number
+   is written as a single byte whenever a signal is received. *fd* must be
+   non-blocking. It returns the previous such file descriptor.
+
+   The value ``-1`` disables the feature; this is the initial state.
    This is equivalent to :func:`signal.set_wakeup_fd` in Python, but without any
    error checking.  *fd* should be a valid file descriptor.  The function should
    only be called from the main thread.
 
+   .. versionchanged:: 3.5
+      On Windows, the function now also supports socket handles.
+
+
+Exception Classes
+=================
 
 .. c:function:: PyObject* PyErr_NewException(char *name, PyObject *base, PyObject *dict)
 
@@ -475,18 +540,6 @@ in various ways.  There is a separate error indicator for each thread.
    .. versionadded:: 3.2
 
 
-.. c:function:: 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.
-
-
 Exception Objects
 =================
 
diff --git a/Doc/c-api/import.rst b/Doc/c-api/import.rst
index 3641fc6..01e0deb 100644
--- a/Doc/c-api/import.rst
+++ b/Doc/c-api/import.rst
@@ -183,9 +183,9 @@ Importing Modules
 
 .. c:function:: 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. Returns -1 on error.
+   Return the magic number for Python bytecode files (a.k.a. :file:`.pyc` file).
+   The magic number should be present in the first four bytes of the bytecode
+   file, in little-endian byte order. Returns -1 on error.
 
    .. versionchanged:: 3.3
       Return value of -1 upon failure.
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst
index 4d358ca..fac9b47 100644
--- a/Doc/c-api/init.rst
+++ b/Doc/c-api/init.rst
@@ -134,6 +134,9 @@ Process-wide parameters
    change for the duration of the program's execution.  No code in the Python
    interpreter will change the contents of this storage.
 
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:type:`wchar_*` string.
+
 
 .. c:function:: wchar* Py_GetProgramName()
 
@@ -245,6 +248,9 @@ Process-wide parameters
    :data:`sys.exec_prefix` to be empty.  It is up to the caller to modify these
    if required after calling :c:func:`Py_Initialize`.
 
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:type:`wchar_*` string.
+
    The path argument is copied internally, so the caller may free it after the
    call completes.
 
@@ -344,6 +350,9 @@ Process-wide parameters
      :data:`sys.path`, which is the same as prepending the current working
      directory (``"."``).
 
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:type:`wchar_*` string.
+
    .. note::
       It is recommended that applications embedding the Python interpreter
       for purposes other than executing a single script pass 0 as *updatepath*,
@@ -368,6 +377,9 @@ Process-wide parameters
    to 1 unless the :program:`python` interpreter was started with the
    :option:`-I`.
 
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:type:`wchar_*` string.
+
    .. versionchanged:: 3.4 The *updatepath* value depends on :option:`-I`.
 
 
@@ -382,6 +394,9 @@ Process-wide parameters
    execution.  No code in the Python interpreter will change the contents of
    this storage.
 
+   Use :c:func:`Py_DecodeLocale` to decode a bytes string to get a
+   :c:type:`wchar_*` string.
+
 
 .. c:function:: w_char* Py_GetPythonHome()
 
diff --git a/Doc/c-api/memory.rst b/Doc/c-api/memory.rst
index 7908622..7339006 100644
--- a/Doc/c-api/memory.rst
+++ b/Doc/c-api/memory.rst
@@ -92,8 +92,8 @@ functions are thread-safe, the :term:`GIL <global interpreter lock>` does not
 need to be held.
 
 The default raw memory block allocator uses the following functions:
-:c:func:`malloc`, :c:func:`realloc` and :c:func:`free`; call ``malloc(1)`` when
-requesting zero bytes.
+:c:func:`malloc`, :c:func:`calloc`, :c:func:`realloc` and :c:func:`free`; call
+``malloc(1)`` (or ``calloc(1, 1)``) when requesting zero bytes.
 
 .. versionadded:: 3.4
 
@@ -106,6 +106,17 @@ requesting zero bytes.
    been initialized in any way.
 
 
+.. c:function:: void* PyMem_RawCalloc(size_t nelem, size_t elsize)
+
+   Allocates *nelem* elements each whose size in bytes is *elsize* and returns
+   a pointer of type :c:type:`void\*` to the allocated memory, or *NULL* if the
+   request fails. The memory is initialized to zeros. Requesting zero elements
+   or elements of size zero bytes returns a distinct non-*NULL* pointer if
+   possible, as if ``PyMem_RawCalloc(1, 1)`` had been called instead.
+
+   .. versionadded:: 3.5
+
+
 .. c:function:: void* PyMem_RawRealloc(void *p, size_t n)
 
    Resizes the memory block pointed to by *p* to *n* bytes. The contents will
@@ -136,8 +147,8 @@ behavior when requesting zero bytes, are available for allocating and releasing
 memory from the Python heap.
 
 The default memory block allocator uses the following functions:
-:c:func:`malloc`, :c:func:`realloc` and :c:func:`free`; call ``malloc(1)`` when
-requesting zero bytes.
+:c:func:`malloc`, :c:func:`calloc`, :c:func:`realloc` and :c:func:`free`; call
+``malloc(1)`` (or ``calloc(1, 1)``) when requesting zero bytes.
 
 .. warning::
 
@@ -152,6 +163,17 @@ requesting zero bytes.
    been called instead. The memory will not have been initialized in any way.
 
 
+.. c:function:: void* PyMem_Calloc(size_t nelem, size_t elsize)
+
+   Allocates *nelem* elements each whose size in bytes is *elsize* and returns
+   a pointer of type :c:type:`void\*` to the allocated memory, or *NULL* if the
+   request fails. The memory is initialized to zeros. Requesting zero elements
+   or elements of size zero bytes returns a distinct non-*NULL* pointer if
+   possible, as if ``PyMem_Calloc(1, 1)`` had been called instead.
+
+   .. versionadded:: 3.5
+
+
 .. c:function:: void* PyMem_Realloc(void *p, size_t n)
 
    Resizes the memory block pointed to by *p* to *n* bytes. The contents will be
@@ -210,7 +232,7 @@ Customize Memory Allocators
 
 .. versionadded:: 3.4
 
-.. c:type:: PyMemAllocator
+.. c:type:: PyMemAllocatorEx
 
    Structure used to describe a memory block allocator. The structure has
    four fields:
@@ -222,11 +244,19 @@ Customize Memory Allocators
    +----------------------------------------------------------+---------------------------------------+
    | ``void* malloc(void *ctx, size_t size)``                 | allocate a memory block               |
    +----------------------------------------------------------+---------------------------------------+
+   | ``void* calloc(void *ctx, size_t nelem, size_t elsize)`` | allocate a memory block initialized   |
+   |                                                          | with zeros                            |
+   +----------------------------------------------------------+---------------------------------------+
    | ``void* realloc(void *ctx, void *ptr, size_t new_size)`` | allocate or resize a memory block     |
    +----------------------------------------------------------+---------------------------------------+
    | ``void free(void *ctx, void *ptr)``                      | free a memory block                   |
    +----------------------------------------------------------+---------------------------------------+
 
+   .. versionchanged:: 3.5
+      The :c:type:`PyMemAllocator` structure was renamed to
+      :c:type:`PyMemAllocatorEx` and a new ``calloc`` field was added.
+
+
 .. c:type:: PyMemAllocatorDomain
 
    Enum used to identify an allocator domain. Domains:
@@ -239,12 +269,12 @@ Customize Memory Allocators
      :c:func:`PyObject_Realloc` and :c:func:`PyObject_Free`
 
 
-.. c:function:: void PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocator *allocator)
+.. c:function:: void PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
 
    Get the memory block allocator of the specified domain.
 
 
-.. c:function:: void PyMem_SetAllocator(PyMemAllocatorDomain domain, PyMemAllocator *allocator)
+.. c:function:: void PyMem_SetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
 
    Set the memory block allocator of the specified domain.
 
diff --git a/Doc/c-api/number.rst b/Doc/c-api/number.rst
index 21951c3..9bcb649 100644
--- a/Doc/c-api/number.rst
+++ b/Doc/c-api/number.rst
@@ -30,6 +30,14 @@ Number Protocol
    the equivalent of the Python expression ``o1 * o2``.
 
 
+.. c:function:: PyObject* PyNumber_MatrixMultiply(PyObject *o1, PyObject *o2)
+
+   Returns the result of matrix multiplication on *o1* and *o2*, or *NULL* on
+   failure.  This is the equivalent of the Python expression ``o1 @ o2``.
+
+   .. versionadded:: 3.5
+
+
 .. c:function:: PyObject* PyNumber_FloorDivide(PyObject *o1, PyObject *o2)
 
    Return the floor of *o1* divided by *o2*, or *NULL* on failure.  This is
@@ -146,6 +154,15 @@ Number Protocol
    the Python statement ``o1 *= o2``.
 
 
+.. c:function:: PyObject* PyNumber_InPlaceMatrixMultiply(PyObject *o1, PyObject *o2)
+
+   Returns the result of matrix multiplication on *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``.
+
+   .. versionadded:: 3.5
+
+
 .. c:function:: PyObject* PyNumber_InPlaceFloorDivide(PyObject *o1, PyObject *o2)
 
    Returns the mathematical floor of dividing *o1* by *o2*, or *NULL* on failure.
diff --git a/Doc/c-api/structures.rst b/Doc/c-api/structures.rst
index 7f1cc69..b925a61 100644
--- a/Doc/c-api/structures.rst
+++ b/Doc/c-api/structures.rst
@@ -44,7 +44,7 @@ the definition of all other Python objects.
 
       PyObject ob_base;
 
-   See documentation of :c:type::`PyObject` above.
+   See documentation of :c:type:`PyObject` above.
 
 
 .. c:macro:: PyObject_VAR_HEAD
diff --git a/Doc/c-api/sys.rst b/Doc/c-api/sys.rst
index 9760dca..a6a939c 100644
--- a/Doc/c-api/sys.rst
+++ b/Doc/c-api/sys.rst
@@ -47,6 +47,60 @@ Operating System Utilities
    not call those functions directly!  :c:type:`PyOS_sighandler_t` is a typedef
    alias for :c:type:`void (\*)(int)`.
 
+.. c:function:: wchar_t* Py_DecodeLocale(const char* arg, size_t *size)
+
+   Decode a byte string from the locale encoding with the :ref:`surrogateescape
+   error handler <surrogateescape>`: undecodable bytes are decoded as
+   characters in range U+DC80..U+DCFF. If a byte sequence can be decoded as a
+   surrogate character, escape the bytes using the surrogateescape error
+   handler instead of decoding them.
+
+   Return a pointer to a newly allocated wide character string, use
+   :c:func:`PyMem_RawFree` to free the memory. If size is not ``NULL``, write
+   the number of wide characters excluding the null character into ``*size``
+
+   Return ``NULL`` on decoding error or memory allocation error. If *size* is
+   not ``NULL``, ``*size`` is set to ``(size_t)-1`` on memory error or set to
+   ``(size_t)-2`` on decoding error.
+
+   Decoding errors should never happen, unless there is a bug in the C
+   library.
+
+   Use the :c:func:`Py_EncodeLocale` function to encode the character string
+   back to a byte string.
+
+   .. seealso::
+
+      The :c:func:`PyUnicode_DecodeFSDefaultAndSize` and
+      :c:func:`PyUnicode_DecodeLocaleAndSize` functions.
+
+   .. versionadded:: 3.5
+
+
+.. c:function:: char* Py_EncodeLocale(const wchar_t *text, size_t *error_pos)
+
+   Encode a wide character string to the locale encoding with the
+   :ref:`surrogateescape error handler <surrogateescape>`: surrogate characters
+   in the range U+DC80..U+DCFF are converted to bytes 0x80..0xFF.
+
+   Return a pointer to a newly allocated byte string, use :c:func:`PyMem_Free`
+   to free the memory. Return ``NULL`` on encoding error or memory allocation
+   error
+
+   If error_pos is not ``NULL``, ``*error_pos`` is set to the index of the
+   invalid character on encoding error, or set to ``(size_t)-1`` otherwise.
+
+   Use the :c:func:`Py_DecodeLocale` function to decode the bytes string back
+   to a wide character string.
+
+   .. seealso::
+
+      The :c:func:`PyUnicode_EncodeFSDefault` and
+      :c:func:`PyUnicode_EncodeLocale` functions.
+
+   .. versionadded:: 3.5
+
+
 .. _systemfunctions:
 
 System Functions
diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst
index b43622a..eb63705 100644
--- a/Doc/c-api/typeobj.rst
+++ b/Doc/c-api/typeobj.rst
@@ -1118,6 +1118,9 @@ Number Object Structures
             binaryfunc nb_inplace_true_divide;
 
             unaryfunc nb_index;
+
+            binaryfunc nb_matrix_multiply;
+            binaryfunc nb_inplace_matrix_multiply;
        } PyNumberMethods;
 
    .. note::
diff --git a/Doc/c-api/unicode.rst b/Doc/c-api/unicode.rst
index 03c284a..00063d0 100644
--- a/Doc/c-api/unicode.rst
+++ b/Doc/c-api/unicode.rst
@@ -759,11 +759,13 @@ system.
    *errors* is ``NULL``.  *str* must end with a null character but
    cannot contain embedded null characters.
 
+   Use :c:func:`PyUnicode_DecodeFSDefaultAndSize` to decode a string from
+   :c:data:`Py_FileSystemDefaultEncoding` (the locale encoding read at
+   Python startup).
+
    .. seealso::
 
-      Use :c:func:`PyUnicode_DecodeFSDefaultAndSize` to decode a string from
-      :c:data:`Py_FileSystemDefaultEncoding` (the locale encoding read at
-      Python startup).
+      The :c:func:`Py_DecodeLocale` function.
 
    .. versionadded:: 3.3
 
@@ -784,11 +786,13 @@ system.
    *errors* is ``NULL``. Return a :class:`bytes` object. *str* cannot
    contain embedded null characters.
 
+   Use :c:func:`PyUnicode_EncodeFSDefault` to encode a string to
+   :c:data:`Py_FileSystemDefaultEncoding` (the locale encoding read at
+   Python startup).
+
    .. seealso::
 
-      Use :c:func:`PyUnicode_EncodeFSDefault` to encode a string to
-      :c:data:`Py_FileSystemDefaultEncoding` (the locale encoding read at
-      Python startup).
+      The :c:func:`Py_EncodeLocale` function.
 
    .. versionadded:: 3.3
 
@@ -833,12 +837,14 @@ used, passing :c:func:`PyUnicode_FSDecoder` as the conversion function:
    If :c:data:`Py_FileSystemDefaultEncoding` is not set, fall back to the
    locale encoding.
 
+   :c:data:`Py_FileSystemDefaultEncoding` is initialized at startup from the
+   locale encoding and cannot be modified later. If you need to decode a string
+   from the current locale encoding, use
+   :c:func:`PyUnicode_DecodeLocaleAndSize`.
+
    .. seealso::
 
-      :c:data:`Py_FileSystemDefaultEncoding` is initialized at startup from the
-      locale encoding and cannot be modified later. If you need to decode a
-      string from the current locale encoding, use
-      :c:func:`PyUnicode_DecodeLocaleAndSize`.
+      The :c:func:`Py_DecodeLocale` function.
 
    .. versionchanged:: 3.2
       Use ``"strict"`` error handler on Windows.
@@ -868,12 +874,13 @@ used, passing :c:func:`PyUnicode_FSDecoder` as the conversion function:
    If :c:data:`Py_FileSystemDefaultEncoding` is not set, fall back to the
    locale encoding.
 
+   :c:data:`Py_FileSystemDefaultEncoding` is initialized at startup from the
+   locale encoding and cannot be modified later. If you need to encode a string
+   to the current locale encoding, use :c:func:`PyUnicode_EncodeLocale`.
+
    .. seealso::
 
-      :c:data:`Py_FileSystemDefaultEncoding` is initialized at startup from the
-      locale encoding and cannot be modified later. If you need to encode a
-      string to the current locale encoding, use
-      :c:func:`PyUnicode_EncodeLocale`.
+      The :c:func:`Py_EncodeLocale` function.
 
    .. versionadded:: 3.2
 
diff --git a/Doc/conf.py b/Doc/conf.py
index f803de2..28dd80f 100644
--- a/Doc/conf.py
+++ b/Doc/conf.py
@@ -36,6 +36,9 @@ highlight_language = 'python3'
 # Require Sphinx 1.2 for build.
 needs_sphinx = '1.2'
 
+# Ignore any .rst files in the venv/ directory.
+exclude_patterns = ['venv/*']
+
 
 # Options for HTML output
 # -----------------------
diff --git a/Doc/data/refcounts.dat b/Doc/data/refcounts.dat
index 6025617..d1c24e5 100644
--- a/Doc/data/refcounts.dat
+++ b/Doc/data/refcounts.dat
@@ -349,6 +349,11 @@ PyErr_Format:PyObject*:exception:+1:
 PyErr_Format:const char*:format::
 PyErr_Format::...::
 
+PyErr_FormatV:PyObject*::null:
+PyErr_FormatV:PyObject*:exception:+1:
+PyErr_FormatV:const char*:format::
+PyErr_FormatV:va_list:vargs::
+
 PyErr_WarnEx:int:::
 PyErr_WarnEx:PyObject*:category:0:
 PyErr_WarnEx:const char*:message::
diff --git a/Doc/distutils/apiref.rst b/Doc/distutils/apiref.rst
index 82bed24..087c671 100644
--- a/Doc/distutils/apiref.rst
+++ b/Doc/distutils/apiref.rst
@@ -1099,13 +1099,13 @@ other utility module.
    during the build of Python), not the OS version of the current system.
 
    For universal binary builds on Mac OS X the architecture value reflects
-   the univeral binary status instead of the architecture of the current
+   the universal binary status instead of the architecture of the current
    processor. For 32-bit universal binaries the architecture is ``fat``,
    for 64-bit universal binaries the architecture is ``fat64``, and
    for 4-way universal binaries the architecture is ``universal``. Starting
    from Python 2.7 and Python 3.2 the architecture ``fat3`` is used for
    a 3-way universal build (ppc, i386, x86_64) and ``intel`` is used for
-   a univeral build with the i386 and x86_64 architectures
+   a universal build with the i386 and x86_64 architectures
 
    Examples of returned values on Mac OS X:
 
@@ -1193,12 +1193,12 @@ other utility module.
 
 .. 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 a :file:`__pycache__` subdirectory (see :pep:`3147`).
+   Byte-compile a collection of Python source files to :file:`.pyc` files in a
+   :file:`__pycache__` subdirectory (see :pep:`3147` and :pep:`488`).
    *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`)
+   * ``0`` - don't optimize
    * ``1`` - normal optimization (like ``python -O``)
    * ``2`` - extra optimization (like ``python -OO``)
 
@@ -1222,10 +1222,13 @@ other utility module.
    doing, leave it set to ``None``.
 
    .. versionchanged:: 3.2.3
-      Create ``.pyc`` or ``.pyo`` files with an :func:`import magic tag
+      Create ``.pyc`` files with an :func:`import magic tag
       <imp.get_tag>` in their name, in a :file:`__pycache__` subdirectory
       instead of files without tag in the current directory.
 
+   .. versionchanged: 3.5
+      Create ``.pyc`` files according to :pep:`488`.
+
 
 .. function:: rfc822_escape(header)
 
diff --git a/Doc/distutils/builtdist.rst b/Doc/distutils/builtdist.rst
index ac96c40..c5827b6 100644
--- a/Doc/distutils/builtdist.rst
+++ b/Doc/distutils/builtdist.rst
@@ -355,7 +355,7 @@ support this option, so the command::
 would create a 64bit installation executable on your 32bit version of Windows.
 
 To cross-compile, you must download the Python source code and cross-compile
-Python itself for the platform you are targetting - it is not possible from a
+Python itself for the platform you are targeting - it is not possible from a
 binary installation of Python (as the .lib etc file for other platforms are
 not included.)  In practice, this means the user of a 32 bit operating
 system will need to use Visual Studio 2008 to open the
diff --git a/Doc/distutils/introduction.rst b/Doc/distutils/introduction.rst
index 0ece646..8f46bd7 100644
--- a/Doc/distutils/introduction.rst
+++ b/Doc/distutils/introduction.rst
@@ -156,8 +156,8 @@ module
 
 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."
+   possibly associated :file:`.pyc` files).  Sometimes referred to as a
+   "pure module."
 
 extension module
    a module written in the low-level language of the Python implementation: C/C++
@@ -210,5 +210,3 @@ 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/extending/embedding.rst b/Doc/extending/embedding.rst
index 6cb686a..acd60ae 100644
--- a/Doc/extending/embedding.rst
+++ b/Doc/extending/embedding.rst
@@ -58,12 +58,18 @@ perform some operation on a file. ::
    int
    main(int argc, char *argv[])
    {
-     Py_SetProgramName(argv[0]);  /* optional but recommended */
-     Py_Initialize();
-     PyRun_SimpleString("from time import time,ctime\n"
-                        "print('Today is', ctime(time()))\n");
-     Py_Finalize();
-     return 0;
+       wchar_t *program = Py_DecodeLocale(argv[0], NULL);
+       if (program == NULL) {
+           fprintf(stderr, "Fatal error: cannot decode argv[0]\n");
+           exit(1);
+       }
+       Py_SetProgramName(program);  /* optional but recommended */
+       Py_Initialize();
+       PyRun_SimpleString("from time import time,ctime\n"
+                          "print('Today is', ctime(time()))\n");
+       Py_Finalize();
+       PyMem_RawFree(program);
+       return 0;
    }
 
 The :c:func:`Py_SetProgramName` function should be called before
@@ -160,7 +166,7 @@ for data conversion between Python and C, and for error reporting.  The
 interesting part with respect to embedding Python starts with ::
 
    Py_Initialize();
-   pName = PyUnicode_FromString(argv[1]);
+   pName = PyUnicode_DecodeFSDefault(argv[1]);
    /* Error checking of pName left out */
    pModule = PyImport_Import(pName);
 
diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst
index c10efa9..17cfdeb 100644
--- a/Doc/extending/extending.rst
+++ b/Doc/extending/extending.rst
@@ -375,11 +375,17 @@ optionally followed by an import of the module::
    int
    main(int argc, char *argv[])
    {
+       wchar_t *program = Py_DecodeLocale(argv[0], NULL);
+       if (program == NULL) {
+           fprintf(stderr, "Fatal error: cannot decode argv[0]\n");
+           exit(1);
+       }
+
        /* Add a built-in module, before Py_Initialize */
        PyImport_AppendInittab("spam", PyInit_spam);
 
        /* Pass argv[0] to the Python interpreter */
-       Py_SetProgramName(argv[0]);
+       Py_SetProgramName(program);
 
        /* Initialize the Python interpreter.  Required. */
        Py_Initialize();
@@ -391,6 +397,10 @@ optionally followed by an import of the module::
 
        ...
 
+       PyMem_RawFree(program);
+       return 0;
+   }
+
 .. note::
 
    Removing entries from ``sys.modules`` or importing compiled modules into
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index 1de86ef..57c6ddd 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -88,10 +88,17 @@ Glossary
    bytes-like object
       An object that supports the :ref:`bufferobjects`, like :class:`bytes`,
       :class:`bytearray` or :class:`memoryview`.  Bytes-like objects can
-      be used for various operations that expect binary data, such as
-      compression, saving to a binary file or sending over a socket.
-      Some operations need the binary data to be mutable, in which case
-      not all bytes-like objects can apply.
+      be used for various operations that work with binary data; these include
+      compression, saving to a binary file, and sending over a socket.
+
+      Some operations need the binary data to be mutable.  The documentation
+      often refers to these as "read-write bytes-like objects".  Example
+      mutable buffer objects include :class:`bytearray` and a
+      :class:`memoryview` of a :class:`bytearray`.
+      Other operations require the binary data to be stored in
+      immutable objects ("read-only bytes-like objects"); examples
+      of these include :class:`bytes` and a :class:`memoryview`
+      of a :class:`bytes` object.
 
    bytecode
       Python source code is compiled into bytecode, the internal representation
@@ -402,6 +409,19 @@ Glossary
       than compiled ones, though their programs generally also run more
       slowly.  See also :term:`interactive`.
 
+   interpreter shutdown
+      When asked to shut down, the Python interpreter enters a special phase
+      where it gradually releases all allocated resources, such as modules
+      and various critical internal structures.  It also makes several calls
+      to the :term:`garbage collector <garbage collection>`. This can trigger
+      the execution of code in user-defined destructors or weakref callbacks.
+      Code executed during the shutdown phase can encounter various
+      exceptions as the resources it relies on may not function anymore
+      (common examples are library modules or the warnings machinery).
+
+      The main reason for interpreter shutdown is that the ``__main__`` module
+      or the script being run has finished executing.
+
    iterable
       An object capable of returning its members one at a time. Examples of
       iterables include all sequence types (such as :class:`list`, :class:`str`,
@@ -444,12 +464,13 @@ Glossary
 
       A number of tools in Python accept key functions to control how elements
       are ordered or grouped.  They include :func:`min`, :func:`max`,
-      :func:`sorted`, :meth:`list.sort`, :func:`heapq.nsmallest`,
-      :func:`heapq.nlargest`, and :func:`itertools.groupby`.
+      :func:`sorted`, :meth:`list.sort`, :func:`heapq.merge`,
+      :func:`heapq.nsmallest`, :func:`heapq.nlargest`, and
+      :func:`itertools.groupby`.
 
       There are several ways to create a key function.  For example. the
       :meth:`str.lower` method can serve as a key function for case insensitive
-      sorts.  Alternatively, an ad-hoc key function can be built from a
+      sorts.  Alternatively, a key function can be built from a
       :keyword:`lambda` expression such as ``lambda r: (r[0], r[2])``.  Also,
       the :mod:`operator` module provides three key function constructors:
       :func:`~operator.attrgetter`, :func:`~operator.itemgetter`, and
diff --git a/Doc/howto/clinic.rst b/Doc/howto/clinic.rst
index 750ddbe..ca8e1cb 100644
--- a/Doc/howto/clinic.rst
+++ b/Doc/howto/clinic.rst
@@ -886,7 +886,7 @@ Argument Clinic generates code that does it for you (in the parsing function).
 Advanced converters
 -------------------
 
-Remeber those format units you skipped for your first
+Remember those format units you skipped for your first
 time because they were advanced?  Here's how to handle those too.
 
 The trick is, all those format units take arguments--either
@@ -1020,12 +1020,12 @@ any of the default arguments you can omit the parentheses.
 the ``"as"`` should come before the return converter.)
 
 There's one additional complication when using return converters: how do you
-indicate an error has occured?  Normally, a function returns a valid (non-``NULL``)
+indicate an error has occurred?  Normally, a function returns a valid (non-``NULL``)
 pointer for success, and ``NULL`` for failure.  But if you use an integer return converter,
 all integers are valid.  How can Argument Clinic detect an error?  Its solution: each return
 converter implicitly looks for a special value that indicates an error.  If you return
 that value, and an error has been set (``PyErr_Occurred()`` returns a true
-value), then the generated code will propogate the error.  Otherwise it will
+value), then the generated code will propagate the error.  Otherwise it will
 encode the value you return like normal.
 
 Currently Argument Clinic supports only a few return converters::
@@ -1573,7 +1573,7 @@ The fourth new directive is ``set``::
 ``line_prefix`` is a string that will be prepended to every line of Clinic's output;
 ``line_suffix`` is a string that will be appended to every line of Clinic's output.
 
-Both of these suport two format strings:
+Both of these support two format strings:
 
   ``{block comment start}``
     Turns into the string ``/*``, the start-comment text sequence for C files.
diff --git a/Doc/howto/logging-cookbook.rst b/Doc/howto/logging-cookbook.rst
index 114ec09..e31b6c2 100644
--- a/Doc/howto/logging-cookbook.rst
+++ b/Doc/howto/logging-cookbook.rst
@@ -325,6 +325,15 @@ which, when run, will produce::
 
     MainThread: Look out!
 
+.. versionchanged:: 3.5
+   Prior to Python 3.5, the :class:`QueueListener` always passed every message
+   received from the queue to every handler it was initialized with. (This was
+   because it was assumed that level filtering was all done on the other side,
+   where the queue is filled.) From 3.5 onwards, this behaviour can be changed
+   by passing a keyword argument ``respect_handler_level=True`` to the
+   listener's constructor. When this is done, the listener compares the level
+   of each message with the handler's level, and only passes a message to a
+   handler if it's appropriate to do so.
 
 .. _network-logging:
 
@@ -1680,7 +1689,7 @@ as in the following complete example::
 
     def main():
         logging.basicConfig(level=logging.INFO, format='%(message)s')
-        logging.info(_('message 1', set_value=set([1, 2, 3]), snowman='\u2603'))
+        logging.info(_('message 1', set_value={1, 2, 3}, snowman='\u2603'))
 
     if __name__ == '__main__':
         main()
diff --git a/Doc/howto/pyporting.rst b/Doc/howto/pyporting.rst
index 5e875cd..a2aaf36 100644
--- a/Doc/howto/pyporting.rst
+++ b/Doc/howto/pyporting.rst
@@ -207,13 +207,12 @@ that's ``str``/``bytes`` in Python 2 and ``bytes`` in Python 3). The following
 table lists the **unique** methods of each data type across Python 2 & 3
 (e.g., the ``decode()`` method is usable on the equivalent binary data type in
 either Python 2 or 3, but it can't be used by the text data type consistently
-between Python 2 and 3 because ``str`` in Python 3 doesn't have the method).
+between Python 2 and 3 because ``str`` in Python 3 doesn't have the method). Do
+note that as of Python 3.5 the ``__mod__`` method was added to the bytes type.
 
 ======================== =====================
 **Text data**            **Binary data**
 ------------------------ ---------------------
-__mod__ (``%`` operator)
------------------------- ---------------------
 \                        decode
 ------------------------ ---------------------
 encode
@@ -348,10 +347,12 @@ tox with your continuous integration system so that you never accidentally break
 Python 2 or 3 support.
 
 You may also want to use use the ``-bb`` flag with the Python 3 interpreter to
-trigger an exception when you are comparing bytes to strings. Usually it's
-simply ``False``, but if you made a mistake in your separation of text/binary
-data handling you may be accidentally comparing text and binary data. This flag
-will raise an exception when that occurs to help track down such cases.
+trigger an exception when you are comparing bytes to strings or bytes to an int
+(the latter is available starting in Python 3.5). By default type-differing
+comparisons simply return ``False``, but if you made a mistake in your
+separation of text/binary data handling or indexing on bytes you wouldn't easily
+find the mistake. This flag will raise an exception when these kinds of
+comparisons occur, making the mistake much easier to track down.
 
 And that's mostly it! At this point your code base is compatible with both
 Python 2 and 3 simultaneously. Your testing will also be set up so that you
diff --git a/Doc/howto/regex.rst b/Doc/howto/regex.rst
index fbe763b..ad2c6ab 100644
--- a/Doc/howto/regex.rst
+++ b/Doc/howto/regex.rst
@@ -852,7 +852,7 @@ 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 is well-known for its powerful additions to standard regular expressions.
+Perl 5 is well known for its powerful additions to standard regular expressions.
 For these new features the Perl developers couldn't choose new single-keystroke metacharacters
 or new special sequences beginning with ``\`` without making Perl's regular
 expressions confusingly different from standard REs.  If they chose ``&`` as a
@@ -1138,7 +1138,7 @@ Empty matches are replaced only when they're not adjacent to a previous match.
 
 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.
+carriage return, and so forth. Unknown escapes such as ``\&`` 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.
diff --git a/Doc/howto/sockets.rst b/Doc/howto/sockets.rst
index d5aff90..04394d4 100644
--- a/Doc/howto/sockets.rst
+++ b/Doc/howto/sockets.rst
@@ -234,7 +234,7 @@ messages to be sent back to back (without some kind of reply), and you pass
 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
+Prefixing the message with its 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
diff --git a/Doc/howto/unicode.rst b/Doc/howto/unicode.rst
index b49ac39..ee31a9c 100644
--- a/Doc/howto/unicode.rst
+++ b/Doc/howto/unicode.rst
@@ -280,8 +280,9 @@ and optionally an *errors* argument.
 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 :exc:`UnicodeDecodeError` exception), ``'replace'`` (use
-``U+FFFD``, ``REPLACEMENT CHARACTER``), or ``'ignore'`` (just leave the
-character out of the Unicode result).
+``U+FFFD``, ``REPLACEMENT CHARACTER``), ``'ignore'`` (just leave the
+character out of the Unicode result), or ``'backslashreplace'`` (inserts a
+``\xNN`` escape sequence).
 The following examples show the differences::
 
     >>> b'\x80abc'.decode("utf-8", "strict")  #doctest: +NORMALIZE_WHITESPACE
@@ -291,6 +292,8 @@ The following examples show the differences::
       invalid start byte
     >>> b'\x80abc'.decode("utf-8", "replace")
     '\ufffdabc'
+    >>> b'\x80abc'.decode("utf-8", "backslashreplace")
+    '\\x80abc'
     >>> b'\x80abc'.decode("utf-8", "ignore")
     'abc'
 
@@ -325,8 +328,9 @@ The *errors* parameter is the same as the parameter of the
 :meth:`~bytes.decode` method but supports a few more possible handlers. As well as
 ``'strict'``, ``'ignore'``, and ``'replace'`` (which in this case
 inserts a question mark instead of the unencodable character), there is
-also ``'xmlcharrefreplace'`` (inserts an XML character reference) and
-``backslashreplace`` (inserts a ``\uNNNN`` escape sequence).
+also ``'xmlcharrefreplace'`` (inserts an XML character reference),
+``backslashreplace`` (inserts a ``\uNNNN`` escape sequence) and
+``namereplace`` (inserts a ``\N{...}`` escape sequence).
 
 The following example shows the different results::
 
@@ -346,6 +350,8 @@ The following example shows the different results::
     b'&#40960;abcd&#1972;'
     >>> u.encode('ascii', 'backslashreplace')
     b'\\ua000abcd\\u07b4'
+    >>> u.encode('ascii', 'namereplace')
+    b'\\N{YI SYLLABLE IT}abcd\\u07b4'
 
 The low-level routines for registering and accessing the available
 encodings are found in the :mod:`codecs` module.  Implementing new
diff --git a/Doc/includes/noddy.c b/Doc/includes/noddy.c
index 8f79fcf..19a27a8 100644
--- a/Doc/includes/noddy.c
+++ b/Doc/includes/noddy.c
@@ -38,7 +38,7 @@ static PyModuleDef noddymodule = {
 };
 
 PyMODINIT_FUNC
-PyInit_noddy(void) 
+PyInit_noddy(void)
 {
     PyObject* m;
 
diff --git a/Doc/includes/run-func.c b/Doc/includes/run-func.c
index 1c9860d..986d670 100644
--- a/Doc/includes/run-func.c
+++ b/Doc/includes/run-func.c
@@ -13,7 +13,7 @@ main(int argc, char *argv[])
     }
 
     Py_Initialize();
-    pName = PyUnicode_FromString(argv[1]);
+    pName = PyUnicode_DecodeFSDefault(argv[1]);
     /* Error checking of pName left out */
 
     pModule = PyImport_Import(pName);
diff --git a/Doc/install/index.rst b/Doc/install/index.rst
index 8f3ad72..876f350 100644
--- a/Doc/install/index.rst
+++ b/Doc/install/index.rst
@@ -361,7 +361,7 @@ And here are the values used on Windows:
 Type of file    Installation directory
 =============== ===========================================================
 modules         :file:`{userbase}\\Python{XY}\\site-packages`
-scripts         :file:`{userbase}\\Scripts`
+scripts         :file:`{userbase}\\Python{XY}\\Scripts`
 data            :file:`{userbase}`
 C headers       :file:`{userbase}\\Python{XY}\\Include\\{distname}`
 =============== ===========================================================
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 73f9480..24060f0 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -135,7 +135,7 @@ ArgumentParser objects
                           formatter_class=argparse.HelpFormatter, \
                           prefix_chars='-', fromfile_prefix_chars=None, \
                           argument_default=None, conflict_handler='error', \
-                          add_help=True)
+                          add_help=True, allow_abbrev=True)
 
    Create a new :class:`ArgumentParser` object. All parameters should be passed
    as keyword arguments. Each parameter has its own more detailed description
@@ -169,6 +169,12 @@ ArgumentParser objects
 
    * add_help_ - Add a -h/--help option to the parser (default: ``True``)
 
+   * allow_abbrev_ - Allows long options to be abbreviated if the
+     abbreviation is unambiguous. (default: ``True``)
+
+   .. versionchanged:: 3.5
+      *allow_abbrev* parameter was added.
+
 The following sections describe how each of these are used.
 
 
@@ -518,6 +524,26 @@ calls, we supply ``argument_default=SUPPRESS``::
    >>> parser.parse_args([])
    Namespace()
 
+.. _allow_abbrev:
+
+allow_abbrev
+^^^^^^^^^^^^
+
+Normally, when you pass an argument list to the
+:meth:`~ArgumentParser.parse_args` method of a :class:`ArgumentParser`,
+it :ref:`recognizes abbreviations <prefix-matching>` of long options.
+
+This feature can be disabled by setting ``allow_abbrev`` to ``False``::
+
+   >>> parser = argparse.ArgumentParser(prog='PROG', allow_abbrev=False)
+   >>> parser.add_argument('--foobar', action='store_true')
+   >>> parser.add_argument('--foonley', action='store_false')
+   >>> parser.parse_args(['--foon'])
+   usage: PROG [-h] [--foobar] [--foonley]
+   PROG: error: unrecognized arguments: --foon
+
+.. versionadded:: 3.5
+
 
 conflict_handler
 ^^^^^^^^^^^^^^^^
@@ -1410,9 +1436,9 @@ argument::
 Argument abbreviations (prefix matching)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-The :meth:`~ArgumentParser.parse_args` method allows long options to be
-abbreviated to a prefix, if the abbreviation is unambiguous (the prefix matches
-a unique option)::
+The :meth:`~ArgumentParser.parse_args` method :ref:`by default <allow_abbrev>`
+allows long options to be abbreviated to a prefix, if the abbreviation is
+unambiguous (the prefix matches a unique option)::
 
    >>> parser = argparse.ArgumentParser(prog='PROG')
    >>> parser.add_argument('-bacon')
@@ -1426,6 +1452,7 @@ a unique option)::
    PROG: error: ambiguous option: -ba could match -badger, -bacon
 
 An error is produced for arguments that could produce more than one options.
+This feature can be disabled by setting :ref:`allow_abbrev` to ``False``.
 
 
 Beyond ``sys.argv``
@@ -1910,7 +1937,7 @@ Customizing file parsing
 
    Arguments that are read from a file (see the *fromfile_prefix_chars*
    keyword argument to the :class:`ArgumentParser` constructor) are read one
-   argument per line. :meth:`convert_arg_line_to_args` can be overriden for
+   argument per line. :meth:`convert_arg_line_to_args` can be overridden for
    fancier reading.
 
    This method takes a single argument *arg_line* which is a string read from
diff --git a/Doc/library/asynchat.rst b/Doc/library/asynchat.rst
index c6fa061..794da8c 100644
--- a/Doc/library/asynchat.rst
+++ b/Doc/library/asynchat.rst
@@ -147,40 +147,6 @@ connection requests.
    by the channel after :meth:`found_terminator` is called.
 
 
-asynchat - Auxiliary Classes
-------------------------------------------
-
-.. class:: fifo(list=None)
-
-   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:: is_empty()
-
-      Returns ``True`` if and only if the fifo is empty.
-
-
-   .. method:: first()
-
-      Returns the least-recently :meth:`push`\ ed item from the fifo.
-
-
-   .. method:: push(data)
-
-      Adds the given data (which may be a string or a producer object) to the
-      producer fifo.
-
-
-   .. method:: pop()
-
-      If the fifo is not empty, returns ``True, first()``, deleting the popped
-      item.  Returns ``False, None`` for an empty fifo.
-
-
 .. _asynchat-example:
 
 asynchat Example
diff --git a/Doc/library/asyncio-eventloops.rst b/Doc/library/asyncio-eventloops.rst
index afb8b9f..ae3bf90 100644
--- a/Doc/library/asyncio-eventloops.rst
+++ b/Doc/library/asyncio-eventloops.rst
@@ -100,8 +100,6 @@ Common limits of Windows event loops:
 
 :class:`ProactorEventLoop` specific limits:
 
-- SSL is not supported: :meth:`~BaseEventLoop.create_connection` and
-  :meth:`~BaseEventLoop.create_server` cannot be used with SSL for example
 - :meth:`~BaseEventLoop.create_datagram_endpoint` (UDP) is not supported
 - :meth:`~BaseEventLoop.add_reader` and :meth:`~BaseEventLoop.add_writer` are
   not supported
@@ -112,6 +110,10 @@ The best resolution is 0.5 msec. The resolution depends on the hardware
 <http://fr.wikipedia.org/wiki/High_Precision_Event_Timer>`_) and on the Windows
 configuration. See :ref:`asyncio delayed calls <asyncio-delayed-calls>`.
 
+.. versionchanged:: 3.5
+
+   :class:`ProactorEventLoop` now supports SSL.
+
 
 Mac OS X
 ^^^^^^^^
diff --git a/Doc/library/asyncio-queue.rst b/Doc/library/asyncio-queue.rst
index 3370672..f11c09a 100644
--- a/Doc/library/asyncio-queue.rst
+++ b/Doc/library/asyncio-queue.rst
@@ -8,7 +8,6 @@ Queues:
 * :class:`Queue`
 * :class:`PriorityQueue`
 * :class:`LifoQueue`
-* :class:`JoinableQueue`
 
 asyncio queue API was designed to be close to classes of the :mod:`queue`
 module (:class:`~queue.Queue`, :class:`~queue.PriorityQueue`,
@@ -144,16 +143,6 @@ LifoQueue
     first.
 
 
-JoinableQueue
-^^^^^^^^^^^^^
-
-.. class:: JoinableQueue
-
-   Deprecated alias for :class:`Queue`.
-
-   .. deprecated:: 3.4.4
-
-
 Exceptions
 ^^^^^^^^^^
 
diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst
index 488cda5..1b8d9cf 100644
--- a/Doc/library/bz2.rst
+++ b/Doc/library/bz2.rst
@@ -120,6 +120,10 @@ All of the classes in this module may safely be accessed from multiple threads.
    .. versionchanged:: 3.4
       The ``'x'`` (exclusive creation) mode was added.
 
+   .. versionchanged:: 3.5
+      The :meth:`~io.BufferedIOBase.read` method now accepts an argument of
+      ``None``.
+
 
 Incremental (de)compression
 ---------------------------
@@ -162,15 +166,32 @@ Incremental (de)compression
       you need to decompress a multi-stream input with :class:`BZ2Decompressor`,
       you must use a new decompressor for each stream.
 
-   .. method:: decompress(data)
+   .. method:: decompress(data, max_length=-1)
+
+      Decompress *data* (a :term:`bytes-like object`), returning
+      uncompressed data as bytes. Some of *data* may be buffered
+      internally, for use in later calls to :meth:`decompress`. The
+      returned data should be concatenated with the output of any
+      previous calls to :meth:`decompress`.
+
+      If *max_length* is nonnegative, returns at most *max_length*
+      bytes of decompressed data. If this limit is reached and further
+      output can be produced, the :attr:`~.needs_input` attribute will
+      be set to ``False``. In this case, the next call to
+      :meth:`~.decompress` may provide *data* as ``b''`` to obtain
+      more of the output.
 
-      Provide data to the decompressor object. Returns a chunk of decompressed
-      data if possible, or an empty byte string otherwise.
+      If all of the input data was decompressed and returned (either
+      because this was less than *max_length* bytes, or because
+      *max_length* was negative), the :attr:`~.needs_input` attribute
+      will be set to ``True``.
 
-      Attempting to decompress data after the end of the current stream is
-      reached raises an :exc:`EOFError`. If any data is found after the end of
-      the stream, it is ignored and saved in the :attr:`unused_data` attribute.
+      Attempting to decompress data after the end of stream is reached
+      raises an `EOFError`.  Any data found after the end of the
+      stream is ignored and saved in the :attr:`~.unused_data` attribute.
 
+      .. versionchanged:: 3.5
+         Added the *max_length* parameter.
 
    .. attribute:: eof
 
@@ -186,6 +207,13 @@ Incremental (de)compression
       If this attribute is accessed before the end of the stream has been
       reached, its value will be ``b''``.
 
+   .. attribute:: needs_input
+
+      ``False`` if the :meth:`.decompress` method can provide more
+      decompressed data before requiring new uncompressed input.
+
+      .. versionadded:: 3.5
+
 
 One-shot (de)compression
 ------------------------
diff --git a/Doc/library/cgi.rst b/Doc/library/cgi.rst
index fa13145..0a9e884 100644
--- a/Doc/library/cgi.rst
+++ b/Doc/library/cgi.rst
@@ -157,6 +157,9 @@ return bytes)::
            if not line: break
            linecount = linecount + 1
 
+:class:`FieldStorage` objects also support being used in a :keyword:`with`
+statement, which will automatically close them when done.
+
 If an error is encountered when obtaining the contents of an uploaded file
 (for example, when the user interrupts the form submission by clicking on
 a Back or Cancel button) the :attr:`~FieldStorage.done` attribute of the
@@ -182,6 +185,10 @@ A form submitted via POST that also has a query string will contain both
    The :attr:`~FieldStorage.file` attribute is automatically closed upon the
    garbage collection of the creating :class:`FieldStorage` instance.
 
+.. versionchanged:: 3.5
+   Added support for the context management protocol to the
+   :class:`FieldStorage` class.
+
 
 Higher Level Interface
 ----------------------
diff --git a/Doc/library/cmd.rst b/Doc/library/cmd.rst
index 80d2a5d..1ab2d74 100644
--- a/Doc/library/cmd.rst
+++ b/Doc/library/cmd.rst
@@ -259,7 +259,7 @@ immediate playback::
             'Move turtle to an absolute position with changing orientation.  GOTO 100 200'
             goto(*parse(arg))
         def do_home(self, arg):
-            'Return turtle to the home postion:  HOME'
+            'Return turtle to the home position:  HOME'
             home()
         def do_circle(self, arg):
             'Draw circle with given radius an options extent and steps:  CIRCLE 50'
diff --git a/Doc/library/code.rst b/Doc/library/code.rst
index 5b5d7cc..275201c 100644
--- a/Doc/library/code.rst
+++ b/Doc/library/code.rst
@@ -4,6 +4,7 @@
 .. module:: code
    :synopsis: Facilities to implement read-eval-print loops.
 
+**Source code:** :source:`Lib/code.py`
 
 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
@@ -113,6 +114,9 @@ Interactive Interpreter Objects
    because it is within the interpreter object implementation. The output is
    written by the :meth:`write` method.
 
+   .. versionchanged:: 3.5 The full chained traceback is displayed instead
+      of just the primary traceback.
+
 
 .. method:: InteractiveInterpreter.write(data)
 
@@ -165,4 +169,3 @@ interpreter objects as well as the following additions.
    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
index 19d7192..0430cb9 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -7,6 +7,7 @@
 .. sectionauthor:: Marc-André Lemburg <mal@lemburg.com>
 .. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
 
+**Source code:** :source:`Lib/codecs.py`
 
 .. index::
    single: Unicode
@@ -29,10 +30,9 @@ module features are restricted to use specifically with
 The module defines the following functions for encoding and decoding with
 any codec:
 
-.. function:: encode(obj, [encoding[, errors]])
+.. function:: encode(obj, encoding='utf-8', errors='strict')
 
-   Encodes *obj* using the codec registered for *encoding*. The default
-   encoding is ``utf-8``.
+   Encodes *obj* using the codec registered for *encoding*.
 
    *Errors* may be given to set the desired error handling scheme. The
    default error handler is ``'strict'`` meaning that encoding errors raise
@@ -40,10 +40,9 @@ any codec:
    :exc:`UnicodeEncodeError`). Refer to :ref:`codec-base-classes` for more
    information on codec error handling.
 
-.. function:: decode(obj, [encoding[, errors]])
+.. function:: decode(obj, encoding='utf-8', errors='strict')
 
-   Decodes *obj* using the codec registered for *encoding*. The default
-   encoding is ``utf-8``.
+   Decodes *obj* using the codec registered for *encoding*.
 
    *Errors* may be given to set the desired error handling scheme. The
    default error handler is ``'strict'`` meaning that decoding errors raise
@@ -104,7 +103,6 @@ The full details for each codec can also be looked up directly:
 To simplify access to the various codec components, 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.
@@ -274,6 +272,7 @@ implement the file protocols. Codec authors also need to define how the
 codec will handle encoding and decoding errors.
 
 
+.. _surrogateescape:
 .. _error-handlers:
 
 Error Handlers
@@ -315,10 +314,14 @@ The following error handlers are only applicable to
 |                         | reference (only for encoding).  Implemented   |
 |                         | in :func:`xmlcharrefreplace_errors`.          |
 +-------------------------+-----------------------------------------------+
-| ``'backslashreplace'``  | Replace with backslashed escape sequences     |
-|                         | (only for encoding).  Implemented in          |
+| ``'backslashreplace'``  | Replace with backslashed escape sequences.    |
+|                         | Implemented in                                |
 |                         | :func:`backslashreplace_errors`.              |
 +-------------------------+-----------------------------------------------+
+| ``'namereplace'``       | Replace with ``\N{...}`` escape sequences     |
+|                         | (only for encoding).  Implemented in          |
+|                         | :func:`namereplace_errors`.                   |
++-------------------------+-----------------------------------------------+
 | ``'surrogateescape'``   | On decoding, replace byte with individual     |
 |                         | surrogate code ranging from ``U+DC80`` to     |
 |                         | ``U+DCFF``.  This code will then be turned    |
@@ -344,6 +347,13 @@ In addition, the following error handler is specific to the given codecs:
 .. versionchanged:: 3.4
    The ``'surrogatepass'`` error handlers now works with utf-16\* and utf-32\* codecs.
 
+.. versionadded:: 3.5
+   The ``'namereplace'`` error handler.
+
+.. versionchanged:: 3.5
+   The ``'backslashreplace'`` error handlers now works with decoding and
+   translating.
+
 The set of allowed values can be extended by registering a new named error
 handler:
 
@@ -411,9 +421,17 @@ functions:
 
 .. function:: backslashreplace_errors(exception)
 
-   Implements the ``'backslashreplace'`` error handling (for encoding with
+   Implements the ``'backslashreplace'`` error handling (for
+   :term:`text encodings <text encoding>` only): malformed data is
+   replaced by a backslashed escape sequence.
+
+.. function:: namereplace_errors(exception)
+
+   Implements the ``'namereplace'`` error handling (for encoding with
    :term:`text encodings <text encoding>` only): the
-   unencodable character is replaced by a backslashed escape sequence.
+   unencodable character is replaced by a ``\N{...}`` escape sequence.
+
+   .. versionadded:: 3.5
 
 
 .. _codec-objects:
@@ -1444,4 +1462,3 @@ 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/collections.abc.rst b/Doc/library/collections.abc.rst
index 599e9fa..99c4311 100644
--- a/Doc/library/collections.abc.rst
+++ b/Doc/library/collections.abc.rst
@@ -179,7 +179,7 @@ Notes on using :class:`Set` and :class:`MutableSet` as a mixin:
 (3)
    The :class:`Set` mixin provides a :meth:`_hash` method to compute a hash value
    for the set; however, :meth:`__hash__` is not defined because not all sets
-   are hashable or immutable.  To add set hashabilty using mixins,
+   are hashable or immutable.  To add set hashability using mixins,
    inherit from both :meth:`Set` and :meth:`Hashable`, then define
    ``__hash__ = Set._hash``.
 
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 0acde12..dd6395d 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -437,6 +437,13 @@ or subtracting from an empty counter.
         Remove all elements from the deque leaving it with length 0.
 
 
+    .. method:: copy()
+
+        Create a shallow copy of the deque.
+
+        .. versionadded:: 3.5
+
+
     .. method:: count(x)
 
         Count the number of deque elements equal to *x*.
@@ -457,6 +464,21 @@ or subtracting from an empty counter.
         elements in the iterable argument.
 
 
+    .. method:: index(x[, start[, end]])
+
+        Return the position of *x* in the deque.  Returns the first match
+        or raises :exc:`ValueError` if not found.
+
+        .. versionadded:: 3.5
+
+
+    .. method:: insert(i, x)
+
+        Insert *x* into the deque at position *i*.
+
+        .. versionadded:: 3.5
+
+
     .. method:: pop()
 
         Remove and return an element from the right side of the deque. If no
@@ -504,6 +526,9 @@ the :keyword:`in` operator, and subscript references such as ``d[-1]``.  Indexed
 access is O(1) at both ends but slows to O(n) in the middle.  For fast random
 access, use lists instead.
 
+Starting in version 3.5, deques support ``__add__()``, ``__mul__()``,
+and ``__imul__()``.
+
 Example:
 
 .. doctest::
@@ -982,12 +1007,15 @@ The :class:`OrderedDict` constructor and :meth:`update` method both accept
 keyword arguments, but their order is lost because Python's function call
 semantics pass-in keyword arguments using a regular unordered dictionary.
 
+.. versionchanged:: 3.5
+   The items, keys, and values :term:`views <view>` of :class:`OrderedDict` now
+   support reverse iteration using :func:`reversed`.
 
 :class:`OrderedDict` Examples and Recipes
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Since an ordered dictionary remembers its insertion order, it can be used
-in conjuction with sorting to make a sorted dictionary::
+in conjunction with sorting to make a sorted dictionary::
 
     >>> # regular unsorted dictionary
     >>> d = {'banana': 3, 'apple':4, 'pear': 1, 'orange': 2}
diff --git a/Doc/library/compileall.rst b/Doc/library/compileall.rst
index 9712de2..57f4804 100644
--- a/Doc/library/compileall.rst
+++ b/Doc/library/compileall.rst
@@ -42,7 +42,8 @@ compile Python sources.
 
 .. cmdoption:: -q
 
-   Do not print the list of files compiled, print only error messages.
+   Do not print the list of files compiled. If passed once, error messages will
+   still be printed. If passed twice (``-qq``), all output is suppressed.
 
 .. cmdoption:: -d destdir
 
@@ -70,9 +71,33 @@ compile Python sources.
    is to write files to their :pep:`3147` locations and names, which allows
    byte-code files from multiple versions of Python to coexist.
 
+.. cmdoption:: -r
+
+   Control the maximum recursion level for subdirectories.
+   If this is given, then ``-l`` option will not be taken into account.
+   :program:`python -m compileall <directory> -r 0` is equivalent to
+   :program:`python -m compileall <directory> -l`.
+
+.. cmdoption:: -j N
+
+   Use *N* workers to compile the files within the given directory.
+   If ``0`` is used, then the result of :func:`os.cpu_count()`
+   will be used.
+
 .. versionchanged:: 3.2
    Added the ``-i``, ``-b`` and ``-h`` options.
 
+.. versionchanged:: 3.5
+   Added the  ``-j`` and ``-r`` options.
+
+.. versionchanged:: 3.5
+   ``-q`` option was changed to a multilevel value.
+
+.. versionchanged:: 3.5
+   ``-b`` will always produce a byte-code file ending in ``.pyc``, never
+   ``.pyo``.
+
+
 There is no command-line option to control the optimization level used by the
 :func:`compile` function, because the Python interpreter itself already
 provides the option: :program:`python -O -m compileall`.
@@ -80,7 +105,7 @@ provides the option: :program:`python -O -m compileall`.
 Public functions
 ----------------
 
-.. function:: compile_dir(dir, maxlevels=10, ddir=None, force=False, rx=None, quiet=False, legacy=False, optimize=-1)
+.. function:: compile_dir(dir, maxlevels=10, ddir=None, force=False, rx=None, quiet=0, legacy=False, optimize=-1, workers=1)
 
    Recursively descend the directory tree named by *dir*, compiling all :file:`.py`
    files along the way.
@@ -101,8 +126,9 @@ Public functions
    file considered for compilation, and if it returns a true value, the file
    is skipped.
 
-   If *quiet* is true, nothing is printed to the standard output unless errors
-   occur.
+   If *quiet* is ``False`` or ``0`` (the default), the filenames and other
+   information are printed to standard out. Set to ``1``, only errors are
+   printed. Set to ``2``, all output is suppressed.
 
    If *legacy* is true, byte-code files are written to their legacy locations
    and names, which may overwrite byte-code files created by another version of
@@ -113,11 +139,26 @@ Public functions
    *optimize* specifies the optimization level for the compiler.  It is passed to
    the built-in :func:`compile` function.
 
+   The argument *workers* specifies how many workers are used to
+   compile files in parallel. The default is to not use multiple workers.
+   If the platform can't use multiple workers and *workers* argument is given,
+   then a :exc:`NotImplementedError` will be raised.
+   If *workers* is lower than ``0``, a :exc:`ValueError` will be raised.
+
    .. versionchanged:: 3.2
       Added the *legacy* and *optimize* parameter.
 
+   .. versionchanged:: 3.5
+      Added the *workers* parameter.
+
+   .. versionchanged:: 3.5
+      *quiet* parameter was changed to a multilevel value.
 
-.. function:: compile_file(fullname, ddir=None, force=False, rx=None, quiet=False, legacy=False, optimize=-1)
+   .. versionchanged:: 3.5
+      The *legacy* parameter only writes out ``.pyc`` files, not ``.pyo`` files
+      no matter what the value of *optimize* is.
+
+.. function:: compile_file(fullname, ddir=None, force=False, rx=None, quiet=0, legacy=False, optimize=-1)
 
    Compile the file with path *fullname*.
 
@@ -131,8 +172,9 @@ Public functions
    file being compiled, and if it returns a true value, the file is not
    compiled and ``True`` is returned.
 
-   If *quiet* is true, nothing is printed to the standard output unless errors
-   occur.
+   If *quiet* is ``False`` or ``0`` (the default), the filenames and other
+   information are printed to standard out. Set to ``1``, only errors are
+   printed. Set to ``2``, all output is suppressed.
 
    If *legacy* is true, byte-code files are written to their legacy locations
    and names, which may overwrite byte-code files created by another version of
@@ -145,8 +187,14 @@ Public functions
 
    .. versionadded:: 3.2
 
+   .. versionchanged:: 3.5
+      *quiet* parameter was changed to a multilevel value.
+
+   .. versionchanged:: 3.5
+      The *legacy* parameter only writes out ``.pyc`` files, not ``.pyo`` files
+      no matter what the value of *optimize* is.
 
-.. function:: compile_path(skip_curdir=True, maxlevels=0, force=False, legacy=False, optimize=-1)
+.. function:: compile_path(skip_curdir=True, maxlevels=0, force=False, quiet=0, legacy=False, optimize=-1)
 
    Byte-compile all the :file:`.py` files found along ``sys.path``. If
    *skip_curdir* is true (the default), the current directory is not included
@@ -157,6 +205,12 @@ Public functions
    .. versionchanged:: 3.2
       Added the *legacy* and *optimize* parameter.
 
+   .. versionchanged:: 3.5
+      *quiet* parameter was changed to a multilevel value.
+
+   .. versionchanged:: 3.5
+      The *legacy* parameter only writes out ``.pyc`` files, not ``.pyo`` files
+      no matter what the value of *optimize* is.
 
 To force a recompile of all the :file:`.py` files in the :file:`Lib/`
 subdirectory and all its subdirectories::
diff --git a/Doc/library/concurrent.futures.rst b/Doc/library/concurrent.futures.rst
index 48b4362..11b3916 100644
--- a/Doc/library/concurrent.futures.rst
+++ b/Doc/library/concurrent.futures.rst
@@ -38,7 +38,7 @@ Executor Objects
               future = executor.submit(pow, 323, 1235)
               print(future.result())
 
-    .. method:: map(func, *iterables, timeout=None)
+    .. method:: map(func, *iterables, timeout=None, chunksize=1)
 
        Equivalent to :func:`map(func, *iterables) <map>` except *func* is executed
        asynchronously and several calls to *func* may be made concurrently.  The
@@ -48,7 +48,16 @@ Executor Objects
        *timeout* can be an int or a float.  If *timeout* is not specified or
        ``None``, there is no limit to the wait time.  If a call raises an
        exception, then that exception will be raised when its value is
-       retrieved from the iterator.
+       retrieved from the iterator. When using :class:`ProcessPoolExecutor`, this
+       method chops *iterables* into a number of chunks which it submits to the
+       pool as separate tasks. The (approximate) size of these chunks can be
+       specified by setting *chunksize* to a positive integer. For very long
+       iterables, using a large value for *chunksize* can significantly improve
+       performance compared to the default size of 1. With :class:`ThreadPoolExecutor`,
+       *chunksize* has no effect.
+
+       .. versionchanged:: 3.5
+          Added the *chunksize* argument.
 
     .. method:: shutdown(wait=True)
 
@@ -115,11 +124,19 @@ And::
    executor.submit(wait_on_future)
 
 
-.. class:: ThreadPoolExecutor(max_workers)
+.. class:: ThreadPoolExecutor(max_workers=None)
 
    An :class:`Executor` subclass that uses a pool of at most *max_workers*
    threads to execute calls asynchronously.
 
+   .. versionchanged:: 3.5
+      If *max_workers* is ``None`` or
+      not given, it will default to the number of processors on the machine,
+      multiplied by ``5``, assuming that :class:`ThreadPoolExecutor` is often
+      used to overlap I/O instead of CPU work and the number of workers
+      should be higher than the number of workers
+      for :class:`ProcessPoolExecutor`.
+
 
 .. _threadpoolexecutor-example:
 
@@ -175,6 +192,8 @@ to a :class:`ProcessPoolExecutor` will result in deadlock.
    An :class:`Executor` subclass that executes calls asynchronously using a pool
    of at most *max_workers* processes.  If *max_workers* is ``None`` or not
    given, it will default to the number of processors on the machine.
+   If *max_workers* is lower or equal to ``0``, then a :exc:`ValueError`
+   will be raised.
 
    .. versionchanged:: 3.3
       When one of the worker processes terminates abruptly, a
diff --git a/Doc/library/configparser.rst b/Doc/library/configparser.rst
index 024d27c..c9187a3 100644
--- a/Doc/library/configparser.rst
+++ b/Doc/library/configparser.rst
@@ -11,6 +11,8 @@
 .. sectionauthor:: Christopher G. Petrilli <petrilli@amber.org>
 .. sectionauthor:: Łukasz Langa <lukasz@langa.pl>
 
+**Source code:** :source:`Lib/configparser.py`
+
 .. index::
    pair: .ini; file
    pair: configuration; file
@@ -142,12 +144,13 @@ datatypes, you should convert on your own:
    >>> float(topsecret['CompressionLevel'])
    9.0
 
-Extracting Boolean values is not that simple, though.  Passing the value
-to ``bool()`` would do no good since ``bool('False')`` is still
-``True``.  This is why config parsers also provide :meth:`getboolean`.
-This method is case-insensitive and recognizes Boolean values from
-``'yes'``/``'no'``, ``'on'``/``'off'`` and ``'1'``/``'0'`` [1]_.
-For example:
+Since this task is so common, config parsers provide a range of handy getter
+methods to handle integers, floats and booleans.  The last one is the most
+interesting because simply passing the value to ``bool()`` would do no good
+since ``bool('False')`` is still ``True``.  This is why config parsers also
+provide :meth:`getboolean`.  This method is case-insensitive and recognizes
+Boolean values from ``'yes'``/``'no'``, ``'on'``/``'off'``,
+``'true'``/``'false'`` and ``'1'``/``'0'`` [1]_.  For example:
 
 .. doctest::
 
@@ -159,10 +162,8 @@ For example:
    True
 
 Apart from :meth:`getboolean`, config parsers also provide equivalent
-:meth:`getint` and :meth:`getfloat` methods, but these are far less
-useful since conversion using :func:`int` and :func:`float` is
-sufficient for these types.
-
+:meth:`getint` and :meth:`getfloat` methods.  You can register your own
+converters and customize the provided ones. [1]_
 
 Fallback Values
 ---------------
@@ -317,11 +318,11 @@ from ``get()`` calls.
 .. class:: ExtendedInterpolation()
 
    An alternative handler for interpolation which implements a more advanced
-   syntax, used for instance in ``zc.buildout``. Extended interpolation is
+   syntax, used for instance in ``zc.buildout``.  Extended interpolation is
    using ``${section:option}`` to denote a value from a foreign section.
-   Interpolation can span multiple levels. For convenience, if the ``section:``
-   part is omitted, interpolation defaults to the current section (and possibly
-   the default values from the special section).
+   Interpolation can span multiple levels.  For convenience, if the
+   ``section:`` part is omitted, interpolation defaults to the current section
+   (and possibly the default values from the special section).
 
    For example, the configuration specified above with basic interpolation,
    would look like this with extended interpolation:
@@ -386,7 +387,7 @@ However, there are a few differences that should be taken into account:
 * All sections include ``DEFAULTSECT`` values as well which means that
   ``.clear()`` on a section may not leave the section visibly empty.  This is
   because default values cannot be deleted from the section (because technically
-  they are not there).  If they are overriden in the section, deleting causes
+  they are not there).  If they are overridden in the section, deleting causes
   the default value to be visible again.  Trying to delete a default value
   causes a ``KeyError``.
 
@@ -399,13 +400,13 @@ However, there are a few differences that should be taken into account:
   * ``parser.popitem()`` never returns it.
 
 * ``parser.get(section, option, **kwargs)`` - the second argument is **not**
-  a fallback value. Note however that the section-level ``get()`` methods are
+  a fallback value.  Note however that the section-level ``get()`` methods are
   compatible both with the mapping protocol and the classic configparser API.
 
 * ``parser.items()`` is compatible with the mapping protocol (returns a list of
   *section_name*, *section_proxy* pairs including the DEFAULTSECT).  However,
   this method can also be invoked with arguments: ``parser.items(section, raw,
-  vars)``. The latter call returns a list of *option*, *value* pairs for
+  vars)``.  The latter call returns a list of *option*, *value* pairs for
   a specified ``section``, with all interpolations expanded (unless
   ``raw=True`` is provided).
 
@@ -539,9 +540,9 @@ the :meth:`__init__` options:
 
 * *delimiters*, default value: ``('=', ':')``
 
-  Delimiters are substrings that delimit keys from values within a section. The
-  first occurrence of a delimiting substring on a line is considered a delimiter.
-  This means values (but not keys) can contain the delimiters.
+  Delimiters are substrings that delimit keys from values within a section.
+  The first occurrence of a delimiting substring on a line is considered
+  a delimiter.  This means values (but not keys) can contain the delimiters.
 
   See also the *space_around_delimiters* argument to
   :meth:`ConfigParser.write`.
@@ -553,7 +554,7 @@ the :meth:`__init__` options:
   Comment prefixes are strings that indicate the start of a valid comment within
   a config file. *comment_prefixes* are used only on otherwise empty lines
   (optionally indented) whereas *inline_comment_prefixes* can be used after
-  every valid value (e.g.  section names, options and empty lines as well). By
+  every valid value (e.g. section names, options and empty lines as well).  By
   default inline comments are disabled and ``'#'`` and ``';'`` are used as
   prefixes for whole line comments.
 
@@ -563,10 +564,10 @@ the :meth:`__init__` options:
 
   Please note that config parsers don't support escaping of comment prefixes so
   using *inline_comment_prefixes* may prevent users from specifying option
-  values with characters used as comment prefixes. When in doubt, avoid setting
-  *inline_comment_prefixes*. In any circumstances, the only way of storing
-  comment prefix characters at the beginning of a line in multiline values is to
-  interpolate the prefix, for example::
+  values with characters used as comment prefixes.  When in doubt, avoid
+  setting *inline_comment_prefixes*.  In any circumstances, the only way of
+  storing comment prefix characters at the beginning of a line in multiline
+  values is to interpolate the prefix, for example::
 
     >>> from configparser import ConfigParser, ExtendedInterpolation
     >>> parser = ConfigParser(interpolation=ExtendedInterpolation())
@@ -611,7 +612,7 @@ the :meth:`__init__` options:
 
   When set to ``True``, the parser will not allow for any section or option
   duplicates while reading from a single source (using :meth:`read_file`,
-  :meth:`read_string` or :meth:`read_dict`). It is recommended to use strict
+  :meth:`read_string` or :meth:`read_dict`).  It is recommended to use strict
   parsers in new applications.
 
   .. versionchanged:: 3.2
@@ -646,12 +647,12 @@ the :meth:`__init__` options:
 
   The convention of allowing a special section of default values for other
   sections or interpolation purposes is a powerful concept of this library,
-  letting users create complex declarative configurations. This section is
+  letting users create complex declarative configurations.  This section is
   normally called ``"DEFAULT"`` but this can be customized to point to any
-  other valid section name. Some typical values include: ``"general"`` or
-  ``"common"``. The name provided is used for recognizing default sections when
-  reading from any source and is used when writing configuration back to
-  a file. Its current value can be retrieved using the
+  other valid section name.  Some typical values include: ``"general"`` or
+  ``"common"``.  The name provided is used for recognizing default sections
+  when reading from any source and is used when writing configuration back to
+  a file.  Its current value can be retrieved using the
   ``parser_instance.default_section`` attribute and may be modified at runtime
   (i.e. to convert files from one format to another).
 
@@ -660,14 +661,30 @@ the :meth:`__init__` options:
   Interpolation behaviour may be customized by providing a custom handler
   through the *interpolation* argument. ``None`` can be used to turn off
   interpolation completely, ``ExtendedInterpolation()`` provides a more
-  advanced variant inspired by ``zc.buildout``. More on the subject in the
+  advanced variant inspired by ``zc.buildout``.  More on the subject in the
   `dedicated documentation section <#interpolation-of-values>`_.
   :class:`RawConfigParser` has a default value of ``None``.
 
+* *converters*, default value: not set
+
+  Config parsers provide option value getters that perform type conversion.  By
+  default :meth:`getint`, :meth:`getfloat`, and :meth:`getboolean` are
+  implemented.  Should other getters be desirable, users may define them in
+  a subclass or pass a dictionary where each key is a name of the converter and
+  each value is a callable implementing said conversion.  For instance, passing
+  ``{'decimal': decimal.Decimal}`` would add :meth:`getdecimal` on both the
+  parser object and all section proxies.  In other words, it will be possible
+  to write both ``parser_instance.getdecimal('section', 'key', fallback=0)``
+  and ``parser_instance['section'].getdecimal('key', 0)``.
+
+  If the converter needs to access the state of the parser, it can be
+  implemented as a method on a config parser subclass.  If the name of this
+  method starts with ``get``, it will be available on all section proxies, in
+  the dict-compatible form (see the ``getdecimal()`` example above).
 
 More advanced customization may be achieved by overriding default values of
-these parser attributes.  The defaults are defined on the classes, so they
-may be overriden by subclasses or by attribute assignment.
+these parser attributes.  The defaults are defined on the classes, so they may
+be overridden by subclasses or by attribute assignment.
 
 .. attribute:: BOOLEAN_STATES
 
@@ -725,10 +742,11 @@ may be overriden by subclasses or by attribute assignment.
 
 .. attribute:: SECTCRE
 
-  A compiled regular expression used to parse section headers. The default
-  matches ``[section]`` to the name ``"section"``. Whitespace is considered part
-  of the section name, thus ``[  larch  ]`` will be read as a section of name
-  ``"  larch  "``. Override this attribute if that's unsuitable.  For example:
+  A compiled regular expression used to parse section headers.  The default
+  matches ``[section]`` to the name ``"section"``.  Whitespace is considered
+  part of the section name, thus ``[  larch  ]`` will be read as a section of
+  name ``"  larch  "``.  Override this attribute if that's unsuitable.  For
+  example:
 
   .. doctest::
 
@@ -859,7 +877,7 @@ interpolation if an option used is not defined elsewhere. ::
 ConfigParser Objects
 --------------------
 
-.. class:: ConfigParser(defaults=None, dict_type=collections.OrderedDict, allow_no_value=False, delimiters=('=', ':'), comment_prefixes=('#', ';'), inline_comment_prefixes=None, strict=True, empty_lines_in_values=True, default_section=configparser.DEFAULTSECT, interpolation=BasicInterpolation())
+.. class:: ConfigParser(defaults=None, dict_type=collections.OrderedDict, allow_no_value=False, delimiters=('=', ':'), comment_prefixes=('#', ';'), inline_comment_prefixes=None, strict=True, empty_lines_in_values=True, default_section=configparser.DEFAULTSECT, interpolation=BasicInterpolation(), converters={})
 
    The main configuration parser.  When *defaults* is given, it is initialized
    into the dictionary of intrinsic defaults.  When *dict_type* is given, it
@@ -869,8 +887,8 @@ ConfigParser Objects
    When *delimiters* is given, it is used as the set of substrings that
    divide keys from values.  When *comment_prefixes* is given, it will be used
    as the set of substrings that prefix comments in otherwise empty lines.
-   Comments can be indented. When *inline_comment_prefixes* is given, it will be
-   used as the set of substrings that prefix comments in non-empty lines.
+   Comments can be indented.  When *inline_comment_prefixes* is given, it will
+   be used as the set of substrings that prefix comments in non-empty lines.
 
    When *strict* is ``True`` (the default), the parser won't allow for
    any section or option duplicates while reading from a single source (file,
@@ -884,13 +902,13 @@ ConfigParser Objects
 
    When *default_section* is given, it specifies the name for the special
    section holding default values for other sections and interpolation purposes
-   (normally named ``"DEFAULT"``). This value can be retrieved and changed on
+   (normally named ``"DEFAULT"``).  This value can be retrieved and changed on
    runtime using the ``default_section`` instance attribute.
 
    Interpolation behaviour may be customized by providing a custom handler
    through the *interpolation* argument. ``None`` can be used to turn off
    interpolation completely, ``ExtendedInterpolation()`` provides a more
-   advanced variant inspired by ``zc.buildout``. More on the subject in the
+   advanced variant inspired by ``zc.buildout``.  More on the subject in the
    `dedicated documentation section <#interpolation-of-values>`_.
 
    All option names used in interpolation will be passed through the
@@ -899,6 +917,12 @@ ConfigParser Objects
    converts option names to lower case), the values ``foo %(bar)s`` and ``foo
    %(BAR)s`` are equivalent.
 
+   When *converters* is given, it should be a dictionary where each key
+   represents the name of a type converter and each value is a callable
+   implementing the conversion from string to the desired datatype.  Every
+   converter gets its own corresponding :meth:`get*()` method on the parser
+   object and section proxies.
+
    .. versionchanged:: 3.1
       The default *dict_type* is :class:`collections.OrderedDict`.
 
@@ -907,6 +931,9 @@ ConfigParser Objects
       *empty_lines_in_values*, *default_section* and *interpolation* were
       added.
 
+   .. versionchanged:: 3.5
+      The *converters* argument was added.
+
 
    .. method:: defaults()
 
@@ -944,7 +971,7 @@ ConfigParser Objects
    .. method:: has_option(section, option)
 
       If the given *section* exists, and contains the given *option*, return
-      :const:`True`; otherwise return :const:`False`. If the specified
+      :const:`True`; otherwise return :const:`False`.  If the specified
       *section* is :const:`None` or an empty string, DEFAULT is assumed.
 
 
@@ -1069,7 +1096,7 @@ ConfigParser Objects
       :meth:`get` method.
 
       .. versionchanged:: 3.2
-         Items present in *vars* no longer appear in the result. The previous
+         Items present in *vars* no longer appear in the result.  The previous
          behaviour mixed actual parser options with variables provided for
          interpolation.
 
@@ -1170,7 +1197,7 @@ RawConfigParser Objects
 
    .. note::
       Consider using :class:`ConfigParser` instead which checks types of
-      the values to be stored internally. If you don't want interpolation, you
+      the values to be stored internally.  If you don't want interpolation, you
       can use ``ConfigParser(interpolation=None)``.
 
 
@@ -1181,7 +1208,7 @@ RawConfigParser Objects
       *default section* name is passed, :exc:`ValueError` is raised.
 
       Type of *section* is not checked which lets users create non-string named
-      sections. This behaviour is unsupported and may cause internal errors.
+      sections.  This behaviour is unsupported and may cause internal errors.
 
 
    .. method:: set(section, option, value)
@@ -1282,3 +1309,4 @@ Exceptions
 .. [1] Config parsers allow for heavy customization.  If you are interested in
        changing the behaviour outlined by the footnote reference, consult the
        `Customizing Parser Behaviour`_ section.
+
diff --git a/Doc/library/constants.rst b/Doc/library/constants.rst
index 42b5af2..d5a0f09 100644
--- a/Doc/library/constants.rst
+++ b/Doc/library/constants.rst
@@ -45,7 +45,6 @@ A small number of constants live in the built-in namespace.  They are:
    for more details.
 
 
-
 .. data:: Ellipsis
 
    The same as ``...``.  Special value used mostly in conjunction with extended
diff --git a/Doc/library/contextlib.rst b/Doc/library/contextlib.rst
index 6f36864..550b347 100644
--- a/Doc/library/contextlib.rst
+++ b/Doc/library/contextlib.rst
@@ -172,6 +172,16 @@ Functions and classes provided:
    .. versionadded:: 3.4
 
 
+.. function:: redirect_stderr(new_target)
+
+   Similar to :func:`~contextlib.redirect_stdout` but redirecting
+   :data:`sys.stderr` to another file or file-like object.
+
+   This context manager is :ref:`reentrant <reentrant-cms>`.
+
+   .. versionadded:: 3.5
+
+
 .. class:: ContextDecorator()
 
    A base class that enables a context manager to also be used as a decorator.
diff --git a/Doc/library/csv.rst b/Doc/library/csv.rst
index 9f7b58a..325a421 100644
--- a/Doc/library/csv.rst
+++ b/Doc/library/csv.rst
@@ -5,6 +5,7 @@
    :synopsis: Write and read tabular data to and from delimited files.
 .. sectionauthor:: Skip Montanaro <skip@pobox.com>
 
+**Source code:** :source:`Lib/csv.py`
 
 .. index::
    single: csv
@@ -418,7 +419,7 @@ 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
+an iterable 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
@@ -430,6 +431,8 @@ read CSV files (assuming they support complex numbers at all).
    Write the *row* parameter to the writer's file object, formatted according to
    the current dialect.
 
+   .. versionchanged:: 3.5
+      Added support of arbitrary iterables.
 
 .. method:: csvwriter.writerows(rows)
 
diff --git a/Doc/library/curses.rst b/Doc/library/curses.rst
index f3e60b4..e8dfd83 100644
--- a/Doc/library/curses.rst
+++ b/Doc/library/curses.rst
@@ -599,6 +599,13 @@ The module :mod:`curses` defines the following functions:
       Only one *ch* can be pushed before :meth:`getch` is called.
 
 
+.. function:: update_lines_cols()
+
+   Update :envvar:`LINES` and :envvar:`COLS`. Useful for detecting manual screen resize.
+
+   .. versionadded:: 3.5
+
+
 .. function:: unget_wch(ch)
 
    Push *ch* so the next :meth:`get_wch` will return it.
diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
index 7dd8613..f82f425 100644
--- a/Doc/library/datetime.rst
+++ b/Doc/library/datetime.rst
@@ -7,6 +7,8 @@
 .. sectionauthor:: Tim Peters <tim@zope.com>
 .. sectionauthor:: A.M. Kuchling <amk@amk.ca>
 
+**Source code:** :source:`Lib/datetime.py`
+
 .. XXX what order should the types be discussed in?
 
 The :mod:`datetime` module supplies classes for manipulating dates and times in
@@ -757,13 +759,19 @@ Other constructors, all class methods:
    :attr:`tzinfo` ``None``. This may raise :exc:`OverflowError`, if the timestamp is
    out of the range of values supported by the platform C :c:func:`gmtime` function,
    and :exc:`OSError` on :c:func:`gmtime` failure.
-   It's common for this to be restricted to years in 1970 through 2038. See also
-   :meth:`fromtimestamp`.
+   It's common for this to be restricted to years in 1970 through 2038.
+
+   To get an aware :class:`.datetime` object, call :meth:`fromtimestamp`::
+
+     datetime.fromtimestamp(timestamp, timezone.utc)
+
+   On the POSIX compliant platforms, it is equivalent to the following
+   expression::
 
-   On the POSIX compliant platforms, ``utcfromtimestamp(timestamp)``
-   is equivalent to the following expression::
+     datetime(1970, 1, 1, tzinfo=timezone.utc) + timedelta(seconds=timestamp)
 
-     datetime(1970, 1, 1) + timedelta(seconds=timestamp)
+   except the latter formula always supports the full years range: between
+   :const:`MINYEAR` and :const:`MAXYEAR` inclusive.
 
    .. versionchanged:: 3.3
       Raise :exc:`OverflowError` instead of :exc:`ValueError` if the timestamp
@@ -1376,10 +1384,13 @@ Supported operations:
 
 * 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.
+In boolean contexts, a :class:`.time` object is always considered to be true.
 
+.. versionchanged:: 3.5
+   Before Python 3.5, a :class:`.time` object was considered to be false if it
+   represented midnight in UTC.  This behavior was considered obscure and
+   error-prone and has been removed in Python 3.5.  See :issue:`13936` for full
+   details.
 
 Instance methods:
 
diff --git a/Doc/library/dbm.rst b/Doc/library/dbm.rst
index e6a82d6..3f3c43d 100644
--- a/Doc/library/dbm.rst
+++ b/Doc/library/dbm.rst
@@ -325,13 +325,18 @@ The module defines the following:
    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 *flag* argument supports only the semantics of ``'c'``
+   and ``'n'`` values.  Other values will default to database being 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 ``0o666`` (and will be modified
    by the prevailing umask).
 
+   .. versionchanged:: 3.5
+      :func:`.open` always creates a new database when the flag has the value
+      ``'n'``.
+
    In addition to the methods provided by the
    :class:`collections.abc.MutableMapping` class, :class:`dumbdbm` objects
    provide the following methods:
diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst
index 759be70..5d7ffff 100644
--- a/Doc/library/decimal.rst
+++ b/Doc/library/decimal.rst
@@ -12,6 +12,8 @@
 .. moduleauthor:: Stefan Krah <skrah at bytereef.org>
 .. sectionauthor:: Raymond D. Hettinger <python at rcn.com>
 
+**Source code:** :source:`Lib/decimal.py`
+
 .. import modules for testing inline doctests with the Sphinx doctest builder
 .. testsetup:: *
 
@@ -742,7 +744,7 @@ Decimal objects
       * ``"NaN"``, indicating that the operand is a quiet NaN (Not a Number).
       * ``"sNaN"``, indicating that the operand is a signaling NaN.
 
-   .. method:: quantize(exp, rounding=None, context=None, watchexp=True)
+   .. method:: quantize(exp, rounding=None, context=None)
 
       Return a value equal to the first operand after rounding and having the
       exponent of the second operand.
@@ -765,14 +767,8 @@ Decimal objects
       ``context`` argument; if neither argument is given the rounding mode of
       the current thread's context is used.
 
-      If *watchexp* is set (default), then an error is returned whenever the
-      resulting exponent is greater than :attr:`Emax` or less than
-      :attr:`Etiny`.
-
-      .. deprecated:: 3.3
-         *watchexp* is an implementation detail from the pure Python version
-         and is not present in the C version. It will be removed in version
-         3.4, where it defaults to ``True``.
+      An error is returned whenever the resulting exponent is greater than
+      :attr:`Emax` or less than :attr:`Etiny`.
 
    .. method:: radix()
 
@@ -2092,4 +2088,3 @@ Alternatively, inputs can be rounded upon creation using the
 
    >>> Context(prec=5, rounding=ROUND_DOWN).create_decimal('1.2345678')
    Decimal('1.2345')
-
diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst
index 5f72ea6..efaac7a 100644
--- a/Doc/library/difflib.rst
+++ b/Doc/library/difflib.rst
@@ -7,6 +7,8 @@
 .. sectionauthor:: Tim Peters <tim_one@users.sourceforge.net>
 .. Markup by Fred L. Drake, Jr. <fdrake@acm.org>
 
+**Source code:** :source:`Lib/difflib.py`
+
 .. testsetup::
 
    import sys
@@ -25,7 +27,9 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
    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
+   elements; these "junk" elements are ones that are uninteresting in some
+   sense, such as blank lines or whitespace.  (Handling junk is an
+   extension to the Ratcliff and Obershelp algorithm.) 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.
@@ -100,7 +104,8 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
 
    The following methods are public:
 
-   .. method:: make_file(fromlines, tolines, fromdesc='', todesc='', context=False, numlines=5)
+   .. method:: make_file(fromlines, tolines, fromdesc='', todesc='', context=False, \
+                         numlines=5, *, charset='utf-8')
 
       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
@@ -119,6 +124,10 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
       the next difference highlight at the top of the browser without any leading
       context).
 
+      .. versionchanged:: 3.5
+         *charset* keyword-only argument was added.  The default charset of
+         HTML document changed from ``'ISO-8859-1'`` to ``'utf-8'``.
+
    .. method:: make_table(fromlines, tolines, fromdesc='', todesc='', context=False, numlines=5)
 
       Compares *fromlines* and *tolines* (lists of strings) and returns a string which
@@ -208,7 +217,7 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
    Compare *a* and *b* (lists of strings); return a :class:`Differ`\ -style
    delta (a :term:`generator` generating the delta lines).
 
-   Optional keyword parameters *linejunk* and *charjunk* are for filter functions
+   Optional keyword parameters *linejunk* and *charjunk* are filtering functions
    (or ``None``):
 
    *linejunk*: A function that accepts a single string argument, and returns
@@ -222,7 +231,7 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
    *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!).
+   blank or tab; it's a bad idea to include newline in this!).
 
    :file:`Tools/scripts/ndiff.py` is a command-line front-end to this function.
 
@@ -306,6 +315,21 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module.
 
    See :ref:`difflib-interface` for a more detailed example.
 
+.. function:: diff_bytes(dfunc, a, b, fromfile=b'', tofile=b'', fromfiledate=b'', tofiledate=b'', n=3, lineterm=b'\\n')
+
+   Compare *a* and *b* (lists of bytes objects) using *dfunc*; yield a
+   sequence of delta lines (also bytes) in the format returned by *dfunc*.
+   *dfunc* must be a callable, typically either :func:`unified_diff` or
+   :func:`context_diff`.
+
+   Allows you to compare data with unknown or inconsistent encoding. All
+   inputs except *n* must be bytes objects, not str. Works by losslessly
+   converting all inputs (except *n*) to str, and calling ``dfunc(a, b,
+   fromfile, tofile, fromfiledate, tofiledate, n, lineterm)``. The output of
+   *dfunc* is then converted back to bytes, so the delta lines that you
+   receive have the same unknown/inconsistent encodings as *a* and *b*.
+
+   .. versionadded:: 3.5
 
 .. function:: IS_LINE_JUNK(line)
 
@@ -622,6 +646,12 @@ The :class:`Differ` class has this constructor:
    length 1), and returns true if the character is junk. The default is ``None``,
    meaning that no character is considered junk.
 
+   These junk-filtering functions speed up matching to find
+   differences and do not cause any differing lines or characters to
+   be ignored.  Read the description of the
+   :meth:`~SequenceMatcher.find_longest_match` method's *isjunk*
+   parameter for an explanation.
+
    :class:`Differ` objects are used (deltas generated) via a single method:
 
 
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
index b816dcc..b00d619 100644
--- a/Doc/library/dis.rst
+++ b/Doc/library/dis.rst
@@ -48,8 +48,9 @@ code.
 
 .. class:: Bytecode(x, *, first_line=None, current_offset=None)
 
-   Analyse the bytecode corresponding to a function, method, string of source
-   code, or a code object (as returned by :func:`compile`).
+
+   Analyse the bytecode corresponding to a function, generator, method, string
+   of source code, or a code object (as returned by :func:`compile`).
 
    This is a convenience wrapper around many of the functions listed below, most
    notably :func:`get_instructions`, as iterating over a :class:`Bytecode`
@@ -109,7 +110,7 @@ operation is being performed, so the intermediate analysis object isn't useful:
 .. function:: code_info(x)
 
    Return a formatted multi-line string with detailed code object information
-   for the supplied function, method, source code string or code object.
+   for the supplied function, generator, method, source code string or code object.
 
    Note that the exact contents of code info strings are highly implementation
    dependent and they may change arbitrarily across Python VMs or Python
@@ -136,11 +137,11 @@ operation is being performed, so the intermediate analysis object isn't useful:
 .. function:: dis(x=None, *, file=None)
 
    Disassemble the *x* object.  *x* can denote either a module, a class, a
-   method, a function, a code object, a string of source code or a byte sequence
-   of raw bytecode.  For a module, it disassembles all functions.  For a class,
-   it disassembles all methods.  For a code object or sequence of raw bytecode,
-   it prints one line per bytecode instruction.  Strings are first compiled to
-   code objects with the :func:`compile` built-in function before being
+   method, a function, a generator, a code object, a string of source code or
+   a byte sequence of raw bytecode.  For a module, it disassembles all functions.
+   For a class, it disassembles all methods.  For a code object or sequence of
+   raw bytecode, it prints one line per bytecode instruction.  Strings are first
+   compiled to code objects with the :func:`compile` built-in function before being
    disassembled.  If no object is provided, this function disassembles the last
    traceback.
 
@@ -361,6 +362,13 @@ result back on the stack.
    Implements ``TOS = TOS1 * TOS``.
 
 
+.. opcode:: BINARY_MATRIX_MULTIPLY
+
+   Implements ``TOS = TOS1 @ TOS``.
+
+   .. versionadded:: 3.5
+
+
 .. opcode:: BINARY_FLOOR_DIVIDE
 
    Implements ``TOS = TOS1 // TOS``.
@@ -433,6 +441,13 @@ the original TOS1.
    Implements in-place ``TOS = TOS1 * TOS``.
 
 
+.. opcode:: INPLACE_MATRIX_MULTIPLY
+
+   Implements in-place ``TOS = TOS1 @ TOS``.
+
+   .. versionadded:: 3.5
+
+
 .. opcode:: INPLACE_FLOOR_DIVIDE
 
    Implements in-place ``TOS = TOS1 // TOS``.
diff --git a/Doc/library/distribution.rst b/Doc/library/distribution.rst
index c4954d1..3e6e84b 100644
--- a/Doc/library/distribution.rst
+++ b/Doc/library/distribution.rst
@@ -12,3 +12,4 @@ with a local index server, or without any index server at all.
    distutils.rst
    ensurepip.rst
    venv.rst
+   zipapp.rst
diff --git a/Doc/library/doctest.rst b/Doc/library/doctest.rst
index 2e372de..9aa9ea6 100644
--- a/Doc/library/doctest.rst
+++ b/Doc/library/doctest.rst
@@ -1058,15 +1058,9 @@ from text files and modules with doctests:
 
    This function uses the same search technique as :func:`testmod`.
 
-   .. note::
-      Unlike :func:`testmod` and :class:`DocTestFinder`, this function raises
-      a :exc:`ValueError` if *module* contains no docstrings.  You can prevent
-      this error by passing a :class:`DocTestFinder` instance as the
-      *test_finder* argument with its *exclude_empty* keyword argument set
-      to ``False``::
-
-         >>> finder = doctest.DocTestFinder(exclude_empty=False)
-         >>> suite = doctest.DocTestSuite(test_finder=finder)
+   .. versionchanged:: 3.5
+      :func:`DocTestSuite` returns an empty :class:`unittest.TestSuite` if *module*
+      contains no docstrings instead of raising :exc:`ValueError`.
 
 
 Under the covers, :func:`DocTestSuite` creates a :class:`unittest.TestSuite` out
diff --git a/Doc/library/email.mime.rst b/Doc/library/email.mime.rst
index 1d70225..67d0a67 100644
--- a/Doc/library/email.mime.rst
+++ b/Doc/library/email.mime.rst
@@ -195,7 +195,8 @@ Here are the classes:
    set of the text and is passed as an argument to the
    :class:`~email.mime.nonmultipart.MIMENonMultipart` constructor; it defaults
    to ``us-ascii`` if the string contains only ``ascii`` code points, and
-   ``utf-8`` otherwise.
+   ``utf-8`` otherwise.  The *_charset* parameter accepts either a string or a
+   :class:`~email.charset.Charset` instance.
 
    Unless the *_charset* argument is explicitly set to ``None``, the
    MIMEText object created will have both a :mailheader:`Content-Type` header
@@ -206,3 +207,6 @@ Here are the classes:
    ``Content-Transfer-Encoding`` header, after which a ``set_payload`` call
    will automatically encode the new payload (and add a new
    :mailheader:`Content-Transfer-Encoding` header).
+
+   .. versionchanged:: 3.5
+      *_charset* also accepts :class:`~email.charset.Charset` instances.
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index cf09559..d3b838c 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -314,11 +314,11 @@ Then::
     >>> str(Mood.funky)
     'my custom str! 1'
 
-The rules for what is allowed are as follows: _sunder_ names (starting and
-ending with a single underscore) are reserved by enum and cannot be used;
-all other attributes defined within an enumeration will become members of this
-enumeration, with the exception of *__dunder__* names and descriptors (methods
-are also descriptors).
+The rules for what is allowed are as follows: names that start and end with a
+with a single underscore are reserved by enum and cannot be used; all other
+attributes defined within an enumeration will become members of this
+enumeration, with the exception of special methods (:meth:`__str__`,
+:meth:`__add__`, etc.) and descriptors (methods are also descriptors).
 
 Note:  if your enumeration defines :meth:`__new__` and/or :meth:`__init__` then
 whatever value(s) were given to the enum member will be passed into those
@@ -400,7 +400,8 @@ The second argument is the *source* of enumeration member names.  It can be a
 whitespace-separated string of names, a sequence of names, a sequence of
 2-tuples with key/value pairs, or a mapping (e.g. dictionary) of names to
 values.  The last two options enable assigning arbitrary values to
-enumerations; the others auto-assign increasing integers starting with 1.  A
+enumerations; the others auto-assign increasing integers starting with 1 (use
+the ``start`` parameter to specify a different starting value).  A
 new class derived from :class:`Enum` is returned.  In other words, the above
 assignment to :class:`Animal` is equivalent to::
 
@@ -438,12 +439,12 @@ SomeData in the global scope::
 
 The complete signature is::
 
-    Enum(value='NewEnumName', names=<...>, *, module='...', qualname='...', type=<mixed-in class>)
+    Enum(value='NewEnumName', names=<...>, *, module='...', qualname='...', type=<mixed-in class>, start=1)
 
 :value: What the new Enum class will record as its name.
 
 :names: The Enum members.  This can be a whitespace or comma separated string
-  (values will start at 1)::
+  (values will start at 1 unless otherwise specified)::
 
     'red green blue' | 'red,green,blue' | 'red, green, blue'
 
@@ -465,6 +466,11 @@ The complete signature is::
 
 :type: type to mix in to new Enum class.
 
+:start: number to start counting at if only names are passed in
+
+.. versionchanged:: 3.5
+   The *start* parameter was added.
+
 
 Derived Enumerations
 --------------------
diff --git a/Doc/library/errno.rst b/Doc/library/errno.rst
index d2163b6..22a5cbc 100644
--- a/Doc/library/errno.rst
+++ b/Doc/library/errno.rst
@@ -41,7 +41,10 @@ defined by the module.  The specific list of defined symbols is available as
 
 .. data:: EINTR
 
-   Interrupted system call
+   Interrupted system call.
+
+   .. seealso::
+      This error is mapped to the exception :exc:`InterruptedError`.
 
 
 .. data:: EIO
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
index 271a5c8..bddd0ed 100644
--- a/Doc/library/exceptions.rst
+++ b/Doc/library/exceptions.rst
@@ -536,7 +536,12 @@ depending on the system error code.
 .. exception:: InterruptedError
 
    Raised when a system call is interrupted by an incoming signal.
-   Corresponds to :c:data:`errno` ``EINTR``.
+   Corresponds to :c:data:`errno` :py:data:`~errno.EINTR`.
+
+   .. versionchanged:: 3.5
+      Python now retries system calls when a syscall is interrupted by a
+      signal, except if the signal handler raises an exception (see :pep:`475`
+      for the rationale), instead of raising :exc:`InterruptedError`.
 
 .. exception:: IsADirectoryError
 
diff --git a/Doc/library/faulthandler.rst b/Doc/library/faulthandler.rst
index eb2016a..3a5badd 100644
--- a/Doc/library/faulthandler.rst
+++ b/Doc/library/faulthandler.rst
@@ -47,6 +47,9 @@ Dumping the traceback
    Dump the tracebacks of all threads into *file*. If *all_threads* is
    ``False``, dump only the current thread.
 
+   .. versionchanged:: 3.5
+      Added support for passing file descriptor to this function.
+
 
 Fault handler state
 -------------------
@@ -59,6 +62,12 @@ Fault handler state
    produce tracebacks for every running thread. Otherwise, dump only the current
    thread.
 
+   The *file* must be kept open until the fault handler is disabled: see
+   :ref:`issue with file descriptors <faulthandler-fd>`.
+
+   .. versionchanged:: 3.5
+      Added support for passing file descriptor to this function.
+
 .. function:: disable()
 
    Disable the fault handler: uninstall the signal handlers installed by
@@ -82,9 +91,16 @@ Dumping the tracebacks after a timeout
    call replaces previous parameters and resets the timeout. The timer has a
    sub-second resolution.
 
+   The *file* must be kept open until the traceback is dumped or
+   :func:`cancel_dump_traceback_later` is called: see :ref:`issue with file
+   descriptors <faulthandler-fd>`.
+
    This function is implemented using a watchdog thread and therefore is not
    available if Python is compiled with threads disabled.
 
+   .. versionchanged:: 3.5
+      Added support for passing file descriptor to this function.
+
 .. function:: cancel_dump_traceback_later()
 
    Cancel the last call to :func:`dump_traceback_later`.
@@ -99,8 +115,14 @@ Dumping the traceback on a user signal
    the traceback of all threads, or of the current thread if *all_threads* is
    ``False``, into *file*. Call the previous handler if chain is ``True``.
 
+   The *file* must be kept open until the signal is unregistered by
+   :func:`unregister`: see :ref:`issue with file descriptors <faulthandler-fd>`.
+
    Not available on Windows.
 
+   .. versionchanged:: 3.5
+      Added support for passing file descriptor to this function.
+
 .. function:: unregister(signum)
 
    Unregister a user signal: uninstall the handler of the *signum* signal
@@ -110,6 +132,8 @@ Dumping the traceback on a user signal
    Not available on Windows.
 
 
+.. _faulthandler-fd:
+
 Issue with file descriptors
 ---------------------------
 
diff --git a/Doc/library/fcntl.rst b/Doc/library/fcntl.rst
index 8e932fb..432140f 100644
--- a/Doc/library/fcntl.rst
+++ b/Doc/library/fcntl.rst
@@ -28,41 +28,41 @@ descriptor.
 The module defines the following functions:
 
 
-.. function:: fcntl(fd, op[, arg])
+.. function:: fcntl(fd, cmd, arg=0)
 
-   Perform the operation *op* on file descriptor *fd* (file objects providing
+   Perform the operation *cmd* on file descriptor *fd* (file objects providing
    a :meth:`~io.IOBase.fileno` method are accepted as well).  The values used
-   for *op* are operating system dependent, and are available as constants
+   for *cmd* are operating system dependent, and are available as constants
    in the :mod:`fcntl` module, using the same names as used in the relevant C
-   header files.  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 :c:func:`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
-   :c:func:`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.
+   header files. The argument *arg* can either be an integer value, or a
+   :class:`bytes` object. With an integer value, the return value of this
+   function is the integer return value of the C :c:func:`fcntl` call.  When
+   the argument is bytes 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 :c:func:`fcntl` call.  The return value after a successful
+   call is the contents of the buffer, converted to a :class:`bytes` object.
+   The length of the returned object 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 :c:func:`fcntl` fails, an :exc:`OSError` is raised.
 
 
-.. function:: ioctl(fd, op[, arg[, mutate_flag]])
+.. function:: ioctl(fd, request, arg=0, mutate_flag=True)
 
    This function is identical to the :func:`~fcntl.fcntl` function, except
    that the argument handling is even more complicated.
 
-   The op parameter is limited to values that can fit in 32-bits.
-   Additional constants of interest for use as the *op* argument can be
+   The *request* parameter is limited to values that can fit in 32-bits.
+   Additional constants of interest for use as the *request* argument can be
    found in the :mod:`termios` module, under the same names as used in
    the relevant C header files.
 
-   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.
+   The parameter *arg* can be one of an integer, an object supporting the
+   read-only buffer interface (like :class:`bytes`) or an object supporting
+   the read-write buffer interface (like :class:`bytearray`).
 
    In all but the last case, behaviour is as for the :func:`~fcntl.fcntl`
    function.
@@ -72,7 +72,7 @@ The module defines the following functions:
 
    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
+   so long as the buffer you pass is at least as long as what the operating system
    wants to put there, things should work.
 
    If *mutate_flag* is true (the default), then the buffer is (in effect) passed
@@ -97,25 +97,25 @@ The module defines the following functions:
       array('h', [13341])
 
 
-.. function:: flock(fd, op)
+.. function:: flock(fd, operation)
 
-   Perform the lock operation *op* on file descriptor *fd* (file objects providing
+   Perform the lock operation *operation* on file descriptor *fd* (file objects providing
    a :meth:`~io.IOBase.fileno` method are accepted as well). See the Unix manual
    :manpage:`flock(2)` for details.  (On some systems, this function is emulated
    using :c:func:`fcntl`.)
 
 
-.. function:: lockf(fd, operation, [length, [start, [whence]]])
+.. function:: lockf(fd, cmd, len=0, start=0, whence=0)
 
    This is essentially a wrapper around the :func:`~fcntl.fcntl` locking calls.
-   *fd* is the file descriptor of the file to lock or unlock, and *operation*
+   *fd* is the file descriptor of the file to lock or unlock, and *cmd*
    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
+   When *cmd* is :const:`LOCK_SH` or :const:`LOCK_EX`, it can also be
    bitwise ORed with :const:`LOCK_NB` to avoid blocking on lock acquisition.
    If :const:`LOCK_NB` is used and the lock cannot be acquired, an
    :exc:`OSError` will be raised and the exception will have an *errno*
@@ -124,7 +124,7 @@ The module defines the following functions:
    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
+   *len* 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:`io.IOBase.seek`, specifically:
 
@@ -133,7 +133,7 @@ The module defines the following functions:
    * :const:`2` -- relative to the end of the file (:data:`os.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
+   The default for *len* 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)::
@@ -147,9 +147,9 @@ Examples (all on a SVR4 compliant system)::
    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.
+integer value; in the second example it will hold a :class:`bytes` object.  The
+structure lay-out for the *lockdata* variable is system dependent --- therefore
+using the :func:`flock` call may be better.
 
 
 .. seealso::
diff --git a/Doc/library/formatter.rst b/Doc/library/formatter.rst
index 1847a80..a515f74 100644
--- a/Doc/library/formatter.rst
+++ b/Doc/library/formatter.rst
@@ -5,7 +5,7 @@
    :synopsis: Generic output formatter and device interface.
    :deprecated:
 
-.. deprecated:: 3.4
+.. deprecated-removed:: 3.4 3.6
    Due to lack of usage, the formatter module has been deprecated and is slated
    for removal in Python 3.6.
 
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index d9e5cfb..e982ceb 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -156,11 +156,12 @@ are always available.  They are listed here in alphabetical order.
 
 .. function:: chr(i)
 
-   Return the string representing a character whose Unicode code point 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 is from 0 through
-   1,114,111 (0x10FFFF in base 16).  :exc:`ValueError` will be raised if *i* is
-   outside that range.
+   Return the string representing a character whose Unicode code point is the
+   integer *i*.  For example, ``chr(97)`` returns the string ``'a'``, while
+   ``chr(957)`` returns the string ``'ν'``. This is the inverse of :func:`ord`.
+
+   The valid range for the argument is from 0 through 1,114,111 (0x10FFFF in
+   base 16).  :exc:`ValueError` will be raised if *i* is outside that range.
 
 
 .. function:: classmethod(function)
@@ -972,9 +973,11 @@ are always available.  They are listed here in alphabetical order.
      Characters not supported by the encoding are replaced with the
      appropriate XML character reference ``&#nnn;``.
 
-   * ``'backslashreplace'`` (also only supported when writing)
-     replaces unsupported characters with Python's backslashed escape
-     sequences.
+   * ``'backslashreplace'`` replaces malformed data by Python's backslashed
+     escape sequences.
+
+   * ``'namereplace'`` (also only supported when writing)
+     replaces unsupported characters with ``\N{...}`` escape sequences.
 
    .. index::
       single: universal newlines; open() built-in function
@@ -999,8 +1002,8 @@ are always available.  They are listed here in alphabetical order.
 
    If *closefd* is ``False`` and a file descriptor rather than a filename was
    given, the underlying file descriptor will be kept open when the file is
-   closed.  If a filename is given *closefd* has no effect and must be ``True``
-   (the default).
+   closed.  If a filename is given *closefd* must be ``True`` (the default)
+   otherwise an error will be raised.
 
    A custom opener can be used by passing a callable as *opener*. The underlying
    file descriptor for the file object is then obtained by calling *opener* with
@@ -1062,14 +1065,18 @@ are always available.  They are listed here in alphabetical order.
 
       The ``'U'`` mode.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
-.. XXX works for bytes too, but should it?
 .. function:: ord(c)
 
    Given a string representing one Unicode character, return an integer
-   representing the Unicode code
-   point of that character.  For example, ``ord('a')`` returns the integer ``97``
-   and ``ord('\u2020')`` returns ``8224``.  This is the inverse of :func:`chr`.
+   representing the Unicode code point of that character.  For example,
+   ``ord('a')`` returns the integer ``97`` and ``ord('ν')`` returns ``957``.
+   This is the inverse of :func:`chr`.
 
 
 .. function:: pow(x, y[, z])
@@ -1218,8 +1225,8 @@ are always available.  They are listed here in alphabetical order.
 .. function:: round(number[, ndigits])
 
    Return the floating point value *number* rounded to *ndigits* digits after
-   the decimal point.  If *ndigits* is omitted, it defaults to zero. Delegates
-   to ``number.__round__(ndigits)``.
+   the decimal point.  If *ndigits* is omitted, it returns the nearest integer
+   to its input.  Delegates to ``number.__round__(ndigits)``.
 
    For the built-in types supporting :func:`round`, values are rounded to the
    closest multiple of 10 to the power minus *ndigits*; if two multiples are
diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst
index 8135542..d11c2e1 100644
--- a/Doc/library/gc.rst
+++ b/Doc/library/gc.rst
@@ -186,7 +186,7 @@ values but should not rebind them):
    added to this list rather than freed.
 
    .. versionchanged:: 3.2
-      If this list is non-empty at interpreter shutdown, a
+      If this list is non-empty at :term:`interpreter shutdown`, a
       :exc:`ResourceWarning` is emitted, which is silent by default.  If
       :const:`DEBUG_UNCOLLECTABLE` is set, in addition all uncollectable objects
       are printed.
@@ -252,8 +252,8 @@ The following constants are provided for use with :func:`set_debug`:
    to the ``garbage`` list.
 
    .. versionchanged:: 3.2
-      Also print the contents of the :data:`garbage` list at interpreter
-      shutdown, if it isn't empty.
+      Also print the contents of the :data:`garbage` list at
+      :term:`interpreter shutdown`, if it isn't empty.
 
 .. data:: DEBUG_SAVEALL
 
diff --git a/Doc/library/gettext.rst b/Doc/library/gettext.rst
index ff23b59..514cc5a 100644
--- a/Doc/library/gettext.rst
+++ b/Doc/library/gettext.rst
@@ -344,9 +344,9 @@ will assume message ids as Unicode strings, not byte strings.
 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:`OSError`.
+If the :file:`.mo` file's magic number is invalid, the major version number is
+unexpected, or if other problems occur while reading the file, instantiating a
+:class:`GNUTranslations` class can raise :exc:`OSError`.
 
 The following methods are overridden from the base class implementation:
 
diff --git a/Doc/library/glob.rst b/Doc/library/glob.rst
index abcbf38..50f38a4 100644
--- a/Doc/library/glob.rst
+++ b/Doc/library/glob.rst
@@ -29,7 +29,7 @@ For example, ``'[?]'`` matches the character ``'?'``.
    The :mod:`pathlib` module offers high-level path objects.
 
 
-.. function:: glob(pathname)
+.. function:: glob(pathname, *, recursive=False)
 
    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
@@ -37,8 +37,19 @@ For example, ``'[?]'`` matches the character ``'?'``.
    :file:`../../Tools/\*/\*.gif`), and can contain shell-style wildcards. Broken
    symlinks are included in the results (as in the shell).
 
+   If *recursive* is true, the pattern "``**``" will match any files and zero or
+   more directories and subdirectories.  If the pattern is followed by a
+   ``os.sep``, only directories and subdirectories match.
 
-.. function:: iglob(pathname)
+   .. note::
+      Using the "``**``" pattern in large directory trees may consume
+      an inordinate amount of time.
+
+   .. versionchanged:: 3.5
+      Support for recursive globs using "``**``".
+
+
+.. function:: iglob(pathname, recursive=False)
 
    Return an :term:`iterator` which yields the same values as :func:`glob`
    without actually storing them all simultaneously.
@@ -55,8 +66,9 @@ For example, ``'[?]'`` matches the character ``'?'``.
    .. versionadded:: 3.4
 
 
-For example, consider a directory containing only the following files:
-:file:`1.gif`, :file:`2.txt`, and :file:`card.gif`.  :func:`glob` will produce
+For example, consider a directory containing the following files:
+:file:`1.gif`, :file:`2.txt`, :file:`card.gif` and a subdirectory :file:`sub`
+which contains only the file :file:`3.txt`.  :func:`glob` will produce
 the following results.  Notice how any leading components of the path are
 preserved. ::
 
@@ -67,6 +79,10 @@ preserved. ::
    ['1.gif', 'card.gif']
    >>> glob.glob('?.gif')
    ['1.gif']
+   >>> glob.glob('**/*.txt', recursive=True)
+   ['2.txt', 'sub/3.txt']
+   >>> glob.glob('./**/', recursive=True)
+   ['./', './sub/']
 
 If the directory contains files starting with ``.`` they won't be matched by
 default. For example, consider a directory containing :file:`card.gif` and
diff --git a/Doc/library/gzip.rst b/Doc/library/gzip.rst
index 78536fa..04c41d5 100644
--- a/Doc/library/gzip.rst
+++ b/Doc/library/gzip.rst
@@ -90,13 +90,9 @@ The module defines the following items:
    is no compression. The default is ``9``.
 
    The *mtime* argument is an optional numeric timestamp to be written to
-   the stream when compressing.  All :program:`gzip` compressed streams are
-   required to contain a timestamp.  If omitted or ``None``, the current
-   time is used.  This module ignores the timestamp when decompressing;
-   however, some programs, such as :program:`gunzip`\ , make use of it.
-   The format of the timestamp is the same as that of the return value of
-   ``time.time()`` and of the ``st_mtime`` attribute of the object returned
-   by ``os.stat()``.
+   the last modification time field in the stream when compressing.  It
+   should only be provided in compression mode.  If omitted or ``None``, the
+   current time is used.  See the :attr:`mtime` attribute for more details.
 
    Calling a :class:`GzipFile` object's :meth:`close` method does not close
    *fileobj*, since you might wish to append more material after the compressed
@@ -108,9 +104,9 @@ The module defines the following items:
    including iteration and the :keyword:`with` statement.  Only the
    :meth:`truncate` method isn't implemented.
 
-   :class:`GzipFile` also provides the following method:
+   :class:`GzipFile` also provides the following method and attribute:
 
-   .. method:: peek([n])
+   .. method:: peek(n)
 
       Read *n* uncompressed bytes without advancing the file position.
       At most one single read on the compressed stream is done to satisfy
@@ -124,9 +120,21 @@ The module defines the following items:
 
       .. versionadded:: 3.2
 
+   .. attribute:: mtime
+
+      When decompressing, the value of the last modification time field in
+      the most recently read header may be read from this attribute, as an
+      integer.  The initial value before reading any headers is ``None``.
+
+      All :program:`gzip` compressed streams are required to contain this
+      timestamp field.  Some programs, such as :program:`gunzip`\ , make use
+      of the timestamp.  The format is the same as the return value of
+      :func:`time.time` and the :attr:`~os.stat_result.st_mtime` attribute of
+      the object returned by :func:`os.stat`.
+
    .. versionchanged:: 3.1
       Support for the :keyword:`with` statement was added, along with the
-      *mtime* argument.
+      *mtime* constructor argument and :attr:`mtime` attribute.
 
    .. versionchanged:: 3.2
       Support for zero-padded and unseekable files was added.
@@ -137,6 +145,12 @@ The module defines the following items:
    .. versionchanged:: 3.4
       Added support for the ``'x'`` and ``'xb'`` modes.
 
+   .. versionchanged:: 3.5
+      Added support for writing arbitrary
+      :term:`bytes-like objects <bytes-like object>`.
+      The :meth:`~io.BufferedIOBase.read` method now accepts an argument of
+      ``None``.
+
 
 .. function:: compress(data, compresslevel=9)
 
@@ -175,9 +189,10 @@ Example of how to create a compressed GZIP file::
 Example of how to GZIP compress an existing file::
 
    import gzip
+   import shutil
    with open('/home/joe/file.txt', 'rb') as f_in:
        with gzip.open('/home/joe/file.txt.gz', 'wb') as f_out:
-           f_out.writelines(f_in)
+           shutil.copyfileobj(f_in, f_out)
 
 Example of how to GZIP compress a binary string::
 
diff --git a/Doc/library/heapq.rst b/Doc/library/heapq.rst
index f8970be..9fbbcc6 100644
--- a/Doc/library/heapq.rst
+++ b/Doc/library/heapq.rst
@@ -82,7 +82,7 @@ The following functions are provided:
 The module also offers three general purpose functions based on heaps.
 
 
-.. function:: merge(*iterables)
+.. function:: merge(*iterables, key=None, reverse=False)
 
    Merge multiple sorted inputs into a single sorted output (for example, merge
    timestamped entries from multiple log files).  Returns an :term:`iterator`
@@ -92,6 +92,18 @@ The module also offers three general purpose functions based on heaps.
    not pull the data into memory all at once, and assumes that each of the input
    streams is already sorted (smallest to largest).
 
+   Has two optional arguments which must be specified as keyword arguments.
+
+   *key* specifies a :term:`key function` of one argument that is used to
+   extract a comparison key from each input element.  The default value is
+   ``None`` (compare the elements directly).
+
+   *reverse* is a boolean value.  If set to ``True``, then the input elements
+   are merged as if each comparison were reversed.
+
+   .. versionchanged:: 3.5
+      Added the optional *key* and *reverse* parameters.
+
 
 .. function:: nlargest(n, iterable, key=None)
 
diff --git a/Doc/library/html.parser.rst b/Doc/library/html.parser.rst
index 44b7d6e..b84c60b 100644
--- a/Doc/library/html.parser.rst
+++ b/Doc/library/html.parser.rst
@@ -16,21 +16,13 @@
 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.
 
-.. class:: HTMLParser(strict=False, *, convert_charrefs=False)
+.. class:: HTMLParser(*, convert_charrefs=True)
 
-   Create a parser instance.
+   Create a parser instance able to parse invalid markup.
 
-   If *convert_charrefs* is ``True`` (default: ``False``), all character
+   If *convert_charrefs* is ``True`` (the default), all character
    references (except the ones in ``script``/``style`` elements) are
    automatically converted to the corresponding Unicode characters.
-   The use of ``convert_charrefs=True`` is encouraged and will become
-   the default in Python 3.5.
-
-   If *strict* is ``False`` (the default), the parser will accept and parse
-   invalid markup.  If *strict* is ``True`` the parser will raise an
-   :exc:`~html.parser.HTMLParseError` exception instead [#]_ when it's not
-   able to parse the markup.  The use of ``strict=True`` is discouraged and
-   the *strict* argument is deprecated.
 
    An :class:`.HTMLParser` instance is fed HTML data and calls handler methods
    when start tags, end tags, text, comments, and other markup elements are
@@ -40,31 +32,11 @@ parsing text files formatted in HTML (HyperText Mark-up Language) and XHTML.
    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.
 
-   .. versionchanged:: 3.2
-      *strict* argument added.
-
-   .. deprecated-removed:: 3.3 3.5
-      The *strict* argument and the strict mode have been deprecated.
-      The parser is now able to accept and parse invalid markup too.
-
    .. versionchanged:: 3.4
       *convert_charrefs* keyword argument added.
 
-An exception is defined as well:
-
-
-.. exception:: HTMLParseError
-
-   Exception raised by the :class:`HTMLParser` class when it encounters an error
-   while parsing and *strict* is ``True``.  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.
-
-   .. deprecated-removed:: 3.3 3.5
-      This exception has been deprecated because it's never raised by the parser
-      (when the default non-strict mode is used).
+   .. versionchanged:: 3.5
+      The default value for argument *convert_charrefs* is now ``True``.
 
 
 Example HTML Parser Application
@@ -246,8 +218,7 @@ implementations do nothing (except for :meth:`~HTMLParser.handle_startendtag`):
 
    The *data* parameter will be the entire contents of the declaration inside
    the ``<![...]>`` markup.  It is sometimes useful to be overridden by a
-   derived class.  The base class implementation raises an :exc:`HTMLParseError`
-   when *strict* is ``True``.
+   derived class.  The base class implementation does nothing.
 
 
 .. _htmlparser-examples:
@@ -358,9 +329,3 @@ Parsing invalid HTML (e.g. unquoted attributes) also works::
    Data     : tag soup
    End tag  : p
    End tag  : a
-
-.. rubric:: Footnotes
-
-.. [#] For backward compatibility reasons *strict* mode does not raise
-       exceptions for all non-compliant HTML.  That is, some invalid HTML
-       is tolerated even in *strict* mode.
diff --git a/Doc/library/http.client.rst b/Doc/library/http.client.rst
index 6324305..7d160ce 100644
--- a/Doc/library/http.client.rst
+++ b/Doc/library/http.client.rst
@@ -180,6 +180,17 @@ The following exceptions are raised as appropriate:
    is received in the HTTP protocol from the server.
 
 
+.. exception:: RemoteDisconnected
+
+   A subclass of :exc:`ConnectionResetError` and :exc:`BadStatusLine`.  Raised
+   by :meth:`HTTPConnection.getresponse` when the attempt to read the response
+   results in no data read from the connection, indicating that the remote end
+   has closed the connection.
+
+   .. versionadded:: 3.5
+      Previously, :exc:`BadStatusLine`\ ``('')`` was raised.
+
+
 The constants defined in this module are:
 
 .. data:: HTTP_PORT
@@ -191,221 +202,15 @@ The constants defined in this module are:
 
    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                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.1.1>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`SWITCHING_PROTOCOLS`             | ``101`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.1.2                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.1.2>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`PROCESSING`                      | ``102`` | WEBDAV, `RFC 2518, Section 10.1                                       |
-|                                          |         | <http://www.webdav.org/specs/rfc2518.html#STATUS_102>`_               |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`OK`                              | ``200`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.1                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.1>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`CREATED`                         | ``201`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.2                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.2>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`ACCEPTED`                        | ``202`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.3                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.3>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NON_AUTHORITATIVE_INFORMATION`   | ``203`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.4                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.4>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NO_CONTENT`                      | ``204`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.5                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.5>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`RESET_CONTENT`                   | ``205`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.6                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.6>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`PARTIAL_CONTENT`                 | ``206`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.2.7                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.7>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`MULTI_STATUS`                    | ``207`` | WEBDAV `RFC 2518, Section 10.2                                        |
-|                                          |         | <http://www.webdav.org/specs/rfc2518.html#STATUS_207>`_               |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :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                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.1>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`MOVED_PERMANENTLY`               | ``301`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.3.2                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.2>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`FOUND`                           | ``302`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.3.3                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.3>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`SEE_OTHER`                       | ``303`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.3.4                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.4>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NOT_MODIFIED`                    | ``304`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.3.5                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`USE_PROXY`                       | ``305`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.3.6                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.6>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`TEMPORARY_REDIRECT`              | ``307`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.3.8                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.8>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`BAD_REQUEST`                     | ``400`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.1                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.1>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`UNAUTHORIZED`                    | ``401`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.2                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.2>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`PAYMENT_REQUIRED`                | ``402`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.3                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.3>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`FORBIDDEN`                       | ``403`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.4                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.4>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NOT_FOUND`                       | ``404`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.5                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.5>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`METHOD_NOT_ALLOWED`              | ``405`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.6                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.6>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NOT_ACCEPTABLE`                  | ``406`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.7                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.7>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`PROXY_AUTHENTICATION_REQUIRED`   | ``407`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.8                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.8>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`REQUEST_TIMEOUT`                 | ``408`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.9                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.9>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`CONFLICT`                        | ``409`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.10                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.10>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`GONE`                            | ``410`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.11                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.11>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`LENGTH_REQUIRED`                 | ``411`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.12                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.12>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`PRECONDITION_FAILED`             | ``412`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.13                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.13>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`REQUEST_ENTITY_TOO_LARGE`        | ``413`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.14                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.14>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`REQUEST_URI_TOO_LONG`            | ``414`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.15                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.15>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`UNSUPPORTED_MEDIA_TYPE`          | ``415`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.16                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.16>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`REQUESTED_RANGE_NOT_SATISFIABLE` | ``416`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.17                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.17>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`EXPECTATION_FAILED`              | ``417`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.4.18                                                               |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.18>`_ |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`UNPROCESSABLE_ENTITY`            | ``422`` | WEBDAV, `RFC 2518, Section 10.3                                       |
-|                                          |         | <http://www.webdav.org/specs/rfc2518.html#STATUS_422>`_               |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`LOCKED`                          | ``423`` | WEBDAV `RFC 2518, Section 10.4                                        |
-|                                          |         | <http://www.webdav.org/specs/rfc2518.html#STATUS_423>`_               |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`FAILED_DEPENDENCY`               | ``424`` | WEBDAV, `RFC 2518, Section 10.5                                       |
-|                                          |         | <http://www.webdav.org/specs/rfc2518.html#STATUS_424>`_               |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`UPGRADE_REQUIRED`                | ``426`` | HTTP Upgrade to TLS,                                                  |
-|                                          |         | :rfc:`2817`, Section 6                                                |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`PRECONDITION_REQUIRED`           | ``428`` | Additional HTTP Status Codes,                                         |
-|                                          |         | :rfc:`6585`, Section 3                                                |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`TOO_MANY_REQUESTS`               | ``429`` | Additional HTTP Status Codes,                                         |
-|                                          |         | :rfc:`6585`, Section 4                                                |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`REQUEST_HEADER_FIELDS_TOO_LARGE` | ``431`` | Additional HTTP Status Codes,                                         |
-|                                          |         | :rfc:`6585`, Section 5                                                |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`INTERNAL_SERVER_ERROR`           | ``500`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.5.1                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.1>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NOT_IMPLEMENTED`                 | ``501`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.5.2                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.2>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`BAD_GATEWAY`                     | ``502`` | HTTP/1.1 `RFC 2616, Section                                           |
-|                                          |         | 10.5.3                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.3>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`SERVICE_UNAVAILABLE`             | ``503`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.5.4                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.4>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`GATEWAY_TIMEOUT`                 | ``504`` | HTTP/1.1 `RFC 2616, Section                                           |
-|                                          |         | 10.5.5                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.5>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`HTTP_VERSION_NOT_SUPPORTED`      | ``505`` | HTTP/1.1, `RFC 2616, Section                                          |
-|                                          |         | 10.5.6                                                                |
-|                                          |         | <http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.6>`_  |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`INSUFFICIENT_STORAGE`            | ``507`` | WEBDAV, `RFC 2518, Section 10.6                                       |
-|                                          |         | <http://www.webdav.org/specs/rfc2518.html#STATUS_507>`_               |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NOT_EXTENDED`                    | ``510`` | An HTTP Extension Framework,                                          |
-|                                          |         | :rfc:`2774`, Section 7                                                |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-| :const:`NETWORK_AUTHENTICATION_REQUIRED` | ``511`` | Additional HTTP Status Codes,                                         |
-|                                          |         | :rfc:`6585`, Section 6                                                |
-+------------------------------------------+---------+-----------------------------------------------------------------------+
-
-.. versionchanged:: 3.3
-   Added codes ``428``, ``429``, ``431`` and ``511`` from :rfc:`6585`.
-
-
 .. data:: responses
 
    This dictionary maps the HTTP 1.1 status codes to the W3C names.
 
    Example: ``http.client.responses[http.client.NOT_FOUND]`` is ``'Not Found'``.
 
+See :ref:`http-status-codes` for a list of HTTP status codes that are
+available in this module as constants.
+
 
 .. _httpconnection-objects:
 
@@ -458,6 +263,11 @@ HTTPConnection Objects
       Note that you must have read the whole response before you can send a new
       request to the server.
 
+   .. versionchanged:: 3.5
+      If a :exc:`ConnectionError` or subclass is raised, the
+      :class:`HTTPConnection` object will be ready to reconnect when
+      a new request is sent.
+
 
 .. method:: HTTPConnection.set_debuglevel(level)
 
@@ -496,7 +306,9 @@ HTTPConnection Objects
 
 .. method:: HTTPConnection.connect()
 
-   Connect to the server specified when the object was created.
+   Connect to the server specified when the object was created.  By default,
+   this is called automatically when making a request if the client does not
+   already have a connection.
 
 
 .. method:: HTTPConnection.close()
diff --git a/Doc/library/http.cookies.rst b/Doc/library/http.cookies.rst
index 646f2e8..7c85d09 100644
--- a/Doc/library/http.cookies.rst
+++ b/Doc/library/http.cookies.rst
@@ -143,26 +143,43 @@ Morsel Objects
 
    The keys are case-insensitive.
 
+   .. versionchanged:: 3.5
+      :meth:`~Morsel.__eq__` now takes :attr:`~Morsel.key` and :attr:`~Morsel.value`
+      into account.
+
 
 .. attribute:: Morsel.value
 
    The value of the cookie.
 
+   .. deprecated:: 3.5
+      assigning to ``value``; use :meth:`~Morsel.set` instead.
+
 
 .. attribute:: Morsel.coded_value
 
    The encoded value of the cookie --- this is what should be sent.
 
+   .. deprecated:: 3.5
+      assigning to ``coded_value``; use :meth:`~Morsel.set` instead.
+
 
 .. attribute:: Morsel.key
 
    The name of the cookie.
 
+   .. deprecated:: 3.5
+      assigning to ``key``; use :meth:`~Morsel.set` instead.
+
 
 .. method:: Morsel.set(key, value, coded_value)
 
    Set the *key*, *value* and *coded_value* attributes.
 
+   .. deprecated:: 3.5
+      The undocumented *LegalChars* parameter is ignored and will be removed in
+      a future version.
+
 
 .. method:: Morsel.isReservedKey(K)
 
@@ -193,6 +210,30 @@ Morsel Objects
    The meaning for *attrs* is the same as in :meth:`output`.
 
 
+.. method:: Morsel.update(values)
+
+   Update the values in the Morsel dictionary with the values in the dictionary
+   *values*.  Raise an error if any of the keys in the *values* dict is not a
+   valid :rfc:`2109` attribute.
+
+   .. versionchanged:: 3.5
+      an error is raised for invalid keys.
+
+
+.. method:: Morsel.copy(value)
+
+   Return a shallow copy of the Morsel object.
+
+   .. versionchanged:: 3.5
+      return a Morsel object instead of a dict.
+
+
+.. method:: Morsel.setdefault(key, value=None)
+
+   Raise an error if key is not a valid :rfc:`2109` attribute, otherwise
+   behave the same as :meth:`dict.setdefault`.
+
+
 .. _cookie-example:
 
 Example
diff --git a/Doc/library/http.rst b/Doc/library/http.rst
index a387a37..b6f2c58 100644
--- a/Doc/library/http.rst
+++ b/Doc/library/http.rst
@@ -1,7 +1,16 @@
 :mod:`http` --- HTTP modules
 ============================
 
-``http`` is a package that collects several modules for working with the
+.. module:: http
+   :synopsis: HTTP status codes and messages
+
+.. index::
+   pair: HTTP; protocol
+   single: HTTP; http (standard module)
+
+**Source code:** :source:`Lib/http/__init__.py`
+
+:mod:`http` is a package that collects several modules for working with the
 HyperText Transfer Protocol:
 
 * :mod:`http.client` is a low-level HTTP protocol client; for high-level URL
@@ -9,3 +18,105 @@ HyperText Transfer Protocol:
 * :mod:`http.server` contains basic HTTP server classes based on :mod:`socketserver`
 * :mod:`http.cookies` has utilities for implementing state management with cookies
 * :mod:`http.cookiejar` provides persistence of cookies
+
+:mod:`http` is also a module that defines a number of HTTP status codes and
+associated messages through the :class:`http.HTTPStatus` enum:
+
+.. class:: HTTPStatus
+
+   .. versionadded:: 3.5
+
+   A subclass of :class:`enum.IntEnum` that defines a set of HTTP status codes,
+   reason phrases and long descriptions written in English.
+
+   Usage::
+
+      >>> from http import HTTPStatus
+      >>> HTTPStatus.OK
+      <HTTPStatus.OK: 200>
+      >>> HTTPStatus.OK == 200
+      True
+      >>> http.HTTPStatus.OK.value
+      200
+      >>> HTTPStatus.OK.phrase
+      'OK'
+      >>> HTTPStatus.OK.description
+      'Request fulfilled, document follows'
+      >>> list(HTTPStatus)
+      [<HTTPStatus.CONTINUE: 100>, <HTTPStatus.SWITCHING_PROTOCOLS: 101>, ...]
+
+.. _http-status-codes:
+
+HTTP status codes
+-----------------
+
+Supported,
+`IANA-registered <http://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml>`_
+status codes available in :class:`http.HTTPStatus` are:
+
+======= =================================== ==================================================================
+Code    Enum Name                           Details
+======= =================================== ==================================================================
+``100`` ``CONTINUE``                        HTTP/1.1 :rfc:`7231`, Section 6.2.1
+``101`` ``SWITCHING_PROTOCOLS``             HTTP/1.1 :rfc:`7231`, Section 6.2.2
+``102`` ``PROCESSING``                      WebDAV :rfc:`2518`, Section 10.1
+``200`` ``OK``                              HTTP/1.1 :rfc:`7231`, Section 6.3.1
+``201`` ``CREATED``                         HTTP/1.1 :rfc:`7231`, Section 6.3.2
+``202`` ``ACCEPTED``                        HTTP/1.1 :rfc:`7231`, Section 6.3.3
+``203`` ``NON_AUTHORITATIVE_INFORMATION``   HTTP/1.1 :rfc:`7231`, Section 6.3.4
+``204`` ``NO_CONTENT``                      HTTP/1.1 :rfc:`7231`, Section 6.3.5
+``205`` ``RESET_CONTENT``                   HTTP/1.1 :rfc:`7231`, Section 6.3.6
+``206`` ``PARTIAL_CONTENT``                 HTTP/1.1 :rfc:`7233`, Section 4.1
+``207`` ``MULTI_STATUS``                    WebDAV :rfc:`4918`, Section 11.1
+``208`` ``ALREADY_REPORTED``                WebDAV Binding Extensions :rfc:`5842`, Section 7.1 (Experimental)
+``226`` ``IM_USED``                         Delta Encoding in HTTP :rfc:`3229`, Section 10.4.1
+``300`` ``MULTIPLE_CHOICES``                HTTP/1.1 :rfc:`7231`, Section 6.4.1
+``301`` ``MOVED_PERMANENTLY``               HTTP/1.1 :rfc:`7231`, Section 6.4.2
+``302`` ``FOUND``                           HTTP/1.1 :rfc:`7231`, Section 6.4.3
+``303`` ``SEE_OTHER``                       HTTP/1.1 :rfc:`7231`, Section 6.4.4
+``304`` ``NOT_MODIFIED``                    HTTP/1.1 :rfc:`7232`, Section 4.1
+``305`` ``USE_PROXY``                       HTTP/1.1 :rfc:`7231`, Section 6.4.5
+``307`` ``TEMPORARY_REDIRECT``              HTTP/1.1 :rfc:`7231`, Section 6.4.7
+``308`` ``PERMANENT_REDIRECT``              Permanent Redirect :rfc:`7238`, Section 3 (Experimental)
+``400`` ``BAD_REQUEST``                     HTTP/1.1 :rfc:`7231`, Section 6.5.1
+``401`` ``UNAUTHORIZED``                    HTTP/1.1 Authentication :rfc:`7235`, Section 3.1
+``402`` ``PAYMENT_REQUIRED``                HTTP/1.1 :rfc:`7231`, Section 6.5.2
+``403`` ``FORBIDDEN``                       HTTP/1.1 :rfc:`7231`, Section 6.5.3
+``404`` ``NOT_FOUND``                       HTTP/1.1 :rfc:`7231`, Section 6.5.4
+``405`` ``METHOD_NOT_ALLOWED``              HTTP/1.1 :rfc:`7231`, Section 6.5.5
+``406`` ``NOT_ACCEPTABLE``                  HTTP/1.1 :rfc:`7231`, Section 6.5.6
+``407`` ``PROXY_AUTHENTICATION_REQUIRED``   HTTP/1.1 Authentication :rfc:`7235`, Section 3.2
+``408`` ``REQUEST_TIMEOUT``                 HTTP/1.1 :rfc:`7231`, Section 6.5.7
+``409`` ``CONFLICT``                        HTTP/1.1 :rfc:`7231`, Section 6.5.8
+``410`` ``GONE``                            HTTP/1.1 :rfc:`7231`, Section 6.5.9
+``411`` ``LENGTH_REQUIRED``                 HTTP/1.1 :rfc:`7231`, Section 6.5.10
+``412`` ``PRECONDITION_FAILED``             HTTP/1.1 :rfc:`7232`, Section 4.2
+``413`` ``REQUEST_ENTITY_TOO_LARGE``        HTTP/1.1 :rfc:`7231`, Section 6.5.11
+``414`` ``REQUEST_URI_TOO_LONG``            HTTP/1.1 :rfc:`7231`, Section 6.5.12
+``415`` ``UNSUPPORTED_MEDIA_TYPE``          HTTP/1.1 :rfc:`7231`, Section 6.5.13
+``416`` ``REQUEST_RANGE_NOT_SATISFIABLE``   HTTP/1.1 Range Requests :rfc:`7233`, Section 4.4
+``417`` ``EXPECTATION_FAILED``              HTTP/1.1 :rfc:`7231`, Section 6.5.14
+``422`` ``UNPROCESSABLE_ENTITY``            WebDAV :rfc:`4918`, Section 11.2
+``423`` ``LOCKED``                          WebDAV :rfc:`4918`, Section 11.3
+``424`` ``FAILED_DEPENDENCY``               WebDAV :rfc:`4918`, Section 11.4
+``426`` ``UPGRADE_REQUIRED``                HTTP/1.1 :rfc:`7231`, Section 6.5.15
+``428`` ``PRECONDITION_REQUIRED``           Additional HTTP Status Codes :rfc:`6585`
+``429`` ``TOO_MANY_REQUESTS``               Additional HTTP Status Codes :rfc:`6585`
+``431`` ``REQUEST_HEADER_FIELDS_TOO_LARGE`` Additional HTTP Status Codes :rfc:`6585`
+``500`` ``INTERNAL_SERVER_ERROR``           HTTP/1.1 :rfc:`7231`, Section 6.6.1
+``501`` ``NOT_IMPLEMENTED``                 HTTP/1.1 :rfc:`7231`, Section 6.6.2
+``502`` ``BAD_GATEWAY``                     HTTP/1.1 :rfc:`7231`, Section 6.6.3
+``503`` ``SERVICE_UNAVAILABLE``             HTTP/1.1 :rfc:`7231`, Section 6.6.4
+``504`` ``GATEWAY_TIMEOUT``                 HTTP/1.1 :rfc:`7231`, Section 6.6.5
+``505`` ``HTTP_VERSION_NOT_SUPPORTED``      HTTP/1.1 :rfc:`7231`, Section 6.6.6
+``506`` ``VARIANT_ALSO_NEGOTIATES``         Transparent Content Negotiation in HTTP :rfc:`2295`, Section 8.1 (Experimental)
+``507`` ``INSUFFICIENT_STORAGE``            WebDAV :rfc:`4918`, Section 11.5
+``508`` ``LOOP_DETECTED``                   WebDAV Binding Extensions :rfc:`5842`, Section 7.2 (Experimental)
+``510`` ``NOT_EXTENDED``                    An HTTP Extension Framework :rfc:`2774`, Section 7 (Experimental)
+``511`` ``NETWORK_AUTHENTICATION_REQUIRED`` Additional HTTP Status Codes :rfc:`6585`, Section 6
+======= =================================== ==================================================================
+
+In order to preserve backwards compatibility, enum values are also present
+in the :mod:`http.client` module in the form of constants. The enum name is
+equal to the constant name (i.e. ``http.HTTPStatus.OK`` is also available as
+``http.client.OK``).
diff --git a/Doc/library/http.server.rst b/Doc/library/http.server.rst
index a750155..1c3e202 100644
--- a/Doc/library/http.server.rst
+++ b/Doc/library/http.server.rst
@@ -232,7 +232,7 @@ of which this module provides three different variants:
 
    .. method:: send_response_only(code, message=None)
 
-      Sends the reponse header only, used for the purposes when ``100
+      Sends the response header only, used for the purposes when ``100
       Continue`` response is sent by the server to the client. The headers not
       buffered and sent directly the output stream.If the *message* is not
       specified, the HTTP message corresponding the response *code*  is sent.
diff --git a/Doc/library/imaplib.rst b/Doc/library/imaplib.rst
index fa736fe..f263bab 100644
--- a/Doc/library/imaplib.rst
+++ b/Doc/library/imaplib.rst
@@ -37,6 +37,19 @@ base class:
    initialized. If *host* is not specified, ``''`` (the local host) is used. If
    *port* is omitted, the standard IMAP4 port (143) is used.
 
+   The :class:`IMAP4` class supports the :keyword:`with` statement.  When used
+   like this, the IMAP4 ``LOGOUT`` command is issued automatically when the
+   :keyword:`with` statement exits.  E.g.::
+
+    >>> from imaplib import IMAP4
+    >>> with IMAP4("domain.org") as M:
+    ...     M.noop()
+    ...
+    ('OK', [b'Nothing Accomplished. d25if65hy903weo.87'])
+
+   .. versionchanged:: 3.5
+      Support for the :keyword:`with` statement was added.
+
 Three exceptions are defined as attributes of the :class:`IMAP4` class:
 
 
diff --git a/Doc/library/imghdr.rst b/Doc/library/imghdr.rst
index 9e89523..c60df24 100644
--- a/Doc/library/imghdr.rst
+++ b/Doc/library/imghdr.rst
@@ -48,6 +48,16 @@ from :func:`what`:
 +------------+-----------------------------------+
 | ``'png'``  | Portable Network Graphics         |
 +------------+-----------------------------------+
+| ``'webp'`` | WebP files                        |
++------------+-----------------------------------+
+| ``'exr'``  | OpenEXR Files                     |
++------------+-----------------------------------+
+
+.. versionadded:: 3.5
+   The *exr* format was added.
+
+.. versionchanged:: 3.5
+   The *webp* type was added.
 
 You can extend the list of file types :mod:`imghdr` can recognize by appending
 to this variable:
diff --git a/Doc/library/imp.rst b/Doc/library/imp.rst
index c2dbdc5..5557346 100644
--- a/Doc/library/imp.rst
+++ b/Doc/library/imp.rst
@@ -203,11 +203,9 @@ file paths.
    value would be ``/foo/bar/__pycache__/baz.cpython-32.pyc`` for Python 3.2.
    The ``cpython-32`` string comes from the current magic tag (see
    :func:`get_tag`; if :attr:`sys.implementation.cache_tag` is not defined then
-   :exc:`NotImplementedError` will be raised).  The returned path will end in
-   ``.pyc`` when ``__debug__`` is ``True`` or ``.pyo`` for an optimized Python
-   (i.e. ``__debug__`` is ``False``).  By passing in ``True`` or ``False`` for
-   *debug_override* you can override the system's value for ``__debug__`` for
-   extension selection.
+   :exc:`NotImplementedError` will be raised). By passing in ``True`` or
+   ``False`` for *debug_override* you can override the system's value for
+   ``__debug__``, leading to optimized bytecode.
 
    *path* need not exist.
 
@@ -218,6 +216,9 @@ file paths.
    .. deprecated:: 3.4
       Use :func:`importlib.util.cache_from_source` instead.
 
+   .. versionchanged:: 3.5
+      The *debug_override* parameter no longer creates a ``.pyo`` file.
+
 
 .. function:: source_from_cache(path)
 
diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
index 91328af..82c696d 100644
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -69,6 +69,10 @@ Functions
 
     An implementation of the built-in :func:`__import__` function.
 
+    .. note::
+       Programmatic importing of modules should use :func:`import_module`
+       instead of this function.
+
 .. function:: import_module(name, package=None)
 
     Import a module. The *name* argument specifies what module to
@@ -81,12 +85,15 @@ Functions
 
     The :func:`import_module` function acts as a simplifying wrapper around
     :func:`importlib.__import__`. This means all semantics of the function are
-    derived from :func:`importlib.__import__`, including requiring the package
-    from which an import is occurring to have been previously imported
-    (i.e., *package* must already be imported). The most important difference
-    is that :func:`import_module` returns the specified package or module
-    (e.g. ``pkg.mod``), while :func:`__import__` returns the
-    top-level package or module (e.g. ``pkg``).
+    derived from :func:`importlib.__import__`. The most important difference
+    between these two functions is that :func:`import_module` returns the
+    specified package or module (e.g. ``pkg.mod``), while :func:`__import__`
+    returns the top-level package or module (e.g. ``pkg``).
+
+    If you are dynamically importing a module that was created since the
+    interpreter began execution (e.g., created a Python source file), you may
+    need to call :func:`invalidate_caches` in order for the new module to be
+    noticed by the import system.
 
     .. versionchanged:: 3.3
        Parent packages are automatically imported.
@@ -347,13 +354,16 @@ ABC hierarchy::
 
     .. method:: create_module(spec)
 
-       An optional method that returns the module object to use when
-       importing a module.  create_module() may also return ``None``,
-       indicating that the default module creation should take place
-       instead.
+       A method that returns the module object to use when
+       importing a module.  This method may return ``None``,
+       indicating that default module creation semantics should take place.
 
        .. versionadded:: 3.4
 
+       .. versionchanged:: 3.5
+          Starting in Python 3.6, this method will not be optional when
+          :meth:`exec_module` is defined.
+
     .. method:: exec_module(module)
 
        An abstract method that executes the module in its own namespace
@@ -417,7 +427,7 @@ ABC hierarchy::
 
         .. deprecated:: 3.4
            The recommended API for loading a module is :meth:`exec_module`
-           (and optionally :meth:`create_module`).  Loaders should implement
+           (and :meth:`create_module`).  Loaders should implement
            it instead of load_module().  The import machinery takes care of
            all the other responsibilities of load_module() when exec_module()
            is implemented.
@@ -499,7 +509,7 @@ ABC hierarchy::
         .. versionchanged:: 3.4
            Raises :exc:`ImportError` instead of :exc:`NotImplementedError`.
 
-    .. method:: source_to_code(data, path='<string>')
+    .. staticmethod:: source_to_code(data, path='<string>')
 
         Create a code object from Python source.
 
@@ -508,8 +518,14 @@ ABC hierarchy::
         the "path" to where the source code originated from, which can be an
         abstract concept (e.g. location in a zip file).
 
+        With the subsequent code object one can execute it in a module by
+        running ``exec(code, module.__dict__)``.
+
         .. versionadded:: 3.4
 
+        .. versionchanged:: 3.5
+           Made the method static.
+
     .. method:: exec_module(module)
 
        Implementation of :meth:`Loader.exec_module`.
@@ -695,6 +711,9 @@ find and load modules.
 
    .. versionadded:: 3.3
 
+   .. deprecated:: 3.5
+      Use :attr:`BYTECODE_SUFFIXES` instead.
+
 .. attribute:: OPTIMIZED_BYTECODE_SUFFIXES
 
    A list of strings representing the file suffixes for optimized bytecode
@@ -702,14 +721,19 @@ find and load modules.
 
    .. versionadded:: 3.3
 
+   .. deprecated:: 3.5
+      Use :attr:`BYTECODE_SUFFIXES` instead.
+
 .. attribute:: BYTECODE_SUFFIXES
 
    A list of strings representing the recognized file suffixes for bytecode
-   modules. Set to either :attr:`DEBUG_BYTECODE_SUFFIXES` or
-   :attr:`OPTIMIZED_BYTECODE_SUFFIXES` based on whether ``__debug__`` is true.
+   modules (including the leading dot).
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.5
+      The value is no longer dependent on ``__debug__``.
+
 .. attribute:: EXTENSION_SUFFIXES
 
    A list of strings representing the recognized file suffixes for
@@ -788,6 +812,11 @@ find and load modules.
 
       .. versionadded:: 3.4
 
+      .. versionchanged:: 3.5
+         If the current working directory -- represented by an empty string --
+         is no longer valid then ``None`` is returned but no value is cached
+         in :data:`sys.path_importer_cache`.
+
    .. classmethod:: find_module(fullname, path=None)
 
       A legacy wrapper around :meth:`find_spec`.
@@ -1053,23 +1082,37 @@ an :term:`importer`.
 
    .. versionadded:: 3.4
 
-.. function:: cache_from_source(path, debug_override=None)
+.. function:: cache_from_source(path, debug_override=None, *, optimization=None)
 
-   Return the :pep:`3147` path to the byte-compiled file associated with the
-   source *path*.  For example, if *path* is ``/foo/bar/baz.py`` the return
+   Return the :pep:`3147`/:pep:`488` path to the byte-compiled file associated
+   with the source *path*.  For example, if *path* is ``/foo/bar/baz.py`` the return
    value would be ``/foo/bar/__pycache__/baz.cpython-32.pyc`` for Python 3.2.
    The ``cpython-32`` string comes from the current magic tag (see
    :func:`get_tag`; if :attr:`sys.implementation.cache_tag` is not defined then
-   :exc:`NotImplementedError` will be raised).  The returned path will end in
-   ``.pyc`` when ``__debug__`` is ``True`` or ``.pyo`` for an optimized Python
-   (i.e. ``__debug__`` is ``False``).  By passing in ``True`` or ``False`` for
-   *debug_override* you can override the system's value for ``__debug__`` for
-   extension selection.
-
-   *path* need not exist.
+   :exc:`NotImplementedError` will be raised).
+
+   The *optimization* parameter is used to specify the optimization level of the
+   bytecode file. An empty string represents no optimization, so
+   ``/foo/bar/baz.py`` with an *optimization* of ``''`` will result in a
+   bytecode path of ``/foo/bar/__pycache__/baz.cpython-32.pyc``. ``None`` causes
+   the interpter's optimization level to be used. Any other value's string
+   representation being used, so ``/foo/bar/baz.py`` with an *optimization* of
+   ``2`` will lead to the bytecode path of
+   ``/foo/bar/__pycache__/baz.cpython-32.opt-2.pyc``. The string representation
+   of *optimization* can only be alphanumeric, else :exc:`ValueError` is raised.
+
+   The *debug_override* parameter is deprecated and can be used to override
+   the system's value for ``__debug__``. A ``True`` value is the equivalent of
+   setting *optimization* to the empty string. A ``False`` value is the same as
+   setting *optimization* to ``1``. If both *debug_override* an *optimization*
+   are not ``None`` then :exc:`TypeError` is raised.
 
    .. versionadded:: 3.4
 
+   .. versionchanged ::3.5
+      The *optimization* parameter was added and the *debug_override* parameter
+      was deprecated.
+
 
 .. function:: source_from_cache(path)
 
@@ -1077,7 +1120,7 @@ an :term:`importer`.
    file path.  For example, if *path* is
    ``/foo/bar/__pycache__/baz.cpython-32.pyc`` the returned path would be
    ``/foo/bar/baz.py``.  *path* need not exist, however if it does not conform
-   to :pep:`3147` format, a ``ValueError`` is raised. If
+   to :pep:`3147` or :pep:`488` format, a ``ValueError`` is raised. If
    :attr:`sys.implementation.cache_tag` is not defined,
    :exc:`NotImplementedError` is raised.
 
@@ -1123,6 +1166,21 @@ an :term:`importer`.
 
    .. versionadded:: 3.4
 
+.. function:: module_from_spec(spec)
+
+   Create a new module based on **spec** and ``spec.loader.create_module()``.
+
+   If ``spec.loader.create_module()`` does not return ``None``, then any
+   pre-existing attributes will not be reset. Also, no :exc:`AttributeError`
+   will be raised if triggered while accessing **spec** or setting an attribute
+   on the module.
+
+   This function is preferred over using :class:`types.ModuleType` to create a
+   new module as **spec** is used to set as many import-controlled attributes on
+   the module as possible.
+
+   .. versionadded:: 3.5
+
 .. decorator:: module_for_loader
 
     A :term:`decorator` for :meth:`importlib.abc.Loader.load_module`
@@ -1201,3 +1259,39 @@ an :term:`importer`.
    module will be file-based.
 
    .. versionadded:: 3.4
+
+.. class:: LazyLoader(loader)
+
+   A class which postpones the execution of the loader of a module until the
+   module has an attribute accessed.
+
+   This class **only** works with loaders that define
+   :meth:`~importlib.abc.Loader.exec_module` as control over what module type
+   is used for the module is required. For those same reasons, the loader's
+   :meth:`~importlib.abc.Loader.create_module` method will be ignored (i.e., the
+   loader's method should only return ``None``). Finally,
+   modules which substitute the object placed into :attr:`sys.modules` will
+   not work as there is no way to properly replace the module references
+   throughout the interpreter safely; :exc:`ValueError` is raised if such a
+   substitution is detected.
+
+   .. note::
+      For projects where startup time is critical, this class allows for
+      potentially minimizing the cost of loading a module if it is never used.
+      For projects where startup time is not essential then use of this class is
+      **heavily** discouraged due to error messages created during loading being
+      postponed and thus occurring out of context.
+
+   .. versionadded:: 3.5
+
+   .. classmethod:: factory(loader)
+
+      A static method which returns a callable that creates a lazy loader. This
+      is meant to be used in situations where the loader is passed by class
+      instead of by instance.
+      ::
+
+        suffixes = importlib.machinery.SOURCE_SUFFIXES
+        loader = importlib.machinery.SourceFileLoader
+        lazy_loader = importlib.util.LazyLoader.factory(loader)
+        finder = importlib.machinery.FileFinder(path, [(lazy_loader, suffixes)])
diff --git a/Doc/library/inspect.rst b/Doc/library/inspect.rst
index c540b11..471200f 100644
--- a/Doc/library/inspect.rst
+++ b/Doc/library/inspect.rst
@@ -159,6 +159,16 @@ attributes:
 |           |                 | arguments and local       |
 |           |                 | variables                 |
 +-----------+-----------------+---------------------------+
+| generator | __name__        | name                      |
++-----------+-----------------+---------------------------+
+|           | __qualname__    | qualified name            |
++-----------+-----------------+---------------------------+
+|           | gi_frame        | frame                     |
++-----------+-----------------+---------------------------+
+|           | gi_running      | is the generator running? |
++-----------+-----------------+---------------------------+
+|           | gi_code         | code                      |
++-----------+-----------------+---------------------------+
 | builtin   | __doc__         | documentation string      |
 +-----------+-----------------+---------------------------+
 |           | __name__        | original name of this     |
@@ -169,6 +179,12 @@ attributes:
 |           |                 | ``None``                  |
 +-----------+-----------------+---------------------------+
 
+.. versionchanged:: 3.5
+
+   Add ``__qualname__`` attribute to generators. The ``__name__`` attribute of
+   generators is now set from the function name, instead of the code name, and
+   it can now be modified.
+
 
 .. function:: getmembers(object[, predicate])
 
@@ -340,6 +356,9 @@ Retrieving source code
 .. function:: getdoc(object)
 
    Get the documentation string for an object, cleaned up with :func:`cleandoc`.
+   If the documentation string for an object is not provided and the object is
+   a class, a method, a property or a descriptor, retrieve the documentation
+   string from the inheritance hierarchy.
 
 
 .. function:: getcomments(object)
@@ -462,6 +481,9 @@ function.
    Signature objects are *immutable*.  Use :meth:`Signature.replace` to make a
    modified copy.
 
+   .. versionchanged:: 3.5
+      Signature objects are picklable and hashable.
+
    .. attribute:: Signature.empty
 
       A special class-level marker to specify absence of a return annotation.
@@ -506,12 +528,29 @@ function.
          >>> str(new_sig)
          "(a, b) -> 'new return anno'"
 
+   .. classmethod:: Signature.from_callable(obj)
+
+       Return a :class:`Signature` (or its subclass) object for a given callable
+       ``obj``. This method simplifies subclassing of :class:`Signature`:
+
+       ::
+
+         class MySignature(Signature):
+             pass
+         sig = MySignature.from_callable(min)
+         assert isinstance(sig, MySignature)
+
+       .. versionadded:: 3.5
+
 
 .. class:: Parameter(name, kind, \*, default=Parameter.empty, annotation=Parameter.empty)
 
    Parameter objects are *immutable*.  Instead of modifying a Parameter object,
    you can use :meth:`Parameter.replace` to create a modified copy.
 
+   .. versionchanged:: 3.5
+      Parameter objects are picklable and hashable.
+
    .. attribute:: Parameter.empty
 
       A special class-level marker to specify absence of default values and
@@ -849,11 +888,17 @@ Classes and functions
 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,
+When the following functions return "frame records," each record is a
+:term:`named tuple`
+``FrameInfo(frame, filename, lineno, function, code_context, index)``.
+The tuple contains 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.
 
+.. versionchanged:: 3.5
+   Return a named tuple instead of a tuple.
+
 .. note::
 
    Keeping references to frame objects, as found in the first element of the frame
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index 3adf6e9..f009c65 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -339,8 +339,11 @@ I/O Base Classes
       if *size* is not specified).  The current stream position isn't changed.
       This resizing can extend or reduce the current file size.  In case of
       extension, the contents of the new file area depend on the platform
-      (on most systems, additional bytes are zero-filled, on Windows they're
-      undetermined).  The new file size is returned.
+      (on most systems, additional bytes are zero-filled).  The new file size
+      is returned.
+
+   .. versionchanged:: 3.5
+      Windows will now zero-fill files when extending.
 
    .. method:: writable()
 
@@ -391,8 +394,8 @@ I/O Base Classes
    .. method:: readinto(b)
 
       Read up to ``len(b)`` bytes into :class:`bytearray` *b* and return the
-      number of bytes read.  If the object is in non-blocking mode and no
-      bytes are available, ``None`` is returned.
+      number of bytes read.  If the object is in non-blocking mode and no bytes
+      are available, ``None`` is returned.
 
    .. method:: write(b)
 
@@ -465,9 +468,10 @@ I/O Base Classes
 
    .. method:: read1(size=-1)
 
-      Read and return up to *size* bytes, with at most one call to the underlying
-      raw stream's :meth:`~RawIOBase.read` method.  This can be useful if you
-      are implementing your own buffering on top of a :class:`BufferedIOBase`
+      Read and return up to *size* bytes, with at most one call to the
+      underlying raw stream's :meth:`~RawIOBase.read` (or
+      :meth:`~RawIOBase.readinto`) method.  This can be useful if you are
+      implementing your own buffering on top of a :class:`BufferedIOBase`
       object.
 
    .. method:: readinto(b)
@@ -478,8 +482,19 @@ I/O Base Classes
       Like :meth:`read`, multiple reads may be issued to the underlying raw
       stream, unless the latter is interactive.
 
-      A :exc:`BlockingIOError` is raised if the underlying raw stream is in
-      non blocking-mode, and has no data available at the moment.
+      A :exc:`BlockingIOError` is raised if the underlying raw stream is in non
+      blocking-mode, and has no data available at the moment.
+
+   .. method:: readinto1(b)
+
+      Read up to ``len(b)`` bytes into bytearray *b*, ,using at most one call to
+      the underlying raw stream's :meth:`~RawIOBase.read` (or
+      :meth:`~RawIOBase.readinto`) method. Return the number of bytes read.
+
+      A :exc:`BlockingIOError` is raised if the underlying raw stream is in non
+      blocking-mode, and has no data available at the moment.
+
+      .. versionadded:: 3.5
 
    .. method:: write(b)
 
@@ -507,9 +522,12 @@ Raw File I/O
    The *name* can be one of two things:
 
    * a character string or :class:`bytes` object representing the path to the
-     file which will be opened;
+     file which will be opened. In this case closefd must be True (the default)
+     otherwise an error will be raised.
    * an integer representing the number of an existing OS-level file descriptor
-     to which the resulting :class:`FileIO` object will give access.
+     to which the resulting :class:`FileIO` object will give access. When the
+     FileIO object is closed this fd will be closed as well, unless *closefd*
+     is set to ``False``.
 
    The *mode* can be ``'r'``, ``'w'``, ``'x'`` or ``'a'`` for reading
    (default), writing, exclusive creation or appending. The file will be
@@ -598,6 +616,11 @@ than raw I/O does.
 
       In :class:`BytesIO`, this is the same as :meth:`read`.
 
+   .. method:: readinto1()
+
+      In :class:`BytesIO`, this is the same as :meth:`readinto`.
+
+      .. versionadded:: 3.5
 
 .. class:: BufferedReader(raw, buffer_size=DEFAULT_BUFFER_SIZE)
 
@@ -807,11 +830,13 @@ Text I/O
    exception if there is an encoding error (the default of ``None`` has the same
    effect), or pass ``'ignore'`` to ignore errors.  (Note that ignoring encoding
    errors can lead to data loss.)  ``'replace'`` causes a replacement marker
-   (such as ``'?'``) to be inserted where there is malformed data.  When
-   writing, ``'xmlcharrefreplace'`` (replace with the appropriate XML character
-   reference) or ``'backslashreplace'`` (replace with backslashed escape
-   sequences) can be used.  Any other error handling name that has been
-   registered with :func:`codecs.register_error` is also valid.
+   (such as ``'?'``) to be inserted where there is malformed data.
+   ``'backslashreplace'`` causes malformed data to be replaced by a
+   backslashed escape sequence.  When writing, ``'xmlcharrefreplace'``
+   (replace with the appropriate XML character reference)  or ``'namereplace'``
+   (replace with ``\N{...}`` escape sequences) can be used.  Any other error
+   handling name that has been registered with
+   :func:`codecs.register_error` is also valid.
 
    .. index::
       single: universal newlines; io.TextIOWrapper class
diff --git a/Doc/library/ipaddress.rst b/Doc/library/ipaddress.rst
index ca87980..7b59440 100644
--- a/Doc/library/ipaddress.rst
+++ b/Doc/library/ipaddress.rst
@@ -103,7 +103,7 @@ write code that handles both IP versions correctly.
    1. A string in decimal-dot notation, consisting of four decimal integers in
       the inclusive range 0-255, separated by dots (e.g. ``192.168.0.1``). Each
       integer represents an octet (byte) in the address. Leading zeroes are
-      tolerated only for values less then 8 (as there is no ambiguity
+      tolerated only for values less than 8 (as there is no ambiguity
       between the decimal and octal interpretations of such strings).
    2. An integer that fits into 32 bits.
    3. An integer packed into a :class:`bytes` object of length 4 (most
@@ -146,6 +146,20 @@ write code that handles both IP versions correctly.
       the appropriate length (most significant octet first). This is 4 bytes
       for IPv4 and 16 bytes for IPv6.
 
+   .. attribute:: reverse_pointer
+
+      The name of the reverse DNS PTR record for the IP address, e.g.::
+
+          >>> ipaddress.ip_address("127.0.0.1").reverse_pointer
+          '1.0.0.127.in-addr.arpa'
+          >>> ipaddress.ip_address("2001:db8::1").reverse_pointer
+          '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa'
+
+      This is the name that could be used for performing a PTR lookup, not the
+      resolved hostname itself.
+
+   .. versionadded:: 3.5
+
    .. attribute:: is_multicast
 
       ``True`` if the address is reserved for multicast use.  See
@@ -226,6 +240,7 @@ write code that handles both IP versions correctly.
    :class:`IPv4Address` class:
 
    .. attribute:: packed
+   .. attribute:: reverse_pointer
    .. attribute:: version
    .. attribute:: max_prefixlen
    .. attribute:: is_multicast
@@ -377,6 +392,12 @@ so to avoid duplication they are only documented for :class:`IPv4Network`.
    3. An integer packed into a :class:`bytes` object of length 4, big-endian.
       The interpretation is similar to an integer *address*.
 
+   4. A two-tuple of an address description and a netmask, where the address
+      description is either a string, a 32-bits integer, a 4-bytes packed
+      integer, or an existing IPv4Address object; and the netmask is either
+      an integer representing the prefix length (e.g. ``24``) or a string
+      representing the prefix mask (e.g. ``255.255.255.0``).
+
    An :exc:`AddressValueError` is raised if *address* is not a valid IPv4
    address.  A :exc:`NetmaskValueError` is raised if the mask is not valid for
    an IPv4 address.
@@ -389,6 +410,10 @@ so to avoid duplication they are only documented for :class:`IPv4Network`.
    objects will raise :exc:`TypeError` if the argument's IP version is
    incompatible to ``self``
 
+   .. versionchanged:: 3.5
+
+      Added the two-tuple form for the *address* constructor parameter.
+
    .. attribute:: version
    .. attribute:: max_prefixlen
 
@@ -553,6 +578,11 @@ so to avoid duplication they are only documented for :class:`IPv4Network`.
    3. An integer packed into a :class:`bytes` object of length 16, bit-endian.
       The interpretation is similar to an integer *address*.
 
+   4. A two-tuple of an address description and a netmask, where the address
+      description is either a string, a 128-bits integer, a 16-bytes packed
+      integer, or an existing IPv4Address object; and the netmask is an
+      integer representing the prefix length.
+
    An :exc:`AddressValueError` is raised if *address* is not a valid IPv6
    address.  A :exc:`NetmaskValueError` is raised if the mask is not valid for
    an IPv6 address.
@@ -561,6 +591,10 @@ so to avoid duplication they are only documented for :class:`IPv4Network`.
    then :exc:`ValueError` is raised.  Otherwise, the host bits are masked out
    to determine the appropriate network address.
 
+   .. versionchanged:: 3.5
+
+      Added the two-tuple form for the *address* constructor parameter.
+
    .. attribute:: version
    .. attribute:: max_prefixlen
    .. attribute:: is_multicast
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index f489535..8c7592d 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -87,10 +87,15 @@ loops that truncate the stream.
 
 .. function:: accumulate(iterable[, func])
 
-    Make an iterator that returns accumulated sums. Elements may be any addable
-    type including :class:`~decimal.Decimal` or :class:`~fractions.Fraction`.
-    If the optional *func* argument is supplied, it should be a function of two
-    arguments and it will be used instead of addition.
+    Make an iterator that returns accumulated sums, or accumulated
+    results of other binary functions (specified via the optional
+    *func* argument).  If *func* is supplied, it should be a function
+    of two arguments. Elements of the input *iterable* may be any type
+    that can be accepted as arguments to *func*. (For example, with
+    the default operation of addition, elements may be any addable
+    type including :class:`~decimal.Decimal` or
+    :class:`~fractions.Fraction`.) If the input iterable is empty, the
+    output iterable will also be empty.
 
     Equivalent to::
 
@@ -99,7 +104,10 @@ loops that truncate the stream.
             # accumulate([1,2,3,4,5]) --> 1 3 6 10 15
             # accumulate([1,2,3,4,5], operator.mul) --> 1 2 6 24 120
             it = iter(iterable)
-            total = next(it)
+            try:
+                total = next(it)
+            except StopIteration:
+                return
             yield total
             for element in it:
                 total = func(total, element)
@@ -400,7 +408,10 @@ loops that truncate the stream.
           def _grouper(self, tgtkey):
               while self.currkey == tgtkey:
                   yield self.currvalue
-                  self.currvalue = next(self.it)    # Exit on StopIteration
+                  try:
+                      self.currvalue = next(self.it)
+                  except StopIteration:
+                      return
                   self.currkey = self.keyfunc(self.currvalue)
 
 
@@ -424,7 +435,10 @@ loops that truncate the stream.
           # islice('ABCDEFG', 0, None, 2) --> A C E G
           s = slice(*args)
           it = iter(range(s.start or 0, s.stop or sys.maxsize, s.step or 1))
-          nexti = next(it)
+          try:
+              nexti = next(it)
+          except StopIteration:
+              return
           for i, element in enumerate(iterable):
               if i == nexti:
                   yield element
@@ -582,7 +596,10 @@ loops that truncate the stream.
             def gen(mydeque):
                 while True:
                     if not mydeque:             # when the local deque is empty
-                        newval = next(it)       # fetch a new value and
+                        try:
+                            newval = next(it)   # fetch a new value and
+                        except StopIteration:
+                            return
                         for d in deques:        # load it to all the deques
                             d.append(newval)
                     yield mydeque.popleft()
@@ -657,6 +674,11 @@ which incur interpreter overhead.
        "Return function(0), function(1), ..."
        return map(function, count(start))
 
+   def tail(n, iterable):
+       "Return an iterator over the last n items"
+       # tail(3, 'ABCDEFG') --> E F G
+       return iter(collections.deque(iterable, maxlen=n))
+
    def consume(iterator, n):
        "Advance the iterator n-steps ahead. If n is none, consume entirely."
        # Use functions that consume iterators at C speed.
diff --git a/Doc/library/json.rst b/Doc/library/json.rst
index 6f5f8b1..49bb090 100644
--- a/Doc/library/json.rst
+++ b/Doc/library/json.rst
@@ -106,6 +106,8 @@ Using json.tool from the shell to validate and pretty-print::
     $ echo '{1.2:3.4}' | python -m json.tool
     Expecting property name enclosed in double quotes: line 1 column 2 (char 1)
 
+See :ref:`json-commandline` for detailed documentation.
+
 .. highlight:: python3
 
 .. note::
@@ -248,7 +250,7 @@ Basic Usage
    will be passed to the constructor of the class.
 
    If the data being deserialized is not a valid JSON document, a
-   :exc:`ValueError` will be raised.
+   :exc:`JSONDecodeError` will be raised.
 
 .. function:: loads(s, encoding=None, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)
 
@@ -259,7 +261,7 @@ Basic Usage
    *encoding* which is ignored and deprecated.
 
    If the data being deserialized is not a valid JSON document, a
-   :exc:`ValueError` will be raised.
+   :exc:`JSONDecodeError` will be raised.
 
 Encoders and Decoders
 ---------------------
@@ -332,13 +334,16 @@ Encoders and Decoders
    ``'\n'``, ``'\r'`` and ``'\0'``.
 
    If the data being deserialized is not a valid JSON document, a
-   :exc:`ValueError` will be raised.
+   :exc:`JSONDecodeError` will be raised.
 
    .. method:: decode(s)
 
       Return the Python representation of *s* (a :class:`str` instance
       containing a JSON document)
 
+      :exc:`JSONDecodeError` will be raised if the given JSON document is not
+      valid.
+
    .. method:: raw_decode(s)
 
       Decode a JSON document from *s* (a :class:`str` beginning with a
@@ -467,6 +472,36 @@ Encoders and Decoders
                 mysocket.write(chunk)
 
 
+Exceptions
+----------
+
+.. exception:: JSONDecodeError(msg, doc, pos, end=None)
+
+    Subclass of :exc:`ValueError` with the following additional attributes:
+
+    .. attribute:: msg
+
+        The unformatted error message.
+
+    .. attribute:: doc
+
+        The JSON document being parsed.
+
+    .. attribute:: pos
+
+        The start index of *doc* where parsing failed.
+
+    .. attribute:: lineno
+
+        The line corresponding to *pos*.
+
+    .. attribute:: colno
+
+        The column corresponding to *pos*.
+
+   .. versionadded:: 3.5
+
+
 Standard Compliance and Interoperability
 ----------------------------------------
 
@@ -588,6 +623,68 @@ when serializing Python :class:`int` values of extremely large magnitude, or
 when serializing instances of "exotic" numerical types such as
 :class:`decimal.Decimal`.
 
+.. highlight:: bash
+.. module:: json.tool
+
+.. _json-commandline:
+
+Command Line Interface
+----------------------
+
+The :mod:`json.tool` module provides a simple command line interface to validate
+and pretty-print JSON objects.
+
+If the optional ``infile`` and ``outfile`` arguments are not
+specified, :attr:`sys.stdin` and :attr:`sys.stdout` will be used respectively::
+
+    $ echo '{"json": "obj"}' | python -m json.tool
+    {
+        "json": "obj"
+    }
+    $ echo '{1.2:3.4}' | python -m json.tool
+    Expecting property name enclosed in double quotes: line 1 column 2 (char 1)
+
+.. versionchanged:: 3.5
+   The output is now in the same order as the input. Use the
+   :option:`--sort-keys` option to sort the output of dictionaries
+   alphabetically by key.
+
+Command line options
+^^^^^^^^^^^^^^^^^^^^
+
+.. cmdoption:: infile
+
+   The JSON file to be validated or pretty-printed::
+
+      $ python -m json.tool mp_films.json
+      [
+          {
+              "title": "And Now for Something Completely Different",
+              "year": 1971
+          },
+          {
+              "title": "Monty Python and the Holy Grail",
+              "year": 1975
+          }
+      ]
+
+   If *infile* is not specified, read from :attr:`sys.stdin`.
+
+.. cmdoption:: outfile
+
+   Write the output of the *infile* to the given *outfile*. Otherwise, write it
+   to :attr:`sys.stdout`.
+
+.. cmdoption:: --sort-keys
+
+   Sort the output of dictionaries alphabetically by key.
+
+   .. versionadded:: 3.5
+
+.. cmdoption:: -h, --help
+
+   Show the help message.
+
 
 .. rubric:: Footnotes
 
diff --git a/Doc/library/linecache.rst b/Doc/library/linecache.rst
index f18b1cd..6c92cc5 100644
--- a/Doc/library/linecache.rst
+++ b/Doc/library/linecache.rst
@@ -47,6 +47,14 @@ The :mod:`linecache` module defines the following functions:
    changed on disk, and you require the updated version.  If *filename* is omitted,
    it will check all the entries in the cache.
 
+.. function:: lazycache(filename, module_globals)
+
+   Capture enough detail about a non-file based module to permit getting its
+   lines later via :func:`getline` even if *module_globals* is None in the later
+   call. This avoids doing I/O until a line is actually needed, without having
+   to carry the module globals around indefinitely.
+
+   .. versionadded:: 3.5
 
 Example::
 
diff --git a/Doc/library/locale.rst b/Doc/library/locale.rst
index 9600193..bc7f5f9 100644
--- a/Doc/library/locale.rst
+++ b/Doc/library/locale.rst
@@ -387,6 +387,14 @@ The :mod:`locale` module defines the following exception and functions:
    ``str(float)``, but takes the decimal point into account.
 
 
+.. function:: delocalize(string)
+
+    Converts a string into a normalized number string, following the
+    :const:`LC_NUMERIC` settings.
+
+    .. versionadded:: 3.5
+
+
 .. function:: atof(string)
 
    Converts a string to a floating point number, following the :const:`LC_NUMERIC`
diff --git a/Doc/library/logging.handlers.rst b/Doc/library/logging.handlers.rst
index 63aba1e..67403a9 100644
--- a/Doc/library/logging.handlers.rst
+++ b/Doc/library/logging.handlers.rst
@@ -436,7 +436,7 @@ sends logging output to a network socket. The base class uses a TCP socket.
    .. method:: createSocket()
 
       Tries to create a socket; on failure, uses an exponential back-off
-      algorithm.  On intial failure, the handler will drop the message it was
+      algorithm.  On initial failure, the handler will drop the message it was
       trying to send.  When subsequent messages are handled by the same
       instance, it will not try connecting until some time has passed.  The
       default parameters are such that the initial delay is one second, and if
@@ -853,7 +853,7 @@ supports sending logging messages to a Web server, using either ``GET`` or
    credentials, you should also specify secure=True so that your userid and
    password are not passed in cleartext across the wire.
 
-   .. versionchanged:: 3.4.3
+   .. versionchanged:: 3.5
       The *context* parameter was added.
 
    .. method:: mapLogRecord(record)
@@ -953,13 +953,20 @@ applications where threads servicing clients need to respond as quickly as
 possible, while any potentially slow operations (such as sending an email via
 :class:`SMTPHandler`) are done on a separate thread.
 
-.. class:: QueueListener(queue, *handlers)
+.. class:: QueueListener(queue, *handlers, respect_handler_level=False)
 
    Returns a new instance of the :class:`QueueListener` class. The instance is
    initialized with the queue to send messages to and a list of handlers which
    will handle entries placed on the queue. The queue can be any queue-
    like object; it's passed as-is to the :meth:`dequeue` method, which needs
-   to know how to get messages from it.
+   to know how to get messages from it. If ``respect_handler_level`` is ``True``,
+   a handler's level is respected (compared with the level for the message) when
+   deciding whether to pass messages to that handler; otherwise, the behaviour
+   is as in previous Python versions - to always pass each message to each
+   handler.
+
+   .. versionchanged:: 3.5
+      The ``respect_handler_levels`` argument was added.
 
    .. method:: dequeue(block)
 
diff --git a/Doc/library/logging.rst b/Doc/library/logging.rst
index 96861a7..7915c27 100644
--- a/Doc/library/logging.rst
+++ b/Doc/library/logging.rst
@@ -159,11 +159,13 @@ is the module's name in the Python package namespace.
    *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 three keyword arguments in *kwargs* which are inspected: *exc_info*
-   which, if it does not evaluate as false, causes exception information to be
+   There are three keyword arguments in *kwargs* which are inspected:
+   *exc_info*, *stack_info*, and *extra*.
+
+   If *exc_info* does not evaluate as false, it 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.
+   :func:`sys.exc_info`) or an exception instance is provided, it is used;
+   otherwise, :func:`sys.exc_info` is called to get the exception information.
 
    The second optional keyword argument is *stack_info*, which defaults to
    ``False``. If true, stack information is added to the logging
@@ -220,6 +222,9 @@ is the module's name in the Python package namespace.
    .. versionadded:: 3.2
       The *stack_info* parameter was added.
 
+   .. versionchanged:: 3.5
+      The *exc_info* parameter can now accept exception instances.
+
 
 .. method:: Logger.info(msg, *args, **kwargs)
 
diff --git a/Doc/library/lzma.rst b/Doc/library/lzma.rst
index b71051d..0546005 100644
--- a/Doc/library/lzma.rst
+++ b/Doc/library/lzma.rst
@@ -110,6 +110,10 @@ Reading and writing compressed files
    .. versionchanged:: 3.4
       Added support for the ``"x"`` and ``"xb"`` modes.
 
+   .. versionchanged:: 3.5
+      The :meth:`~io.BufferedIOBase.read` method now accepts an argument of
+      ``None``.
+
 
 Compressing and decompressing data in memory
 --------------------------------------------
@@ -221,13 +225,32 @@ Compressing and decompressing data in memory
       decompress a multi-stream input with :class:`LZMADecompressor`, you must
       create a new decompressor for each stream.
 
-   .. method:: decompress(data)
+   .. method:: decompress(data, max_length=-1)
+
+      Decompress *data* (a :term:`bytes-like object`), returning
+      uncompressed data as bytes. Some of *data* may be buffered
+      internally, for use in later calls to :meth:`decompress`. The
+      returned data should be concatenated with the output of any
+      previous calls to :meth:`decompress`.
+
+      If *max_length* is nonnegative, returns at most *max_length*
+      bytes of decompressed data. If this limit is reached and further
+      output can be produced, the :attr:`~.needs_input` attribute will
+      be set to ``False``. In this case, the next call to
+      :meth:`~.decompress` may provide *data* as ``b''`` to obtain
+      more of the output.
+
+      If all of the input data was decompressed and returned (either
+      because this was less than *max_length* bytes, or because
+      *max_length* was negative), the :attr:`~.needs_input` attribute
+      will be set to ``True``.
 
-      Decompress *data* (a :class:`bytes` object), returning a :class:`bytes`
-      object containing the decompressed data for at least part of the input.
-      Some of *data* may be buffered internally, for use in later calls to
-      :meth:`decompress`. The returned data should be concatenated with the
-      output of any previous calls to :meth:`decompress`.
+      Attempting to decompress data after the end of stream is reached
+      raises an `EOFError`.  Any data found after the end of the
+      stream is ignored and saved in the :attr:`~.unused_data` attribute.
+
+      .. versionchanged:: 3.5
+         Added the *max_length* parameter.
 
    .. attribute:: check
 
@@ -245,6 +268,12 @@ Compressing and decompressing data in memory
 
       Before the end of the stream is reached, this will be ``b""``.
 
+   .. attribute:: needs_input
+
+      ``False`` if the :meth:`.decompress` method can provide more
+      decompressed data before requiring new uncompressed input.
+
+      .. versionadded:: 3.5
 
 .. function:: compress(data, format=FORMAT_XZ, check=-1, preset=None, filters=None)
 
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 3c41672..eda0056 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -383,6 +383,22 @@ Constants
    The mathematical constant e = 2.718281..., to available precision.
 
 
+.. data:: inf
+
+   A floating-point positive infinity.  (For negative infinity, use
+   ``-math.inf``.)  Equivalent to the output of ``float('inf')``.
+
+   .. versionadded:: 3.5
+
+
+.. data:: nan
+
+   A floating-point "not a number" (NaN) value.  Equivalent to the output of
+   ``float('nan')``.
+
+   .. versionadded:: 3.5
+
+
 .. impl-detail::
 
    The :mod:`math` module consists mostly of thin wrappers around the platform C
diff --git a/Doc/library/mmap.rst b/Doc/library/mmap.rst
index 18e05e3..b74a823 100644
--- a/Doc/library/mmap.rst
+++ b/Doc/library/mmap.rst
@@ -174,6 +174,9 @@ To map anonymous memory, -1 should be passed as the fileno along with the length
       Optional arguments *start* and *end* are interpreted as in slice notation.
       Returns ``-1`` on failure.
 
+      .. versionchanged: 3.5
+         Writable :term:`bytes-like object` is now accepted.
+
 
    .. method:: flush([offset[, size]])
 
@@ -234,6 +237,9 @@ To map anonymous memory, -1 should be passed as the fileno along with the length
       Optional arguments *start* and *end* are interpreted as in slice notation.
       Returns ``-1`` on failure.
 
+      .. versionchanged: 3.5
+         Writable :term:`bytes-like object` is now accepted.
+
 
    .. method:: seek(pos[, whence])
 
@@ -261,6 +267,9 @@ To map anonymous memory, -1 should be passed as the fileno along with the length
       were written. If the mmap was created with :const:`ACCESS_READ`, then
       writing to it will raise a :exc:`TypeError` exception.
 
+      .. versionchanged: 3.5
+         Writable :term:`bytes-like object` is now accepted.
+
 
    .. method:: write_byte(byte)
 
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index 4d5f308..8703f8f 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -1352,6 +1352,9 @@ processes.
    Note that accessing the ctypes object through the wrapper can be a lot slower
    than accessing the raw ctypes object.
 
+   .. versionchanged:: 3.5
+      Synchronized objects support the :term:`context manager` protocol.
+
 
 The table below compares the syntax for creating shared ctypes objects from
 shared memory with the normal ctypes syntax.  (In the table ``MyStruct`` is some
@@ -1839,9 +1842,9 @@ itself.  This means, for example, that one shared object can contain a second:
          >>> l = manager.list(range(10))
          >>> l._callmethod('__len__')
          10
-         >>> l._callmethod('__getitem__', (slice(2, 7),))  # equiv to `l[2:7]`
+         >>> l._callmethod('__getitem__', (slice(2, 7),)) # equivalent to l[2:7]
          [2, 3, 4, 5, 6]
-         >>> l._callmethod('__getitem__', (20,))     # equiv to `l[20]`
+         >>> l._callmethod('__getitem__', (20,))          # equivalent to l[20]
          Traceback (most recent call last):
          ...
          IndexError: list index out of range
diff --git a/Doc/library/operator.rst b/Doc/library/operator.rst
index f9e2a3d..c01e63b 100644
--- a/Doc/library/operator.rst
+++ b/Doc/library/operator.rst
@@ -138,6 +138,14 @@ The mathematical and bitwise operations are the most numerous:
    Return ``a * b``, for *a* and *b* numbers.
 
 
+.. function:: matmul(a, b)
+              __matmul__(a, b)
+
+   Return ``a @ b``.
+
+   .. versionadded:: 3.5
+
+
 .. function:: neg(obj)
               __neg__(obj)
 
@@ -391,6 +399,8 @@ Python syntax and the functions in the :mod:`operator` module.
 +-----------------------+-------------------------+---------------------------------------+
 | Multiplication        | ``a * b``               | ``mul(a, b)``                         |
 +-----------------------+-------------------------+---------------------------------------+
+| Matrix Multiplication | ``a @ b``               | ``matmul(a, b)``                      |
++-----------------------+-------------------------+---------------------------------------+
 | Negation (Arithmetic) | ``- a``                 | ``neg(a)``                            |
 +-----------------------+-------------------------+---------------------------------------+
 | Negation (Logical)    | ``not a``               | ``not_(a)``                           |
@@ -499,6 +509,14 @@ will perform the update, so no subsequent assignment is necessary:
    ``a = imul(a, b)`` is equivalent to ``a *= b``.
 
 
+.. function:: imatmul(a, b)
+              __imatmul__(a, b)
+
+   ``a = imatmul(a, b)`` is equivalent to ``a @= b``.
+
+   .. versionadded:: 3.5
+
+
 .. function:: ior(a, b)
               __ior__(a, b)
 
diff --git a/Doc/library/os.path.rst b/Doc/library/os.path.rst
index 92631b2..e4fe44e 100644
--- a/Doc/library/os.path.rst
+++ b/Doc/library/os.path.rst
@@ -66,11 +66,24 @@ the :mod:`glob` module.)
    empty string (``''``).
 
 
+.. function:: commonpath(paths)
+
+   Return the longest common sub-path of each pathname in the sequence
+   *paths*.  Raise ValueError if *paths* contains both absolute and relative
+   pathnames, or if *paths* is empty.  Unlike :func:`commonprefix`, this
+   returns a valid path.
+
+   Availability: Unix, Windows
+
+   .. versionadded:: 3.5
+
+
 .. 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.
+   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.  To obtain a valid path, see :func:`commonpath`.
 
 
 .. function:: dirname(path)
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 41efccd..bd09937 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -78,9 +78,10 @@ uses the file system encoding to perform this conversion (see
 
 .. versionchanged:: 3.1
    On some systems, conversion using the file system encoding may fail. In this
-   case, Python uses the ``surrogateescape`` encoding error handler, which means
-   that undecodable bytes are replaced by a Unicode character U+DCxx on
-   decoding, and these are again translated to the original byte on encoding.
+   case, Python uses the :ref:`surrogateescape encoding error handler
+   <surrogateescape>`, which means that undecodable bytes are replaced by a
+   Unicode character U+DCxx on decoding, and these are again translated to the
+   original byte on encoding.
 
 
 The file system encoding must guarantee to successfully decode all bytes
@@ -804,8 +805,21 @@ as internal buffering of data.
    most *length* bytes in size.  As of Python 3.3, this is equivalent to
    ``os.truncate(fd, length)``.
 
+   Availability: Unix, Windows.
+
+   .. versionchanged:: 3.5
+      Added support for Windows
+
+.. function:: get_blocking(fd)
+
+   Get the blocking mode of the file descriptor: ``False`` if the
+   :data:`O_NONBLOCK` flag is set, ``True`` if the flag is cleared.
+
+   See also :func:`set_blocking` and :meth:`socket.socket.setblocking`.
+
    Availability: Unix.
 
+   .. versionadded:: 3.5
 
 .. function:: isatty(fd)
 
@@ -893,6 +907,11 @@ as internal buffering of data.
    .. versionadded:: 3.3
       The *dir_fd* argument.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 The following constants are options for the *flags* parameter to the
 :func:`~os.open` function.  They can be combined using the bitwise OR operator
 ``|``.  Some of them are not available on all platforms.  For descriptions of
@@ -1070,6 +1089,11 @@ or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Window
       :func:`popen` or :func:`fdopen`, or :data:`sys.stdin`, use its
       :meth:`~file.read` or :meth:`~file.readline` methods.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: sendfile(out, in, offset, nbytes)
               sendfile(out, in, offset, nbytes, headers=None, trailers=None, flags=0)
@@ -1107,6 +1131,18 @@ or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Window
    .. versionadded:: 3.3
 
 
+.. function:: set_blocking(fd, blocking)
+
+   Set the blocking mode of the specified file descriptor. Set the
+   :data:`O_NONBLOCK` flag if blocking is ``False``, clear the flag otherwise.
+
+   See also :func:`get_blocking` and :meth:`socket.socket.setblocking`.
+
+   Availability: Unix.
+
+   .. versionadded:: 3.5
+
+
 .. data:: SF_NODISKIO
           SF_MNOWAIT
           SF_SYNC
@@ -1173,6 +1209,11 @@ or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Window
       :func:`fdopen`, or :data:`sys.stdout` or :data:`sys.stderr`, use its
       :meth:`~file.write` method.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: writev(fd, buffers)
 
@@ -1577,6 +1618,11 @@ features:
 
    Availability: Unix, Windows.
 
+   .. seealso::
+
+      The :func:`scandir` function returns the directory entries with more
+      information than just the name.
+
    .. versionchanged:: 3.2
       The *path* parameter became optional.
 
@@ -1869,6 +1915,178 @@ features:
       The *dir_fd* parameter.
 
 
+.. function:: scandir(path='.')
+
+   Return an iterator of :class:`DirEntry` objects corresponding to the entries
+   in the directory given by *path*. The entries are yielded in arbitrary
+   order, and the special entries ``'.'`` and ``'..'`` are not included.
+
+   On Windows, *path* must of type :class:`str`. On POSIX, *path* can be of
+   type :class:`str` or :class:`bytes`.  If *path* is of type :class:`bytes`,
+   the :attr:`~DirEntry.name` and :attr:`~DirEntry.path` attributes of
+   :class:`DirEntry` are also of type ``bytes``. Use :func:`~os.fsencode` and
+   :func:`~os.fsdecode` to encode and decode paths.
+
+   The :func:`scandir` function is recommended, instead of :func:`listdir`,
+   when the file type of entries is used. In most cases, the file type of a
+   :class:`DirEntry` is retrieved directly by :func:`scandir`, no system call
+   is required. If only the name of entries is used, :func:`listdir` can
+   be more efficient than :func:`scandir`.
+
+   The following example shows a simple use of :func:`scandir` to display all
+   the files excluding directories in the given *path* that don't start with
+   ``'.'``::
+
+      for entry in os.scandir(path):
+         if not entry.name.startswith('.') and entry.is_file():
+             print(entry.name)
+
+   .. note::
+
+      On Unix-based systems, :func:`scandir` uses the system's
+      `opendir() <http://pubs.opengroup.org/onlinepubs/009695399/functions/opendir.html>`_
+      and
+      `readdir() <http://pubs.opengroup.org/onlinepubs/009695399/functions/readdir_r.html>`_
+      functions. On Windows, it uses the Win32
+      `FindFirstFileW <http://msdn.microsoft.com/en-us/library/windows/desktop/aa364418(v=vs.85).aspx>`_
+      and
+      `FindNextFileW <http://msdn.microsoft.com/en-us/library/windows/desktop/aa364428(v=vs.85).aspx>`_
+      functions.
+
+   .. seealso::
+
+      The :func:`listdir` function returns the names of the directory entries.
+
+   .. versionadded:: 3.5
+
+
+.. class:: DirEntry
+
+   Object yielded by :func:`scandir` to expose the file path and other file
+   attributes of a directory entry.
+
+   :func:`scandir` will provide as much of this information as possible without
+   making additional system calls. When a ``stat()`` or ``lstat()`` system call
+   is made, the ``DirEntry`` object cache the result .
+
+   ``DirEntry`` instances are not intended to be stored in long-lived data
+   structures; if you know the file metadata has changed or if a long time has
+   elapsed since calling :func:`scandir`, call ``os.stat(entry.path)`` to fetch
+   up-to-date information.
+
+   Because the ``DirEntry`` methods can make operating system calls, they may
+   also raise :exc:`OSError`. For example, if a file is deleted between calling
+   :func:`scandir` and calling :func:`DirEntry.stat`, a
+   :exc:`FileNotFoundError` exception can be raised. Unfortunately, the
+   behaviour on errors depends on the platform. If you need very fine-grained
+   control over errors, you can catch :exc:`OSError` when calling one of the
+   ``DirEntry`` methods and handle as appropriate.
+
+   Attributes and methods on a ``DirEntry`` instance are as follows:
+
+   .. attribute:: name
+
+      The entry's base filename, relative to the :func:`scandir` *path*
+      argument.
+
+      The :attr:`name` type is :class:`str`. On POSIX, it can be of type
+      :class:`bytes` if the type of the :func:`scandir` *path* argument is also
+      :class:`bytes`. Use :func:`~os.fsdecode` to decode the name.
+
+   .. attribute:: path
+
+      The entry's full path name: equivalent to ``os.path.join(scandir_path,
+      entry.name)`` where *scandir_path* is the :func:`scandir` *path*
+      argument.  The path is only absolute if the :func:`scandir` *path*
+      argument is absolute.
+
+      The :attr:`name` type is :class:`str`. On POSIX, it can be of type
+      :class:`bytes` if the type of the :func:`scandir` *path* argument is also
+      :class:`bytes`. Use :func:`~os.fsdecode` to decode the path.
+
+   .. method:: inode()
+
+      Return the inode number of the entry.
+
+      The result is cached in the object, use ``os.stat(entry.path,
+      follow_symlinks=False).st_ino`` to fetch up-to-date information.
+
+      On POSIX, no system call is required.
+
+   .. method:: is_dir(\*, follow_symlinks=True)
+
+      If *follow_symlinks* is ``True`` (the default), return ``True`` if the
+      entry is a directory or a symbolic link pointing to a directory,
+      return ``False`` if it points to another kind of file, if it doesn't
+      exist anymore or if it is a broken symbolic link.
+
+      If *follow_symlinks* is ``False``, return ``True`` only if this entry
+      is a directory, return ``False`` if it points to a symbolic link or
+      another kind of file, if the entry doesn't exist anymore or if it is a
+      broken symbolic link
+
+      The result is cached in the object. Call :func:`stat.S_ISDIR` with
+      :func:`os.stat` to fetch up-to-date information.
+
+      The method can raise :exc:`OSError`, such as :exc:`PermissionError`,
+      but :exc:`FileNotFoundError` is catched.
+
+      In most cases, no system call is required.
+
+   .. method:: is_file(\*, follow_symlinks=True)
+
+      If *follow_symlinks* is ``True`` (the default), return ``True`` if the
+      entry is a regular file or a symbolic link pointing to a regular file,
+      return ``False`` if it points to another kind of file, if it doesn't
+      exist anymore or if it is a broken symbolic link.
+
+      If *follow_symlinks* is ``False``, return ``True`` only if this entry
+      is a regular file, return ``False`` if it points to a symbolic link or
+      another kind of file, if it doesn't exist anymore or if it is a broken
+      symbolic link.
+
+      The result is cached in the object. Call :func:`stat.S_ISREG` with
+      :func:`os.stat` to fetch up-to-date information.
+
+      The method can raise :exc:`OSError`, such as :exc:`PermissionError`,
+      but :exc:`FileNotFoundError` is catched.
+
+      In most cases, no system call is required.
+
+   .. method:: is_symlink()
+
+      Return ``True`` if this entry is a symbolic link or a broken symbolic
+      link, return ``False`` if it points to a another kind of file or if the
+      entry doesn't exist anymore.
+
+      The result is cached in the object. Call :func:`os.path.islink` to fetch
+      up-to-date information.
+
+      The method can raise :exc:`OSError`, such as :exc:`PermissionError`,
+      but :exc:`FileNotFoundError` is catched.
+
+      In most cases, no system call is required.
+
+   .. method:: stat(\*, follow_symlinks=True)
+
+      Return a :class:`stat_result` object for this entry. This function
+      normally follows symbolic links; to stat a symbolic link add the
+      argument ``follow_symlinks=False``.
+
+      On Windows, the ``st_ino``, ``st_dev`` and ``st_nlink`` attributes of the
+      :class:`stat_result` are always set to zero. Call :func:`os.stat` to
+      get these attributes.
+
+      The result is cached in the object. Call :func:`os.stat` to fetch
+      up-to-date information.
+
+      On Windows, ``DirEntry.stat(follow_symlinks=False)`` doesn't require a
+      system call. ``DirEntry.stat()`` requires a system call if the entry is a
+      symbolic link.
+
+   .. versionadded:: 3.5
+
+
 .. function:: stat(path, \*, dir_fd=None, follow_symlinks=True)
 
    Get the status of a file or a file descriptor. Perform the equivalent of a
@@ -2044,6 +2262,15 @@ features:
 
       File type.
 
+   On Windows systems, the following attribute is also available:
+
+   .. attribute:: st_file_attributes
+
+      Windows file attributes: ``dwFileAttributes`` member of the
+      ``BY_HANDLE_FILE_INFORMATION`` structure returned by
+      :c:func:`GetFileInformationByHandle`. See the ``FILE_ATTRIBUTE_*``
+      constants in the :mod:`stat` module.
+
    The standard module :mod:`stat` defines functions and constants that are
    useful for extracting information from a :c:type:`stat` structure. (On
    Windows, some items are filled with dummy values.)
@@ -2061,6 +2288,9 @@ features:
       Added the :attr:`st_atime_ns`, :attr:`st_mtime_ns`, and
       :attr:`st_ctime_ns` members.
 
+   .. versionadded:: 3.5
+      Added the :attr:`st_file_attributes` member on Windows.
+
 
 .. function:: stat_float_times([newvalue])
 
@@ -2264,10 +2494,12 @@ features:
 
    This function can support :ref:`specifying a file descriptor <path_fd>`.
 
-   Availability: Unix.
+   Availability: Unix, Windows.
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.5
+      Added support for Windows
 
 .. function:: unlink(path, *, dir_fd=None)
 
@@ -2406,6 +2638,11 @@ features:
           for name in dirs:
               os.rmdir(os.path.join(root, name))
 
+   .. versionchanged:: 3.5
+      The function now calls :func:`os.scandir` instead of :func:`os.listdir`.
+      The usage of :func:`os.scandir` reduces the number of calls to
+      :func:`os.stat`.
+
 
 .. function:: fwalk(top='.', topdown=True, onerror=None, *, follow_symlinks=False, dir_fd=None)
 
@@ -2990,6 +3227,10 @@ written in Python, such as a mail server's external command delivery program.
    doesn't work if it is.  Use the :func:`os.path.normpath` function to ensure that
    the path is properly encoded for Win32.
 
+   To reduce interpreter startup overhead, the Win32 :c:func:`ShellExecute`
+   function is not resolved until this function is first called.  If the function
+   cannot be resolved, :exc:`NotImplementedError` will be raised.
+
    Availability: Windows.
 
 
@@ -3137,6 +3378,11 @@ written in Python, such as a mail server's external command delivery program.
    id is known, not necessarily a child process. The :func:`spawn\* <spawnl>`
    functions called with :const:`P_NOWAIT` return suitable process handles.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: wait3(options)
 
diff --git a/Doc/library/ossaudiodev.rst b/Doc/library/ossaudiodev.rst
index bb5081a..c60d596 100644
--- a/Doc/library/ossaudiodev.rst
+++ b/Doc/library/ossaudiodev.rst
@@ -148,21 +148,30 @@ and (read-only) attributes:
 
 .. 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
+   Write a :term:`bytes-like object` *data* to the audio device and return the
+   number of bytes written.  If the audio device is in blocking mode (the
+   default), the entire data 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`.
 
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 
 .. 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.
+   Write a :term:`bytes-like object` *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.
+
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 
 .. versionchanged:: 3.2
    Audio device objects also support the context management protocol, i.e. they can
diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index 24e2a30..2f06544 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -628,6 +628,17 @@ call fails (for example because the path doesn't exist):
       PosixPath('/home/antoine/pathlib')
 
 
+.. classmethod:: Path.home()
+
+   Return a new path object representing the user's home directory (as
+   returned by :func:`os.path.expanduser` with ``~`` construct)::
+
+      >>> Path.home()
+      PosixPath('/home/antoine')
+
+   .. versionadded:: 3.5
+
+
 .. method:: Path.stat()
 
    Return information about this path (similarly to :func:`os.stat`).
@@ -670,6 +681,18 @@ call fails (for example because the path doesn't exist):
       symlink *points to* an existing file or directory.
 
 
+.. method:: Path.expanduser()
+
+   Return a new path with expanded ``~`` and ``~user`` constructs,
+   as returned by :meth:`os.path.expanduser`::
+
+      >>> p = PosixPath('~/films/Monty Python')
+      >>> p.expanduser()
+      PosixPath('/home/eric/films/Monty Python')
+
+   .. versionadded:: 3.5
+
+
 .. method:: Path.glob(pattern)
 
    Glob the given *pattern* in the directory represented by this path,
@@ -791,7 +814,7 @@ call fails (for example because the path doesn't exist):
    the symbolic link's information rather than its target's.
 
 
-.. method:: Path.mkdir(mode=0o777, parents=False)
+.. method:: Path.mkdir(mode=0o777, parents=False, exist_ok=False)
 
    Create a new directory at this given path.  If *mode* is given, it is
    combined with the process' ``umask`` value to determine the file mode
@@ -805,6 +828,16 @@ call fails (for example because the path doesn't exist):
    If *parents* is false (the default), a missing parent raises
    :exc:`FileNotFoundError`.
 
+   If *exist_ok* is false (the default), an :exc:`FileExistsError` is
+   raised if the target directory already exists.
+
+   If *exist_ok* is true, :exc:`FileExistsError` exceptions will be
+   ignored (same behavior as the POSIX ``mkdir -p`` command), but only if the
+   last path component is not an existing non-directory file.
+
+   .. versionchanged:: 3.5
+      The *exist_ok* parameter was added.
+
 
 .. method:: Path.open(mode='r', buffering=-1, encoding=None, errors=None, newline=None)
 
@@ -824,6 +857,34 @@ call fails (for example because the path doesn't exist):
    if the file's uid isn't found in the system database.
 
 
+.. method:: Path.read_bytes()
+
+   Return the binary contents of the pointed-to file as a bytes object::
+
+      >>> p = Path('my_binary_file')
+      >>> p.write_bytes(b'Binary file contents')
+      20
+      >>> p.read_bytes()
+      b'Binary file contents'
+
+   .. versionadded:: 3.5
+
+
+.. method:: Path.read_text(encoding=None, errors=None)
+
+   Return the decoded contents of the pointed-to file as a string::
+
+      >>> p = Path('my_text_file')
+      >>> p.write_text('Text file contents')
+      18
+      >>> p.read_text()
+      'Text file contents'
+
+   The optional parameters have the same meaning as in :func:`open`.
+
+   .. versionadded:: 3.5
+
+
 .. method:: Path.rename(target)
 
    Rename this file or directory to the given *target*.  *target* can be
@@ -884,6 +945,25 @@ call fails (for example because the path doesn't exist):
    Remove this directory.  The directory must be empty.
 
 
+.. method:: Path.samefile(other_path)
+
+   Return whether this path points to the same file as *other_path*, which
+   can be either a Path object, or a string.  The semantics are similar
+   to :func:`os.path.samefile` and :func:`os.path.samestat`.
+
+   An :exc:`OSError` can be raised if either file cannot be accessed for some
+   reason.
+
+      >>> p = Path('spam')
+      >>> q = Path('eggs')
+      >>> p.samefile(q)
+      False
+      >>> p.samefile('spam')
+      True
+
+   .. versionadded:: 3.5
+
+
 .. method:: Path.symlink_to(target, target_is_directory=False)
 
    Make this path a symbolic link to *target*.  Under Windows,
@@ -917,3 +997,33 @@ call fails (for example because the path doesn't exist):
 
    Remove this file or symbolic link.  If the path points to a directory,
    use :func:`Path.rmdir` instead.
+
+
+.. method:: Path.write_bytes(data)
+
+   Open the file pointed to in bytes mode, write *data* to it, and close the
+   file::
+
+      >>> p = Path('my_binary_file')
+      >>> p.write_bytes(b'Binary file contents')
+      20
+      >>> p.read_bytes()
+      b'Binary file contents'
+
+   An existing file of the same name is overwritten.
+
+   .. versionadded:: 3.5
+
+
+.. method:: Path.write_text(data, encoding=None, errors=None)
+
+   Open the file pointed to in text mode, write *data* to it, and close the
+   file::
+
+      >>> p = Path('my_text_file')
+      >>> p.write_text('Text file contents')
+      18
+      >>> p.read_text()
+      'Text file contents'
+
+   .. versionadded:: 3.5
diff --git a/Doc/library/pickle.rst b/Doc/library/pickle.rst
index 47356f9..4ce4d34 100644
--- a/Doc/library/pickle.rst
+++ b/Doc/library/pickle.rst
@@ -859,7 +859,7 @@ For the simplest code, use the :func:`dump` and :func:`load` functions. ::
    data = {
        'a': [1, 2.0, 3, 4+6j],
        'b': ("character string", b"byte string"),
-       'c': set([None, True, False])
+       'c': {None, True, False}
    }
 
    with open('data.pickle', 'wb') as f:
diff --git a/Doc/library/pkgutil.rst b/Doc/library/pkgutil.rst
index 13ea7b9..5d3295d 100644
--- a/Doc/library/pkgutil.rst
+++ b/Doc/library/pkgutil.rst
@@ -58,7 +58,7 @@ support.
 
    .. deprecated:: 3.3
       This emulation is no longer needed, as the standard import mechanism
-      is now fully PEP 302 compliant and available in :mod:`importlib`
+      is now fully PEP 302 compliant and available in :mod:`importlib`.
 
 
 .. class:: ImpLoader(fullname, file, filename, etc)
@@ -67,7 +67,7 @@ support.
 
    .. deprecated:: 3.3
       This emulation is no longer needed, as the standard import mechanism
-      is now fully PEP 302 compliant and available in :mod:`importlib`
+      is now fully PEP 302 compliant and available in :mod:`importlib`.
 
 
 .. function:: find_loader(fullname)
diff --git a/Doc/library/plistlib.rst b/Doc/library/plistlib.rst
index 2bef120..4165591 100644
--- a/Doc/library/plistlib.rst
+++ b/Doc/library/plistlib.rst
@@ -129,7 +129,7 @@ The following functions are deprecated:
    and binary) file object. Returns the unpacked root object (which usually
    is a dictionary).
 
-   This function calls :func:`load` to do the actual work, the the documentation
+   This function calls :func:`load` to do the actual work, see the documentation
    of :func:`that function <load>` for an explanation of the keyword arguments.
 
    .. note::
diff --git a/Doc/library/pprint.rst b/Doc/library/pprint.rst
index c0589a3..0b44dc8 100644
--- a/Doc/library/pprint.rst
+++ b/Doc/library/pprint.rst
@@ -235,10 +235,10 @@ In its basic form, :func:`pprint` shows the whole object::
              'classifiers': ['Programming Language :: Python :: 2.6',
                              'Programming Language :: Python :: 2.7',
                              'Programming Language :: Python :: 2 :: Only'],
-             'description': 'An extensible framework for Python programming, '
-                            'with special focus\r\n'
-                            'on event-based network programming and '
-                            'multiprotocol integration.',
+             'description': 'An extensible framework for Python programming, with '
+                            'special focus\r\n'
+                            'on event-based network programming and multiprotocol '
+                            'integration.',
              'docs_url': '',
              'download_url': 'UNKNOWN',
              'home_page': 'http://twistedmatrix.com/',
@@ -288,10 +288,10 @@ contents)::
              'cheesecake_documentation_id': None,
              'cheesecake_installability_id': None,
              'classifiers': [...],
-             'description': 'An extensible framework for Python programming, '
-                            'with special focus\r\n'
-                            'on event-based network programming and '
-                            'multiprotocol integration.',
+             'description': 'An extensible framework for Python programming, with '
+                            'special focus\r\n'
+                            'on event-based network programming and multiprotocol '
+                            'integration.',
              'docs_url': '',
              'download_url': 'UNKNOWN',
              'home_page': 'http://twistedmatrix.com/',
@@ -323,13 +323,12 @@ cannot be split, the specified width will be exceeded::
              'cheesecake_installability_id': None,
              'classifiers': [...],
              'description': 'An extensible '
-                            'framework for '
-                            'Python programming, '
-                            'with special '
-                            'focus\r\n'
-                            'on event-based '
-                            'network programming '
-                            'and multiprotocol '
+                            'framework for Python '
+                            'programming, with '
+                            'special focus\r\n'
+                            'on event-based network '
+                            'programming and '
+                            'multiprotocol '
                             'integration.',
              'docs_url': '',
              'download_url': 'UNKNOWN',
@@ -344,8 +343,8 @@ cannot be split, the specified width will be exceeded::
              'release_url': 'http://pypi.python.org/pypi/Twisted/12.3.0',
              'requires_python': None,
              'stable_version': None,
-             'summary': 'An asynchronous '
-                        'networking framework '
-                        'written in Python',
+             'summary': 'An asynchronous networking '
+                        'framework written in '
+                        'Python',
              'version': '12.3.0'},
     'urls': [{...}, {...}]}
diff --git a/Doc/library/py_compile.rst b/Doc/library/py_compile.rst
index bae8450..97f2b20 100644
--- a/Doc/library/py_compile.rst
+++ b/Doc/library/py_compile.rst
@@ -29,9 +29,9 @@ byte-code cache files in the directory containing the source code.
 .. function:: compile(file, cfile=None, dfile=None, doraise=False, optimize=-1)
 
    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 the :PEP:`3147` path, ending in
-   ``.pyc`` (``.pyo`` if optimization is enabled in the current interpreter).
+   The source code is loaded from the file name *file*.  The byte-code is
+   written to *cfile*, which defaults to the :pep:`3147`/:pep:`488` path, ending
+   in ``.pyc``.
    For example, if *file* is ``/foo/bar/baz.py`` *cfile* will default to
    ``/foo/bar/__pycache__/baz.cpython-32.pyc`` for Python 3.2.  If *dfile* is
    specified, it is used as the name of the source file in error messages when
@@ -68,7 +68,7 @@ byte-code cache files in the directory containing the source code.
 .. function:: main(args=None)
 
    Compile several source files.  The files named in *args* (or on the command
-   line, if *args* is ``None``) are compiled and the resulting bytecode is
+   line, if *args* is ``None``) are compiled and the resulting byte-code is
    cached in the normal manner.  This function does not search a directory
    structure to locate source files; it only compiles files named explicitly.
    If ``'-'`` is the only parameter in args, the list of files is taken from
@@ -86,4 +86,3 @@ could not be compiled.
 
    Module :mod:`compileall`
       Utilities to compile all Python source files in a directory tree.
-
diff --git a/Doc/library/queue.rst b/Doc/library/queue.rst
index 680d690..1cb0935 100644
--- a/Doc/library/queue.rst
+++ b/Doc/library/queue.rst
@@ -158,22 +158,32 @@ fully processed by daemon consumer threads.
 
 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.daemon = True
+    def worker():
+        while True:
+            item = q.get()
+            if item is None:
+                break
+            do_work(item)
+            q.task_done()
+
+    q = queue.Queue()
+    threads = []
+    for i in range(num_worker_threads):
+        t = threading.Thread(target=worker)
         t.start()
+        threads.append(t)
 
-   for item in source():
-       q.put(item)
+    for item in source():
+        q.put(item)
 
-   q.join()       # block until all tasks are done
+    # block until all tasks are done
+    q.join()
+
+    # stop workers
+    for i in range(num_worker_threads):
+        q.put(None)
+    for t in threads:
+        t.join()
 
 
 .. seealso::
diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index 11dd367..f8b7727 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -46,8 +46,7 @@ from sources provided by the operating system.
 .. warning::
 
    The pseudo-random generators of this module should not be used for
-   security purposes.  Use :func:`os.urandom` or :class:`SystemRandom` if
-   you require a cryptographically secure pseudo-random number generator.
+   security purposes.
 
 
 Bookkeeping functions:
diff --git a/Doc/library/re.rst b/Doc/library/re.rst
index c3c8b65..8884584 100644
--- a/Doc/library/re.rst
+++ b/Doc/library/re.rst
@@ -281,9 +281,7 @@ The special characters are:
    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.  Group
-   references are not supported even if they match strings of some fixed length.
-   Note 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 not 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:
@@ -299,12 +297,14 @@ The special characters are:
       >>> m.group(0)
       'egg'
 
+   .. versionchanged: 3.5
+      Added support for group references of fixed length.
+
 ``(?<!...)``
    Matches if the current position in the string is not preceded by a match for
    ``...``.  This is called a :dfn:`negative lookbehind assertion`.  Similar to
    positive lookbehind assertions, the contained pattern must only match strings of
-   some fixed length and shouldn't contain group references.
-   Patterns which start with negative lookbehind assertions may
+   some fixed length.  Patterns which start with negative lookbehind assertions may
    match at the beginning of the string being searched.
 
 ``(?(id/name)yes-pattern|no-pattern)``
@@ -438,6 +438,10 @@ three digits in length.
 .. versionchanged:: 3.3
    The ``'\u'`` and ``'\U'`` escape sequences have been added.
 
+.. deprecated-removed:: 3.5 3.6
+   Unknown escapes consist of ``'\'`` and ASCII letter now raise a
+   deprecation warning and will be forbidden in Python 3.6.
+
 
 .. seealso::
 
@@ -524,7 +528,11 @@ form.
    current locale. The use of this flag is discouraged as the locale mechanism
    is very unreliable, and it only handles one "culture" at a time anyway;
    you should use Unicode matching instead, which is the default in Python 3
-   for Unicode (str) patterns.
+   for Unicode (str) patterns. This flag makes sense only with bytes patterns.
+
+   .. deprecated-removed:: 3.5 3.6
+      Deprecated the use of  :const:`re.LOCALE` with string patterns or
+      :const:`re.ASCII`.
 
 
 .. data:: M
@@ -625,17 +633,37 @@ form.
    That way, separator components are always found at the same relative
    indices within the result list.
 
-   Note that *split* will never split a string on an empty pattern match.
-   For example:
+   .. note::
+
+      :func:`split` doesn't currently split a string on an empty pattern match.
+      For example:
 
-      >>> re.split('x*', 'foo')
-      ['foo']
-      >>> re.split("(?m)^$", "foo\n\nbar\n")
-      ['foo\n\nbar\n']
+         >>> re.split('x*', 'axbc')
+         ['a', 'bc']
+
+      Even though ``'x*'`` also matches 0 'x' before 'a', between 'b' and 'c',
+      and after 'c', currently these matches are ignored.  The correct behavior
+      (i.e. splitting on empty matches too and returning ``['', 'a', 'b', 'c',
+      '']``) will be implemented in future versions of Python, but since this
+      is a backward incompatible change, a :exc:`FutureWarning` will be raised
+      in the meanwhile.
+
+      Patterns that can only match empty strings currently never split the
+      string.  Since this doesn't match the expected behavior, a
+      :exc:`ValueError` will be raised starting from Python 3.5::
+
+         >>> re.split("^$", "foo\n\nbar\n", flags=re.M)
+         Traceback (most recent call last):
+           File "<stdin>", line 1, in <module>
+           ...
+         ValueError: split() requires a non-empty pattern match.
 
    .. versionchanged:: 3.1
       Added the optional flags argument.
 
+   .. versionchanged:: 3.5
+      Splitting on a pattern that could match an empty string now raises
+      a warning.  Patterns that can only match empty strings are now rejected.
 
 .. function:: findall(pattern, string, flags=0)
 
@@ -663,7 +691,7 @@ form.
    *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 carriage return, and
-   so forth.  Unknown escapes such as ``\j`` are left alone.  Backreferences, such
+   so forth.  Unknown escapes such as ``\&`` are left alone.  Backreferences, such
    as ``\6``, are replaced with the substring matched by group 6 in the pattern.
    For example:
 
@@ -705,6 +733,13 @@ form.
    .. versionchanged:: 3.1
       Added the optional flags argument.
 
+   .. versionchanged:: 3.5
+      Unmatched groups are replaced with an empty string.
+
+   .. deprecated-removed:: 3.5 3.6
+      Unknown escapes consist of ``'\'`` and ASCII letter now raise a
+      deprecation warning and will be forbidden in Python 3.6.
+
 
 .. function:: subn(pattern, repl, string, count=0, flags=0)
 
@@ -714,6 +749,9 @@ form.
    .. versionchanged:: 3.1
       Added the optional flags argument.
 
+   .. versionchanged:: 3.5
+      Unmatched groups are replaced with an empty string.
+
 
 .. function:: escape(string)
 
@@ -730,13 +768,36 @@ form.
    Clear the regular expression cache.
 
 
-.. exception:: error
+.. exception:: error(msg, pattern=None, pos=None)
 
    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.
+   error if a string contains no match for a pattern.  The error instance has
+   the following additional attributes:
+
+   .. attribute:: msg
+
+      The unformatted error message.
+
+   .. attribute:: pattern
+
+      The regular expression pattern.
+
+   .. attribute:: pos
+
+      The index of *pattern* where compilation failed.
+
+   .. attribute:: lineno
+
+      The line corresponding to *pos*.
+
+   .. attribute:: colno
+
+      The column corresponding to *pos*.
 
+   .. versionchanged:: 3.5
+      Added additional attributes.
 
 .. _re-objects:
 
@@ -889,6 +950,8 @@ Match objects support the following methods and attributes:
    (``\g<1>``, ``\g<name>``) are replaced by the contents of the
    corresponding group.
 
+   .. versionchanged:: 3.5
+      Unmatched groups are replaced with an empty string.
 
 .. method:: match.group([group1, ...])
 
diff --git a/Doc/library/readline.rst b/Doc/library/readline.rst
index 692310b..3864f0d 100644
--- a/Doc/library/readline.rst
+++ b/Doc/library/readline.rst
@@ -59,6 +59,14 @@ The :mod:`readline` module defines the following functions:
    Save a readline history file. The default filename is :file:`~/.history`.
 
 
+.. function:: append_history_file(nelements[, filename])
+
+   Append the last *nelements* of history to a file.  The default filename is
+   :file:`~/.history`.  The file must already exist.
+
+   .. versionadded:: 3.5
+
+
 .. function:: clear_history()
 
    Clear the current history.  (Note: this function is not available if the
@@ -209,6 +217,26 @@ from the user's :envvar:`PYTHONSTARTUP` file. ::
 This code is actually automatically run when Python is run in
 :ref:`interactive mode <tut-interactive>` (see :ref:`rlcompleter-config`).
 
+The following example achieves the same goal but supports concurrent interactive
+sessions, by only appending the new history. ::
+
+   import atexit
+   import os
+   import realine
+   histfile = os.path.join(os.path.expanduser("~"), ".python_history")
+
+   try:
+       readline.read_history_file(histfile)
+       h_len = readline.get_history_length()
+   except FileNotFoundError:
+       open(histfile, 'wb').close()
+       h_len = 0
+
+   def save(prev_h_len, histfile):
+       new_h_len = readline.get_history_length()
+       readline.append_history_file(new_h_len - prev_h_len, histfile)
+   atexit.register(save, h_len, histfile)
+
 The following example extends the :class:`code.InteractiveConsole` class to
 support history save/restore. ::
 
@@ -234,4 +262,3 @@ support history save/restore. ::
 
        def save_history(self, histfile):
            readline.write_history_file(histfile)
-
diff --git a/Doc/library/resource.rst b/Doc/library/resource.rst
index f8112cc..7c0e4ca 100644
--- a/Doc/library/resource.rst
+++ b/Doc/library/resource.rst
@@ -45,7 +45,7 @@ this module for those platforms.
 
 .. data:: RLIM_INFINITY
 
-   Constant used to represent the the limit for an unlimited resource.
+   Constant used to represent the limit for an unlimited resource.
 
 
 .. function:: getrlimit(resource)
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 734e426..a62dc84 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -145,6 +145,13 @@ The module defines the following:
       library, and does not handle file descriptors that don't originate from
       WinSock.
 
+   .. versionchanged:: 3.5
+      The function is now retried with a recomputed timeout when interrupted by
+      a signal, except if the signal handler raises an exception (see
+      :pep:`475` for the rationale), instead of raising
+      :exc:`InterruptedError`.
+
+
 .. attribute:: PIPE_BUF
 
    The minimum number of bytes which can be written without blocking to a pipe
@@ -207,7 +214,7 @@ object.
    .. warning::
 
       Registering a file descriptor that's already registered is not an
-      error, but the result is undefined. The appropiate action is to
+      error, but the result is undefined. The appropriate action is to
       unregister or modify it first. This is an important difference
       compared with :c:func:`poll`.
 
@@ -242,6 +249,12 @@ object.
    returning. If *timeout* is omitted, -1, or :const:`None`, the call will
    block until there is an event for this poll object.
 
+   .. versionchanged:: 3.5
+      The function is now retried with a recomputed timeout when interrupted by
+      a signal, except if the signal handler raises an exception (see
+      :pep:`475` for the rationale), instead of raising
+      :exc:`InterruptedError`.
+
 
 .. _epoll-objects:
 
@@ -322,6 +335,12 @@ Edge and Level Trigger Polling (epoll) Objects
 
    Wait for events. timeout in seconds (float)
 
+   .. versionchanged:: 3.5
+      The function is now retried with a recomputed timeout when interrupted by
+      a signal, except if the signal handler raises an exception (see
+      :pep:`475` for the rationale), instead of raising
+      :exc:`InterruptedError`.
+
 
 .. _poll-objects:
 
@@ -401,6 +420,12 @@ linearly scanned again. :c:func:`select` is O(highest file descriptor), while
    returning. If *timeout* is omitted, negative, or :const:`None`, the call will
    block until there is an event for this poll object.
 
+   .. versionchanged:: 3.5
+      The function is now retried with a recomputed timeout when interrupted by
+      a signal, except if the signal handler raises an exception (see
+      :pep:`475` for the rationale), instead of raising
+      :exc:`InterruptedError`.
+
 
 .. _kqueue-objects:
 
@@ -435,6 +460,12 @@ Kqueue Objects
    - max_events must be 0 or a positive integer
    - timeout in seconds (floats possible)
 
+   .. versionchanged:: 3.5
+      The function is now retried with a recomputed timeout when interrupted by
+      a signal, except if the signal handler raises an exception (see
+      :pep:`475` for the rationale), instead of raising
+      :exc:`InterruptedError`.
+
 
 .. _kevent-objects:
 
diff --git a/Doc/library/selectors.rst b/Doc/library/selectors.rst
index 98377c8..f6ef24b 100644
--- a/Doc/library/selectors.rst
+++ b/Doc/library/selectors.rst
@@ -45,6 +45,7 @@ Classes hierarchy::
    +-- SelectSelector
    +-- PollSelector
    +-- EpollSelector
+   +-- DevpollSelector
    +-- KqueueSelector
 
 
@@ -158,6 +159,12 @@ below:
           timeout has elapsed if the current process receives a signal: in this
           case, an empty list will be returned.
 
+      .. versionchanged:: 3.5
+         The selector is now retried with a recomputed timeout when interrupted
+         by a signal if the signal handler did not raise an exception (see
+         :pep:`475` for the rationale), instead of returning an empty list
+         of events before the timeout.
+
    .. method:: close()
 
       Close the selector.
@@ -207,6 +214,16 @@ below:
       This returns the file descriptor used by the underlying
       :func:`select.epoll` object.
 
+.. class:: DevpollSelector()
+
+   :func:`select.devpoll`-based selector.
+
+   .. method:: fileno()
+
+      This returns the file descriptor used by the underlying
+      :func:`select.devpoll` object.
+
+   .. versionadded:: 3.5
 
 .. class:: KqueueSelector()
 
diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
index cd86e92..3b467e0 100644
--- a/Doc/library/shutil.rst
+++ b/Doc/library/shutil.rst
@@ -191,7 +191,8 @@ Directory and files operations
    match one of the glob-style *patterns* provided.  See the example below.
 
 
-.. function:: copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2, ignore_dangling_symlinks=False)
+.. function:: copytree(src, dst, symlinks=False, ignore=None, \
+              copy_function=copy2, ignore_dangling_symlinks=False)
 
    Recursively copy an entire directory tree rooted at *src*, returning the
    destination directory.  The destination
@@ -282,7 +283,7 @@ Directory and files operations
       .. versionadded:: 3.3
 
 
-.. function:: move(src, dst)
+.. function:: move(src, dst, copy_function=copy2)
 
    Recursively move a file or directory (*src*) to another location (*dst*)
    and return the destination.
@@ -292,15 +293,26 @@ Directory and files operations
    be overwritten depending on :func:`os.rename` semantics.
 
    If the destination is on the current filesystem, then :func:`os.rename` is
-   used.  Otherwise, *src* is copied (using :func:`shutil.copy2`) to *dst* and
-   then removed. In case of symlinks, a new symlink pointing to the target of
-   *src* will be created in or as *dst* and *src* will be removed.
+   used. Otherwise, *src* is copied to *dst* using *copy_function* and then
+   removed.  In case of symlinks, a new symlink pointing to the target of *src*
+   will be created in or as *dst* and *src* will be removed.
+
+   If *copy_function* is given, it must be a callable that takes two arguments
+   *src* and *dst*, and will be used to copy *src* to *dest* if
+   :func:`os.rename` cannot be used.  If the source is a directory,
+   :func:`copytree` is called, passing it the :func:`copy_function`. The
+   default *copy_function* is :func:`copy2`.  Using :func:`copy` as the
+   *copy_function* allows the move to succeed when it is not possible to also
+   copy the metadata, at the expense of not copying any of the metadata.
 
    .. versionchanged:: 3.3
       Added explicit symlink handling for foreign filesystems, thus adapting
       it to the behavior of GNU's :program:`mv`.
       Now returns *dst*.
 
+   .. versionchanged:: 3.5
+      Added the *copy_function* keyword argument.
+
 .. function:: disk_usage(path)
 
    Return disk usage statistics about the given path as a :term:`named tuple`
@@ -338,7 +350,7 @@ Directory and files operations
 
    On Windows, the current directory is always prepended to the *path* whether
    or not you use the default or provide your own, which is the behavior the
-   command shell uses when finding executables.  Additionaly, when finding the
+   command shell uses when finding executables.  Additionally, when finding the
    *cmd* in the *path*, the ``PATHEXT`` environment variable is checked.  For
    example, if you call ``shutil.which("python")``, :func:`which` will search
    ``PATHEXT`` to know that it should look for ``python.exe`` within the *path*
@@ -418,6 +430,26 @@ Another example that uses the *ignore* argument to add a logging call::
    copytree(source, destination, ignore=_logpath)
 
 
+.. _shutil-rmtree-example:
+
+rmtree example
+~~~~~~~~~~~~~~
+
+This example shows how to remove a directory tree on Windows where some
+of the files have their read-only bit set. It uses the onerror callback
+to clear the readonly bit and reattempt the remove. Any subsequent failure
+will propagate. ::
+
+    import os, stat
+    import shutil
+
+    def remove_readonly(func, path, _):
+        "Clear the readonly bit and reattempt the removal"
+        os.chmod(path, stat.S_IWRITE)
+        func(path)
+
+    shutil.rmtree(directory, onerror=remove_readonly)
+
 .. _archiving-operations:
 
 Archiving operations
@@ -434,7 +466,8 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
 
    *base_name* is the name of the file to create, including the path, minus
    any format-specific extension. *format* is the archive format: one of
-   "zip", "tar", "bztar" (if the :mod:`bz2` module is available) or "gztar".
+   "zip", "tar", "bztar" (if the :mod:`bz2` module is available), "xztar"
+   (if the :mod:`lzma` module is available) or "gztar".
 
    *root_dir* is a directory that will be the root directory of the
    archive; for example, we typically chdir into *root_dir* before creating the
@@ -457,6 +490,9 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
 
    The *verbose* argument is unused and deprecated.
 
+   .. versionchanged:: 3.5
+      Added support for the *xztar* format.
+
 
 .. function:: get_archive_formats()
 
@@ -467,6 +503,7 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
 
    - *gztar*: gzip'ed tar-file
    - *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available.)
+   - *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available.)
    - *tar*: uncompressed tar file
    - *zip*: ZIP file
 
@@ -542,6 +579,7 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
 
    - *gztar*: gzip'ed tar-file
    - *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available.)
+   - *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available.)
    - *tar*: uncompressed tar file
    - *zip*: ZIP file
 
diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
index 84e2836..553920d 100644
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -65,6 +65,16 @@ Besides, only the main thread is allowed to set a new signal handler.
 Module contents
 ---------------
 
+.. versionchanged:: 3.5
+   signal (SIG*), handler (:const:`SIG_DFL`, :const:`SIG_IGN`) and sigmask
+   (:const:`SIG_BLOCK`, :const:`SIG_UNBLOCK`, :const:`SIG_SETMASK`)
+   related constants listed below were turned into
+   :class:`enums <enum.IntEnum>`.
+   :func:`getsignal`, :func:`pthread_sigmask`, :func:`sigpending` and
+   :func:`sigwait` functions return human-readable
+   :class:`enums <enum.IntEnum>`.
+
+
 The variables defined in the :mod:`signal` module are:
 
 
@@ -308,6 +318,9 @@ The :mod:`signal` module defines the following functions:
    attempting to call it from other threads will cause a :exc:`ValueError`
    exception to be raised.
 
+   .. versionchanged:: 3.5
+      On Windows, the function now also supports socket handles.
+
 
 .. function:: siginterrupt(signalnum, flag)
 
@@ -395,6 +408,11 @@ The :mod:`signal` module defines the following functions:
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.5
+      The function is now retried if interrupted by a signal not in *sigset*
+      and the signal handler does not raise an exception (see :pep:`475` for
+      the rationale).
+
 
 .. function:: sigtimedwait(sigset, timeout)
 
@@ -409,6 +427,11 @@ The :mod:`signal` module defines the following functions:
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.5
+      The function is now retried with the recomputed *timeout* if interrupted
+      by a signal not in *sigset* and the signal handler does not raise an
+      exception (see :pep:`475` for the rationale).
+
 
 .. _signal-example:
 
diff --git a/Doc/library/site.rst b/Doc/library/site.rst
index e57b8cc..43daf79 100644
--- a/Doc/library/site.rst
+++ b/Doc/library/site.rst
@@ -26,24 +26,23 @@ additions, call the :func:`site.main` function.
    :option:`-S`.
 
 .. 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{X.Y}/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.
+:file:`lib/python{X.Y}/site-packages` (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.
 
-.. deprecated:: 3.4
-   Support for the "site-python" directory will be removed in 3.5.
+.. versionchanged:: 3.5
+   Support for the "site-python" directory has been removed.
 
 If a file named "pyvenv.cfg" exists one directory above sys.executable,
 sys.prefix and sys.exec_prefix are set to that directory and
-it is also checked for site-packages and site-python (sys.base_prefix and
+it is also checked for site-packages (sys.base_prefix and
 sys.base_exec_prefix will always be the "real" prefixes of the Python
 installation). If "pyvenv.cfg" (a bootstrap configuration file) contains
 the key "include-system-site-packages" set to anything other than "false"
@@ -184,7 +183,7 @@ Module contents
    unless the Python interpreter was started with the :option:`-S` flag.
 
    .. versionchanged:: 3.3
-      This function used to be called unconditionnally.
+      This function used to be called unconditionally.
 
 
 .. function:: addsitedir(sitedir, known_paths=None)
@@ -195,8 +194,7 @@ Module contents
 
 .. function:: getsitepackages()
 
-   Return a list containing all global site-packages directories (and possibly
-   site-python).
+   Return a list containing all global site-packages directories.
 
    .. versionadded:: 3.2
 
diff --git a/Doc/library/smtpd.rst b/Doc/library/smtpd.rst
index 3ebed06..3e0c6fb 100644
--- a/Doc/library/smtpd.rst
+++ b/Doc/library/smtpd.rst
@@ -20,7 +20,8 @@ specific mail-sending strategies.
 Additionally the SMTPChannel may be extended to implement very specific
 interaction behaviour with SMTP clients.
 
-The code supports :RFC:`5321`, plus the :rfc:`1870` SIZE extension.
+The code supports :RFC:`5321`, plus the :rfc:`1870` SIZE and :rfc:`6531`
+SMTPUTF8 extensions.
 
 
 SMTPServer Objects
@@ -28,7 +29,7 @@ SMTPServer Objects
 
 
 .. class:: SMTPServer(localaddr, remoteaddr, data_size_limit=33554432,\
-                      map=None)
+                      map=None, enable_SMTPUTF8=False, decode_data=True)
 
    Create a new :class:`SMTPServer` object, which binds to local address
    *localaddr*.  It will treat *remoteaddr* as an upstream SMTP relayer.  It
@@ -39,18 +40,47 @@ SMTPServer Objects
    accepted in a ``DATA`` command.  A value of ``None`` or ``0`` means no
    limit.
 
+   *enable_SMTPUTF8* determins whether the ``SMTPUTF8`` extension (as defined
+   in :RFC:`6531`) should be enabled.  The default is ``False``.  If
+   *enable_SMTPUTF* is set to ``True``, the :meth:`process_smtputf8_message`
+   method must be defined.  A :exc:`ValueError` is raised if both
+   *enable_SMTPUTF8* and *decode_data* are set to ``True`` at the same time.
+
    A dictionary can be specified in *map* to avoid using a global socket map.
 
+   *decode_data* specifies whether the data portion of the SMTP transaction
+   should be decoded using UTF-8.  The default is ``True`` for backward
+   compatibility reasons, but will change to ``False`` in Python 3.6.  Specify
+   the keyword value explicitly to avoid the :exc:`DeprecationWarning`.
+
    .. method:: process_message(peer, mailfrom, rcpttos, data)
 
-      Raise :exc:`NotImplementedError` exception. Override this in subclasses to
+      Raise a :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`
+      containing the contents of the e-mail (which should be in :rfc:`5321`
       format).
 
+      If the *decode_data* constructor keyword is set to ``True``, the *data*
+      argument will be a unicode string.  If it is set to ``False``, it
+      will be a bytes object.
+
+      Return ``None`` to request a normal ``250 Ok`` response; otherwise
+      return the desired response string in :RFC:`5321` format.
+
+   .. method:: process_smtputf8_message(peer, mailfrom, rcpttos, data)
+
+      Raise a :exc:`NotImplementedError` exception.  Override this in
+      subclasses to do something useful with messages when *enable_SMTPUTF8*
+      has been set to ``True`` and the SMTP client requested ``SMTPUTF8``,
+      since this method is called rather than :meth:`process_message` when the
+      client actively requests ``SMTPUTF8``.  The *data* argument will always
+      be a bytes object, and any non-``None`` return value should conform to
+      :rfc:`6531`; otherwise, the API is the same as for
+      :meth:`process_message`.
+
    .. attribute:: channel_class
 
       Override this in subclasses to use a custom :class:`SMTPChannel` for
@@ -59,6 +89,13 @@ SMTPServer Objects
    .. versionchanged:: 3.4
       The *map* argument was added.
 
+   .. versionchanged:: 3.5
+      *localaddr* and *remoteaddr* may now contain IPv6 addresses.
+
+   .. versionadded:: 3.5
+      the *decode_data* and *enable_SMTPUTF8* constructor arguments, and the
+      :meth:`process_smtputf8_message` method.
+
 
 DebuggingServer Objects
 -----------------------
@@ -97,7 +134,7 @@ SMTPChannel Objects
 -------------------
 
 .. class:: SMTPChannel(server, conn, addr, data_size_limit=33554432,\
-                       map=None))
+                       map=None, enable_SMTPUTF8=False, decode_data=True)
 
    Create a new :class:`SMTPChannel` object which manages the communication
    between the server and a single SMTP client.
@@ -108,11 +145,24 @@ SMTPChannel Objects
    accepted in a ``DATA`` command.  A value of ``None`` or ``0`` means no
    limit.
 
+   *enable_SMTPUTF8* determins whether the ``SMTPUTF8`` extension (as defined
+   in :RFC:`6531`) should be enabled.  The default is ``False``.  A
+   :exc:`ValueError` is raised if both *enable_SMTPUTF8* and *decode_data* are
+   set to ``True`` at the same time.
+
    A dictionary can be specified in *map* to avoid using a global socket map.
 
+   *decode_data* specifies whether the data portion of the SMTP transaction
+   should be decoded using UTF-8.  The default is ``True`` for backward
+   compatibility reasons, but will change to ``False`` in Python 3.6.  Specify
+   the keyword value explicitly to avoid the :exc:`DeprecationWarning`.
+
    To use a custom SMTPChannel implementation you need to override the
    :attr:`SMTPServer.channel_class` of your :class:`SMTPServer`.
 
+   .. versionchanged:: 3.5
+      the *decode_data* and *enable_SMTPUTF8* arguments were added.
+
    The :class:`SMTPChannel` has the following instance variables:
 
    .. attribute:: smtp_server
diff --git a/Doc/library/smtplib.rst b/Doc/library/smtplib.rst
index 8e1bfb5..44473fe 100644
--- a/Doc/library/smtplib.rst
+++ b/Doc/library/smtplib.rst
@@ -189,8 +189,12 @@ 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.
+   Set the debug output level.  A value of 1 or ``True`` for *level* results in
+   debug messages for connection and for all messages sent to and received from
+   the server.  A value of 2 for *level* results in these messages being
+   timestamped.
+
+   .. versionchanged:: 3.5 Added debuglevel 2.
 
 
 .. method:: SMTP.docmd(cmd, args='')
@@ -240,8 +244,7 @@ An :class:`SMTP` instance has the following methods:
    the server is stored as the :attr:`ehlo_resp` attribute, :attr:`does_esmtp`
    is set to true or false depending on whether the server supports ESMTP, and
    :attr:`esmtp_features` will be a dictionary containing the names of the
-   SMTP service extensions this server supports, and their
-   parameters (if any).
+   SMTP service extensions this server supports, and their parameters (if any).
 
    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
@@ -291,6 +294,42 @@ An :class:`SMTP` instance has the following methods:
    :exc:`SMTPException`
       No suitable authentication method was found.
 
+   Each of the authentication methods supported by :mod:`smtplib` are tried in
+   turn if they are advertised as supported by the server (see :meth:`auth`
+   for a list of supported authentication methods).
+
+
+.. method:: SMTP.auth(mechanism, authobject)
+
+   Issue an ``SMTP`` ``AUTH`` command for the specified authentication
+   *mechanism*, and handle the challenge response via *authobject*.
+
+   *mechanism* specifies which authentication mechanism is to
+   be used as argument to the ``AUTH`` command; the valid values are
+   those listed in the ``auth`` element of :attr:`esmtp_features`.
+
+   *authobject* must be a callable object taking a single argument:
+
+     data = authobject(challenge)
+
+   It will be called to process the server's challenge response; the
+   *challenge* argument it is passed will be a ``bytes``.  It should return
+   ``bytes`` *data* that will be base64 encoded and sent to the server.
+
+   The ``SMTP`` class provides ``authobjects`` for the ``CRAM-MD5``, ``PLAIN``,
+   and ``LOGIN`` mechanisms; they are named ``SMTP.auth_cram_md5``,
+   ``SMTP.auth_plain``, and ``SMTP.auth_login`` respectively.  They all require
+   that the ``user`` and ``password`` properties of the ``SMTP`` instance are
+   set to appropriate values.
+
+   User code does not normally need to call ``auth`` directly, but can instead
+   call the :meth:`login` method, which will try each of the above mechanisms in
+   turn, in the order listed.  ``auth`` is exposed to facilitate the
+   implementation of authentication methods not (or not yet) supported directly
+   by :mod:`smtplib`.
+
+   .. versionadded:: 3.5
+
 
 .. method:: SMTP.starttls(keyfile=None, certfile=None, context=None)
 
diff --git a/Doc/library/sndhdr.rst b/Doc/library/sndhdr.rst
index f36df68..f8b5d8b 100644
--- a/Doc/library/sndhdr.rst
+++ b/Doc/library/sndhdr.rst
@@ -16,8 +16,9 @@
 
 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*
+what type of sound data is stored in a file, they return a
+:func:`~collections.namedtuple`, containing five attributes: (``filetype``,
+``framerate``, ``nchannels``, ``nframes``, ``sampwidth``). 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
@@ -31,13 +32,19 @@ 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
+   :func:`whathdr`.  If it succeeds, returns a namedtuple as described above, otherwise
    ``None`` is returned.
 
+   .. versionchanged:: 3.5
+      Result changed from a tuple to a namedtuple.
+
 
 .. 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
+   The name of the file is given by *filename*.  This function returns a namedtuple as
    described above on success, or ``None``.
 
+   .. versionchanged:: 3.5
+      Result changed from a tuple to a namedtuple.
+
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index b703e9e..84fa10d 100644
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -46,17 +46,20 @@ created.  Socket addresses are represented as follows:
 - The address of an :const:`AF_UNIX` socket bound to a file system node
   is represented as a string, using the file system encoding and the
   ``'surrogateescape'`` error handler (see :pep:`383`).  An address in
-  Linux's abstract namespace is returned as a :class:`bytes` object with
+  Linux's abstract namespace is returned as a :term:`bytes-like object` with
   an initial null byte; note that sockets in this namespace can
   communicate with normal file system sockets, so programs intended to
   run on Linux may need to deal with both types of address.  A string or
-  :class:`bytes` object can be used for either type of address when
+  bytes-like object can be used for either type of address when
   passing it as an argument.
 
    .. versionchanged:: 3.3
       Previously, :const:`AF_UNIX` socket paths were assumed to use UTF-8
       encoding.
 
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 - 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'``,
@@ -276,6 +279,18 @@ Constants
 
    .. versionadded:: 3.4
 
+.. data:: CAN_RAW_FD_FRAMES
+
+   Enables CAN FD support in a CAN_RAW socket. This is disabled by default.
+   This allows your application to send both CAN and CAN FD frames; however,
+   you one must accept both CAN and CAN FD frames when reading from the socket.
+
+   This constant is documented in the Linux documentation.
+
+   Availability: Linux >= 3.6.
+
+   .. versionadded:: 3.5
+
 .. data:: AF_RDS
           PF_RDS
           SOL_RDS
@@ -352,7 +367,6 @@ The following functions all create :ref:`socket objects <socket-objects>`.
    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.
 
    The newly created sockets are :ref:`non-inheritable <fd_inheritance>`.
 
@@ -363,6 +377,9 @@ The following functions all create :ref:`socket objects <socket-objects>`.
    .. versionchanged:: 3.4
       The returned sockets are now non-inheritable.
 
+   .. versionchanged:: 3.5
+      Windows support added.
+
 
 .. function:: create_connection(address[, timeout[, source_address]])
 
@@ -607,8 +624,8 @@ The :mod:`socket` module also offers various network-related services:
 
 .. function:: inet_ntoa(packed_ip)
 
-   Convert a 32-bit packed IPv4 address (a bytes object four characters in
-   length) to its standard dotted-quad string representation (for example,
+   Convert a 32-bit packed IPv4 address (a :term:`bytes-like object` four
+   bytes 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 :c:type:`struct in_addr`, which
    is the C type for the 32-bit packed binary data this function takes as an
@@ -619,6 +636,9 @@ The :mod:`socket` module also offers various network-related services:
    support IPv6, and :func:`inet_ntop` should be used instead for IPv4/v6 dual
    stack support.
 
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 
 .. function:: inet_pton(address_family, ip_string)
 
@@ -641,22 +661,26 @@ The :mod:`socket` module also offers various network-related services:
 
 .. function:: inet_ntop(address_family, packed_ip)
 
-   Convert a packed IP address (a bytes object 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 :c:type:`struct in_addr` (similar to :func:`inet_ntoa`)
-   or :c:type:`struct in6_addr`.
+   Convert a packed IP address (a :term:`bytes-like object` of some number of
+   bytes) 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 :c:type:`struct in_addr` (similar to :func:`inet_ntoa`) or
+   :c:type:`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:`OSError` is raised for errors from the call to :func:`inet_ntop`.
+   :const:`AF_INET6`. If the bytes object *packed_ip* is not the correct
+   length for the specified address family, :exc:`ValueError` will be raised.
+   A :exc:`OSError` is raised for errors from the call to :func:`inet_ntop`.
 
    Availability: Unix (maybe not all platforms), Windows.
 
    .. versionchanged:: 3.4
       Windows support added
 
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 
 ..
    XXX: Are sendmsg(), recvmsg() and CMSG_*() available on any
@@ -781,6 +805,11 @@ to sockets.
    .. versionchanged:: 3.4
       The socket is now non-inheritable.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.bind(address)
 
@@ -813,6 +842,19 @@ to sockets.
    Connect to a remote socket at *address*. (The format of *address* depends on the
    address family --- see above.)
 
+   If the connection is interrupted by a signal, the method waits until the
+   connection completes, or raise a :exc:`socket.timeout` on timeout, if the
+   signal handler doesn't raise an exception and the socket is blocking or has
+   a timeout. For non-blocking sockets, the method raises an
+   :exc:`InterruptedError` exception if the connection is interrupted by a
+   signal (or the exception raised by the signal handler).
+
+   .. versionchanged:: 3.5
+      The method now waits until the connection completes instead of raising an
+      :exc:`InterruptedError` exception if the connection is interrupted by a
+      signal, the signal handler doesn't raise an exception and the socket is
+      blocking or has a timeout (see the :pep:`475` for the rationale).
+
 
 .. method:: socket.connect_ex(address)
 
@@ -908,12 +950,15 @@ to sockets.
    On other platforms, the generic :func:`fcntl.fcntl` and :func:`fcntl.ioctl`
    functions may be used; they accept a socket object as their first argument.
 
-.. method:: socket.listen(backlog)
+.. 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 0; the maximum value
-   is system-dependent (usually 5), the minimum value is forced to 0.
+   Enable a server to accept connections.  If *backlog* is specified, it must
+   be at least 0 (if it is lower, it is set to 0); it specifies the number of
+   unaccepted connections that the system will allow before refusing new
+   connections. If not specified, a default reasonable value is chosen.
 
+   .. versionchanged:: 3.5
+      The *backlog* parameter is now optional.
 
 .. method:: socket.makefile(mode='r', buffering=None, *, encoding=None, \
                             errors=None, newline=None)
@@ -951,6 +996,11 @@ to sockets.
       For best match with hardware and network realities, the value of  *bufsize*
       should be a relatively small power of 2, for example, 4096.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.recvfrom(bufsize[, flags])
 
@@ -960,6 +1010,11 @@ to sockets.
    :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.)
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.recvmsg(bufsize[, ancbufsize[, flags]])
 
@@ -1026,6 +1081,11 @@ to sockets.
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.recvmsg_into(buffers[, ancbufsize[, flags]])
 
@@ -1092,6 +1152,11 @@ to sockets.
    application needs to attempt delivery of the remaining data. For further
    information on this topic, consult the :ref:`socket-howto`.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.sendall(bytes[, flags])
 
@@ -1102,6 +1167,15 @@ to sockets.
    success.  On error, an exception is raised, and there is no way to determine how
    much data, if any, was successfully sent.
 
+   .. versionchanged:: 3.5
+      The socket timeout is no more reset each time data is sent successfuly.
+      The socket timeout is now the maximum total duration to send all data.
+
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.sendto(bytes, address)
             socket.sendto(bytes, flags, address)
@@ -1112,6 +1186,11 @@ to sockets.
    bytes sent. (The format of *address* depends on the address family --- see
    above.)
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. method:: socket.sendmsg(buffers[, ancdata[, flags[, address]]])
 
@@ -1148,6 +1227,26 @@ to sockets.
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal handler does not raise
+      an exception, the method now retries the system call instead of raising
+      an :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
+.. method:: socket.sendfile(file, offset=0, count=None)
+
+   Send a file until EOF is reached by using high-performance
+   :mod:`os.sendfile` and return the total number of bytes which were sent.
+   *file* must be a regular file object opened in binary mode. If
+   :mod:`os.sendfile` is not available (e.g. Windows) or *file* is not a
+   regular file :meth:`send` will be used instead. *offset* tells from where to
+   start reading the file. If specified, *count* is the total number of bytes
+   to transmit as opposed to sending the file until EOF is reached. File
+   position is updated on return or also in case of error in which case
+   :meth:`file.tell() <io.IOBase.tell>` can be used to figure out the number of
+   bytes which were sent. The socket must be of :const:`SOCK_STREAM` type. Non-
+   blocking sockets are not supported.
+
+   .. versionadded:: 3.5
 
 .. method:: socket.set_inheritable(inheritable)
 
@@ -1187,11 +1286,15 @@ to sockets.
 
    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
-   bytes object representing a buffer.  In the latter case it is up to the caller to
+   :mod:`socket` module (:const:`SO_\*` etc.).  The value can be an integer or
+   a :term:`bytes-like object` representing a buffer.  In the latter case it is
+   up to the caller to
    ensure that the bytestring contains the proper bits (see the optional built-in
    module :mod:`struct` for a way to encode C structures as bytestrings).
 
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 
 .. method:: socket.shutdown(how)
 
@@ -1447,7 +1550,7 @@ After binding (:const:`CAN_RAW`) or connecting (:const:`CAN_BCM`) the socket, yo
 can use the :meth:`socket.send`, and the :meth:`socket.recv` operations (and
 their counterparts) on the socket object as usual.
 
-This example might require special priviledge::
+This example might require special privileges::
 
    import socket
    import struct
diff --git a/Doc/library/socketserver.rst b/Doc/library/socketserver.rst
index 1ec4438..9db36d5 100644
--- a/Doc/library/socketserver.rst
+++ b/Doc/library/socketserver.rst
@@ -113,7 +113,7 @@ the request handler class :meth:`handle` method.
 Another approach to handling multiple simultaneous requests in an environment
 that supports neither threads nor :func:`~os.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.select` to decide which
+partially finished requests and to use :mod:`selectors` 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).  See
@@ -136,7 +136,7 @@ Server Objects
 .. method:: BaseServer.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
+   listening.  This function is most commonly passed to :mod:`selectors`, to
    allow monitoring multiple servers in the same process.
 
 
diff --git a/Doc/library/sqlite3.rst b/Doc/library/sqlite3.rst
index 6097e7a..fc69a80 100644
--- a/Doc/library/sqlite3.rst
+++ b/Doc/library/sqlite3.rst
@@ -649,6 +649,9 @@ Row Objects
       This method returns a list of column names. Immediately after a query,
       it is the first member of each tuple in :attr:`Cursor.description`.
 
+   .. versionchanged:: 3.5
+      Added support of slicing.
+
 Let's assume we initialize a table as in the example given above::
 
    conn = sqlite3.connect(":memory:")
diff --git a/Doc/library/ssl.rst b/Doc/library/ssl.rst
index bc28e97..31b4658 100644
--- a/Doc/library/ssl.rst
+++ b/Doc/library/ssl.rst
@@ -315,6 +315,8 @@ Random generation
 
    For almost all applications :func:`os.urandom` is preferable.
 
+   For almost all applications :func:`os.urandom` is preferable.
+
    .. versionadded:: 3.3
 
 .. function:: RAND_status()
@@ -335,6 +337,8 @@ Random generation
    See http://egd.sourceforge.net/ or http://prngd.sourceforge.net/ for sources
    of entropy-gathering daemons.
 
+   Availability: not available with LibreSSL.
+
 .. function:: RAND_add(bytes, entropy)
 
    Mix the given *bytes* into the SSL pseudo-random number generator.  The
@@ -342,6 +346,9 @@ Random generation
    string (so you can always use :const:`0.0`).  See :rfc:`1750` for more
    information on sources of entropy.
 
+   .. versionchanged: 3.5
+      Writable :term:`bytes-like object` is now accepted.
+
 Certificate handling
 ^^^^^^^^^^^^^^^^^^^^
 
@@ -350,10 +357,9 @@ Certificate handling
    Verify that *cert* (in decoded format as returned by
    :meth:`SSLSocket.getpeercert`) matches the given *hostname*.  The rules
    applied are those for checking the identity of HTTPS servers as outlined
-   in :rfc:`2818` and :rfc:`6125`, except that IP addresses are not currently
-   supported. In addition to HTTPS, this function should be suitable for
-   checking the identity of servers in various SSL-based protocols such as
-   FTPS, IMAPS, POPS and others.
+   in :rfc:`2818` and :rfc:`6125`.  In addition to HTTPS, this function
+   should be suitable for checking the identity of servers in various
+   SSL-based protocols such as FTPS, IMAPS, POPS and others.
 
    :exc:`CertificateError` is raised on failure. On success, the function
    returns nothing::
@@ -375,22 +381,38 @@ Certificate handling
       IDN A-labels such as ``www*.xn--pthon-kva.org`` are still supported,
       but ``x*.python.org`` no longer matches ``xn--tda.python.org``.
 
-.. function:: cert_time_to_seconds(timestring)
+   .. versionchanged:: 3.5
+      Matching of IP addresses, when present in the subjectAltName field
+      of the certificate, is now supported.
+
+.. function:: cert_time_to_seconds(cert_time)
 
-   Returns a floating-point value containing a normal seconds-after-the-epoch
-   time value, given the time-string representing the "notBefore" or "notAfter"
-   date from a certificate.
+   Return the time in seconds since the Epoch, given the ``cert_time``
+   string representing the "notBefore" or "notAfter" date from a
+   certificate in ``"%b %d %H:%M:%S %Y %Z"`` strptime format (C
+   locale).
 
-   Here's an example::
+   Here's an example:
 
-     >>> import ssl
-     >>> ssl.cert_time_to_seconds("May  9 00:00:00 2007 GMT")
-     1178694000.0
-     >>> import time
-     >>> time.ctime(ssl.cert_time_to_seconds("May  9 00:00:00 2007 GMT"))
-     'Wed May  9 00:00:00 2007'
+   .. doctest:: newcontext
 
-.. function:: get_server_certificate(addr, ssl_version=PROTOCOL_SSLv3, ca_certs=None)
+      >>> import ssl
+      >>> timestamp = ssl.cert_time_to_seconds("Jan  5 09:34:43 2018 GMT")
+      >>> timestamp
+      1515144883
+      >>> from datetime import datetime
+      >>> print(datetime.utcfromtimestamp(timestamp))
+      2018-01-05 09:34:43
+
+   "notBefore" or "notAfter" dates must use GMT (:rfc:`5280`).
+
+   .. versionchanged:: 3.5
+      Interpret the input time as a time in UTC as specified by 'GMT'
+      timezone in the input string. Local timezone was used
+      previously. Return an integer (no fractions of a second in the
+      input format)
+
+.. function:: get_server_certificate(addr, ssl_version=PROTOCOL_SSLv23, ca_certs=None)
 
    Given the address ``addr`` of an SSL-protected server, as a (*hostname*,
    *port-number*) pair, fetches the server's certificate, and returns it as a
@@ -404,6 +426,10 @@ Certificate handling
    .. versionchanged:: 3.3
       This function is now IPv6-compatible.
 
+   .. versionchanged:: 3.5
+      The default *ssl_version* is changed from :data:`PROTOCOL_SSLv3` to
+      :data:`PROTOCOL_SSLv23` for maximum compatibility with modern servers.
+
 .. function:: DER_cert_to_PEM_cert(DER_cert_bytes)
 
    Given a certificate as a DER-encoded blob of bytes, returns a PEM-encoded
@@ -671,6 +697,13 @@ Constants
 
    .. versionadded:: 3.3
 
+.. data:: HAS_ALPN
+
+   Whether the OpenSSL library has built-in support for the *Application-Layer
+   Protocol Negotiation* TLS extension as described in :rfc:`7301`.
+
+   .. versionadded:: 3.5
+
 .. data:: HAS_ECDH
 
    Whether the OpenSSL library has built-in support for Elliptic Curve-based
@@ -788,6 +821,8 @@ SSL Sockets
      (but passing a non-zero ``flags`` argument is not allowed)
    - :meth:`~socket.socket.send()`, :meth:`~socket.socket.sendall()` (with
      the same limitation)
+   - :meth:`~socket.socket.sendfile()` (but :mod:`os.sendfile` will be used
+     for plain-text sockets only, else :meth:`~socket.socket.send()` will be used)
    - :meth:`~socket.socket.shutdown()`
 
    However, since the SSL (and TLS) protocol has its own framing atop
@@ -798,6 +833,15 @@ SSL Sockets
    Usually, :class:`SSLSocket` are not created directly, but using the
    :func:`wrap_socket` function or the :meth:`SSLContext.wrap_socket` method.
 
+   .. versionchanged:: 3.5
+      The :meth:`sendfile` method was added.
+
+   .. versionchanged:: 3.5
+      The :meth:`shutdown` does not reset the socket timeout each time bytes
+      are received or sent. The socket timeout is now to maximum total duration
+      of the shutdown.
+
+
 SSL sockets also have the following additional methods and attributes:
 
 .. method:: SSLSocket.read(len=0, buffer=None)
@@ -812,6 +856,11 @@ SSL sockets also have the following additional methods and attributes:
    As at any time a re-negotiation is possible, a call to :meth:`read` can also
    cause write operations.
 
+   .. versionchanged:: 3.5
+      The socket timeout is no more reset each time bytes are received or sent.
+      The socket timeout is now to maximum total duration to read up to *len*
+      bytes.
+
 .. method:: SSLSocket.write(buf)
 
    Write *buf* to the SSL socket and return the number of bytes written. The
@@ -823,6 +872,10 @@ SSL sockets also have the following additional methods and attributes:
    As at any time a re-negotiation is possible, a call to :meth:`write` can
    also cause read operations.
 
+   .. versionchanged:: 3.5
+      The socket timeout is no more reset each time bytes are received or sent.
+      The socket timeout is now to maximum total duration to write *buf*.
+
 .. note::
 
    The :meth:`~SSLSocket.read` and :meth:`~SSLSocket.write` methods are the
@@ -844,6 +897,10 @@ SSL sockets also have the following additional methods and attributes:
       :attr:`~SSLContext.check_hostname` attribute of the socket's
       :attr:`~SSLSocket.context` is true.
 
+   .. versionchanged:: 3.5
+      The socket timeout is no more reset each time bytes are received or sent.
+      The socket timeout is now to maximum total duration of the handshake.
+
 .. method:: SSLSocket.getpeercert(binary_form=False)
 
    If there is no certificate for the peer on the other end of the connection,
@@ -917,6 +974,17 @@ SSL sockets also have the following additional methods and attributes:
    version of the SSL protocol that defines its use, and the number of secret
    bits being used.  If no connection has been established, returns ``None``.
 
+.. method:: SSLSocket.shared_ciphers()
+
+   Return the list of ciphers shared by the client during the handshake.  Each
+   entry of the returned list is a three-value tuple containing the name of the
+   cipher, the version of the SSL protocol that defines its use, and the number
+   of secret bits the cipher uses.  :meth:`~SSLSocket.shared_ciphers` returns
+   ``None`` if no connection has been established or the socket is a client
+   socket.
+
+   .. versionadded:: 3.5
+
 .. method:: SSLSocket.compression()
 
    Return the compression algorithm being used as a string, or ``None``
@@ -940,12 +1008,22 @@ SSL sockets also have the following additional methods and attributes:
 
    .. versionadded:: 3.3
 
+.. method:: SSLSocket.selected_alpn_protocol()
+
+   Return the protocol that was selected during the TLS handshake.  If
+   :meth:`SSLContext.set_alpn_protocols` was not called, if the other party does
+   not support ALPN, if this socket does not support any of the client's
+   proposed protocols, or if the handshake has not happened yet, ``None`` is
+   returned.
+
+   .. versionadded:: 3.5
+
 .. method:: SSLSocket.selected_npn_protocol()
 
-   Returns the protocol that was selected during the TLS/SSL handshake. If
-   :meth:`SSLContext.set_npn_protocols` was not called, or if the other party
-   does not support NPN, or if the handshake has not yet happened, this will
-   return ``None``.
+   Return the higher-level protocol that was selected during the TLS/SSL
+   handshake. If :meth:`SSLContext.set_npn_protocols` was not called, or
+   if the other party does not support NPN, or if the handshake has not yet
+   happened, this will return ``None``.
 
    .. versionadded:: 3.3
 
@@ -957,6 +1035,16 @@ SSL sockets also have the following additional methods and attributes:
    returned socket should always be used for further communication with the
    other side of the connection, rather than the original socket.
 
+.. method:: SSLSocket.version()
+
+   Return the actual SSL protocol version negotiated by the connection
+   as a string, or ``None`` is no secure connection is established.
+   As of this writing, possible return values include ``"SSLv2"``,
+   ``"SSLv3"``, ``"TLSv1"``, ``"TLSv1.1"`` and ``"TLSv1.2"``.
+   Recent OpenSSL versions may define more return values.
+
+   .. versionadded:: 3.5
+
 .. method:: SSLSocket.pending()
 
    Returns the number of already decrypted bytes available for read, pending on
@@ -1135,6 +1223,20 @@ to speed up repeated connections from the same clients.
       when connected, the :meth:`SSLSocket.cipher` method of SSL sockets will
       give the currently selected cipher.
 
+.. method:: SSLContext.set_alpn_protocols(protocols)
+
+   Specify which protocols the socket should advertise during the SSL/TLS
+   handshake. It should be a list of ASCII strings, like ``['http/1.1',
+   'spdy/2']``, ordered by preference. The selection of a protocol will happen
+   during the handshake, and will play out according to :rfc:`7301`. After a
+   successful handshake, the :meth:`SSLSocket.selected_alpn_protocol` method will
+   return the agreed-upon protocol.
+
+   This method will raise :exc:`NotImplementedError` if :data:`HAS_ALPN` is
+   False.
+
+   .. versionadded:: 3.5
+
 .. method:: SSLContext.set_npn_protocols(protocols)
 
    Specify which protocols the socket should advertise during the SSL/TLS
@@ -1175,7 +1277,7 @@ to speed up repeated connections from the same clients.
 
    Due to the early negotiation phase of the TLS connection, only limited
    methods and attributes are usable like
-   :meth:`SSLSocket.selected_npn_protocol` and :attr:`SSLSocket.context`.
+   :meth:`SSLSocket.selected_alpn_protocol` and :attr:`SSLSocket.context`.
    :meth:`SSLSocket.getpeercert`, :meth:`SSLSocket.getpeercert`,
    :meth:`SSLSocket.cipher` and :meth:`SSLSocket.compress` methods require that
    the TLS connection has progressed beyond the TLS Client Hello and therefore
@@ -1251,10 +1353,20 @@ to speed up repeated connections from the same clients.
    quite similarly to HTTP virtual hosts. Specifying *server_hostname* will
    raise a :exc:`ValueError` if *server_side* is true.
 
-   .. versionchanged:: 3.4.3
+   .. versionchanged:: 3.5
       Always allow a server_hostname to be passed, even if OpenSSL does not
       have SNI.
 
+.. method:: SSLContext.wrap_bio(incoming, outgoing, server_side=False, \
+                                server_hostname=None)
+
+   Create a new :class:`SSLObject` instance by wrapping the BIO objects
+   *incoming* and *outgoing*. The SSL routines will read input data from the
+   incoming BIO and write data to the outgoing BIO.
+
+   The *server_side* and *server_hostname* parameters have the same meaning as
+   in :meth:`SSLContext.wrap_socket`.
+
 .. method:: SSLContext.session_stats()
 
    Get statistics about the SSL sessions created or managed by this context.
@@ -1627,7 +1739,7 @@ are finished with the client (or the client is finished with you)::
 
 And go back to listening for new client connections (of course, a real server
 would probably handle each client connection in a separate thread, or put
-the sockets in non-blocking mode and use an event loop).
+the sockets in :ref:`non-blocking mode <ssl-nonblocking>` and use an event loop).
 
 
 .. _ssl-nonblocking:
@@ -1649,6 +1761,12 @@ thus several things you need to be aware of:
   socket first, and attempts to *read* from the SSL socket may require
   a prior *write* to the underlying socket.
 
+  .. versionchanged:: 3.5
+
+     In earlier Python versions, the :meth:`!SSLSocket.send` method
+     returned zero instead of raising :exc:`SSLWantWriteError` or
+     :exc:`SSLWantReadError`.
+
 - Calling :func:`~select.select` tells you that the OS-level socket can be
   read from (or written to), but it does not imply that there is sufficient
   data at the upper SSL layer.  For example, only part of an SSL frame might
@@ -1681,13 +1799,143 @@ thus several things you need to be aware of:
 
 .. seealso::
 
-   The :mod:`asyncio` module supports non-blocking SSL sockets and provides a
+   The :mod:`asyncio` module supports :ref:`non-blocking SSL sockets
+   <ssl-nonblocking>` and provides a
    higher level API. It polls for events using the :mod:`selectors` module and
    handles :exc:`SSLWantWriteError`, :exc:`SSLWantReadError` and
    :exc:`BlockingIOError` exceptions. It runs the SSL handshake asynchronously
    as well.
 
 
+Memory BIO Support
+------------------
+
+.. versionadded:: 3.5
+
+Ever since the SSL module was introduced in Python 2.6, the :class:`SSLSocket`
+class has provided two related but distinct areas of functionality:
+
+- SSL protocol handling
+- Network IO
+
+The network IO API is identical to that provided by :class:`socket.socket`,
+from which :class:`SSLSocket` also inherits. This allows an SSL socket to be
+used as a drop-in replacement for a regular socket, making it very easy to add
+SSL support to an existing application.
+
+Combining SSL protocol handling and network IO usually works well, but there
+are some cases where it doesn't. An example is async IO frameworks that want to
+use a different IO multiplexing model than the "select/poll on a file
+descriptor" (readiness based) model that is assumed by :class:`socket.socket`
+and by the internal OpenSSL socket IO routines. This is mostly relevant for
+platforms like Windows where this model is not efficient. For this purpose, a
+reduced scope variant of :class:`SSLSocket` called :class:`SSLObject` is
+provided.
+
+.. class:: SSLObject
+
+   A reduced-scope variant of :class:`SSLSocket` representing an SSL protocol
+   instance that does not contain any network IO methods. This class is
+   typically used by framework authors that want to implement asynchronous IO
+   for SSL through memory buffers.
+
+   This class implements an interface on top of a low-level SSL object as
+   implemented by OpenSSL. This object captures the state of an SSL connection
+   but does not provide any network IO itself. IO needs to be performed through
+   separate "BIO" objects which are OpenSSL's IO abstraction layer.
+
+   An :class:`SSLObject` instance can be created using the
+   :meth:`~SSLContext.wrap_bio` method. This method will create the
+   :class:`SSLObject` instance and bind it to a pair of BIOs. The *incoming*
+   BIO is used to pass data from Python to the SSL protocol instance, while the
+   *outgoing* BIO is used to pass data the other way around.
+
+   The following methods are available:
+
+   - :attr:`~SSLSocket.context`
+   - :attr:`~SSLSocket.server_side`
+   - :attr:`~SSLSocket.server_hostname`
+   - :meth:`~SSLSocket.read`
+   - :meth:`~SSLSocket.write`
+   - :meth:`~SSLSocket.getpeercert`
+   - :meth:`~SSLSocket.selected_npn_protocol`
+   - :meth:`~SSLSocket.cipher`
+   - :meth:`~SSLSocket.shared_ciphers`
+   - :meth:`~SSLSocket.compression`
+   - :meth:`~SSLSocket.pending`
+   - :meth:`~SSLSocket.do_handshake`
+   - :meth:`~SSLSocket.unwrap`
+   - :meth:`~SSLSocket.get_channel_binding`
+
+   When compared to :class:`SSLSocket`, this object lacks the following
+   features:
+
+   - Any form of network IO incluging methods such as ``recv()`` and
+     ``send()``.
+
+   - There is no *do_handshake_on_connect* machinery. You must always manually
+     call :meth:`~SSLSocket.do_handshake` to start the handshake.
+
+   - There is no handling of *suppress_ragged_eofs*. All end-of-file conditions
+     that are in violation of the protocol are reported via the
+     :exc:`SSLEOFError` exception.
+
+   - The method :meth:`~SSLSocket.unwrap` call does not return anything,
+     unlike for an SSL socket where it returns the underlying socket.
+
+   - The *server_name_callback* callback passed to
+     :meth:`SSLContext.set_servername_callback` will get an :class:`SSLObject`
+     instance instead of a :class:`SSLSocket` instance as its first parameter.
+
+   Some notes related to the use of :class:`SSLObject`:
+
+   - All IO on an :class:`SSLObject` is :ref:`non-blocking <ssl-nonblocking>`.
+     This means that for example :meth:`~SSLSocket.read` will raise an
+     :exc:`SSLWantReadError` if it needs more data than the incoming BIO has
+     available.
+
+   - There is no module-level ``wrap_bio()`` call like there is for
+     :meth:`~SSLContext.wrap_socket`. An :class:`SSLObject` is always created
+     via an :class:`SSLContext`.
+
+An SSLObject communicates with the outside world using memory buffers. The
+class :class:`MemoryBIO` provides a memory buffer that can be used for this
+purpose.  It wraps an OpenSSL memory BIO (Basic IO) object:
+
+.. class:: MemoryBIO
+
+   A memory buffer that can be used to pass data between Python and an SSL
+   protocol instance.
+
+   .. attribute:: MemoryBIO.pending
+
+      Return the number of bytes currently in the memory buffer.
+
+   .. attribute:: MemoryBIO.eof
+
+      A boolean indicating whether the memory BIO is current at the end-of-file
+      position.
+
+   .. method:: MemoryBIO.read(n=-1)
+
+      Read up to *n* bytes from the memory buffer. If *n* is not specified or
+      negative, all bytes are returned.
+
+   .. method:: MemoryBIO.write(buf)
+
+      Write the bytes from *buf* to the memory BIO. The *buf* argument must be an
+      object supporting the buffer protocol.
+
+      The return value is the number of bytes written, which is always equal to
+      the length of *buf*.
+
+   .. method:: MemoryBIO.write_eof()
+
+      Write an EOF marker to the memory BIO. After this method has been called, it
+      is illegal to call :meth:`~MemoryBIO.write`. The attribute :attr:`eof` will
+      become true after all data currently in the buffer has been read.
+
+
 .. _ssl-security:
 
 Security considerations
diff --git a/Doc/library/stat.rst b/Doc/library/stat.rst
index 24769f6..845b2ef 100644
--- a/Doc/library/stat.rst
+++ b/Doc/library/stat.rst
@@ -126,7 +126,7 @@ Example::
    if __name__ == '__main__':
        walktree(sys.argv[1], visitfile)
 
-An additional utility function is provided to covert a file's mode in a human
+An additional utility function is provided to convert a file's mode in a human
 readable string:
 
 .. function:: filemode(mode)
@@ -399,3 +399,29 @@ The following flags can be used in the *flags* argument of :func:`os.chflags`:
    The file is a snapshot file.
 
 See the \*BSD or Mac OS systems man page :manpage:`chflags(2)` for more information.
+
+On Windows, the following file attribute constants are available for use when
+testing bits in the ``st_file_attributes`` member returned by :func:`os.stat`.
+See the `Windows API documentation
+<http://msdn.microsoft.com/en-us/library/windows/desktop/gg258117.aspx>`_
+for more detail on the meaning of these constants.
+
+.. data:: FILE_ATTRIBUTE_ARCHIVE
+          FILE_ATTRIBUTE_COMPRESSED
+          FILE_ATTRIBUTE_DEVICE
+          FILE_ATTRIBUTE_DIRECTORY
+          FILE_ATTRIBUTE_ENCRYPTED
+          FILE_ATTRIBUTE_HIDDEN
+          FILE_ATTRIBUTE_INTEGRITY_STREAM
+          FILE_ATTRIBUTE_NORMAL
+          FILE_ATTRIBUTE_NOT_CONTENT_INDEXED
+          FILE_ATTRIBUTE_NO_SCRUB_DATA
+          FILE_ATTRIBUTE_OFFLINE
+          FILE_ATTRIBUTE_READONLY
+          FILE_ATTRIBUTE_REPARSE_POINT
+          FILE_ATTRIBUTE_SPARSE_FILE
+          FILE_ATTRIBUTE_SYSTEM
+          FILE_ATTRIBUTE_TEMPORARY
+          FILE_ATTRIBUTE_VIRTUAL
+
+   .. versionadded:: 3.5
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index a4324b5..26ff309 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -354,7 +354,7 @@ Notes:
    The numeric literals accepted include the digits ``0`` to ``9`` or any
    Unicode equivalent (code points with the ``Nd`` property).
 
-   See http://www.unicode.org/Public/6.3.0/ucd/extracted/DerivedNumericType.txt
+   See http://www.unicode.org/Public/7.0.0/ucd/extracted/DerivedNumericType.txt
    for a complete list of code points with the ``Nd`` property.
 
 
@@ -3089,6 +3089,203 @@ place, and instead produce new objects.
       always produces a new object, even if no changes were made.
 
 
+.. _bytes-formatting:
+
+``printf``-style Bytes Formatting
+----------------------------------
+
+.. index::
+   single: formatting, bytes (%)
+   single: formatting, bytearray (%)
+   single: interpolation, bytes (%)
+   single: interpolation, bytearray (%)
+   single: bytes; formatting
+   single: bytearray; formatting
+   single: bytes; interpolation
+   single: bytearray; interpolation
+   single: printf-style formatting
+   single: sprintf-style formatting
+   single: % formatting
+   single: % interpolation
+
+.. note::
+
+   The formatting operations described here exhibit a variety of quirks that
+   lead to a number of common errors (such as failing to display tuples and
+   dictionaries correctly).  If the value being printed may be a tuple or
+   dictionary, wrap it in a tuple.
+
+Bytes objects (``bytes``/``bytearray``) have one unique built-in operation:
+the ``%`` operator (modulo).
+This is also known as the bytes *formatting* or *interpolation* operator.
+Given ``format % values`` (where *format* is a bytes object), ``%`` conversion
+specifications in *format* are replaced with zero or more elements of *values*.
+The effect is similar to using the :c:func:`sprintf` in the C language.
+
+If *format* requires a single argument, *values* may be a single non-tuple
+object. [5]_  Otherwise, *values* must be a tuple with exactly the number of
+items specified by the format bytes object, 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 precision 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 bytes object *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(b'%(language)s has %(number)03d quote types.' %
+   ...       {b'language': b"Python", b"number": 2})
+   b'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 -- so e.g. ``%ld`` is identical to ``%d``.
+
+The conversion types are:
+
++------------+-----------------------------------------------------+-------+
+| Conversion | Meaning                                             | Notes |
++============+=====================================================+=======+
+| ``'d'``    | Signed integer decimal.                             |       |
++------------+-----------------------------------------------------+-------+
+| ``'i'``    | Signed integer decimal.                             |       |
++------------+-----------------------------------------------------+-------+
+| ``'o'``    | Signed octal value.                                 | \(1)  |
++------------+-----------------------------------------------------+-------+
+| ``'u'``    | Obsolete type -- it is identical to ``'d'``.        | \(8)  |
++------------+-----------------------------------------------------+-------+
+| ``'x'``    | Signed hexadecimal (lowercase).                     | \(2)  |
++------------+-----------------------------------------------------+-------+
+| ``'X'``    | Signed 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 lowercase exponential   | \(4)  |
+|            | format if exponent is less than -4 or not less than |       |
+|            | precision, decimal format otherwise.                |       |
++------------+-----------------------------------------------------+-------+
+| ``'G'``    | Floating point format. Uses uppercase exponential   | \(4)  |
+|            | format if exponent is less than -4 or not less than |       |
+|            | precision, decimal format otherwise.                |       |
++------------+-----------------------------------------------------+-------+
+| ``'c'``    | Single byte (accepts integer or single              |       |
+|            | byte objects).                                      |       |
++------------+-----------------------------------------------------+-------+
+| ``'b'``    | Bytes (any object that follows the                  | \(5)  |
+|            | :ref:`buffer protocol <bufferobjects>` or has       |       |
+|            | :meth:`__bytes__`).                                 |       |
++------------+-----------------------------------------------------+-------+
+| ``'s'``    | ``'s'`` is an alias for ``'b'`` and should only     | \(6)  |
+|            | be used for Python2/3 code bases.                   |       |
++------------+-----------------------------------------------------+-------+
+| ``'a'``    | Bytes (converts any Python object using             | \(5)  |
+|            | ``repr(obj).encode('ascii','backslashreplace)``).   |       |
++------------+-----------------------------------------------------+-------+
+| ``'r'``    | ``'r'`` is an alias for ``'a'`` and should only     | \(7)  |
+|            | be used for Python2/3 code bases.                   |       |
++------------+-----------------------------------------------------+-------+
+| ``'%'``    | 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)
+   If precision is ``N``, the output is truncated to ``N`` characters.
+
+(6)
+   ``b'%s'`` is deprecated, but will not be removed during the 3.x series.
+
+(7)
+   ``b'%r'`` is deprecated, but will not be removed during the 3.x series.
+
+(8)
+   See :pep:`237`.
+
+.. note::
+
+   The bytearray version of this method does *not* operate in place - it
+   always produces a new object, even if no changes were made.
+
+.. seealso:: :pep:`461`.
+.. versionadded:: 3.5
+
 .. _typememoryview:
 
 Memory Views
@@ -3117,10 +3314,8 @@ copying.
    the view. The :class:`~memoryview.itemsize` attribute will give you the
    number of bytes in a single element.
 
-   A :class:`memoryview` supports slicing to expose its data. If
-   :class:`~memoryview.format` is one of the native format specifiers
-   from the :mod:`struct` module, indexing will return a single element
-   with the correct type. Full slicing will result in a subview::
+   A :class:`memoryview` supports slicing and indexing to expose its data.
+   One-dimensional slicing will result in a subview::
 
     >>> v = memoryview(b'abcefg')
     >>> v[1]
@@ -3132,25 +3327,29 @@ copying.
     >>> bytes(v[1:4])
     b'bce'
 
-   Other native formats::
+   If :class:`~memoryview.format` is one of the native format specifiers
+   from the :mod:`struct` module, indexing with an integer or a tuple of
+   integers is also supported and returns a single *element* with
+   the correct type.  One-dimensional memoryviews can be indexed
+   with an integer or a one-integer tuple.  Multi-dimensional memoryviews
+   can be indexed with tuples of exactly *ndim* integers where *ndim* is
+   the number of dimensions.  Zero-dimensional memoryviews can be indexed
+   with the empty tuple.
+
+   Here is an example with a non-byte format::
 
       >>> import array
       >>> a = array.array('l', [-11111111, 22222222, -33333333, 44444444])
-      >>> a[0]
+      >>> m = memoryview(a)
+      >>> m[0]
       -11111111
-      >>> a[-1]
+      >>> m[-1]
       44444444
-      >>> a[2:3].tolist()
-      [-33333333]
-      >>> a[::2].tolist()
+      >>> m[::2].tolist()
       [-11111111, -33333333]
-      >>> a[::-1].tolist()
-      [44444444, -33333333, 22222222, -11111111]
 
-   .. versionadded:: 3.3
-
-   If the underlying object is writable, the memoryview supports slice
-   assignment. Resizing is not allowed::
+   If the underlying object is writable, the memoryview supports
+   one-dimensional slice assignment. Resizing is not allowed::
 
       >>> data = bytearray(b'abcefg')
       >>> v = memoryview(data)
@@ -3183,12 +3382,16 @@ copying.
       True
 
    .. versionchanged:: 3.3
+      One-dimensional memoryviews can now be sliced.
       One-dimensional memoryviews with formats 'B', 'b' or 'c' are now hashable.
 
    .. versionchanged:: 3.4
       memoryview is now registered automatically with
       :class:`collections.abc.Sequence`
 
+   .. versionchanged:: 3.5
+      memoryviews can now be indexed with tuple of integers.
+
    :class:`memoryview` has several methods:
 
    .. method:: __eq__(exporter)
diff --git a/Doc/library/string.rst b/Doc/library/string.rst
index f9da5fa..eab9f37 100644
--- a/Doc/library/string.rst
+++ b/Doc/library/string.rst
@@ -95,6 +95,10 @@ implementation as the built-in :meth:`format` method.
       an arbitrary set of positional and keyword arguments.
       :meth:`format` is just a wrapper that calls :meth:`vformat`.
 
+      .. deprecated:: 3.5
+         Passing a format string as keyword argument *format_string* has been
+         deprecated.
+
    .. method:: vformat(format_string, args, kwargs)
 
       This function does the actual work of formatting.  It is exposed as a
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 36cbf3c..9a2f4de 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -25,160 +25,99 @@ modules and functions can be found in the following sections.
 Using the :mod:`subprocess` Module
 ----------------------------------
 
-The recommended approach to invoking subprocesses is to use the following
-convenience functions for all use cases they can handle. For more advanced
-use cases, the underlying :class:`Popen` interface can be used directly.
+The recommended approach to invoking subprocesses is to use the :func:`run`
+function for all use cases it can handle. For more advanced use cases, the
+underlying :class:`Popen` interface can be used directly.
 
+The :func:`run` function was added in Python 3.5; if you need to retain
+compatibility with older versions, see the :ref:`call-function-trio` section.
 
-.. function:: call(args, *, stdin=None, stdout=None, stderr=None, shell=False, timeout=None)
+
+.. function:: run(args, *, stdin=None, input=None, stdout=None, stderr=None,\
+                  shell=False, timeout=None, check=False)
 
    Run the command described by *args*.  Wait for command to complete, then
-   return the :attr:`returncode` attribute.
+   return a :class:`CompletedProcess` instance.
 
    The arguments shown above are merely the most common ones, described below
    in :ref:`frequently-used-arguments` (hence the use of keyword-only notation
    in the abbreviated signature). The full function signature is largely the
-   same as that of the :class:`Popen` constructor - this function passes all
-   supplied arguments other than *timeout* directly through to that interface.
+   same as that of the :class:`Popen` constructor - apart from *timeout*,
+   *input* and *check*, all the arguments to this function are passed through to
+   that interface.
 
-   The *timeout* argument is passed to :meth:`Popen.wait`. If the timeout
-   expires, the child process will be killed and then waited for again.  The
+   This does not capture stdout or stderr by default. To do so, pass
+   :data:`PIPE` for the *stdout* and/or *stderr* arguments.
+
+   The *timeout* argument is passed to :meth:`Popen.communicate`. If the timeout
+   expires, the child process will be killed and waited for.  The
    :exc:`TimeoutExpired` exception will be re-raised after the child process
    has terminated.
 
-   Examples::
-
-      >>> subprocess.call(["ls", "-l"])
-      0
-
-      >>> subprocess.call("exit 1", shell=True)
-      1
-
-   .. note::
-
-      Do not use ``stdout=PIPE`` or ``stderr=PIPE`` with this
-      function.  The child process will block if it generates enough
-      output to a pipe to fill up the OS pipe buffer as the pipes are
-      not being read from.
-
-   .. versionchanged:: 3.3
-      *timeout* was added.
-
-
-.. function:: check_call(args, *, stdin=None, stdout=None, stderr=None, shell=False, timeout=None)
-
-   Run command with arguments.  Wait for command to complete. If the return
-   code was zero then return, otherwise raise :exc:`CalledProcessError`. The
-   :exc:`CalledProcessError` object will have the return code in the
-   :attr:`~CalledProcessError.returncode` attribute.
-
-   The arguments shown above are merely the most common ones, described below
-   in :ref:`frequently-used-arguments` (hence the use of keyword-only notation
-   in the abbreviated signature). The full function signature is largely the
-   same as that of the :class:`Popen` constructor - this function passes all
-   supplied arguments other than *timeout* directly through to that interface.
+   The *input* argument is passed to :meth:`Popen.communicate` and thus to the
+   subprocess's stdin.  If used it must be a byte sequence, or a string if
+   ``universal_newlines=True``.  When used, the internal :class:`Popen` object
+   is automatically created with ``stdin=PIPE``, and the *stdin* argument may
+   not be used as well.
 
-   The *timeout* argument is passed to :meth:`Popen.wait`. If the timeout
-   expires, the child process will be killed and then waited for again.  The
-   :exc:`TimeoutExpired` exception will be re-raised after the child process
-   has terminated.
+   If *check* is True, and the process exits with a non-zero exit code, a
+   :exc:`CalledProcessError` exception will be raised. Attributes of that
+   exception hold the arguments, the exit code, and stdout and stderr if they
+   were captured.
 
    Examples::
 
-      >>> subprocess.check_call(["ls", "-l"])
-      0
+      >>> subprocess.run(["ls", "-l"])  # doesn't capture output
+      CompletedProcess(args=['ls', '-l'], returncode=0)
 
-      >>> subprocess.check_call("exit 1", shell=True)
+      >>> subprocess.run("exit 1", shell=True, check=True)
       Traceback (most recent call last):
-         ...
+        ...
       subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1
 
-   .. note::
+      >>> subprocess.run(["ls", "-l", "/dev/null"], stdout=subprocess.PIPE)
+      CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0,
+      stdout=b'crw-rw-rw- 1 root root 1, 3 Jan 23 16:23 /dev/null\n')
 
-      Do not use ``stdout=PIPE`` or ``stderr=PIPE`` with this
-      function.  The child process will block if it generates enough
-      output to a pipe to fill up the OS pipe buffer as the pipes are
-      not being read from.
+   .. versionadded:: 3.5
 
-   .. versionchanged:: 3.3
-      *timeout* was added.
+.. class:: CompletedProcess
 
+   The return value from :func:`run`, representing a process that has finished.
 
-.. function:: check_output(args, *, input=None, stdin=None, stderr=None, shell=False, universal_newlines=False, timeout=None)
+   .. attribute:: args
 
-   Run command with arguments and return its output.
+      The arguments used to launch the process. This may be a list or a string.
 
-   If the return code was non-zero it raises a :exc:`CalledProcessError`. The
-   :exc:`CalledProcessError` object will have the return code in the
-   :attr:`~CalledProcessError.returncode` attribute and any output in the
-   :attr:`~CalledProcessError.output` attribute.
+   .. attribute:: returncode
 
-   The arguments shown above are merely the most common ones, described below
-   in :ref:`frequently-used-arguments` (hence the use of keyword-only notation
-   in the abbreviated signature). The full function signature is largely the
-   same as that of the :class:`Popen` constructor - this functions passes all
-   supplied arguments other than *input* and *timeout* directly through to
-   that interface.  In addition, *stdout* is not permitted as an argument, as
-   it is used internally to collect the output from the subprocess.
+      Exit status of the child process. Typically, an exit status of 0 indicates
+      that it ran successfully.
 
-   The *timeout* argument is passed to :meth:`Popen.wait`. If the timeout
-   expires, the child process will be killed and then waited for again.  The
-   :exc:`TimeoutExpired` exception will be re-raised after the child process
-   has terminated.
+      A negative value ``-N`` indicates that the child was terminated by signal
+      ``N`` (POSIX only).
 
-   The *input* argument is passed to :meth:`Popen.communicate` and thus to the
-   subprocess's stdin.  If used it must be a byte sequence, or a string if
-   ``universal_newlines=True``.  When used, the internal :class:`Popen` object
-   is automatically created with ``stdin=PIPE``, and the *stdin* argument may
-   not be used as well.
+   .. attribute:: stdout
 
-   Examples::
+      Captured stdout from the child process. A bytes sequence, or a string if
+      :func:`run` was called with ``universal_newlines=True``. None if stdout
+      was not captured.
 
-      >>> subprocess.check_output(["echo", "Hello World!"])
-      b'Hello World!\n'
+      If you ran the process with ``stderr=subprocess.STDOUT``, stdout and
+      stderr will be combined in this attribute, and :attr:`stderr` will be
+      None.
 
-      >>> subprocess.check_output(["echo", "Hello World!"], universal_newlines=True)
-      'Hello World!\n'
+   .. attribute:: stderr
 
-      >>> subprocess.check_output(["sed", "-e", "s/foo/bar/"],
-      ...                         input=b"when in the course of fooman events\n")
-      b'when in the course of barman events\n'
+      Captured stderr from the child process. A bytes sequence, or a string if
+      :func:`run` was called with ``universal_newlines=True``. None if stderr
+      was not captured.
 
-      >>> subprocess.check_output("exit 1", shell=True)
-      Traceback (most recent call last):
-         ...
-      subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1
+   .. method:: check_returncode()
 
-   By default, this function will return the data as encoded bytes. The actual
-   encoding of the output data may depend on the command being invoked, so the
-   decoding to text will often need to be handled at the application level.
+      If :attr:`returncode` is non-zero, raise a :exc:`CalledProcessError`.
 
-   This behaviour may be overridden by setting *universal_newlines* to
-   ``True`` as described below in :ref:`frequently-used-arguments`.
-
-   To also capture standard error in the result, use
-   ``stderr=subprocess.STDOUT``::
-
-      >>> subprocess.check_output(
-      ...     "ls non_existent_file; exit 0",
-      ...     stderr=subprocess.STDOUT,
-      ...     shell=True)
-      'ls: non_existent_file: No such file or directory\n'
-
-   .. note::
-
-      Do not use ``stdout=PIPE`` or ``stderr=PIPE`` with this
-      function.  The child process will block if it generates enough
-      output to a pipe to fill up the OS pipe buffer as the pipes are
-      not being read from.
-
-   .. versionadded:: 3.1
-
-   .. versionchanged:: 3.3
-      *timeout* was added.
-
-   .. versionchanged:: 3.4
-      *input* was added.
+   .. versionadded:: 3.5
 
 .. data:: DEVNULL
 
@@ -225,11 +164,22 @@ use cases, the underlying :class:`Popen` interface can be used directly.
 
     .. attribute:: output
 
-        Output of the child process if this exception is raised by
+        Output of the child process if it was captured by :func:`run` or
         :func:`check_output`.  Otherwise, ``None``.
 
+    .. attribute:: stdout
+
+        Alias for output, for symmetry with :attr:`stderr`.
+
+    .. attribute:: stderr
+
+        Stderr output of the child process if it was captured by :func:`run`.
+        Otherwise, ``None``.
+
     .. versionadded:: 3.3
 
+    .. versionchanged:: 3.5
+        *stdout* and *stderr* attributes added
 
 .. exception:: CalledProcessError
 
@@ -246,9 +196,20 @@ use cases, the underlying :class:`Popen` interface can be used directly.
 
     .. attribute:: output
 
-        Output of the child process if this exception is raised by
+        Output of the child process if it was captured by :func:`run` or
         :func:`check_output`.  Otherwise, ``None``.
 
+    .. attribute:: stdout
+
+        Alias for output, for symmetry with :attr:`stderr`.
+
+    .. attribute:: stderr
+
+        Stderr output of the child process if it was captured by :func:`run`.
+        Otherwise, ``None``.
+
+    .. versionchanged:: 3.5
+        *stdout* and *stderr* attributes added
 
 
 .. _frequently-used-arguments:
@@ -635,6 +596,7 @@ Instances of the :class:`Popen` class have the following methods:
    must be bytes or, if *universal_newlines* was ``True``, a string.
 
    :meth:`communicate` returns a tuple ``(stdout_data, stderr_data)``.
+   The data will be bytes or, if *universal_newlines* was ``True``, strings.
 
    Note that if you want to send data to the process's stdin, you need to create
    the Popen object with ``stdin=PIPE``.  Similarly, to get anything other than
@@ -851,6 +813,96 @@ The :mod:`subprocess` module exposes the following constants.
 
    This flag is ignored if :data:`CREATE_NEW_CONSOLE` is specified.
 
+.. _call-function-trio:
+
+Older high-level API
+--------------------
+
+Prior to Python 3.5, these three functions comprised the high level API to
+subprocess. You can now use :func:`run` in many cases, but lots of existing code
+calls these functions.
+
+.. function:: call(args, *, stdin=None, stdout=None, stderr=None, shell=False, timeout=None)
+
+   Run the command described by *args*.  Wait for command to complete, then
+   return the :attr:`returncode` attribute.
+
+   This is equivalent to::
+
+       run(...).returncode
+
+   (except that the *input* and *check* parameters are not supported)
+
+   .. note::
+
+      Do not use ``stdout=PIPE`` or ``stderr=PIPE`` with this
+      function.  The child process will block if it generates enough
+      output to a pipe to fill up the OS pipe buffer as the pipes are
+      not being read from.
+
+   .. versionchanged:: 3.3
+      *timeout* was added.
+
+.. function:: check_call(args, *, stdin=None, stdout=None, stderr=None, shell=False, timeout=None)
+
+   Run command with arguments.  Wait for command to complete. If the return
+   code was zero then return, otherwise raise :exc:`CalledProcessError`. The
+   :exc:`CalledProcessError` object will have the return code in the
+   :attr:`~CalledProcessError.returncode` attribute.
+
+   This is equivalent to::
+
+       run(..., check=True)
+
+   (except that the *input* parameter is not supported)
+
+   .. note::
+
+      Do not use ``stdout=PIPE`` or ``stderr=PIPE`` with this
+      function.  The child process will block if it generates enough
+      output to a pipe to fill up the OS pipe buffer as the pipes are
+      not being read from.
+
+   .. versionchanged:: 3.3
+      *timeout* was added.
+
+
+.. function:: check_output(args, *, input=None, stdin=None, stderr=None, shell=False, universal_newlines=False, timeout=None)
+
+   Run command with arguments and return its output.
+
+   If the return code was non-zero it raises a :exc:`CalledProcessError`. The
+   :exc:`CalledProcessError` object will have the return code in the
+   :attr:`~CalledProcessError.returncode` attribute and any output in the
+   :attr:`~CalledProcessError.output` attribute.
+
+   This is equivalent to::
+
+       run(..., check=True, stdout=PIPE).stdout
+
+   By default, this function will return the data as encoded bytes. The actual
+   encoding of the output data may depend on the command being invoked, so the
+   decoding to text will often need to be handled at the application level.
+
+   This behaviour may be overridden by setting *universal_newlines* to
+   ``True`` as described above in :ref:`frequently-used-arguments`.
+
+   To also capture standard error in the result, use
+   ``stderr=subprocess.STDOUT``::
+
+      >>> subprocess.check_output(
+      ...     "ls non_existent_file; exit 0",
+      ...     stderr=subprocess.STDOUT,
+      ...     shell=True)
+      'ls: non_existent_file: No such file or directory\n'
+
+   .. versionadded:: 3.1
+
+   .. versionchanged:: 3.3
+      *timeout* was added.
+
+   .. versionchanged:: 3.4
+      *input* was added.
 
 .. _subprocess-replacements:
 
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 3024086..3080b69 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -167,7 +167,7 @@ always available.
 
 .. data:: dont_write_bytecode
 
-   If this is true, Python won't try to write ``.pyc`` or ``.pyo`` files on the
+   If this is true, Python won't try to write ``.pyc`` files on the
    import of source modules.  This value is initially set to ``True`` or
    ``False`` depending on the :option:`-B` command line option and the
    :envvar:`PYTHONDONTWRITEBYTECODE` environment variable, but you can set it
@@ -718,6 +718,14 @@ always available.
    value of :func:`intern` around to benefit from it.
 
 
+.. function:: is_finalizing()
+
+   Return :const:`True` if the Python interpreter is
+   :term:`shutting down <interpreter shutdown>`, :const:`False` otherwise.
+
+   .. versionadded:: 3.5
+
+
 .. data:: last_type
           last_value
           last_traceback
@@ -1223,4 +1231,3 @@ always available.
 .. rubric:: Citations
 
 .. [C99] ISO/IEC 9899:1999.  "Programming languages -- C."  A public draft of this standard is available at http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf\ .
-
diff --git a/Doc/library/tarfile.rst b/Doc/library/tarfile.rst
index 05f29ad..adacb0a 100644
--- a/Doc/library/tarfile.rst
+++ b/Doc/library/tarfile.rst
@@ -62,6 +62,23 @@ Some facts and figures:
    +------------------+---------------------------------------------+
    | ``'r:xz'``       | Open for reading with lzma compression.     |
    +------------------+---------------------------------------------+
+   | ``'x'`` or       | Create a tarfile exclusively without        |
+   | ``'x:'``         | compression.                                |
+   |                  | Raise an :exc:`FileExistsError` exception   |
+   |                  | if it is already exists.                    |
+   +------------------+---------------------------------------------+
+   | ``'x:gz'``       | Create a tarfile with gzip compression.     |
+   |                  | Raise an :exc:`FileExistsError` exception   |
+   |                  | if it is already exists.                    |
+   +------------------+---------------------------------------------+
+   | ``'x:bz2'``      | Create a tarfile with bzip2 compression.    |
+   |                  | Raise an :exc:`FileExistsError` exception   |
+   |                  | if it is already exists.                    |
+   +------------------+---------------------------------------------+
+   | ``'x:xz'``       | Create a tarfile with lzma compression.     |
+   |                  | Raise an :exc:`FileExistsError` exception   |
+   |                  | if it is already exists.                    |
+   +------------------+---------------------------------------------+
    | ``'a' or 'a:'``  | Open for appending with no compression. The |
    |                  | file is created if it does not exist.       |
    +------------------+---------------------------------------------+
@@ -82,9 +99,9 @@ Some facts and figures:
    If *fileobj* is specified, it is used as an alternative to a :term:`file object`
    opened in binary mode for *name*. It is supposed to be at position 0.
 
-   For modes ``'w:gz'``, ``'r:gz'``, ``'w:bz2'``, ``'r:bz2'``, :func:`tarfile.open`
-   accepts the keyword argument *compresslevel* to specify the compression level of
-   the file.
+   For modes ``'w:gz'``, ``'r:gz'``, ``'w:bz2'``, ``'r:bz2'``, ``'x:gz'``,
+   ``'x:bz2'``, :func:`tarfile.open` accepts the keyword argument
+   *compresslevel* to specify the compression level of the file.
 
    For special purposes, there is a second format for *mode*:
    ``'filemode|[compression]'``.  :func:`tarfile.open` will return a :class:`TarFile`
@@ -127,6 +144,8 @@ Some facts and figures:
    |             | writing.                                   |
    +-------------+--------------------------------------------+
 
+   .. versionchanged:: 3.5
+      The ``'x'`` (exclusive creation) mode was added.
 
 .. class:: TarFile
 
@@ -252,8 +271,8 @@ be finalized; only the internally used file object will be closed. See the
    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.
+   data to an existing file, ``'w'`` to create a new file overwriting an existing
+   one or ``'x'`` to create a new file only if it's not exists.
 
    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
@@ -292,12 +311,14 @@ be finalized; only the internally used file object will be closed. See the
    to be handled. The default settings will work for most users.
    See section :ref:`tar-unicode` for in-depth information.
 
-   .. versionchanged:: 3.2
-      Use ``'surrogateescape'`` as the default for the *errors* argument.
-
    The *pax_headers* argument is an optional dictionary of strings which
    will be added as a pax global header if *format* is :const:`PAX_FORMAT`.
 
+   .. versionchanged:: 3.2
+      Use ``'surrogateescape'`` as the default for the *errors* argument.
+
+   .. versionchanged:: 3.5
+      The ``'x'`` (exclusive creation) mode was added.
 
 .. classmethod:: TarFile.open(...)
 
@@ -328,11 +349,15 @@ be finalized; only the internally used file object will be closed. See the
    returned by :meth:`getmembers`.
 
 
-.. method:: TarFile.list(verbose=True)
+.. method:: TarFile.list(verbose=True, *, members=None)
 
    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.
+   similar to that of :program:`ls -l` is produced. If optional *members* is
+   given, it must be a subset of the list returned by :meth:`getmembers`.
+
+   .. versionchanged:: 3.5
+      Added the *members* parameter.
 
 
 .. method:: TarFile.next()
@@ -342,7 +367,7 @@ be finalized; only the internally used file object will be closed. See the
    available.
 
 
-.. method:: TarFile.extractall(path=".", members=None)
+.. method:: TarFile.extractall(path=".", members=None, *, numeric_owner=False)
 
    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
@@ -352,6 +377,10 @@ be finalized; only the internally used file object will be closed. See the
    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.
 
+   If *numeric_owner* is :const:`True`, the uid and gid numbers from the tarfile
+   are used to set the owner/group for the extracted files. Otherwise, the named
+   values from the tarfile are used.
+
    .. warning::
 
       Never extract archives from untrusted sources without prior inspection.
@@ -359,8 +388,11 @@ be finalized; only the internally used file object will be closed. See the
       that have absolute filenames starting with ``"/"`` or filenames with two
       dots ``".."``.
 
+   .. versionchanged:: 3.5
+      Added the *numeric_only* parameter.
 
-.. method:: TarFile.extract(member, path="", set_attrs=True)
+
+.. method:: TarFile.extract(member, path="", set_attrs=True, *, numeric_owner=False)
 
    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*
@@ -368,6 +400,10 @@ be finalized; only the internally used file object will be closed. See the
    directory using *path*. File attributes (owner, mtime, mode) are set unless
    *set_attrs* is false.
 
+   If *numeric_owner* is :const:`True`, the uid and gid numbers from the tarfile
+   are used to set the owner/group for the extracted files. Otherwise, the named
+   values from the tarfile are used.
+
    .. note::
 
       The :meth:`extract` method does not take care of several extraction issues.
@@ -380,6 +416,9 @@ be finalized; only the internally used file object will be closed. See the
    .. versionchanged:: 3.2
       Added the *set_attrs* parameter.
 
+   .. versionchanged:: 3.5
+      Added the *numeric_only* parameter.
+
 .. method:: TarFile.extractfile(member)
 
    Extract a member from the archive as a file object. *member* may be a filename
@@ -802,4 +841,3 @@ In case of :const:`PAX_FORMAT` archives, *encoding* is generally not needed
 because all the metadata is stored using *UTF-8*. *encoding* is only used in
 the rare cases when binary pax headers are decoded or when strings with
 surrogate characters are stored.
-
diff --git a/Doc/library/tempfile.rst b/Doc/library/tempfile.rst
index 44d025d..2c68377 100644
--- a/Doc/library/tempfile.rst
+++ b/Doc/library/tempfile.rst
@@ -54,6 +54,13 @@ The module defines the following user-callable items:
    underlying true file object. This file-like object can be used in a
    :keyword:`with` statement, just like a normal file.
 
+   The :py:data:`os.O_TMPFILE` flag is used if it is available and works
+   (Linux-specific, require Linux kernel 3.11 or later).
+
+   .. versionchanged:: 3.5
+
+      The :py:data:`os.O_TMPFILE` flag is now used if available.
+
 
 .. function:: NamedTemporaryFile(mode='w+b', buffering=None, encoding=None, newline=None, suffix='', prefix='tmp', dir=None, delete=True)
 
diff --git a/Doc/library/test.rst b/Doc/library/test.rst
index 974909e..8f2df7c 100644
--- a/Doc/library/test.rst
+++ b/Doc/library/test.rst
@@ -568,6 +568,17 @@ The :mod:`test.support` module defines the following functions:
       def load_tests(*args):
           return load_package_tests(os.path.dirname(__file__), *args)
 
+.. function:: detect_api_mismatch(ref_api, other_api, *, ignore=()):
+
+   Returns the set of attributes, functions or methods of `ref_api` not
+   found on `other_api`, except for a defined list of items to be
+   ignored in this check specified in `ignore`.
+
+   By default this skips private attributes beginning with '_' but
+   includes all magic methods, i.e. those starting and ending in '__'.
+
+   .. versionadded:: 3.5
+
 
 The :mod:`test.support` module defines the following classes:
 
diff --git a/Doc/library/threading.rst b/Doc/library/threading.rst
index 0133a8f..5269994 100644
--- a/Doc/library/threading.rst
+++ b/Doc/library/threading.rst
@@ -630,7 +630,7 @@ item to the buffer only needs to wake up one consumer thread.
             cv.wait()
 
       Therefore, the same rules apply as with :meth:`wait`: The lock must be
-      held when called and is re-aquired on return.  The predicate is evaluated
+      held when called and is re-acquired on return.  The predicate is evaluated
       with the lock held.
 
       .. versionadded:: 3.2
diff --git a/Doc/library/time.rst b/Doc/library/time.rst
index 8d8b7d4..3d335c8 100644
--- a/Doc/library/time.rst
+++ b/Doc/library/time.rst
@@ -314,9 +314,9 @@ The module defines the following functions and data items:
    processes running for more than 49 days. On more recent versions of Windows
    and on other operating systems, :func:`monotonic` is system-wide.
 
-   Availability: Windows, Mac OS X, Linux, FreeBSD, OpenBSD, Solaris.
-
    .. versionadded:: 3.3
+   .. versionchanged:: 3.5
+      The function is now always available.
 
 
 .. function:: perf_counter()
@@ -350,6 +350,11 @@ The module defines the following functions and data items:
    requested by an arbitrary amount because of the scheduling of other activity
    in the system.
 
+   .. versionchanged:: 3.5
+      The function now sleeps at least *secs* even if the sleep is interrupted
+      by a signal, except if the signal handler raises an exception (see
+      :pep:`475` for the rationale).
+
 
 .. function:: strftime(format[, t])
 
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
index 70df409..d1051f6 100644
--- a/Doc/library/timeit.rst
+++ b/Doc/library/timeit.rst
@@ -59,18 +59,26 @@ Python Interface
 The module defines three convenience functions and a public class:
 
 
-.. function:: timeit(stmt='pass', setup='pass', timer=<default timer>, number=1000000)
+.. function:: timeit(stmt='pass', setup='pass', timer=<default timer>, number=1000000, globals=None)
 
    Create a :class:`Timer` instance with the given statement, *setup* code and
    *timer* function and run its :meth:`.timeit` method with *number* executions.
+   The optional *globals* argument specifies a namespace in which to execute the
+   code.
 
+   .. versionchanged:: 3.5
+      The optional *globals* parameter was added.
 
-.. function:: repeat(stmt='pass', setup='pass', timer=<default timer>, repeat=3, number=1000000)
+
+.. function:: repeat(stmt='pass', setup='pass', timer=<default timer>, repeat=3, number=1000000, globals=None)
 
    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.
+   count and *number* executions.  The optional *globals* argument specifies a
+   namespace in which to execute the code.
 
+   .. versionchanged:: 3.5
+      The optional *globals* parameter was added.
 
 .. function:: default_timer()
 
@@ -80,7 +88,7 @@ The module defines three convenience functions and a public class:
       :func:`time.perf_counter` is now the default timer.
 
 
-.. class:: Timer(stmt='pass', setup='pass', timer=<timer function>)
+.. class:: Timer(stmt='pass', setup='pass', timer=<timer function>, globals=None)
 
    Class for timing execution speed of small code snippets.
 
@@ -88,7 +96,9 @@ The module defines three convenience functions and a public class:
    for setup, and a timer function.  Both statements default to ``'pass'``;
    the timer function is platform-dependent (see the module doc string).
    *stmt* and *setup* may also contain multiple statements separated by ``;``
-   or newlines, as long as they don't contain multi-line string literals.
+   or newlines, as long as they don't contain multi-line string literals.  The
+   statement will by default be executed within timeit's namespace; this behavior
+   can be controlled by passing a namespace to *globals*.
 
    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`
@@ -101,6 +111,8 @@ The module defines three convenience functions and a public class:
    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.
 
+   .. versionchanged:: 3.5
+      The optional *globals* parameter was added.
 
    .. method:: Timer.timeit(number=1000000)
 
@@ -169,7 +181,7 @@ 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 ...]
+   python -m timeit [-n N] [-r N] [-u U] [-s S] [-t] [-c] [-h] [statement ...]
 
 Where the following options are understood:
 
@@ -198,6 +210,12 @@ Where the following options are understood:
 
    use :func:`time.time` (deprecated)
 
+.. cmdoption:: -u, --unit=U
+
+    specify a time unit for timer output; can select usec, msec, or sec
+
+   .. versionadded:: 3.5
+
 .. cmdoption:: -c, --clock
 
    use :func:`time.clock` (deprecated)
@@ -320,3 +338,17 @@ To give the :mod:`timeit` module access to functions you define, you can pass a
    if __name__ == '__main__':
        import timeit
        print(timeit.timeit("test()", setup="from __main__ import test"))
+
+Another option is to pass :func:`globals` to the  *globals* parameter, which will cause the code
+to be executed within your current global namespace.  This can be more convenient
+than individually specifying imports::
+
+   def f(x):
+       return x**2
+   def g(x):
+       return x**4
+   def h(x):
+       return x**8
+
+   import timeit
+   print(timeit.timeit('[func(42) for func in (f,g,h)]', globals=globals()))
diff --git a/Doc/library/tkinter.ttk.rst b/Doc/library/tkinter.ttk.rst
index 6f8bf1c..b0eefcb 100644
--- a/Doc/library/tkinter.ttk.rst
+++ b/Doc/library/tkinter.ttk.rst
@@ -1167,7 +1167,7 @@ Ttk Styling
 Each widget in :mod:`ttk` is assigned a style, which specifies the set of
 elements making up the widget and how they are arranged, along with dynamic
 and default settings for element options. By default the style name is the
-same as the widget's class name, but it may be overriden by the widget's style
+same as the widget's class name, but it may be overridden by the widget's style
 option. If you don't know the class name of a widget, use the method
 :meth:`Misc.winfo_class` (somewidget.winfo_class()).
 
diff --git a/Doc/library/token.rst b/Doc/library/token.rst
index 4cd7098..88fb38b 100644
--- a/Doc/library/token.rst
+++ b/Doc/library/token.rst
@@ -93,6 +93,7 @@ The token constants are:
           DOUBLESLASH
           DOUBLESLASHEQUAL
           AT
+          ATEQUAL
           RARROW
           ELLIPSIS
           OP
diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst
index 15fbedc..c6b5d0c 100644
--- a/Doc/library/traceback.rst
+++ b/Doc/library/traceback.rst
@@ -136,6 +136,162 @@ The module defines the following functions:
 
    .. versionadded:: 3.4
 
+.. function:: walk_stack(f)
+
+   Walk a stack following ``f.f_back`` from the given frame, yielding the frame
+   and line number for each frame. If *f* is ``None``, the current stack is
+   used. This helper is used with :meth:`StackSummary.extract`.
+
+   .. versionadded:: 3.5
+
+.. function:: walk_tb(tb)
+
+   Walk a traceback following ``tb_next`` yielding the frame and line number
+   for each frame. This helper is used with :meth:`StackSummary.extract`.
+
+   .. versionadded:: 3.5
+
+The module also defines the following classes:
+
+:class:`TracebackException` Objects
+-----------------------------------
+
+.. versionadded:: 3.5
+
+:class:`TracebackException` objects are created from actual exceptions to
+capture data for later printing in a lightweight fashion.
+
+.. class:: TracebackException(exc_type, exc_value, exc_traceback, *, limit=None, lookup_lines=True, capture_locals=False)
+
+   Capture an exception for later rendering. *limit*, *lookup_lines* and
+   *capture_locals* are as for the :class:`StackSummary` class.
+
+   Note that when locals are captured, they are also shown in the traceback.
+
+   .. attribute:: __cause__
+
+      A :class:`TracebackException` of the original ``__cause__``.
+
+   .. attribute:: __context__
+
+      A :class:`TracebackException` of the original ``__context__``.
+
+   .. attribute:: __suppress_context__
+
+      The ``__suppress_context__`` value from the original exception.
+
+   .. attribute:: stack
+
+      A :class:`StackSummary` representing the traceback.
+
+   .. attribute:: exc_type
+
+      The class of the original traceback.
+
+   .. attribute:: filename
+
+      For syntax errors - the file name where the error occurred.
+
+   .. attribute:: lineno
+
+      For syntax errors - the line number where the error occurred.
+
+   .. attribute:: text
+
+      For syntax errors - the text where the error occurred.
+
+   .. attribute:: offset
+
+      For syntax errors - the offset into the text where the error occurred.
+
+   .. attribute:: msg
+
+      For syntax errors - the compiler error message.
+
+   .. classmethod:: from_exception(exc, *, limit=None, lookup_lines=True, capture_locals=False)
+
+      Capture an exception for later rendering. *limit*, *lookup_lines* and
+      *capture_locals* are as for the :class:`StackSummary` class.
+
+      Note that when locals are captured, they are also shown in the traceback.
+
+   .. method:: format(*, chain=True)
+
+      Format the exception.
+
+      If *chain* is not ``True``, ``__cause__`` and ``__context__`` will not
+      be formatted.
+
+      The return value is a generator of strings, each ending in a newline and
+      some containing internal newlines. :func:`~traceback.print_exception`
+      is a wrapper around this method which just prints the lines to a file.
+
+      The message indicating which exception occurred is always the last
+      string in the output.
+
+   .. method::  format_exception_only()
+
+      Format the exception part of the traceback.
+
+      The return value is a generator of strings, each ending in a newline.
+
+      Normally, the generator emits a single string; however, for
+      :exc:`SyntaxError` exceptions, it emits several lines that (when
+      printed) display detailed information about where the syntax
+      error occurred.
+
+      The message indicating which exception occurred is always the last
+      string in the output.
+
+
+:class:`StackSummary` Objects
+-----------------------------
+
+.. versionadded:: 3.5
+
+:class:`StackSummary` objects represent a call stack ready for formatting.
+
+.. class:: StackSummary
+
+   .. classmethod:: extract(frame_gen, *, limit=None, lookup_lines=True, capture_locals=False)
+
+      Construct a :class:`StackSummary` object from a frame generator (such as
+      is returned by :func:`~traceback.walk_stack` or
+      :func:`~traceback.walk_tb`).
+
+      If *limit* is supplied, only this many frames are taken from *frame_gen*.
+      If *lookup_lines* is ``False``, the returned :class:`FrameSummary`
+      objects will not have read their lines in yet, making the cost of
+      creating the :class:`StackSummary` cheaper (which may be valuable if it
+      may not actually get formatted). If *capture_locals* is ``True`` the
+      local variables in each :class:`FrameSummary` are captured as object
+      representations.
+
+   .. classmethod:: from_list(a_list)
+
+      Construct a :class:`StackSummary` object from a supplied old-style list
+      of tuples. Each tuple should be a 4-tuple with filename, lineno, name,
+      line as the elements.
+
+
+:class:`FrameSummary` Objects
+-----------------------------
+
+.. versionadded:: 3.5
+
+:class:`FrameSummary` objects represent a single frame in a traceback.
+
+.. class:: FrameSummary(filename, lineno, name, lookup_line=True, locals=None, line=None)
+
+   Represent a single frame in the traceback or stack that is being formatted
+   or printed. It may optionally have a stringified version of the frames
+   locals included in it. If *lookup_line* is ``False``, the source code is not
+   looked up until the :class:`FrameSummary` has the :attr:`~FrameSummary.line`
+   attribute accessed (which also happens when casting it to a tuple).
+   :attr:`~FrameSummary.line` may be directly provided, and will prevent line
+   lookups happening at all. *locals* is an optional local variable
+   dictionary, and if supplied the variable representations are stored in the
+   summary for later display.
 
 .. _traceback-example:
 
diff --git a/Doc/library/tracemalloc.rst b/Doc/library/tracemalloc.rst
index 552e84b..13c81a7 100644
--- a/Doc/library/tracemalloc.rst
+++ b/Doc/library/tracemalloc.rst
@@ -350,7 +350,7 @@ Functions
    the *nframe* parameter of the :func:`start` function to store more frames.
 
    The :mod:`tracemalloc` module must be tracing memory allocations to take a
-   snapshot, see the the :func:`start` function.
+   snapshot, see the :func:`start` function.
 
    See also the :func:`get_object_traceback` function.
 
@@ -363,7 +363,7 @@ Filter
    Filter on traces of memory blocks.
 
    See the :func:`fnmatch.fnmatch` function for the syntax of
-   *filename_pattern*. The ``'.pyc'`` and ``'.pyo'`` file extensions are
+   *filename_pattern*. The ``'.pyc'`` file extension is
    replaced with ``'.py'``.
 
    Examples:
@@ -374,6 +374,10 @@ Filter
      :mod:`tracemalloc` module
    * ``Filter(False, "<unknown>")`` excludes empty tracebacks
 
+
+   .. versionchanged:: 3.5
+      The ``'.pyo'`` file extension is no longer replaced with ``'.py'``.
+
    .. attribute:: inclusive
 
       If *inclusive* is ``True`` (include), only trace memory blocks allocated
@@ -631,4 +635,3 @@ Traceback
               obj = Object()
             File "test.py", line 12
               tb = tracemalloc.get_object_traceback(f())
-
diff --git a/Doc/library/turtle.rst b/Doc/library/turtle.rst
index 5899f3d..30dd6ef 100644
--- a/Doc/library/turtle.rst
+++ b/Doc/library/turtle.rst
@@ -1809,7 +1809,7 @@ Input methods
 
    Pop up a dialog window for input of a number. title is the title of the
    dialog window, prompt is a text mostly describing what numerical information
-   to input. default: default value, minval: minimum value for imput,
+   to input. default: default value, minval: minimum value for input,
    maxval: maximum value for input
    The number input must be in the range minval .. maxval if these are
    given. If not, a hint is issued and the dialog remains open for
@@ -1879,7 +1879,7 @@ Settings and special methods
 
       >>> cv = screen.getcanvas()
       >>> cv
-      <turtle.ScrolledCanvas object at ...>
+      <turtle.ScrolledCanvas object ...>
 
 
 .. function:: getshapes()
@@ -2351,6 +2351,9 @@ The demo scripts are:
 |                | pairwise in opposite         | shapesize, tilt,      |
 |                | direction                    | get_shapepoly, update |
 +----------------+------------------------------+-----------------------+
+| sorting_animate| visual demonstration of      | simple alignment,     |
+|                | different sorting methods    | randomization         |
++----------------+------------------------------+-----------------------+
 | tree           | a (graphical) breadth        | :func:`clone`         |
 |                | first tree (using generators)|                       |
 +----------------+------------------------------+-----------------------+
@@ -2402,7 +2405,7 @@ Changes since Python 3.0
   Accordingly the latter has got an alias: :meth:`Screen.onkeyrelease`.
 
 - The method  :meth:`Screen.mainloop` has been added. So when working only
-  with Screen and Turtle objects one must not additonally import
+  with Screen and Turtle objects one must not additionally import
   :func:`mainloop` anymore.
 
 - Two input methods has been added :meth:`Screen.textinput` and
diff --git a/Doc/library/types.rst b/Doc/library/types.rst
index abdb939..34fffe6 100644
--- a/Doc/library/types.rst
+++ b/Doc/library/types.rst
@@ -115,6 +115,10 @@ Standard names are defined for the following types:
    The type of :term:`modules <module>`. Constructor takes the name of the
    module to be created and optionally its :term:`docstring`.
 
+   .. note::
+      Use :func:`importlib.util.module_from_spec` to create a new module if you
+      wish to set the various import-controlled attributes.
+
    .. attribute:: __doc__
 
       The :term:`docstring` of the module. Defaults to ``None``.
diff --git a/Doc/library/unicodedata.rst b/Doc/library/unicodedata.rst
index 3b3d3a0..24ddef8 100644
--- a/Doc/library/unicodedata.rst
+++ b/Doc/library/unicodedata.rst
@@ -15,8 +15,8 @@
 
 This module provides access to the Unicode Character Database (UCD) which
 defines character properties for all Unicode characters. The data contained in
-this database is compiled from the `UCD version 6.3.0
-<http://www.unicode.org/Public/6.3.0/ucd>`_.
+this database is compiled from the `UCD version 7.0.0
+<http://www.unicode.org/Public/7.0.0/ucd>`_.
 
 The module uses the same names and symbols as defined by Unicode
 Standard Annex #44, `"Unicode Character Database"
@@ -166,6 +166,6 @@ Examples:
 
 .. rubric:: Footnotes
 
-.. [#] http://www.unicode.org/Public/6.3.0/ucd/NameAliases.txt
+.. [#] http://www.unicode.org/Public/7.0.0/ucd/NameAliases.txt
 
-.. [#] http://www.unicode.org/Public/6.3.0/ucd/NamedSequences.txt
+.. [#] http://www.unicode.org/Public/7.0.0/ucd/NamedSequences.txt
diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst
index 91d5a27..f76c301 100644
--- a/Doc/library/unittest.mock.rst
+++ b/Doc/library/unittest.mock.rst
@@ -181,71 +181,77 @@ The Mock Class
 --------------
 
 
-`Mock` is a flexible mock object intended to replace the use of stubs and
+:class:`Mock` is a flexible mock object intended to replace the use of stubs and
 test doubles throughout your code. Mocks are callable and create attributes as
 new mocks when you access them [#]_. Accessing the same attribute will always
 return the same mock. Mocks record how you use them, allowing you to make
 assertions about what your code has done to them.
 
-:class:`MagicMock` is a subclass of `Mock` with all the magic methods
+:class:`MagicMock` is a subclass of :class:`Mock` with all the magic methods
 pre-created and ready to use. There are also non-callable variants, useful
 when you are mocking out objects that aren't callable:
 :class:`NonCallableMock` and :class:`NonCallableMagicMock`
 
 The :func:`patch` decorators makes it easy to temporarily replace classes
-in a particular module with a `Mock` object. By default `patch` will create
-a `MagicMock` for you. You can specify an alternative class of `Mock` using
-the `new_callable` argument to `patch`.
+in a particular module with a :class:`Mock` object. By default :func:`patch` will create
+a :class:`MagicMock` for you. You can specify an alternative class of :class:`Mock` using
+the *new_callable* argument to :func:`patch`.
 
 
-.. class:: Mock(spec=None, side_effect=None, return_value=DEFAULT, wraps=None, name=None, spec_set=None, **kwargs)
+.. class:: Mock(spec=None, side_effect=None, return_value=DEFAULT, wraps=None, name=None, spec_set=None, unsafe=False, **kwargs)
 
-    Create a new `Mock` object. `Mock` takes several optional arguments
+    Create a new :class:`Mock` object. :class:`Mock` takes several optional arguments
     that specify the behaviour of the Mock object:
 
-    * `spec`: This can be either a list of strings or an existing object (a
+    * *spec*: This can be either a list of strings or an existing object (a
       class or instance) that acts as the specification for the mock object. If
       you pass in an object then a list of strings is formed by calling dir on
       the object (excluding unsupported magic attributes and methods).
-      Accessing any attribute not in this list will raise an `AttributeError`.
+      Accessing any attribute not in this list will raise an :exc:`AttributeError`.
 
-      If `spec` is an object (rather than a list of strings) then
+      If *spec* is an object (rather than a list of strings) then
       :attr:`~instance.__class__` returns the class of the spec object. This
-      allows mocks to pass `isinstance` tests.
+      allows mocks to pass :func:`isinstance` tests.
 
-    * `spec_set`: A stricter variant of `spec`. If used, attempting to *set*
+    * *spec_set*: A stricter variant of *spec*. If used, attempting to *set*
       or get an attribute on the mock that isn't on the object passed as
-      `spec_set` will raise an `AttributeError`.
+      *spec_set* will raise an :exc:`AttributeError`.
 
-    * `side_effect`: A function to be called whenever the Mock is called. See
+    * *side_effect*: A function to be called whenever the Mock is called. See
       the :attr:`~Mock.side_effect` attribute. Useful for raising exceptions or
       dynamically changing return values. The function is called with the same
       arguments as the mock, and unless it returns :data:`DEFAULT`, the return
       value of this function is used as the return value.
 
-      Alternatively `side_effect` can be an exception class or instance. In
+      Alternatively *side_effect* can be an exception class or instance. In
       this case the exception will be raised when the mock is called.
 
-      If `side_effect` is an iterable then each call to the mock will return
+      If *side_effect* is an iterable then each call to the mock will return
       the next value from the iterable.
 
-      A `side_effect` can be cleared by setting it to `None`.
+      A *side_effect* can be cleared by setting it to ``None``.
 
-    * `return_value`: The value returned when the mock is called. By default
+    * *return_value*: The value returned when the mock is called. By default
       this is a new Mock (created on first access). See the
       :attr:`return_value` attribute.
 
-    * `wraps`: Item for the mock object to wrap. If `wraps` is not None then
+    * *unsafe*: By default if any attribute starts with *assert* or
+      *assret* will raise an :exc:`AttributeError`. Passing ``unsafe=True``
+      will allow access to these attributes.
+
+      .. versionadded:: 3.5
+
+    * *wraps*: Item for the mock object to wrap. If *wraps* is not None then
       calling the Mock will pass the call through to the wrapped object
       (returning the real result). Attribute access on the mock will return a
       Mock object that wraps the corresponding attribute of the wrapped
       object (so attempting to access an attribute that doesn't exist will
-      raise an `AttributeError`).
+      raise an :exc:`AttributeError`).
 
-      If the mock has an explicit `return_value` set then calls are not passed
-      to the wrapped object and the `return_value` is returned instead.
+      If the mock has an explicit *return_value* set then calls are not passed
+      to the wrapped object and the *return_value* is returned instead.
 
-    * `name`: If the mock has a name then it will be used in the repr of the
+    * *name*: If the mock has a name then it will be used in the repr of the
       mock. This can be useful for debugging. The name is propagated to child
       mocks.
 
@@ -315,6 +321,20 @@ the `new_callable` argument to `patch`.
             >>> calls = [call(4), call(2), call(3)]
             >>> mock.assert_has_calls(calls, any_order=True)
 
+    .. method:: assert_not_called(*args, **kwargs)
+
+        Assert the mock was never called.
+
+            >>> m = Mock()
+            >>> m.hello.assert_not_called()
+            >>> obj = m.hello()
+            >>> m.hello.assert_not_called()
+            Traceback (most recent call last):
+              ...
+            AssertionError: Expected 'hello' to not have been called. Called 1 times.
+
+        .. versionadded:: 3.5
+
 
     .. method:: reset_mock()
 
@@ -1032,25 +1052,31 @@ patch
     default because it can be dangerous. With it switched on you can write
     passing tests against APIs that don't actually exist!
 
-    Patch can be used as a `TestCase` class decorator. It works by
+    .. note::
+
+        .. versionchanged:: 3.5
+           If you are patching builtins in a module then you don't
+           need to pass ``create=True``, it will be added by default.
+
+    Patch can be used as a :class:`TestCase` class decorator. It works by
     decorating each test method in the class. This reduces the boilerplate
-    code when your test methods share a common patchings set. `patch` finds
-    tests by looking for method names that start with `patch.TEST_PREFIX`.
-    By default this is `test`, which matches the way `unittest` finds tests.
-    You can specify an alternative prefix by setting `patch.TEST_PREFIX`.
+    code when your test methods share a common patchings set. :func:`patch` finds
+    tests by looking for method names that start with ``patch.TEST_PREFIX``.
+    By default this is ``'test'``, which matches the way :mod:`unittest` finds tests.
+    You can specify an alternative prefix by setting ``patch.TEST_PREFIX``.
 
     Patch can be used as a context manager, with the with statement. Here the
     patching applies to the indented block after the with statement. If you
     use "as" then the patched object will be bound to the name after the
-    "as"; very useful if `patch` is creating a mock object for you.
+    "as"; very useful if :func:`patch` is creating a mock object for you.
 
-    `patch` takes arbitrary keyword arguments. These will be passed to
-    the `Mock` (or `new_callable`) on construction.
+    :func:`patch` takes arbitrary keyword arguments. These will be passed to
+    the :class:`Mock` (or *new_callable*) on construction.
 
-    `patch.dict(...)`, `patch.multiple(...)` and `patch.object(...)` are
+    ``patch.dict(...)``, ``patch.multiple(...)`` and ``patch.object(...)`` are
     available for alternate use-cases.
 
-`patch` as function decorator, creating the mock for you and passing it into
+:func:`patch` as function decorator, creating the mock for you and passing it into
 the decorated function:
 
     >>> @patch('__main__.SomeClass')
@@ -1392,15 +1418,31 @@ method of a :class:`TestCase`:
         ...         assert package.module.Class is self.MockClass
         ...
 
-    As an added bonus you no longer need to keep a reference to the `patcher`
+    As an added bonus you no longer need to keep a reference to the ``patcher``
     object.
 
 It is also possible to stop all patches which have been started by using
-`patch.stopall`.
+:func:`patch.stopall`.
 
 .. function:: patch.stopall
 
-    Stop all active patches. Only stops patches started with `start`.
+    Stop all active patches. Only stops patches started with ``start``.
+
+
+.. _patch-builtins:
+
+patch builtins
+~~~~~~~~~~~~~~
+You can patch any builtins within a module. The following example patches
+builtin :func:`ord`:
+
+    >>> @patch('__main__.ord')
+    ... def test(mock_ord):
+    ...     mock_ord.return_value = 101
+    ...     print(ord('c'))
+    ...
+    >>> test()
+    101
 
 
 TEST_PREFIX
@@ -1587,7 +1629,7 @@ The full list of supported magic methods is:
 * Context manager: ``__enter__`` and ``__exit__``
 * Unary numeric methods: ``__neg__``, ``__pos__`` and ``__invert__``
 * The numeric methods (including right hand and in-place variants):
-  ``__add__``, ``__sub__``, ``__mul__``, ``__div__``,``__truediv__``,
+  ``__add__``, ``__sub__``, ``__mul__``, ``__matmul__``, ``__div__``, ``__truediv__``,
   ``__floordiv__``, ``__mod__``, ``__divmod__``, ``__lshift__``,
   ``__rshift__``, ``__and__``, ``__xor__``, ``__or__``, and ``__pow__``
 * Numeric conversion methods: ``__complex__``, ``__int__``, ``__float__``
@@ -2013,7 +2055,7 @@ Mocking context managers with a :class:`MagicMock` is common enough and fiddly
 enough that a helper function is useful.
 
     >>> m = mock_open()
-    >>> with patch('__main__.open', m, create=True):
+    >>> with patch('__main__.open', m):
     ...     with open('foo', 'w') as h:
     ...         h.write('some stuff')
     ...
@@ -2028,7 +2070,7 @@ enough that a helper function is useful.
 
 And for reading files:
 
-    >>> with patch('__main__.open', mock_open(read_data='bibble'), create=True) as m:
+    >>> with patch('__main__.open', mock_open(read_data='bibble')) as m:
     ...     with open('foo') as h:
     ...         result = h.read()
     ...
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index bdb18bc..70f99a0 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -214,9 +214,16 @@ Command-line options
 
    Stop the test run on the first error or failure.
 
+.. cmdoption:: --locals
+
+   Show local variables in tracebacks.
+
 .. versionadded:: 3.2
    The command-line options ``-b``, ``-c`` and ``-f`` were added.
 
+.. versionadded:: 3.5
+   The command-line option ``--locals``.
+
 The command line can also be used for test discovery, for running all of the
 tests in a project or just a subset.
 
@@ -1543,6 +1550,20 @@ Loading and running tests
    :data:`unittest.defaultTestLoader`.  Using a subclass or instance, however,
    allows customization of some configurable properties.
 
+   :class:`TestLoader` objects have the following attributes:
+
+
+   .. attribute:: errors
+
+      A list of the non-fatal errors encountered while loading tests. Not reset
+      by the loader at any point. Fatal errors are signalled by the relevant
+      a method raising an exception to the caller. Non-fatal errors are also
+      indicated by a synthetic test that will raise the original error when
+      run.
+
+      .. versionadded:: 3.5
+
+
    :class:`TestLoader` objects have the following methods:
 
 
@@ -1552,7 +1573,7 @@ Loading and running tests
       :class:`testCaseClass`.
 
 
-   .. method:: loadTestsFromModule(module)
+   .. method:: loadTestsFromModule(module, pattern=None)
 
       Return a suite of all tests cases contained in the given module. This
       method searches *module* for classes derived from :class:`TestCase` and
@@ -1569,11 +1590,18 @@ Loading and running tests
 
       If a module provides a ``load_tests`` function it will be called to
       load the tests. This allows modules to customize test loading.
-      This is the `load_tests protocol`_.
+      This is the `load_tests protocol`_.  The *pattern* argument is passed as
+      the third argument to ``load_tests``.
 
       .. versionchanged:: 3.2
          Support for ``load_tests`` added.
 
+      .. versionchanged:: 3.5
+         The undocumented and unofficial *use_load_tests* default argument is
+         deprecated and ignored, although it is still accepted for backward
+         compatibility.  The method also now accepts a keyword-only argument
+         *pattern* which is passed to ``load_tests`` as the third argument.
+
 
    .. method:: loadTestsFromName(name, module=None)
 
@@ -1599,6 +1627,12 @@ Loading and running tests
 
       The method optionally resolves *name* relative to the given *module*.
 
+   .. versionchanged:: 3.5
+      If an :exc:`ImportError` or :exc:`AttributeError` occurs while traversing
+      *name* then a synthetic test that raises that error when run will be
+      returned. These errors are included in the errors accumulated by
+      self.errors.
+
 
    .. method:: loadTestsFromNames(names, module=None)
 
@@ -1625,18 +1659,22 @@ Loading and running tests
       the start directory is not the top level directory then the top level
       directory must be specified separately.
 
-      If importing a module fails, for example due to a syntax error, then this
-      will be recorded as a single error and discovery will continue.  If the
-      import failure is due to :exc:`SkipTest` being raised, it will be recorded
-      as a skip instead of an error.
+      If importing a module fails, for example due to a syntax error, then
+      this will be recorded as a single error and discovery will continue.  If
+      the import failure is due to :exc:`SkipTest` being raised, it will be
+      recorded as a skip instead of an error.
 
-      If a test package name (directory with :file:`__init__.py`) matches the
-      pattern then the package will be checked for a ``load_tests``
-      function. If this exists then it will be called with *loader*, *tests*,
-      *pattern*.
+      If a package (a directory containing a file named :file:`__init__.py`) is
+      found, the package will be checked for a ``load_tests`` function. If this
+      exists then it will be called
+      ``package.load_tests(loader, tests, pattern)``. Test discovery takes care
+      to ensure that a package is only checked for tests once during an
+      invocation, even if the load_tests function itself calls
+      ``loader.discover``.
 
-      If ``load_tests`` exists then discovery does *not* recurse into the package,
-      ``load_tests`` is responsible for loading all tests in the package.
+      If ``load_tests`` exists then discovery does *not* recurse into the
+      package, ``load_tests`` is responsible for loading all tests in the
+      package.
 
       The pattern is deliberately not stored as a loader attribute so that
       packages can continue discovery themselves. *top_level_dir* is stored so
@@ -1655,6 +1693,11 @@ Loading and running tests
            the same even if the underlying file system's ordering is not
            dependent on file name.
 
+      .. versionchanged:: 3.5
+         Found packages are now checked for ``load_tests`` regardless of
+         whether their path matches *pattern*, because it is impossible for
+         a package name to match the default pattern.
+
 
    The following attributes of a :class:`TestLoader` can be configured either by
    subclassing or assignment on an instance:
@@ -1737,12 +1780,10 @@ Loading and running tests
 
       Set to ``True`` when the execution of tests should stop by :meth:`stop`.
 
-
    .. attribute:: testsRun
 
       The total number of tests run so far.
 
-
    .. attribute:: buffer
 
       If set to true, ``sys.stdout`` and ``sys.stderr`` will be buffered in between
@@ -1752,7 +1793,6 @@ Loading and running tests
 
       .. versionadded:: 3.2
 
-
    .. attribute:: failfast
 
       If set to true :meth:`stop` will be called on the first failure or error,
@@ -1760,6 +1800,11 @@ Loading and running tests
 
       .. versionadded:: 3.2
 
+   .. attribute:: tb_locals
+
+      If set to true then local variables will be shown in tracebacks.
+
+      .. versionadded:: 3.5
 
    .. method:: wasSuccessful()
 
@@ -1770,7 +1815,6 @@ Loading and running tests
          Returns ``False`` if there were any :attr:`unexpectedSuccesses`
          from tests marked with the :func:`expectedFailure` decorator.
 
-
    .. method:: stop()
 
       This method can be called to signal that the set of tests being run should
@@ -1902,12 +1946,14 @@ Loading and running tests
 
 
 .. class:: TextTestRunner(stream=None, descriptions=True, verbosity=1, failfast=False, \
-                          buffer=False, resultclass=None, warnings=None)
+                          buffer=False, resultclass=None, warnings=None, *, tb_locals=False)
 
    A basic test runner implementation that outputs results to a stream. If *stream*
    is ``None``, the default, :data:`sys.stderr` is used as the output stream. This class
    has a few configurable parameters, but is essentially very simple.  Graphical
-   applications which run test suites should provide alternate implementations.
+   applications which run test suites should provide alternate implementations. Such
+   implementations should accept ``**kwargs`` as the interface to construct runners
+   changes when features are added to unittest.
 
    By default this runner shows :exc:`DeprecationWarning`,
    :exc:`PendingDeprecationWarning`, :exc:`ResourceWarning` and
@@ -1926,6 +1972,9 @@ Loading and running tests
       The default stream is set to :data:`sys.stderr` at instantiation time rather
       than import time.
 
+   .. versionchanged:: 3.5
+      Added the tb_locals parameter.
+
    .. method:: _makeResult()
 
       This method returns the instance of ``TestResult`` used by :meth:`run`.
@@ -2023,7 +2072,10 @@ test runs or test discovery by implementing a function called ``load_tests``.
 If a test module defines ``load_tests`` it will be called by
 :meth:`TestLoader.loadTestsFromModule` with the following arguments::
 
-    load_tests(loader, standard_tests, None)
+    load_tests(loader, standard_tests, pattern)
+
+where *pattern* is passed straight through from ``loadTestsFromModule``.  It
+defaults to ``None``.
 
 It should return a :class:`TestSuite`.
 
@@ -2045,21 +2097,12 @@ A typical ``load_tests`` function that loads tests from a specific set of
             suite.addTests(tests)
         return suite
 
-If discovery is started, either from the command line or by calling
-:meth:`TestLoader.discover`, with a pattern that matches a package
-name then the package :file:`__init__.py` will be checked for ``load_tests``.
-
-.. note::
-
-   The default pattern is ``'test*.py'``. This matches all Python files
-   that start with ``'test'`` but *won't* match any test directories.
-
-   A pattern like ``'test*'`` will match test packages as well as
-   modules.
-
-If the package :file:`__init__.py` defines ``load_tests`` then it will be
-called and discovery not continued into the package. ``load_tests``
-is called with the following arguments::
+If discovery is started in a directory containing a package, either from the
+command line or by calling :meth:`TestLoader.discover`, then the package
+:file:`__init__.py` will be checked for ``load_tests``.  If that function does
+not exist, discovery will recurse into the package as though it were just
+another directory.  Otherwise, discovery of the package's tests will be left up
+to ``load_tests`` which is called with the following arguments::
 
     load_tests(loader, standard_tests, pattern)
 
@@ -2078,6 +2121,11 @@ continue (and potentially modify) test discovery. A 'do nothing'
         standard_tests.addTests(package_tests)
         return standard_tests
 
+.. versionchanged:: 3.5
+   Discovery no longer checks package names for matching *pattern* due to the
+   impossibility of package names matching the default pattern.
+
+
 
 Class and Module Fixtures
 -------------------------
diff --git a/Doc/library/urllib.parse.rst b/Doc/library/urllib.parse.rst
index 154a521..3ecdda1 100644
--- a/Doc/library/urllib.parse.rst
+++ b/Doc/library/urllib.parse.rst
@@ -268,6 +268,11 @@ or on combining URL components into a URL string.
    :func:`urlunsplit`, removing possible *scheme* and *netloc* parts.
 
 
+   .. versionchanged:: 3.5
+
+      Behaviour updated to match the semantics defined in :rfc:`3986`.
+
+
 .. function:: urldefrag(url)
 
    If *url* contains a fragment identifier, return a modified version of *url*
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 03ce752..349ba70 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -68,7 +68,7 @@ The :mod:`urllib.request` module defines the following functions:
    :class:`http.client.HTTPResponse` object which has the following
    :ref:`httpresponse-objects` methods.
 
-   For ftp, file, and data urls and requests explicity handled by legacy
+   For ftp, file, and data urls and requests explicitly handled by legacy
    :class:`URLopener` and :class:`FancyURLopener` classes, this function
    returns a :class:`urllib.response.addinfourl` object which can work as
    :term:`context manager` and has methods such as
@@ -115,6 +115,7 @@ The :mod:`urllib.request` module defines the following functions:
    .. versionchanged:: 3.4.3
       *context* was added.
 
+
 .. function:: install_opener(opener)
 
    Install an :class:`OpenerDirector` instance as the default global opener.
@@ -287,13 +288,37 @@ The following classes are provided:
    fits.
 
 
+.. class:: HTTPPasswordMgrWithPriorAuth()
+
+   A variant of :class:`HTTPPasswordMgrWithDefaultRealm` that also has a
+   database of ``uri -> is_authenticated`` mappings.  Can be used by a
+   BasicAuth handler to determine when to send authentication credentials
+   immediately instead of waiting for a ``401`` response first.
+
+   .. versionadded:: 3.5
+
+
 .. class:: AbstractBasicAuthHandler(password_mgr=None)
 
    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.
+   supported.  If *passwd_mgr* also provides ``is_authenticated`` and
+   ``update_authenticated`` methods (see
+   :ref:`http-password-mgr-with-prior-auth`), then the handler will use the
+   ``is_authenticated`` result for a given URI to determine whether or not to
+   send authentication credentials with the request.  If ``is_authenticated``
+   returns ``True`` for the URI, credentials are sent.  If ``is_authenticated``
+   is ``False``, credentials are not sent, and then if a ``401`` response is
+   received the request is re-sent with the authentication credentials.  If
+   authentication succeeds, ``update_authenticated`` is called to set
+   ``is_authenticated`` ``True`` for the URI, so that subsequent requests to
+   the URI or any of its super-URIs will automatically include the
+   authentication credentials.
+
+   .. versionadded:: 3.5
+      Added ``is_authenticated`` support.
 
 
 .. class:: HTTPBasicAuthHandler(password_mgr=None)
@@ -845,6 +870,42 @@ These methods are available on :class:`HTTPPasswordMgr` and
    searched if the given *realm* has no matching user/password.
 
 
+.. _http-password-mgr-with-prior-auth:
+
+HTTPPasswordMgrWithPriorAuth Objects
+------------------------------------
+
+This password manager extends :class:`HTTPPasswordMgrWithDefaultRealm` to support
+tracking URIs for which authentication credentials should always be sent.
+
+
+.. method:: HTTPPasswordMgrWithPriorAuth.add_password(realm, uri, user, \
+            passwd, is_authenticated=False)
+
+   *realm*, *uri*, *user*, *passwd* are as for
+   :meth:`HTTPPasswordMgr.add_password`.  *is_authenticated* sets the initial
+   value of the ``is_authenticated`` flag for the given URI or list of URIs.
+   If *is_authenticated* is specified as ``True``, *realm* is ignored.
+
+
+.. method:: HTTPPasswordMgr.find_user_password(realm, authuri)
+
+   Same as for :class:`HTTPPasswordMgrWithDefaultRealm` objects
+
+
+.. method:: HTTPPasswordMgrWithPriorAuth.update_authenticated(self, uri, \
+            is_authenticated=False)
+
+   Update the ``is_authenticated`` flag for the given *uri* or list
+   of URIs.
+
+
+.. method:: HTTPPasswordMgrWithPriorAuth.is_authenticated(self, authuri)
+
+   Returns the current state of the ``is_authenticated`` flag for
+   the given URI.
+
+
 .. _abstract-basic-auth-handler:
 
 AbstractBasicAuthHandler Objects
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
index 9ca60a9..2e16077 100644
--- a/Doc/library/weakref.rst
+++ b/Doc/library/weakref.rst
@@ -258,7 +258,7 @@ These method have the same issues as the and :meth:`keyrefs` method of
    are called in reverse order of creation.
 
    A finalizer will never invoke its callback during the later part of
-   the interpreter shutdown when module globals are liable to have
+   the :term:`interpreter shutdown` when module globals are liable to have
    been replaced by :const:`None`.
 
    .. method:: __call__()
@@ -527,8 +527,8 @@ follows::
 
 Starting with Python 3.4, :meth:`__del__` methods no longer prevent
 reference cycles from being garbage collected, and module globals are
-no longer forced to :const:`None` during interpreter shutdown. So this
-code should work without any issues on CPython.
+no longer forced to :const:`None` during :term:`interpreter shutdown`.
+So this code should work without any issues on CPython.
 
 However, handling of :meth:`__del__` methods is notoriously implementation
 specific, since it depends on internal details of the interpreter's garbage
@@ -566,8 +566,8 @@ third party, such as running code when a module is unloaded::
 
 .. note::
 
-   If you create a finalizer object in a daemonic thread just as the
-   the program exits then there is the possibility that the finalizer
+   If you create a finalizer object in a daemonic thread just as the program
+   exits then there is the possibility that the finalizer
    does not get called at exit.  However, in a daemonic thread
    :func:`atexit.register`, ``try: ... finally: ...`` and ``with: ...``
    do not guarantee that cleanup occurs either.
diff --git a/Doc/library/webbrowser.rst b/Doc/library/webbrowser.rst
index ef63769..aa5e4ad 100644
--- a/Doc/library/webbrowser.rst
+++ b/Doc/library/webbrowser.rst
@@ -20,7 +20,7 @@ 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 as the
-:data:`os.pathsep`-separated list of browsers to try ahead of the the platform
+:data:`os.pathsep`-separated list of browsers to try ahead of the platform
 defaults.  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
diff --git a/Doc/library/wsgiref.rst b/Doc/library/wsgiref.rst
index a9e19da..de74c30 100644
--- a/Doc/library/wsgiref.rst
+++ b/Doc/library/wsgiref.rst
@@ -184,10 +184,11 @@ This module provides a single class, :class:`Headers`, for convenient
 manipulation of WSGI response headers using a mapping-like interface.
 
 
-.. class:: Headers(headers)
+.. class:: Headers([headers])
 
    Create a mapping-like object wrapping *headers*, which must be a list of header
-   name/value tuples as described in :pep:`3333`.
+   name/value tuples as described in :pep:`3333`. The default value of *headers* is
+   an empty list.
 
    :class:`Headers` objects support typical mapping operations including
    :meth:`__getitem__`, :meth:`get`, :meth:`__setitem__`, :meth:`setdefault`,
@@ -251,6 +252,10 @@ manipulation of WSGI response headers using a mapping-like interface.
          Content-Disposition: attachment; filename="bud.gif"
 
 
+   .. versionchanged:: 3.5
+      *headers* parameter is optional.
+
+
 :mod:`wsgiref.simple_server` -- a simple WSGI HTTP server
 ---------------------------------------------------------
 
diff --git a/Doc/library/xml.dom.rst b/Doc/library/xml.dom.rst
index 19512ed..4914738 100644
--- a/Doc/library/xml.dom.rst
+++ b/Doc/library/xml.dom.rst
@@ -412,7 +412,7 @@ 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
+   index *i* is not allowed to be less than zero or greater than or equal to the
    length of the sequence.
 
 
diff --git a/Doc/library/xml.sax.reader.rst b/Doc/library/xml.sax.reader.rst
index 3ab6063..31ca260 100644
--- a/Doc/library/xml.sax.reader.rst
+++ b/Doc/library/xml.sax.reader.rst
@@ -100,8 +100,10 @@ The :class:`XMLReader` interface supports the following methods:
    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.
+   can be discarded or reset.
+
+   .. versionchanged:: 3.5
+      Added support of character streams.
 
 
 .. method:: XMLReader.getContentHandler()
@@ -288,8 +290,7 @@ InputSource Objects
 
 .. 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.
+   Set the byte stream (a :term:`binary file`) 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.
@@ -308,8 +309,7 @@ InputSource Objects
 
 .. 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 strings.)
+   Set the character stream (a :term:`text file`) for this input source.
 
    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.
diff --git a/Doc/library/xml.sax.rst b/Doc/library/xml.sax.rst
index e95d6b0..55f9799 100644
--- a/Doc/library/xml.sax.rst
+++ b/Doc/library/xml.sax.rst
@@ -47,7 +47,11 @@ The convenience functions are:
 .. function:: parseString(string, handler, error_handler=handler.ErrorHandler())
 
    Similar to :func:`parse`, but parses from a buffer *string* received as a
-   parameter.
+   parameter.  *string* must be a :class:`str` instance or a
+   :term:`bytes-like object`.
+
+   .. versionchanged:: 3.5
+      Added support of :class:`str` instances.
 
 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
diff --git a/Doc/library/xmlrpc.client.rst b/Doc/library/xmlrpc.client.rst
index cc5e83a..e199931 100644
--- a/Doc/library/xmlrpc.client.rst
+++ b/Doc/library/xmlrpc.client.rst
@@ -27,7 +27,7 @@ between conformable Python objects and XML on the wire.
    constructed data.  If you need to parse untrusted or unauthenticated data see
    :ref:`xml-vulnerabilities`.
 
-.. versionchanged:: 3.4.3
+.. versionchanged:: 3.5
 
    For https URIs, :mod:`xmlrpc.client` now performs all the necessary
    certificate and hostname checks by default
@@ -129,7 +129,7 @@ between conformable Python objects and XML on the wire.
    :class:`Server` is retained as an alias for :class:`ServerProxy` for backwards
    compatibility.  New code should use :class:`ServerProxy`.
 
-   .. versionchanged:: 3.4.3
+   .. versionchanged:: 3.5
       Added the *context* argument.
 
 
@@ -200,6 +200,11 @@ grouped under the reserved :attr:`system` attribute:
    no such string is available, an empty string is returned. The documentation
    string may contain HTML markup.
 
+.. versionchanged:: 3.5
+
+   Instances of :class:`ServerProxy` support the :term:`context manager` protocol
+   for closing the underlying transport.
+
 
 A working example follows. The server code::
 
@@ -217,9 +222,9 @@ The client code for the preceding server::
 
    import xmlrpc.client
 
-   proxy = xmlrpc.client.ServerProxy("http://localhost:8000/")
-   print("3 is even: %s" % str(proxy.is_even(3)))
-   print("100 is even: %s" % str(proxy.is_even(100)))
+   with xmlrpc.client.ServerProxy("http://localhost:8000/") as proxy:
+       print("3 is even: %s" % str(proxy.is_even(3)))
+       print("100 is even: %s" % str(proxy.is_even(100)))
 
 .. _datetime-objects:
 
@@ -527,14 +532,14 @@ Example of Client Usage
    from xmlrpc.client import ServerProxy, Error
 
    # server = ServerProxy("http://localhost:8000") # local server
-   server = ServerProxy("http://betty.userland.com")
+   with ServerProxy("http://betty.userland.com") as proxy:
 
-   print(server)
+       print(proxy)
 
-   try:
-       print(server.examples.getStateName(41))
-   except Error as v:
-       print("ERROR", v)
+       try:
+           print(proxy.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 shows how:
diff --git a/Doc/library/zipapp.rst b/Doc/library/zipapp.rst
new file mode 100644
index 0000000..b4484c8
--- /dev/null
+++ b/Doc/library/zipapp.rst
@@ -0,0 +1,259 @@
+:mod:`zipapp` --- Manage executable python zip archives
+=======================================================
+
+.. module:: zipapp
+   :synopsis: Manage executable python zip archives
+
+
+.. index::
+   single: Executable Zip Files
+
+.. versionadded:: 3.5
+
+**Source code:** :source:`Lib/zipapp.py`
+
+--------------
+
+This module provides tools to manage the creation of zip files containing
+Python code, which can be  :ref:`executed directly by the Python interpreter
+<using-on-interface-options>`.  The module provides both a
+:ref:`zipapp-command-line-interface` and a :ref:`zipapp-python-api`.
+
+
+Basic Example
+-------------
+
+The following example shows how the :ref:`command-line-interface`
+can be used to create an executable archive from a directory containing
+Python code.  When run, the archive will execute the ``main`` function from
+the module ``myapp`` in the archive.
+
+.. code-block:: sh
+
+   $ python -m zipapp myapp -m "myapp:main"
+   $ python myapp.pyz
+   <output from myapp>
+
+
+.. _zipapp-command-line-interface:
+
+Command-Line Interface
+----------------------
+
+When called as a program from the command line, the following form is used:
+
+.. code-block:: sh
+
+   $ python -m zipapp source [options]
+
+If *source* is a directory, this will create an archive from the contents of
+*source*.  If *source* is a file, it should be an archive, and it will be
+copied to the target archive (or the contents of its shebang line will be
+displayed if the --info option is specified).
+
+The following options are understood:
+
+.. program:: zipapp
+
+.. cmdoption:: -o <output>, --output=<output>
+
+   Write the output to a file named *output*.  If this option is not specified,
+   the output filename will be the same as the input *source*, with the
+   extension ``.pyz`` added.  If an explicit filename is given, it is used as
+   is (so a ``.pyz`` extension should be included if required).
+
+   An output filename must be specified if the *source* is an archive (and in
+   that case, *output* must not be the same as *source*).
+
+.. cmdoption:: -p <interpreter>, --python=<interpreter>
+
+   Add a ``#!`` line to the archive specifying *interpreter* as the command
+   to run.  Also, on POSIX, make the archive executable.  The default is to
+   write no ``#!`` line, and not make the file executable.
+
+.. cmdoption:: -m <mainfn>, --main=<mainfn>
+
+   Write a ``__main__.py`` file to the archive that executes *mainfn*.  The
+   *mainfn* argument should have the form "pkg.mod:fn", where "pkg.mod" is a
+   package/module in the archive, and "fn" is a callable in the given module.
+   The ``__main__.py`` file will execute that callable.
+
+   :option:`--main` cannot be specified when copying an archive.
+
+.. cmdoption:: --info
+
+   Display the interpreter embedded in the archive, for diagnostic purposes.  In
+   this case, any other options are ignored and SOURCE must be an archive, not a
+   directory.
+
+.. cmdoption:: -h, --help
+
+   Print a short usage message and exit.
+
+
+.. _zipapp-python-api:
+
+Python API
+----------
+
+The module defines two convenience functions:
+
+
+.. function:: create_archive(source, target=None, interpreter=None, main=None)
+
+   Create an application archive from *source*.  The source can be any
+   of the following:
+
+   * The name of a directory, or a :class:`pathlib.Path` object referring
+     to a directory, in which case a new application archive will be
+     created from the content of that directory.
+   * The name of an existing application archive file, or a :class:`pathlib.Path`
+     object referring to such a file, in which case the file is copied to
+     the target (modifying it to reflect the value given for the *interpreter*
+     argument).  The file name should include the ``.pyz`` extension, if required.
+   * A file object open for reading in bytes mode.  The content of the
+     file should be an application archive, and the file object is
+     assumed to be positioned at the start of the archive.
+
+   The *target* argument determines where the resulting archive will be
+   written:
+
+   * If it is the name of a file, or a :class:`pathlb.Path` object,
+     the archive will be written to that file.
+   * If it is an open file object, the archive will be written to that
+     file object, which must be open for writing in bytes mode.
+   * If the target is omitted (or None), the source must be a directory
+     and the target will be a file with the same name as the source, with
+     a ``.pyz`` extension added.
+
+   The *interpreter* argument specifies the name of the Python
+   interpreter with which the archive will be executed.  It is written as
+   a "shebang" line at the start of the archive.  On POSIX, this will be
+   interpreted by the OS, and on Windows it will be handled by the Python
+   launcher.  Omitting the *interpreter* results in no shebang line being
+   written.  If an interpreter is specified, and the target is a
+   filename, the executable bit of the target file will be set.
+
+   The *main* argument specifies the name of a callable which will be
+   used as the main program for the archive.  It can only be specified if
+   the source is a directory, and the source does not already contain a
+   ``__main__.py`` file.  The *main* argument should take the form
+   "pkg.module:callable" and the archive will be run by importing
+   "pkg.module" and executing the given callable with no arguments.  It
+   is an error to omit *main* if the source is a directory and does not
+   contain a ``__main__.py`` file, as otherwise the resulting archive
+   would not be executable.
+
+   If a file object is specified for *source* or *target*, it is the
+   caller's responsibility to close it after calling create_archive.
+
+   When copying an existing archive, file objects supplied only need
+   ``read`` and ``readline``, or ``write`` methods.  When creating an
+   archive from a directory, if the target is a file object it will be
+   passed to the ``zipfile.ZipFile`` class, and must supply the methods
+   needed by that class.
+
+.. function:: get_interpreter(archive)
+
+   Return the interpreter specified in the ``#!`` line at the start of the
+   archive.  If there is no ``#!`` line, return :const:`None`.
+   The *archive* argument can be a filename or a file-like object open
+   for reading in bytes mode.  It is assumed to be at the start of the archive.
+
+
+.. _zipapp-examples:
+
+Examples
+--------
+
+Pack up a directory into an archive, and run it.
+
+.. code-block:: sh
+
+   $ python -m zipapp myapp
+   $ python myapp.pyz
+   <output from myapp>
+
+The same can be done using the :func:`create_archive` functon::
+
+   >>> import zipapp
+   >>> zipapp.create_archive('myapp.pyz', 'myapp')
+
+To make the application directly executable on POSIX, specify an interpreter
+to use.
+
+.. code-block:: sh
+
+   $ python -m zipapp myapp -p "/usr/bin/env python"
+   $ ./myapp.pyz
+   <output from myapp>
+
+To replace the shebang line on an existing archive, create a modified archive
+using the :func:`create_archive` function::
+
+   >>> import zipapp
+   >>> zipapp.create_archive('old_archive.pyz', 'new_archive.pyz', '/usr/bin/python3')
+
+To update the file in place, do the replacement in memory using a :class:`BytesIO`
+object, and then overwrite the source afterwards.  Note that there is a risk
+when overwriting a file in place that an error will result in the loss of
+the original file.  This code does not protect against such errors, but
+production code should do so.  Also, this method will only work if the archive
+fits in memory::
+
+   >>> import zipapp
+   >>> import io
+   >>> temp = io.BytesIO()
+   >>> zipapp.create_archive('myapp.pyz', temp, '/usr/bin/python2')
+   >>> with open('myapp.pyz', 'wb') as f:
+   >>>     f.write(temp.getvalue())
+
+Note that if you specify an interpreter and then distribute your application
+archive, you need to ensure that the interpreter used is portable.  The Python
+launcher for Windows supports most common forms of POSIX ``#!`` line, but there
+are other issues to consider:
+
+* If you use "/usr/bin/env python" (or other forms of the "python" command,
+  such as "/usr/bin/python"), you need to consider that your users may have
+  either Python 2 or Python 3 as their default, and write your code to work
+  under both versions.
+* If you use an explicit version, for example "/usr/bin/env python3" your
+  application will not work for users who do not have that version.  (This
+  may be what you want if you have not made your code Python 2 compatible).
+* There is no way to say "python X.Y or later", so be careful of using an
+  exact version like "/usr/bin/env python3.4" as you will need to change your
+  shebang line for users of Python 3.5, for example.
+
+The Python Zip Application Archive Format
+-----------------------------------------
+
+Python has been able to execute zip files which contain a ``__main__.py`` file
+since version 2.6.  In order to be executed by Python, an application archive
+simply has to be a standard zip file containing a ``__main__.py`` file which
+will be run as the entry point for the application.  As usual for any Python
+script, the parent of the script (in this case the zip file) will be placed on
+:data:`sys.path` and thus further modules can be imported from the zip file.
+
+The zip file format allows arbitrary data to be prepended to a zip file.  The
+zip application format uses this ability to prepend a standard POSIX "shebang"
+line to the file (``#!/path/to/interpreter``).
+
+Formally, the Python zip application format is therefore:
+
+1. An optional shebang line, containing the characters ``b'#!'`` followed by an
+   interpreter name, and then a newline (``b'\n'``) character.  The interpreter
+   name can be anything acceptable to the OS "shebang" processing, or the Python
+   launcher on Windows.  The interpreter should be encoded in UTF-8 on Windows,
+   and in :func:`sys.getfilesystemencoding()` on POSIX.
+2. Standard zipfile data, as generated by the :mod:`zipfile` module.  The
+   zipfile content *must* include a file called ``__main__.py`` (which must be
+   in the "root" of the zipfile - i.e., it cannot be in a subdirectory).  The
+   zipfile data can be compressed or uncompressed.
+
+If an application archive has a shebang line, it may have the executable bit set
+on POSIX systems, to allow it to be executed directly.
+
+There is no requirement that the tools in this module are used to create
+application archives - the module is a convenience, but archives in the above
+format created by any means are acceptable to Python.
+
diff --git a/Doc/library/zipfile.rst b/Doc/library/zipfile.rst
index 10a094f..d40315e 100644
--- a/Doc/library/zipfile.rst
+++ b/Doc/library/zipfile.rst
@@ -134,12 +134,16 @@ ZipFile Objects
 
    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, ``'w'`` to truncate and write a new file, ``'x'`` to exclusive create
+   and write a new file, or ``'a'`` to append to an existing file.
+   If *mode* is ``'x'`` and *file* refers to an existing file,
+   a :exc:`FileExistsError` will be raised.
+   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`).  If
    *mode* is ``a`` and the file does not exist at all, it is created.
+   If *mode* is ``r`` or ``a``, the file should be seekable.
    *compression* is the ZIP compression method to use when writing the archive,
    and should be :const:`ZIP_STORED`, :const:`ZIP_DEFLATED`,
    :const:`ZIP_BZIP2` or :const:`ZIP_LZMA`; unrecognized
@@ -151,7 +155,7 @@ ZipFile Objects
    extensions when the zipfile is larger than 2 GiB. If it is  false :mod:`zipfile`
    will raise an exception when the ZIP file would require ZIP64 extensions.
 
-   If the file is created with mode ``'a'`` or ``'w'`` and then
+   If the file is created with mode ``'w'``, ``'x'`` or ``'a'`` and then
    :meth:`closed <close>` without adding any files to the archive, the appropriate
    ZIP structures for an empty archive will be written to the file.
 
@@ -171,6 +175,10 @@ ZipFile Objects
    .. versionchanged:: 3.4
       ZIP64 extensions are enabled by default.
 
+   .. versionchanged:: 3.5
+      Added support for writing to unseekable streams.
+      Added support for the ``'x'`` mode.
+
 
 .. method:: ZipFile.close()
 
@@ -226,14 +234,8 @@ ZipFile Objects
 
    .. 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.
+      Objects returned by :meth:`.open` can operate independently of the
+      ZipFile.
 
    .. note::
 
@@ -318,7 +320,8 @@ ZipFile Objects
    *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
+   the new entry.
+   The archive must be open with mode ``'w'``, ``'x'`` 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`.
@@ -340,16 +343,16 @@ ZipFile Objects
       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[, compress_type])
 
    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`.
+   name, the date and time is set to the current date and time.
+   The archive must be opened with mode ``'w'``, ``'x'`` 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`.
 
    If given, *compress_type* overrides the value given for the *compression*
    parameter to the constructor for the new entry, or in the *zinfo_or_arcname*
@@ -377,7 +380,8 @@ The following data attributes are also available:
 .. attribute:: ZipFile.comment
 
    The comment text associated with the ZIP file.  If assigning a comment to a
-   :class:`ZipFile` instance created with mode 'a' or 'w', this should be a
+   :class:`ZipFile` instance created with mode ``'w'``, ``'x'`` or ``'a'``,
+   this should be a
    string no longer than 65535 bytes.  Comments longer than this will be
    truncated in the written archive when :meth:`close` is called.
 
@@ -407,8 +411,7 @@ The :class:`PyZipFile` constructor takes the same parameters as the
       archive.
 
       If the *optimize* parameter to :class:`PyZipFile` was not given or ``-1``,
-      the corresponding file is a :file:`\*.pyo` file if available, else a
-      :file:`\*.pyc` file, compiling if necessary.
+      the corresponding file is a :file:`\*.pyc` file, compiling if necessary.
 
       If the *optimize* parameter to :class:`PyZipFile` was ``0``, ``1`` or
       ``2``, only files with that optimization level (see :func:`compile`) are
@@ -571,4 +574,3 @@ Instances have the following attributes:
 .. attribute:: ZipInfo.file_size
 
    Size of the uncompressed file.
-
diff --git a/Doc/library/zipimport.rst b/Doc/library/zipimport.rst
index 2cf508b..8a5d5d1 100644
--- a/Doc/library/zipimport.rst
+++ b/Doc/library/zipimport.rst
@@ -20,10 +20,10 @@ subdirectory.  For example, the path :file:`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:`.pyc` 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
+corresponding :file:`.pyc` file, meaning that if a ZIP archive
 doesn't contain :file:`.pyc` files, importing may be rather slow.
 
 ZIP archives with an archive comment are currently not supported.
@@ -161,4 +161,3 @@ Here is an example that imports a module from a ZIP archive - note that the
    >>> import jwzthreading
    >>> jwzthreading.__file__
    'example.zip/jwzthreading.py'
-
diff --git a/Doc/make.bat b/Doc/make.bat
index 251f822..3ff91f2 100644
--- a/Doc/make.bat
+++ b/Doc/make.bat
@@ -8,9 +8,17 @@ set this=%~n0
 if "%SPHINXBUILD%" EQU "" set SPHINXBUILD=sphinx-build
 if "%PYTHON%" EQU "" set PYTHON=py
 
-if DEFINED ProgramFiles(x86) set _PRGMFLS=%ProgramFiles(x86)%
-if NOT DEFINED ProgramFiles(x86) set _PRGMFLS=%ProgramFiles%
-if "%HTMLHELP%" EQU "" set HTMLHELP=%_PRGMFLS%\HTML Help Workshop\hhc.exe
+if "%1" NEQ "htmlhelp" goto :skiphhcsearch
+if exist "%HTMLHELP%" goto :skiphhcsearch
+
+rem Search for HHC in likely places
+set HTMLHELP=
+where hhc /q && set HTMLHELP=hhc && goto :skiphhcsearch
+where /R ..\externals hhc > "%TEMP%\hhc.loc" 2> nul && set /P HTMLHELP= < "%TEMP%\hhc.loc" & del "%TEMP%\hhc.loc"
+if not exist "%HTMLHELP%" where /R "%ProgramFiles(x86)%" hhc > "%TEMP%\hhc.loc" 2> nul && set /P HTMLHELP= < "%TEMP%\hhc.loc" & del "%TEMP%\hhc.loc"
+if not exist "%HTMLHELP%" where /R "%ProgramFiles%" hhc > "%TEMP%\hhc.loc" 2> nul && set /P HTMLHELP= < "%TEMP%\hhc.loc" & del "%TEMP%\hhc.loc"
+if not exist "%HTMLHELP%" echo Cannot find HHC on PATH or in externals & exit /B 1
+:skiphhcsearch
 
 if "%DISTVERSION%" EQU "" for /f "usebackq" %%v in (`%PYTHON% tools/extensions/patchlevel.py`) do set DISTVERSION=%%v
 
@@ -36,7 +44,8 @@ if errorlevel 9009 (
     echo.
     echo.If you don't have Sphinx installed, grab it from
     echo.http://sphinx-doc.org/
-    goto end
+    popd
+    exit /B 1
 )
 
 rem Targets that do require sphinx-build and have their own label
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index dda18ba..df8b245 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1986,6 +1986,7 @@ left undefined.
 .. method:: object.__add__(self, other)
             object.__sub__(self, other)
             object.__mul__(self, other)
+            object.__matmul__(self, other)
             object.__truediv__(self, other)
             object.__floordiv__(self, other)
             object.__mod__(self, other)
@@ -2002,15 +2003,16 @@ left undefined.
       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__`.  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.
+   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__`.  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``.
@@ -2019,6 +2021,7 @@ left undefined.
 .. method:: object.__radd__(self, other)
             object.__rsub__(self, other)
             object.__rmul__(self, other)
+            object.__rmatmul__(self, other)
             object.__rtruediv__(self, other)
             object.__rfloordiv__(self, other)
             object.__rmod__(self, other)
@@ -2034,14 +2037,14 @@ left undefined.
       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*.
+   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
 
@@ -2059,6 +2062,7 @@ left undefined.
 .. method:: object.__iadd__(self, other)
             object.__isub__(self, other)
             object.__imul__(self, other)
+            object.__imatmul__(self, other)
             object.__itruediv__(self, other)
             object.__ifloordiv__(self, other)
             object.__imod__(self, other)
@@ -2070,17 +2074,17 @@ left undefined.
             object.__ior__(self, other)
 
    These methods are called to implement the augmented arithmetic assignments
-   (``+=``, ``-=``, ``*=``, ``/=``, ``//=``, ``%=``, ``**=``, ``<<=``, ``>>=``,
-   ``&=``, ``^=``, ``|=``).  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
-   assignment falls back to the normal methods.  For instance, if *x* is an
-   instance of a class with an :meth:`__iadd__` method, ``x += y`` is equivalent
-   to ``x = x.__iadd__(y)`` . Otherwise, ``x.__add__(y)`` and ``y.__radd__(x)``
-   are considered, as with the evaluation of ``x + y``. In certain situations,
-   augmented assignment can result in unexpected errors (see
-   :ref:`faq-augmented-assignment-tuple-error`), but this behavior is in
-   fact part of the data model.
+   (``+=``, ``-=``, ``*=``, ``@=``, ``/=``, ``//=``, ``%=``, ``**=``, ``<<=``,
+   ``>>=``, ``&=``, ``^=``, ``|=``).  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 assignment falls back to the normal methods.  For instance, if *x*
+   is an instance of a class with an :meth:`__iadd__` method, ``x += y`` is
+   equivalent to ``x = x.__iadd__(y)`` . Otherwise, ``x.__add__(y)`` and
+   ``y.__radd__(x)`` are considered, as with the evaluation of ``x + y``. In
+   certain situations, augmented assignment can result in unexpected errors (see
+   :ref:`faq-augmented-assignment-tuple-error`), but this behavior is in fact
+   part of the data model.
 
 
 .. method:: object.__neg__(self)
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index 1a5088a..12f9f2f 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -891,8 +891,9 @@ 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`
+   m_expr: `u_expr` | `m_expr` "*" `u_expr` | `m_expr` "@" `m_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
@@ -903,6 +904,13 @@ 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:: single: matrix multiplication
+
+The ``@`` (at) operator is intended to be used for matrix multiplication.  No
+builtin Python types implement this operator.
+
+.. versionadded:: 3.5
+
 .. index::
    exception: ZeroDivisionError
    single: division
@@ -1346,8 +1354,9 @@ precedence and have a left-to-right chaining feature as described in the
 +-----------------------------------------------+-------------------------------------+
 | ``+``, ``-``                                  | Addition and subtraction            |
 +-----------------------------------------------+-------------------------------------+
-| ``*``, ``/``, ``//``, ``%``                   | Multiplication, division, remainder |
-|                                               | [#]_                                |
+| ``*``, ``@``, ``/``, ``//``, ``%``            | Multiplication, matrix              |
+|                                               | multiplication division,            |
+|                                               | remainder [#]_                      |
 +-----------------------------------------------+-------------------------------------+
 | ``+x``, ``-x``, ``~x``                        | Positive, negative, bitwise NOT     |
 +-----------------------------------------------+-------------------------------------+
diff --git a/Doc/reference/import.rst b/Doc/reference/import.rst
index e9b7e53..dec5f8f 100644
--- a/Doc/reference/import.rst
+++ b/Doc/reference/import.rst
@@ -339,6 +339,7 @@ of what happens during the loading portion of import::
 
     module = None
     if spec.loader is not None and hasattr(spec.loader, 'create_module'):
+        # It is assumed 'exec_module' will also be defined on the loader.
         module = spec.loader.create_module(spec)
     if module is None:
         module = ModuleType(spec.name)
@@ -427,7 +428,7 @@ Module loaders may opt in to creating the module object during loading
 by implementing a :meth:`~importlib.abc.Loader.create_module` method.
 It takes one argument, the module spec, and returns the new module object
 to use during loading.  ``create_module()`` does not need to set any attributes
-on the module object.  If the loader does not define ``create_module()``, the
+on the module object.  If the method returns ``None``, the
 import machinery will create the new module itself.
 
 .. versionadded:: 3.4
@@ -459,7 +460,13 @@ import machinery will create the new module itself.
 
     * If loading fails, the loader must remove any modules it has inserted
       into :data:`sys.modules`, but it must remove **only** the failing
-      module, and only if the loader itself has loaded it explicitly.
+      module(s), and only if the loader itself has loaded the module(s)
+      explicitly.
+
+.. versionchanged:: 3.5
+   A :exc:`DeprecationWarning` is raised when ``exec_module()`` is defined but
+   ``create_module()`` is not. Starting in Python 3.6 it will be an error to not
+   define ``create_module()`` on a loader attached to a ModuleSpec.
 
 Module spec
 -----------
@@ -639,7 +646,7 @@ path entry finder that knows how to handle that particular kind of path.
 
 The default set of path entry finders implement all the semantics for finding
 modules on the file system, handling special file types such as Python source
-code (``.py`` files), Python byte code (``.pyc`` and ``.pyo`` files) and
+code (``.py`` files), Python byte code (``.pyc`` files) and
 shared libraries (e.g. ``.so`` files). When supported by the :mod:`zipimport`
 module in the standard library, the default path entry finders also handle
 loading all of these file types (other than shared libraries) from zipfiles.
@@ -753,6 +760,15 @@ hook` callables on :data:`sys.path_hooks`, then the following protocol is used
 to ask the finder for a module spec, which is then used when loading the
 module.
 
+The current working directory -- denoted by an empty string -- is handled
+slightly differently from other entries on :data:`sys.path`. First, if the
+current working directory is found to not exist, no value is stored in
+:data:`sys.path_importer_cache`. Second, the value for the current working
+directory is looked up fresh for each module lookup. Third, the path used for
+:data:`sys.path_importer_cache` and returned by
+:meth:`importlib.machinery.PathFinder.find_spec` will be the actual current
+working directory and not the empty string.
+
 Path entry finder protocol
 --------------------------
 
diff --git a/Doc/reference/lexical_analysis.rst b/Doc/reference/lexical_analysis.rst
index 2bf66b1..c673791 100644
--- a/Doc/reference/lexical_analysis.rst
+++ b/Doc/reference/lexical_analysis.rst
@@ -311,7 +311,7 @@ The Unicode category codes mentioned above stand for:
 * *Nd* - decimal numbers
 * *Pc* - connector punctuations
 * *Other_ID_Start* - explicit list of characters in `PropList.txt
-  <http://www.unicode.org/Public/6.3.0/ucd/PropList.txt>`_ to support backwards
+  <http://www.unicode.org/Public/7.0.0/ucd/PropList.txt>`_ to support backwards
   compatibility
 * *Other_ID_Continue* - likewise
 
@@ -691,7 +691,7 @@ Operators
 
 The following tokens are operators::
 
-   +       -       *       **      /       //      %
+   +       -       *       **      /       //      %      @
    <<      >>      &       |       ^       ~
    <       >       <=      >=      ==      !=
 
@@ -707,7 +707,7 @@ The following tokens serve as delimiters in the grammar::
 
    (       )       [       ]       {       }
    ,       :       .       ;       @       =       ->
-   +=      -=      *=      /=      //=     %=
+   +=      -=      *=      /=      //=     %=      @=
    &=      |=      ^=      >>=     <<=     **=
 
 The period can also occur in floating-point and imaginary literals.  A sequence
@@ -728,4 +728,4 @@ occurrence outside string literals and comments is an unconditional error::
 
 .. rubric:: Footnotes
 
-.. [#] http://www.unicode.org/Public/6.3.0/ucd/NameAliases.txt
+.. [#] http://www.unicode.org/Public/7.0.0/ucd/NameAliases.txt
diff --git a/Doc/reference/simple_stmts.rst b/Doc/reference/simple_stmts.rst
index 8946b4f..5f60540 100644
--- a/Doc/reference/simple_stmts.rst
+++ b/Doc/reference/simple_stmts.rst
@@ -281,7 +281,7 @@ operation and an assignment statement:
 .. productionlist::
    augmented_assignment_stmt: `augtarget` `augop` (`expression_list` | `yield_expression`)
    augtarget: `identifier` | `attributeref` | `subscription` | `slicing`
-   augop: "+=" | "-=" | "*=" | "/=" | "//=" | "%=" | "**="
+   augop: "+=" | "-=" | "*=" | "@=" | "/=" | "//=" | "%=" | "**="
         : | ">>=" | "<<=" | "&=" | "^=" | "|="
 
 (See section :ref:`primaries` for the syntax definitions of the last three
diff --git a/Doc/tools/extensions/pyspecific.py b/Doc/tools/extensions/pyspecific.py
index 64a5665..9b78184 100644
--- a/Doc/tools/extensions/pyspecific.py
+++ b/Doc/tools/extensions/pyspecific.py
@@ -34,7 +34,7 @@ import suspicious
 
 
 ISSUE_URI = 'https://bugs.python.org/issue%s'
-SOURCE_URI = 'https://hg.python.org/cpython/file/3.4/%s'
+SOURCE_URI = 'https://hg.python.org/cpython/file/default/%s'
 
 # monkey-patch reST parser to disable alphabetic and roman enumerated lists
 from docutils.parsers.rst.states import Body
diff --git a/Doc/tools/susp-ignored.csv b/Doc/tools/susp-ignored.csv
index 48653af8..5eaa09a 100644
--- a/Doc/tools/susp-ignored.csv
+++ b/Doc/tools/susp-ignored.csv
@@ -122,6 +122,8 @@ library/ipaddress,,:db8,>>> ipaddress.IPv6Address('2001:db8::1000')
 library/ipaddress,,::,>>> ipaddress.IPv6Address('2001:db8::1000')
 library/ipaddress,,:db8,IPv6Address('2001:db8::1000')
 library/ipaddress,,::,IPv6Address('2001:db8::1000')
+library/ipaddress,,:db8,">>> ipaddress.ip_address(""2001:db8::1"").reverse_pointer"
+library/ipaddress,,::,">>> ipaddress.ip_address(""2001:db8::1"").reverse_pointer"
 library/ipaddress,,::,"""::abc:7:def"""
 library/ipaddress,,:def,"""::abc:7:def"""
 library/ipaddress,,::,::FFFF/96
@@ -136,12 +138,9 @@ library/ipaddress,,:db00,2001:db00::0/ffff:ff00::
 library/ipaddress,,::,2001:db00::0/ffff:ff00::
 library/itertools,,:step,elements from seq[start:stop:step]
 library/itertools,,:stop,elements from seq[start:stop:step]
-library/linecache,,:sys,"sys:x:3:3:sys:/dev:/bin/sh"
 library/logging.handlers,,:port,host:port
 library/mmap,,:i2,obj[i1:i2]
 library/multiprocessing,,`,# Add more tasks using `put()`
-library/multiprocessing,,`,">>> l._callmethod('__getitem__', (20,))     # equiv to `l[20]`"
-library/multiprocessing,,`,">>> l._callmethod('__getslice__', (2, 7))   # equiv to `l[2:7]`"
 library/multiprocessing,,:queue,">>> QueueManager.register('get_queue', callable=lambda:queue)"
 library/multiprocessing,,`,# register the Foo class; make `f()` and `g()` accessible via proxy
 library/multiprocessing,,`,# register the Foo class; make `g()` and `_h()` accessible via proxy
@@ -179,8 +178,6 @@ library/ssl,,:MyState,State or Province Name (full name) [Some-State]:MyState
 library/ssl,,:ops,Email Address []:ops@myserver.mygroup.myorganization.com
 library/ssl,,:Some,"Locality Name (eg, city) []:Some City"
 library/ssl,,:US,Country Name (2 letter code) [AU]:US
-library/stdtypes,,::,>>> a[::-1].tolist()
-library/stdtypes,,::,>>> a[::2].tolist()
 library/stdtypes,,:end,s[start:end]
 library/stdtypes,,::,>>> hash(v[::-2]) == hash(b'abcefg'[::-2])
 library/stdtypes,,:len,s[len(s):len(s)]
@@ -256,6 +253,11 @@ whatsnew/2.4,,:System,
 whatsnew/2.5,,:memory,:memory:
 whatsnew/2.5,,:step,[start:stop:step]
 whatsnew/2.5,,:stop,[start:stop:step]
+whatsnew/2.7,,::,"ParseResult(scheme='http', netloc='[1080::8:800:200C:417A]',"
+whatsnew/2.7,,::,>>> urlparse.urlparse('http://[1080::8:800:200C:417A]/foo')
+whatsnew/2.7,,:Sunday,'2009:4:Sunday'
+whatsnew/2.7,,:Cookie,"export PYTHONWARNINGS=all,error:::Cookie:0"
+whatsnew/2.7,,::,"export PYTHONWARNINGS=all,error:::Cookie:0"
 whatsnew/3.2,,:affe,"netloc='[dead:beef:cafe:5417:affe:8FA3:deaf:feed]',"
 whatsnew/3.2,,:affe,>>> urllib.parse.urlparse('http://[dead:beef:cafe:5417:affe:8FA3:deaf:feed]/foo/')
 whatsnew/3.2,,:beef,"netloc='[dead:beef:cafe:5417:affe:8FA3:deaf:feed]',"
@@ -271,14 +273,20 @@ whatsnew/3.2,,:feed,>>> urllib.parse.urlparse('http://[dead:beef:cafe:5417:affe:
 whatsnew/3.2,,:gz,">>> with tarfile.open(name='myarchive.tar.gz', mode='w:gz') as tf:"
 whatsnew/3.2,,:location,zope9-location = ${zope9:location}
 whatsnew/3.2,,:prefix,zope-conf = ${custom:prefix}/etc/zope.conf
-whatsnew/changelog,,:platform,:platform:
 whatsnew/changelog,,:gz,": TarFile opened with external fileobj and ""w:gz"" mode didn't"
-whatsnew/changelog,,:PythonCmd,"With Tk < 8.5 _tkinter.c:PythonCmd() raised UnicodeDecodeError, caused"
-whatsnew/changelog,,::,": Fix FTP tests for IPv6, bind to ""::1"" instead of ""localhost""."
 whatsnew/changelog,,::,": Use ""127.0.0.1"" or ""::1"" instead of ""localhost"" as much as"
-whatsnew/changelog,,:password,user:password
-whatsnew/2.7,780,:Sunday,'2009:4:Sunday'
-whatsnew/2.7,907,::,"export PYTHONWARNINGS=all,error:::Cookie:0"
-whatsnew/2.7,907,:Cookie,"export PYTHONWARNINGS=all,error:::Cookie:0"
-whatsnew/2.7,1657,::,>>> urlparse.urlparse('http://[1080::8:800:200C:417A]/foo')
-whatsnew/2.7,1657,::,"ParseResult(scheme='http', netloc='[1080::8:800:200C:417A]',"
+library/tarfile,149,:xz,'x:xz'
+library/xml.etree.elementtree,290,:sometag,prefix:sometag
+library/xml.etree.elementtree,301,:fictional,"<actors xmlns:fictional=""http://characters.example.com"""
+library/xml.etree.elementtree,301,:character,<fictional:character>Lancelot</fictional:character>
+library/xml.etree.elementtree,301,:character,<fictional:character>Archie Leach</fictional:character>
+library/xml.etree.elementtree,301,:character,<fictional:character>Sir Robin</fictional:character>
+library/xml.etree.elementtree,301,:character,<fictional:character>Gunther</fictional:character>
+library/xml.etree.elementtree,301,:character,<fictional:character>Commander Clement</fictional:character>
+library/xml.etree.elementtree,332,:actor,"for actor in root.findall('real_person:actor', ns):"
+library/xml.etree.elementtree,332,:name,"name = actor.find('real_person:name', ns)"
+library/xml.etree.elementtree,332,:character,"for char in actor.findall('role:character', ns):"
+library/zipapp,31,:main,"$ python -m zipapp myapp -m ""myapp:main"""
+library/zipapp,82,:fn,"argument should have the form ""pkg.mod:fn"", where ""pkg.mod"" is a"
+library/zipapp,155,:callable,"""pkg.module:callable"" and the archive will be run by importing"
+library/stdtypes,3720,::,>>> m[::2].tolist()
diff --git a/Doc/tools/templates/indexsidebar.html b/Doc/tools/templates/indexsidebar.html
index abdf070..78e9c4f 100644
--- a/Doc/tools/templates/indexsidebar.html
+++ b/Doc/tools/templates/indexsidebar.html
@@ -3,8 +3,7 @@
 <h3>Docs for other versions</h3>
 <ul>
   <li><a href="https://docs.python.org/2.7/">Python 2.7 (stable)</a></li>
-  <li><a href="https://docs.python.org/3.3/">Python 3.3 (stable)</a></li>
-  <li><a href="https://docs.python.org/3.5/">Python 3.5 (in development)</a></li>
+  <li><a href="https://docs.python.org/3.4/">Python 3.4 (stable)</a></li>
   <li><a href="https://www.python.org/doc/versions/">Old versions</a></li>
 </ul>
 
diff --git a/Doc/tutorial/appendix.rst b/Doc/tutorial/appendix.rst
index 8670efc..67262a1 100644
--- a/Doc/tutorial/appendix.rst
+++ b/Doc/tutorial/appendix.rst
@@ -40,7 +40,7 @@ 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 python3.4
+   #!/usr/bin/env python3.5
 
 (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
@@ -107,7 +107,7 @@ of your user site-packages directory.  Start Python and run this code::
 
    >>> import site
    >>> site.getusersitepackages()
-   '/home/user/.local/lib/python3.4/site-packages'
+   '/home/user/.local/lib/python3.5/site-packages'
 
 Now you can create a file named :file:`usercustomize.py` in that directory and
 put anything you want in it.  It will affect every invocation of Python, unless
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index 1ea299f..a2031ed 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -73,10 +73,11 @@ objects:
    Return the number of times *x* appears in the list.
 
 
-.. method:: list.sort()
+.. method:: list.sort(key=None, reverse=False)
    :noindex:
 
-   Sort the items of the list in place.
+   Sort the items of the list in place (the arguments can be used for sort
+   customization, see :func:`sorted` for their explanation).
 
 
 .. method:: list.reverse()
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
index 8051634..d5789a6 100644
--- a/Doc/tutorial/interpreter.rst
+++ b/Doc/tutorial/interpreter.rst
@@ -10,13 +10,13 @@ Using the Python Interpreter
 Invoking the Interpreter
 ========================
 
-The Python interpreter is usually installed as :file:`/usr/local/bin/python3.4`
+The Python interpreter is usually installed as :file:`/usr/local/bin/python3.5`
 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:
 
 .. code-block:: text
 
-   python3.4
+   python3.5
 
 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
@@ -24,11 +24,11 @@ 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:\\Python34`, though you can change this when you're running the
+:file:`C:\\Python35`, 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:\python34
+   set path=%path%;C:\python35
 
 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
@@ -96,8 +96,8 @@ 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::
 
-   $ python3.4
-   Python 3.4 (default, Mar 16 2014, 09:25:04)
+   $ python3.5
+   Python 3.5 (default, Sep 16 2015, 09:25:04)
    [GCC 4.8.2] on linux
    Type "help", "copyright", "credits" or "license" for more information.
    >>>
diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst
index fd361ae..9ae64b0 100644
--- a/Doc/tutorial/modules.rst
+++ b/Doc/tutorial/modules.rst
@@ -216,15 +216,15 @@ Some tips for experts:
   statements, the ``-OO`` switch removes both assert statements and __doc__
   strings.  Since some programs may rely on having these available, you should
   only use this option if you know what you're doing.  "Optimized" modules have
-  a .pyo rather than a .pyc suffix and are usually smaller.  Future releases may
+  an ``opt-`` tag and are usually smaller.  Future releases may
   change the effects of optimization.
 
-* A program doesn't run any faster when it is read from a ``.pyc`` or ``.pyo``
+* A program doesn't run any faster when it is read from a ``.pyc``
   file than when it is read from a ``.py`` file; the only thing that's faster
-  about ``.pyc`` or ``.pyo`` files is the speed with which they are loaded.
+  about ``.pyc`` files is the speed with which they are loaded.
 
-* The module :mod:`compileall` can create .pyc files (or .pyo files when
-  :option:`-O` is used) for all modules in a directory.
+* The module :mod:`compileall` can create .pyc files for all modules in a
+  directory.
 
 * There is more detail on this process, including a flow chart of the
   decisions, in PEP 3147.
@@ -548,4 +548,3 @@ modules found in a package.
 .. [#] In fact function definitions are also 'statements' that are 'executed'; the
    execution of a module-level function definition enters the function name in
    the module's global symbol table.
-
diff --git a/Doc/tutorial/stdlib.rst b/Doc/tutorial/stdlib.rst
index d71598e..598859d 100644
--- a/Doc/tutorial/stdlib.rst
+++ b/Doc/tutorial/stdlib.rst
@@ -15,7 +15,7 @@ operating system::
 
    >>> import os
    >>> os.getcwd()      # Return the current working directory
-   'C:\\Python34'
+   'C:\\Python35'
    >>> os.chdir('/server/accesslogs')   # Change current working directory
    >>> os.system('mkdir today')   # Run the command mkdir in the system shell
    0
diff --git a/Doc/tutorial/stdlib2.rst b/Doc/tutorial/stdlib2.rst
index c0197ea..f7d2a0a 100644
--- a/Doc/tutorial/stdlib2.rst
+++ b/Doc/tutorial/stdlib2.rst
@@ -18,7 +18,7 @@ abbreviated displays of large or deeply nested containers::
 
    >>> import reprlib
    >>> reprlib.repr(set('supercalifragilisticexpialidocious'))
-   "set(['a', 'c', 'd', 'e', 'f', 'g', ...])"
+   "{'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.
@@ -277,7 +277,7 @@ applications include caching objects that are expensive to create::
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
        d['primary']                # entry was automatically removed
-     File "C:/python34/lib/weakref.py", line 46, in __getitem__
+     File "C:/python35/lib/weakref.py", line 46, in __getitem__
        o = self.data[key]()
    KeyError: 'primary'
 
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 4017ce8..701c624 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -190,13 +190,16 @@ Miscellaneous options
 
 .. cmdoption:: -b
 
-   Issue a warning when comparing str and bytes. Issue an error when the
+   Issue a warning when comparing :class:`bytes` or :class:`bytearray` with
+   :class:`str` or :class:`bytes` with :class:`int`.  Issue an error when the
    option is given twice (:option:`-bb`).
 
+   .. versionchanged: 3.5
+      Affects comparisons of :class:`bytes` with :class:`int`.
 
 .. cmdoption:: -B
 
-   If given, Python won't try to write ``.pyc`` or ``.pyo`` files on the
+   If given, Python won't try to write ``.pyc`` files on the
    import of source modules.  See also :envvar:`PYTHONDONTWRITEBYTECODE`.
 
 
diff --git a/Doc/using/venv-create.inc b/Doc/using/venv-create.inc
index 45bdd5a..02bcbee 100644
--- a/Doc/using/venv-create.inc
+++ b/Doc/using/venv-create.inc
@@ -21,11 +21,11 @@ subdirectory (on Windows, this is ``Lib\site-packages``).
 On Windows, you may have to invoke the ``pyvenv`` script as follows, if you
 don't have the relevant PATH and PATHEXT settings::
 
-    c:\Temp>c:\Python34\python c:\Python34\Tools\Scripts\pyvenv.py myenv
+    c:\Temp>c:\Python35\python c:\Python35\Tools\Scripts\pyvenv.py myenv
 
 or equivalently::
 
-    c:\Temp>c:\Python34\python -m venv myenv
+    c:\Temp>c:\Python35\python -m venv myenv
 
 The command, if run with ``-h``, will show the available options::
 
diff --git a/Doc/using/win_installer.png b/Doc/using/win_installer.png
new file mode 100644
index 0000000..4696bb2
--- /dev/null
+++ b/Doc/using/win_installer.png
diff --git a/Doc/using/windows.rst b/Doc/using/windows.rst
index c05f72a..7113dfa 100644
--- a/Doc/using/windows.rst
+++ b/Doc/using/windows.rst
@@ -7,6 +7,7 @@
 *************************
 
 .. sectionauthor:: Robert Lehmann <lehmannro@gmail.com>
+.. sectionauthor:: Steve Dower <steve.dower@microsoft.com>
 
 This document aims to give an overview of Windows-specific behaviour you should
 know about when using Python on Microsoft Windows.
@@ -19,10 +20,172 @@ know about when using Python on Microsoft Windows.
 Installing Python
 =================
 
-Unlike most Unix systems and services, Windows does not require Python natively
-and thus does not pre-install a version of Python.  However, the CPython team
+Unlike most Unix systems and services, Windows does not include a system
+supported installation of Python. To make Python available, the CPython team
 has compiled Windows installers (MSI packages) with every `release
-<https://www.python.org/download/releases/>`_ for many years.
+<https://www.python.org/download/releases/>`_ for many years. These installers
+are primarily intended to add a system-wide installation of Python, with the
+core interpreter and library being shared by all application. Non-shared
+layouts of the Python interpreter may also be created with the same installer,
+however, the released installer is not intended for embedding in other
+installers.
+
+Installation Steps
+------------------
+
+Four Python 3.5 installers are available for download - two each for the 32-bit
+and 64-bit versions of the interpreter. The *web installer* is a small initial
+download, and it will automatically download the required components as
+necessary. The *offline installer* includes the components necessary for a
+default installation and only requires an internet connection for optional
+features. See :ref:`install-layout-option` for other ways to avoid downloading
+during installation.
+
+After starting the installer, one of three options may be selected:
+
+.. image:: win_installer.png
+
+If you select "Install for All Users":
+
+* You may be required to provide administrative credentials or approval
+* Python will be installed into your Program Files directory
+* The :ref:`launcher` will be installed into your Windows directory
+* The standard library, test suite, launcher and pip will be installed
+* After installation, the standard library will be pre-compiled to bytecode
+* If selected, the install directory will be added to :envvar:`PATH`
+
+If you select "Install Just for Me":
+
+* You will *not* need to be an administrator
+* Python will be installed into your user directory
+* The :ref:`launcher` will *also* be installed into your user directory
+* The standard library, test suite, launcher and pip will be installed
+* If selected, the install directory will be added to :envvar:`PATH`
+
+Selecting "Customize installation" will allow you to select the features to
+install, the installation location and other options or post-install actions.
+To install debugging symbols or binaries, you will need to use this option.
+
+.. _install-quiet-option:
+
+Installing Without UI
+---------------------
+
+All of the options available in the installer UI can also be specified from the
+command line, allowing scripted installers to replicate an installation on many
+machines without user interaction.  These options may also be set without
+suppressing the UI in order to change some of the defaults.
+
+To completely hide the installer UI and install Python silently, pass the
+``/quiet`` (``/q``) option. To skip past the user interaction but still display
+progress and errors, pass the ``/passive`` (``/p``) option. The ``/uninstall``
+option may be passed to immediately begin removing Python - no prompt will be
+displayed.
+
+All other options are passed as ``name=value``, where the value is usually
+``0`` to disable a feature, ``1`` to enable a feature, or a path. The full list
+of available options is shown below.
+
++---------------------------+--------------------------------------+--------------------------+
+| Name                      | Description                          | Default                  |
++===========================+======================================+==========================+
+| InstallAllUsers           | Perform a system-wide installation.  | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| TargetDir                 | The installation directory           | Selected based on        |
+|                           |                                      | InstallAllUsers          |
++---------------------------+--------------------------------------+--------------------------+
+| DefaultAllUsersTargetDir  | The default installation directory   | :file:`%ProgramFiles%\\\ |
+|                           | for all-user installs                | Python X.Y` or :file:`\  |
+|                           |                                      | %ProgramFiles(x86)%\\\   |
+|                           |                                      | Python X.Y`              |
++---------------------------+--------------------------------------+--------------------------+
+| DefaultJustForMeTargetDir | The default install directory for    | :file:`%LocalAppData%\\\ |
+|                           | just-for-me installs                 | Programs\\PythonXY` or   |
+|                           |                                      | :file:`%LocalAppData%\\\ |
+|                           |                                      | Programs\\PythonXY-32`   |
++---------------------------+--------------------------------------+--------------------------+
+| DefaultCustomTargetDir    | The default custom install directory | (empty)                  |
+|                           | displayed in the UI                  |                          |
++---------------------------+--------------------------------------+--------------------------+
+| AssociateFiles            | Create file associations if the      | 1                        |
+|                           | launcher is also installed.          |                          |
++---------------------------+--------------------------------------+--------------------------+
+| CompileAll                | Compile all ``.py`` files to         | 0                        |
+|                           | ``.pyc``.                            |                          |
++---------------------------+--------------------------------------+--------------------------+
+| PrependPath               | Add install and Scripts directories  | 0                        |
+|                           | tho :envvar:`PATH` and ``.PY`` to    |                          |
+|                           | :envvar:`PATHEXT`                    |                          |
++---------------------------+--------------------------------------+--------------------------+
+| Include_doc               | Install Python manual                | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_debug             | Install debug binaries               | 0                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_dev               | Install developer headers and        | 1                        |
+|                           | libraries                            |                          |
++---------------------------+--------------------------------------+--------------------------+
+| Include_exe               | Install :file:`python.exe` and       | 1                        |
+|                           | related files                        |                          |
++---------------------------+--------------------------------------+--------------------------+
+| Include_launcher          | Install :ref:`launcher`.             | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_lib               | Install standard library and         | 1                        |
+|                           | extension modules                    |                          |
++---------------------------+--------------------------------------+--------------------------+
+| Include_pip               | Install bundled pip and setuptools   | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_symbols           | Install debugging symbols (`*`.pdb)  | 0                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_tcltk             | Install Tcl/Tk support and IDLE      | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_test              | Install standard library test suite  | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| Include_tools             | Install utility scripts              | 1                        |
++---------------------------+--------------------------------------+--------------------------+
+| SimpleInstall             | Disable most install UI              | 0                        |
++---------------------------+--------------------------------------+--------------------------+
+
+For example, to silently install a default, system-wide Python installation,
+you could use the following command (from an elevated command prompt)::
+
+    python-3.5.0.exe /quiet InstallAllUsers=1 PrependPath=1 Include_test=0
+
+To allow users to easily install a personal copy of Python without the test
+suite, you could provide a shortcut with the following command::
+
+    python-3.5.0.exe /passive InstallAllUsers=0 Include_launcher=0 Include_test=0 SimpleInstall=1
+
+(Note that omitting the launcher also omits file associations, and is only
+recommended for per-user installs when there is also a system-wide installation
+that included the launcher.)
+
+.. _install-layout-option:
+
+Installing Without Downloading
+------------------------------
+
+As some features of Python are not included in the initial installer download,
+selecting those features may require an internet connection.  To avoid this
+need, all possible components may be downloaded on-demand to create a complete
+*layout* that will no longer require an internet connection regardless of the
+selected features. Note that this download may be bigger than required, but
+where a large number of installations are going to be performed it is very
+useful to have a locally cached copy.
+
+Execute the following command from Command Prompt to download all possible
+required files.  Remember to substitute ``python-3.5.0.exe`` for the actual
+name of your installer, and to create layouts in their own directories to
+avoid collisions between files with the same name.
+
+::
+
+    python-3.5.0.exe /layout [optional target directory]
+
+You may also specify the ``/quiet`` option to hide the progress display.
+
+
+Other Platforms
+---------------
 
 With ongoing development of Python, some platforms that used to be supported
 earlier are no longer supported (due to the lack of users or developers).
@@ -66,19 +229,31 @@ key features:
 `ActivePython <http://www.activestate.com/activepython/>`_
     Installer with multi-platform compatibility, documentation, PyWin32
 
-`Enthought Python Distribution <https://www.enthought.com/products/epd/>`_
-    Popular modules (such as PyWin32) with their respective documentation, tool
-    suite for building extensible Python applications
+`Anaconda <http://www.continuum.io/downloads/>`_
+    Popular scientific modules (such as numpy, scipy and pandas) and the
+    ``conda`` package manager.
+
+`Canopy <https://www.enthought.com/products/canopy/>`_
+    A "comprehensive Python analysis environment" with editors and other
+    development tools.
 
-Notice that these packages are likely to install *older* versions of Python.
+`WinPython <https://winpython.github.io/>`_
+    Windows-specific distribution with prebuilt scientific packages and
+    tools for building packages.
+
+Note that these packages may not include the latest versions of Python or
+other libraries, and are not maintained or supported by the core Python team.
 
 
 
 Configuring Python
 ==================
 
-In order to run Python flawlessly, you might have to change certain environment
-settings in Windows.
+To run Python conveniently from a command prompt, you might consider changing
+some default environment variables in Windows.  While the installer provides an
+option to configure the PATH and PATHEXT variables for you, this is only
+reliable for a single, system-wide installation.  If you regularly use multiple
+versions of Python, consider using the :ref:`launcher`.
 
 
 .. _setting-envvars:
@@ -86,163 +261,86 @@ settings in Windows.
 Excursus: Setting environment variables
 ---------------------------------------
 
-Windows has a built-in dialog for changing environment variables (following
-guide applies to XP classical view): Right-click the icon for your machine
-(usually located on your Desktop and called "My Computer") and choose
-:menuselection:`Properties` there.  Then, open the :guilabel:`Advanced` tab
-and click the :guilabel:`Environment Variables` button.
+Windows allows environment variables to be configured permanently at both the
+User level and the System level, or temporarily in a command prompt.
+
+To temporarily set environment variables, open Command Prompt and use the
+:command:`set` command::
 
-In short, your path is:
+    C:\>set PATH=C:\Program Files\Python 3.5;%PATH%
+    C:\>set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib
+    C:\>python
 
-    :menuselection:`My Computer
-    --> Properties
-    --> Advanced
-    --> Environment Variables`
+These changes will apply to any further commands executed in that console, and
+will be inherited by any applications started from the console.
 
+Including the variable name within percent signs will expand to the existing
+value, allowing you to add your new value at either the start or the end.
+Modifying :envvar:`PATH` by adding the directory containing
+:program:`python.exe` to the start is a common way to ensure the correct version
+of Python is launched.
+
+To permanently modify the default environment variables, click Start and search
+for 'edit environment variables', or open System properties, :guilabel:`Advanced
+system settings` and click the :guilabel:`Environment Variables` button.
 In this dialog, you can add or modify User and System variables. To change
 System variables, you need non-restricted access to your machine
 (i.e. Administrator rights).
 
-Another way of adding variables to your environment is using the :command:`set`
-command::
-
-    set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib
-
-To make this setting permanent, you could add the corresponding command line to
-your :file:`autoexec.bat`. :program:`msconfig` is a graphical interface to this
-file.
+.. note::
 
-Viewing environment variables can also be done more straight-forward: The
-command prompt will expand strings wrapped into percent signs automatically::
+    Windows will concatenate User variables *after* System variables, which may
+    cause unexpected results when modifying :envvar:`PATH`.
 
-    echo %PATH%
-
-Consult :command:`set /?` for details on this behaviour.
+    The :envvar:`PYTHONPATH` variable is used by all versions of Python 2 and
+    Python 3, so you should not permanently configure this variable unless it
+    only includes code that is compatible all of your installed Python
+    versions.
 
 .. seealso::
 
-   http://support.microsoft.com/kb/100843
+    http://support.microsoft.com/kb/100843
       Environment variables in Windows NT
 
-   http://support.microsoft.com/kb/310519
+    http://technet.microsoft.com/en-us/library/cc754250.aspx
+      The SET command, for temporarily modifying environment variables
+
+    http://technet.microsoft.com/en-us/library/cc755104.aspx
+      The SETX command, for permanently modifying environment variables
+
+    http://support.microsoft.com/kb/310519
       How To Manage Environment Variables in Windows XP
 
-   http://www.chem.gla.ac.uk/~louis/software/faq/q1.html
+    http://www.chem.gla.ac.uk/~louis/software/faq/q1.html
       Setting Environment variables, Louis J. Farrugia
 
-
 .. _windows-path-mod:
 
 Finding the Python executable
 -----------------------------
 
-.. versionchanged:: 3.3
+.. versionchanged:: 3.5
 
 Besides using the automatically created start menu entry for the Python
-interpreter, you might want to start Python in the command prompt. As of
-Python 3.3, the installer has an option to set that up for you.
-
-At the "Customize Python 3.3" screen, an option called
-"Add python.exe to search path" can be enabled to have the installer place
-your installation into the :envvar:`%PATH%`. This allows you to type
-:command:`python` to run the interpreter. Thus, you can also execute your
+interpreter, you might want to start Python in the command prompt. The
+installer for Python 3.5 and later has an option to set that up for you.
+
+On the first page of the installer, an option labelled "Add Python 3.5 to
+PATH" can be selected to have the installer add the install location into the
+:envvar:`PATH`.  The location of the :file:`Scripts\\` folder is also added.
+This allows you to type :command:`python` to run the interpreter, and
+:command:`pip` or . Thus, you can also execute your
 scripts with command line options, see :ref:`using-on-cmdline` documentation.
 
 If you don't enable this option at install time, you can always re-run the
-installer to choose it.
-
-The alternative is manually modifying the :envvar:`%PATH%` using the
-directions in :ref:`setting-envvars`. You need to set your :envvar:`%PATH%`
-environment variable to include the directory of your Python distribution,
-delimited by a semicolon from other entries. An example variable could look
-like this (assuming the first two entries are Windows' default)::
-
-    C:\WINDOWS\system32;C:\WINDOWS;C:\Python33
-
-
-Finding modules
----------------
-
-Python usually stores its library (and thereby your site-packages folder) in the
-installation directory.  So, if you had installed Python to
-:file:`C:\\Python\\`, the default library would reside in
-:file:`C:\\Python\\Lib\\` and third-party modules should be stored in
-:file:`C:\\Python\\Lib\\site-packages\\`.
-
-This is how :data:`sys.path` is populated on Windows:
-
-* An empty entry is added at the start, which corresponds to the current
-  directory.
-
-* If the environment variable :envvar:`PYTHONPATH` exists, as described in
-  :ref:`using-on-envvars`, its entries are added next.  Note that on Windows,
-  paths in this variable must be separated by semicolons, to distinguish them
-  from the colon used in drive identifiers (``C:\`` etc.).
-
-* Additional "application paths" can be added in the registry as subkeys of
-  :samp:`\\SOFTWARE\\Python\\PythonCore\\{version}\\PythonPath` under both the
-  ``HKEY_CURRENT_USER`` and ``HKEY_LOCAL_MACHINE`` hives.  Subkeys which have
-  semicolon-delimited path strings as their default value will cause each path
-  to be added to :data:`sys.path`.  (Note that all known installers only use
-  HKLM, so HKCU is typically empty.)
-
-* If the environment variable :envvar:`PYTHONHOME` is set, it is assumed as
-  "Python Home".  Otherwise, the path of the main Python executable is used to
-  locate a "landmark file" (``Lib\os.py``) to deduce the "Python Home".  If a
-  Python home is found, the relevant sub-directories added to :data:`sys.path`
-  (``Lib``, ``plat-win``, etc) are based on that folder.  Otherwise, the core
-  Python path is constructed from the PythonPath stored in the registry.
-
-* If the Python Home cannot be located, no :envvar:`PYTHONPATH` is specified in
-  the environment, and no registry entries can be found, a default path with
-  relative entries is used (e.g. ``.\Lib;.\plat-win``, etc).
-
-The end result of all this is:
-
-* When running :file:`python.exe`, or any other .exe in the main Python
-  directory (either an installed version, or directly from the PCbuild
-  directory), the core path is deduced, and the core paths in the registry are
-  ignored.  Other "application paths" in the registry are always read.
-
-* When Python is hosted in another .exe (different directory, embedded via COM,
-  etc), the "Python Home" will not be deduced, so the core path from the
-  registry is used.  Other "application paths" in the registry are always read.
-
-* If Python can't find its home and there is no registry (eg, frozen .exe, some
-  very strange installation setup) you get a path with some default, but
-  relative, paths.
-
-
-Executing scripts
------------------
-
-As of Python 3.3, Python includes a launcher which facilitates running Python
-scripts. See :ref:`launcher` for more information.
-
-Executing scripts without the Python launcher
----------------------------------------------
-
-Without the Python launcher installed, Python scripts (files with the extension
-``.py``) will be executed by :program:`python.exe` by default.  This executable
-opens a terminal, which stays open even if the program uses a GUI.  If you do
-not want this to happen, use the extension ``.pyw`` which will cause the script
-to be executed by :program:`pythonw.exe` by default (both executables are
-located in the top-level of your Python installation directory).  This
-suppresses the terminal window on startup.
-
-You can also make all ``.py`` scripts execute with :program:`pythonw.exe`,
-setting this through the usual facilities, for example (might require
-administrative rights):
-
-#. Launch a command prompt.
-#. Associate the correct file group with ``.py`` scripts::
-
-      assoc .py=Python.File
-
-#. Redirect all Python files to the new executable::
-
-      ftype Python.File=C:\Path\to\pythonw.exe "%1" %*
+installer, select Modify, and enable it.  Alternatively, you can manually
+modify the :envvar:`PATH` using the directions in :ref:`setting-envvars`.  You
+need to set your :envvar:`PATH` environment variable to include the directory
+of your Python installation, delimited by a semicolon from other entries.  An
+example variable could look like this (assuming the first two entries already
+existed)::
 
+    C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files\Python 3.5
 
 .. _launcher:
 
@@ -251,21 +349,26 @@ Python Launcher for Windows
 
 .. versionadded:: 3.3
 
-The Python launcher for Windows is a utility which aids in the location and
-execution of different Python versions.  It allows scripts (or the
+The Python launcher for Windows is a utility which aids in locating and
+executing of different Python versions.  It allows scripts (or the
 command-line) to indicate a preference for a specific Python version, and
 will locate and execute that version.
 
+Unlike the :envvar:`PATH` variable, the launcher will correctly select the most
+appropriate version of Python. It will prefer per-user installations over
+system-wide ones, and orders by language version rather than using the most
+recently installed version.
+
 Getting started
 ---------------
 
 From the command-line
 ^^^^^^^^^^^^^^^^^^^^^
 
-You should ensure the launcher is on your PATH - depending on how it was
-installed it may already be there, but check just in case it is not.
-
-From a command-prompt, execute the following command:
+System-wide installations of Python 3.3 and later will put the launcher on your
+:envvar:`PATH`. The launcher is compatible with all available versions of
+Python, so it does not matter which version is installed. To check that the
+launcher is available, execute the following command in Command Prompt:
 
 ::
 
@@ -291,6 +394,28 @@ If you have a Python 3.x installed, try the command:
 
 You should find the latest version of Python 3.x starts.
 
+If you see the following error, you do not have the launcher installed:
+
+::
+
+  'py' is not recognized as an internal or external command,
+  operable program or batch file.
+
+Per-user installations of Python do not add the launcher to :envvar:`PATH`
+unless the option was selected on installation.
+
+Virtual environments
+^^^^^^^^^^^^^^^^^^^^
+
+.. versionadded:: 3.5
+
+If the launcher is run with no explicit Python version specification, and a
+virtual environment (created with the standard library :mod:`venv` module or
+the external ``virtualenv`` tool) active, the launcher will run the virtual
+environment's interpreter rather than the global one.  To run the global
+interpreter, either deactivate the virtual environment, or explicitly specify
+the global Python version.
+
 From a script
 ^^^^^^^^^^^^^
 
@@ -326,7 +451,7 @@ From file associations
 ^^^^^^^^^^^^^^^^^^^^^^
 
 The launcher should have been associated with Python files (i.e. ``.py``,
-``.pyw``, ``.pyc``, ``.pyo`` files) when it was installed.  This means that
+``.pyw``, ``.pyc`` files) when it was installed.  This means that
 when you double-click on one of these files from Windows explorer the launcher
 will be used, and therefore you can use the same facilities described above to
 have the script specify the version which should be used.
@@ -365,6 +490,16 @@ be used by the launcher without modification.  If you are writing a new script
 on Windows which you hope will be useful on Unix, you should use one of the
 shebang lines starting with ``/usr``.
 
+Any of the above virtual commands can be suffixed with an explicit version
+(either just the major version, or the major and minor version) - for example
+``/usr/bin/python2.7`` - which will cause that specific version to be located
+and used.
+
+The ``/usr/bin/env`` form of shebang line has one further special property.
+Before looking for installed Python interpreters, this form will search the
+executable :envvar:`PATH` for a Python executable. This corresponds to the
+behaviour of the Unix ``env`` program, which performs a :envvar:`PATH` search.
+
 Arguments in shebang lines
 --------------------------
 
@@ -383,17 +518,16 @@ Customization
 Customization via INI files
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-    Two .ini files will be searched by the launcher - ``py.ini`` in the
-    current user's "application data" directory (i.e. the directory returned
-    by calling the Windows function SHGetFolderPath with CSIDL_LOCAL_APPDATA)
-    and ``py.ini`` in the same directory as the launcher.  The same .ini
-    files are used for both the 'console' version of the launcher (i.e.
-    py.exe) and for the 'windows' version (i.e. pyw.exe)
+Two .ini files will be searched by the launcher - ``py.ini`` in the current
+user's "application data" directory (i.e. the directory returned by calling the
+Windows function SHGetFolderPath with CSIDL_LOCAL_APPDATA) and ``py.ini`` in the
+same directory as the launcher. The same .ini files are used for both the
+'console' version of the launcher (i.e. py.exe) and for the 'windows' version
+(i.e. pyw.exe)
 
-    Customization specified in the "application directory" will have
-    precedence over the one next to the executable, so a user, who may not
-    have write access to the .ini file next to the launcher, can override
-    commands in that global .ini file)
+Customization specified in the "application directory" will have precedence over
+the one next to the executable, so a user, who may not have write access to the
+.ini file next to the launcher, can override commands in that global .ini file)
 
 Customizing default Python versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -488,6 +622,78 @@ particular version was chosen and the exact command-line used to execute the
 target Python.
 
 
+
+Finding modules
+===============
+
+Python usually stores its library (and thereby your site-packages folder) in the
+installation directory.  So, if you had installed Python to
+:file:`C:\\Python\\`, the default library would reside in
+:file:`C:\\Python\\Lib\\` and third-party modules should be stored in
+:file:`C:\\Python\\Lib\\site-packages\\`.
+
+This is how :data:`sys.path` is populated on Windows:
+
+* An empty entry is added at the start, which corresponds to the current
+  directory.
+
+* If the environment variable :envvar:`PYTHONPATH` exists, as described in
+  :ref:`using-on-envvars`, its entries are added next.  Note that on Windows,
+  paths in this variable must be separated by semicolons, to distinguish them
+  from the colon used in drive identifiers (``C:\`` etc.).
+
+* Additional "application paths" can be added in the registry as subkeys of
+  :samp:`\\SOFTWARE\\Python\\PythonCore\\{version}\\PythonPath` under both the
+  ``HKEY_CURRENT_USER`` and ``HKEY_LOCAL_MACHINE`` hives.  Subkeys which have
+  semicolon-delimited path strings as their default value will cause each path
+  to be added to :data:`sys.path`.  (Note that all known installers only use
+  HKLM, so HKCU is typically empty.)
+
+* If the environment variable :envvar:`PYTHONHOME` is set, it is assumed as
+  "Python Home".  Otherwise, the path of the main Python executable is used to
+  locate a "landmark file" (``Lib\os.py``) to deduce the "Python Home".  If a
+  Python home is found, the relevant sub-directories added to :data:`sys.path`
+  (``Lib``, ``plat-win``, etc) are based on that folder.  Otherwise, the core
+  Python path is constructed from the PythonPath stored in the registry.
+
+* If the Python Home cannot be located, no :envvar:`PYTHONPATH` is specified in
+  the environment, and no registry entries can be found, a default path with
+  relative entries is used (e.g. ``.\Lib;.\plat-win``, etc).
+
+The end result of all this is:
+
+* When running :file:`python.exe`, or any other .exe in the main Python
+  directory (either an installed version, or directly from the PCbuild
+  directory), the core path is deduced, and the core paths in the registry are
+  ignored.  Other "application paths" in the registry are always read.
+
+* When Python is hosted in another .exe (different directory, embedded via COM,
+  etc), the "Python Home" will not be deduced, so the core path from the
+  registry is used.  Other "application paths" in the registry are always read.
+
+* If Python can't find its home and there is no registry (eg, frozen .exe, some
+  very strange installation setup) you get a path with some default, but
+  relative, paths.
+
+For those who want to bundle Python into their application or distribution, the
+following advice will prevent conflicts with other installations:
+
+* If you are loading :file:`python3.dll` or :file:`python35.dll` in your own
+  executable, explicitly call :c:func:`Py_SetPath` or (at least)
+  :c:func:`Py_SetProgramName` before :c:func:`Py_Initialize`.
+
+* Clear and/or overwrite :envvar:`PYTHONPATH` and set :envvar:`PYTHONHOME`
+  before launching :file:`python.exe` from your application.
+
+* If you cannot use the previous suggestions (for example, you are a
+  distribution that allows people to run :file:`python.exe` directly), ensure
+  that the landmark file (:file:`Lib\\os.py`) exists in your bundled library.
+  (Note that it will not be detected inside a ZIP file.)
+
+These will ensure that the files in a system-wide installation will not take
+precedence over the copy of the standard library bundled with your application.
+Otherwise, your users may experience problems using your application.
+
 Additional modules
 ==================
 
@@ -498,7 +704,6 @@ and external, and snippets exist to use these features.
 The Windows-specific standard modules are documented in
 :ref:`mswin-specific-services`.
 
-
 PyWin32
 -------
 
@@ -557,20 +762,8 @@ latest release's source or just grab a fresh `checkout
 <https://docs.python.org/devguide/setup.html#getting-the-source-code>`_.
 
 The source tree contains a build solution and project files for Microsoft
-Visual C++, which is the compiler used to build the official Python releases.
-View the :file:`readme.txt` in their respective directories:
-
-+--------------------+--------------+-----------------------+
-| Directory          | MSVC version | Visual Studio version |
-+====================+==============+=======================+
-| :file:`PC/VS9.0/`  | 9.0          | 2008                  |
-+--------------------+--------------+-----------------------+
-| :file:`PCbuild/`   | 10.0         | 2010                  |
-+--------------------+--------------+-----------------------+
-
-Note that any build directories within the :file:`PC` directory are not
-necessarily fully supported.  The :file:`PCbuild` directory contains the files
-for the compiler used to build the official release.
+Visual Studio 2015, which is the compiler used to build the official Python
+releases. These files are in the :file:`PCbuild` directory.
 
 Check :file:`PCbuild/readme.txt` for general information on the build process.
 
@@ -603,5 +796,3 @@ Other resources
 
    :pep:`397` - Python launcher for Windows
       The proposal for the launcher to be included in the Python distribution.
-
-
diff --git a/Doc/whatsnew/2.1.rst b/Doc/whatsnew/2.1.rst
index 5058bf1..ff15662 100644
--- a/Doc/whatsnew/2.1.rst
+++ b/Doc/whatsnew/2.1.rst
@@ -219,7 +219,7 @@ comparison.  I won't cover the C API here, but will refer you to PEP 207, or to
 
 .. seealso::
 
-   :pep:`207` - Rich Comparisions
+   :pep:`207` - Rich Comparisons
       Written by Guido van Rossum, heavily based on earlier work by David Ascher, and
       implemented by Guido van Rossum.
 
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst
index 1fdb365..1d4ce72 100644
--- a/Doc/whatsnew/3.3.rst
+++ b/Doc/whatsnew/3.3.rst
@@ -1579,7 +1579,7 @@ os
   avoid race conditions in multi-threaded programs.
 
 * The :mod:`os` module has a new :func:`~os.sendfile` function which provides
-  an efficent "zero-copy" way for copying data from one file (or socket)
+  an efficient "zero-copy" way for copying data from one file (or socket)
   descriptor to another. The phrase "zero-copy" refers to the fact that all of
   the copying of data between the two descriptors is done entirely by the
   kernel, with no copying of data into userspace buffers. :func:`~os.sendfile`
@@ -1908,7 +1908,7 @@ socketserver
 :meth:`~socketserver.BaseServer.service_actions` that is called by the
 :meth:`~socketserver.BaseServer.serve_forever` method in the service loop.
 :class:`~socketserver.ForkingMixIn` now uses this to clean up zombie
-child proceses.  (Contributed by Justin Warkentin in :issue:`11109`.)
+child processes.  (Contributed by Justin Warkentin in :issue:`11109`.)
 
 
 sqlite3
@@ -2360,7 +2360,7 @@ Porting Python code
   bytecode file, make sure to call :func:`importlib.invalidate_caches` to clear
   out the cache for the finders to notice the new file.
 
-* :exc:`ImportError` now uses the full name of the module that was attemped to
+* :exc:`ImportError` now uses the full name of the module that was attempted to
   be imported. Doctests that check ImportErrors' message will need to be
   updated to use the full name of the module instead of just the tail of the
   name.
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
new file mode 100644
index 0000000..f364317
--- /dev/null
+++ b/Doc/whatsnew/3.5.rst
@@ -0,0 +1,854 @@
+****************************
+  What's New In Python 3.5
+****************************
+
+:Release: |release|
+:Date: |today|
+
+.. 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:
+
+   XXX Describe the transmogrify() function added to the socket
+   module.
+   (Contributed by P.Y. Developer in :issue:`12345`.)
+
+   This saves the maintainer the effort of going through the Mercurial log
+   when researching a change.
+
+This article explains the new features in Python 3.5, compared to 3.4.
+
+For full details, see the :source:`Misc/NEWS` file.
+
+.. note::
+
+   Prerelease users should be aware that this document is currently in draft
+   form. It will be updated substantially as Python 3.5 moves towards release,
+   so it's worth checking back even after reading earlier versions.
+
+
+.. seealso::
+
+    :pep:`478` - Python 3.5 Release Schedule
+
+
+Summary -- Release highlights
+=============================
+
+.. This section singles out the most important changes in Python 3.5.
+   Brevity is key.
+
+New syntax features:
+
+*  :pep:`465`, a new matrix multiplication operator: ``a @ b``.
+
+New library modules:
+
+* :mod:`zipapp`: :ref:`Improving Python ZIP Application Support
+  <whatsnew-zipapp>` (:pep:`441`).
+
+New built-in features:
+
+* ``bytes % args``, ``bytearray % args``: :pep:`461` - Adding ``%`` formatting
+  to bytes and bytearray
+
+Implementation improvements:
+
+* When the ``LC_TYPE`` locale is the POSIX locale (``C`` locale),
+  :py:data:`sys.stdin` and :py:data:`sys.stdout` are now using the
+  ``surrogateescape`` error handler, instead of the ``strict`` error handler
+  (:issue:`19977`).
+
+* :pep:`488`, the elimination of ``.pyo`` files.
+
+Significantly Improved Library Modules:
+
+* None yet.
+
+Security improvements:
+
+* None yet.
+
+Please read on for a comprehensive list of user-facing changes.
+
+
+.. PEP-sized items next.
+
+.. _pep-4XX:
+
+.. PEP 4XX: Virtual Environments
+.. =============================
+
+
+.. (Implemented by Foo Bar.)
+
+.. .. seealso::
+
+    :pep:`4XX` - Python Virtual Environments
+       PEP written by Carl Meyer
+
+
+PEP 461 - Adding % formatting to bytes and bytearray
+----------------------------------------------------
+
+This PEP proposes adding % formatting operations similar to Python 2's ``str``
+type to :class:`bytes` and :class:`bytearray`.
+
+Examples::
+
+    >>> b'Hello %s!' % b'World'
+    b'Hello World!'
+    >>> b'x=%i y=%f' % (1, 2.5)
+    b'x=1 y=2.500000'
+
+Unicode is not allowed for ``%s``, but it is accepted by ``%a`` (equivalent of
+``repr(obj).encode('ascii', 'backslashreplace')``)::
+
+    >>> b'Hello %s!' % 'World'
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+    TypeError: %b requires bytes, or an object that implements __bytes__, not 'str'
+    >>> b'price: %a' % '10€'
+    b"price: '10\\u20ac'"
+
+.. seealso::
+
+   :pep:`461` -- Adding % formatting to bytes and bytearray
+
+
+PEP 465 - A dedicated infix operator for matrix multiplication
+--------------------------------------------------------------
+
+This PEP proposes a new binary operator to be used for matrix multiplication,
+called ``@``. (Mnemonic: ``@`` is ``*`` for mATrices.)
+
+.. seealso::
+
+   :pep:`465` -- A dedicated infix operator for matrix multiplication
+
+
+PEP 471 - os.scandir() function -- a better and faster directory iterator
+-------------------------------------------------------------------------
+
+:pep:`471` adds a new directory iteration function, :func:`os.scandir`,
+to the standard library. Additionally, :func:`os.walk` is now
+implemented using :func:`os.scandir`, which speeds it up by 3-5 times
+on POSIX systems and by 7-20 times on Windows systems.
+
+PEP and implementation written by Ben Hoyt with the help of Victor Stinner.
+
+.. seealso::
+
+   :pep:`471` -- os.scandir() function -- a better and faster directory
+   iterator
+
+
+PEP 475: Retry system calls failing with EINTR
+----------------------------------------------
+
+:pep:`475` adds support for automatic retry of system calls failing with
+:py:data:`~errno.EINTR`: this means that user code doesn't have to deal with
+EINTR or :exc:`InterruptedError` manually, and should make it more robust
+against asynchronous signal reception.
+
+.. seealso::
+
+   :pep:`475` -- Retry system calls failing with EINTR
+
+
+PEP 486: Make the Python Launcher aware of virtual environments
+---------------------------------------------------------------
+
+:pep:`486` makes the Windows launcher (see :pep:`397`) aware of an active
+virtual environment. When the default interpreter would be used and the
+``VIRTUAL_ENV`` environment variable is set, the interpreter in the virtual
+environment will be used.
+
+.. seealso::
+
+    :pep:`486` -- Make the Python Launcher aware of virtual environments
+
+
+PEP 488: Elimination of PYO files
+---------------------------------
+
+:pep:`488` does away with the concept of ``.pyo`` files. This means that
+``.pyc`` files represent both unoptimized and optimized bytecode. To prevent
+the need to constantly regenerate bytecode files, ``.pyc`` files now have an
+optional ``opt-`` tag in their name when the bytecode is optimized. This has
+the side-effect of no more bytecode file name clashes when running under either
+``-O`` or ``-OO``, thus allowing unoptimized, ``-O``, and ``-OO`` bytecode files
+to all exist simultaneously. :func:`importlib.util.cache_from_source` has an
+updated API to help with this change.
+
+.. seealso::
+
+   :pep:`488` -- Elimination of PYO files
+
+
+Other Language Changes
+======================
+
+Some smaller changes made to the core Python language are:
+
+* Added the ``'namereplace'`` error handlers.  The ``'backslashreplace'``
+  error handlers now works with decoding and translating.
+  (Contributed by Serhiy Storchaka in :issue:`19676` and :issue:`22286`.)
+
+* The :option:`-b` option now affects comparisons of :class:`bytes` with
+  :class:`int`.  (Contributed by Serhiy Storchaka in :issue:`23681`)
+
+
+New Modules
+===========
+
+.. _whatsnew-zipapp:
+
+zipapp
+------
+
+The new :mod:`zipapp` module (specified in :pep:`441`) provides an API and
+command line tool for creating executable Python Zip Applications, which
+were introduced in Python 2.6 in :issue:`1739468` but which were not well
+publicised, either at the time or since.
+
+With the new module, bundling your application is as simple as putting all
+the files, including a ``__main__.py`` file, into a directory ``myapp``
+and running::
+
+    $ python -m zipapp myapp
+    $ python myapp.pyz
+
+
+Improved Modules
+================
+
+argparse
+--------
+
+* :class:`~argparse.ArgumentParser` now allows to disable
+  :ref:`abbreviated usage <prefix-matching>` of long options by setting
+  :ref:`allow_abbrev` to ``False``.
+  (Contributed by Jonathan Paugh, Steven Bethard, paul j3 and Daniel Eriksson.)
+
+cgi
+---
+
+* :class:`~cgi.FieldStorage` now supports the context management protocol.
+  (Contributed by Berker Peksag in :issue:`20289`.)
+
+code
+----
+
+* The :func:`code.InteractiveInterpreter.showtraceback` method now prints
+  the full chained traceback, just like the interactive interpreter.
+  (Contributed by Claudiu Popa in :issue:`17442`.)
+
+compileall
+----------
+
+* :func:`compileall.compile_dir` and :mod:`compileall`'s command-line interface
+  can now do parallel bytecode compilation.
+  (Contributed by Claudiu Popa in :issue:`16104`.)
+
+contextlib
+----------
+
+* The new :func:`contextlib.redirect_stderr` context manager(similar to
+  :func:`contextlib.redirect_stdout`) makes it easier for utility scripts to
+  handle inflexible APIs that write their output to :data:`sys.stderr` and
+  don't provide any options to redirect it.
+  (Contributed by Berker Peksag in :issue:`22389`.)
+
+curses
+------
+* The new :func:`curses.update_lines_cols` function updates the variables
+  :envvar:`curses.LINES` and :envvar:`curses.COLS`.
+
+difflib
+-------
+
+* The charset of the HTML document generated by :meth:`difflib.HtmlDiff.make_file`
+  can now be customized by using *charset* keyword-only parameter.  The default
+  charset of HTML document changed from ``'ISO-8859-1'`` to ``'utf-8'``.
+  (Contributed by Berker Peksag in :issue:`2052`.)
+
+* It's now possible to compare lists of byte strings with
+  :func:`difflib.diff_bytes` (fixes a regression from Python 2).
+
+distutils
+---------
+
+* The ``build`` and ``build_ext`` commands now accept a ``-j``
+  option to enable parallel building of extension modules.
+  (Contributed by Antoine Pitrou in :issue:`5309`.)
+
+doctest
+-------
+
+* :func:`doctest.DocTestSuite` returns an empty :class:`unittest.TestSuite` if
+  *module* contains no docstrings instead of raising :exc:`ValueError`.
+  (Contributed by Glenn Jones in :issue:`15916`.)
+
+glob
+----
+
+* :func:`~glob.iglob` and :func:`~glob.glob` now support recursive search in
+  subdirectories using the "``**``" pattern.
+  (Contributed by Serhiy Storchaka in :issue:`13968`.)
+
+imaplib
+-------
+
+* :class:`IMAP4` now supports the context management protocol.  When used in a
+  :keyword:`with` statement, the IMAP4 ``LOGOUT`` command will be called
+  automatically at the end of the block.  (Contributed by Tarek Ziadé and
+  Serhiy Storchaka in :issue:`4972`.)
+
+imghdr
+------
+
+* :func:`~imghdr.what` now recognizes the `OpenEXR <http://www.openexr.com>`_
+  format.  (Contributed by Martin Vignali and Claudiu Popa in :issue:`20295`.)
+
+importlib
+---------
+
+* :class:`importlib.util.LazyLoader` allows for the lazy loading of modules in
+  applications where startup time is paramount.
+  (Contributed by Brett Cannon in :issue:`17621`.)
+
+* :func:`importlib.abc.InspectLoader.source_to_code` is now a
+  static method to make it easier to work with source code in a string.
+  With a module object that you want to initialize you can then use
+  ``exec(code, module.__dict__)`` to execute the code in the module.
+
+* :func:`importlib.util.module_from_spec` is now the preferred way to create a
+  new module. Compared to :class:`types.ModuleType`, this new function will set
+  the various import-controlled attributes based on the passed-in spec object.
+
+inspect
+-------
+
+* :class:`inspect.Signature` and :class:`inspect.Parameter` are now
+  picklable and hashable.  (Contributed by Yury Selivanov in :issue:`20726`
+  and :issue:`20334`.)
+
+* New class method :meth:`inspect.Signature.from_callable`, which makes
+  subclassing of :class:`~inspect.Signature` easier.  (Contributed
+  by Yury Selivanov and Eric Snow in :issue:`17373`.)
+
+ipaddress
+---------
+
+* :class:`ipaddress.IPv4Network` and :class:`ipaddress.IPv6Network` now
+  accept an ``(address, netmask)`` tuple argument, so as to easily construct
+  network objects from existing addresses.  (Contributed by Peter Moody
+  and Antoine Pitrou in :issue:`16531`.)
+
+json
+----
+
+* The output of :mod:`json.tool` command line interface is now in the same
+  order as the input. Use the :option:`--sort-keys` option to sort the output
+  of dictionaries alphabetically by key.  (Contributed by Berker Peksag in
+  :issue:`21650`.)
+
+* JSON decoder now raises :exc:`json.JSONDecodeError` instead of
+  :exc:`ValueError`.   (Contributed by Serhiy Storchaka in :issue:`19361`.)
+
+os
+--
+
+* New :func:`os.scandir` function that exposes file information from
+  the operating system when listing a directory. :func:`os.scandir`
+  returns an iterator of :class:`os.DirEntry` objects corresponding to
+  the entries in the directory given by *path*. (Contributed by Ben
+  Hoyt with the help of Victor Stinner in :issue:`22524`.)
+
+* :class:`os.stat_result` now has a :attr:`~os.stat_result.st_file_attributes`
+  attribute on Windows.  (Contributed by Ben Hoyt in :issue:`21719`.)
+
+os.path
+-------
+
+* New :func:`~os.path.commonpath` function that extracts common path prefix.
+  Unlike the :func:`~os.path.commonprefix` function, it always returns a valid
+  patch.  (Contributed by Rafik Draoui and Serhiy Storchaka in :issue:`10395`.)
+
+pickle
+------
+
+* Serializing more "lookupable" objects (such as unbound methods or nested
+  classes) now are supported with pickle protocols < 4.
+  (Contributed by Serhiy Storchaka in :issue:`23611`.)
+
+re
+--
+
+* Number of capturing groups in regular expression is no longer limited by 100.
+  (Contributed by Serhiy Storchaka in :issue:`22437`.)
+
+* Now unmatched groups are replaced with empty strings in :func:`re.sub`
+  and :func:`re.subn`.  (Contributed by Serhiy Storchaka in :issue:`1519638`.)
+
+math
+----
+
+* :data:`math.inf` and :data:`math.nan` constants added.  (Contributed by Mark
+  Dickinson in :issue:`23185`.)
+
+shutil
+------
+
+* :func:`~shutil.move` now accepts a *copy_function* argument, allowing,
+  for example, :func:`~shutil.copy` to be used instead of the default
+  :func:`~shutil.copy2` if there is a need to ignore metadata.  (Contributed by
+  Claudiu Popa in :issue:`19840`.)
+
+signal
+------
+
+* On Windows, :func:`signal.set_wakeup_fd` now also supports socket handles.
+  (Contributed by Victor Stinner in :issue:`22018`.)
+
+* Different constants of :mod:`signal` module are now enumeration values using
+  the :mod:`enum` module. This allows meaningful names to be printed during
+  debugging, instead of integer “magic numbers”.  (Contributed by Giampaolo
+  Rodola' in :issue:`21076`.)
+
+smtpd
+-----
+
+* Both :class:`~smtpd.SMTPServer` and :class:`smtpd.SMTPChannel` now accept a
+  *decode_data* keyword to determine if the DATA portion of the SMTP
+  transaction is decoded using the ``utf-8`` codec or is instead provided to
+  :meth:`~smtpd.SMTPServer.process_message` as a byte string.  The default
+  is ``True`` for backward compatibility reasons, but will change to ``False``
+  in Python 3.6.  (Contributed by Maciej Szulik in :issue:`19662`.)
+
+* It is now possible to provide, directly or via name resolution, IPv6
+  addresses in the :class:`~smtpd.SMTPServer` constructor, and have it
+  successfully connect.  (Contributed by Milan Oberkirch in :issue:`14758`.)
+
+* :mod:`~smtpd.SMTPServer` now supports :rfc:`6531` via the *enable_SMTPUTF8*
+  constructor argument and a user-provided
+  :meth:`~smtpd.SMTPServer.process_smtputf8_message` method.
+
+smtplib
+-------
+
+* A new :meth:`~smtplib.SMTP.auth` method provides a convenient way to
+  implement custom authentication mechanisms.
+  (Contributed by Milan Oberkirch in :issue:`15014`.)
+
+* Additional debuglevel (2) shows timestamps for debug messages in
+  :class:`smtplib.SMTP`.  (Contributed by Gavin Chappell and Maciej Szulik in
+  :issue:`16914`.)
+
+sndhdr
+------
+
+* :func:`~sndhdr.what` and :func:`~sndhdr.whathdr` now return
+  :func:`~collections.namedtuple`.
+  (Contributed by Claudiu Popa in :issue:`18615`.)
+
+socket
+------
+
+* New :meth:`socket.socket.sendfile` method allows to send a file over a socket
+  by using high-performance :func:`os.sendfile` function on UNIX resulting in
+  uploads being from 2x to 3x faster than when using plain
+  :meth:`socket.socket.send`.
+  (Contributed by Giampaolo Rodola' in :issue:`17552`.)
+
+subprocess
+----------
+
+* The new :func:`subprocess.run` function runs subprocesses and returns a
+  :class:`subprocess.CompletedProcess` object.  It Provides a more consistent
+  API than :func:`~subprocess.call`, :func:`~subprocess.check_call` and
+  :func:`~subprocess.check_output`.
+
+sysconfig
+---------
+
+* The user scripts directory on Windows is now versioned.
+  (Contributed by Paul Moore in :issue:`23437`.)
+
+tarfile
+-------
+
+* The :func:`tarfile.open` function now supports ``'x'`` (exclusive creation)
+  mode.  (Contributed by Berker Peksag in :issue:`21717`.)
+
+* The :meth:`~tarfile.TarFile.extractall` and :meth:`~tarfile.TarFile.extract`
+  methods now take a keyword parameter *numeric_only*. If set to ``True``,
+  the extracted files and directories will be owned by the numeric uid and gid
+  from the tarfile. If set to ``False`` (the default, and the behavior in
+  versions prior to 3.5), they will be owned bythe named user and group in the
+  tarfile.  (Contributed by Michael Vogt and Eric Smith in :issue:`23193`.)
+
+time
+----
+
+* The :func:`time.monotonic` function is now always available.  (Contributed by
+  Victor Stinner in :issue:`22043`.)
+
+urllib
+------
+
+* A new :class:`~urllib.request.HTTPPasswordMgrWithPriorAuth` allows HTTP Basic
+  Authentication credentials to be managed so as to eliminate unnecessary
+  ``401`` response handling, or to unconditionally send credentials
+  on the first request in order to communicate with servers that return a
+  ``404`` response instead of a ``401`` if the ``Authorization`` header is not
+  sent.  (Contributed by Matej Cepl in :issue:`19494` and Akshit Khurana in
+  :issue:`7159`.)
+
+wsgiref
+-------
+
+* *headers* parameter of :class:`wsgiref.headers.Headers` is now optional.
+  (Contributed by Pablo Torres Navarrete and SilentGhost in :issue:`5800`.)
+
+xmlrpc
+------
+
+* :class:`xmlrpc.client.ServerProxy` is now a :term:`context manager`.
+  (Contributed by Claudiu Popa in :issue:`20627`.)
+
+xml.sax
+-------
+
+* SAX parsers now support a character stream of
+  :class:`~xml.sax.xmlreader.InputSource` object.
+  (Contributed by Serhiy Storchaka in :issue:`2175`.)
+
+faulthandler
+------------
+
+* :func:`~faulthandler.enable`, :func:`~faulthandler.register`,
+  :func:`~faulthandler.dump_traceback` and
+  :func:`~faulthandler.dump_traceback_later` functions now accept file
+  descriptors.  (Contributed by Wei Wu in :issue:`23566`.)
+
+zipfile
+-------
+
+* Added support for writing ZIP files to unseekable streams.
+  (Contributed by Serhiy Storchaka in :issue:`23252`.)
+
+* The :func:`zipfile.ZipFile.open` function now supports ``'x'`` (exclusive
+  creation) mode.  (Contributed by Serhiy Storchaka in :issue:`21717`.)
+
+
+Optimizations
+=============
+
+The following performance enhancements have been added:
+
+* :func:`os.walk` has been sped up by 3-5x on POSIX systems and 7-20x
+  on Windows. This was done using the new :func:`os.scandir` function,
+  which exposes file information from the underlying ``readdir`` and
+  ``FindFirstFile``/``FindNextFile`` system calls. (Contributed by
+  Ben Hoyt with help from Victor Stinner in :issue:`23605`.)
+
+* Construction of ``bytes(int)`` (filled by zero bytes) is faster and uses less
+  memory for large objects. ``calloc()`` is used instead of ``malloc()`` to
+  allocate memory for these objects.
+
+* Some operations on :class:`~ipaddress.IPv4Network` and
+  :class:`~ipaddress.IPv6Network` have been massively sped up, such as
+  :meth:`~ipaddress.IPv4Network.subnets`, :meth:`~ipaddress.IPv4Network.supernet`,
+  :func:`~ipaddress.summarize_address_range`, :func:`~ipaddress.collapse_addresses`.
+  The speed up can range from 3x to 15x.
+  (:issue:`21486`, :issue:`21487`, :issue:`20826`)
+
+* Many operations on :class:`io.BytesIO` are now 50% to 100% faster.
+  (Contributed by Serhiy Storchaka in :issue:`15381` and David Wilson in
+  :issue:`22003`.)
+
+* :func:`marshal.dumps` is now faster (65%-85% with versions 3--4, 20-25% with
+  versions 0--2 on typical data, and up to 5x in best cases).
+  (Contributed by Serhiy Storchaka in :issue:`20416` and :issue:`23344`.)
+
+
+Build and C API Changes
+=======================
+
+Changes to Python's build process and to the C API include:
+
+* New ``calloc`` functions:
+
+  * :c:func:`PyMem_RawCalloc`
+  * :c:func:`PyMem_Calloc`
+  * :c:func:`PyObject_Calloc`
+  * :c:func:`_PyObject_GC_Calloc`
+
+
+Deprecated
+==========
+
+Unsupported Operating Systems
+-----------------------------
+
+* Windows XP - Per :PEP:`11`, Microsoft support of Windows XP has ended.
+
+
+Deprecated Python modules, functions and methods
+------------------------------------------------
+
+* The :mod:`formatter` module has now graduated to full deprecation and is still
+  slated for removal in Python 3.6.
+
+* :mod:`smtpd` has in the past always decoded the DATA portion of email
+  messages using the ``utf-8`` codec.  This can now be controlled by the new
+  *decode_data* keyword to :class:`~smtpd.SMTPServer`.  The default value is
+  ``True``, but this default is deprecated.  Specify the *decode_data* keyword
+  with an appropriate value to avoid the deprecation warning.
+
+* Directly assigning values to the :attr:`~http.cookies.Morsel.key`,
+  :attr:`~http.cookies.Morsel.value` and
+  :attr:`~http.cookies.Morsel.coded_value` of :class:`~http.cookies.Morsel`
+  objects is deprecated.  Use the :func:`~http.cookies.Morsel.set` method
+  instead.  In addition, the undocumented *LegalChars* parameter of
+  :func:`~http.cookies.Morsel.set` is deprecated, and is now ignored.
+
+* Passing a format string as keyword argument *format_string* to the
+  :meth:`~string.Formatter.format` method of the :class:`string.Formatter`
+  class has been deprecated.
+
+
+Deprecated functions and types of the C API
+-------------------------------------------
+
+* None yet.
+
+
+Deprecated features
+-------------------
+
+* None yet.
+
+
+Removed
+=======
+
+API and Feature Removals
+------------------------
+
+The following obsolete and previously deprecated APIs and features have been
+removed:
+
+* The ``__version__`` attribute has been dropped from the email package.  The
+  email code hasn't been shipped separately from the stdlib for a long time,
+  and the ``__version__`` string was not updated in the last few releases.
+
+* The internal ``Netrc`` class in the :mod:`ftplib` module was deprecated in
+  3.4, and has now been removed.
+  (Contributed by Matt Chaput in :issue:`6623`.)
+
+* The concept of ``.pyo`` files has been removed.
+
+* The JoinableQueue class in the provisional asyncio module was deprecated
+  in 3.4.4 and is now removed (:issue:`23464`).
+
+
+Porting to Python 3.5
+=====================
+
+This section lists previously described changes and other bugfixes
+that may require changes to your code.
+
+Changes in the Python API
+-------------------------
+
+* :pep:`475`: Examples of functions which are now retried when interrupted
+  instead of raising :exc:`InterruptedError` if the signal handler does not
+  raise an exception:
+
+  - :func:`open`, :func:`os.open`, :func:`io.open`
+  - functions of the :mod:`faulthandler` module
+  - :mod:`os` functions:
+
+    * :func:`os.fchdir`
+    * :func:`os.fchmod`
+    * :func:`os.fchown`
+    * :func:`os.fdatasync`
+    * :func:`os.fstat`
+    * :func:`os.fstatvfs`
+    * :func:`os.fsync`
+    * :func:`os.ftruncate`
+    * :func:`os.mkfifo`
+    * :func:`os.mknod`
+    * :func:`os.posix_fadvise`
+    * :func:`os.posix_fallocate`
+    * :func:`os.pread`
+    * :func:`os.pwrite`
+    * :func:`os.read`
+    * :func:`os.readv`
+    * :func:`os.sendfile`
+    * :func:`os.wait3`
+    * :func:`os.wait4`
+    * :func:`os.wait`
+    * :func:`os.waitid`
+    * :func:`os.waitpid`
+    * :func:`os.write`
+    * :func:`os.writev`
+    * special cases: :func:`os.close` and :func:`os.dup2` now ignore
+      :py:data:`~errno.EINTR` error, the syscall is not retried (see the PEP
+      for the rationale)
+
+  - :func:`select.select`, :func:`select.poll.poll`, :func:`select.epoll.poll`,
+    :func:`select.kqueue.control`, :func:`select.devpoll.poll`
+  - :func:`socket.socket` methods:
+
+    * :meth:`~socket.socket.accept`
+    * :meth:`~socket.socket.connect` (except for non-blocking sockets)
+    * :meth:`~socket.socket.recv`
+    * :meth:`~socket.socket.recvfrom`
+    * :meth:`~socket.socket.recvmsg`
+    * :meth:`~socket.socket.send`
+    * :meth:`~socket.socket.sendall`
+    * :meth:`~socket.socket.sendmsg`
+    * :meth:`~socket.socket.sendto`
+
+  - :func:`signal.sigtimedwait`, :func:`signal.sigwaitinfo`
+  - :func:`time.sleep`
+
+* Before Python 3.5, a :class:`datetime.time` object was considered to be false
+  if it represented midnight in UTC.  This behavior was considered obscure and
+  error-prone and has been removed in Python 3.5.  See :issue:`13936` for full
+  details.
+
+* :meth:`ssl.SSLSocket.send()` now raises either :exc:`ssl.SSLWantReadError`
+  or :exc:`ssl.SSLWantWriteError` on a non-blocking socket if the operation
+  would block. Previously, it would return 0.  See :issue:`20951`.
+
+* The ``__name__`` attribute of generator is now set from the function name,
+  instead of being set from the code name. Use ``gen.gi_code.co_name`` to
+  retrieve the code name. Generators also have a new ``__qualname__``
+  attribute, the qualified name, which is now used for the representation
+  of a generator (``repr(gen)``). See :issue:`21205`.
+
+* The deprecated "strict" mode and argument of :class:`~html.parser.HTMLParser`,
+  :meth:`HTMLParser.error`, and the :exc:`HTMLParserError` exception have been
+  removed.  (Contributed by Ezio Melotti in :issue:`15114`.)
+  The *convert_charrefs* argument of :class:`~html.parser.HTMLParser` is
+  now ``True`` by default.  (Contributed by Berker Peksag in :issue:`21047`.)
+
+* Although it is not formally part of the API, it is worth noting for porting
+  purposes (ie: fixing tests) that error messages that were previously of the
+  form "'sometype' does not support the buffer protocol" are now of the form "a
+  bytes-like object is required, not 'sometype'".  (Contributed by Ezio Melotti
+  in :issue:`16518`.)
+
+* If the current directory is set to a directory that no longer exists then
+  :exc:`FileNotFoundError` will no longer be raised and instead
+  :meth:`~importlib.machinery.FileFinder.find_spec` will return ``None``
+  **without** caching ``None`` in :data:`sys.path_importer_cache` which is
+  different than the typical case (:issue:`22834`).
+
+* HTTP status code and messages from :mod:`http.client` and :mod:`http.server`
+  were refactored into a common :class:`~http.HTTPStatus` enum.  The values in
+  :mod:`http.client` and :mod:`http.server` remain available for backwards
+  compatibility.  (Contributed by Demian Brecht in :issue:`21793`.)
+
+* When an import loader defines :meth:`~importlib.machinery.Loader.exec_module`
+  it is now expected to also define
+  :meth:`~importlib.machinery.Loader.create_module` (raises a
+  :exc:`DeprecationWarning` now, will be an error in Python 3.6). If the loader
+  inherits from :class:`importlib.abc.Loader` then there is nothing to do, else
+  simply define :meth:`~importlib.machinery.Loader.create_module` to return
+  ``None`` (:issue:`23014`).
+
+* :func:`re.split` always ignored empty pattern matches, so the ``'x*'``
+  pattern worked the same as ``'x+'``, and the ``'\b'`` pattern never worked.
+  Now :func:`re.split` raises a warning if the pattern could match
+  an empty string.  For compatibility use patterns that never match an empty
+  string (e.g. ``'x+'`` instead of ``'x*'``).  Patterns that could only match
+  an empty string (such as ``'\b'``) now raise an error.
+
+* The :class:`~http.cookies.Morsel` dict-like interface has been made self
+  consistent:  morsel comparison now takes the :attr:`~http.cookies.Morsel.key`
+  and :attr:`~http.cookies.Morsel.value` into account,
+  :meth:`~http.cookies.Morsel.copy` now results in a
+  :class:`~http.cookies.Morsel` instance rather than a :class:`dict`, and
+  :meth:`~http.cookies.Morsel.update` will now raise an exception if any of the
+  keys in the update dictionary are invalid.  In addition, the undocumented
+  *LegalChars* parameter of :func:`~http.cookies.Morsel.set` is deprecated and
+  is now ignored.  (:issue:`2211`)
+
+* :pep:`488` has removed ``.pyo`` files from Python and introduced the optional
+  ``opt-`` tag in ``.pyc`` file names. The
+  :func:`importlib.util.cache_from_source` has gained an *optimization*
+  parameter to help control the ``opt-`` tag. Because of this, the
+  *debug_override* parameter of the function is now deprecated. `.pyo` files
+  are also no longer supported as a file argument to the Python interpreter and
+  thus serve no purpose when distributed on their own (i.e. sourcless code
+  distribution). Due to the fact that the magic number for bytecode has changed
+  in Python 3.5, all old `.pyo` files from previous versions of Python are
+  invalid regardless of this PEP.
+
+ * The :mod:`socket` module now exports the CAN_RAW_FD_FRAMES constant on linux
+   3.6 and greater.
+
+* The `pygettext.py` Tool now uses the standard +NNNN format for timezones in
+  the POT-Creation-Date header.
+
+* The :mod:`smtplib` module now uses :data:`sys.stderr` instead of previous
+  module level :data:`stderr` variable for debug output.  If your (test)
+  program depends on patching the module level variable to capture the debug
+  output, you will need to update it to capture sys.stderr instead.
+
+
+Changes in the C API
+--------------------
+
+* The undocumented :c:member:`~PyMemoryViewObject.format` member of the
+  (non-public) :c:type:`PyMemoryViewObject` structure has been removed.
+
+  All extensions relying on the relevant parts in ``memoryobject.h``
+  must be rebuilt.
+
+* The :c:type:`PyMemAllocator` structure was renamed to
+  :c:type:`PyMemAllocatorEx` and a new ``calloc`` field was added.
+
+* Removed non-documented macro :c:macro:`PyObject_REPR` which leaked references.
+  Use format character ``%R`` in :c:func:`PyUnicode_FromFormat`-like functions
+  to format the :func:`repr` of the object.
+
+* Because the lack of the :attr:`__module__` attribute breaks pickling and
+  introspection, a deprecation warning now is raised for builtin type without
+  the :attr:`__module__` attribute.  Would be an AttributeError in future.
+  (:issue:`20204`)
diff --git a/Doc/whatsnew/index.rst b/Doc/whatsnew/index.rst
index 29902e4..edb5502 100644
--- a/Doc/whatsnew/index.rst
+++ b/Doc/whatsnew/index.rst
@@ -11,6 +11,7 @@ anyone wishing to stay up-to-date after a new release.
 .. toctree::
    :maxdepth: 2
 
+   3.5.rst
    3.4.rst
    3.3.rst
    3.2.rst
diff --git a/Grammar/Grammar b/Grammar/Grammar
index d7aaffd..94898d3 100644
--- a/Grammar/Grammar
+++ b/Grammar/Grammar
@@ -40,7 +40,7 @@ small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
 expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
                      ('=' (yield_expr|testlist_star_expr))*)
 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
-augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
             '<<=' | '>>=' | '**=' | '//=')
 # For normal assignments, additional restrictions enforced by the interpreter
 del_stmt: 'del' exprlist
@@ -89,7 +89,7 @@ and_test: not_test ('and' not_test)*
 not_test: 'not' not_test | comparison
 comparison: expr (comp_op expr)*
 # <> isn't actually a valid comparison operator in Python. It's here for the
-# sake of a __future__ import described in PEP 401
+# sake of a __future__ import described in PEP 401 (which really works :-)
 comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
 star_expr: '*' expr
 expr: xor_expr ('|' xor_expr)*
@@ -97,7 +97,7 @@ xor_expr: and_expr ('^' and_expr)*
 and_expr: shift_expr ('&' shift_expr)*
 shift_expr: arith_expr (('<<'|'>>') arith_expr)*
 arith_expr: term (('+'|'-') term)*
-term: factor (('*'|'/'|'%'|'//') factor)*
+term: factor (('*'|'@'|'/'|'%'|'//') factor)*
 factor: ('+'|'-'|'~') factor | power
 power: atom trailer* ['**' factor]
 atom: ('(' [yield_expr|testlist_comp] ')' |
@@ -117,7 +117,7 @@ dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
 classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
 
 arglist: (argument ',')* (argument [',']
-                         |'*' test (',' argument)* [',' '**' test] 
+                         |'*' test (',' argument)* [',' '**' test]
                          |'**' test)
 # The reason that keywords are test nodes instead of NAME is that using NAME
 # results in an ambiguity. ast.c makes sure it's a NAME.
diff --git a/Include/Python-ast.h b/Include/Python-ast.h
index 67d677b..37e9a60 100644
--- a/Include/Python-ast.h
+++ b/Include/Python-ast.h
@@ -15,9 +15,9 @@ typedef struct _slice *slice_ty;
 
 typedef enum _boolop { And=1, Or=2 } boolop_ty;
 
-typedef enum _operator { Add=1, Sub=2, Mult=3, Div=4, Mod=5, Pow=6, LShift=7,
-                         RShift=8, BitOr=9, BitXor=10, BitAnd=11, FloorDiv=12 }
-                         operator_ty;
+typedef enum _operator { Add=1, Sub=2, Mult=3, MatMult=4, Div=5, Mod=6, Pow=7,
+                         LShift=8, RShift=9, BitOr=10, BitXor=11, BitAnd=12,
+                         FloorDiv=13 } operator_ty;
 
 typedef enum _unaryop { Invert=1, Not=2, UAdd=3, USub=4 } unaryop_ty;
 
diff --git a/Include/Python.h b/Include/Python.h
index 2dd8290..46d2ece 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -112,6 +112,7 @@
 #include "pyarena.h"
 #include "modsupport.h"
 #include "pythonrun.h"
+#include "pylifecycle.h"
 #include "ceval.h"
 #include "sysmodule.h"
 #include "intrcheck.h"
diff --git a/Include/abstract.h b/Include/abstract.h
index 6e850b8..83dbf94 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -266,6 +266,12 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
      PyAPI_FUNC(PyObject *) PyObject_Call(PyObject *callable_object,
                                           PyObject *args, PyObject *kw);
 
+#ifndef Py_LIMITED_API
+     PyAPI_FUNC(PyObject *) _Py_CheckFunctionResult(PyObject *func,
+                                                    PyObject *result,
+                                                    const char *where);
+#endif
+
        /*
      Call a callable Python object, callable_object, with
      arguments and keywords arguments.  The 'args' argument can not be
@@ -658,6 +664,12 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
      o1*o2.
        */
 
+     PyAPI_FUNC(PyObject *) PyNumber_MatrixMultiply(PyObject *o1, PyObject *o2);
+
+       /*
+     This is the equivalent of the Python expression: o1 @ o2.
+       */
+
      PyAPI_FUNC(PyObject *) PyNumber_FloorDivide(PyObject *o1, PyObject *o2);
 
        /*
@@ -832,6 +844,12 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
      o1 *= o2.
        */
 
+     PyAPI_FUNC(PyObject *) PyNumber_InPlaceMatrixMultiply(PyObject *o1, PyObject *o2);
+
+       /*
+     This is the equivalent of the Python expression: o1 @= o2.
+       */
+
      PyAPI_FUNC(PyObject *) PyNumber_InPlaceFloorDivide(PyObject *o1,
                                                         PyObject *o2);
 
diff --git a/Include/bytes_methods.h b/Include/bytes_methods.h
index 1498b8f..11d5f42 100644
--- a/Include/bytes_methods.h
+++ b/Include/bytes_methods.h
@@ -21,8 +21,8 @@ extern void _Py_bytes_title(char *result, char *s, Py_ssize_t len);
 extern void _Py_bytes_capitalize(char *result, char *s, Py_ssize_t len);
 extern void _Py_bytes_swapcase(char *result, char *s, Py_ssize_t len);
 
-/* This one gets the raw argument list. */
-extern PyObject* _Py_bytes_maketrans(PyObject *args);
+/* The maketrans() static method. */
+extern PyObject* _Py_bytes_maketrans(Py_buffer *frm, Py_buffer *to);
 
 /* Shared __doc__ strings. */
 extern const char _Py_isspace__doc__[];
diff --git a/Include/bytesobject.h b/Include/bytesobject.h
index 0ee8d36..e379bac 100644
--- a/Include/bytesobject.h
+++ b/Include/bytesobject.h
@@ -62,6 +62,7 @@ PyAPI_FUNC(void) PyBytes_Concat(PyObject **, PyObject *);
 PyAPI_FUNC(void) PyBytes_ConcatAndDel(PyObject **, PyObject *);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyBytes_Resize(PyObject **, Py_ssize_t);
+PyAPI_FUNC(PyObject *) _PyBytes_Format(PyObject *, PyObject *);
 #endif
 PyAPI_FUNC(PyObject *) PyBytes_DecodeEscape(const char *, Py_ssize_t,
 						   const char *, Py_ssize_t,
diff --git a/Include/code.h b/Include/code.h
index 7c7e5bf..ff2b97e 100644
--- a/Include/code.h
+++ b/Include/code.h
@@ -21,7 +21,12 @@ typedef struct {
     PyObject *co_varnames;	/* tuple of strings (local variable names) */
     PyObject *co_freevars;	/* tuple of strings (free variable names) */
     PyObject *co_cellvars;      /* tuple of strings (cell variable names) */
-    /* The rest doesn't count for hash or comparisons */
+    /* The rest aren't used in either hash or comparisons, except for
+       co_name (used in both) and co_firstlineno (used only in
+       comparisons).  This is done to preserve the name and line number
+       for tracebacks and debuggers; otherwise, constant de-duplication
+       would collapse identical functions/lambdas defined on different lines.
+    */
     unsigned char *co_cell2arg; /* Maps cell vars which are arguments. */
     PyObject *co_filename;	/* unicode (where it was loaded from) */
     PyObject *co_name;		/* unicode (name, for reference) */
diff --git a/Include/codecs.h b/Include/codecs.h
index b3088e4..9e4f305 100644
--- a/Include/codecs.h
+++ b/Include/codecs.h
@@ -71,7 +71,7 @@ PyAPI_FUNC(int) PyCodec_KnownEncoding(
    object is passed through the encoder function found for the given
    encoding using the error handling method defined by errors. errors
    may be NULL to use the default method defined for the codec.
-   
+
    Raises a LookupError in case no encoder can be found.
 
  */
@@ -87,7 +87,7 @@ PyAPI_FUNC(PyObject *) PyCodec_Encode(
    object is passed through the decoder function found for the given
    encoding using the error handling method defined by errors. errors
    may be NULL to use the default method defined for the codec.
-   
+
    Raises a LookupError in case no encoder can be found.
 
  */
@@ -145,7 +145,7 @@ PyAPI_FUNC(PyObject *) _PyCodecInfo_GetIncrementalEncoder(
 
 
 
-/* --- Codec Lookup APIs -------------------------------------------------- 
+/* --- Codec Lookup APIs --------------------------------------------------
 
    All APIs return a codec object with incremented refcount and are
    based on _PyCodec_Lookup().  The same comments w/r to the encoding
@@ -225,6 +225,9 @@ PyAPI_FUNC(PyObject *) PyCodec_XMLCharRefReplaceErrors(PyObject *exc);
 /* replace the unicode encode error with backslash escapes (\x, \u and \U) */
 PyAPI_FUNC(PyObject *) PyCodec_BackslashReplaceErrors(PyObject *exc);
 
+/* replace the unicode encode error with backslash escapes (\N, \x, \u and \U) */
+PyAPI_FUNC(PyObject *) PyCodec_NameReplaceErrors(PyObject *exc);
+
 PyAPI_DATA(const char *) Py_hexdigits;
 
 #ifdef __cplusplus
diff --git a/Include/complexobject.h b/Include/complexobject.h
index 1934f3b..cb8c52c 100644
--- a/Include/complexobject.h
+++ b/Include/complexobject.h
@@ -14,21 +14,13 @@ typedef struct {
 
 /* Operations on complex numbers from complexmodule.c */
 
-#define c_sum _Py_c_sum
-#define c_diff _Py_c_diff
-#define c_neg _Py_c_neg
-#define c_prod _Py_c_prod
-#define c_quot _Py_c_quot
-#define c_pow _Py_c_pow
-#define c_abs _Py_c_abs
-
-PyAPI_FUNC(Py_complex) c_sum(Py_complex, Py_complex);
-PyAPI_FUNC(Py_complex) c_diff(Py_complex, Py_complex);
-PyAPI_FUNC(Py_complex) c_neg(Py_complex);
-PyAPI_FUNC(Py_complex) c_prod(Py_complex, Py_complex);
-PyAPI_FUNC(Py_complex) c_quot(Py_complex, Py_complex);
-PyAPI_FUNC(Py_complex) c_pow(Py_complex, Py_complex);
-PyAPI_FUNC(double) c_abs(Py_complex);
+PyAPI_FUNC(Py_complex) _Py_c_sum(Py_complex, Py_complex);
+PyAPI_FUNC(Py_complex) _Py_c_diff(Py_complex, Py_complex);
+PyAPI_FUNC(Py_complex) _Py_c_neg(Py_complex);
+PyAPI_FUNC(Py_complex) _Py_c_prod(Py_complex, Py_complex);
+PyAPI_FUNC(Py_complex) _Py_c_quot(Py_complex, Py_complex);
+PyAPI_FUNC(Py_complex) _Py_c_pow(Py_complex, Py_complex);
+PyAPI_FUNC(double) _Py_c_abs(Py_complex);
 #endif
 
 /* Complex object interface */
diff --git a/Include/dictobject.h b/Include/dictobject.h
index ef122bd..09dff59 100644
--- a/Include/dictobject.h
+++ b/Include/dictobject.h
@@ -50,6 +50,10 @@ PyAPI_DATA(PyTypeObject) PyDictValues_Type;
 
 PyAPI_FUNC(PyObject *) PyDict_New(void);
 PyAPI_FUNC(PyObject *) PyDict_GetItem(PyObject *mp, PyObject *key);
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(PyObject *) _PyDict_GetItem_KnownHash(PyObject *mp, PyObject *key,
+                                       Py_hash_t hash);
+#endif
 PyAPI_FUNC(PyObject *) PyDict_GetItemWithError(PyObject *mp, PyObject *key);
 PyAPI_FUNC(PyObject *) _PyDict_GetItemIdWithError(PyObject *dp,
                                                   struct _Py_Identifier *key);
@@ -58,6 +62,10 @@ PyAPI_FUNC(PyObject *) PyDict_SetDefault(
     PyObject *mp, PyObject *key, PyObject *defaultobj);
 #endif
 PyAPI_FUNC(int) PyDict_SetItem(PyObject *mp, PyObject *key, PyObject *item);
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(int) _PyDict_SetItem_KnownHash(PyObject *mp, PyObject *key,
+                                          PyObject *item, Py_hash_t hash);
+#endif
 PyAPI_FUNC(int) PyDict_DelItem(PyObject *mp, PyObject *key);
 PyAPI_FUNC(void) PyDict_Clear(PyObject *mp);
 PyAPI_FUNC(int) PyDict_Next(
diff --git a/Include/fileobject.h b/Include/fileobject.h
index 0939744..03155d3 100644
--- a/Include/fileobject.h
+++ b/Include/fileobject.h
@@ -32,17 +32,6 @@ PyAPI_DATA(int) Py_HasFileSystemDefaultEncoding;
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) PyFile_NewStdPrinter(int);
 PyAPI_DATA(PyTypeObject) PyStdPrinter_Type;
-
-#if defined _MSC_VER && _MSC_VER >= 1400
-/* A routine to check if a file descriptor is valid on Windows.  Returns 0
- * and sets errno to EBADF if it isn't.  This is to avoid Assertions
- * from various functions in the Windows CRT beginning with
- * Visual Studio 2005
- */
-int _PyVerify_fd(int fd);
-#else
-#define _PyVerify_fd(A) (1) /* dummy */
-#endif
 #endif /* Py_LIMITED_API */
 
 /* A routine to check if a file descriptor can be select()-ed. */
diff --git a/Include/fileutils.h b/Include/fileutils.h
index e9bad80..b4a683c 100644
--- a/Include/fileutils.h
+++ b/Include/fileutils.h
@@ -7,30 +7,59 @@ extern "C" {
 
 PyAPI_FUNC(PyObject *) _Py_device_encoding(int);
 
-PyAPI_FUNC(wchar_t *) _Py_char2wchar(
+PyAPI_FUNC(wchar_t *) Py_DecodeLocale(
     const char *arg,
     size_t *size);
 
-PyAPI_FUNC(char*) _Py_wchar2char(
+PyAPI_FUNC(char*) Py_EncodeLocale(
     const wchar_t *text,
     size_t *error_pos);
 
-#if defined(HAVE_STAT) && !defined(MS_WINDOWS)
-PyAPI_FUNC(int) _Py_wstat(
-    const wchar_t* path,
-    struct stat *buf);
+#ifndef Py_LIMITED_API
+
+#ifdef MS_WINDOWS
+struct _Py_stat_struct {
+    unsigned long st_dev;
+    __int64 st_ino;
+    unsigned short st_mode;
+    int st_nlink;
+    int st_uid;
+    int st_gid;
+    unsigned long st_rdev;
+    __int64 st_size;
+    time_t st_atime;
+    int st_atime_nsec;
+    time_t st_mtime;
+    int st_mtime_nsec;
+    time_t st_ctime;
+    int st_ctime_nsec;
+    unsigned long st_file_attributes;
+};
+#else
+#  define _Py_stat_struct stat
 #endif
 
-#ifdef HAVE_STAT
+PyAPI_FUNC(int) _Py_fstat(
+    int fd,
+    struct _Py_stat_struct *status);
+
+PyAPI_FUNC(int) _Py_fstat_noraise(
+    int fd,
+    struct _Py_stat_struct *status);
+#endif   /* Py_LIMITED_API */
+
 PyAPI_FUNC(int) _Py_stat(
     PyObject *path,
-    struct stat *statbuf);
-#endif
+    struct stat *status);
 
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _Py_open(
     const char *pathname,
     int flags);
+
+PyAPI_FUNC(int) _Py_open_noraise(
+    const char *pathname,
+    int flags);
 #endif
 
 PyAPI_FUNC(FILE *) _Py_wfopen(
@@ -45,6 +74,21 @@ PyAPI_FUNC(FILE*) _Py_fopen_obj(
     PyObject *path,
     const char *mode);
 
+PyAPI_FUNC(Py_ssize_t) _Py_read(
+    int fd,
+    void *buf,
+    size_t count);
+
+PyAPI_FUNC(Py_ssize_t) _Py_write(
+    int fd,
+    const void *buf,
+    size_t count);
+
+PyAPI_FUNC(Py_ssize_t) _Py_write_noraise(
+    int fd,
+    const void *buf,
+    size_t count);
+
 #ifdef HAVE_READLINK
 PyAPI_FUNC(int) _Py_wreadlink(
     const wchar_t *path,
@@ -70,8 +114,27 @@ PyAPI_FUNC(int) _Py_set_inheritable(int fd, int inheritable,
                                     int *atomic_flag_works);
 
 PyAPI_FUNC(int) _Py_dup(int fd);
+
+#ifndef MS_WINDOWS
+PyAPI_FUNC(int) _Py_get_blocking(int fd);
+
+PyAPI_FUNC(int) _Py_set_blocking(int fd, int blocking);
+#endif   /* !MS_WINDOWS */
+
+#if defined _MSC_VER && _MSC_VER >= 1400 && _MSC_VER < 1900
+/* A routine to check if a file descriptor is valid on Windows.  Returns 0
+ * and sets errno to EBADF if it isn't.  This is to avoid Assertions
+ * from various functions in the Windows CRT beginning with
+ * Visual Studio 2005
+ */
+int _PyVerify_fd(int fd);
+
+#else
+#define _PyVerify_fd(A) (1) /* dummy */
 #endif
 
+#endif   /* Py_LIMITED_API */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Include/genobject.h b/Include/genobject.h
index 65f1ecf..23571e6 100644
--- a/Include/genobject.h
+++ b/Include/genobject.h
@@ -25,6 +25,12 @@ typedef struct {
 
     /* List of weak reference. */
     PyObject *gi_weakreflist;
+
+    /* Name of the generator. */
+    PyObject *gi_name;
+
+    /* Qualified name of the generator. */
+    PyObject *gi_qualname;
 } PyGenObject;
 
 PyAPI_DATA(PyTypeObject) PyGen_Type;
@@ -33,6 +39,8 @@ PyAPI_DATA(PyTypeObject) PyGen_Type;
 #define PyGen_CheckExact(op) (Py_TYPE(op) == &PyGen_Type)
 
 PyAPI_FUNC(PyObject *) PyGen_New(struct _frame *);
+PyAPI_FUNC(PyObject *) PyGen_NewWithQualName(struct _frame *,
+    PyObject *name, PyObject *qualname);
 PyAPI_FUNC(int) PyGen_NeedsFinalizing(PyGenObject *);
 PyAPI_FUNC(int) _PyGen_FetchStopIterationValue(PyObject **);
 PyObject *_PyGen_Send(PyGenObject *, PyObject *);
diff --git a/Include/grammar.h b/Include/grammar.h
index ba7d19d..85120b9 100644
--- a/Include/grammar.h
+++ b/Include/grammar.h
@@ -37,7 +37,7 @@ typedef struct {
 typedef struct {
     int		 s_narcs;
     arc		*s_arc;		/* Array of arcs */
-	
+
     /* Optional accelerators */
     int		 s_lower;	/* Lowest label index */
     int		 s_upper;	/* Highest label index */
diff --git a/Include/memoryobject.h b/Include/memoryobject.h
index 382ca92..ab5ee09 100644
--- a/Include/memoryobject.h
+++ b/Include/memoryobject.h
@@ -45,9 +45,6 @@ typedef struct {
 } _PyManagedBufferObject;
 
 
-/* deprecated, removed in 3.5 */
-#define _Py_MEMORYVIEW_MAX_FORMAT 3 /* must be >= 3 */
-
 /* memoryview state flags */
 #define _Py_MEMORYVIEW_RELEASED    0x001  /* access to master buffer blocked */
 #define _Py_MEMORYVIEW_C           0x002  /* C-contiguous layout */
@@ -62,7 +59,6 @@ typedef struct {
     int flags;                    /* state flags */
     Py_ssize_t exports;           /* number of buffer re-exports */
     Py_buffer view;               /* private copy of the exporter's view */
-    char format[_Py_MEMORYVIEW_MAX_FORMAT]; /* deprecated, removed in 3.5 */
     PyObject *weakreflist;
     Py_ssize_t ob_array[1];       /* shape, strides, suboffsets */
 } PyMemoryViewObject;
diff --git a/Include/methodobject.h b/Include/methodobject.h
index 3cc2ea9..e2ad804 100644
--- a/Include/methodobject.h
+++ b/Include/methodobject.h
@@ -47,7 +47,7 @@ struct PyMethodDef {
 typedef struct PyMethodDef PyMethodDef;
 
 #define PyCFunction_New(ML, SELF) PyCFunction_NewEx((ML), (SELF), NULL)
-PyAPI_FUNC(PyObject *) PyCFunction_NewEx(PyMethodDef *, PyObject *, 
+PyAPI_FUNC(PyObject *) PyCFunction_NewEx(PyMethodDef *, PyObject *,
                                          PyObject *);
 
 /* Flag passed to newmethodobject */
@@ -66,7 +66,7 @@ PyAPI_FUNC(PyObject *) PyCFunction_NewEx(PyMethodDef *, PyObject *,
 
 /* METH_COEXIST allows a method to be entered even though a slot has
    already filled the entry.  When defined, the flag allows a separate
-   method, "__contains__" for example, to coexist with a defined 
+   method, "__contains__" for example, to coexist with a defined
    slot like sq_contains. */
 
 #define METH_COEXIST   0x0040
@@ -77,6 +77,7 @@ typedef struct {
     PyMethodDef *m_ml; /* Description of the C function to call */
     PyObject    *m_self; /* Passed as 'self' arg to the C func, can be NULL */
     PyObject    *m_module; /* The __module__ attribute, can be anything */
+    PyObject    *m_weakreflist; /* List of weak references */
 } PyCFunctionObject;
 #endif
 
diff --git a/Include/node.h b/Include/node.h
index 2e4e2ba..654ad85 100644
--- a/Include/node.h
+++ b/Include/node.h
@@ -26,7 +26,7 @@ PyAPI_FUNC(Py_ssize_t) _PyNode_SizeOf(node *n);
 
 /* Node access functions */
 #define NCH(n)		((n)->n_nchildren)
-	
+
 #define CHILD(n, i)	(&(n)->n_child[i])
 #define RCHILD(n, i)	(CHILD(n, NCH(n) + i))
 #define TYPE(n)		((n)->n_type)
diff --git a/Include/object.h b/Include/object.h
index 5f862ab..5716f66 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -65,6 +65,7 @@ whose size is determined when the object is allocated.
 #error Py_LIMITED_API is incompatible with Py_DEBUG, Py_TRACE_REFS, and Py_REF_DEBUG
 #endif
 
+
 #ifdef Py_TRACE_REFS
 /* Define pointers to support a doubly-linked list of all live heap objects. */
 #define _PyObject_HEAD_EXTRA            \
@@ -275,6 +276,9 @@ typedef struct {
     binaryfunc nb_inplace_true_divide;
 
     unaryfunc nb_index;
+
+    binaryfunc nb_matrix_multiply;
+    binaryfunc nb_inplace_matrix_multiply;
 } PyNumberMethods;
 
 typedef struct {
@@ -572,13 +576,6 @@ PyAPI_FUNC(PyObject *) PyObject_Dir(PyObject *);
 PyAPI_FUNC(int) Py_ReprEnter(PyObject *);
 PyAPI_FUNC(void) Py_ReprLeave(PyObject *);
 
-#ifndef Py_LIMITED_API
-/* Helper for passing objects to printf and the like.
-   Leaks refcounts.  Don't use it!
-*/
-#define PyObject_REPR(obj) PyUnicode_AsUTF8(PyObject_Repr(obj))
-#endif
-
 /* Flag bits for printing: */
 #define Py_PRINT_RAW    1       /* No string quotes etc. */
 
@@ -714,11 +711,17 @@ PyAPI_FUNC(Py_ssize_t) _Py_GetRefTotal(void);
                 _Py_NegativeRefcount(__FILE__, __LINE__,        \
                                      (PyObject *)(OP));         \
 }
+/* Py_REF_DEBUG also controls the display of refcounts and memory block
+ * allocations at the interactive prompt and at interpreter shutdown
+ */
+PyAPI_FUNC(void) _PyDebug_PrintTotalRefs(void);
+#define _PY_DEBUG_PRINT_TOTAL_REFS() _PyDebug_PrintTotalRefs()
 #else
 #define _Py_INC_REFTOTAL
 #define _Py_DEC_REFTOTAL
 #define _Py_REF_DEBUG_COMMA
 #define _Py_CHECK_REFCNT(OP)    /* a semicolon */;
+#define _PY_DEBUG_PRINT_TOTAL_REFS()
 #endif /* Py_REF_DEBUG */
 
 #ifdef COUNT_ALLOCS
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 3f21b70..65b6d91 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -95,6 +95,7 @@ PyObject_{New, NewVar, Del}.
    the raw memory.
 */
 PyAPI_FUNC(void *) PyObject_Malloc(size_t size);
+PyAPI_FUNC(void *) PyObject_Calloc(size_t nelem, size_t elsize);
 PyAPI_FUNC(void *) PyObject_Realloc(void *ptr, size_t new_size);
 PyAPI_FUNC(void) PyObject_Free(void *ptr);
 
@@ -321,7 +322,8 @@ extern PyGC_Head *_PyGC_generation0;
         (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj)))
 #endif /* Py_LIMITED_API */
 
-PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t);
+PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t size);
+PyAPI_FUNC(PyObject *) _PyObject_GC_Calloc(size_t size);
 PyAPI_FUNC(PyObject *) _PyObject_GC_New(PyTypeObject *);
 PyAPI_FUNC(PyVarObject *) _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t);
 PyAPI_FUNC(void) PyObject_GC_Track(void *);
diff --git a/Include/opcode.h b/Include/opcode.h
index 0936f2d..0638b54 100644
--- a/Include/opcode.h
+++ b/Include/opcode.h
@@ -1,3 +1,4 @@
+/* Auto-generated by Tools/scripts/generate_opcode_h.py */
 #ifndef Py_OPCODE_H
 #define Py_OPCODE_H
 #ifdef __cplusplus
@@ -5,141 +6,111 @@ extern "C" {
 #endif
 
 
-/* Instruction opcodes for compiled code */
-
-#define POP_TOP         1
-#define ROT_TWO         2
-#define ROT_THREE       3
-#define DUP_TOP         4
-#define DUP_TOP_TWO     5
-#define NOP             9
-
-#define UNARY_POSITIVE  10
-#define UNARY_NEGATIVE  11
-#define UNARY_NOT       12
-
-#define UNARY_INVERT    15
-
-#define BINARY_POWER    19
-
-#define BINARY_MULTIPLY 20
-
-#define BINARY_MODULO   22
-#define BINARY_ADD      23
-#define BINARY_SUBTRACT 24
-#define BINARY_SUBSCR   25
-#define BINARY_FLOOR_DIVIDE 26
-#define BINARY_TRUE_DIVIDE 27
-#define INPLACE_FLOOR_DIVIDE 28
-#define INPLACE_TRUE_DIVIDE 29
-
-#define STORE_MAP       54
-#define INPLACE_ADD     55
-#define INPLACE_SUBTRACT        56
-#define INPLACE_MULTIPLY        57
-
-#define INPLACE_MODULO  59
-#define STORE_SUBSCR    60
-#define DELETE_SUBSCR   61
-
-#define BINARY_LSHIFT   62
-#define BINARY_RSHIFT   63
-#define BINARY_AND      64
-#define BINARY_XOR      65
-#define BINARY_OR       66
-#define INPLACE_POWER   67
-#define GET_ITER        68
-#define PRINT_EXPR      70
-#define LOAD_BUILD_CLASS 71
-#define YIELD_FROM      72
-
-#define INPLACE_LSHIFT  75
-#define INPLACE_RSHIFT  76
-#define INPLACE_AND     77
-#define INPLACE_XOR     78
-#define INPLACE_OR      79
-#define BREAK_LOOP      80
-#define WITH_CLEANUP    81
-
-#define RETURN_VALUE    83
-#define IMPORT_STAR     84
-
-#define YIELD_VALUE     86
-#define POP_BLOCK       87
-#define END_FINALLY     88
-#define POP_EXCEPT      89
-
-#define HAVE_ARGUMENT   90      /* Opcodes from here have an argument: */
-
-#define STORE_NAME      90      /* Index in name list */
-#define DELETE_NAME     91      /* "" */
-#define UNPACK_SEQUENCE 92      /* Number of sequence items */
-#define FOR_ITER        93
-#define UNPACK_EX       94      /* Num items before variable part +
-                                   (Num items after variable part << 8) */
-
-#define STORE_ATTR      95      /* Index in name list */
-#define DELETE_ATTR     96      /* "" */
-#define STORE_GLOBAL    97      /* "" */
-#define DELETE_GLOBAL   98      /* "" */
-
-#define LOAD_CONST      100     /* Index in const list */
-#define LOAD_NAME       101     /* Index in name list */
-#define BUILD_TUPLE     102     /* Number of tuple items */
-#define BUILD_LIST      103     /* Number of list items */
-#define BUILD_SET       104     /* Number of set items */
-#define BUILD_MAP       105     /* Always zero for now */
-#define LOAD_ATTR       106     /* Index in name list */
-#define COMPARE_OP      107     /* Comparison operator */
-#define IMPORT_NAME     108     /* Index in name list */
-#define IMPORT_FROM     109     /* Index in name list */
-
-#define JUMP_FORWARD    110     /* Number of bytes to skip */
-#define JUMP_IF_FALSE_OR_POP 111        /* Target byte offset from beginning of code */
-#define JUMP_IF_TRUE_OR_POP 112 /* "" */
-#define JUMP_ABSOLUTE   113     /* "" */
-#define POP_JUMP_IF_FALSE 114   /* "" */
-#define POP_JUMP_IF_TRUE 115    /* "" */
-
-#define LOAD_GLOBAL     116     /* Index in name list */
-
-#define CONTINUE_LOOP   119     /* Start of loop (absolute) */
-#define SETUP_LOOP      120     /* Target address (relative) */
-#define SETUP_EXCEPT    121     /* "" */
-#define SETUP_FINALLY   122     /* "" */
-
-#define LOAD_FAST       124     /* Local variable number */
-#define STORE_FAST      125     /* Local variable number */
-#define DELETE_FAST     126     /* Local variable number */
-
-#define RAISE_VARARGS   130     /* Number of raise arguments (1, 2 or 3) */
-/* CALL_FUNCTION_XXX opcodes defined below depend on this definition */
-#define CALL_FUNCTION   131     /* #args + (#kwargs<<8) */
-#define MAKE_FUNCTION   132     /* #defaults + #kwdefaults<<8 + #annotations<<16 */
-#define BUILD_SLICE     133     /* Number of items */
-
-#define MAKE_CLOSURE    134     /* same as MAKE_FUNCTION */
-#define LOAD_CLOSURE    135     /* Load free variable from closure */
-#define LOAD_DEREF      136     /* Load and dereference from closure cell */ 
-#define STORE_DEREF     137     /* Store into cell */ 
-#define DELETE_DEREF    138     /* Delete closure cell */ 
-
-/* The next 3 opcodes must be contiguous and satisfy
-   (CALL_FUNCTION_VAR - CALL_FUNCTION) & 3 == 1  */
-#define CALL_FUNCTION_VAR          140  /* #args + (#kwargs<<8) */
-#define CALL_FUNCTION_KW           141  /* #args + (#kwargs<<8) */
-#define CALL_FUNCTION_VAR_KW       142  /* #args + (#kwargs<<8) */
-
-#define SETUP_WITH 143
-
-/* Support for opargs more than 16 bits long */
-#define EXTENDED_ARG  144
-
-#define LIST_APPEND     145
-#define SET_ADD         146
-#define MAP_ADD         147
-
-#define LOAD_CLASSDEREF   148
+    /* Instruction opcodes for compiled code */
+#define POP_TOP             	1  
+#define ROT_TWO             	2  
+#define ROT_THREE           	3  
+#define DUP_TOP             	4  
+#define DUP_TOP_TWO         	5  
+#define NOP                 	9  
+#define UNARY_POSITIVE      	10 
+#define UNARY_NEGATIVE      	11 
+#define UNARY_NOT           	12 
+#define UNARY_INVERT        	15 
+#define BINARY_MATRIX_MULTIPLY	16 
+#define INPLACE_MATRIX_MULTIPLY	17 
+#define BINARY_POWER        	19 
+#define BINARY_MULTIPLY     	20 
+#define BINARY_MODULO       	22 
+#define BINARY_ADD          	23 
+#define BINARY_SUBTRACT     	24 
+#define BINARY_SUBSCR       	25 
+#define BINARY_FLOOR_DIVIDE 	26 
+#define BINARY_TRUE_DIVIDE  	27 
+#define INPLACE_FLOOR_DIVIDE	28 
+#define INPLACE_TRUE_DIVIDE 	29 
+#define STORE_MAP           	54 
+#define INPLACE_ADD         	55 
+#define INPLACE_SUBTRACT    	56 
+#define INPLACE_MULTIPLY    	57 
+#define INPLACE_MODULO      	59 
+#define STORE_SUBSCR        	60 
+#define DELETE_SUBSCR       	61 
+#define BINARY_LSHIFT       	62 
+#define BINARY_RSHIFT       	63 
+#define BINARY_AND          	64 
+#define BINARY_XOR          	65 
+#define BINARY_OR           	66 
+#define INPLACE_POWER       	67 
+#define GET_ITER            	68 
+#define PRINT_EXPR          	70 
+#define LOAD_BUILD_CLASS    	71 
+#define YIELD_FROM          	72 
+#define INPLACE_LSHIFT      	75 
+#define INPLACE_RSHIFT      	76 
+#define INPLACE_AND         	77 
+#define INPLACE_XOR         	78 
+#define INPLACE_OR          	79 
+#define BREAK_LOOP          	80 
+#define WITH_CLEANUP        	81 
+#define RETURN_VALUE        	83 
+#define IMPORT_STAR         	84 
+#define YIELD_VALUE         	86 
+#define POP_BLOCK           	87 
+#define END_FINALLY         	88 
+#define POP_EXCEPT          	89 
+#define HAVE_ARGUMENT       	90 
+#define STORE_NAME          	90 
+#define DELETE_NAME         	91 
+#define UNPACK_SEQUENCE     	92 
+#define FOR_ITER            	93 
+#define UNPACK_EX           	94 
+#define STORE_ATTR          	95 
+#define DELETE_ATTR         	96 
+#define STORE_GLOBAL        	97 
+#define DELETE_GLOBAL       	98 
+#define LOAD_CONST          	100
+#define LOAD_NAME           	101
+#define BUILD_TUPLE         	102
+#define BUILD_LIST          	103
+#define BUILD_SET           	104
+#define BUILD_MAP           	105
+#define LOAD_ATTR           	106
+#define COMPARE_OP          	107
+#define IMPORT_NAME         	108
+#define IMPORT_FROM         	109
+#define JUMP_FORWARD        	110
+#define JUMP_IF_FALSE_OR_POP	111
+#define JUMP_IF_TRUE_OR_POP 	112
+#define JUMP_ABSOLUTE       	113
+#define POP_JUMP_IF_FALSE   	114
+#define POP_JUMP_IF_TRUE    	115
+#define LOAD_GLOBAL         	116
+#define CONTINUE_LOOP       	119
+#define SETUP_LOOP          	120
+#define SETUP_EXCEPT        	121
+#define SETUP_FINALLY       	122
+#define LOAD_FAST           	124
+#define STORE_FAST          	125
+#define DELETE_FAST         	126
+#define RAISE_VARARGS       	130
+#define CALL_FUNCTION       	131
+#define MAKE_FUNCTION       	132
+#define BUILD_SLICE         	133
+#define MAKE_CLOSURE        	134
+#define LOAD_CLOSURE        	135
+#define LOAD_DEREF          	136
+#define STORE_DEREF         	137
+#define DELETE_DEREF        	138
+#define CALL_FUNCTION_VAR   	140
+#define CALL_FUNCTION_KW    	141
+#define CALL_FUNCTION_VAR_KW	142
+#define SETUP_WITH          	143
+#define EXTENDED_ARG        	144
+#define LIST_APPEND         	145
+#define SET_ADD             	146
+#define MAP_ADD             	147
+#define LOAD_CLASSDEREF     	148
 
 /* EXCEPT_HANDLER is a special, implicit block type which is created when
    entering an except handler. It is not an opcode but we define it here
@@ -148,8 +119,9 @@ extern "C" {
 #define EXCEPT_HANDLER 257
 
 
-enum cmp_op {PyCmp_LT=Py_LT, PyCmp_LE=Py_LE, PyCmp_EQ=Py_EQ, PyCmp_NE=Py_NE, PyCmp_GT=Py_GT, PyCmp_GE=Py_GE,
-             PyCmp_IN, PyCmp_NOT_IN, PyCmp_IS, PyCmp_IS_NOT, PyCmp_EXC_MATCH, PyCmp_BAD};
+enum cmp_op {PyCmp_LT=Py_LT, PyCmp_LE=Py_LE, PyCmp_EQ=Py_EQ, PyCmp_NE=Py_NE,
+                PyCmp_GT=Py_GT, PyCmp_GE=Py_GE, PyCmp_IN, PyCmp_NOT_IN,
+                PyCmp_IS, PyCmp_IS_NOT, PyCmp_EXC_MATCH, PyCmp_BAD};
 
 #define HAS_ARG(op) ((op) >= HAVE_ARGUMENT)
 
diff --git a/Include/osdefs.h b/Include/osdefs.h
index 0c2e34b..bd84c1c 100644
--- a/Include/osdefs.h
+++ b/Include/osdefs.h
@@ -7,15 +7,12 @@ extern "C" {
 
 /* Operating system dependencies */
 
-/* Mod by chrish: QNX has WATCOM, but isn't DOS */
-#if !defined(__QNX__)
-#if defined(MS_WINDOWS) || defined(__BORLANDC__) || defined(__WATCOMC__) || defined(__DJGPP__)
+#ifdef MS_WINDOWS
 #define SEP L'\\'
 #define ALTSEP L'/'
 #define MAXPATHLEN 256
 #define DELIM L';'
 #endif
-#endif
 
 /* Filename separator */
 #ifndef SEP
diff --git a/Include/patchlevel.h b/Include/patchlevel.h
index f884cd1..1023a8e 100644
--- a/Include/patchlevel.h
+++ b/Include/patchlevel.h
@@ -17,13 +17,13 @@
 /* Version parsed out into numeric values */
 /*--start constants--*/
 #define PY_MAJOR_VERSION	3
-#define PY_MINOR_VERSION	4
-#define PY_MICRO_VERSION	3
-#define PY_RELEASE_LEVEL	PY_RELEASE_LEVEL_FINAL
-#define PY_RELEASE_SERIAL	0
+#define PY_MINOR_VERSION	5
+#define PY_MICRO_VERSION	0
+#define PY_RELEASE_LEVEL	PY_RELEASE_LEVEL_ALPHA
+#define PY_RELEASE_SERIAL	4
 
 /* Version as a string */
-#define PY_VERSION      	"3.4.3+"
+#define PY_VERSION      	"3.5.0a4+"
 /*--end constants--*/
 
 /* Version as a single 4-byte hex number, e.g. 0x010502B2 == 1.5.2b2.
diff --git a/Include/pyatomic.h b/Include/pyatomic.h
index d4e19e0..99816a5 100644
--- a/Include/pyatomic.h
+++ b/Include/pyatomic.h
@@ -1,14 +1,15 @@
-#ifndef Py_LIMITED_API
+/* Issue #23644: <stdatomic.h> is incompatible with C++, see:
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60932 */
+#if !defined(Py_LIMITED_API) && !defined(__cplusplus)
 #ifndef Py_ATOMIC_H
 #define Py_ATOMIC_H
-/* XXX: When compilers start offering a stdatomic.h with lock-free
-   atomic_int and atomic_address types, include that here and rewrite
-   the atomic operations in terms of it. */
 
 #include "dynamic_annotations.h"
 
-#ifdef __cplusplus
-extern "C" {
+#include "pyconfig.h"
+
+#if defined(HAVE_STD_ATOMIC)
+#include <stdatomic.h>
 #endif
 
 /* This is modeled after the atomics interface from C1x, according to
@@ -20,6 +21,76 @@ extern "C" {
  * Beware, the implementations here are deep magic.
  */
 
+#if defined(HAVE_STD_ATOMIC)
+
+typedef enum _Py_memory_order {
+    _Py_memory_order_relaxed = memory_order_relaxed,
+    _Py_memory_order_acquire = memory_order_acquire,
+    _Py_memory_order_release = memory_order_release,
+    _Py_memory_order_acq_rel = memory_order_acq_rel,
+    _Py_memory_order_seq_cst = memory_order_seq_cst
+} _Py_memory_order;
+
+typedef struct _Py_atomic_address {
+    _Atomic void *_value;
+} _Py_atomic_address;
+
+typedef struct _Py_atomic_int {
+    atomic_int _value;
+} _Py_atomic_int;
+
+#define _Py_atomic_signal_fence(/*memory_order*/ ORDER) \
+    atomic_signal_fence(ORDER)
+
+#define _Py_atomic_thread_fence(/*memory_order*/ ORDER) \
+    atomic_thread_fence(ORDER)
+
+#define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
+    atomic_store_explicit(&(ATOMIC_VAL)->_value, NEW_VAL, ORDER)
+
+#define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER) \
+    atomic_load_explicit(&(ATOMIC_VAL)->_value, ORDER)
+
+/* Use builtin atomic operations in GCC >= 4.7 */
+#elif defined(HAVE_BUILTIN_ATOMIC)
+
+typedef enum _Py_memory_order {
+    _Py_memory_order_relaxed = __ATOMIC_RELAXED,
+    _Py_memory_order_acquire = __ATOMIC_ACQUIRE,
+    _Py_memory_order_release = __ATOMIC_RELEASE,
+    _Py_memory_order_acq_rel = __ATOMIC_ACQ_REL,
+    _Py_memory_order_seq_cst = __ATOMIC_SEQ_CST
+} _Py_memory_order;
+
+typedef struct _Py_atomic_address {
+    void *_value;
+} _Py_atomic_address;
+
+typedef struct _Py_atomic_int {
+    int _value;
+} _Py_atomic_int;
+
+#define _Py_atomic_signal_fence(/*memory_order*/ ORDER) \
+    __atomic_signal_fence(ORDER)
+
+#define _Py_atomic_thread_fence(/*memory_order*/ ORDER) \
+    __atomic_thread_fence(ORDER)
+
+#define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
+    (assert((ORDER) == __ATOMIC_RELAXED                       \
+            || (ORDER) == __ATOMIC_SEQ_CST                    \
+            || (ORDER) == __ATOMIC_RELEASE),                  \
+     __atomic_store_n(&(ATOMIC_VAL)->_value, NEW_VAL, ORDER))
+
+#define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER)           \
+    (assert((ORDER) == __ATOMIC_RELAXED                       \
+            || (ORDER) == __ATOMIC_SEQ_CST                    \
+            || (ORDER) == __ATOMIC_ACQUIRE                    \
+            || (ORDER) == __ATOMIC_CONSUME),                  \
+     __atomic_load_n(&(ATOMIC_VAL)->_value, ORDER))
+
+#else
+
 typedef enum _Py_memory_order {
     _Py_memory_order_relaxed,
     _Py_memory_order_acquire,
@@ -162,6 +233,7 @@ _Py_ANNOTATE_MEMORY_ORDER(const volatile void *address, _Py_memory_order order)
     ((ATOMIC_VAL)->_value)
 
 #endif  /* !gcc x86 */
+#endif
 
 /* Standardized shortcuts. */
 #define _Py_atomic_store(ATOMIC_VAL, NEW_VAL) \
@@ -176,9 +248,5 @@ _Py_ANNOTATE_MEMORY_ORDER(const volatile void *address, _Py_memory_order order)
 #define _Py_atomic_load_relaxed(ATOMIC_VAL) \
     _Py_atomic_load_explicit(ATOMIC_VAL, _Py_memory_order_relaxed)
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif  /* Py_ATOMIC_H */
 #endif  /* Py_LIMITED_API */
diff --git a/Include/pydebug.h b/Include/pydebug.h
index 8fe9818..19bec2b 100644
--- a/Include/pydebug.h
+++ b/Include/pydebug.h
@@ -5,6 +5,8 @@
 extern "C" {
 #endif
 
+/* These global variable are defined in pylifecycle.c */
+/* XXX (ncoghlan): move these declarations to pylifecycle.h? */
 PyAPI_DATA(int) Py_DebugFlag;
 PyAPI_DATA(int) Py_VerboseFlag;
 PyAPI_DATA(int) Py_QuietFlag;
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 02f65d6..8a7e4f4 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -99,6 +99,7 @@ PyAPI_FUNC(void) PyErr_SetExcInfo(PyObject *, PyObject *, PyObject *);
 #define _Py_NO_RETURN
 #endif
 
+/* Defined in Python/pylifecycle.c */
 PyAPI_FUNC(void) Py_FatalError(const char *message) _Py_NO_RETURN;
 
 #if defined(Py_DEBUG) || defined(Py_LIMITED_API)
@@ -244,6 +245,12 @@ PyAPI_FUNC(PyObject *) PyErr_Format(
     const char *format,   /* ASCII-encoded string  */
     ...
     );
+#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03050000
+PyAPI_FUNC(PyObject *) PyErr_FormatV(
+    PyObject *exception,
+    const char *format,
+    va_list vargs);
+#endif
 
 #ifdef MS_WINDOWS
 PyAPI_FUNC(PyObject *) PyErr_SetFromWindowsErrWithFilename(
diff --git a/Include/pylifecycle.h b/Include/pylifecycle.h
new file mode 100644
index 0000000..ccdebe2
--- /dev/null
+++ b/Include/pylifecycle.h
@@ -0,0 +1,124 @@
+
+/* Interfaces to configure, query, create & destroy the Python runtime */
+
+#ifndef Py_PYLIFECYCLE_H
+#define Py_PYLIFECYCLE_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+PyAPI_FUNC(void) Py_SetProgramName(wchar_t *);
+PyAPI_FUNC(wchar_t *) Py_GetProgramName(void);
+
+PyAPI_FUNC(void) Py_SetPythonHome(wchar_t *);
+PyAPI_FUNC(wchar_t *) Py_GetPythonHome(void);
+
+#ifndef Py_LIMITED_API
+/* Only used by applications that embed the interpreter and need to
+ * override the standard encoding determination mechanism
+ */
+PyAPI_FUNC(int) Py_SetStandardStreamEncoding(const char *encoding,
+                                             const char *errors);
+#endif
+
+PyAPI_FUNC(void) Py_Initialize(void);
+PyAPI_FUNC(void) Py_InitializeEx(int);
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _Py_InitializeEx_Private(int, int);
+#endif
+PyAPI_FUNC(void) Py_Finalize(void);
+PyAPI_FUNC(int) Py_IsInitialized(void);
+PyAPI_FUNC(PyThreadState *) Py_NewInterpreter(void);
+PyAPI_FUNC(void) Py_EndInterpreter(PyThreadState *);
+
+
+/* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
+ * exit functions.
+ */
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _Py_PyAtExit(void (*func)(void));
+#endif
+PyAPI_FUNC(int) Py_AtExit(void (*func)(void));
+
+PyAPI_FUNC(void) Py_Exit(int);
+
+/* Restore signals that the interpreter has called SIG_IGN on to SIG_DFL. */
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _Py_RestoreSignals(void);
+
+PyAPI_FUNC(int) Py_FdIsInteractive(FILE *, const char *);
+#endif
+
+/* Bootstrap __main__ (defined in Modules/main.c) */
+PyAPI_FUNC(int) Py_Main(int argc, wchar_t **argv);
+
+/* In getpath.c */
+PyAPI_FUNC(wchar_t *) Py_GetProgramFullPath(void);
+PyAPI_FUNC(wchar_t *) Py_GetPrefix(void);
+PyAPI_FUNC(wchar_t *) Py_GetExecPrefix(void);
+PyAPI_FUNC(wchar_t *) Py_GetPath(void);
+PyAPI_FUNC(void)      Py_SetPath(const wchar_t *);
+#ifdef MS_WINDOWS
+int _Py_CheckPython3();
+#endif
+
+/* In their own files */
+PyAPI_FUNC(const char *) Py_GetVersion(void);
+PyAPI_FUNC(const char *) Py_GetPlatform(void);
+PyAPI_FUNC(const char *) Py_GetCopyright(void);
+PyAPI_FUNC(const char *) Py_GetCompiler(void);
+PyAPI_FUNC(const char *) Py_GetBuildInfo(void);
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(const char *) _Py_hgidentifier(void);
+PyAPI_FUNC(const char *) _Py_hgversion(void);
+#endif
+
+/* Internal -- various one-time initializations */
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(PyObject *) _PyBuiltin_Init(void);
+PyAPI_FUNC(PyObject *) _PySys_Init(void);
+PyAPI_FUNC(void) _PyImport_Init(void);
+PyAPI_FUNC(void) _PyExc_Init(PyObject * bltinmod);
+PyAPI_FUNC(void) _PyImportHooks_Init(void);
+PyAPI_FUNC(int) _PyFrame_Init(void);
+PyAPI_FUNC(int) _PyFloat_Init(void);
+PyAPI_FUNC(int) PyByteArray_Init(void);
+PyAPI_FUNC(void) _PyRandom_Init(void);
+#endif
+
+/* Various internal finalizers */
+#ifndef Py_LIMITED_API
+PyAPI_FUNC(void) _PyExc_Fini(void);
+PyAPI_FUNC(void) _PyImport_Fini(void);
+PyAPI_FUNC(void) PyMethod_Fini(void);
+PyAPI_FUNC(void) PyFrame_Fini(void);
+PyAPI_FUNC(void) PyCFunction_Fini(void);
+PyAPI_FUNC(void) PyDict_Fini(void);
+PyAPI_FUNC(void) PyTuple_Fini(void);
+PyAPI_FUNC(void) PyList_Fini(void);
+PyAPI_FUNC(void) PySet_Fini(void);
+PyAPI_FUNC(void) PyBytes_Fini(void);
+PyAPI_FUNC(void) PyByteArray_Fini(void);
+PyAPI_FUNC(void) PyFloat_Fini(void);
+PyAPI_FUNC(void) PyOS_FiniInterrupts(void);
+PyAPI_FUNC(void) _PyGC_DumpShutdownStats(void);
+PyAPI_FUNC(void) _PyGC_Fini(void);
+PyAPI_FUNC(void) PySlice_Fini(void);
+PyAPI_FUNC(void) _PyType_Fini(void);
+PyAPI_FUNC(void) _PyRandom_Fini(void);
+
+PyAPI_DATA(PyThreadState *) _Py_Finalizing;
+#endif
+
+/* Signals */
+typedef void (*PyOS_sighandler_t)(int);
+PyAPI_FUNC(PyOS_sighandler_t) PyOS_getsig(int);
+PyAPI_FUNC(PyOS_sighandler_t) PyOS_setsig(int, PyOS_sighandler_t);
+
+/* Random */
+PyAPI_FUNC(int) _PyOS_URandom (void *buffer, Py_ssize_t size);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_PYLIFECYCLE_H */
diff --git a/Include/pymacro.h b/Include/pymacro.h
index 7997c55..3f6f5dc 100644
--- a/Include/pymacro.h
+++ b/Include/pymacro.h
@@ -1,13 +1,26 @@
 #ifndef Py_PYMACRO_H
 #define Py_PYMACRO_H
 
+/* Minimum value between x and y */
 #define Py_MIN(x, y) (((x) > (y)) ? (y) : (x))
+
+/* Maximum value between x and y */
 #define Py_MAX(x, y) (((x) > (y)) ? (x) : (y))
 
+/* Absolute value of the number x */
+#define Py_ABS(x) ((x) < 0 ? -(x) : (x))
+
+#define _Py_XSTRINGIFY(x) #x
+
+/* Convert the argument to a string. For example, Py_STRINGIFY(123) is replaced
+   with "123" by the preprocessor. Defines are also replaced by their value.
+   For example Py_STRINGIFY(__LINE__) is replaced by the line number, not
+   by "__LINE__". */
+#define Py_STRINGIFY(x) _Py_XSTRINGIFY(x)
+
 /* Argument must be a char or an int in [-128, 127] or [0, 255]. */
 #define Py_CHARMASK(c) ((unsigned char)((c) & 0xff))
 
-
 /* Assert a build-time dependency, as an expression.
 
    Your compile will fail if the condition isn't true, or can't be evaluated
diff --git a/Include/pymem.h b/Include/pymem.h
index 2372b86..043db64 100644
--- a/Include/pymem.h
+++ b/Include/pymem.h
@@ -13,6 +13,7 @@ extern "C" {
 
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(void *) PyMem_RawMalloc(size_t size);
+PyAPI_FUNC(void *) PyMem_RawCalloc(size_t nelem, size_t elsize);
 PyAPI_FUNC(void *) PyMem_RawRealloc(void *ptr, size_t new_size);
 PyAPI_FUNC(void) PyMem_RawFree(void *ptr);
 #endif
@@ -57,6 +58,7 @@ PyAPI_FUNC(void) PyMem_RawFree(void *ptr);
 */
 
 PyAPI_FUNC(void *) PyMem_Malloc(size_t size);
+PyAPI_FUNC(void *) PyMem_Calloc(size_t nelem, size_t elsize);
 PyAPI_FUNC(void *) PyMem_Realloc(void *ptr, size_t new_size);
 PyAPI_FUNC(void) PyMem_Free(void *ptr);
 
@@ -126,22 +128,25 @@ typedef enum {
 } PyMemAllocatorDomain;
 
 typedef struct {
-    /* user context passed as the first argument to the 3 functions */
+    /* user context passed as the first argument to the 4 functions */
     void *ctx;
 
     /* allocate a memory block */
     void* (*malloc) (void *ctx, size_t size);
 
+    /* allocate a memory block initialized by zeros */
+    void* (*calloc) (void *ctx, size_t nelem, size_t elsize);
+
     /* allocate or resize a memory block */
     void* (*realloc) (void *ctx, void *ptr, size_t new_size);
 
     /* release a memory block */
     void (*free) (void *ctx, void *ptr);
-} PyMemAllocator;
+} PyMemAllocatorEx;
 
 /* Get the memory block allocator of the specified domain. */
 PyAPI_FUNC(void) PyMem_GetAllocator(PyMemAllocatorDomain domain,
-                                    PyMemAllocator *allocator);
+                                    PyMemAllocatorEx *allocator);
 
 /* Set the memory block allocator of the specified domain.
 
@@ -155,7 +160,7 @@ PyAPI_FUNC(void) PyMem_GetAllocator(PyMemAllocatorDomain domain,
    PyMem_SetupDebugHooks() function must be called to reinstall the debug hooks
    on top on the new allocator. */
 PyAPI_FUNC(void) PyMem_SetAllocator(PyMemAllocatorDomain domain,
-                                    PyMemAllocator *allocator);
+                                    PyMemAllocatorEx *allocator);
 
 /* Setup hooks to detect bugs in the following Python memory allocator
    functions:
diff --git a/Include/pyport.h b/Include/pyport.h
index b29f9bd..66e00d4 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -357,28 +357,6 @@ typedef int Py_ssize_clean_t;
  * stat() and fstat() fiddling *
  *******************************/
 
-/* We expect that stat and fstat exist on most systems.
- *  It's confirmed on Unix, Mac and Windows.
- *  If you don't have them, add
- *      #define DONT_HAVE_STAT
- * and/or
- *      #define DONT_HAVE_FSTAT
- * to your pyconfig.h. Python code beyond this should check HAVE_STAT and
- * HAVE_FSTAT instead.
- * Also
- *      #define HAVE_SYS_STAT_H
- * if <sys/stat.h> exists on your platform, and
- *      #define HAVE_STAT_H
- * if <stat.h> does.
- */
-#ifndef DONT_HAVE_STAT
-#define HAVE_STAT
-#endif
-
-#ifndef DONT_HAVE_FSTAT
-#define HAVE_FSTAT
-#endif
-
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #elif defined(HAVE_STAT_H)
@@ -588,6 +566,25 @@ extern "C" {
     } while (0)
 #endif
 
+#ifdef HAVE_GCC_ASM_FOR_MC68881
+#define HAVE_PY_SET_53BIT_PRECISION 1
+#define _Py_SET_53BIT_PRECISION_HEADER \
+  unsigned int old_fpcr, new_fpcr
+#define _Py_SET_53BIT_PRECISION_START					\
+  do {									\
+    __asm__ ("fmove.l %%fpcr,%0" : "=g" (old_fpcr));			\
+    /* Set double precision / round to nearest.  */			\
+    new_fpcr = (old_fpcr & ~0xf0) | 0x80;				\
+    if (new_fpcr != old_fpcr)						\
+      __asm__ volatile ("fmove.l %0,%%fpcr" : : "g" (new_fpcr));	\
+  } while (0)
+#define _Py_SET_53BIT_PRECISION_END					\
+  do {									\
+    if (new_fpcr != old_fpcr)						\
+      __asm__ volatile ("fmove.l %0,%%fpcr" : : "g" (old_fpcr));	\
+  } while (0)
+#endif
+
 /* default definitions are empty */
 #ifndef HAVE_PY_SET_53BIT_PRECISION
 #define _Py_SET_53BIT_PRECISION_HEADER
@@ -880,4 +877,24 @@ extern pid_t forkpty(int *, char *, struct termios *, struct winsize *);
 #define PY_LITTLE_ENDIAN 1
 #endif
 
+#ifdef Py_BUILD_CORE 
+/*
+ * Macros to protect CRT calls against instant termination when passed an
+ * invalid parameter (issue23524).
+ */
+#if defined _MSC_VER && _MSC_VER >= 1900
+
+extern _invalid_parameter_handler _Py_silent_invalid_parameter_handler;
+#define _Py_BEGIN_SUPPRESS_IPH { _invalid_parameter_handler _Py_old_handler = \
+    _set_thread_local_invalid_parameter_handler(_Py_silent_invalid_parameter_handler);
+#define _Py_END_SUPPRESS_IPH _set_thread_local_invalid_parameter_handler(_Py_old_handler); }
+
+#else
+
+#define _Py_BEGIN_SUPPRESS_IPH
+#define _Py_END_SUPPRESS_IPH
+
+#endif /* _MSC_VER >= 1900 */
+#endif /* Py_BUILD_CORE */
+
 #endif /* Py_PYPORT_H */
diff --git a/Include/pystate.h b/Include/pystate.h
index 4992c22..8539b65 100644
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -174,12 +174,16 @@ PyAPI_FUNC(int) PyThreadState_SetAsyncExc(long, PyObject *);
 /* Variable and macro for in-line access to current thread state */
 
 /* Assuming the current thread holds the GIL, this is the
-   PyThreadState for the current thread. */
-#ifndef Py_LIMITED_API
+   PyThreadState for the current thread.
+
+   Issue #23644: pyatomic.h is incompatible with C++ (yet). Disable
+   PyThreadState_GET() optimization: declare it as an alias to
+   PyThreadState_Get(), as done for limited API. */
+#if !defined(Py_LIMITED_API) && !defined(__cplusplus)
 PyAPI_DATA(_Py_atomic_address) _PyThreadState_Current;
 #endif
 
-#if defined(Py_DEBUG) || defined(Py_LIMITED_API)
+#if defined(Py_DEBUG) || defined(Py_LIMITED_API) || defined(__cplusplus)
 #define PyThreadState_GET() PyThreadState_Get()
 #else
 #define PyThreadState_GET() \
diff --git a/Include/pythonrun.h b/Include/pythonrun.h
index 2fc5578..1d9b71b 100644
--- a/Include/pythonrun.h
+++ b/Include/pythonrun.h
@@ -22,30 +22,6 @@ typedef struct {
 } PyCompilerFlags;
 #endif
 
-PyAPI_FUNC(void) Py_SetProgramName(wchar_t *);
-PyAPI_FUNC(wchar_t *) Py_GetProgramName(void);
-
-PyAPI_FUNC(void) Py_SetPythonHome(wchar_t *);
-PyAPI_FUNC(wchar_t *) Py_GetPythonHome(void);
-
-#ifndef Py_LIMITED_API
-/* Only used by applications that embed the interpreter and need to
- * override the standard encoding determination mechanism
- */
-PyAPI_FUNC(int) Py_SetStandardStreamEncoding(const char *encoding,
-                                             const char *errors);
-#endif
-
-PyAPI_FUNC(void) Py_Initialize(void);
-PyAPI_FUNC(void) Py_InitializeEx(int);
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(void) _Py_InitializeEx_Private(int, int);
-#endif
-PyAPI_FUNC(void) Py_Finalize(void);
-PyAPI_FUNC(int) Py_IsInitialized(void);
-PyAPI_FUNC(PyThreadState *) Py_NewInterpreter(void);
-PyAPI_FUNC(void) Py_EndInterpreter(PyThreadState *);
-
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) PyRun_SimpleStringFlags(const char *, PyCompilerFlags *);
 PyAPI_FUNC(int) PyRun_AnyFileFlags(FILE *, const char *, PyCompilerFlags *);
@@ -166,26 +142,6 @@ PyAPI_FUNC(void) PyErr_Print(void);
 PyAPI_FUNC(void) PyErr_PrintEx(int);
 PyAPI_FUNC(void) PyErr_Display(PyObject *, PyObject *, PyObject *);
 
-/* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
- * exit functions.
- */
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(void) _Py_PyAtExit(void (*func)(void));
-#endif
-PyAPI_FUNC(int) Py_AtExit(void (*func)(void));
-
-PyAPI_FUNC(void) Py_Exit(int);
-
-/* Restore signals that the interpreter has called SIG_IGN on to SIG_DFL. */
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(void) _Py_RestoreSignals(void);
-
-PyAPI_FUNC(int) Py_FdIsInteractive(FILE *, const char *);
-#endif
-
-/* Bootstrap */
-PyAPI_FUNC(int) Py_Main(int argc, wchar_t **argv);
-
 #ifndef Py_LIMITED_API
 /* Use macros for a bunch of old variants */
 #define PyRun_String(str, s, g, l) PyRun_StringFlags(str, s, g, l, NULL)
@@ -207,64 +163,6 @@ PyAPI_FUNC(int) Py_Main(int argc, wchar_t **argv);
     PyRun_FileExFlags(fp, p, s, g, l, 0, flags)
 #endif
 
-/* In getpath.c */
-PyAPI_FUNC(wchar_t *) Py_GetProgramFullPath(void);
-PyAPI_FUNC(wchar_t *) Py_GetPrefix(void);
-PyAPI_FUNC(wchar_t *) Py_GetExecPrefix(void);
-PyAPI_FUNC(wchar_t *) Py_GetPath(void);
-PyAPI_FUNC(void)      Py_SetPath(const wchar_t *);
-#ifdef MS_WINDOWS
-int _Py_CheckPython3();
-#endif
-
-/* In their own files */
-PyAPI_FUNC(const char *) Py_GetVersion(void);
-PyAPI_FUNC(const char *) Py_GetPlatform(void);
-PyAPI_FUNC(const char *) Py_GetCopyright(void);
-PyAPI_FUNC(const char *) Py_GetCompiler(void);
-PyAPI_FUNC(const char *) Py_GetBuildInfo(void);
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(const char *) _Py_hgidentifier(void);
-PyAPI_FUNC(const char *) _Py_hgversion(void);
-#endif
-
-/* Internal -- various one-time initializations */
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(PyObject *) _PyBuiltin_Init(void);
-PyAPI_FUNC(PyObject *) _PySys_Init(void);
-PyAPI_FUNC(void) _PyImport_Init(void);
-PyAPI_FUNC(void) _PyExc_Init(PyObject * bltinmod);
-PyAPI_FUNC(void) _PyImportHooks_Init(void);
-PyAPI_FUNC(int) _PyFrame_Init(void);
-PyAPI_FUNC(int) _PyFloat_Init(void);
-PyAPI_FUNC(int) PyByteArray_Init(void);
-PyAPI_FUNC(void) _PyRandom_Init(void);
-#endif
-
-/* Various internal finalizers */
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(void) _PyExc_Fini(void);
-PyAPI_FUNC(void) _PyImport_Fini(void);
-PyAPI_FUNC(void) PyMethod_Fini(void);
-PyAPI_FUNC(void) PyFrame_Fini(void);
-PyAPI_FUNC(void) PyCFunction_Fini(void);
-PyAPI_FUNC(void) PyDict_Fini(void);
-PyAPI_FUNC(void) PyTuple_Fini(void);
-PyAPI_FUNC(void) PyList_Fini(void);
-PyAPI_FUNC(void) PySet_Fini(void);
-PyAPI_FUNC(void) PyBytes_Fini(void);
-PyAPI_FUNC(void) PyByteArray_Fini(void);
-PyAPI_FUNC(void) PyFloat_Fini(void);
-PyAPI_FUNC(void) PyOS_FiniInterrupts(void);
-PyAPI_FUNC(void) _PyGC_DumpShutdownStats(void);
-PyAPI_FUNC(void) _PyGC_Fini(void);
-PyAPI_FUNC(void) PySlice_Fini(void);
-PyAPI_FUNC(void) _PyType_Fini(void);
-PyAPI_FUNC(void) _PyRandom_Fini(void);
-
-PyAPI_DATA(PyThreadState *) _Py_Finalizing;
-#endif
-
 /* Stuff with no proper home (yet) */
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(char *) PyOS_Readline(FILE *, FILE *, const char *);
@@ -290,14 +188,6 @@ PyAPI_DATA(PyThreadState*) _PyOS_ReadlineTState;
 PyAPI_FUNC(int) PyOS_CheckStack(void);
 #endif
 
-/* Signals */
-typedef void (*PyOS_sighandler_t)(int);
-PyAPI_FUNC(PyOS_sighandler_t) PyOS_getsig(int);
-PyAPI_FUNC(PyOS_sighandler_t) PyOS_setsig(int, PyOS_sighandler_t);
-
-/* Random */
-PyAPI_FUNC(int) _PyOS_URandom (void *buffer, Py_ssize_t size);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/Include/pytime.h b/Include/pytime.h
index b0fc6d0..027c3d8 100644
--- a/Include/pytime.h
+++ b/Include/pytime.h
@@ -13,60 +13,26 @@ functions and constants
 extern "C" {
 #endif
 
-#ifdef HAVE_GETTIMEOFDAY
-typedef struct timeval _PyTime_timeval;
+#ifdef PY_INT64_T
+/* _PyTime_t: Python timestamp with subsecond precision. It can be used to
+   store a duration, and so indirectly a date (related to another date, like
+   UNIX epoch). */
+typedef PY_INT64_T _PyTime_t;
+#define _PyTime_MIN PY_LLONG_MIN
+#define _PyTime_MAX PY_LLONG_MAX
 #else
-typedef struct {
-    time_t       tv_sec;   /* seconds since Jan. 1, 1970 */
-    long         tv_usec;  /* and microseconds */
-} _PyTime_timeval;
+#  error "_PyTime_t need signed 64-bit integer type"
 #endif
 
-/* Structure used by time.get_clock_info() */
-typedef struct {
-    const char *implementation;
-    int monotonic;
-    int adjustable;
-    double resolution;
-} _Py_clock_info_t;
-
-/* Similar to POSIX gettimeofday but cannot fail.  If system gettimeofday
- * fails or is not available, fall back to lower resolution clocks.
- */
-PyAPI_FUNC(void) _PyTime_gettimeofday(_PyTime_timeval *tp);
-
-/* Similar to _PyTime_gettimeofday() but retrieve also information on the
- * clock used to get the current time. */
-PyAPI_FUNC(void) _PyTime_gettimeofday_info(
-    _PyTime_timeval *tp,
-    _Py_clock_info_t *info);
-
-#define _PyTime_ADD_SECONDS(tv, interval) \
-do { \
-    tv.tv_usec += (long) (((long) interval - interval) * 1000000); \
-    tv.tv_sec += (time_t) interval + (time_t) (tv.tv_usec / 1000000); \
-    tv.tv_usec %= 1000000; \
-} while (0)
-
-#define _PyTime_INTERVAL(tv_start, tv_end) \
-    ((tv_end.tv_sec - tv_start.tv_sec) + \
-     (tv_end.tv_usec - tv_start.tv_usec) * 0.000001)
-
-#ifndef Py_LIMITED_API
-
 typedef enum {
-    /* Round towards zero. */
-    _PyTime_ROUND_DOWN=0,
-    /* Round away from zero. */
-    _PyTime_ROUND_UP
+    /* Round towards minus infinity (-inf).
+       For example, used to read a clock. */
+    _PyTime_ROUND_FLOOR=0,
+    /* Round towards infinity (+inf).
+       For example, used for timeout to wait "at least" N seconds. */
+    _PyTime_ROUND_CEILING
 } _PyTime_round_t;
 
-/* Convert a number of seconds, int or float, to time_t. */
-PyAPI_FUNC(int) _PyTime_ObjectToTime_t(
-    PyObject *obj,
-    time_t *sec,
-    _PyTime_round_t);
-
 /* Convert a time_t to a PyLong. */
 PyAPI_FUNC(PyObject *) _PyLong_FromTime_t(
     time_t sec);
@@ -75,6 +41,12 @@ PyAPI_FUNC(PyObject *) _PyLong_FromTime_t(
 PyAPI_FUNC(time_t) _PyLong_AsTime_t(
     PyObject *obj);
 
+/* Convert a number of seconds, int or float, to time_t. */
+PyAPI_FUNC(int) _PyTime_ObjectToTime_t(
+    PyObject *obj,
+    time_t *sec,
+    _PyTime_round_t);
+
 /* Convert a number of seconds, int or float, to a timeval structure.
    usec is in the range [0; 999999] and rounded towards zero.
    For example, -1.2 is converted to (-2, 800000). */
@@ -92,10 +64,114 @@ PyAPI_FUNC(int) _PyTime_ObjectToTimespec(
     time_t *sec,
     long *nsec,
     _PyTime_round_t);
+
+
+/* Create a timestamp from a number of seconds. */
+PyAPI_FUNC(_PyTime_t) _PyTime_FromSeconds(int seconds);
+
+/* Macro to create a timestamp from a number of seconds, no integer overflow.
+   Only use the macro for small values, prefer _PyTime_FromSeconds(). */
+#define _PYTIME_FROMSECONDS(seconds) \
+            ((_PyTime_t)(seconds) * (1000 * 1000 * 1000))
+
+/* Create a timestamp from a number of nanoseconds. */
+PyAPI_FUNC(_PyTime_t) _PyTime_FromNanoseconds(PY_LONG_LONG ns);
+
+/* Convert a number of seconds (Python float or int) to a timetamp.
+   Raise an exception and return -1 on error, return 0 on success. */
+PyAPI_FUNC(int) _PyTime_FromSecondsObject(_PyTime_t *t,
+    PyObject *obj,
+    _PyTime_round_t round);
+
+/* Convert a number of milliseconds (Python float or int, 10^-3) to a timetamp.
+   Raise an exception and return -1 on error, return 0 on success. */
+PyAPI_FUNC(int) _PyTime_FromMillisecondsObject(_PyTime_t *t,
+    PyObject *obj,
+    _PyTime_round_t round);
+
+/* Convert a timestamp to a number of seconds as a C double. */
+PyAPI_FUNC(double) _PyTime_AsSecondsDouble(_PyTime_t t);
+
+/* Convert timestamp to a number of milliseconds (10^-3 seconds). */
+PyAPI_FUNC(_PyTime_t) _PyTime_AsMilliseconds(_PyTime_t t,
+    _PyTime_round_t round);
+
+/* Convert timestamp to a number of microseconds (10^-6 seconds). */
+PyAPI_FUNC(_PyTime_t) _PyTime_AsMicroseconds(_PyTime_t t,
+    _PyTime_round_t round);
+
+/* Convert timestamp to a number of nanoseconds (10^-9 seconds) as a Python int
+   object. */
+PyAPI_FUNC(PyObject *) _PyTime_AsNanosecondsObject(_PyTime_t t);
+
+/* Convert a timestamp to a timeval structure (microsecond resolution).
+   tv_usec is always positive.
+   Raise an exception and return -1 if the conversion overflowed,
+   return 0 on success. */
+PyAPI_FUNC(int) _PyTime_AsTimeval(_PyTime_t t,
+    struct timeval *tv,
+    _PyTime_round_t round);
+
+/* Similar to _PyTime_AsTimeval(), but don't raise an exception on error. */
+PyAPI_FUNC(int) _PyTime_AsTimeval_noraise(_PyTime_t t,
+    struct timeval *tv,
+    _PyTime_round_t round);
+
+#if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_KQUEUE)
+/* Convert a timestamp to a timespec structure (nanosecond resolution).
+   tv_nsec is always positive.
+   Raise an exception and return -1 on error, return 0 on success. */
+PyAPI_FUNC(int) _PyTime_AsTimespec(_PyTime_t t, struct timespec *ts);
 #endif
 
-/* Dummy to force linking. */
-PyAPI_FUNC(void) _PyTime_Init(void);
+/* Get the current time from the system clock.
+
+   The function cannot fail. _PyTime_Init() ensures that the system clock
+   works. */
+PyAPI_FUNC(_PyTime_t) _PyTime_GetSystemClock(void);
+
+/* Get the time of a monotonic clock, i.e. a clock that cannot go backwards.
+   The clock is not affected by system clock updates. The reference point of
+   the returned value is undefined, so that only the difference between the
+   results of consecutive calls is valid.
+
+   The function cannot fail. _PyTime_Init() ensures that a monotonic clock
+   is available and works. */
+PyAPI_FUNC(_PyTime_t) _PyTime_GetMonotonicClock(void);
+
+
+/* Structure used by time.get_clock_info() */
+typedef struct {
+    const char *implementation;
+    int monotonic;
+    int adjustable;
+    double resolution;
+} _Py_clock_info_t;
+
+/* Get the current time from the system clock.
+ * Fill clock information if info is not NULL.
+ * Raise an exception and return -1 on error, return 0 on success.
+ */
+PyAPI_FUNC(int) _PyTime_GetSystemClockWithInfo(
+    _PyTime_t *t,
+    _Py_clock_info_t *info);
+
+/* Get the time of a monotonic clock, i.e. a clock that cannot go backwards.
+   The clock is not affected by system clock updates. The reference point of
+   the returned value is undefined, so that only the difference between the
+   results of consecutive calls is valid.
+
+   Fill info (if set) with information of the function used to get the time.
+
+   Return 0 on success, raise an exception and return -1 on error. */
+PyAPI_FUNC(int) _PyTime_GetMonotonicClockWithInfo(
+    _PyTime_t *t,
+    _Py_clock_info_t *info);
+
+
+/* Initialize time.
+   Return 0 on success, raise an exception and return -1 on error. */
+PyAPI_FUNC(int) _PyTime_Init(void);
 
 #ifdef __cplusplus
 }
diff --git a/Include/setobject.h b/Include/setobject.h
index ae3f556..f17bc1b 100644
--- a/Include/setobject.h
+++ b/Include/setobject.h
@@ -6,38 +6,43 @@
 extern "C" {
 #endif
 
+#ifndef Py_LIMITED_API
 
-/*
-There are three kinds of slots in the table:
+/* There are three kinds of entries in the table:
 
 1. Unused:  key == NULL
 2. Active:  key != NULL and key != dummy
 3. Dummy:   key == dummy
 
-Note: .pop() abuses the hash field of an Unused or Dummy slot to
-hold a search finger.  The hash field of Unused or Dummy slots has
-no meaning otherwise.
+The hash field of Unused slots have no meaning.
+The hash field of Dummny slots are set to -1
+meaning that dummy entries can be detected by
+either entry->key==dummy or by entry->hash==-1.
 */
-#ifndef Py_LIMITED_API
+
 #define PySet_MINSIZE 8
 
 typedef struct {
-    /* Cached hash code of the key. */
     PyObject *key;
-    Py_hash_t hash;
+    Py_hash_t hash;             /* Cached hash code of the key */
 } setentry;
 
+/* The SetObject data structure is shared by set and frozenset objects.
+
+Invariant for sets:
+ - hash is -1
+
+Invariants for frozensets:
+ - data is immutable.
+ - hash is the hash of the frozenset or -1 if not computed yet.
 
-/*
-This data structure is shared by set and frozenset objects.
 */
 
-typedef struct _setobject PySetObject;
-struct _setobject {
+typedef struct {
     PyObject_HEAD
 
-    Py_ssize_t fill;  /* # Active + # Dummy */
-    Py_ssize_t used;  /* # Active */
+    Py_ssize_t fill;            /* Number active and dummy entries*/
+    Py_ssize_t used;            /* Number active entries */
 
     /* The table contains mask + 1 slots, and that's a power of 2.
      * We store the mask instead of the size because the mask is more
@@ -45,33 +50,42 @@ struct _setobject {
      */
     Py_ssize_t mask;
 
-    /* table points to smalltable for small tables, else to
-     * additional malloc'ed memory.  table is never NULL!  This rule
-     * saves repeated runtime null-tests.
+    /* The table points to a fixed-size smalltable for small tables
+     * or to additional malloc'ed memory for bigger tables.
+     * The table pointer is never NULL which saves us from repeated
+     * runtime null-tests.
      */
     setentry *table;
-    setentry *(*lookup)(PySetObject *so, PyObject *key, Py_hash_t hash);
-    Py_hash_t hash;             /* only used by frozenset objects */
-    setentry smalltable[PySet_MINSIZE];
+    Py_hash_t hash;             /* Only used by frozenset objects */
+    Py_ssize_t finger;          /* Search finger for pop() */
 
+    setentry smalltable[PySet_MINSIZE];
     PyObject *weakreflist;      /* List of weak references */
-};
-#endif /* Py_LIMITED_API */
+} PySetObject;
+
+#define PySet_GET_SIZE(so) (((PySetObject *)(so))->used)
+
+PyAPI_DATA(PyObject *) _PySet_Dummy;
+
+PyAPI_FUNC(int) _PySet_NextEntry(PyObject *set, Py_ssize_t *pos, PyObject **key, Py_hash_t *hash);
+PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);
+PyAPI_FUNC(int) PySet_ClearFreeList(void);
+
+#endif /* Section excluded by Py_LIMITED_API */
 
 PyAPI_DATA(PyTypeObject) PySet_Type;
 PyAPI_DATA(PyTypeObject) PyFrozenSet_Type;
 PyAPI_DATA(PyTypeObject) PySetIter_Type;
-#ifndef Py_LIMITED_API
-PyAPI_DATA(PyObject *) _PySet_Dummy;
-#endif
 
+PyAPI_FUNC(PyObject *) PySet_New(PyObject *);
+PyAPI_FUNC(PyObject *) PyFrozenSet_New(PyObject *);
 
-/* Invariants for frozensets:
- *     data is immutable.
- *     hash is the hash of the frozenset or -1 if not computed yet.
- * Invariants for sets:
- *     hash is -1
- */
+PyAPI_FUNC(int) PySet_Add(PyObject *set, PyObject *key);
+PyAPI_FUNC(int) PySet_Clear(PyObject *set);
+PyAPI_FUNC(int) PySet_Contains(PyObject *anyset, PyObject *key);
+PyAPI_FUNC(int) PySet_Discard(PyObject *set, PyObject *key);
+PyAPI_FUNC(PyObject *) PySet_Pop(PyObject *set);
+PyAPI_FUNC(Py_ssize_t) PySet_Size(PyObject *anyset);
 
 #define PyFrozenSet_CheckExact(ob) (Py_TYPE(ob) == &PyFrozenSet_Type)
 #define PyAnySet_CheckExact(ob) \
@@ -87,26 +101,6 @@ PyAPI_DATA(PyObject *) _PySet_Dummy;
     (Py_TYPE(ob) == &PyFrozenSet_Type || \
       PyType_IsSubtype(Py_TYPE(ob), &PyFrozenSet_Type))
 
-PyAPI_FUNC(PyObject *) PySet_New(PyObject *);
-PyAPI_FUNC(PyObject *) PyFrozenSet_New(PyObject *);
-PyAPI_FUNC(Py_ssize_t) PySet_Size(PyObject *anyset);
-#ifndef Py_LIMITED_API
-#define PySet_GET_SIZE(so) (((PySetObject *)(so))->used)
-#endif
-PyAPI_FUNC(int) PySet_Clear(PyObject *set);
-PyAPI_FUNC(int) PySet_Contains(PyObject *anyset, PyObject *key);
-PyAPI_FUNC(int) PySet_Discard(PyObject *set, PyObject *key);
-PyAPI_FUNC(int) PySet_Add(PyObject *set, PyObject *key);
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(int) _PySet_NextEntry(PyObject *set, Py_ssize_t *pos, PyObject **key, Py_hash_t *hash);
-#endif
-PyAPI_FUNC(PyObject *) PySet_Pop(PyObject *set);
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);
-
-PyAPI_FUNC(int) PySet_ClearFreeList(void);
-#endif
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/Include/sliceobject.h b/Include/sliceobject.h
index f7ee90c..26370e0 100644
--- a/Include/sliceobject.h
+++ b/Include/sliceobject.h
@@ -41,7 +41,7 @@ PyAPI_FUNC(int) _PySlice_GetLongIndices(PySliceObject *self, PyObject *length,
 PyAPI_FUNC(int) PySlice_GetIndices(PyObject *r, Py_ssize_t length,
                                   Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step);
 PyAPI_FUNC(int) PySlice_GetIndicesEx(PyObject *r, Py_ssize_t length,
-				    Py_ssize_t *start, Py_ssize_t *stop, 
+				    Py_ssize_t *start, Py_ssize_t *stop,
 				    Py_ssize_t *step, Py_ssize_t *slicelength);
 
 #ifdef __cplusplus
diff --git a/Include/token.h b/Include/token.h
index 905022b..2b213ee 100644
--- a/Include/token.h
+++ b/Include/token.h
@@ -58,13 +58,14 @@ extern "C" {
 #define DOUBLESTAREQUAL	46
 #define DOUBLESLASH	47
 #define DOUBLESLASHEQUAL 48
-#define AT              49	
-#define RARROW          50
-#define ELLIPSIS        51
+#define AT              49
+#define ATEQUAL		50
+#define RARROW          51
+#define ELLIPSIS        52
 /* Don't forget to update the table _PyParser_TokenNames in tokenizer.c! */
-#define OP		52
-#define ERRORTOKEN	53
-#define N_TOKENS	54
+#define OP		53
+#define ERRORTOKEN	54
+#define N_TOKENS	55
 
 /* Special definitions for cooperation with parser */
 
diff --git a/Include/typeslots.h b/Include/typeslots.h
index ad3cdfb..da2e87c 100644
--- a/Include/typeslots.h
+++ b/Include/typeslots.h
@@ -74,3 +74,5 @@
 #define Py_tp_members 72
 #define Py_tp_getset 73
 #define Py_tp_free 74
+#define Py_nb_matrix_multiply 75
+#define Py_nb_inplace_matrix_multiply 76
diff --git a/Include/ucnhash.h b/Include/ucnhash.h
index 8de9ba0..45362e9 100644
--- a/Include/ucnhash.h
+++ b/Include/ucnhash.h
@@ -16,7 +16,7 @@ typedef struct {
     int size;
 
     /* Get name for a given character code.  Returns non-zero if
-       success, zero if not.  Does not set Python exceptions. 
+       success, zero if not.  Does not set Python exceptions.
        If self is NULL, data come from the default version of the database.
        If it is not NULL, it should be a unicodedata.ucd_X_Y_Z object */
     int (*getname)(PyObject *self, Py_UCS4 code, char* buffer, int buflen,
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index d7b2ace..4ba6328 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -2060,12 +2060,6 @@ PyAPI_FUNC(int) PyUnicode_Contains(
     PyObject *element           /* Element string */
     );
 
-/* Checks whether the string contains any NUL characters. */
-
-#ifndef Py_LIMITED_API
-PyAPI_FUNC(int) _PyUnicode_HasNULChars(PyObject *);
-#endif
-
 /* Checks whether argument is a valid identifier. */
 
 PyAPI_FUNC(int) PyUnicode_IsIdentifier(PyObject *s);
@@ -2245,6 +2239,8 @@ PyAPI_FUNC(Py_UNICODE*) Py_UNICODE_strrchr(
     Py_UNICODE c
     );
 
+PyAPI_FUNC(PyObject*) _PyUnicode_FormatLong(PyObject *, int, int, int);
+
 /* Create a copy of a unicode string ending with a nul character. Return NULL
    and raise a MemoryError exception on memory allocation failure, otherwise
    return a new allocated buffer (use PyMem_Free() to free the buffer). */
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py
index 33b59ab..3d3f07b 100644
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
@@ -453,6 +453,8 @@ Mapping.register(mappingproxy)
 
 class MappingView(Sized):
 
+    __slots__ = '_mapping',
+
     def __init__(self, mapping):
         self._mapping = mapping
 
@@ -465,6 +467,8 @@ class MappingView(Sized):
 
 class KeysView(MappingView, Set):
 
+    __slots__ = ()
+
     @classmethod
     def _from_iterable(self, it):
         return set(it)
@@ -480,6 +484,8 @@ KeysView.register(dict_keys)
 
 class ItemsView(MappingView, Set):
 
+    __slots__ = ()
+
     @classmethod
     def _from_iterable(self, it):
         return set(it)
@@ -502,6 +508,8 @@ ItemsView.register(dict_items)
 
 class ValuesView(MappingView):
 
+    __slots__ = ()
+
     def __contains__(self, value):
         for key in self._mapping:
             if value == self._mapping[key]:
diff --git a/Lib/_compression.py b/Lib/_compression.py
new file mode 100644
index 0000000..b00f31b
--- /dev/null
+++ b/Lib/_compression.py
@@ -0,0 +1,152 @@
+"""Internal classes used by the gzip, lzma and bz2 modules"""
+
+import io
+
+
+BUFFER_SIZE = io.DEFAULT_BUFFER_SIZE  # Compressed data read chunk size
+
+
+class BaseStream(io.BufferedIOBase):
+    """Mode-checking helper functions."""
+
+    def _check_not_closed(self):
+        if self.closed:
+            raise ValueError("I/O operation on closed file")
+
+    def _check_can_read(self):
+        if not self.readable():
+            raise io.UnsupportedOperation("File not open for reading")
+
+    def _check_can_write(self):
+        if not self.writable():
+            raise io.UnsupportedOperation("File not open for writing")
+
+    def _check_can_seek(self):
+        if not self.readable():
+            raise io.UnsupportedOperation("Seeking is only supported "
+                                          "on files open for reading")
+        if not self.seekable():
+            raise io.UnsupportedOperation("The underlying file object "
+                                          "does not support seeking")
+
+
+class DecompressReader(io.RawIOBase):
+    """Adapts the decompressor API to a RawIOBase reader API"""
+
+    def readable(self):
+        return True
+
+    def __init__(self, fp, decomp_factory, trailing_error=(), **decomp_args):
+        self._fp = fp
+        self._eof = False
+        self._pos = 0  # Current offset in decompressed stream
+
+        # Set to size of decompressed stream once it is known, for SEEK_END
+        self._size = -1
+
+        # Save the decompressor factory and arguments.
+        # If the file contains multiple compressed streams, each
+        # stream will need a separate decompressor object. A new decompressor
+        # object is also needed when implementing a backwards seek().
+        self._decomp_factory = decomp_factory
+        self._decomp_args = decomp_args
+        self._decompressor = self._decomp_factory(**self._decomp_args)
+
+        # Exception class to catch from decompressor signifying invalid
+        # trailing data to ignore
+        self._trailing_error = trailing_error
+
+    def close(self):
+        self._decompressor = None
+        return super().close()
+
+    def seekable(self):
+        return self._fp.seekable()
+
+    def readinto(self, b):
+        with memoryview(b) as view, view.cast("B") as byte_view:
+            data = self.read(len(byte_view))
+            byte_view[:len(data)] = data
+        return len(data)
+
+    def read(self, size=-1):
+        if size < 0:
+            return self.readall()
+
+        if not size or self._eof:
+            return b""
+        data = None  # Default if EOF is encountered
+        # Depending on the input data, our call to the decompressor may not
+        # return any data. In this case, try again after reading another block.
+        while True:
+            if self._decompressor.eof:
+                rawblock = (self._decompressor.unused_data or
+                            self._fp.read(BUFFER_SIZE))
+                if not rawblock:
+                    break
+                # Continue to next stream.
+                self._decompressor = self._decomp_factory(
+                    **self._decomp_args)
+                try:
+                    data = self._decompressor.decompress(rawblock, size)
+                except self._trailing_error:
+                    # Trailing data isn't a valid compressed stream; ignore it.
+                    break
+            else:
+                if self._decompressor.needs_input:
+                    rawblock = self._fp.read(BUFFER_SIZE)
+                    if not rawblock:
+                        raise EOFError("Compressed file ended before the "
+                                       "end-of-stream marker was reached")
+                else:
+                    rawblock = b""
+                data = self._decompressor.decompress(rawblock, size)
+            if data:
+                break
+        if not data:
+            self._eof = True
+            self._size = self._pos
+            return b""
+        self._pos += len(data)
+        return data
+
+    # Rewind the file to the beginning of the data stream.
+    def _rewind(self):
+        self._fp.seek(0)
+        self._eof = False
+        self._pos = 0
+        self._decompressor = self._decomp_factory(**self._decomp_args)
+
+    def seek(self, offset, whence=io.SEEK_SET):
+        # Recalculate offset as an absolute file position.
+        if whence == io.SEEK_SET:
+            pass
+        elif whence == io.SEEK_CUR:
+            offset = self._pos + offset
+        elif whence == io.SEEK_END:
+            # Seeking relative to EOF - we need to know the file's size.
+            if self._size < 0:
+                while self.read(io.DEFAULT_BUFFER_SIZE):
+                    pass
+            offset = self._size + offset
+        else:
+            raise ValueError("Invalid value for whence: {}".format(whence))
+
+        # Make it so that offset is the number of bytes to skip forward.
+        if offset < self._pos:
+            self._rewind()
+        else:
+            offset -= self._pos
+
+        # Read and discard data until we reach the desired position.
+        while offset > 0:
+            data = self.read(min(io.DEFAULT_BUFFER_SIZE, offset))
+            if not data:
+                break
+            offset -= len(data)
+
+        return self._pos
+
+    def tell(self):
+        """Return the current file position."""
+        return self._pos
diff --git a/Lib/_dummy_thread.py b/Lib/_dummy_thread.py
index b67cfb9..36e5f38 100644
--- a/Lib/_dummy_thread.py
+++ b/Lib/_dummy_thread.py
@@ -140,6 +140,14 @@ class LockType(object):
     def locked(self):
         return self.locked_status
 
+    def __repr__(self):
+        return "<%s %s.%s object at %s>" % (
+            "locked" if self.locked_status else "unlocked",
+            self.__class__.__module__,
+            self.__class__.__qualname__,
+            hex(id(self))
+        )
+
 # Used to signal that interrupt_main was called in a "thread"
 _interrupt = False
 # True when not executing in a "thread"
diff --git a/Lib/_pydecimal.py b/Lib/_pydecimal.py
new file mode 100644
index 0000000..05ba4ee
--- /dev/null
+++ b/Lib/_pydecimal.py
@@ -0,0 +1,6380 @@
+# Copyright (c) 2004 Python Software Foundation.
+# All rights reserved.
+
+# Written by Eric Price <eprice at tjhsst.edu>
+#    and Facundo Batista <facundo at taniquetil.com.ar>
+#    and Raymond Hettinger <python at rcn.com>
+#    and Aahz <aahz at pobox.com>
+#    and Tim Peters
+
+# This module should be kept in sync with the latest updates of the
+# IBM specification as it evolves.  Those updates will be treated
+# as bug fixes (deviation from the spec is a compatibility, usability
+# bug) and will be backported.  At this point the spec is stabilizing
+# and the updates are becoming fewer, smaller, and less significant.
+
+"""
+This is an implementation of decimal floating point arithmetic based on
+the General Decimal Arithmetic Specification:
+
+    http://speleotrove.com/decimal/decarith.html
+
+and IEEE standard 854-1987:
+
+    http://en.wikipedia.org/wiki/IEEE_854-1987
+
+Decimal floating point has finite precision with arbitrarily large bounds.
+
+The purpose of this module is to support arithmetic using familiar
+"schoolhouse" rules and to avoid some of the tricky representation
+issues associated with binary floating point.  The package is especially
+useful for financial applications or for contexts where users have
+expectations that are at odds with binary floating point (for instance,
+in binary floating point, 1.00 % 0.1 gives 0.09999999999999995 instead
+of 0.0; Decimal('1.00') % Decimal('0.1') returns the expected
+Decimal('0.00')).
+
+Here are some examples of using the decimal module:
+
+>>> from decimal import *
+>>> setcontext(ExtendedContext)
+>>> Decimal(0)
+Decimal('0')
+>>> Decimal('1')
+Decimal('1')
+>>> Decimal('-.0123')
+Decimal('-0.0123')
+>>> Decimal(123456)
+Decimal('123456')
+>>> Decimal('123.45e12345678')
+Decimal('1.2345E+12345680')
+>>> Decimal('1.33') + Decimal('1.27')
+Decimal('2.60')
+>>> Decimal('12.34') + Decimal('3.87') - Decimal('18.41')
+Decimal('-2.20')
+>>> dig = Decimal(1)
+>>> print(dig / Decimal(3))
+0.333333333
+>>> getcontext().prec = 18
+>>> print(dig / Decimal(3))
+0.333333333333333333
+>>> print(dig.sqrt())
+1
+>>> print(Decimal(3).sqrt())
+1.73205080756887729
+>>> print(Decimal(3) ** 123)
+4.85192780976896427E+58
+>>> inf = Decimal(1) / Decimal(0)
+>>> print(inf)
+Infinity
+>>> neginf = Decimal(-1) / Decimal(0)
+>>> print(neginf)
+-Infinity
+>>> print(neginf + inf)
+NaN
+>>> print(neginf * inf)
+-Infinity
+>>> print(dig / 0)
+Infinity
+>>> getcontext().traps[DivisionByZero] = 1
+>>> print(dig / 0)
+Traceback (most recent call last):
+  ...
+  ...
+  ...
+decimal.DivisionByZero: x / 0
+>>> c = Context()
+>>> c.traps[InvalidOperation] = 0
+>>> print(c.flags[InvalidOperation])
+0
+>>> c.divide(Decimal(0), Decimal(0))
+Decimal('NaN')
+>>> c.traps[InvalidOperation] = 1
+>>> print(c.flags[InvalidOperation])
+1
+>>> c.flags[InvalidOperation] = 0
+>>> print(c.flags[InvalidOperation])
+0
+>>> print(c.divide(Decimal(0), Decimal(0)))
+Traceback (most recent call last):
+  ...
+  ...
+  ...
+decimal.InvalidOperation: 0 / 0
+>>> print(c.flags[InvalidOperation])
+1
+>>> c.flags[InvalidOperation] = 0
+>>> c.traps[InvalidOperation] = 0
+>>> print(c.divide(Decimal(0), Decimal(0)))
+NaN
+>>> print(c.flags[InvalidOperation])
+1
+>>>
+"""
+
+__all__ = [
+    # Two major classes
+    'Decimal', 'Context',
+
+    # Named tuple representation
+    'DecimalTuple',
+
+    # Contexts
+    'DefaultContext', 'BasicContext', 'ExtendedContext',
+
+    # Exceptions
+    'DecimalException', 'Clamped', 'InvalidOperation', 'DivisionByZero',
+    'Inexact', 'Rounded', 'Subnormal', 'Overflow', 'Underflow',
+    'FloatOperation',
+
+    # Exceptional conditions that trigger InvalidOperation
+    'DivisionImpossible', 'InvalidContext', 'ConversionSyntax', 'DivisionUndefined',
+
+    # Constants for use in setting up contexts
+    'ROUND_DOWN', 'ROUND_HALF_UP', 'ROUND_HALF_EVEN', 'ROUND_CEILING',
+    'ROUND_FLOOR', 'ROUND_UP', 'ROUND_HALF_DOWN', 'ROUND_05UP',
+
+    # Functions for manipulating contexts
+    'setcontext', 'getcontext', 'localcontext',
+
+    # Limits for the C version for compatibility
+    'MAX_PREC',  'MAX_EMAX', 'MIN_EMIN', 'MIN_ETINY',
+
+    # C version: compile time choice that enables the thread local context
+    'HAVE_THREADS'
+]
+
+__xname__ = __name__    # sys.modules lookup (--without-threads)
+__name__ = 'decimal'    # For pickling
+__version__ = '1.70'    # Highest version of the spec this complies with
+                        # See http://speleotrove.com/decimal/
+__libmpdec_version__ = "2.4.1" # compatible libmpdec version
+
+import math as _math
+import numbers as _numbers
+import sys
+
+try:
+    from collections import namedtuple as _namedtuple
+    DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent')
+except ImportError:
+    DecimalTuple = lambda *args: args
+
+# Rounding
+ROUND_DOWN = 'ROUND_DOWN'
+ROUND_HALF_UP = 'ROUND_HALF_UP'
+ROUND_HALF_EVEN = 'ROUND_HALF_EVEN'
+ROUND_CEILING = 'ROUND_CEILING'
+ROUND_FLOOR = 'ROUND_FLOOR'
+ROUND_UP = 'ROUND_UP'
+ROUND_HALF_DOWN = 'ROUND_HALF_DOWN'
+ROUND_05UP = 'ROUND_05UP'
+
+# Compatibility with the C version
+HAVE_THREADS = True
+if sys.maxsize == 2**63-1:
+    MAX_PREC = 999999999999999999
+    MAX_EMAX = 999999999999999999
+    MIN_EMIN = -999999999999999999
+else:
+    MAX_PREC = 425000000
+    MAX_EMAX = 425000000
+    MIN_EMIN = -425000000
+
+MIN_ETINY = MIN_EMIN - (MAX_PREC-1)
+
+# Errors
+
+class DecimalException(ArithmeticError):
+    """Base exception class.
+
+    Used exceptions derive from this.
+    If an exception derives from another exception besides this (such as
+    Underflow (Inexact, Rounded, Subnormal) that indicates that it is only
+    called if the others are present.  This isn't actually used for
+    anything, though.
+
+    handle  -- Called when context._raise_error is called and the
+               trap_enabler is not set.  First argument is self, second is the
+               context.  More arguments can be given, those being after
+               the explanation in _raise_error (For example,
+               context._raise_error(NewError, '(-x)!', self._sign) would
+               call NewError().handle(context, self._sign).)
+
+    To define a new exception, it should be sufficient to have it derive
+    from DecimalException.
+    """
+    def handle(self, context, *args):
+        pass
+
+
+class Clamped(DecimalException):
+    """Exponent of a 0 changed to fit bounds.
+
+    This occurs and signals clamped if the exponent of a result has been
+    altered in order to fit the constraints of a specific concrete
+    representation.  This may occur when the exponent of a zero result would
+    be outside the bounds of a representation, or when a large normal
+    number would have an encoded exponent that cannot be represented.  In
+    this latter case, the exponent is reduced to fit and the corresponding
+    number of zero digits are appended to the coefficient ("fold-down").
+    """
+
+class InvalidOperation(DecimalException):
+    """An invalid operation was performed.
+
+    Various bad things cause this:
+
+    Something creates a signaling NaN
+    -INF + INF
+    0 * (+-)INF
+    (+-)INF / (+-)INF
+    x % 0
+    (+-)INF % x
+    x._rescale( non-integer )
+    sqrt(-x) , x > 0
+    0 ** 0
+    x ** (non-integer)
+    x ** (+-)INF
+    An operand is invalid
+
+    The result of the operation after these is a quiet positive NaN,
+    except when the cause is a signaling NaN, in which case the result is
+    also a quiet NaN, but with the original sign, and an optional
+    diagnostic information.
+    """
+    def handle(self, context, *args):
+        if args:
+            ans = _dec_from_triple(args[0]._sign, args[0]._int, 'n', True)
+            return ans._fix_nan(context)
+        return _NaN
+
+class ConversionSyntax(InvalidOperation):
+    """Trying to convert badly formed string.
+
+    This occurs and signals invalid-operation if an string is being
+    converted to a number and it does not conform to the numeric string
+    syntax.  The result is [0,qNaN].
+    """
+    def handle(self, context, *args):
+        return _NaN
+
+class DivisionByZero(DecimalException, ZeroDivisionError):
+    """Division by 0.
+
+    This occurs and signals division-by-zero if division of a finite number
+    by zero was attempted (during a divide-integer or divide operation, or a
+    power operation with negative right-hand operand), and the dividend was
+    not zero.
+
+    The result of the operation is [sign,inf], where sign is the exclusive
+    or of the signs of the operands for divide, or is 1 for an odd power of
+    -0, for power.
+    """
+
+    def handle(self, context, sign, *args):
+        return _SignedInfinity[sign]
+
+class DivisionImpossible(InvalidOperation):
+    """Cannot perform the division adequately.
+
+    This occurs and signals invalid-operation if the integer result of a
+    divide-integer or remainder operation had too many digits (would be
+    longer than precision).  The result is [0,qNaN].
+    """
+
+    def handle(self, context, *args):
+        return _NaN
+
+class DivisionUndefined(InvalidOperation, ZeroDivisionError):
+    """Undefined result of division.
+
+    This occurs and signals invalid-operation if division by zero was
+    attempted (during a divide-integer, divide, or remainder operation), and
+    the dividend is also zero.  The result is [0,qNaN].
+    """
+
+    def handle(self, context, *args):
+        return _NaN
+
+class Inexact(DecimalException):
+    """Had to round, losing information.
+
+    This occurs and signals inexact whenever the result of an operation is
+    not exact (that is, it needed to be rounded and any discarded digits
+    were non-zero), or if an overflow or underflow condition occurs.  The
+    result in all cases is unchanged.
+
+    The inexact signal may be tested (or trapped) to determine if a given
+    operation (or sequence of operations) was inexact.
+    """
+
+class InvalidContext(InvalidOperation):
+    """Invalid context.  Unknown rounding, for example.
+
+    This occurs and signals invalid-operation if an invalid context was
+    detected during an operation.  This can occur if contexts are not checked
+    on creation and either the precision exceeds the capability of the
+    underlying concrete representation or an unknown or unsupported rounding
+    was specified.  These aspects of the context need only be checked when
+    the values are required to be used.  The result is [0,qNaN].
+    """
+
+    def handle(self, context, *args):
+        return _NaN
+
+class Rounded(DecimalException):
+    """Number got rounded (not  necessarily changed during rounding).
+
+    This occurs and signals rounded whenever the result of an operation is
+    rounded (that is, some zero or non-zero digits were discarded from the
+    coefficient), or if an overflow or underflow condition occurs.  The
+    result in all cases is unchanged.
+
+    The rounded signal may be tested (or trapped) to determine if a given
+    operation (or sequence of operations) caused a loss of precision.
+    """
+
+class Subnormal(DecimalException):
+    """Exponent < Emin before rounding.
+
+    This occurs and signals subnormal whenever the result of a conversion or
+    operation is subnormal (that is, its adjusted exponent is less than
+    Emin, before any rounding).  The result in all cases is unchanged.
+
+    The subnormal signal may be tested (or trapped) to determine if a given
+    or operation (or sequence of operations) yielded a subnormal result.
+    """
+
+class Overflow(Inexact, Rounded):
+    """Numerical overflow.
+
+    This occurs and signals overflow if the adjusted exponent of a result
+    (from a conversion or from an operation that is not an attempt to divide
+    by zero), after rounding, would be greater than the largest value that
+    can be handled by the implementation (the value Emax).
+
+    The result depends on the rounding mode:
+
+    For round-half-up and round-half-even (and for round-half-down and
+    round-up, if implemented), the result of the operation is [sign,inf],
+    where sign is the sign of the intermediate result.  For round-down, the
+    result is the largest finite number that can be represented in the
+    current precision, with the sign of the intermediate result.  For
+    round-ceiling, the result is the same as for round-down if the sign of
+    the intermediate result is 1, or is [0,inf] otherwise.  For round-floor,
+    the result is the same as for round-down if the sign of the intermediate
+    result is 0, or is [1,inf] otherwise.  In all cases, Inexact and Rounded
+    will also be raised.
+    """
+
+    def handle(self, context, sign, *args):
+        if context.rounding in (ROUND_HALF_UP, ROUND_HALF_EVEN,
+                                ROUND_HALF_DOWN, ROUND_UP):
+            return _SignedInfinity[sign]
+        if sign == 0:
+            if context.rounding == ROUND_CEILING:
+                return _SignedInfinity[sign]
+            return _dec_from_triple(sign, '9'*context.prec,
+                            context.Emax-context.prec+1)
+        if sign == 1:
+            if context.rounding == ROUND_FLOOR:
+                return _SignedInfinity[sign]
+            return _dec_from_triple(sign, '9'*context.prec,
+                             context.Emax-context.prec+1)
+
+
+class Underflow(Inexact, Rounded, Subnormal):
+    """Numerical underflow with result rounded to 0.
+
+    This occurs and signals underflow if a result is inexact and the
+    adjusted exponent of the result would be smaller (more negative) than
+    the smallest value that can be handled by the implementation (the value
+    Emin).  That is, the result is both inexact and subnormal.
+
+    The result after an underflow will be a subnormal number rounded, if
+    necessary, so that its exponent is not less than Etiny.  This may result
+    in 0 with the sign of the intermediate result and an exponent of Etiny.
+
+    In all cases, Inexact, Rounded, and Subnormal will also be raised.
+    """
+
+class FloatOperation(DecimalException, TypeError):
+    """Enable stricter semantics for mixing floats and Decimals.
+
+    If the signal is not trapped (default), mixing floats and Decimals is
+    permitted in the Decimal() constructor, context.create_decimal() and
+    all comparison operators. Both conversion and comparisons are exact.
+    Any occurrence of a mixed operation is silently recorded by setting
+    FloatOperation in the context flags.  Explicit conversions with
+    Decimal.from_float() or context.create_decimal_from_float() do not
+    set the flag.
+
+    Otherwise (the signal is trapped), only equality comparisons and explicit
+    conversions are silent. All other mixed operations raise FloatOperation.
+    """
+
+# List of public traps and flags
+_signals = [Clamped, DivisionByZero, Inexact, Overflow, Rounded,
+            Underflow, InvalidOperation, Subnormal, FloatOperation]
+
+# Map conditions (per the spec) to signals
+_condition_map = {ConversionSyntax:InvalidOperation,
+                  DivisionImpossible:InvalidOperation,
+                  DivisionUndefined:InvalidOperation,
+                  InvalidContext:InvalidOperation}
+
+# Valid rounding modes
+_rounding_modes = (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_CEILING,
+                   ROUND_FLOOR, ROUND_UP, ROUND_HALF_DOWN, ROUND_05UP)
+
+##### Context Functions ##################################################
+
+# The getcontext() and setcontext() function manage access to a thread-local
+# current context.  Py2.4 offers direct support for thread locals.  If that
+# is not available, use threading.current_thread() which is slower but will
+# work for older Pythons.  If threads are not part of the build, create a
+# mock threading object with threading.local() returning the module namespace.
+
+try:
+    import threading
+except ImportError:
+    # Python was compiled without threads; create a mock object instead
+    class MockThreading(object):
+        def local(self, sys=sys):
+            return sys.modules[__xname__]
+    threading = MockThreading()
+    del MockThreading
+
+try:
+    threading.local
+
+except AttributeError:
+
+    # To fix reloading, force it to create a new context
+    # Old contexts have different exceptions in their dicts, making problems.
+    if hasattr(threading.current_thread(), '__decimal_context__'):
+        del threading.current_thread().__decimal_context__
+
+    def setcontext(context):
+        """Set this thread's context to context."""
+        if context in (DefaultContext, BasicContext, ExtendedContext):
+            context = context.copy()
+            context.clear_flags()
+        threading.current_thread().__decimal_context__ = context
+
+    def getcontext():
+        """Returns this thread's context.
+
+        If this thread does not yet have a context, returns
+        a new context and sets this thread's context.
+        New contexts are copies of DefaultContext.
+        """
+        try:
+            return threading.current_thread().__decimal_context__
+        except AttributeError:
+            context = Context()
+            threading.current_thread().__decimal_context__ = context
+            return context
+
+else:
+
+    local = threading.local()
+    if hasattr(local, '__decimal_context__'):
+        del local.__decimal_context__
+
+    def getcontext(_local=local):
+        """Returns this thread's context.
+
+        If this thread does not yet have a context, returns
+        a new context and sets this thread's context.
+        New contexts are copies of DefaultContext.
+        """
+        try:
+            return _local.__decimal_context__
+        except AttributeError:
+            context = Context()
+            _local.__decimal_context__ = context
+            return context
+
+    def setcontext(context, _local=local):
+        """Set this thread's context to context."""
+        if context in (DefaultContext, BasicContext, ExtendedContext):
+            context = context.copy()
+            context.clear_flags()
+        _local.__decimal_context__ = context
+
+    del threading, local        # Don't contaminate the namespace
+
+def localcontext(ctx=None):
+    """Return a context manager for a copy of the supplied context
+
+    Uses a copy of the current context if no context is specified
+    The returned context manager creates a local decimal context
+    in a with statement:
+        def sin(x):
+             with localcontext() as ctx:
+                 ctx.prec += 2
+                 # Rest of sin calculation algorithm
+                 # uses a precision 2 greater than normal
+             return +s  # Convert result to normal precision
+
+         def sin(x):
+             with localcontext(ExtendedContext):
+                 # Rest of sin calculation algorithm
+                 # uses the Extended Context from the
+                 # General Decimal Arithmetic Specification
+             return +s  # Convert result to normal context
+
+    >>> setcontext(DefaultContext)
+    >>> print(getcontext().prec)
+    28
+    >>> with localcontext():
+    ...     ctx = getcontext()
+    ...     ctx.prec += 2
+    ...     print(ctx.prec)
+    ...
+    30
+    >>> with localcontext(ExtendedContext):
+    ...     print(getcontext().prec)
+    ...
+    9
+    >>> print(getcontext().prec)
+    28
+    """
+    if ctx is None: ctx = getcontext()
+    return _ContextManager(ctx)
+
+
+##### Decimal class #######################################################
+
+# Do not subclass Decimal from numbers.Real and do not register it as such
+# (because Decimals are not interoperable with floats).  See the notes in
+# numbers.py for more detail.
+
+class Decimal(object):
+    """Floating point class for decimal arithmetic."""
+
+    __slots__ = ('_exp','_int','_sign', '_is_special')
+    # Generally, the value of the Decimal instance is given by
+    #  (-1)**_sign * _int * 10**_exp
+    # Special values are signified by _is_special == True
+
+    # We're immutable, so use __new__ not __init__
+    def __new__(cls, value="0", context=None):
+        """Create a decimal point instance.
+
+        >>> Decimal('3.14')              # string input
+        Decimal('3.14')
+        >>> Decimal((0, (3, 1, 4), -2))  # tuple (sign, digit_tuple, exponent)
+        Decimal('3.14')
+        >>> Decimal(314)                 # int
+        Decimal('314')
+        >>> Decimal(Decimal(314))        # another decimal instance
+        Decimal('314')
+        >>> Decimal('  3.14  \\n')        # leading and trailing whitespace okay
+        Decimal('3.14')
+        """
+
+        # Note that the coefficient, self._int, is actually stored as
+        # a string rather than as a tuple of digits.  This speeds up
+        # the "digits to integer" and "integer to digits" conversions
+        # that are used in almost every arithmetic operation on
+        # Decimals.  This is an internal detail: the as_tuple function
+        # and the Decimal constructor still deal with tuples of
+        # digits.
+
+        self = object.__new__(cls)
+
+        # From a string
+        # REs insist on real strings, so we can too.
+        if isinstance(value, str):
+            m = _parser(value.strip())
+            if m is None:
+                if context is None:
+                    context = getcontext()
+                return context._raise_error(ConversionSyntax,
+                                "Invalid literal for Decimal: %r" % value)
+
+            if m.group('sign') == "-":
+                self._sign = 1
+            else:
+                self._sign = 0
+            intpart = m.group('int')
+            if intpart is not None:
+                # finite number
+                fracpart = m.group('frac') or ''
+                exp = int(m.group('exp') or '0')
+                self._int = str(int(intpart+fracpart))
+                self._exp = exp - len(fracpart)
+                self._is_special = False
+            else:
+                diag = m.group('diag')
+                if diag is not None:
+                    # NaN
+                    self._int = str(int(diag or '0')).lstrip('0')
+                    if m.group('signal'):
+                        self._exp = 'N'
+                    else:
+                        self._exp = 'n'
+                else:
+                    # infinity
+                    self._int = '0'
+                    self._exp = 'F'
+                self._is_special = True
+            return self
+
+        # From an integer
+        if isinstance(value, int):
+            if value >= 0:
+                self._sign = 0
+            else:
+                self._sign = 1
+            self._exp = 0
+            self._int = str(abs(value))
+            self._is_special = False
+            return self
+
+        # From another decimal
+        if isinstance(value, Decimal):
+            self._exp  = value._exp
+            self._sign = value._sign
+            self._int  = value._int
+            self._is_special  = value._is_special
+            return self
+
+        # From an internal working value
+        if isinstance(value, _WorkRep):
+            self._sign = value.sign
+            self._int = str(value.int)
+            self._exp = int(value.exp)
+            self._is_special = False
+            return self
+
+        # tuple/list conversion (possibly from as_tuple())
+        if isinstance(value, (list,tuple)):
+            if len(value) != 3:
+                raise ValueError('Invalid tuple size in creation of Decimal '
+                                 'from list or tuple.  The list or tuple '
+                                 'should have exactly three elements.')
+            # process sign.  The isinstance test rejects floats
+            if not (isinstance(value[0], int) and value[0] in (0,1)):
+                raise ValueError("Invalid sign.  The first value in the tuple "
+                                 "should be an integer; either 0 for a "
+                                 "positive number or 1 for a negative number.")
+            self._sign = value[0]
+            if value[2] == 'F':
+                # infinity: value[1] is ignored
+                self._int = '0'
+                self._exp = value[2]
+                self._is_special = True
+            else:
+                # process and validate the digits in value[1]
+                digits = []
+                for digit in value[1]:
+                    if isinstance(digit, int) and 0 <= digit <= 9:
+                        # skip leading zeros
+                        if digits or digit != 0:
+                            digits.append(digit)
+                    else:
+                        raise ValueError("The second value in the tuple must "
+                                         "be composed of integers in the range "
+                                         "0 through 9.")
+                if value[2] in ('n', 'N'):
+                    # NaN: digits form the diagnostic
+                    self._int = ''.join(map(str, digits))
+                    self._exp = value[2]
+                    self._is_special = True
+                elif isinstance(value[2], int):
+                    # finite number: digits give the coefficient
+                    self._int = ''.join(map(str, digits or [0]))
+                    self._exp = value[2]
+                    self._is_special = False
+                else:
+                    raise ValueError("The third value in the tuple must "
+                                     "be an integer, or one of the "
+                                     "strings 'F', 'n', 'N'.")
+            return self
+
+        if isinstance(value, float):
+            if context is None:
+                context = getcontext()
+            context._raise_error(FloatOperation,
+                "strict semantics for mixing floats and Decimals are "
+                "enabled")
+            value = Decimal.from_float(value)
+            self._exp  = value._exp
+            self._sign = value._sign
+            self._int  = value._int
+            self._is_special  = value._is_special
+            return self
+
+        raise TypeError("Cannot convert %r to Decimal" % value)
+
+    @classmethod
+    def from_float(cls, f):
+        """Converts a float to a decimal number, exactly.
+
+        Note that Decimal.from_float(0.1) is not the same as Decimal('0.1').
+        Since 0.1 is not exactly representable in binary floating point, the
+        value is stored as the nearest representable value which is
+        0x1.999999999999ap-4.  The exact equivalent of the value in decimal
+        is 0.1000000000000000055511151231257827021181583404541015625.
+
+        >>> Decimal.from_float(0.1)
+        Decimal('0.1000000000000000055511151231257827021181583404541015625')
+        >>> Decimal.from_float(float('nan'))
+        Decimal('NaN')
+        >>> Decimal.from_float(float('inf'))
+        Decimal('Infinity')
+        >>> Decimal.from_float(-float('inf'))
+        Decimal('-Infinity')
+        >>> Decimal.from_float(-0.0)
+        Decimal('-0')
+
+        """
+        if isinstance(f, int):                # handle integer inputs
+            return cls(f)
+        if not isinstance(f, float):
+            raise TypeError("argument must be int or float.")
+        if _math.isinf(f) or _math.isnan(f):
+            return cls(repr(f))
+        if _math.copysign(1.0, f) == 1.0:
+            sign = 0
+        else:
+            sign = 1
+        n, d = abs(f).as_integer_ratio()
+        k = d.bit_length() - 1
+        result = _dec_from_triple(sign, str(n*5**k), -k)
+        if cls is Decimal:
+            return result
+        else:
+            return cls(result)
+
+    def _isnan(self):
+        """Returns whether the number is not actually one.
+
+        0 if a number
+        1 if NaN
+        2 if sNaN
+        """
+        if self._is_special:
+            exp = self._exp
+            if exp == 'n':
+                return 1
+            elif exp == 'N':
+                return 2
+        return 0
+
+    def _isinfinity(self):
+        """Returns whether the number is infinite
+
+        0 if finite or not a number
+        1 if +INF
+        -1 if -INF
+        """
+        if self._exp == 'F':
+            if self._sign:
+                return -1
+            return 1
+        return 0
+
+    def _check_nans(self, other=None, context=None):
+        """Returns whether the number is not actually one.
+
+        if self, other are sNaN, signal
+        if self, other are NaN return nan
+        return 0
+
+        Done before operations.
+        """
+
+        self_is_nan = self._isnan()
+        if other is None:
+            other_is_nan = False
+        else:
+            other_is_nan = other._isnan()
+
+        if self_is_nan or other_is_nan:
+            if context is None:
+                context = getcontext()
+
+            if self_is_nan == 2:
+                return context._raise_error(InvalidOperation, 'sNaN',
+                                        self)
+            if other_is_nan == 2:
+                return context._raise_error(InvalidOperation, 'sNaN',
+                                        other)
+            if self_is_nan:
+                return self._fix_nan(context)
+
+            return other._fix_nan(context)
+        return 0
+
+    def _compare_check_nans(self, other, context):
+        """Version of _check_nans used for the signaling comparisons
+        compare_signal, __le__, __lt__, __ge__, __gt__.
+
+        Signal InvalidOperation if either self or other is a (quiet
+        or signaling) NaN.  Signaling NaNs take precedence over quiet
+        NaNs.
+
+        Return 0 if neither operand is a NaN.
+
+        """
+        if context is None:
+            context = getcontext()
+
+        if self._is_special or other._is_special:
+            if self.is_snan():
+                return context._raise_error(InvalidOperation,
+                                            'comparison involving sNaN',
+                                            self)
+            elif other.is_snan():
+                return context._raise_error(InvalidOperation,
+                                            'comparison involving sNaN',
+                                            other)
+            elif self.is_qnan():
+                return context._raise_error(InvalidOperation,
+                                            'comparison involving NaN',
+                                            self)
+            elif other.is_qnan():
+                return context._raise_error(InvalidOperation,
+                                            'comparison involving NaN',
+                                            other)
+        return 0
+
+    def __bool__(self):
+        """Return True if self is nonzero; otherwise return False.
+
+        NaNs and infinities are considered nonzero.
+        """
+        return self._is_special or self._int != '0'
+
+    def _cmp(self, other):
+        """Compare the two non-NaN decimal instances self and other.
+
+        Returns -1 if self < other, 0 if self == other and 1
+        if self > other.  This routine is for internal use only."""
+
+        if self._is_special or other._is_special:
+            self_inf = self._isinfinity()
+            other_inf = other._isinfinity()
+            if self_inf == other_inf:
+                return 0
+            elif self_inf < other_inf:
+                return -1
+            else:
+                return 1
+
+        # check for zeros;  Decimal('0') == Decimal('-0')
+        if not self:
+            if not other:
+                return 0
+            else:
+                return -((-1)**other._sign)
+        if not other:
+            return (-1)**self._sign
+
+        # If different signs, neg one is less
+        if other._sign < self._sign:
+            return -1
+        if self._sign < other._sign:
+            return 1
+
+        self_adjusted = self.adjusted()
+        other_adjusted = other.adjusted()
+        if self_adjusted == other_adjusted:
+            self_padded = self._int + '0'*(self._exp - other._exp)
+            other_padded = other._int + '0'*(other._exp - self._exp)
+            if self_padded == other_padded:
+                return 0
+            elif self_padded < other_padded:
+                return -(-1)**self._sign
+            else:
+                return (-1)**self._sign
+        elif self_adjusted > other_adjusted:
+            return (-1)**self._sign
+        else: # self_adjusted < other_adjusted
+            return -((-1)**self._sign)
+
+    # Note: The Decimal standard doesn't cover rich comparisons for
+    # Decimals.  In particular, the specification is silent on the
+    # subject of what should happen for a comparison involving a NaN.
+    # We take the following approach:
+    #
+    #   == comparisons involving a quiet NaN always return False
+    #   != comparisons involving a quiet NaN always return True
+    #   == or != comparisons involving a signaling NaN signal
+    #      InvalidOperation, and return False or True as above if the
+    #      InvalidOperation is not trapped.
+    #   <, >, <= and >= comparisons involving a (quiet or signaling)
+    #      NaN signal InvalidOperation, and return False if the
+    #      InvalidOperation is not trapped.
+    #
+    # This behavior is designed to conform as closely as possible to
+    # that specified by IEEE 754.
+
+    def __eq__(self, other, context=None):
+        self, other = _convert_for_comparison(self, other, equality_op=True)
+        if other is NotImplemented:
+            return other
+        if self._check_nans(other, context):
+            return False
+        return self._cmp(other) == 0
+
+    def __lt__(self, other, context=None):
+        self, other = _convert_for_comparison(self, other)
+        if other is NotImplemented:
+            return other
+        ans = self._compare_check_nans(other, context)
+        if ans:
+            return False
+        return self._cmp(other) < 0
+
+    def __le__(self, other, context=None):
+        self, other = _convert_for_comparison(self, other)
+        if other is NotImplemented:
+            return other
+        ans = self._compare_check_nans(other, context)
+        if ans:
+            return False
+        return self._cmp(other) <= 0
+
+    def __gt__(self, other, context=None):
+        self, other = _convert_for_comparison(self, other)
+        if other is NotImplemented:
+            return other
+        ans = self._compare_check_nans(other, context)
+        if ans:
+            return False
+        return self._cmp(other) > 0
+
+    def __ge__(self, other, context=None):
+        self, other = _convert_for_comparison(self, other)
+        if other is NotImplemented:
+            return other
+        ans = self._compare_check_nans(other, context)
+        if ans:
+            return False
+        return self._cmp(other) >= 0
+
+    def compare(self, other, context=None):
+        """Compare self to other.  Return a decimal value:
+
+        a or b is a NaN ==> Decimal('NaN')
+        a < b           ==> Decimal('-1')
+        a == b          ==> Decimal('0')
+        a > b           ==> Decimal('1')
+        """
+        other = _convert_other(other, raiseit=True)
+
+        # Compare(NaN, NaN) = NaN
+        if (self._is_special or other and other._is_special):
+            ans = self._check_nans(other, context)
+            if ans:
+                return ans
+
+        return Decimal(self._cmp(other))
+
+    def __hash__(self):
+        """x.__hash__() <==> hash(x)"""
+
+        # In order to make sure that the hash of a Decimal instance
+        # agrees with the hash of a numerically equal integer, float
+        # or Fraction, we follow the rules for numeric hashes outlined
+        # in the documentation.  (See library docs, 'Built-in Types').
+        if self._is_special:
+            if self.is_snan():
+                raise TypeError('Cannot hash a signaling NaN value.')
+            elif self.is_nan():
+                return _PyHASH_NAN
+            else:
+                if self._sign:
+                    return -_PyHASH_INF
+                else:
+                    return _PyHASH_INF
+
+        if self._exp >= 0:
+            exp_hash = pow(10, self._exp, _PyHASH_MODULUS)
+        else:
+            exp_hash = pow(_PyHASH_10INV, -self._exp, _PyHASH_MODULUS)
+        hash_ = int(self._int) * exp_hash % _PyHASH_MODULUS
+        ans = hash_ if self >= 0 else -hash_
+        return -2 if ans == -1 else ans
+
+    def as_tuple(self):
+        """Represents the number as a triple tuple.
+
+        To show the internals exactly as they are.
+        """
+        return DecimalTuple(self._sign, tuple(map(int, self._int)), self._exp)
+
+    def __repr__(self):
+        """Represents the number as an instance of Decimal."""
+        # Invariant:  eval(repr(d)) == d
+        return "Decimal('%s')" % str(self)
+
+    def __str__(self, eng=False, context=None):
+        """Return string representation of the number in scientific notation.
+
+        Captures all of the information in the underlying representation.
+        """
+
+        sign = ['', '-'][self._sign]
+        if self._is_special:
+            if self._exp == 'F':
+                return sign + 'Infinity'
+            elif self._exp == 'n':
+                return sign + 'NaN' + self._int
+            else: # self._exp == 'N'
+                return sign + 'sNaN' + self._int
+
+        # number of digits of self._int to left of decimal point
+        leftdigits = self._exp + len(self._int)
+
+        # dotplace is number of digits of self._int to the left of the
+        # decimal point in the mantissa of the output string (that is,
+        # after adjusting the exponent)
+        if self._exp <= 0 and leftdigits > -6:
+            # no exponent required
+            dotplace = leftdigits
+        elif not eng:
+            # usual scientific notation: 1 digit on left of the point
+            dotplace = 1
+        elif self._int == '0':
+            # engineering notation, zero
+            dotplace = (leftdigits + 1) % 3 - 1
+        else:
+            # engineering notation, nonzero
+            dotplace = (leftdigits - 1) % 3 + 1
+
+        if dotplace <= 0:
+            intpart = '0'
+            fracpart = '.' + '0'*(-dotplace) + self._int
+        elif dotplace >= len(self._int):
+            intpart = self._int+'0'*(dotplace-len(self._int))
+            fracpart = ''
+        else:
+            intpart = self._int[:dotplace]
+            fracpart = '.' + self._int[dotplace:]
+        if leftdigits == dotplace:
+            exp = ''
+        else:
+            if context is None:
+                context = getcontext()
+            exp = ['e', 'E'][context.capitals] + "%+d" % (leftdigits-dotplace)
+
+        return sign + intpart + fracpart + exp
+
+    def to_eng_string(self, context=None):
+        """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.
+
+        Same rules for when in exponential and when as a value as in __str__.
+        """
+        return self.__str__(eng=True, context=context)
+
+    def __neg__(self, context=None):
+        """Returns a copy with the sign switched.
+
+        Rounds, if it has reason.
+        """
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+
+        if context is None:
+            context = getcontext()
+
+        if not self and context.rounding != ROUND_FLOOR:
+            # -Decimal('0') is Decimal('0'), not Decimal('-0'), except
+            # in ROUND_FLOOR rounding mode.
+            ans = self.copy_abs()
+        else:
+            ans = self.copy_negate()
+
+        return ans._fix(context)
+
+    def __pos__(self, context=None):
+        """Returns a copy, unless it is a sNaN.
+
+        Rounds the number (if more then precision digits)
+        """
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+
+        if context is None:
+            context = getcontext()
+
+        if not self and context.rounding != ROUND_FLOOR:
+            # + (-0) = 0, except in ROUND_FLOOR rounding mode.
+            ans = self.copy_abs()
+        else:
+            ans = Decimal(self)
+
+        return ans._fix(context)
+
+    def __abs__(self, round=True, context=None):
+        """Returns the absolute value of self.
+
+        If the keyword argument 'round' is false, do not round.  The
+        expression self.__abs__(round=False) is equivalent to
+        self.copy_abs().
+        """
+        if not round:
+            return self.copy_abs()
+
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+
+        if self._sign:
+            ans = self.__neg__(context=context)
+        else:
+            ans = self.__pos__(context=context)
+
+        return ans
+
+    def __add__(self, other, context=None):
+        """Returns self + other.
+
+        -INF + INF (or the reverse) cause InvalidOperation errors.
+        """
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if context is None:
+            context = getcontext()
+
+        if self._is_special or other._is_special:
+            ans = self._check_nans(other, context)
+            if ans:
+                return ans
+
+            if self._isinfinity():
+                # If both INF, same sign => same as both, opposite => error.
+                if self._sign != other._sign and other._isinfinity():
+                    return context._raise_error(InvalidOperation, '-INF + INF')
+                return Decimal(self)
+            if other._isinfinity():
+                return Decimal(other)  # Can't both be infinity here
+
+        exp = min(self._exp, other._exp)
+        negativezero = 0
+        if context.rounding == ROUND_FLOOR and self._sign != other._sign:
+            # If the answer is 0, the sign should be negative, in this case.
+            negativezero = 1
+
+        if not self and not other:
+            sign = min(self._sign, other._sign)
+            if negativezero:
+                sign = 1
+            ans = _dec_from_triple(sign, '0', exp)
+            ans = ans._fix(context)
+            return ans
+        if not self:
+            exp = max(exp, other._exp - context.prec-1)
+            ans = other._rescale(exp, context.rounding)
+            ans = ans._fix(context)
+            return ans
+        if not other:
+            exp = max(exp, self._exp - context.prec-1)
+            ans = self._rescale(exp, context.rounding)
+            ans = ans._fix(context)
+            return ans
+
+        op1 = _WorkRep(self)
+        op2 = _WorkRep(other)
+        op1, op2 = _normalize(op1, op2, context.prec)
+
+        result = _WorkRep()
+        if op1.sign != op2.sign:
+            # Equal and opposite
+            if op1.int == op2.int:
+                ans = _dec_from_triple(negativezero, '0', exp)
+                ans = ans._fix(context)
+                return ans
+            if op1.int < op2.int:
+                op1, op2 = op2, op1
+                # OK, now abs(op1) > abs(op2)
+            if op1.sign == 1:
+                result.sign = 1
+                op1.sign, op2.sign = op2.sign, op1.sign
+            else:
+                result.sign = 0
+                # So we know the sign, and op1 > 0.
+        elif op1.sign == 1:
+            result.sign = 1
+            op1.sign, op2.sign = (0, 0)
+        else:
+            result.sign = 0
+        # Now, op1 > abs(op2) > 0
+
+        if op2.sign == 0:
+            result.int = op1.int + op2.int
+        else:
+            result.int = op1.int - op2.int
+
+        result.exp = op1.exp
+        ans = Decimal(result)
+        ans = ans._fix(context)
+        return ans
+
+    __radd__ = __add__
+
+    def __sub__(self, other, context=None):
+        """Return self - other"""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if self._is_special or other._is_special:
+            ans = self._check_nans(other, context=context)
+            if ans:
+                return ans
+
+        # self - other is computed as self + other.copy_negate()
+        return self.__add__(other.copy_negate(), context=context)
+
+    def __rsub__(self, other, context=None):
+        """Return other - self"""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        return other.__sub__(self, context=context)
+
+    def __mul__(self, other, context=None):
+        """Return self * other.
+
+        (+-) INF * 0 (or its reverse) raise InvalidOperation.
+        """
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if context is None:
+            context = getcontext()
+
+        resultsign = self._sign ^ other._sign
+
+        if self._is_special or other._is_special:
+            ans = self._check_nans(other, context)
+            if ans:
+                return ans
+
+            if self._isinfinity():
+                if not other:
+                    return context._raise_error(InvalidOperation, '(+-)INF * 0')
+                return _SignedInfinity[resultsign]
+
+            if other._isinfinity():
+                if not self:
+                    return context._raise_error(InvalidOperation, '0 * (+-)INF')
+                return _SignedInfinity[resultsign]
+
+        resultexp = self._exp + other._exp
+
+        # Special case for multiplying by zero
+        if not self or not other:
+            ans = _dec_from_triple(resultsign, '0', resultexp)
+            # Fixing in case the exponent is out of bounds
+            ans = ans._fix(context)
+            return ans
+
+        # Special case for multiplying by power of 10
+        if self._int == '1':
+            ans = _dec_from_triple(resultsign, other._int, resultexp)
+            ans = ans._fix(context)
+            return ans
+        if other._int == '1':
+            ans = _dec_from_triple(resultsign, self._int, resultexp)
+            ans = ans._fix(context)
+            return ans
+
+        op1 = _WorkRep(self)
+        op2 = _WorkRep(other)
+
+        ans = _dec_from_triple(resultsign, str(op1.int * op2.int), resultexp)
+        ans = ans._fix(context)
+
+        return ans
+    __rmul__ = __mul__
+
+    def __truediv__(self, other, context=None):
+        """Return self / other."""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return NotImplemented
+
+        if context is None:
+            context = getcontext()
+
+        sign = self._sign ^ other._sign
+
+        if self._is_special or other._is_special:
+            ans = self._check_nans(other, context)
+            if ans:
+                return ans
+
+            if self._isinfinity() and other._isinfinity():
+                return context._raise_error(InvalidOperation, '(+-)INF/(+-)INF')
+
+            if self._isinfinity():
+                return _SignedInfinity[sign]
+
+            if other._isinfinity():
+                context._raise_error(Clamped, 'Division by infinity')
+                return _dec_from_triple(sign, '0', context.Etiny())
+
+        # Special cases for zeroes
+        if not other:
+            if not self:
+                return context._raise_error(DivisionUndefined, '0 / 0')
+            return context._raise_error(DivisionByZero, 'x / 0', sign)
+
+        if not self:
+            exp = self._exp - other._exp
+            coeff = 0
+        else:
+            # OK, so neither = 0, INF or NaN
+            shift = len(other._int) - len(self._int) + context.prec + 1
+            exp = self._exp - other._exp - shift
+            op1 = _WorkRep(self)
+            op2 = _WorkRep(other)
+            if shift >= 0:
+                coeff, remainder = divmod(op1.int * 10**shift, op2.int)
+            else:
+                coeff, remainder = divmod(op1.int, op2.int * 10**-shift)
+            if remainder:
+                # result is not exact; adjust to ensure correct rounding
+                if coeff % 5 == 0:
+                    coeff += 1
+            else:
+                # result is exact; get as close to ideal exponent as possible
+                ideal_exp = self._exp - other._exp
+                while exp < ideal_exp and coeff % 10 == 0:
+                    coeff //= 10
+                    exp += 1
+
+        ans = _dec_from_triple(sign, str(coeff), exp)
+        return ans._fix(context)
+
+    def _divide(self, other, context):
+        """Return (self // other, self % other), to context.prec precision.
+
+        Assumes that neither self nor other is a NaN, that self is not
+        infinite and that other is nonzero.
+        """
+        sign = self._sign ^ other._sign
+        if other._isinfinity():
+            ideal_exp = self._exp
+        else:
+            ideal_exp = min(self._exp, other._exp)
+
+        expdiff = self.adjusted() - other.adjusted()
+        if not self or other._isinfinity() or expdiff <= -2:
+            return (_dec_from_triple(sign, '0', 0),
+                    self._rescale(ideal_exp, context.rounding))
+        if expdiff <= context.prec:
+            op1 = _WorkRep(self)
+            op2 = _WorkRep(other)
+            if op1.exp >= op2.exp:
+                op1.int *= 10**(op1.exp - op2.exp)
+            else:
+                op2.int *= 10**(op2.exp - op1.exp)
+            q, r = divmod(op1.int, op2.int)
+            if q < 10**context.prec:
+                return (_dec_from_triple(sign, str(q), 0),
+                        _dec_from_triple(self._sign, str(r), ideal_exp))
+
+        # Here the quotient is too large to be representable
+        ans = context._raise_error(DivisionImpossible,
+                                   'quotient too large in //, % or divmod')
+        return ans, ans
+
+    def __rtruediv__(self, other, context=None):
+        """Swaps self/other and returns __truediv__."""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+        return other.__truediv__(self, context=context)
+
+    def __divmod__(self, other, context=None):
+        """
+        Return (self // other, self % other)
+        """
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if context is None:
+            context = getcontext()
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return (ans, ans)
+
+        sign = self._sign ^ other._sign
+        if self._isinfinity():
+            if other._isinfinity():
+                ans = context._raise_error(InvalidOperation, 'divmod(INF, INF)')
+                return ans, ans
+            else:
+                return (_SignedInfinity[sign],
+                        context._raise_error(InvalidOperation, 'INF % x'))
+
+        if not other:
+            if not self:
+                ans = context._raise_error(DivisionUndefined, 'divmod(0, 0)')
+                return ans, ans
+            else:
+                return (context._raise_error(DivisionByZero, 'x // 0', sign),
+                        context._raise_error(InvalidOperation, 'x % 0'))
+
+        quotient, remainder = self._divide(other, context)
+        remainder = remainder._fix(context)
+        return quotient, remainder
+
+    def __rdivmod__(self, other, context=None):
+        """Swaps self/other and returns __divmod__."""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+        return other.__divmod__(self, context=context)
+
+    def __mod__(self, other, context=None):
+        """
+        self % other
+        """
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if context is None:
+            context = getcontext()
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        if self._isinfinity():
+            return context._raise_error(InvalidOperation, 'INF % x')
+        elif not other:
+            if self:
+                return context._raise_error(InvalidOperation, 'x % 0')
+            else:
+                return context._raise_error(DivisionUndefined, '0 % 0')
+
+        remainder = self._divide(other, context)[1]
+        remainder = remainder._fix(context)
+        return remainder
+
+    def __rmod__(self, other, context=None):
+        """Swaps self/other and returns __mod__."""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+        return other.__mod__(self, context=context)
+
+    def remainder_near(self, other, context=None):
+        """
+        Remainder nearest to 0-  abs(remainder-near) <= other/2
+        """
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        # self == +/-infinity -> InvalidOperation
+        if self._isinfinity():
+            return context._raise_error(InvalidOperation,
+                                        'remainder_near(infinity, x)')
+
+        # other == 0 -> either InvalidOperation or DivisionUndefined
+        if not other:
+            if self:
+                return context._raise_error(InvalidOperation,
+                                            'remainder_near(x, 0)')
+            else:
+                return context._raise_error(DivisionUndefined,
+                                            'remainder_near(0, 0)')
+
+        # other = +/-infinity -> remainder = self
+        if other._isinfinity():
+            ans = Decimal(self)
+            return ans._fix(context)
+
+        # self = 0 -> remainder = self, with ideal exponent
+        ideal_exponent = min(self._exp, other._exp)
+        if not self:
+            ans = _dec_from_triple(self._sign, '0', ideal_exponent)
+            return ans._fix(context)
+
+        # catch most cases of large or small quotient
+        expdiff = self.adjusted() - other.adjusted()
+        if expdiff >= context.prec + 1:
+            # expdiff >= prec+1 => abs(self/other) > 10**prec
+            return context._raise_error(DivisionImpossible)
+        if expdiff <= -2:
+            # expdiff <= -2 => abs(self/other) < 0.1
+            ans = self._rescale(ideal_exponent, context.rounding)
+            return ans._fix(context)
+
+        # adjust both arguments to have the same exponent, then divide
+        op1 = _WorkRep(self)
+        op2 = _WorkRep(other)
+        if op1.exp >= op2.exp:
+            op1.int *= 10**(op1.exp - op2.exp)
+        else:
+            op2.int *= 10**(op2.exp - op1.exp)
+        q, r = divmod(op1.int, op2.int)
+        # remainder is r*10**ideal_exponent; other is +/-op2.int *
+        # 10**ideal_exponent.   Apply correction to ensure that
+        # abs(remainder) <= abs(other)/2
+        if 2*r + (q&1) > op2.int:
+            r -= op2.int
+            q += 1
+
+        if q >= 10**context.prec:
+            return context._raise_error(DivisionImpossible)
+
+        # result has same sign as self unless r is negative
+        sign = self._sign
+        if r < 0:
+            sign = 1-sign
+            r = -r
+
+        ans = _dec_from_triple(sign, str(r), ideal_exponent)
+        return ans._fix(context)
+
+    def __floordiv__(self, other, context=None):
+        """self // other"""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if context is None:
+            context = getcontext()
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        if self._isinfinity():
+            if other._isinfinity():
+                return context._raise_error(InvalidOperation, 'INF // INF')
+            else:
+                return _SignedInfinity[self._sign ^ other._sign]
+
+        if not other:
+            if self:
+                return context._raise_error(DivisionByZero, 'x // 0',
+                                            self._sign ^ other._sign)
+            else:
+                return context._raise_error(DivisionUndefined, '0 // 0')
+
+        return self._divide(other, context)[0]
+
+    def __rfloordiv__(self, other, context=None):
+        """Swaps self/other and returns __floordiv__."""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+        return other.__floordiv__(self, context=context)
+
+    def __float__(self):
+        """Float representation."""
+        if self._isnan():
+            if self.is_snan():
+                raise ValueError("Cannot convert signaling NaN to float")
+            s = "-nan" if self._sign else "nan"
+        else:
+            s = str(self)
+        return float(s)
+
+    def __int__(self):
+        """Converts self to an int, truncating if necessary."""
+        if self._is_special:
+            if self._isnan():
+                raise ValueError("Cannot convert NaN to integer")
+            elif self._isinfinity():
+                raise OverflowError("Cannot convert infinity to integer")
+        s = (-1)**self._sign
+        if self._exp >= 0:
+            return s*int(self._int)*10**self._exp
+        else:
+            return s*int(self._int[:self._exp] or '0')
+
+    __trunc__ = __int__
+
+    def real(self):
+        return self
+    real = property(real)
+
+    def imag(self):
+        return Decimal(0)
+    imag = property(imag)
+
+    def conjugate(self):
+        return self
+
+    def __complex__(self):
+        return complex(float(self))
+
+    def _fix_nan(self, context):
+        """Decapitate the payload of a NaN to fit the context"""
+        payload = self._int
+
+        # maximum length of payload is precision if clamp=0,
+        # precision-1 if clamp=1.
+        max_payload_len = context.prec - context.clamp
+        if len(payload) > max_payload_len:
+            payload = payload[len(payload)-max_payload_len:].lstrip('0')
+            return _dec_from_triple(self._sign, payload, self._exp, True)
+        return Decimal(self)
+
+    def _fix(self, context):
+        """Round if it is necessary to keep self within prec precision.
+
+        Rounds and fixes the exponent.  Does not raise on a sNaN.
+
+        Arguments:
+        self - Decimal instance
+        context - context used.
+        """
+
+        if self._is_special:
+            if self._isnan():
+                # decapitate payload if necessary
+                return self._fix_nan(context)
+            else:
+                # self is +/-Infinity; return unaltered
+                return Decimal(self)
+
+        # if self is zero then exponent should be between Etiny and
+        # Emax if clamp==0, and between Etiny and Etop if clamp==1.
+        Etiny = context.Etiny()
+        Etop = context.Etop()
+        if not self:
+            exp_max = [context.Emax, Etop][context.clamp]
+            new_exp = min(max(self._exp, Etiny), exp_max)
+            if new_exp != self._exp:
+                context._raise_error(Clamped)
+                return _dec_from_triple(self._sign, '0', new_exp)
+            else:
+                return Decimal(self)
+
+        # exp_min is the smallest allowable exponent of the result,
+        # equal to max(self.adjusted()-context.prec+1, Etiny)
+        exp_min = len(self._int) + self._exp - context.prec
+        if exp_min > Etop:
+            # overflow: exp_min > Etop iff self.adjusted() > Emax
+            ans = context._raise_error(Overflow, 'above Emax', self._sign)
+            context._raise_error(Inexact)
+            context._raise_error(Rounded)
+            return ans
+
+        self_is_subnormal = exp_min < Etiny
+        if self_is_subnormal:
+            exp_min = Etiny
+
+        # round if self has too many digits
+        if self._exp < exp_min:
+            digits = len(self._int) + self._exp - exp_min
+            if digits < 0:
+                self = _dec_from_triple(self._sign, '1', exp_min-1)
+                digits = 0
+            rounding_method = self._pick_rounding_function[context.rounding]
+            changed = rounding_method(self, digits)
+            coeff = self._int[:digits] or '0'
+            if changed > 0:
+                coeff = str(int(coeff)+1)
+                if len(coeff) > context.prec:
+                    coeff = coeff[:-1]
+                    exp_min += 1
+
+            # check whether the rounding pushed the exponent out of range
+            if exp_min > Etop:
+                ans = context._raise_error(Overflow, 'above Emax', self._sign)
+            else:
+                ans = _dec_from_triple(self._sign, coeff, exp_min)
+
+            # raise the appropriate signals, taking care to respect
+            # the precedence described in the specification
+            if changed and self_is_subnormal:
+                context._raise_error(Underflow)
+            if self_is_subnormal:
+                context._raise_error(Subnormal)
+            if changed:
+                context._raise_error(Inexact)
+            context._raise_error(Rounded)
+            if not ans:
+                # raise Clamped on underflow to 0
+                context._raise_error(Clamped)
+            return ans
+
+        if self_is_subnormal:
+            context._raise_error(Subnormal)
+
+        # fold down if clamp == 1 and self has too few digits
+        if context.clamp == 1 and self._exp > Etop:
+            context._raise_error(Clamped)
+            self_padded = self._int + '0'*(self._exp - Etop)
+            return _dec_from_triple(self._sign, self_padded, Etop)
+
+        # here self was representable to begin with; return unchanged
+        return Decimal(self)
+
+    # for each of the rounding functions below:
+    #   self is a finite, nonzero Decimal
+    #   prec is an integer satisfying 0 <= prec < len(self._int)
+    #
+    # each function returns either -1, 0, or 1, as follows:
+    #   1 indicates that self should be rounded up (away from zero)
+    #   0 indicates that self should be truncated, and that all the
+    #     digits to be truncated are zeros (so the value is unchanged)
+    #  -1 indicates that there are nonzero digits to be truncated
+
+    def _round_down(self, prec):
+        """Also known as round-towards-0, truncate."""
+        if _all_zeros(self._int, prec):
+            return 0
+        else:
+            return -1
+
+    def _round_up(self, prec):
+        """Rounds away from 0."""
+        return -self._round_down(prec)
+
+    def _round_half_up(self, prec):
+        """Rounds 5 up (away from 0)"""
+        if self._int[prec] in '56789':
+            return 1
+        elif _all_zeros(self._int, prec):
+            return 0
+        else:
+            return -1
+
+    def _round_half_down(self, prec):
+        """Round 5 down"""
+        if _exact_half(self._int, prec):
+            return -1
+        else:
+            return self._round_half_up(prec)
+
+    def _round_half_even(self, prec):
+        """Round 5 to even, rest to nearest."""
+        if _exact_half(self._int, prec) and \
+                (prec == 0 or self._int[prec-1] in '02468'):
+            return -1
+        else:
+            return self._round_half_up(prec)
+
+    def _round_ceiling(self, prec):
+        """Rounds up (not away from 0 if negative.)"""
+        if self._sign:
+            return self._round_down(prec)
+        else:
+            return -self._round_down(prec)
+
+    def _round_floor(self, prec):
+        """Rounds down (not towards 0 if negative)"""
+        if not self._sign:
+            return self._round_down(prec)
+        else:
+            return -self._round_down(prec)
+
+    def _round_05up(self, prec):
+        """Round down unless digit prec-1 is 0 or 5."""
+        if prec and self._int[prec-1] not in '05':
+            return self._round_down(prec)
+        else:
+            return -self._round_down(prec)
+
+    _pick_rounding_function = dict(
+        ROUND_DOWN = _round_down,
+        ROUND_UP = _round_up,
+        ROUND_HALF_UP = _round_half_up,
+        ROUND_HALF_DOWN = _round_half_down,
+        ROUND_HALF_EVEN = _round_half_even,
+        ROUND_CEILING = _round_ceiling,
+        ROUND_FLOOR = _round_floor,
+        ROUND_05UP = _round_05up,
+    )
+
+    def __round__(self, n=None):
+        """Round self to the nearest integer, or to a given precision.
+
+        If only one argument is supplied, round a finite Decimal
+        instance self to the nearest integer.  If self is infinite or
+        a NaN then a Python exception is raised.  If self is finite
+        and lies exactly halfway between two integers then it is
+        rounded to the integer with even last digit.
+
+        >>> round(Decimal('123.456'))
+        123
+        >>> round(Decimal('-456.789'))
+        -457
+        >>> round(Decimal('-3.0'))
+        -3
+        >>> round(Decimal('2.5'))
+        2
+        >>> round(Decimal('3.5'))
+        4
+        >>> round(Decimal('Inf'))
+        Traceback (most recent call last):
+          ...
+        OverflowError: cannot round an infinity
+        >>> round(Decimal('NaN'))
+        Traceback (most recent call last):
+          ...
+        ValueError: cannot round a NaN
+
+        If a second argument n is supplied, self is rounded to n
+        decimal places using the rounding mode for the current
+        context.
+
+        For an integer n, round(self, -n) is exactly equivalent to
+        self.quantize(Decimal('1En')).
+
+        >>> round(Decimal('123.456'), 0)
+        Decimal('123')
+        >>> round(Decimal('123.456'), 2)
+        Decimal('123.46')
+        >>> round(Decimal('123.456'), -2)
+        Decimal('1E+2')
+        >>> round(Decimal('-Infinity'), 37)
+        Decimal('NaN')
+        >>> round(Decimal('sNaN123'), 0)
+        Decimal('NaN123')
+
+        """
+        if n is not None:
+            # two-argument form: use the equivalent quantize call
+            if not isinstance(n, int):
+                raise TypeError('Second argument to round should be integral')
+            exp = _dec_from_triple(0, '1', -n)
+            return self.quantize(exp)
+
+        # one-argument form
+        if self._is_special:
+            if self.is_nan():
+                raise ValueError("cannot round a NaN")
+            else:
+                raise OverflowError("cannot round an infinity")
+        return int(self._rescale(0, ROUND_HALF_EVEN))
+
+    def __floor__(self):
+        """Return the floor of self, as an integer.
+
+        For a finite Decimal instance self, return the greatest
+        integer n such that n <= self.  If self is infinite or a NaN
+        then a Python exception is raised.
+
+        """
+        if self._is_special:
+            if self.is_nan():
+                raise ValueError("cannot round a NaN")
+            else:
+                raise OverflowError("cannot round an infinity")
+        return int(self._rescale(0, ROUND_FLOOR))
+
+    def __ceil__(self):
+        """Return the ceiling of self, as an integer.
+
+        For a finite Decimal instance self, return the least integer n
+        such that n >= self.  If self is infinite or a NaN then a
+        Python exception is raised.
+
+        """
+        if self._is_special:
+            if self.is_nan():
+                raise ValueError("cannot round a NaN")
+            else:
+                raise OverflowError("cannot round an infinity")
+        return int(self._rescale(0, ROUND_CEILING))
+
+    def fma(self, other, third, context=None):
+        """Fused multiply-add.
+
+        Returns self*other+third with no rounding of the intermediate
+        product self*other.
+
+        self and other are multiplied together, with no rounding of
+        the result.  The third operand is then added to the result,
+        and a single final rounding is performed.
+        """
+
+        other = _convert_other(other, raiseit=True)
+        third = _convert_other(third, raiseit=True)
+
+        # compute product; raise InvalidOperation if either operand is
+        # a signaling NaN or if the product is zero times infinity.
+        if self._is_special or other._is_special:
+            if context is None:
+                context = getcontext()
+            if self._exp == 'N':
+                return context._raise_error(InvalidOperation, 'sNaN', self)
+            if other._exp == 'N':
+                return context._raise_error(InvalidOperation, 'sNaN', other)
+            if self._exp == 'n':
+                product = self
+            elif other._exp == 'n':
+                product = other
+            elif self._exp == 'F':
+                if not other:
+                    return context._raise_error(InvalidOperation,
+                                                'INF * 0 in fma')
+                product = _SignedInfinity[self._sign ^ other._sign]
+            elif other._exp == 'F':
+                if not self:
+                    return context._raise_error(InvalidOperation,
+                                                '0 * INF in fma')
+                product = _SignedInfinity[self._sign ^ other._sign]
+        else:
+            product = _dec_from_triple(self._sign ^ other._sign,
+                                       str(int(self._int) * int(other._int)),
+                                       self._exp + other._exp)
+
+        return product.__add__(third, context)
+
+    def _power_modulo(self, other, modulo, context=None):
+        """Three argument version of __pow__"""
+
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+        modulo = _convert_other(modulo)
+        if modulo is NotImplemented:
+            return modulo
+
+        if context is None:
+            context = getcontext()
+
+        # deal with NaNs: if there are any sNaNs then first one wins,
+        # (i.e. behaviour for NaNs is identical to that of fma)
+        self_is_nan = self._isnan()
+        other_is_nan = other._isnan()
+        modulo_is_nan = modulo._isnan()
+        if self_is_nan or other_is_nan or modulo_is_nan:
+            if self_is_nan == 2:
+                return context._raise_error(InvalidOperation, 'sNaN',
+                                        self)
+            if other_is_nan == 2:
+                return context._raise_error(InvalidOperation, 'sNaN',
+                                        other)
+            if modulo_is_nan == 2:
+                return context._raise_error(InvalidOperation, 'sNaN',
+                                        modulo)
+            if self_is_nan:
+                return self._fix_nan(context)
+            if other_is_nan:
+                return other._fix_nan(context)
+            return modulo._fix_nan(context)
+
+        # check inputs: we apply same restrictions as Python's pow()
+        if not (self._isinteger() and
+                other._isinteger() and
+                modulo._isinteger()):
+            return context._raise_error(InvalidOperation,
+                                        'pow() 3rd argument not allowed '
+                                        'unless all arguments are integers')
+        if other < 0:
+            return context._raise_error(InvalidOperation,
+                                        'pow() 2nd argument cannot be '
+                                        'negative when 3rd argument specified')
+        if not modulo:
+            return context._raise_error(InvalidOperation,
+                                        'pow() 3rd argument cannot be 0')
+
+        # additional restriction for decimal: the modulus must be less
+        # than 10**prec in absolute value
+        if modulo.adjusted() >= context.prec:
+            return context._raise_error(InvalidOperation,
+                                        'insufficient precision: pow() 3rd '
+                                        'argument must not have more than '
+                                        'precision digits')
+
+        # define 0**0 == NaN, for consistency with two-argument pow
+        # (even though it hurts!)
+        if not other and not self:
+            return context._raise_error(InvalidOperation,
+                                        'at least one of pow() 1st argument '
+                                        'and 2nd argument must be nonzero ;'
+                                        '0**0 is not defined')
+
+        # compute sign of result
+        if other._iseven():
+            sign = 0
+        else:
+            sign = self._sign
+
+        # convert modulo to a Python integer, and self and other to
+        # Decimal integers (i.e. force their exponents to be >= 0)
+        modulo = abs(int(modulo))
+        base = _WorkRep(self.to_integral_value())
+        exponent = _WorkRep(other.to_integral_value())
+
+        # compute result using integer pow()
+        base = (base.int % modulo * pow(10, base.exp, modulo)) % modulo
+        for i in range(exponent.exp):
+            base = pow(base, 10, modulo)
+        base = pow(base, exponent.int, modulo)
+
+        return _dec_from_triple(sign, str(base), 0)
+
+    def _power_exact(self, other, p):
+        """Attempt to compute self**other exactly.
+
+        Given Decimals self and other and an integer p, attempt to
+        compute an exact result for the power self**other, with p
+        digits of precision.  Return None if self**other is not
+        exactly representable in p digits.
+
+        Assumes that elimination of special cases has already been
+        performed: self and other must both be nonspecial; self must
+        be positive and not numerically equal to 1; other must be
+        nonzero.  For efficiency, other._exp should not be too large,
+        so that 10**abs(other._exp) is a feasible calculation."""
+
+        # In the comments below, we write x for the value of self and y for the
+        # value of other.  Write x = xc*10**xe and abs(y) = yc*10**ye, with xc
+        # and yc positive integers not divisible by 10.
+
+        # The main purpose of this method is to identify the *failure*
+        # of x**y to be exactly representable with as little effort as
+        # possible.  So we look for cheap and easy tests that
+        # eliminate the possibility of x**y being exact.  Only if all
+        # these tests are passed do we go on to actually compute x**y.
+
+        # Here's the main idea.  Express y as a rational number m/n, with m and
+        # n relatively prime and n>0.  Then for x**y to be exactly
+        # representable (at *any* precision), xc must be the nth power of a
+        # positive integer and xe must be divisible by n.  If y is negative
+        # then additionally xc must be a power of either 2 or 5, hence a power
+        # of 2**n or 5**n.
+        #
+        # There's a limit to how small |y| can be: if y=m/n as above
+        # then:
+        #
+        #  (1) if xc != 1 then for the result to be representable we
+        #      need xc**(1/n) >= 2, and hence also xc**|y| >= 2.  So
+        #      if |y| <= 1/nbits(xc) then xc < 2**nbits(xc) <=
+        #      2**(1/|y|), hence xc**|y| < 2 and the result is not
+        #      representable.
+        #
+        #  (2) if xe != 0, |xe|*(1/n) >= 1, so |xe|*|y| >= 1.  Hence if
+        #      |y| < 1/|xe| then the result is not representable.
+        #
+        # Note that since x is not equal to 1, at least one of (1) and
+        # (2) must apply.  Now |y| < 1/nbits(xc) iff |yc|*nbits(xc) <
+        # 10**-ye iff len(str(|yc|*nbits(xc)) <= -ye.
+        #
+        # There's also a limit to how large y can be, at least if it's
+        # positive: the normalized result will have coefficient xc**y,
+        # so if it's representable then xc**y < 10**p, and y <
+        # p/log10(xc).  Hence if y*log10(xc) >= p then the result is
+        # not exactly representable.
+
+        # if len(str(abs(yc*xe)) <= -ye then abs(yc*xe) < 10**-ye,
+        # so |y| < 1/xe and the result is not representable.
+        # Similarly, len(str(abs(yc)*xc_bits)) <= -ye implies |y|
+        # < 1/nbits(xc).
+
+        x = _WorkRep(self)
+        xc, xe = x.int, x.exp
+        while xc % 10 == 0:
+            xc //= 10
+            xe += 1
+
+        y = _WorkRep(other)
+        yc, ye = y.int, y.exp
+        while yc % 10 == 0:
+            yc //= 10
+            ye += 1
+
+        # case where xc == 1: result is 10**(xe*y), with xe*y
+        # required to be an integer
+        if xc == 1:
+            xe *= yc
+            # result is now 10**(xe * 10**ye);  xe * 10**ye must be integral
+            while xe % 10 == 0:
+                xe //= 10
+                ye += 1
+            if ye < 0:
+                return None
+            exponent = xe * 10**ye
+            if y.sign == 1:
+                exponent = -exponent
+            # if other is a nonnegative integer, use ideal exponent
+            if other._isinteger() and other._sign == 0:
+                ideal_exponent = self._exp*int(other)
+                zeros = min(exponent-ideal_exponent, p-1)
+            else:
+                zeros = 0
+            return _dec_from_triple(0, '1' + '0'*zeros, exponent-zeros)
+
+        # case where y is negative: xc must be either a power
+        # of 2 or a power of 5.
+        if y.sign == 1:
+            last_digit = xc % 10
+            if last_digit in (2,4,6,8):
+                # quick test for power of 2
+                if xc & -xc != xc:
+                    return None
+                # now xc is a power of 2; e is its exponent
+                e = _nbits(xc)-1
+
+                # We now have:
+                #
+                #   x = 2**e * 10**xe, e > 0, and y < 0.
+                #
+                # The exact result is:
+                #
+                #   x**y = 5**(-e*y) * 10**(e*y + xe*y)
+                #
+                # provided that both e*y and xe*y are integers.  Note that if
+                # 5**(-e*y) >= 10**p, then the result can't be expressed
+                # exactly with p digits of precision.
+                #
+                # Using the above, we can guard against large values of ye.
+                # 93/65 is an upper bound for log(10)/log(5), so if
+                #
+                #   ye >= len(str(93*p//65))
+                #
+                # then
+                #
+                #   -e*y >= -y >= 10**ye > 93*p/65 > p*log(10)/log(5),
+                #
+                # so 5**(-e*y) >= 10**p, and the coefficient of the result
+                # can't be expressed in p digits.
+
+                # emax >= largest e such that 5**e < 10**p.
+                emax = p*93//65
+                if ye >= len(str(emax)):
+                    return None
+
+                # Find -e*y and -xe*y; both must be integers
+                e = _decimal_lshift_exact(e * yc, ye)
+                xe = _decimal_lshift_exact(xe * yc, ye)
+                if e is None or xe is None:
+                    return None
+
+                if e > emax:
+                    return None
+                xc = 5**e
+
+            elif last_digit == 5:
+                # e >= log_5(xc) if xc is a power of 5; we have
+                # equality all the way up to xc=5**2658
+                e = _nbits(xc)*28//65
+                xc, remainder = divmod(5**e, xc)
+                if remainder:
+                    return None
+                while xc % 5 == 0:
+                    xc //= 5
+                    e -= 1
+
+                # Guard against large values of ye, using the same logic as in
+                # the 'xc is a power of 2' branch.  10/3 is an upper bound for
+                # log(10)/log(2).
+                emax = p*10//3
+                if ye >= len(str(emax)):
+                    return None
+
+                e = _decimal_lshift_exact(e * yc, ye)
+                xe = _decimal_lshift_exact(xe * yc, ye)
+                if e is None or xe is None:
+                    return None
+
+                if e > emax:
+                    return None
+                xc = 2**e
+            else:
+                return None
+
+            if xc >= 10**p:
+                return None
+            xe = -e-xe
+            return _dec_from_triple(0, str(xc), xe)
+
+        # now y is positive; find m and n such that y = m/n
+        if ye >= 0:
+            m, n = yc*10**ye, 1
+        else:
+            if xe != 0 and len(str(abs(yc*xe))) <= -ye:
+                return None
+            xc_bits = _nbits(xc)
+            if xc != 1 and len(str(abs(yc)*xc_bits)) <= -ye:
+                return None
+            m, n = yc, 10**(-ye)
+            while m % 2 == n % 2 == 0:
+                m //= 2
+                n //= 2
+            while m % 5 == n % 5 == 0:
+                m //= 5
+                n //= 5
+
+        # compute nth root of xc*10**xe
+        if n > 1:
+            # if 1 < xc < 2**n then xc isn't an nth power
+            if xc != 1 and xc_bits <= n:
+                return None
+
+            xe, rem = divmod(xe, n)
+            if rem != 0:
+                return None
+
+            # compute nth root of xc using Newton's method
+            a = 1 << -(-_nbits(xc)//n) # initial estimate
+            while True:
+                q, r = divmod(xc, a**(n-1))
+                if a <= q:
+                    break
+                else:
+                    a = (a*(n-1) + q)//n
+            if not (a == q and r == 0):
+                return None
+            xc = a
+
+        # now xc*10**xe is the nth root of the original xc*10**xe
+        # compute mth power of xc*10**xe
+
+        # if m > p*100//_log10_lb(xc) then m > p/log10(xc), hence xc**m >
+        # 10**p and the result is not representable.
+        if xc > 1 and m > p*100//_log10_lb(xc):
+            return None
+        xc = xc**m
+        xe *= m
+        if xc > 10**p:
+            return None
+
+        # by this point the result *is* exactly representable
+        # adjust the exponent to get as close as possible to the ideal
+        # exponent, if necessary
+        str_xc = str(xc)
+        if other._isinteger() and other._sign == 0:
+            ideal_exponent = self._exp*int(other)
+            zeros = min(xe-ideal_exponent, p-len(str_xc))
+        else:
+            zeros = 0
+        return _dec_from_triple(0, str_xc+'0'*zeros, xe-zeros)
+
+    def __pow__(self, other, modulo=None, context=None):
+        """Return self ** other [ % modulo].
+
+        With two arguments, compute self**other.
+
+        With three arguments, compute (self**other) % modulo.  For the
+        three argument form, the following restrictions on the
+        arguments hold:
+
+         - all three arguments must be integral
+         - other must be nonnegative
+         - either self or other (or both) must be nonzero
+         - modulo must be nonzero and must have at most p digits,
+           where p is the context precision.
+
+        If any of these restrictions is violated the InvalidOperation
+        flag is raised.
+
+        The result of pow(self, other, modulo) is identical to the
+        result that would be obtained by computing (self**other) %
+        modulo with unbounded precision, but is computed more
+        efficiently.  It is always exact.
+        """
+
+        if modulo is not None:
+            return self._power_modulo(other, modulo, context)
+
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+
+        if context is None:
+            context = getcontext()
+
+        # either argument is a NaN => result is NaN
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        # 0**0 = NaN (!), x**0 = 1 for nonzero x (including +/-Infinity)
+        if not other:
+            if not self:
+                return context._raise_error(InvalidOperation, '0 ** 0')
+            else:
+                return _One
+
+        # result has sign 1 iff self._sign is 1 and other is an odd integer
+        result_sign = 0
+        if self._sign == 1:
+            if other._isinteger():
+                if not other._iseven():
+                    result_sign = 1
+            else:
+                # -ve**noninteger = NaN
+                # (-0)**noninteger = 0**noninteger
+                if self:
+                    return context._raise_error(InvalidOperation,
+                        'x ** y with x negative and y not an integer')
+            # negate self, without doing any unwanted rounding
+            self = self.copy_negate()
+
+        # 0**(+ve or Inf)= 0; 0**(-ve or -Inf) = Infinity
+        if not self:
+            if other._sign == 0:
+                return _dec_from_triple(result_sign, '0', 0)
+            else:
+                return _SignedInfinity[result_sign]
+
+        # Inf**(+ve or Inf) = Inf; Inf**(-ve or -Inf) = 0
+        if self._isinfinity():
+            if other._sign == 0:
+                return _SignedInfinity[result_sign]
+            else:
+                return _dec_from_triple(result_sign, '0', 0)
+
+        # 1**other = 1, but the choice of exponent and the flags
+        # depend on the exponent of self, and on whether other is a
+        # positive integer, a negative integer, or neither
+        if self == _One:
+            if other._isinteger():
+                # exp = max(self._exp*max(int(other), 0),
+                # 1-context.prec) but evaluating int(other) directly
+                # is dangerous until we know other is small (other
+                # could be 1e999999999)
+                if other._sign == 1:
+                    multiplier = 0
+                elif other > context.prec:
+                    multiplier = context.prec
+                else:
+                    multiplier = int(other)
+
+                exp = self._exp * multiplier
+                if exp < 1-context.prec:
+                    exp = 1-context.prec
+                    context._raise_error(Rounded)
+            else:
+                context._raise_error(Inexact)
+                context._raise_error(Rounded)
+                exp = 1-context.prec
+
+            return _dec_from_triple(result_sign, '1'+'0'*-exp, exp)
+
+        # compute adjusted exponent of self
+        self_adj = self.adjusted()
+
+        # self ** infinity is infinity if self > 1, 0 if self < 1
+        # self ** -infinity is infinity if self < 1, 0 if self > 1
+        if other._isinfinity():
+            if (other._sign == 0) == (self_adj < 0):
+                return _dec_from_triple(result_sign, '0', 0)
+            else:
+                return _SignedInfinity[result_sign]
+
+        # from here on, the result always goes through the call
+        # to _fix at the end of this function.
+        ans = None
+        exact = False
+
+        # crude test to catch cases of extreme overflow/underflow.  If
+        # log10(self)*other >= 10**bound and bound >= len(str(Emax))
+        # then 10**bound >= 10**len(str(Emax)) >= Emax+1 and hence
+        # self**other >= 10**(Emax+1), so overflow occurs.  The test
+        # for underflow is similar.
+        bound = self._log10_exp_bound() + other.adjusted()
+        if (self_adj >= 0) == (other._sign == 0):
+            # self > 1 and other +ve, or self < 1 and other -ve
+            # possibility of overflow
+            if bound >= len(str(context.Emax)):
+                ans = _dec_from_triple(result_sign, '1', context.Emax+1)
+        else:
+            # self > 1 and other -ve, or self < 1 and other +ve
+            # possibility of underflow to 0
+            Etiny = context.Etiny()
+            if bound >= len(str(-Etiny)):
+                ans = _dec_from_triple(result_sign, '1', Etiny-1)
+
+        # try for an exact result with precision +1
+        if ans is None:
+            ans = self._power_exact(other, context.prec + 1)
+            if ans is not None:
+                if result_sign == 1:
+                    ans = _dec_from_triple(1, ans._int, ans._exp)
+                exact = True
+
+        # usual case: inexact result, x**y computed directly as exp(y*log(x))
+        if ans is None:
+            p = context.prec
+            x = _WorkRep(self)
+            xc, xe = x.int, x.exp
+            y = _WorkRep(other)
+            yc, ye = y.int, y.exp
+            if y.sign == 1:
+                yc = -yc
+
+            # compute correctly rounded result:  start with precision +3,
+            # then increase precision until result is unambiguously roundable
+            extra = 3
+            while True:
+                coeff, exp = _dpower(xc, xe, yc, ye, p+extra)
+                if coeff % (5*10**(len(str(coeff))-p-1)):
+                    break
+                extra += 3
+
+            ans = _dec_from_triple(result_sign, str(coeff), exp)
+
+        # unlike exp, ln and log10, the power function respects the
+        # rounding mode; no need to switch to ROUND_HALF_EVEN here
+
+        # There's a difficulty here when 'other' is not an integer and
+        # the result is exact.  In this case, the specification
+        # requires that the Inexact flag be raised (in spite of
+        # exactness), but since the result is exact _fix won't do this
+        # for us.  (Correspondingly, the Underflow signal should also
+        # be raised for subnormal results.)  We can't directly raise
+        # these signals either before or after calling _fix, since
+        # that would violate the precedence for signals.  So we wrap
+        # the ._fix call in a temporary context, and reraise
+        # afterwards.
+        if exact and not other._isinteger():
+            # pad with zeros up to length context.prec+1 if necessary; this
+            # ensures that the Rounded signal will be raised.
+            if len(ans._int) <= context.prec:
+                expdiff = context.prec + 1 - len(ans._int)
+                ans = _dec_from_triple(ans._sign, ans._int+'0'*expdiff,
+                                       ans._exp-expdiff)
+
+            # create a copy of the current context, with cleared flags/traps
+            newcontext = context.copy()
+            newcontext.clear_flags()
+            for exception in _signals:
+                newcontext.traps[exception] = 0
+
+            # round in the new context
+            ans = ans._fix(newcontext)
+
+            # raise Inexact, and if necessary, Underflow
+            newcontext._raise_error(Inexact)
+            if newcontext.flags[Subnormal]:
+                newcontext._raise_error(Underflow)
+
+            # propagate signals to the original context; _fix could
+            # have raised any of Overflow, Underflow, Subnormal,
+            # Inexact, Rounded, Clamped.  Overflow needs the correct
+            # arguments.  Note that the order of the exceptions is
+            # important here.
+            if newcontext.flags[Overflow]:
+                context._raise_error(Overflow, 'above Emax', ans._sign)
+            for exception in Underflow, Subnormal, Inexact, Rounded, Clamped:
+                if newcontext.flags[exception]:
+                    context._raise_error(exception)
+
+        else:
+            ans = ans._fix(context)
+
+        return ans
+
+    def __rpow__(self, other, context=None):
+        """Swaps self/other and returns __pow__."""
+        other = _convert_other(other)
+        if other is NotImplemented:
+            return other
+        return other.__pow__(self, context=context)
+
+    def normalize(self, context=None):
+        """Normalize- strip trailing 0s, change anything equal to 0 to 0e0"""
+
+        if context is None:
+            context = getcontext()
+
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+
+        dup = self._fix(context)
+        if dup._isinfinity():
+            return dup
+
+        if not dup:
+            return _dec_from_triple(dup._sign, '0', 0)
+        exp_max = [context.Emax, context.Etop()][context.clamp]
+        end = len(dup._int)
+        exp = dup._exp
+        while dup._int[end-1] == '0' and exp < exp_max:
+            exp += 1
+            end -= 1
+        return _dec_from_triple(dup._sign, dup._int[:end], exp)
+
+    def quantize(self, exp, rounding=None, context=None):
+        """Quantize self so its exponent is the same as that of exp.
+
+        Similar to self._rescale(exp._exp) but with error checking.
+        """
+        exp = _convert_other(exp, raiseit=True)
+
+        if context is None:
+            context = getcontext()
+        if rounding is None:
+            rounding = context.rounding
+
+        if self._is_special or exp._is_special:
+            ans = self._check_nans(exp, context)
+            if ans:
+                return ans
+
+            if exp._isinfinity() or self._isinfinity():
+                if exp._isinfinity() and self._isinfinity():
+                    return Decimal(self)  # if both are inf, it is OK
+                return context._raise_error(InvalidOperation,
+                                        'quantize with one INF')
+
+        # exp._exp should be between Etiny and Emax
+        if not (context.Etiny() <= exp._exp <= context.Emax):
+            return context._raise_error(InvalidOperation,
+                   'target exponent out of bounds in quantize')
+
+        if not self:
+            ans = _dec_from_triple(self._sign, '0', exp._exp)
+            return ans._fix(context)
+
+        self_adjusted = self.adjusted()
+        if self_adjusted > context.Emax:
+            return context._raise_error(InvalidOperation,
+                                        'exponent of quantize result too large for current context')
+        if self_adjusted - exp._exp + 1 > context.prec:
+            return context._raise_error(InvalidOperation,
+                                        'quantize result has too many digits for current context')
+
+        ans = self._rescale(exp._exp, rounding)
+        if ans.adjusted() > context.Emax:
+            return context._raise_error(InvalidOperation,
+                                        'exponent of quantize result too large for current context')
+        if len(ans._int) > context.prec:
+            return context._raise_error(InvalidOperation,
+                                        'quantize result has too many digits for current context')
+
+        # raise appropriate flags
+        if ans and ans.adjusted() < context.Emin:
+            context._raise_error(Subnormal)
+        if ans._exp > self._exp:
+            if ans != self:
+                context._raise_error(Inexact)
+            context._raise_error(Rounded)
+
+        # call to fix takes care of any necessary folddown, and
+        # signals Clamped if necessary
+        ans = ans._fix(context)
+        return ans
+
+    def same_quantum(self, other, context=None):
+        """Return True if self and other have the same exponent; otherwise
+        return False.
+
+        If either operand is a special value, the following rules are used:
+           * return True if both operands are infinities
+           * return True if both operands are NaNs
+           * otherwise, return False.
+        """
+        other = _convert_other(other, raiseit=True)
+        if self._is_special or other._is_special:
+            return (self.is_nan() and other.is_nan() or
+                    self.is_infinite() and other.is_infinite())
+        return self._exp == other._exp
+
+    def _rescale(self, exp, rounding):
+        """Rescale self so that the exponent is exp, either by padding with zeros
+        or by truncating digits, using the given rounding mode.
+
+        Specials are returned without change.  This operation is
+        quiet: it raises no flags, and uses no information from the
+        context.
+
+        exp = exp to scale to (an integer)
+        rounding = rounding mode
+        """
+        if self._is_special:
+            return Decimal(self)
+        if not self:
+            return _dec_from_triple(self._sign, '0', exp)
+
+        if self._exp >= exp:
+            # pad answer with zeros if necessary
+            return _dec_from_triple(self._sign,
+                                        self._int + '0'*(self._exp - exp), exp)
+
+        # too many digits; round and lose data.  If self.adjusted() <
+        # exp-1, replace self by 10**(exp-1) before rounding
+        digits = len(self._int) + self._exp - exp
+        if digits < 0:
+            self = _dec_from_triple(self._sign, '1', exp-1)
+            digits = 0
+        this_function = self._pick_rounding_function[rounding]
+        changed = this_function(self, digits)
+        coeff = self._int[:digits] or '0'
+        if changed == 1:
+            coeff = str(int(coeff)+1)
+        return _dec_from_triple(self._sign, coeff, exp)
+
+    def _round(self, places, rounding):
+        """Round a nonzero, nonspecial Decimal to a fixed number of
+        significant figures, using the given rounding mode.
+
+        Infinities, NaNs and zeros are returned unaltered.
+
+        This operation is quiet: it raises no flags, and uses no
+        information from the context.
+
+        """
+        if places <= 0:
+            raise ValueError("argument should be at least 1 in _round")
+        if self._is_special or not self:
+            return Decimal(self)
+        ans = self._rescale(self.adjusted()+1-places, rounding)
+        # it can happen that the rescale alters the adjusted exponent;
+        # for example when rounding 99.97 to 3 significant figures.
+        # When this happens we end up with an extra 0 at the end of
+        # the number; a second rescale fixes this.
+        if ans.adjusted() != self.adjusted():
+            ans = ans._rescale(ans.adjusted()+1-places, rounding)
+        return ans
+
+    def to_integral_exact(self, rounding=None, context=None):
+        """Rounds to a nearby integer.
+
+        If no rounding mode is specified, take the rounding mode from
+        the context.  This method raises the Rounded and Inexact flags
+        when appropriate.
+
+        See also: to_integral_value, which does exactly the same as
+        this method except that it doesn't raise Inexact or Rounded.
+        """
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+            return Decimal(self)
+        if self._exp >= 0:
+            return Decimal(self)
+        if not self:
+            return _dec_from_triple(self._sign, '0', 0)
+        if context is None:
+            context = getcontext()
+        if rounding is None:
+            rounding = context.rounding
+        ans = self._rescale(0, rounding)
+        if ans != self:
+            context._raise_error(Inexact)
+        context._raise_error(Rounded)
+        return ans
+
+    def to_integral_value(self, rounding=None, context=None):
+        """Rounds to the nearest integer, without raising inexact, rounded."""
+        if context is None:
+            context = getcontext()
+        if rounding is None:
+            rounding = context.rounding
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+            return Decimal(self)
+        if self._exp >= 0:
+            return Decimal(self)
+        else:
+            return self._rescale(0, rounding)
+
+    # the method name changed, but we provide also the old one, for compatibility
+    to_integral = to_integral_value
+
+    def sqrt(self, context=None):
+        """Return the square root of self."""
+        if context is None:
+            context = getcontext()
+
+        if self._is_special:
+            ans = self._check_nans(context=context)
+            if ans:
+                return ans
+
+            if self._isinfinity() and self._sign == 0:
+                return Decimal(self)
+
+        if not self:
+            # exponent = self._exp // 2.  sqrt(-0) = -0
+            ans = _dec_from_triple(self._sign, '0', self._exp // 2)
+            return ans._fix(context)
+
+        if self._sign == 1:
+            return context._raise_error(InvalidOperation, 'sqrt(-x), x > 0')
+
+        # At this point self represents a positive number.  Let p be
+        # the desired precision and express self in the form c*100**e
+        # with c a positive real number and e an integer, c and e
+        # being chosen so that 100**(p-1) <= c < 100**p.  Then the
+        # (exact) square root of self is sqrt(c)*10**e, and 10**(p-1)
+        # <= sqrt(c) < 10**p, so the closest representable Decimal at
+        # precision p is n*10**e where n = round_half_even(sqrt(c)),
+        # the closest integer to sqrt(c) with the even integer chosen
+        # in the case of a tie.
+        #
+        # To ensure correct rounding in all cases, we use the
+        # following trick: we compute the square root to an extra
+        # place (precision p+1 instead of precision p), rounding down.
+        # Then, if the result is inexact and its last digit is 0 or 5,
+        # we increase the last digit to 1 or 6 respectively; if it's
+        # exact we leave the last digit alone.  Now the final round to
+        # p places (or fewer in the case of underflow) will round
+        # correctly and raise the appropriate flags.
+
+        # use an extra digit of precision
+        prec = context.prec+1
+
+        # write argument in the form c*100**e where e = self._exp//2
+        # is the 'ideal' exponent, to be used if the square root is
+        # exactly representable.  l is the number of 'digits' of c in
+        # base 100, so that 100**(l-1) <= c < 100**l.
+        op = _WorkRep(self)
+        e = op.exp >> 1
+        if op.exp & 1:
+            c = op.int * 10
+            l = (len(self._int) >> 1) + 1
+        else:
+            c = op.int
+            l = len(self._int)+1 >> 1
+
+        # rescale so that c has exactly prec base 100 'digits'
+        shift = prec-l
+        if shift >= 0:
+            c *= 100**shift
+            exact = True
+        else:
+            c, remainder = divmod(c, 100**-shift)
+            exact = not remainder
+        e -= shift
+
+        # find n = floor(sqrt(c)) using Newton's method
+        n = 10**prec
+        while True:
+            q = c//n
+            if n <= q:
+                break
+            else:
+                n = n + q >> 1
+        exact = exact and n*n == c
+
+        if exact:
+            # result is exact; rescale to use ideal exponent e
+            if shift >= 0:
+                # assert n % 10**shift == 0
+                n //= 10**shift
+            else:
+                n *= 10**-shift
+            e += shift
+        else:
+            # result is not exact; fix last digit as described above
+            if n % 5 == 0:
+                n += 1
+
+        ans = _dec_from_triple(0, str(n), e)
+
+        # round, and fit to current context
+        context = context._shallow_copy()
+        rounding = context._set_rounding(ROUND_HALF_EVEN)
+        ans = ans._fix(context)
+        context.rounding = rounding
+
+        return ans
+
+    def max(self, other, context=None):
+        """Returns the larger value.
+
+        Like max(self, other) except if one is not a number, returns
+        NaN (and signals if one is sNaN).  Also rounds.
+        """
+        other = _convert_other(other, raiseit=True)
+
+        if context is None:
+            context = getcontext()
+
+        if self._is_special or other._is_special:
+            # If one operand is a quiet NaN and the other is number, then the
+            # number is always returned
+            sn = self._isnan()
+            on = other._isnan()
+            if sn or on:
+                if on == 1 and sn == 0:
+                    return self._fix(context)
+                if sn == 1 and on == 0:
+                    return other._fix(context)
+                return self._check_nans(other, context)
+
+        c = self._cmp(other)
+        if c == 0:
+            # If both operands are finite and equal in numerical value
+            # then an ordering is applied:
+            #
+            # If the signs differ then max returns the operand with the
+            # positive sign and min returns the operand with the negative sign
+            #
+            # If the signs are the same then the exponent is used to select
+            # the result.  This is exactly the ordering used in compare_total.
+            c = self.compare_total(other)
+
+        if c == -1:
+            ans = other
+        else:
+            ans = self
+
+        return ans._fix(context)
+
+    def min(self, other, context=None):
+        """Returns the smaller value.
+
+        Like min(self, other) except if one is not a number, returns
+        NaN (and signals if one is sNaN).  Also rounds.
+        """
+        other = _convert_other(other, raiseit=True)
+
+        if context is None:
+            context = getcontext()
+
+        if self._is_special or other._is_special:
+            # If one operand is a quiet NaN and the other is number, then the
+            # number is always returned
+            sn = self._isnan()
+            on = other._isnan()
+            if sn or on:
+                if on == 1 and sn == 0:
+                    return self._fix(context)
+                if sn == 1 and on == 0:
+                    return other._fix(context)
+                return self._check_nans(other, context)
+
+        c = self._cmp(other)
+        if c == 0:
+            c = self.compare_total(other)
+
+        if c == -1:
+            ans = self
+        else:
+            ans = other
+
+        return ans._fix(context)
+
+    def _isinteger(self):
+        """Returns whether self is an integer"""
+        if self._is_special:
+            return False
+        if self._exp >= 0:
+            return True
+        rest = self._int[self._exp:]
+        return rest == '0'*len(rest)
+
+    def _iseven(self):
+        """Returns True if self is even.  Assumes self is an integer."""
+        if not self or self._exp > 0:
+            return True
+        return self._int[-1+self._exp] in '02468'
+
+    def adjusted(self):
+        """Return the adjusted exponent of self"""
+        try:
+            return self._exp + len(self._int) - 1
+        # If NaN or Infinity, self._exp is string
+        except TypeError:
+            return 0
+
+    def canonical(self):
+        """Returns the same Decimal object.
+
+        As we do not have different encodings for the same number, the
+        received object already is in its canonical form.
+        """
+        return self
+
+    def compare_signal(self, other, context=None):
+        """Compares self to the other operand numerically.
+
+        It's pretty much like compare(), but all NaNs signal, with signaling
+        NaNs taking precedence over quiet NaNs.
+        """
+        other = _convert_other(other, raiseit = True)
+        ans = self._compare_check_nans(other, context)
+        if ans:
+            return ans
+        return self.compare(other, context=context)
+
+    def compare_total(self, other, context=None):
+        """Compares self to other using the abstract representations.
+
+        This is not like the standard compare, which use their numerical
+        value. Note that a total ordering is defined for all possible abstract
+        representations.
+        """
+        other = _convert_other(other, raiseit=True)
+
+        # if one is negative and the other is positive, it's easy
+        if self._sign and not other._sign:
+            return _NegativeOne
+        if not self._sign and other._sign:
+            return _One
+        sign = self._sign
+
+        # let's handle both NaN types
+        self_nan = self._isnan()
+        other_nan = other._isnan()
+        if self_nan or other_nan:
+            if self_nan == other_nan:
+                # compare payloads as though they're integers
+                self_key = len(self._int), self._int
+                other_key = len(other._int), other._int
+                if self_key < other_key:
+                    if sign:
+                        return _One
+                    else:
+                        return _NegativeOne
+                if self_key > other_key:
+                    if sign:
+                        return _NegativeOne
+                    else:
+                        return _One
+                return _Zero
+
+            if sign:
+                if self_nan == 1:
+                    return _NegativeOne
+                if other_nan == 1:
+                    return _One
+                if self_nan == 2:
+                    return _NegativeOne
+                if other_nan == 2:
+                    return _One
+            else:
+                if self_nan == 1:
+                    return _One
+                if other_nan == 1:
+                    return _NegativeOne
+                if self_nan == 2:
+                    return _One
+                if other_nan == 2:
+                    return _NegativeOne
+
+        if self < other:
+            return _NegativeOne
+        if self > other:
+            return _One
+
+        if self._exp < other._exp:
+            if sign:
+                return _One
+            else:
+                return _NegativeOne
+        if self._exp > other._exp:
+            if sign:
+                return _NegativeOne
+            else:
+                return _One
+        return _Zero
+
+
+    def compare_total_mag(self, other, context=None):
+        """Compares self to other using abstract repr., ignoring sign.
+
+        Like compare_total, but with operand's sign ignored and assumed to be 0.
+        """
+        other = _convert_other(other, raiseit=True)
+
+        s = self.copy_abs()
+        o = other.copy_abs()
+        return s.compare_total(o)
+
+    def copy_abs(self):
+        """Returns a copy with the sign set to 0. """
+        return _dec_from_triple(0, self._int, self._exp, self._is_special)
+
+    def copy_negate(self):
+        """Returns a copy with the sign inverted."""
+        if self._sign:
+            return _dec_from_triple(0, self._int, self._exp, self._is_special)
+        else:
+            return _dec_from_triple(1, self._int, self._exp, self._is_special)
+
+    def copy_sign(self, other, context=None):
+        """Returns self with the sign of other."""
+        other = _convert_other(other, raiseit=True)
+        return _dec_from_triple(other._sign, self._int,
+                                self._exp, self._is_special)
+
+    def exp(self, context=None):
+        """Returns e ** self."""
+
+        if context is None:
+            context = getcontext()
+
+        # exp(NaN) = NaN
+        ans = self._check_nans(context=context)
+        if ans:
+            return ans
+
+        # exp(-Infinity) = 0
+        if self._isinfinity() == -1:
+            return _Zero
+
+        # exp(0) = 1
+        if not self:
+            return _One
+
+        # exp(Infinity) = Infinity
+        if self._isinfinity() == 1:
+            return Decimal(self)
+
+        # the result is now guaranteed to be inexact (the true
+        # mathematical result is transcendental). There's no need to
+        # raise Rounded and Inexact here---they'll always be raised as
+        # a result of the call to _fix.
+        p = context.prec
+        adj = self.adjusted()
+
+        # we only need to do any computation for quite a small range
+        # of adjusted exponents---for example, -29 <= adj <= 10 for
+        # the default context.  For smaller exponent the result is
+        # indistinguishable from 1 at the given precision, while for
+        # larger exponent the result either overflows or underflows.
+        if self._sign == 0 and adj > len(str((context.Emax+1)*3)):
+            # overflow
+            ans = _dec_from_triple(0, '1', context.Emax+1)
+        elif self._sign == 1 and adj > len(str((-context.Etiny()+1)*3)):
+            # underflow to 0
+            ans = _dec_from_triple(0, '1', context.Etiny()-1)
+        elif self._sign == 0 and adj < -p:
+            # p+1 digits; final round will raise correct flags
+            ans = _dec_from_triple(0, '1' + '0'*(p-1) + '1', -p)
+        elif self._sign == 1 and adj < -p-1:
+            # p+1 digits; final round will raise correct flags
+            ans = _dec_from_triple(0, '9'*(p+1), -p-1)
+        # general case
+        else:
+            op = _WorkRep(self)
+            c, e = op.int, op.exp
+            if op.sign == 1:
+                c = -c
+
+            # compute correctly rounded result: increase precision by
+            # 3 digits at a time until we get an unambiguously
+            # roundable result
+            extra = 3
+            while True:
+                coeff, exp = _dexp(c, e, p+extra)
+                if coeff % (5*10**(len(str(coeff))-p-1)):
+                    break
+                extra += 3
+
+            ans = _dec_from_triple(0, str(coeff), exp)
+
+        # at this stage, ans should round correctly with *any*
+        # rounding mode, not just with ROUND_HALF_EVEN
+        context = context._shallow_copy()
+        rounding = context._set_rounding(ROUND_HALF_EVEN)
+        ans = ans._fix(context)
+        context.rounding = rounding
+
+        return ans
+
+    def is_canonical(self):
+        """Return True if self is canonical; otherwise return False.
+
+        Currently, the encoding of a Decimal instance is always
+        canonical, so this method returns True for any Decimal.
+        """
+        return True
+
+    def is_finite(self):
+        """Return True if self is finite; otherwise return False.
+
+        A Decimal instance is considered finite if it is neither
+        infinite nor a NaN.
+        """
+        return not self._is_special
+
+    def is_infinite(self):
+        """Return True if self is infinite; otherwise return False."""
+        return self._exp == 'F'
+
+    def is_nan(self):
+        """Return True if self is a qNaN or sNaN; otherwise return False."""
+        return self._exp in ('n', 'N')
+
+    def is_normal(self, context=None):
+        """Return True if self is a normal number; otherwise return False."""
+        if self._is_special or not self:
+            return False
+        if context is None:
+            context = getcontext()
+        return context.Emin <= self.adjusted()
+
+    def is_qnan(self):
+        """Return True if self is a quiet NaN; otherwise return False."""
+        return self._exp == 'n'
+
+    def is_signed(self):
+        """Return True if self is negative; otherwise return False."""
+        return self._sign == 1
+
+    def is_snan(self):
+        """Return True if self is a signaling NaN; otherwise return False."""
+        return self._exp == 'N'
+
+    def is_subnormal(self, context=None):
+        """Return True if self is subnormal; otherwise return False."""
+        if self._is_special or not self:
+            return False
+        if context is None:
+            context = getcontext()
+        return self.adjusted() < context.Emin
+
+    def is_zero(self):
+        """Return True if self is a zero; otherwise return False."""
+        return not self._is_special and self._int == '0'
+
+    def _ln_exp_bound(self):
+        """Compute a lower bound for the adjusted exponent of self.ln().
+        In other words, compute r such that self.ln() >= 10**r.  Assumes
+        that self is finite and positive and that self != 1.
+        """
+
+        # for 0.1 <= x <= 10 we use the inequalities 1-1/x <= ln(x) <= x-1
+        adj = self._exp + len(self._int) - 1
+        if adj >= 1:
+            # argument >= 10; we use 23/10 = 2.3 as a lower bound for ln(10)
+            return len(str(adj*23//10)) - 1
+        if adj <= -2:
+            # argument <= 0.1
+            return len(str((-1-adj)*23//10)) - 1
+        op = _WorkRep(self)
+        c, e = op.int, op.exp
+        if adj == 0:
+            # 1 < self < 10
+            num = str(c-10**-e)
+            den = str(c)
+            return len(num) - len(den) - (num < den)
+        # adj == -1, 0.1 <= self < 1
+        return e + len(str(10**-e - c)) - 1
+
+
+    def ln(self, context=None):
+        """Returns the natural (base e) logarithm of self."""
+
+        if context is None:
+            context = getcontext()
+
+        # ln(NaN) = NaN
+        ans = self._check_nans(context=context)
+        if ans:
+            return ans
+
+        # ln(0.0) == -Infinity
+        if not self:
+            return _NegativeInfinity
+
+        # ln(Infinity) = Infinity
+        if self._isinfinity() == 1:
+            return _Infinity
+
+        # ln(1.0) == 0.0
+        if self == _One:
+            return _Zero
+
+        # ln(negative) raises InvalidOperation
+        if self._sign == 1:
+            return context._raise_error(InvalidOperation,
+                                        'ln of a negative value')
+
+        # result is irrational, so necessarily inexact
+        op = _WorkRep(self)
+        c, e = op.int, op.exp
+        p = context.prec
+
+        # correctly rounded result: repeatedly increase precision by 3
+        # until we get an unambiguously roundable result
+        places = p - self._ln_exp_bound() + 2 # at least p+3 places
+        while True:
+            coeff = _dlog(c, e, places)
+            # assert len(str(abs(coeff)))-p >= 1
+            if coeff % (5*10**(len(str(abs(coeff)))-p-1)):
+                break
+            places += 3
+        ans = _dec_from_triple(int(coeff<0), str(abs(coeff)), -places)
+
+        context = context._shallow_copy()
+        rounding = context._set_rounding(ROUND_HALF_EVEN)
+        ans = ans._fix(context)
+        context.rounding = rounding
+        return ans
+
+    def _log10_exp_bound(self):
+        """Compute a lower bound for the adjusted exponent of self.log10().
+        In other words, find r such that self.log10() >= 10**r.
+        Assumes that self is finite and positive and that self != 1.
+        """
+
+        # For x >= 10 or x < 0.1 we only need a bound on the integer
+        # part of log10(self), and this comes directly from the
+        # exponent of x.  For 0.1 <= x <= 10 we use the inequalities
+        # 1-1/x <= log(x) <= x-1. If x > 1 we have |log10(x)| >
+        # (1-1/x)/2.31 > 0.  If x < 1 then |log10(x)| > (1-x)/2.31 > 0
+
+        adj = self._exp + len(self._int) - 1
+        if adj >= 1:
+            # self >= 10
+            return len(str(adj))-1
+        if adj <= -2:
+            # self < 0.1
+            return len(str(-1-adj))-1
+        op = _WorkRep(self)
+        c, e = op.int, op.exp
+        if adj == 0:
+            # 1 < self < 10
+            num = str(c-10**-e)
+            den = str(231*c)
+            return len(num) - len(den) - (num < den) + 2
+        # adj == -1, 0.1 <= self < 1
+        num = str(10**-e-c)
+        return len(num) + e - (num < "231") - 1
+
+    def log10(self, context=None):
+        """Returns the base 10 logarithm of self."""
+
+        if context is None:
+            context = getcontext()
+
+        # log10(NaN) = NaN
+        ans = self._check_nans(context=context)
+        if ans:
+            return ans
+
+        # log10(0.0) == -Infinity
+        if not self:
+            return _NegativeInfinity
+
+        # log10(Infinity) = Infinity
+        if self._isinfinity() == 1:
+            return _Infinity
+
+        # log10(negative or -Infinity) raises InvalidOperation
+        if self._sign == 1:
+            return context._raise_error(InvalidOperation,
+                                        'log10 of a negative value')
+
+        # log10(10**n) = n
+        if self._int[0] == '1' and self._int[1:] == '0'*(len(self._int) - 1):
+            # answer may need rounding
+            ans = Decimal(self._exp + len(self._int) - 1)
+        else:
+            # result is irrational, so necessarily inexact
+            op = _WorkRep(self)
+            c, e = op.int, op.exp
+            p = context.prec
+
+            # correctly rounded result: repeatedly increase precision
+            # until result is unambiguously roundable
+            places = p-self._log10_exp_bound()+2
+            while True:
+                coeff = _dlog10(c, e, places)
+                # assert len(str(abs(coeff)))-p >= 1
+                if coeff % (5*10**(len(str(abs(coeff)))-p-1)):
+                    break
+                places += 3
+            ans = _dec_from_triple(int(coeff<0), str(abs(coeff)), -places)
+
+        context = context._shallow_copy()
+        rounding = context._set_rounding(ROUND_HALF_EVEN)
+        ans = ans._fix(context)
+        context.rounding = rounding
+        return ans
+
+    def logb(self, context=None):
+        """ Returns the exponent of the magnitude of self's MSD.
+
+        The result is the integer which is the exponent of the magnitude
+        of the most significant digit of self (as though it were truncated
+        to a single digit while maintaining the value of that digit and
+        without limiting the resulting exponent).
+        """
+        # logb(NaN) = NaN
+        ans = self._check_nans(context=context)
+        if ans:
+            return ans
+
+        if context is None:
+            context = getcontext()
+
+        # logb(+/-Inf) = +Inf
+        if self._isinfinity():
+            return _Infinity
+
+        # logb(0) = -Inf, DivisionByZero
+        if not self:
+            return context._raise_error(DivisionByZero, 'logb(0)', 1)
+
+        # otherwise, simply return the adjusted exponent of self, as a
+        # Decimal.  Note that no attempt is made to fit the result
+        # into the current context.
+        ans = Decimal(self.adjusted())
+        return ans._fix(context)
+
+    def _islogical(self):
+        """Return True if self is a logical operand.
+
+        For being logical, it must be a finite number with a sign of 0,
+        an exponent of 0, and a coefficient whose digits must all be
+        either 0 or 1.
+        """
+        if self._sign != 0 or self._exp != 0:
+            return False
+        for dig in self._int:
+            if dig not in '01':
+                return False
+        return True
+
+    def _fill_logical(self, context, opa, opb):
+        dif = context.prec - len(opa)
+        if dif > 0:
+            opa = '0'*dif + opa
+        elif dif < 0:
+            opa = opa[-context.prec:]
+        dif = context.prec - len(opb)
+        if dif > 0:
+            opb = '0'*dif + opb
+        elif dif < 0:
+            opb = opb[-context.prec:]
+        return opa, opb
+
+    def logical_and(self, other, context=None):
+        """Applies an 'and' operation between self and other's digits."""
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        if not self._islogical() or not other._islogical():
+            return context._raise_error(InvalidOperation)
+
+        # fill to context.prec
+        (opa, opb) = self._fill_logical(context, self._int, other._int)
+
+        # make the operation, and clean starting zeroes
+        result = "".join([str(int(a)&int(b)) for a,b in zip(opa,opb)])
+        return _dec_from_triple(0, result.lstrip('0') or '0', 0)
+
+    def logical_invert(self, context=None):
+        """Invert all its digits."""
+        if context is None:
+            context = getcontext()
+        return self.logical_xor(_dec_from_triple(0,'1'*context.prec,0),
+                                context)
+
+    def logical_or(self, other, context=None):
+        """Applies an 'or' operation between self and other's digits."""
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        if not self._islogical() or not other._islogical():
+            return context._raise_error(InvalidOperation)
+
+        # fill to context.prec
+        (opa, opb) = self._fill_logical(context, self._int, other._int)
+
+        # make the operation, and clean starting zeroes
+        result = "".join([str(int(a)|int(b)) for a,b in zip(opa,opb)])
+        return _dec_from_triple(0, result.lstrip('0') or '0', 0)
+
+    def logical_xor(self, other, context=None):
+        """Applies an 'xor' operation between self and other's digits."""
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        if not self._islogical() or not other._islogical():
+            return context._raise_error(InvalidOperation)
+
+        # fill to context.prec
+        (opa, opb) = self._fill_logical(context, self._int, other._int)
+
+        # make the operation, and clean starting zeroes
+        result = "".join([str(int(a)^int(b)) for a,b in zip(opa,opb)])
+        return _dec_from_triple(0, result.lstrip('0') or '0', 0)
+
+    def max_mag(self, other, context=None):
+        """Compares the values numerically with their sign ignored."""
+        other = _convert_other(other, raiseit=True)
+
+        if context is None:
+            context = getcontext()
+
+        if self._is_special or other._is_special:
+            # If one operand is a quiet NaN and the other is number, then the
+            # number is always returned
+            sn = self._isnan()
+            on = other._isnan()
+            if sn or on:
+                if on == 1 and sn == 0:
+                    return self._fix(context)
+                if sn == 1 and on == 0:
+                    return other._fix(context)
+                return self._check_nans(other, context)
+
+        c = self.copy_abs()._cmp(other.copy_abs())
+        if c == 0:
+            c = self.compare_total(other)
+
+        if c == -1:
+            ans = other
+        else:
+            ans = self
+
+        return ans._fix(context)
+
+    def min_mag(self, other, context=None):
+        """Compares the values numerically with their sign ignored."""
+        other = _convert_other(other, raiseit=True)
+
+        if context is None:
+            context = getcontext()
+
+        if self._is_special or other._is_special:
+            # If one operand is a quiet NaN and the other is number, then the
+            # number is always returned
+            sn = self._isnan()
+            on = other._isnan()
+            if sn or on:
+                if on == 1 and sn == 0:
+                    return self._fix(context)
+                if sn == 1 and on == 0:
+                    return other._fix(context)
+                return self._check_nans(other, context)
+
+        c = self.copy_abs()._cmp(other.copy_abs())
+        if c == 0:
+            c = self.compare_total(other)
+
+        if c == -1:
+            ans = self
+        else:
+            ans = other
+
+        return ans._fix(context)
+
+    def next_minus(self, context=None):
+        """Returns the largest representable number smaller than itself."""
+        if context is None:
+            context = getcontext()
+
+        ans = self._check_nans(context=context)
+        if ans:
+            return ans
+
+        if self._isinfinity() == -1:
+            return _NegativeInfinity
+        if self._isinfinity() == 1:
+            return _dec_from_triple(0, '9'*context.prec, context.Etop())
+
+        context = context.copy()
+        context._set_rounding(ROUND_FLOOR)
+        context._ignore_all_flags()
+        new_self = self._fix(context)
+        if new_self != self:
+            return new_self
+        return self.__sub__(_dec_from_triple(0, '1', context.Etiny()-1),
+                            context)
+
+    def next_plus(self, context=None):
+        """Returns the smallest representable number larger than itself."""
+        if context is None:
+            context = getcontext()
+
+        ans = self._check_nans(context=context)
+        if ans:
+            return ans
+
+        if self._isinfinity() == 1:
+            return _Infinity
+        if self._isinfinity() == -1:
+            return _dec_from_triple(1, '9'*context.prec, context.Etop())
+
+        context = context.copy()
+        context._set_rounding(ROUND_CEILING)
+        context._ignore_all_flags()
+        new_self = self._fix(context)
+        if new_self != self:
+            return new_self
+        return self.__add__(_dec_from_triple(0, '1', context.Etiny()-1),
+                            context)
+
+    def next_toward(self, other, context=None):
+        """Returns the number closest to self, in the direction towards other.
+
+        The result is the closest representable number to self
+        (excluding self) that is in the direction towards other,
+        unless both have the same value.  If the two operands are
+        numerically equal, then the result is a copy of self with the
+        sign set to be the same as the sign of other.
+        """
+        other = _convert_other(other, raiseit=True)
+
+        if context is None:
+            context = getcontext()
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        comparison = self._cmp(other)
+        if comparison == 0:
+            return self.copy_sign(other)
+
+        if comparison == -1:
+            ans = self.next_plus(context)
+        else: # comparison == 1
+            ans = self.next_minus(context)
+
+        # decide which flags to raise using value of ans
+        if ans._isinfinity():
+            context._raise_error(Overflow,
+                                 'Infinite result from next_toward',
+                                 ans._sign)
+            context._raise_error(Inexact)
+            context._raise_error(Rounded)
+        elif ans.adjusted() < context.Emin:
+            context._raise_error(Underflow)
+            context._raise_error(Subnormal)
+            context._raise_error(Inexact)
+            context._raise_error(Rounded)
+            # if precision == 1 then we don't raise Clamped for a
+            # result 0E-Etiny.
+            if not ans:
+                context._raise_error(Clamped)
+
+        return ans
+
+    def number_class(self, context=None):
+        """Returns an indication of the class of self.
+
+        The class is one of the following strings:
+          sNaN
+          NaN
+          -Infinity
+          -Normal
+          -Subnormal
+          -Zero
+          +Zero
+          +Subnormal
+          +Normal
+          +Infinity
+        """
+        if self.is_snan():
+            return "sNaN"
+        if self.is_qnan():
+            return "NaN"
+        inf = self._isinfinity()
+        if inf == 1:
+            return "+Infinity"
+        if inf == -1:
+            return "-Infinity"
+        if self.is_zero():
+            if self._sign:
+                return "-Zero"
+            else:
+                return "+Zero"
+        if context is None:
+            context = getcontext()
+        if self.is_subnormal(context=context):
+            if self._sign:
+                return "-Subnormal"
+            else:
+                return "+Subnormal"
+        # just a normal, regular, boring number, :)
+        if self._sign:
+            return "-Normal"
+        else:
+            return "+Normal"
+
+    def radix(self):
+        """Just returns 10, as this is Decimal, :)"""
+        return Decimal(10)
+
+    def rotate(self, other, context=None):
+        """Returns a rotated copy of self, value-of-other times."""
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        if other._exp != 0:
+            return context._raise_error(InvalidOperation)
+        if not (-context.prec <= int(other) <= context.prec):
+            return context._raise_error(InvalidOperation)
+
+        if self._isinfinity():
+            return Decimal(self)
+
+        # get values, pad if necessary
+        torot = int(other)
+        rotdig = self._int
+        topad = context.prec - len(rotdig)
+        if topad > 0:
+            rotdig = '0'*topad + rotdig
+        elif topad < 0:
+            rotdig = rotdig[-topad:]
+
+        # let's rotate!
+        rotated = rotdig[torot:] + rotdig[:torot]
+        return _dec_from_triple(self._sign,
+                                rotated.lstrip('0') or '0', self._exp)
+
+    def scaleb(self, other, context=None):
+        """Returns self operand after adding the second value to its exp."""
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        if other._exp != 0:
+            return context._raise_error(InvalidOperation)
+        liminf = -2 * (context.Emax + context.prec)
+        limsup =  2 * (context.Emax + context.prec)
+        if not (liminf <= int(other) <= limsup):
+            return context._raise_error(InvalidOperation)
+
+        if self._isinfinity():
+            return Decimal(self)
+
+        d = _dec_from_triple(self._sign, self._int, self._exp + int(other))
+        d = d._fix(context)
+        return d
+
+    def shift(self, other, context=None):
+        """Returns a shifted copy of self, value-of-other times."""
+        if context is None:
+            context = getcontext()
+
+        other = _convert_other(other, raiseit=True)
+
+        ans = self._check_nans(other, context)
+        if ans:
+            return ans
+
+        if other._exp != 0:
+            return context._raise_error(InvalidOperation)
+        if not (-context.prec <= int(other) <= context.prec):
+            return context._raise_error(InvalidOperation)
+
+        if self._isinfinity():
+            return Decimal(self)
+
+        # get values, pad if necessary
+        torot = int(other)
+        rotdig = self._int
+        topad = context.prec - len(rotdig)
+        if topad > 0:
+            rotdig = '0'*topad + rotdig
+        elif topad < 0:
+            rotdig = rotdig[-topad:]
+
+        # let's shift!
+        if torot < 0:
+            shifted = rotdig[:torot]
+        else:
+            shifted = rotdig + '0'*torot
+            shifted = shifted[-context.prec:]
+
+        return _dec_from_triple(self._sign,
+                                    shifted.lstrip('0') or '0', self._exp)
+
+    # Support for pickling, copy, and deepcopy
+    def __reduce__(self):
+        return (self.__class__, (str(self),))
+
+    def __copy__(self):
+        if type(self) is Decimal:
+            return self     # I'm immutable; therefore I am my own clone
+        return self.__class__(str(self))
+
+    def __deepcopy__(self, memo):
+        if type(self) is Decimal:
+            return self     # My components are also immutable
+        return self.__class__(str(self))
+
+    # PEP 3101 support.  the _localeconv keyword argument should be
+    # considered private: it's provided for ease of testing only.
+    def __format__(self, specifier, context=None, _localeconv=None):
+        """Format a Decimal instance according to the given specifier.
+
+        The specifier should be a standard format specifier, with the
+        form described in PEP 3101.  Formatting types 'e', 'E', 'f',
+        'F', 'g', 'G', 'n' and '%' are supported.  If the formatting
+        type is omitted it defaults to 'g' or 'G', depending on the
+        value of context.capitals.
+        """
+
+        # Note: PEP 3101 says that if the type is not present then
+        # there should be at least one digit after the decimal point.
+        # We take the liberty of ignoring this requirement for
+        # Decimal---it's presumably there to make sure that
+        # format(float, '') behaves similarly to str(float).
+        if context is None:
+            context = getcontext()
+
+        spec = _parse_format_specifier(specifier, _localeconv=_localeconv)
+
+        # special values don't care about the type or precision
+        if self._is_special:
+            sign = _format_sign(self._sign, spec)
+            body = str(self.copy_abs())
+            if spec['type'] == '%':
+                body += '%'
+            return _format_align(sign, body, spec)
+
+        # a type of None defaults to 'g' or 'G', depending on context
+        if spec['type'] is None:
+            spec['type'] = ['g', 'G'][context.capitals]
+
+        # if type is '%', adjust exponent of self accordingly
+        if spec['type'] == '%':
+            self = _dec_from_triple(self._sign, self._int, self._exp+2)
+
+        # round if necessary, taking rounding mode from the context
+        rounding = context.rounding
+        precision = spec['precision']
+        if precision is not None:
+            if spec['type'] in 'eE':
+                self = self._round(precision+1, rounding)
+            elif spec['type'] in 'fF%':
+                self = self._rescale(-precision, rounding)
+            elif spec['type'] in 'gG' and len(self._int) > precision:
+                self = self._round(precision, rounding)
+        # special case: zeros with a positive exponent can't be
+        # represented in fixed point; rescale them to 0e0.
+        if not self and self._exp > 0 and spec['type'] in 'fF%':
+            self = self._rescale(0, rounding)
+
+        # figure out placement of the decimal point
+        leftdigits = self._exp + len(self._int)
+        if spec['type'] in 'eE':
+            if not self and precision is not None:
+                dotplace = 1 - precision
+            else:
+                dotplace = 1
+        elif spec['type'] in 'fF%':
+            dotplace = leftdigits
+        elif spec['type'] in 'gG':
+            if self._exp <= 0 and leftdigits > -6:
+                dotplace = leftdigits
+            else:
+                dotplace = 1
+
+        # find digits before and after decimal point, and get exponent
+        if dotplace < 0:
+            intpart = '0'
+            fracpart = '0'*(-dotplace) + self._int
+        elif dotplace > len(self._int):
+            intpart = self._int + '0'*(dotplace-len(self._int))
+            fracpart = ''
+        else:
+            intpart = self._int[:dotplace] or '0'
+            fracpart = self._int[dotplace:]
+        exp = leftdigits-dotplace
+
+        # done with the decimal-specific stuff;  hand over the rest
+        # of the formatting to the _format_number function
+        return _format_number(self._sign, intpart, fracpart, exp, spec)
+
+def _dec_from_triple(sign, coefficient, exponent, special=False):
+    """Create a decimal instance directly, without any validation,
+    normalization (e.g. removal of leading zeros) or argument
+    conversion.
+
+    This function is for *internal use only*.
+    """
+
+    self = object.__new__(Decimal)
+    self._sign = sign
+    self._int = coefficient
+    self._exp = exponent
+    self._is_special = special
+
+    return self
+
+# Register Decimal as a kind of Number (an abstract base class).
+# However, do not register it as Real (because Decimals are not
+# interoperable with floats).
+_numbers.Number.register(Decimal)
+
+
+##### Context class #######################################################
+
+class _ContextManager(object):
+    """Context manager class to support localcontext().
+
+      Sets a copy of the supplied context in __enter__() and restores
+      the previous decimal context in __exit__()
+    """
+    def __init__(self, new_context):
+        self.new_context = new_context.copy()
+    def __enter__(self):
+        self.saved_context = getcontext()
+        setcontext(self.new_context)
+        return self.new_context
+    def __exit__(self, t, v, tb):
+        setcontext(self.saved_context)
+
+class Context(object):
+    """Contains the context for a Decimal instance.
+
+    Contains:
+    prec - precision (for use in rounding, division, square roots..)
+    rounding - rounding type (how you round)
+    traps - If traps[exception] = 1, then the exception is
+                    raised when it is caused.  Otherwise, a value is
+                    substituted in.
+    flags  - When an exception is caused, flags[exception] is set.
+             (Whether or not the trap_enabler is set)
+             Should be reset by user of Decimal instance.
+    Emin -   Minimum exponent
+    Emax -   Maximum exponent
+    capitals -      If 1, 1*10^1 is printed as 1E+1.
+                    If 0, printed as 1e1
+    clamp -  If 1, change exponents if too high (Default 0)
+    """
+
+    def __init__(self, prec=None, rounding=None, Emin=None, Emax=None,
+                       capitals=None, clamp=None, flags=None, traps=None,
+                       _ignored_flags=None):
+        # Set defaults; for everything except flags and _ignored_flags,
+        # inherit from DefaultContext.
+        try:
+            dc = DefaultContext
+        except NameError:
+            pass
+
+        self.prec = prec if prec is not None else dc.prec
+        self.rounding = rounding if rounding is not None else dc.rounding
+        self.Emin = Emin if Emin is not None else dc.Emin
+        self.Emax = Emax if Emax is not None else dc.Emax
+        self.capitals = capitals if capitals is not None else dc.capitals
+        self.clamp = clamp if clamp is not None else dc.clamp
+
+        if _ignored_flags is None:
+            self._ignored_flags = []
+        else:
+            self._ignored_flags = _ignored_flags
+
+        if traps is None:
+            self.traps = dc.traps.copy()
+        elif not isinstance(traps, dict):
+            self.traps = dict((s, int(s in traps)) for s in _signals + traps)
+        else:
+            self.traps = traps
+
+        if flags is None:
+            self.flags = dict.fromkeys(_signals, 0)
+        elif not isinstance(flags, dict):
+            self.flags = dict((s, int(s in flags)) for s in _signals + flags)
+        else:
+            self.flags = flags
+
+    def _set_integer_check(self, name, value, vmin, vmax):
+        if not isinstance(value, int):
+            raise TypeError("%s must be an integer" % name)
+        if vmin == '-inf':
+            if value > vmax:
+                raise ValueError("%s must be in [%s, %d]. got: %s" % (name, vmin, vmax, value))
+        elif vmax == 'inf':
+            if value < vmin:
+                raise ValueError("%s must be in [%d, %s]. got: %s" % (name, vmin, vmax, value))
+        else:
+            if value < vmin or value > vmax:
+                raise ValueError("%s must be in [%d, %d]. got %s" % (name, vmin, vmax, value))
+        return object.__setattr__(self, name, value)
+
+    def _set_signal_dict(self, name, d):
+        if not isinstance(d, dict):
+            raise TypeError("%s must be a signal dict" % d)
+        for key in d:
+            if not key in _signals:
+                raise KeyError("%s is not a valid signal dict" % d)
+        for key in _signals:
+            if not key in d:
+                raise KeyError("%s is not a valid signal dict" % d)
+        return object.__setattr__(self, name, d)
+
+    def __setattr__(self, name, value):
+        if name == 'prec':
+            return self._set_integer_check(name, value, 1, 'inf')
+        elif name == 'Emin':
+            return self._set_integer_check(name, value, '-inf', 0)
+        elif name == 'Emax':
+            return self._set_integer_check(name, value, 0, 'inf')
+        elif name == 'capitals':
+            return self._set_integer_check(name, value, 0, 1)
+        elif name == 'clamp':
+            return self._set_integer_check(name, value, 0, 1)
+        elif name == 'rounding':
+            if not value in _rounding_modes:
+                # raise TypeError even for strings to have consistency
+                # among various implementations.
+                raise TypeError("%s: invalid rounding mode" % value)
+            return object.__setattr__(self, name, value)
+        elif name == 'flags' or name == 'traps':
+            return self._set_signal_dict(name, value)
+        elif name == '_ignored_flags':
+            return object.__setattr__(self, name, value)
+        else:
+            raise AttributeError(
+                "'decimal.Context' object has no attribute '%s'" % name)
+
+    def __delattr__(self, name):
+        raise AttributeError("%s cannot be deleted" % name)
+
+    # Support for pickling, copy, and deepcopy
+    def __reduce__(self):
+        flags = [sig for sig, v in self.flags.items() if v]
+        traps = [sig for sig, v in self.traps.items() if v]
+        return (self.__class__,
+                (self.prec, self.rounding, self.Emin, self.Emax,
+                 self.capitals, self.clamp, flags, traps))
+
+    def __repr__(self):
+        """Show the current context."""
+        s = []
+        s.append('Context(prec=%(prec)d, rounding=%(rounding)s, '
+                 'Emin=%(Emin)d, Emax=%(Emax)d, capitals=%(capitals)d, '
+                 'clamp=%(clamp)d'
+                 % vars(self))
+        names = [f.__name__ for f, v in self.flags.items() if v]
+        s.append('flags=[' + ', '.join(names) + ']')
+        names = [t.__name__ for t, v in self.traps.items() if v]
+        s.append('traps=[' + ', '.join(names) + ']')
+        return ', '.join(s) + ')'
+
+    def clear_flags(self):
+        """Reset all flags to zero"""
+        for flag in self.flags:
+            self.flags[flag] = 0
+
+    def clear_traps(self):
+        """Reset all traps to zero"""
+        for flag in self.traps:
+            self.traps[flag] = 0
+
+    def _shallow_copy(self):
+        """Returns a shallow copy from self."""
+        nc = Context(self.prec, self.rounding, self.Emin, self.Emax,
+                     self.capitals, self.clamp, self.flags, self.traps,
+                     self._ignored_flags)
+        return nc
+
+    def copy(self):
+        """Returns a deep copy from self."""
+        nc = Context(self.prec, self.rounding, self.Emin, self.Emax,
+                     self.capitals, self.clamp,
+                     self.flags.copy(), self.traps.copy(),
+                     self._ignored_flags)
+        return nc
+    __copy__ = copy
+
+    def _raise_error(self, condition, explanation = None, *args):
+        """Handles an error
+
+        If the flag is in _ignored_flags, returns the default response.
+        Otherwise, it sets the flag, then, if the corresponding
+        trap_enabler is set, it reraises the exception.  Otherwise, it returns
+        the default value after setting the flag.
+        """
+        error = _condition_map.get(condition, condition)
+        if error in self._ignored_flags:
+            # Don't touch the flag
+            return error().handle(self, *args)
+
+        self.flags[error] = 1
+        if not self.traps[error]:
+            # The errors define how to handle themselves.
+            return condition().handle(self, *args)
+
+        # Errors should only be risked on copies of the context
+        # self._ignored_flags = []
+        raise error(explanation)
+
+    def _ignore_all_flags(self):
+        """Ignore all flags, if they are raised"""
+        return self._ignore_flags(*_signals)
+
+    def _ignore_flags(self, *flags):
+        """Ignore the flags, if they are raised"""
+        # Do not mutate-- This way, copies of a context leave the original
+        # alone.
+        self._ignored_flags = (self._ignored_flags + list(flags))
+        return list(flags)
+
+    def _regard_flags(self, *flags):
+        """Stop ignoring the flags, if they are raised"""
+        if flags and isinstance(flags[0], (tuple,list)):
+            flags = flags[0]
+        for flag in flags:
+            self._ignored_flags.remove(flag)
+
+    # We inherit object.__hash__, so we must deny this explicitly
+    __hash__ = None
+
+    def Etiny(self):
+        """Returns Etiny (= Emin - prec + 1)"""
+        return int(self.Emin - self.prec + 1)
+
+    def Etop(self):
+        """Returns maximum exponent (= Emax - prec + 1)"""
+        return int(self.Emax - self.prec + 1)
+
+    def _set_rounding(self, type):
+        """Sets the rounding type.
+
+        Sets the rounding type, and returns the current (previous)
+        rounding type.  Often used like:
+
+        context = context.copy()
+        # so you don't change the calling context
+        # if an error occurs in the middle.
+        rounding = context._set_rounding(ROUND_UP)
+        val = self.__sub__(other, context=context)
+        context._set_rounding(rounding)
+
+        This will make it round up for that operation.
+        """
+        rounding = self.rounding
+        self.rounding= type
+        return rounding
+
+    def create_decimal(self, num='0'):
+        """Creates a new Decimal instance but using self as context.
+
+        This method implements the to-number operation of the
+        IBM Decimal specification."""
+
+        if isinstance(num, str) and num != num.strip():
+            return self._raise_error(ConversionSyntax,
+                                     "no trailing or leading whitespace is "
+                                     "permitted.")
+
+        d = Decimal(num, context=self)
+        if d._isnan() and len(d._int) > self.prec - self.clamp:
+            return self._raise_error(ConversionSyntax,
+                                     "diagnostic info too long in NaN")
+        return d._fix(self)
+
+    def create_decimal_from_float(self, f):
+        """Creates a new Decimal instance from a float but rounding using self
+        as the context.
+
+        >>> context = Context(prec=5, rounding=ROUND_DOWN)
+        >>> context.create_decimal_from_float(3.1415926535897932)
+        Decimal('3.1415')
+        >>> context = Context(prec=5, traps=[Inexact])
+        >>> context.create_decimal_from_float(3.1415926535897932)
+        Traceback (most recent call last):
+            ...
+        decimal.Inexact
+
+        """
+        d = Decimal.from_float(f)       # An exact conversion
+        return d._fix(self)             # Apply the context rounding
+
+    # Methods
+    def abs(self, a):
+        """Returns the absolute value of the operand.
+
+        If the operand is negative, the result is the same as using the minus
+        operation on the operand.  Otherwise, the result is the same as using
+        the plus operation on the operand.
+
+        >>> ExtendedContext.abs(Decimal('2.1'))
+        Decimal('2.1')
+        >>> ExtendedContext.abs(Decimal('-100'))
+        Decimal('100')
+        >>> ExtendedContext.abs(Decimal('101.5'))
+        Decimal('101.5')
+        >>> ExtendedContext.abs(Decimal('-101.5'))
+        Decimal('101.5')
+        >>> ExtendedContext.abs(-1)
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.__abs__(context=self)
+
+    def add(self, a, b):
+        """Return the sum of the two operands.
+
+        >>> ExtendedContext.add(Decimal('12'), Decimal('7.00'))
+        Decimal('19.00')
+        >>> ExtendedContext.add(Decimal('1E+2'), Decimal('1.01E+4'))
+        Decimal('1.02E+4')
+        >>> ExtendedContext.add(1, Decimal(2))
+        Decimal('3')
+        >>> ExtendedContext.add(Decimal(8), 5)
+        Decimal('13')
+        >>> ExtendedContext.add(5, 5)
+        Decimal('10')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__add__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def _apply(self, a):
+        return str(a._fix(self))
+
+    def canonical(self, a):
+        """Returns the same Decimal object.
+
+        As we do not have different encodings for the same number, the
+        received object already is in its canonical form.
+
+        >>> ExtendedContext.canonical(Decimal('2.50'))
+        Decimal('2.50')
+        """
+        if not isinstance(a, Decimal):
+            raise TypeError("canonical requires a Decimal as an argument.")
+        return a.canonical()
+
+    def compare(self, a, b):
+        """Compares values numerically.
+
+        If the signs of the operands differ, a value representing each operand
+        ('-1' if the operand is less than zero, '0' if the operand is zero or
+        negative zero, or '1' if the operand is greater than zero) is used in
+        place of that operand for the comparison instead of the actual
+        operand.
+
+        The comparison is then effected by subtracting the second operand from
+        the first and then returning a value according to the result of the
+        subtraction: '-1' if the result is less than zero, '0' if the result is
+        zero or negative zero, or '1' if the result is greater than zero.
+
+        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('3'))
+        Decimal('-1')
+        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('2.1'))
+        Decimal('0')
+        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('2.10'))
+        Decimal('0')
+        >>> ExtendedContext.compare(Decimal('3'), Decimal('2.1'))
+        Decimal('1')
+        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('-3'))
+        Decimal('1')
+        >>> ExtendedContext.compare(Decimal('-3'), Decimal('2.1'))
+        Decimal('-1')
+        >>> ExtendedContext.compare(1, 2)
+        Decimal('-1')
+        >>> ExtendedContext.compare(Decimal(1), 2)
+        Decimal('-1')
+        >>> ExtendedContext.compare(1, Decimal(2))
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.compare(b, context=self)
+
+    def compare_signal(self, a, b):
+        """Compares the values of the two operands numerically.
+
+        It's pretty much like compare(), but all NaNs signal, with signaling
+        NaNs taking precedence over quiet NaNs.
+
+        >>> c = ExtendedContext
+        >>> c.compare_signal(Decimal('2.1'), Decimal('3'))
+        Decimal('-1')
+        >>> c.compare_signal(Decimal('2.1'), Decimal('2.1'))
+        Decimal('0')
+        >>> c.flags[InvalidOperation] = 0
+        >>> print(c.flags[InvalidOperation])
+        0
+        >>> c.compare_signal(Decimal('NaN'), Decimal('2.1'))
+        Decimal('NaN')
+        >>> print(c.flags[InvalidOperation])
+        1
+        >>> c.flags[InvalidOperation] = 0
+        >>> print(c.flags[InvalidOperation])
+        0
+        >>> c.compare_signal(Decimal('sNaN'), Decimal('2.1'))
+        Decimal('NaN')
+        >>> print(c.flags[InvalidOperation])
+        1
+        >>> c.compare_signal(-1, 2)
+        Decimal('-1')
+        >>> c.compare_signal(Decimal(-1), 2)
+        Decimal('-1')
+        >>> c.compare_signal(-1, Decimal(2))
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.compare_signal(b, context=self)
+
+    def compare_total(self, a, b):
+        """Compares two operands using their abstract representation.
+
+        This is not like the standard compare, which use their numerical
+        value. Note that a total ordering is defined for all possible abstract
+        representations.
+
+        >>> ExtendedContext.compare_total(Decimal('12.73'), Decimal('127.9'))
+        Decimal('-1')
+        >>> ExtendedContext.compare_total(Decimal('-127'),  Decimal('12'))
+        Decimal('-1')
+        >>> ExtendedContext.compare_total(Decimal('12.30'), Decimal('12.3'))
+        Decimal('-1')
+        >>> ExtendedContext.compare_total(Decimal('12.30'), Decimal('12.30'))
+        Decimal('0')
+        >>> ExtendedContext.compare_total(Decimal('12.3'),  Decimal('12.300'))
+        Decimal('1')
+        >>> ExtendedContext.compare_total(Decimal('12.3'),  Decimal('NaN'))
+        Decimal('-1')
+        >>> ExtendedContext.compare_total(1, 2)
+        Decimal('-1')
+        >>> ExtendedContext.compare_total(Decimal(1), 2)
+        Decimal('-1')
+        >>> ExtendedContext.compare_total(1, Decimal(2))
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.compare_total(b)
+
+    def compare_total_mag(self, a, b):
+        """Compares two operands using their abstract representation ignoring sign.
+
+        Like compare_total, but with operand's sign ignored and assumed to be 0.
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.compare_total_mag(b)
+
+    def copy_abs(self, a):
+        """Returns a copy of the operand with the sign set to 0.
+
+        >>> ExtendedContext.copy_abs(Decimal('2.1'))
+        Decimal('2.1')
+        >>> ExtendedContext.copy_abs(Decimal('-100'))
+        Decimal('100')
+        >>> ExtendedContext.copy_abs(-1)
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.copy_abs()
+
+    def copy_decimal(self, a):
+        """Returns a copy of the decimal object.
+
+        >>> ExtendedContext.copy_decimal(Decimal('2.1'))
+        Decimal('2.1')
+        >>> ExtendedContext.copy_decimal(Decimal('-1.00'))
+        Decimal('-1.00')
+        >>> ExtendedContext.copy_decimal(1)
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return Decimal(a)
+
+    def copy_negate(self, a):
+        """Returns a copy of the operand with the sign inverted.
+
+        >>> ExtendedContext.copy_negate(Decimal('101.5'))
+        Decimal('-101.5')
+        >>> ExtendedContext.copy_negate(Decimal('-101.5'))
+        Decimal('101.5')
+        >>> ExtendedContext.copy_negate(1)
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.copy_negate()
+
+    def copy_sign(self, a, b):
+        """Copies the second operand's sign to the first one.
+
+        In detail, it returns a copy of the first operand with the sign
+        equal to the sign of the second operand.
+
+        >>> ExtendedContext.copy_sign(Decimal( '1.50'), Decimal('7.33'))
+        Decimal('1.50')
+        >>> ExtendedContext.copy_sign(Decimal('-1.50'), Decimal('7.33'))
+        Decimal('1.50')
+        >>> ExtendedContext.copy_sign(Decimal( '1.50'), Decimal('-7.33'))
+        Decimal('-1.50')
+        >>> ExtendedContext.copy_sign(Decimal('-1.50'), Decimal('-7.33'))
+        Decimal('-1.50')
+        >>> ExtendedContext.copy_sign(1, -2)
+        Decimal('-1')
+        >>> ExtendedContext.copy_sign(Decimal(1), -2)
+        Decimal('-1')
+        >>> ExtendedContext.copy_sign(1, Decimal(-2))
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.copy_sign(b)
+
+    def divide(self, a, b):
+        """Decimal division in a specified context.
+
+        >>> ExtendedContext.divide(Decimal('1'), Decimal('3'))
+        Decimal('0.333333333')
+        >>> ExtendedContext.divide(Decimal('2'), Decimal('3'))
+        Decimal('0.666666667')
+        >>> ExtendedContext.divide(Decimal('5'), Decimal('2'))
+        Decimal('2.5')
+        >>> ExtendedContext.divide(Decimal('1'), Decimal('10'))
+        Decimal('0.1')
+        >>> ExtendedContext.divide(Decimal('12'), Decimal('12'))
+        Decimal('1')
+        >>> ExtendedContext.divide(Decimal('8.00'), Decimal('2'))
+        Decimal('4.00')
+        >>> ExtendedContext.divide(Decimal('2.400'), Decimal('2.0'))
+        Decimal('1.20')
+        >>> ExtendedContext.divide(Decimal('1000'), Decimal('100'))
+        Decimal('10')
+        >>> ExtendedContext.divide(Decimal('1000'), Decimal('1'))
+        Decimal('1000')
+        >>> ExtendedContext.divide(Decimal('2.40E+6'), Decimal('2'))
+        Decimal('1.20E+6')
+        >>> ExtendedContext.divide(5, 5)
+        Decimal('1')
+        >>> ExtendedContext.divide(Decimal(5), 5)
+        Decimal('1')
+        >>> ExtendedContext.divide(5, Decimal(5))
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__truediv__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def divide_int(self, a, b):
+        """Divides two numbers and returns the integer part of the result.
+
+        >>> ExtendedContext.divide_int(Decimal('2'), Decimal('3'))
+        Decimal('0')
+        >>> ExtendedContext.divide_int(Decimal('10'), Decimal('3'))
+        Decimal('3')
+        >>> ExtendedContext.divide_int(Decimal('1'), Decimal('0.3'))
+        Decimal('3')
+        >>> ExtendedContext.divide_int(10, 3)
+        Decimal('3')
+        >>> ExtendedContext.divide_int(Decimal(10), 3)
+        Decimal('3')
+        >>> ExtendedContext.divide_int(10, Decimal(3))
+        Decimal('3')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__floordiv__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def divmod(self, a, b):
+        """Return (a // b, a % b).
+
+        >>> ExtendedContext.divmod(Decimal(8), Decimal(3))
+        (Decimal('2'), Decimal('2'))
+        >>> ExtendedContext.divmod(Decimal(8), Decimal(4))
+        (Decimal('2'), Decimal('0'))
+        >>> ExtendedContext.divmod(8, 4)
+        (Decimal('2'), Decimal('0'))
+        >>> ExtendedContext.divmod(Decimal(8), 4)
+        (Decimal('2'), Decimal('0'))
+        >>> ExtendedContext.divmod(8, Decimal(4))
+        (Decimal('2'), Decimal('0'))
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__divmod__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def exp(self, a):
+        """Returns e ** a.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.exp(Decimal('-Infinity'))
+        Decimal('0')
+        >>> c.exp(Decimal('-1'))
+        Decimal('0.367879441')
+        >>> c.exp(Decimal('0'))
+        Decimal('1')
+        >>> c.exp(Decimal('1'))
+        Decimal('2.71828183')
+        >>> c.exp(Decimal('0.693147181'))
+        Decimal('2.00000000')
+        >>> c.exp(Decimal('+Infinity'))
+        Decimal('Infinity')
+        >>> c.exp(10)
+        Decimal('22026.4658')
+        """
+        a =_convert_other(a, raiseit=True)
+        return a.exp(context=self)
+
+    def fma(self, a, b, c):
+        """Returns a multiplied by b, plus c.
+
+        The first two operands are multiplied together, using multiply,
+        the third operand is then added to the result of that
+        multiplication, using add, all with only one final rounding.
+
+        >>> ExtendedContext.fma(Decimal('3'), Decimal('5'), Decimal('7'))
+        Decimal('22')
+        >>> ExtendedContext.fma(Decimal('3'), Decimal('-5'), Decimal('7'))
+        Decimal('-8')
+        >>> ExtendedContext.fma(Decimal('888565290'), Decimal('1557.96930'), Decimal('-86087.7578'))
+        Decimal('1.38435736E+12')
+        >>> ExtendedContext.fma(1, 3, 4)
+        Decimal('7')
+        >>> ExtendedContext.fma(1, Decimal(3), 4)
+        Decimal('7')
+        >>> ExtendedContext.fma(1, 3, Decimal(4))
+        Decimal('7')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.fma(b, c, context=self)
+
+    def is_canonical(self, a):
+        """Return True if the operand is canonical; otherwise return False.
+
+        Currently, the encoding of a Decimal instance is always
+        canonical, so this method returns True for any Decimal.
+
+        >>> ExtendedContext.is_canonical(Decimal('2.50'))
+        True
+        """
+        if not isinstance(a, Decimal):
+            raise TypeError("is_canonical requires a Decimal as an argument.")
+        return a.is_canonical()
+
+    def is_finite(self, a):
+        """Return True if the operand is finite; otherwise return False.
+
+        A Decimal instance is considered finite if it is neither
+        infinite nor a NaN.
+
+        >>> ExtendedContext.is_finite(Decimal('2.50'))
+        True
+        >>> ExtendedContext.is_finite(Decimal('-0.3'))
+        True
+        >>> ExtendedContext.is_finite(Decimal('0'))
+        True
+        >>> ExtendedContext.is_finite(Decimal('Inf'))
+        False
+        >>> ExtendedContext.is_finite(Decimal('NaN'))
+        False
+        >>> ExtendedContext.is_finite(1)
+        True
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_finite()
+
+    def is_infinite(self, a):
+        """Return True if the operand is infinite; otherwise return False.
+
+        >>> ExtendedContext.is_infinite(Decimal('2.50'))
+        False
+        >>> ExtendedContext.is_infinite(Decimal('-Inf'))
+        True
+        >>> ExtendedContext.is_infinite(Decimal('NaN'))
+        False
+        >>> ExtendedContext.is_infinite(1)
+        False
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_infinite()
+
+    def is_nan(self, a):
+        """Return True if the operand is a qNaN or sNaN;
+        otherwise return False.
+
+        >>> ExtendedContext.is_nan(Decimal('2.50'))
+        False
+        >>> ExtendedContext.is_nan(Decimal('NaN'))
+        True
+        >>> ExtendedContext.is_nan(Decimal('-sNaN'))
+        True
+        >>> ExtendedContext.is_nan(1)
+        False
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_nan()
+
+    def is_normal(self, a):
+        """Return True if the operand is a normal number;
+        otherwise return False.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.is_normal(Decimal('2.50'))
+        True
+        >>> c.is_normal(Decimal('0.1E-999'))
+        False
+        >>> c.is_normal(Decimal('0.00'))
+        False
+        >>> c.is_normal(Decimal('-Inf'))
+        False
+        >>> c.is_normal(Decimal('NaN'))
+        False
+        >>> c.is_normal(1)
+        True
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_normal(context=self)
+
+    def is_qnan(self, a):
+        """Return True if the operand is a quiet NaN; otherwise return False.
+
+        >>> ExtendedContext.is_qnan(Decimal('2.50'))
+        False
+        >>> ExtendedContext.is_qnan(Decimal('NaN'))
+        True
+        >>> ExtendedContext.is_qnan(Decimal('sNaN'))
+        False
+        >>> ExtendedContext.is_qnan(1)
+        False
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_qnan()
+
+    def is_signed(self, a):
+        """Return True if the operand is negative; otherwise return False.
+
+        >>> ExtendedContext.is_signed(Decimal('2.50'))
+        False
+        >>> ExtendedContext.is_signed(Decimal('-12'))
+        True
+        >>> ExtendedContext.is_signed(Decimal('-0'))
+        True
+        >>> ExtendedContext.is_signed(8)
+        False
+        >>> ExtendedContext.is_signed(-8)
+        True
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_signed()
+
+    def is_snan(self, a):
+        """Return True if the operand is a signaling NaN;
+        otherwise return False.
+
+        >>> ExtendedContext.is_snan(Decimal('2.50'))
+        False
+        >>> ExtendedContext.is_snan(Decimal('NaN'))
+        False
+        >>> ExtendedContext.is_snan(Decimal('sNaN'))
+        True
+        >>> ExtendedContext.is_snan(1)
+        False
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_snan()
+
+    def is_subnormal(self, a):
+        """Return True if the operand is subnormal; otherwise return False.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.is_subnormal(Decimal('2.50'))
+        False
+        >>> c.is_subnormal(Decimal('0.1E-999'))
+        True
+        >>> c.is_subnormal(Decimal('0.00'))
+        False
+        >>> c.is_subnormal(Decimal('-Inf'))
+        False
+        >>> c.is_subnormal(Decimal('NaN'))
+        False
+        >>> c.is_subnormal(1)
+        False
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_subnormal(context=self)
+
+    def is_zero(self, a):
+        """Return True if the operand is a zero; otherwise return False.
+
+        >>> ExtendedContext.is_zero(Decimal('0'))
+        True
+        >>> ExtendedContext.is_zero(Decimal('2.50'))
+        False
+        >>> ExtendedContext.is_zero(Decimal('-0E+2'))
+        True
+        >>> ExtendedContext.is_zero(1)
+        False
+        >>> ExtendedContext.is_zero(0)
+        True
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.is_zero()
+
+    def ln(self, a):
+        """Returns the natural (base e) logarithm of the operand.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.ln(Decimal('0'))
+        Decimal('-Infinity')
+        >>> c.ln(Decimal('1.000'))
+        Decimal('0')
+        >>> c.ln(Decimal('2.71828183'))
+        Decimal('1.00000000')
+        >>> c.ln(Decimal('10'))
+        Decimal('2.30258509')
+        >>> c.ln(Decimal('+Infinity'))
+        Decimal('Infinity')
+        >>> c.ln(1)
+        Decimal('0')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.ln(context=self)
+
+    def log10(self, a):
+        """Returns the base 10 logarithm of the operand.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.log10(Decimal('0'))
+        Decimal('-Infinity')
+        >>> c.log10(Decimal('0.001'))
+        Decimal('-3')
+        >>> c.log10(Decimal('1.000'))
+        Decimal('0')
+        >>> c.log10(Decimal('2'))
+        Decimal('0.301029996')
+        >>> c.log10(Decimal('10'))
+        Decimal('1')
+        >>> c.log10(Decimal('70'))
+        Decimal('1.84509804')
+        >>> c.log10(Decimal('+Infinity'))
+        Decimal('Infinity')
+        >>> c.log10(0)
+        Decimal('-Infinity')
+        >>> c.log10(1)
+        Decimal('0')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.log10(context=self)
+
+    def logb(self, a):
+        """ Returns the exponent of the magnitude of the operand's MSD.
+
+        The result is the integer which is the exponent of the magnitude
+        of the most significant digit of the operand (as though the
+        operand were truncated to a single digit while maintaining the
+        value of that digit and without limiting the resulting exponent).
+
+        >>> ExtendedContext.logb(Decimal('250'))
+        Decimal('2')
+        >>> ExtendedContext.logb(Decimal('2.50'))
+        Decimal('0')
+        >>> ExtendedContext.logb(Decimal('0.03'))
+        Decimal('-2')
+        >>> ExtendedContext.logb(Decimal('0'))
+        Decimal('-Infinity')
+        >>> ExtendedContext.logb(1)
+        Decimal('0')
+        >>> ExtendedContext.logb(10)
+        Decimal('1')
+        >>> ExtendedContext.logb(100)
+        Decimal('2')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.logb(context=self)
+
+    def logical_and(self, a, b):
+        """Applies the logical operation 'and' between each operand's digits.
+
+        The operands must be both logical numbers.
+
+        >>> ExtendedContext.logical_and(Decimal('0'), Decimal('0'))
+        Decimal('0')
+        >>> ExtendedContext.logical_and(Decimal('0'), Decimal('1'))
+        Decimal('0')
+        >>> ExtendedContext.logical_and(Decimal('1'), Decimal('0'))
+        Decimal('0')
+        >>> ExtendedContext.logical_and(Decimal('1'), Decimal('1'))
+        Decimal('1')
+        >>> ExtendedContext.logical_and(Decimal('1100'), Decimal('1010'))
+        Decimal('1000')
+        >>> ExtendedContext.logical_and(Decimal('1111'), Decimal('10'))
+        Decimal('10')
+        >>> ExtendedContext.logical_and(110, 1101)
+        Decimal('100')
+        >>> ExtendedContext.logical_and(Decimal(110), 1101)
+        Decimal('100')
+        >>> ExtendedContext.logical_and(110, Decimal(1101))
+        Decimal('100')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.logical_and(b, context=self)
+
+    def logical_invert(self, a):
+        """Invert all the digits in the operand.
+
+        The operand must be a logical number.
+
+        >>> ExtendedContext.logical_invert(Decimal('0'))
+        Decimal('111111111')
+        >>> ExtendedContext.logical_invert(Decimal('1'))
+        Decimal('111111110')
+        >>> ExtendedContext.logical_invert(Decimal('111111111'))
+        Decimal('0')
+        >>> ExtendedContext.logical_invert(Decimal('101010101'))
+        Decimal('10101010')
+        >>> ExtendedContext.logical_invert(1101)
+        Decimal('111110010')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.logical_invert(context=self)
+
+    def logical_or(self, a, b):
+        """Applies the logical operation 'or' between each operand's digits.
+
+        The operands must be both logical numbers.
+
+        >>> ExtendedContext.logical_or(Decimal('0'), Decimal('0'))
+        Decimal('0')
+        >>> ExtendedContext.logical_or(Decimal('0'), Decimal('1'))
+        Decimal('1')
+        >>> ExtendedContext.logical_or(Decimal('1'), Decimal('0'))
+        Decimal('1')
+        >>> ExtendedContext.logical_or(Decimal('1'), Decimal('1'))
+        Decimal('1')
+        >>> ExtendedContext.logical_or(Decimal('1100'), Decimal('1010'))
+        Decimal('1110')
+        >>> ExtendedContext.logical_or(Decimal('1110'), Decimal('10'))
+        Decimal('1110')
+        >>> ExtendedContext.logical_or(110, 1101)
+        Decimal('1111')
+        >>> ExtendedContext.logical_or(Decimal(110), 1101)
+        Decimal('1111')
+        >>> ExtendedContext.logical_or(110, Decimal(1101))
+        Decimal('1111')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.logical_or(b, context=self)
+
+    def logical_xor(self, a, b):
+        """Applies the logical operation 'xor' between each operand's digits.
+
+        The operands must be both logical numbers.
+
+        >>> ExtendedContext.logical_xor(Decimal('0'), Decimal('0'))
+        Decimal('0')
+        >>> ExtendedContext.logical_xor(Decimal('0'), Decimal('1'))
+        Decimal('1')
+        >>> ExtendedContext.logical_xor(Decimal('1'), Decimal('0'))
+        Decimal('1')
+        >>> ExtendedContext.logical_xor(Decimal('1'), Decimal('1'))
+        Decimal('0')
+        >>> ExtendedContext.logical_xor(Decimal('1100'), Decimal('1010'))
+        Decimal('110')
+        >>> ExtendedContext.logical_xor(Decimal('1111'), Decimal('10'))
+        Decimal('1101')
+        >>> ExtendedContext.logical_xor(110, 1101)
+        Decimal('1011')
+        >>> ExtendedContext.logical_xor(Decimal(110), 1101)
+        Decimal('1011')
+        >>> ExtendedContext.logical_xor(110, Decimal(1101))
+        Decimal('1011')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.logical_xor(b, context=self)
+
+    def max(self, a, b):
+        """max compares two values numerically and returns the maximum.
+
+        If either operand is a NaN then the general rules apply.
+        Otherwise, the operands are compared as though by the compare
+        operation.  If they are numerically equal then the left-hand operand
+        is chosen as the result.  Otherwise the maximum (closer to positive
+        infinity) of the two operands is chosen as the result.
+
+        >>> ExtendedContext.max(Decimal('3'), Decimal('2'))
+        Decimal('3')
+        >>> ExtendedContext.max(Decimal('-10'), Decimal('3'))
+        Decimal('3')
+        >>> ExtendedContext.max(Decimal('1.0'), Decimal('1'))
+        Decimal('1')
+        >>> ExtendedContext.max(Decimal('7'), Decimal('NaN'))
+        Decimal('7')
+        >>> ExtendedContext.max(1, 2)
+        Decimal('2')
+        >>> ExtendedContext.max(Decimal(1), 2)
+        Decimal('2')
+        >>> ExtendedContext.max(1, Decimal(2))
+        Decimal('2')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.max(b, context=self)
+
+    def max_mag(self, a, b):
+        """Compares the values numerically with their sign ignored.
+
+        >>> ExtendedContext.max_mag(Decimal('7'), Decimal('NaN'))
+        Decimal('7')
+        >>> ExtendedContext.max_mag(Decimal('7'), Decimal('-10'))
+        Decimal('-10')
+        >>> ExtendedContext.max_mag(1, -2)
+        Decimal('-2')
+        >>> ExtendedContext.max_mag(Decimal(1), -2)
+        Decimal('-2')
+        >>> ExtendedContext.max_mag(1, Decimal(-2))
+        Decimal('-2')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.max_mag(b, context=self)
+
+    def min(self, a, b):
+        """min compares two values numerically and returns the minimum.
+
+        If either operand is a NaN then the general rules apply.
+        Otherwise, the operands are compared as though by the compare
+        operation.  If they are numerically equal then the left-hand operand
+        is chosen as the result.  Otherwise the minimum (closer to negative
+        infinity) of the two operands is chosen as the result.
+
+        >>> ExtendedContext.min(Decimal('3'), Decimal('2'))
+        Decimal('2')
+        >>> ExtendedContext.min(Decimal('-10'), Decimal('3'))
+        Decimal('-10')
+        >>> ExtendedContext.min(Decimal('1.0'), Decimal('1'))
+        Decimal('1.0')
+        >>> ExtendedContext.min(Decimal('7'), Decimal('NaN'))
+        Decimal('7')
+        >>> ExtendedContext.min(1, 2)
+        Decimal('1')
+        >>> ExtendedContext.min(Decimal(1), 2)
+        Decimal('1')
+        >>> ExtendedContext.min(1, Decimal(29))
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.min(b, context=self)
+
+    def min_mag(self, a, b):
+        """Compares the values numerically with their sign ignored.
+
+        >>> ExtendedContext.min_mag(Decimal('3'), Decimal('-2'))
+        Decimal('-2')
+        >>> ExtendedContext.min_mag(Decimal('-3'), Decimal('NaN'))
+        Decimal('-3')
+        >>> ExtendedContext.min_mag(1, -2)
+        Decimal('1')
+        >>> ExtendedContext.min_mag(Decimal(1), -2)
+        Decimal('1')
+        >>> ExtendedContext.min_mag(1, Decimal(-2))
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.min_mag(b, context=self)
+
+    def minus(self, a):
+        """Minus corresponds to unary prefix minus in Python.
+
+        The operation is evaluated using the same rules as subtract; the
+        operation minus(a) is calculated as subtract('0', a) where the '0'
+        has the same exponent as the operand.
+
+        >>> ExtendedContext.minus(Decimal('1.3'))
+        Decimal('-1.3')
+        >>> ExtendedContext.minus(Decimal('-1.3'))
+        Decimal('1.3')
+        >>> ExtendedContext.minus(1)
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.__neg__(context=self)
+
+    def multiply(self, a, b):
+        """multiply multiplies two operands.
+
+        If either operand is a special value then the general rules apply.
+        Otherwise, the operands are multiplied together
+        ('long multiplication'), resulting in a number which may be as long as
+        the sum of the lengths of the two operands.
+
+        >>> ExtendedContext.multiply(Decimal('1.20'), Decimal('3'))
+        Decimal('3.60')
+        >>> ExtendedContext.multiply(Decimal('7'), Decimal('3'))
+        Decimal('21')
+        >>> ExtendedContext.multiply(Decimal('0.9'), Decimal('0.8'))
+        Decimal('0.72')
+        >>> ExtendedContext.multiply(Decimal('0.9'), Decimal('-0'))
+        Decimal('-0.0')
+        >>> ExtendedContext.multiply(Decimal('654321'), Decimal('654321'))
+        Decimal('4.28135971E+11')
+        >>> ExtendedContext.multiply(7, 7)
+        Decimal('49')
+        >>> ExtendedContext.multiply(Decimal(7), 7)
+        Decimal('49')
+        >>> ExtendedContext.multiply(7, Decimal(7))
+        Decimal('49')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__mul__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def next_minus(self, a):
+        """Returns the largest representable number smaller than a.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> ExtendedContext.next_minus(Decimal('1'))
+        Decimal('0.999999999')
+        >>> c.next_minus(Decimal('1E-1007'))
+        Decimal('0E-1007')
+        >>> ExtendedContext.next_minus(Decimal('-1.00000003'))
+        Decimal('-1.00000004')
+        >>> c.next_minus(Decimal('Infinity'))
+        Decimal('9.99999999E+999')
+        >>> c.next_minus(1)
+        Decimal('0.999999999')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.next_minus(context=self)
+
+    def next_plus(self, a):
+        """Returns the smallest representable number larger than a.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> ExtendedContext.next_plus(Decimal('1'))
+        Decimal('1.00000001')
+        >>> c.next_plus(Decimal('-1E-1007'))
+        Decimal('-0E-1007')
+        >>> ExtendedContext.next_plus(Decimal('-1.00000003'))
+        Decimal('-1.00000002')
+        >>> c.next_plus(Decimal('-Infinity'))
+        Decimal('-9.99999999E+999')
+        >>> c.next_plus(1)
+        Decimal('1.00000001')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.next_plus(context=self)
+
+    def next_toward(self, a, b):
+        """Returns the number closest to a, in direction towards b.
+
+        The result is the closest representable number from the first
+        operand (but not the first operand) that is in the direction
+        towards the second operand, unless the operands have the same
+        value.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.next_toward(Decimal('1'), Decimal('2'))
+        Decimal('1.00000001')
+        >>> c.next_toward(Decimal('-1E-1007'), Decimal('1'))
+        Decimal('-0E-1007')
+        >>> c.next_toward(Decimal('-1.00000003'), Decimal('0'))
+        Decimal('-1.00000002')
+        >>> c.next_toward(Decimal('1'), Decimal('0'))
+        Decimal('0.999999999')
+        >>> c.next_toward(Decimal('1E-1007'), Decimal('-100'))
+        Decimal('0E-1007')
+        >>> c.next_toward(Decimal('-1.00000003'), Decimal('-10'))
+        Decimal('-1.00000004')
+        >>> c.next_toward(Decimal('0.00'), Decimal('-0.0000'))
+        Decimal('-0.00')
+        >>> c.next_toward(0, 1)
+        Decimal('1E-1007')
+        >>> c.next_toward(Decimal(0), 1)
+        Decimal('1E-1007')
+        >>> c.next_toward(0, Decimal(1))
+        Decimal('1E-1007')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.next_toward(b, context=self)
+
+    def normalize(self, a):
+        """normalize reduces an operand to its simplest form.
+
+        Essentially a plus operation with all trailing zeros removed from the
+        result.
+
+        >>> ExtendedContext.normalize(Decimal('2.1'))
+        Decimal('2.1')
+        >>> ExtendedContext.normalize(Decimal('-2.0'))
+        Decimal('-2')
+        >>> ExtendedContext.normalize(Decimal('1.200'))
+        Decimal('1.2')
+        >>> ExtendedContext.normalize(Decimal('-120'))
+        Decimal('-1.2E+2')
+        >>> ExtendedContext.normalize(Decimal('120.00'))
+        Decimal('1.2E+2')
+        >>> ExtendedContext.normalize(Decimal('0.00'))
+        Decimal('0')
+        >>> ExtendedContext.normalize(6)
+        Decimal('6')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.normalize(context=self)
+
+    def number_class(self, a):
+        """Returns an indication of the class of the operand.
+
+        The class is one of the following strings:
+          -sNaN
+          -NaN
+          -Infinity
+          -Normal
+          -Subnormal
+          -Zero
+          +Zero
+          +Subnormal
+          +Normal
+          +Infinity
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.number_class(Decimal('Infinity'))
+        '+Infinity'
+        >>> c.number_class(Decimal('1E-10'))
+        '+Normal'
+        >>> c.number_class(Decimal('2.50'))
+        '+Normal'
+        >>> c.number_class(Decimal('0.1E-999'))
+        '+Subnormal'
+        >>> c.number_class(Decimal('0'))
+        '+Zero'
+        >>> c.number_class(Decimal('-0'))
+        '-Zero'
+        >>> c.number_class(Decimal('-0.1E-999'))
+        '-Subnormal'
+        >>> c.number_class(Decimal('-1E-10'))
+        '-Normal'
+        >>> c.number_class(Decimal('-2.50'))
+        '-Normal'
+        >>> c.number_class(Decimal('-Infinity'))
+        '-Infinity'
+        >>> c.number_class(Decimal('NaN'))
+        'NaN'
+        >>> c.number_class(Decimal('-NaN'))
+        'NaN'
+        >>> c.number_class(Decimal('sNaN'))
+        'sNaN'
+        >>> c.number_class(123)
+        '+Normal'
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.number_class(context=self)
+
+    def plus(self, a):
+        """Plus corresponds to unary prefix plus in Python.
+
+        The operation is evaluated using the same rules as add; the
+        operation plus(a) is calculated as add('0', a) where the '0'
+        has the same exponent as the operand.
+
+        >>> ExtendedContext.plus(Decimal('1.3'))
+        Decimal('1.3')
+        >>> ExtendedContext.plus(Decimal('-1.3'))
+        Decimal('-1.3')
+        >>> ExtendedContext.plus(-1)
+        Decimal('-1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.__pos__(context=self)
+
+    def power(self, a, b, modulo=None):
+        """Raises a to the power of b, to modulo if given.
+
+        With two arguments, compute a**b.  If a is negative then b
+        must be integral.  The result will be inexact unless b is
+        integral and the result is finite and can be expressed exactly
+        in 'precision' digits.
+
+        With three arguments, compute (a**b) % modulo.  For the
+        three argument form, the following restrictions on the
+        arguments hold:
+
+         - all three arguments must be integral
+         - b must be nonnegative
+         - at least one of a or b must be nonzero
+         - modulo must be nonzero and have at most 'precision' digits
+
+        The result of pow(a, b, modulo) is identical to the result
+        that would be obtained by computing (a**b) % modulo with
+        unbounded precision, but is computed more efficiently.  It is
+        always exact.
+
+        >>> c = ExtendedContext.copy()
+        >>> c.Emin = -999
+        >>> c.Emax = 999
+        >>> c.power(Decimal('2'), Decimal('3'))
+        Decimal('8')
+        >>> c.power(Decimal('-2'), Decimal('3'))
+        Decimal('-8')
+        >>> c.power(Decimal('2'), Decimal('-3'))
+        Decimal('0.125')
+        >>> c.power(Decimal('1.7'), Decimal('8'))
+        Decimal('69.7575744')
+        >>> c.power(Decimal('10'), Decimal('0.301029996'))
+        Decimal('2.00000000')
+        >>> c.power(Decimal('Infinity'), Decimal('-1'))
+        Decimal('0')
+        >>> c.power(Decimal('Infinity'), Decimal('0'))
+        Decimal('1')
+        >>> c.power(Decimal('Infinity'), Decimal('1'))
+        Decimal('Infinity')
+        >>> c.power(Decimal('-Infinity'), Decimal('-1'))
+        Decimal('-0')
+        >>> c.power(Decimal('-Infinity'), Decimal('0'))
+        Decimal('1')
+        >>> c.power(Decimal('-Infinity'), Decimal('1'))
+        Decimal('-Infinity')
+        >>> c.power(Decimal('-Infinity'), Decimal('2'))
+        Decimal('Infinity')
+        >>> c.power(Decimal('0'), Decimal('0'))
+        Decimal('NaN')
+
+        >>> c.power(Decimal('3'), Decimal('7'), Decimal('16'))
+        Decimal('11')
+        >>> c.power(Decimal('-3'), Decimal('7'), Decimal('16'))
+        Decimal('-11')
+        >>> c.power(Decimal('-3'), Decimal('8'), Decimal('16'))
+        Decimal('1')
+        >>> c.power(Decimal('3'), Decimal('7'), Decimal('-16'))
+        Decimal('11')
+        >>> c.power(Decimal('23E12345'), Decimal('67E189'), Decimal('123456789'))
+        Decimal('11729830')
+        >>> c.power(Decimal('-0'), Decimal('17'), Decimal('1729'))
+        Decimal('-0')
+        >>> c.power(Decimal('-23'), Decimal('0'), Decimal('65537'))
+        Decimal('1')
+        >>> ExtendedContext.power(7, 7)
+        Decimal('823543')
+        >>> ExtendedContext.power(Decimal(7), 7)
+        Decimal('823543')
+        >>> ExtendedContext.power(7, Decimal(7), 2)
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__pow__(b, modulo, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def quantize(self, a, b):
+        """Returns a value equal to 'a' (rounded), having the exponent of 'b'.
+
+        The coefficient of the result is derived from that of the left-hand
+        operand.  It may be rounded using the current rounding setting (if the
+        exponent is being increased), multiplied by a positive power of ten (if
+        the exponent is being decreased), or is unchanged (if the exponent is
+        already equal to that of the right-hand operand).
+
+        Unlike other operations, if the length of the coefficient after the
+        quantize operation would be greater than precision then an Invalid
+        operation condition is raised.  This guarantees that, unless there is
+        an error condition, the exponent of the result of a quantize is always
+        equal to that of the right-hand operand.
+
+        Also unlike other operations, quantize will never raise Underflow, even
+        if the result is subnormal and inexact.
+
+        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.001'))
+        Decimal('2.170')
+        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.01'))
+        Decimal('2.17')
+        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.1'))
+        Decimal('2.2')
+        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('1e+0'))
+        Decimal('2')
+        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('1e+1'))
+        Decimal('0E+1')
+        >>> ExtendedContext.quantize(Decimal('-Inf'), Decimal('Infinity'))
+        Decimal('-Infinity')
+        >>> ExtendedContext.quantize(Decimal('2'), Decimal('Infinity'))
+        Decimal('NaN')
+        >>> ExtendedContext.quantize(Decimal('-0.1'), Decimal('1'))
+        Decimal('-0')
+        >>> ExtendedContext.quantize(Decimal('-0'), Decimal('1e+5'))
+        Decimal('-0E+5')
+        >>> ExtendedContext.quantize(Decimal('+35236450.6'), Decimal('1e-2'))
+        Decimal('NaN')
+        >>> ExtendedContext.quantize(Decimal('-35236450.6'), Decimal('1e-2'))
+        Decimal('NaN')
+        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e-1'))
+        Decimal('217.0')
+        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e-0'))
+        Decimal('217')
+        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e+1'))
+        Decimal('2.2E+2')
+        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e+2'))
+        Decimal('2E+2')
+        >>> ExtendedContext.quantize(1, 2)
+        Decimal('1')
+        >>> ExtendedContext.quantize(Decimal(1), 2)
+        Decimal('1')
+        >>> ExtendedContext.quantize(1, Decimal(2))
+        Decimal('1')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.quantize(b, context=self)
+
+    def radix(self):
+        """Just returns 10, as this is Decimal, :)
+
+        >>> ExtendedContext.radix()
+        Decimal('10')
+        """
+        return Decimal(10)
+
+    def remainder(self, a, b):
+        """Returns the remainder from integer division.
+
+        The result is the residue of the dividend after the operation of
+        calculating integer division as described for divide-integer, rounded
+        to precision digits if necessary.  The sign of the result, if
+        non-zero, is the same as that of the original dividend.
+
+        This operation will fail under the same conditions as integer division
+        (that is, if integer division on the same two operands would fail, the
+        remainder cannot be calculated).
+
+        >>> ExtendedContext.remainder(Decimal('2.1'), Decimal('3'))
+        Decimal('2.1')
+        >>> ExtendedContext.remainder(Decimal('10'), Decimal('3'))
+        Decimal('1')
+        >>> ExtendedContext.remainder(Decimal('-10'), Decimal('3'))
+        Decimal('-1')
+        >>> ExtendedContext.remainder(Decimal('10.2'), Decimal('1'))
+        Decimal('0.2')
+        >>> ExtendedContext.remainder(Decimal('10'), Decimal('0.3'))
+        Decimal('0.1')
+        >>> ExtendedContext.remainder(Decimal('3.6'), Decimal('1.3'))
+        Decimal('1.0')
+        >>> ExtendedContext.remainder(22, 6)
+        Decimal('4')
+        >>> ExtendedContext.remainder(Decimal(22), 6)
+        Decimal('4')
+        >>> ExtendedContext.remainder(22, Decimal(6))
+        Decimal('4')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__mod__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def remainder_near(self, a, b):
+        """Returns to be "a - b * n", where n is the integer nearest the exact
+        value of "x / b" (if two integers are equally near then the even one
+        is chosen).  If the result is equal to 0 then its sign will be the
+        sign of a.
+
+        This operation will fail under the same conditions as integer division
+        (that is, if integer division on the same two operands would fail, the
+        remainder cannot be calculated).
+
+        >>> ExtendedContext.remainder_near(Decimal('2.1'), Decimal('3'))
+        Decimal('-0.9')
+        >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('6'))
+        Decimal('-2')
+        >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('3'))
+        Decimal('1')
+        >>> ExtendedContext.remainder_near(Decimal('-10'), Decimal('3'))
+        Decimal('-1')
+        >>> ExtendedContext.remainder_near(Decimal('10.2'), Decimal('1'))
+        Decimal('0.2')
+        >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('0.3'))
+        Decimal('0.1')
+        >>> ExtendedContext.remainder_near(Decimal('3.6'), Decimal('1.3'))
+        Decimal('-0.3')
+        >>> ExtendedContext.remainder_near(3, 11)
+        Decimal('3')
+        >>> ExtendedContext.remainder_near(Decimal(3), 11)
+        Decimal('3')
+        >>> ExtendedContext.remainder_near(3, Decimal(11))
+        Decimal('3')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.remainder_near(b, context=self)
+
+    def rotate(self, a, b):
+        """Returns a rotated copy of a, b times.
+
+        The coefficient of the result is a rotated copy of the digits in
+        the coefficient of the first operand.  The number of places of
+        rotation is taken from the absolute value of the second operand,
+        with the rotation being to the left if the second operand is
+        positive or to the right otherwise.
+
+        >>> ExtendedContext.rotate(Decimal('34'), Decimal('8'))
+        Decimal('400000003')
+        >>> ExtendedContext.rotate(Decimal('12'), Decimal('9'))
+        Decimal('12')
+        >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('-2'))
+        Decimal('891234567')
+        >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('0'))
+        Decimal('123456789')
+        >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('+2'))
+        Decimal('345678912')
+        >>> ExtendedContext.rotate(1333333, 1)
+        Decimal('13333330')
+        >>> ExtendedContext.rotate(Decimal(1333333), 1)
+        Decimal('13333330')
+        >>> ExtendedContext.rotate(1333333, Decimal(1))
+        Decimal('13333330')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.rotate(b, context=self)
+
+    def same_quantum(self, a, b):
+        """Returns True if the two operands have the same exponent.
+
+        The result is never affected by either the sign or the coefficient of
+        either operand.
+
+        >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('0.001'))
+        False
+        >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('0.01'))
+        True
+        >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('1'))
+        False
+        >>> ExtendedContext.same_quantum(Decimal('Inf'), Decimal('-Inf'))
+        True
+        >>> ExtendedContext.same_quantum(10000, -1)
+        True
+        >>> ExtendedContext.same_quantum(Decimal(10000), -1)
+        True
+        >>> ExtendedContext.same_quantum(10000, Decimal(-1))
+        True
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.same_quantum(b)
+
+    def scaleb (self, a, b):
+        """Returns the first operand after adding the second value its exp.
+
+        >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('-2'))
+        Decimal('0.0750')
+        >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('0'))
+        Decimal('7.50')
+        >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('3'))
+        Decimal('7.50E+3')
+        >>> ExtendedContext.scaleb(1, 4)
+        Decimal('1E+4')
+        >>> ExtendedContext.scaleb(Decimal(1), 4)
+        Decimal('1E+4')
+        >>> ExtendedContext.scaleb(1, Decimal(4))
+        Decimal('1E+4')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.scaleb(b, context=self)
+
+    def shift(self, a, b):
+        """Returns a shifted copy of a, b times.
+
+        The coefficient of the result is a shifted copy of the digits
+        in the coefficient of the first operand.  The number of places
+        to shift is taken from the absolute value of the second operand,
+        with the shift being to the left if the second operand is
+        positive or to the right otherwise.  Digits shifted into the
+        coefficient are zeros.
+
+        >>> ExtendedContext.shift(Decimal('34'), Decimal('8'))
+        Decimal('400000000')
+        >>> ExtendedContext.shift(Decimal('12'), Decimal('9'))
+        Decimal('0')
+        >>> ExtendedContext.shift(Decimal('123456789'), Decimal('-2'))
+        Decimal('1234567')
+        >>> ExtendedContext.shift(Decimal('123456789'), Decimal('0'))
+        Decimal('123456789')
+        >>> ExtendedContext.shift(Decimal('123456789'), Decimal('+2'))
+        Decimal('345678900')
+        >>> ExtendedContext.shift(88888888, 2)
+        Decimal('888888800')
+        >>> ExtendedContext.shift(Decimal(88888888), 2)
+        Decimal('888888800')
+        >>> ExtendedContext.shift(88888888, Decimal(2))
+        Decimal('888888800')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.shift(b, context=self)
+
+    def sqrt(self, a):
+        """Square root of a non-negative number to context precision.
+
+        If the result must be inexact, it is rounded using the round-half-even
+        algorithm.
+
+        >>> ExtendedContext.sqrt(Decimal('0'))
+        Decimal('0')
+        >>> ExtendedContext.sqrt(Decimal('-0'))
+        Decimal('-0')
+        >>> ExtendedContext.sqrt(Decimal('0.39'))
+        Decimal('0.624499800')
+        >>> ExtendedContext.sqrt(Decimal('100'))
+        Decimal('10')
+        >>> ExtendedContext.sqrt(Decimal('1'))
+        Decimal('1')
+        >>> ExtendedContext.sqrt(Decimal('1.0'))
+        Decimal('1.0')
+        >>> ExtendedContext.sqrt(Decimal('1.00'))
+        Decimal('1.0')
+        >>> ExtendedContext.sqrt(Decimal('7'))
+        Decimal('2.64575131')
+        >>> ExtendedContext.sqrt(Decimal('10'))
+        Decimal('3.16227766')
+        >>> ExtendedContext.sqrt(2)
+        Decimal('1.41421356')
+        >>> ExtendedContext.prec
+        9
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.sqrt(context=self)
+
+    def subtract(self, a, b):
+        """Return the difference between the two operands.
+
+        >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('1.07'))
+        Decimal('0.23')
+        >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('1.30'))
+        Decimal('0.00')
+        >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('2.07'))
+        Decimal('-0.77')
+        >>> ExtendedContext.subtract(8, 5)
+        Decimal('3')
+        >>> ExtendedContext.subtract(Decimal(8), 5)
+        Decimal('3')
+        >>> ExtendedContext.subtract(8, Decimal(5))
+        Decimal('3')
+        """
+        a = _convert_other(a, raiseit=True)
+        r = a.__sub__(b, context=self)
+        if r is NotImplemented:
+            raise TypeError("Unable to convert %s to Decimal" % b)
+        else:
+            return r
+
+    def to_eng_string(self, a):
+        """Converts a number to a string, using scientific notation.
+
+        The operation is not affected by the context.
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.to_eng_string(context=self)
+
+    def to_sci_string(self, a):
+        """Converts a number to a string, using scientific notation.
+
+        The operation is not affected by the context.
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.__str__(context=self)
+
+    def to_integral_exact(self, a):
+        """Rounds to an integer.
+
+        When the operand has a negative exponent, the result is the same
+        as using the quantize() operation using the given operand as the
+        left-hand-operand, 1E+0 as the right-hand-operand, and the precision
+        of the operand as the precision setting; Inexact and Rounded flags
+        are allowed in this operation.  The rounding mode is taken from the
+        context.
+
+        >>> ExtendedContext.to_integral_exact(Decimal('2.1'))
+        Decimal('2')
+        >>> ExtendedContext.to_integral_exact(Decimal('100'))
+        Decimal('100')
+        >>> ExtendedContext.to_integral_exact(Decimal('100.0'))
+        Decimal('100')
+        >>> ExtendedContext.to_integral_exact(Decimal('101.5'))
+        Decimal('102')
+        >>> ExtendedContext.to_integral_exact(Decimal('-101.5'))
+        Decimal('-102')
+        >>> ExtendedContext.to_integral_exact(Decimal('10E+5'))
+        Decimal('1.0E+6')
+        >>> ExtendedContext.to_integral_exact(Decimal('7.89E+77'))
+        Decimal('7.89E+77')
+        >>> ExtendedContext.to_integral_exact(Decimal('-Inf'))
+        Decimal('-Infinity')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.to_integral_exact(context=self)
+
+    def to_integral_value(self, a):
+        """Rounds to an integer.
+
+        When the operand has a negative exponent, the result is the same
+        as using the quantize() operation using the given operand as the
+        left-hand-operand, 1E+0 as the right-hand-operand, and the precision
+        of the operand as the precision setting, except that no flags will
+        be set.  The rounding mode is taken from the context.
+
+        >>> ExtendedContext.to_integral_value(Decimal('2.1'))
+        Decimal('2')
+        >>> ExtendedContext.to_integral_value(Decimal('100'))
+        Decimal('100')
+        >>> ExtendedContext.to_integral_value(Decimal('100.0'))
+        Decimal('100')
+        >>> ExtendedContext.to_integral_value(Decimal('101.5'))
+        Decimal('102')
+        >>> ExtendedContext.to_integral_value(Decimal('-101.5'))
+        Decimal('-102')
+        >>> ExtendedContext.to_integral_value(Decimal('10E+5'))
+        Decimal('1.0E+6')
+        >>> ExtendedContext.to_integral_value(Decimal('7.89E+77'))
+        Decimal('7.89E+77')
+        >>> ExtendedContext.to_integral_value(Decimal('-Inf'))
+        Decimal('-Infinity')
+        """
+        a = _convert_other(a, raiseit=True)
+        return a.to_integral_value(context=self)
+
+    # the method name changed, but we provide also the old one, for compatibility
+    to_integral = to_integral_value
+
+class _WorkRep(object):
+    __slots__ = ('sign','int','exp')
+    # sign: 0 or 1
+    # int:  int
+    # exp:  None, int, or string
+
+    def __init__(self, value=None):
+        if value is None:
+            self.sign = None
+            self.int = 0
+            self.exp = None
+        elif isinstance(value, Decimal):
+            self.sign = value._sign
+            self.int = int(value._int)
+            self.exp = value._exp
+        else:
+            # assert isinstance(value, tuple)
+            self.sign = value[0]
+            self.int = value[1]
+            self.exp = value[2]
+
+    def __repr__(self):
+        return "(%r, %r, %r)" % (self.sign, self.int, self.exp)
+
+    __str__ = __repr__
+
+
+
+def _normalize(op1, op2, prec = 0):
+    """Normalizes op1, op2 to have the same exp and length of coefficient.
+
+    Done during addition.
+    """
+    if op1.exp < op2.exp:
+        tmp = op2
+        other = op1
+    else:
+        tmp = op1
+        other = op2
+
+    # Let exp = min(tmp.exp - 1, tmp.adjusted() - precision - 1).
+    # Then adding 10**exp to tmp has the same effect (after rounding)
+    # as adding any positive quantity smaller than 10**exp; similarly
+    # for subtraction.  So if other is smaller than 10**exp we replace
+    # it with 10**exp.  This avoids tmp.exp - other.exp getting too large.
+    tmp_len = len(str(tmp.int))
+    other_len = len(str(other.int))
+    exp = tmp.exp + min(-1, tmp_len - prec - 2)
+    if other_len + other.exp - 1 < exp:
+        other.int = 1
+        other.exp = exp
+
+    tmp.int *= 10 ** (tmp.exp - other.exp)
+    tmp.exp = other.exp
+    return op1, op2
+
+##### Integer arithmetic functions used by ln, log10, exp and __pow__ #####
+
+_nbits = int.bit_length
+
+def _decimal_lshift_exact(n, e):
+    """ Given integers n and e, return n * 10**e if it's an integer, else None.
+
+    The computation is designed to avoid computing large powers of 10
+    unnecessarily.
+
+    >>> _decimal_lshift_exact(3, 4)
+    30000
+    >>> _decimal_lshift_exact(300, -999999999)  # returns None
+
+    """
+    if n == 0:
+        return 0
+    elif e >= 0:
+        return n * 10**e
+    else:
+        # val_n = largest power of 10 dividing n.
+        str_n = str(abs(n))
+        val_n = len(str_n) - len(str_n.rstrip('0'))
+        return None if val_n < -e else n // 10**-e
+
+def _sqrt_nearest(n, a):
+    """Closest integer to the square root of the positive integer n.  a is
+    an initial approximation to the square root.  Any positive integer
+    will do for a, but the closer a is to the square root of n the
+    faster convergence will be.
+
+    """
+    if n <= 0 or a <= 0:
+        raise ValueError("Both arguments to _sqrt_nearest should be positive.")
+
+    b=0
+    while a != b:
+        b, a = a, a--n//a>>1
+    return a
+
+def _rshift_nearest(x, shift):
+    """Given an integer x and a nonnegative integer shift, return closest
+    integer to x / 2**shift; use round-to-even in case of a tie.
+
+    """
+    b, q = 1 << shift, x >> shift
+    return q + (2*(x & (b-1)) + (q&1) > b)
+
+def _div_nearest(a, b):
+    """Closest integer to a/b, a and b positive integers; rounds to even
+    in the case of a tie.
+
+    """
+    q, r = divmod(a, b)
+    return q + (2*r + (q&1) > b)
+
+def _ilog(x, M, L = 8):
+    """Integer approximation to M*log(x/M), with absolute error boundable
+    in terms only of x/M.
+
+    Given positive integers x and M, return an integer approximation to
+    M * log(x/M).  For L = 8 and 0.1 <= x/M <= 10 the difference
+    between the approximation and the exact result is at most 22.  For
+    L = 8 and 1.0 <= x/M <= 10.0 the difference is at most 15.  In
+    both cases these are upper bounds on the error; it will usually be
+    much smaller."""
+
+    # The basic algorithm is the following: let log1p be the function
+    # log1p(x) = log(1+x).  Then log(x/M) = log1p((x-M)/M).  We use
+    # the reduction
+    #
+    #    log1p(y) = 2*log1p(y/(1+sqrt(1+y)))
+    #
+    # repeatedly until the argument to log1p is small (< 2**-L in
+    # absolute value).  For small y we can use the Taylor series
+    # expansion
+    #
+    #    log1p(y) ~ y - y**2/2 + y**3/3 - ... - (-y)**T/T
+    #
+    # truncating at T such that y**T is small enough.  The whole
+    # computation is carried out in a form of fixed-point arithmetic,
+    # with a real number z being represented by an integer
+    # approximation to z*M.  To avoid loss of precision, the y below
+    # is actually an integer approximation to 2**R*y*M, where R is the
+    # number of reductions performed so far.
+
+    y = x-M
+    # argument reduction; R = number of reductions performed
+    R = 0
+    while (R <= L and abs(y) << L-R >= M or
+           R > L and abs(y) >> R-L >= M):
+        y = _div_nearest((M*y) << 1,
+                         M + _sqrt_nearest(M*(M+_rshift_nearest(y, R)), M))
+        R += 1
+
+    # Taylor series with T terms
+    T = -int(-10*len(str(M))//(3*L))
+    yshift = _rshift_nearest(y, R)
+    w = _div_nearest(M, T)
+    for k in range(T-1, 0, -1):
+        w = _div_nearest(M, k) - _div_nearest(yshift*w, M)
+
+    return _div_nearest(w*y, M)
+
+def _dlog10(c, e, p):
+    """Given integers c, e and p with c > 0, p >= 0, compute an integer
+    approximation to 10**p * log10(c*10**e), with an absolute error of
+    at most 1.  Assumes that c*10**e is not exactly 1."""
+
+    # increase precision by 2; compensate for this by dividing
+    # final result by 100
+    p += 2
+
+    # write c*10**e as d*10**f with either:
+    #   f >= 0 and 1 <= d <= 10, or
+    #   f <= 0 and 0.1 <= d <= 1.
+    # Thus for c*10**e close to 1, f = 0
+    l = len(str(c))
+    f = e+l - (e+l >= 1)
+
+    if p > 0:
+        M = 10**p
+        k = e+p-f
+        if k >= 0:
+            c *= 10**k
+        else:
+            c = _div_nearest(c, 10**-k)
+
+        log_d = _ilog(c, M) # error < 5 + 22 = 27
+        log_10 = _log10_digits(p) # error < 1
+        log_d = _div_nearest(log_d*M, log_10)
+        log_tenpower = f*M # exact
+    else:
+        log_d = 0  # error < 2.31
+        log_tenpower = _div_nearest(f, 10**-p) # error < 0.5
+
+    return _div_nearest(log_tenpower+log_d, 100)
+
+def _dlog(c, e, p):
+    """Given integers c, e and p with c > 0, compute an integer
+    approximation to 10**p * log(c*10**e), with an absolute error of
+    at most 1.  Assumes that c*10**e is not exactly 1."""
+
+    # Increase precision by 2. The precision increase is compensated
+    # for at the end with a division by 100.
+    p += 2
+
+    # rewrite c*10**e as d*10**f with either f >= 0 and 1 <= d <= 10,
+    # or f <= 0 and 0.1 <= d <= 1.  Then we can compute 10**p * log(c*10**e)
+    # as 10**p * log(d) + 10**p*f * log(10).
+    l = len(str(c))
+    f = e+l - (e+l >= 1)
+
+    # compute approximation to 10**p*log(d), with error < 27
+    if p > 0:
+        k = e+p-f
+        if k >= 0:
+            c *= 10**k
+        else:
+            c = _div_nearest(c, 10**-k)  # error of <= 0.5 in c
+
+        # _ilog magnifies existing error in c by a factor of at most 10
+        log_d = _ilog(c, 10**p) # error < 5 + 22 = 27
+    else:
+        # p <= 0: just approximate the whole thing by 0; error < 2.31
+        log_d = 0
+
+    # compute approximation to f*10**p*log(10), with error < 11.
+    if f:
+        extra = len(str(abs(f)))-1
+        if p + extra >= 0:
+            # error in f * _log10_digits(p+extra) < |f| * 1 = |f|
+            # after division, error < |f|/10**extra + 0.5 < 10 + 0.5 < 11
+            f_log_ten = _div_nearest(f*_log10_digits(p+extra), 10**extra)
+        else:
+            f_log_ten = 0
+    else:
+        f_log_ten = 0
+
+    # error in sum < 11+27 = 38; error after division < 0.38 + 0.5 < 1
+    return _div_nearest(f_log_ten + log_d, 100)
+
+class _Log10Memoize(object):
+    """Class to compute, store, and allow retrieval of, digits of the
+    constant log(10) = 2.302585....  This constant is needed by
+    Decimal.ln, Decimal.log10, Decimal.exp and Decimal.__pow__."""
+    def __init__(self):
+        self.digits = "23025850929940456840179914546843642076011014886"
+
+    def getdigits(self, p):
+        """Given an integer p >= 0, return floor(10**p)*log(10).
+
+        For example, self.getdigits(3) returns 2302.
+        """
+        # digits are stored as a string, for quick conversion to
+        # integer in the case that we've already computed enough
+        # digits; the stored digits should always be correct
+        # (truncated, not rounded to nearest).
+        if p < 0:
+            raise ValueError("p should be nonnegative")
+
+        if p >= len(self.digits):
+            # compute p+3, p+6, p+9, ... digits; continue until at
+            # least one of the extra digits is nonzero
+            extra = 3
+            while True:
+                # compute p+extra digits, correct to within 1ulp
+                M = 10**(p+extra+2)
+                digits = str(_div_nearest(_ilog(10*M, M), 100))
+                if digits[-extra:] != '0'*extra:
+                    break
+                extra += 3
+            # keep all reliable digits so far; remove trailing zeros
+            # and next nonzero digit
+            self.digits = digits.rstrip('0')[:-1]
+        return int(self.digits[:p+1])
+
+_log10_digits = _Log10Memoize().getdigits
+
+def _iexp(x, M, L=8):
+    """Given integers x and M, M > 0, such that x/M is small in absolute
+    value, compute an integer approximation to M*exp(x/M).  For 0 <=
+    x/M <= 2.4, the absolute error in the result is bounded by 60 (and
+    is usually much smaller)."""
+
+    # Algorithm: to compute exp(z) for a real number z, first divide z
+    # by a suitable power R of 2 so that |z/2**R| < 2**-L.  Then
+    # compute expm1(z/2**R) = exp(z/2**R) - 1 using the usual Taylor
+    # series
+    #
+    #     expm1(x) = x + x**2/2! + x**3/3! + ...
+    #
+    # Now use the identity
+    #
+    #     expm1(2x) = expm1(x)*(expm1(x)+2)
+    #
+    # R times to compute the sequence expm1(z/2**R),
+    # expm1(z/2**(R-1)), ... , exp(z/2), exp(z).
+
+    # Find R such that x/2**R/M <= 2**-L
+    R = _nbits((x<<L)//M)
+
+    # Taylor series.  (2**L)**T > M
+    T = -int(-10*len(str(M))//(3*L))
+    y = _div_nearest(x, T)
+    Mshift = M<<R
+    for i in range(T-1, 0, -1):
+        y = _div_nearest(x*(Mshift + y), Mshift * i)
+
+    # Expansion
+    for k in range(R-1, -1, -1):
+        Mshift = M<<(k+2)
+        y = _div_nearest(y*(y+Mshift), Mshift)
+
+    return M+y
+
+def _dexp(c, e, p):
+    """Compute an approximation to exp(c*10**e), with p decimal places of
+    precision.
+
+    Returns integers d, f such that:
+
+      10**(p-1) <= d <= 10**p, and
+      (d-1)*10**f < exp(c*10**e) < (d+1)*10**f
+
+    In other words, d*10**f is an approximation to exp(c*10**e) with p
+    digits of precision, and with an error in d of at most 1.  This is
+    almost, but not quite, the same as the error being < 1ulp: when d
+    = 10**(p-1) the error could be up to 10 ulp."""
+
+    # we'll call iexp with M = 10**(p+2), giving p+3 digits of precision
+    p += 2
+
+    # compute log(10) with extra precision = adjusted exponent of c*10**e
+    extra = max(0, e + len(str(c)) - 1)
+    q = p + extra
+
+    # compute quotient c*10**e/(log(10)) = c*10**(e+q)/(log(10)*10**q),
+    # rounding down
+    shift = e+q
+    if shift >= 0:
+        cshift = c*10**shift
+    else:
+        cshift = c//10**-shift
+    quot, rem = divmod(cshift, _log10_digits(q))
+
+    # reduce remainder back to original precision
+    rem = _div_nearest(rem, 10**extra)
+
+    # error in result of _iexp < 120;  error after division < 0.62
+    return _div_nearest(_iexp(rem, 10**p), 1000), quot - p + 3
+
+def _dpower(xc, xe, yc, ye, p):
+    """Given integers xc, xe, yc and ye representing Decimals x = xc*10**xe and
+    y = yc*10**ye, compute x**y.  Returns a pair of integers (c, e) such that:
+
+      10**(p-1) <= c <= 10**p, and
+      (c-1)*10**e < x**y < (c+1)*10**e
+
+    in other words, c*10**e is an approximation to x**y with p digits
+    of precision, and with an error in c of at most 1.  (This is
+    almost, but not quite, the same as the error being < 1ulp: when c
+    == 10**(p-1) we can only guarantee error < 10ulp.)
+
+    We assume that: x is positive and not equal to 1, and y is nonzero.
+    """
+
+    # Find b such that 10**(b-1) <= |y| <= 10**b
+    b = len(str(abs(yc))) + ye
+
+    # log(x) = lxc*10**(-p-b-1), to p+b+1 places after the decimal point
+    lxc = _dlog(xc, xe, p+b+1)
+
+    # compute product y*log(x) = yc*lxc*10**(-p-b-1+ye) = pc*10**(-p-1)
+    shift = ye-b
+    if shift >= 0:
+        pc = lxc*yc*10**shift
+    else:
+        pc = _div_nearest(lxc*yc, 10**-shift)
+
+    if pc == 0:
+        # we prefer a result that isn't exactly 1; this makes it
+        # easier to compute a correctly rounded result in __pow__
+        if ((len(str(xc)) + xe >= 1) == (yc > 0)): # if x**y > 1:
+            coeff, exp = 10**(p-1)+1, 1-p
+        else:
+            coeff, exp = 10**p-1, -p
+    else:
+        coeff, exp = _dexp(pc, -(p+1), p+1)
+        coeff = _div_nearest(coeff, 10)
+        exp += 1
+
+    return coeff, exp
+
+def _log10_lb(c, correction = {
+        '1': 100, '2': 70, '3': 53, '4': 40, '5': 31,
+        '6': 23, '7': 16, '8': 10, '9': 5}):
+    """Compute a lower bound for 100*log10(c) for a positive integer c."""
+    if c <= 0:
+        raise ValueError("The argument to _log10_lb should be nonnegative.")
+    str_c = str(c)
+    return 100*len(str_c) - correction[str_c[0]]
+
+##### Helper Functions ####################################################
+
+def _convert_other(other, raiseit=False, allow_float=False):
+    """Convert other to Decimal.
+
+    Verifies that it's ok to use in an implicit construction.
+    If allow_float is true, allow conversion from float;  this
+    is used in the comparison methods (__eq__ and friends).
+
+    """
+    if isinstance(other, Decimal):
+        return other
+    if isinstance(other, int):
+        return Decimal(other)
+    if allow_float and isinstance(other, float):
+        return Decimal.from_float(other)
+
+    if raiseit:
+        raise TypeError("Unable to convert %s to Decimal" % other)
+    return NotImplemented
+
+def _convert_for_comparison(self, other, equality_op=False):
+    """Given a Decimal instance self and a Python object other, return
+    a pair (s, o) of Decimal instances such that "s op o" is
+    equivalent to "self op other" for any of the 6 comparison
+    operators "op".
+
+    """
+    if isinstance(other, Decimal):
+        return self, other
+
+    # Comparison with a Rational instance (also includes integers):
+    # self op n/d <=> self*d op n (for n and d integers, d positive).
+    # A NaN or infinity can be left unchanged without affecting the
+    # comparison result.
+    if isinstance(other, _numbers.Rational):
+        if not self._is_special:
+            self = _dec_from_triple(self._sign,
+                                    str(int(self._int) * other.denominator),
+                                    self._exp)
+        return self, Decimal(other.numerator)
+
+    # Comparisons with float and complex types.  == and != comparisons
+    # with complex numbers should succeed, returning either True or False
+    # as appropriate.  Other comparisons return NotImplemented.
+    if equality_op and isinstance(other, _numbers.Complex) and other.imag == 0:
+        other = other.real
+    if isinstance(other, float):
+        context = getcontext()
+        if equality_op:
+            context.flags[FloatOperation] = 1
+        else:
+            context._raise_error(FloatOperation,
+                "strict semantics for mixing floats and Decimals are enabled")
+        return self, Decimal.from_float(other)
+    return NotImplemented, NotImplemented
+
+
+##### Setup Specific Contexts ############################################
+
+# The default context prototype used by Context()
+# Is mutable, so that new contexts can have different default values
+
+DefaultContext = Context(
+        prec=28, rounding=ROUND_HALF_EVEN,
+        traps=[DivisionByZero, Overflow, InvalidOperation],
+        flags=[],
+        Emax=999999,
+        Emin=-999999,
+        capitals=1,
+        clamp=0
+)
+
+# Pre-made alternate contexts offered by the specification
+# Don't change these; the user should be able to select these
+# contexts and be able to reproduce results from other implementations
+# of the spec.
+
+BasicContext = Context(
+        prec=9, rounding=ROUND_HALF_UP,
+        traps=[DivisionByZero, Overflow, InvalidOperation, Clamped, Underflow],
+        flags=[],
+)
+
+ExtendedContext = Context(
+        prec=9, rounding=ROUND_HALF_EVEN,
+        traps=[],
+        flags=[],
+)
+
+
+##### crud for parsing strings #############################################
+#
+# Regular expression used for parsing numeric strings.  Additional
+# comments:
+#
+# 1. Uncomment the two '\s*' lines to allow leading and/or trailing
+# whitespace.  But note that the specification disallows whitespace in
+# a numeric string.
+#
+# 2. For finite numbers (not infinities and NaNs) the body of the
+# number between the optional sign and the optional exponent must have
+# at least one decimal digit, possibly after the decimal point.  The
+# lookahead expression '(?=\d|\.\d)' checks this.
+
+import re
+_parser = re.compile(r"""        # A numeric string consists of:
+#    \s*
+    (?P<sign>[-+])?              # an optional sign, followed by either...
+    (
+        (?=\d|\.\d)              # ...a number (with at least one digit)
+        (?P<int>\d*)             # having a (possibly empty) integer part
+        (\.(?P<frac>\d*))?       # followed by an optional fractional part
+        (E(?P<exp>[-+]?\d+))?    # followed by an optional exponent, or...
+    |
+        Inf(inity)?              # ...an infinity, or...
+    |
+        (?P<signal>s)?           # ...an (optionally signaling)
+        NaN                      # NaN
+        (?P<diag>\d*)            # with (possibly empty) diagnostic info.
+    )
+#    \s*
+    \Z
+""", re.VERBOSE | re.IGNORECASE).match
+
+_all_zeros = re.compile('0*$').match
+_exact_half = re.compile('50*$').match
+
+##### PEP3101 support functions ##############################################
+# The functions in this section have little to do with the Decimal
+# class, and could potentially be reused or adapted for other pure
+# Python numeric classes that want to implement __format__
+#
+# A format specifier for Decimal looks like:
+#
+#   [[fill]align][sign][#][0][minimumwidth][,][.precision][type]
+
+_parse_format_specifier_regex = re.compile(r"""\A
+(?:
+   (?P<fill>.)?
+   (?P<align>[<>=^])
+)?
+(?P<sign>[-+ ])?
+(?P<alt>\#)?
+(?P<zeropad>0)?
+(?P<minimumwidth>(?!0)\d+)?
+(?P<thousands_sep>,)?
+(?:\.(?P<precision>0|(?!0)\d+))?
+(?P<type>[eEfFgGn%])?
+\Z
+""", re.VERBOSE|re.DOTALL)
+
+del re
+
+# The locale module is only needed for the 'n' format specifier.  The
+# rest of the PEP 3101 code functions quite happily without it, so we
+# don't care too much if locale isn't present.
+try:
+    import locale as _locale
+except ImportError:
+    pass
+
+def _parse_format_specifier(format_spec, _localeconv=None):
+    """Parse and validate a format specifier.
+
+    Turns a standard numeric format specifier into a dict, with the
+    following entries:
+
+      fill: fill character to pad field to minimum width
+      align: alignment type, either '<', '>', '=' or '^'
+      sign: either '+', '-' or ' '
+      minimumwidth: nonnegative integer giving minimum width
+      zeropad: boolean, indicating whether to pad with zeros
+      thousands_sep: string to use as thousands separator, or ''
+      grouping: grouping for thousands separators, in format
+        used by localeconv
+      decimal_point: string to use for decimal point
+      precision: nonnegative integer giving precision, or None
+      type: one of the characters 'eEfFgG%', or None
+
+    """
+    m = _parse_format_specifier_regex.match(format_spec)
+    if m is None:
+        raise ValueError("Invalid format specifier: " + format_spec)
+
+    # get the dictionary
+    format_dict = m.groupdict()
+
+    # zeropad; defaults for fill and alignment.  If zero padding
+    # is requested, the fill and align fields should be absent.
+    fill = format_dict['fill']
+    align = format_dict['align']
+    format_dict['zeropad'] = (format_dict['zeropad'] is not None)
+    if format_dict['zeropad']:
+        if fill is not None:
+            raise ValueError("Fill character conflicts with '0'"
+                             " in format specifier: " + format_spec)
+        if align is not None:
+            raise ValueError("Alignment conflicts with '0' in "
+                             "format specifier: " + format_spec)
+    format_dict['fill'] = fill or ' '
+    # PEP 3101 originally specified that the default alignment should
+    # be left;  it was later agreed that right-aligned makes more sense
+    # for numeric types.  See http://bugs.python.org/issue6857.
+    format_dict['align'] = align or '>'
+
+    # default sign handling: '-' for negative, '' for positive
+    if format_dict['sign'] is None:
+        format_dict['sign'] = '-'
+
+    # minimumwidth defaults to 0; precision remains None if not given
+    format_dict['minimumwidth'] = int(format_dict['minimumwidth'] or '0')
+    if format_dict['precision'] is not None:
+        format_dict['precision'] = int(format_dict['precision'])
+
+    # if format type is 'g' or 'G' then a precision of 0 makes little
+    # sense; convert it to 1.  Same if format type is unspecified.
+    if format_dict['precision'] == 0:
+        if format_dict['type'] is None or format_dict['type'] in 'gGn':
+            format_dict['precision'] = 1
+
+    # determine thousands separator, grouping, and decimal separator, and
+    # add appropriate entries to format_dict
+    if format_dict['type'] == 'n':
+        # apart from separators, 'n' behaves just like 'g'
+        format_dict['type'] = 'g'
+        if _localeconv is None:
+            _localeconv = _locale.localeconv()
+        if format_dict['thousands_sep'] is not None:
+            raise ValueError("Explicit thousands separator conflicts with "
+                             "'n' type in format specifier: " + format_spec)
+        format_dict['thousands_sep'] = _localeconv['thousands_sep']
+        format_dict['grouping'] = _localeconv['grouping']
+        format_dict['decimal_point'] = _localeconv['decimal_point']
+    else:
+        if format_dict['thousands_sep'] is None:
+            format_dict['thousands_sep'] = ''
+        format_dict['grouping'] = [3, 0]
+        format_dict['decimal_point'] = '.'
+
+    return format_dict
+
+def _format_align(sign, body, spec):
+    """Given an unpadded, non-aligned numeric string 'body' and sign
+    string 'sign', add padding and alignment conforming to the given
+    format specifier dictionary 'spec' (as produced by
+    parse_format_specifier).
+
+    """
+    # how much extra space do we have to play with?
+    minimumwidth = spec['minimumwidth']
+    fill = spec['fill']
+    padding = fill*(minimumwidth - len(sign) - len(body))
+
+    align = spec['align']
+    if align == '<':
+        result = sign + body + padding
+    elif align == '>':
+        result = padding + sign + body
+    elif align == '=':
+        result = sign + padding + body
+    elif align == '^':
+        half = len(padding)//2
+        result = padding[:half] + sign + body + padding[half:]
+    else:
+        raise ValueError('Unrecognised alignment field')
+
+    return result
+
+def _group_lengths(grouping):
+    """Convert a localeconv-style grouping into a (possibly infinite)
+    iterable of integers representing group lengths.
+
+    """
+    # The result from localeconv()['grouping'], and the input to this
+    # function, should be a list of integers in one of the
+    # following three forms:
+    #
+    #   (1) an empty list, or
+    #   (2) nonempty list of positive integers + [0]
+    #   (3) list of positive integers + [locale.CHAR_MAX], or
+
+    from itertools import chain, repeat
+    if not grouping:
+        return []
+    elif grouping[-1] == 0 and len(grouping) >= 2:
+        return chain(grouping[:-1], repeat(grouping[-2]))
+    elif grouping[-1] == _locale.CHAR_MAX:
+        return grouping[:-1]
+    else:
+        raise ValueError('unrecognised format for grouping')
+
+def _insert_thousands_sep(digits, spec, min_width=1):
+    """Insert thousands separators into a digit string.
+
+    spec is a dictionary whose keys should include 'thousands_sep' and
+    'grouping'; typically it's the result of parsing the format
+    specifier using _parse_format_specifier.
+
+    The min_width keyword argument gives the minimum length of the
+    result, which will be padded on the left with zeros if necessary.
+
+    If necessary, the zero padding adds an extra '0' on the left to
+    avoid a leading thousands separator.  For example, inserting
+    commas every three digits in '123456', with min_width=8, gives
+    '0,123,456', even though that has length 9.
+
+    """
+
+    sep = spec['thousands_sep']
+    grouping = spec['grouping']
+
+    groups = []
+    for l in _group_lengths(grouping):
+        if l <= 0:
+            raise ValueError("group length should be positive")
+        # max(..., 1) forces at least 1 digit to the left of a separator
+        l = min(max(len(digits), min_width, 1), l)
+        groups.append('0'*(l - len(digits)) + digits[-l:])
+        digits = digits[:-l]
+        min_width -= l
+        if not digits and min_width <= 0:
+            break
+        min_width -= len(sep)
+    else:
+        l = max(len(digits), min_width, 1)
+        groups.append('0'*(l - len(digits)) + digits[-l:])
+    return sep.join(reversed(groups))
+
+def _format_sign(is_negative, spec):
+    """Determine sign character."""
+
+    if is_negative:
+        return '-'
+    elif spec['sign'] in ' +':
+        return spec['sign']
+    else:
+        return ''
+
+def _format_number(is_negative, intpart, fracpart, exp, spec):
+    """Format a number, given the following data:
+
+    is_negative: true if the number is negative, else false
+    intpart: string of digits that must appear before the decimal point
+    fracpart: string of digits that must come after the point
+    exp: exponent, as an integer
+    spec: dictionary resulting from parsing the format specifier
+
+    This function uses the information in spec to:
+      insert separators (decimal separator and thousands separators)
+      format the sign
+      format the exponent
+      add trailing '%' for the '%' type
+      zero-pad if necessary
+      fill and align if necessary
+    """
+
+    sign = _format_sign(is_negative, spec)
+
+    if fracpart or spec['alt']:
+        fracpart = spec['decimal_point'] + fracpart
+
+    if exp != 0 or spec['type'] in 'eE':
+        echar = {'E': 'E', 'e': 'e', 'G': 'E', 'g': 'e'}[spec['type']]
+        fracpart += "{0}{1:+}".format(echar, exp)
+    if spec['type'] == '%':
+        fracpart += '%'
+
+    if spec['zeropad']:
+        min_width = spec['minimumwidth'] - len(fracpart) - len(sign)
+    else:
+        min_width = 0
+    intpart = _insert_thousands_sep(intpart, spec, min_width)
+
+    return _format_align(sign, intpart+fracpart, spec)
+
+
+##### Useful Constants (internal use only) ################################
+
+# Reusable defaults
+_Infinity = Decimal('Inf')
+_NegativeInfinity = Decimal('-Inf')
+_NaN = Decimal('NaN')
+_Zero = Decimal(0)
+_One = Decimal(1)
+_NegativeOne = Decimal(-1)
+
+# _SignedInfinity[sign] is infinity w/ that sign
+_SignedInfinity = (_Infinity, _NegativeInfinity)
+
+# Constants related to the hash implementation;  hash(x) is based
+# on the reduction of x modulo _PyHASH_MODULUS
+_PyHASH_MODULUS = sys.hash_info.modulus
+# hash values to use for positive and negative infinities, and nans
+_PyHASH_INF = sys.hash_info.inf
+_PyHASH_NAN = sys.hash_info.nan
+
+# _PyHASH_10INV is the inverse of 10 modulo the prime _PyHASH_MODULUS
+_PyHASH_10INV = pow(10, _PyHASH_MODULUS - 2, _PyHASH_MODULUS)
+del sys
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index c0b5fd1..50ad9ff 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -6,11 +6,17 @@ import os
 import abc
 import codecs
 import errno
+import array
+import stat
 # Import _thread instead of threading to reduce startup cost
 try:
     from _thread import allocate_lock as Lock
 except ImportError:
     from _dummy_thread import allocate_lock as Lock
+if os.name == 'win32':
+    from msvcrt import setmode as _setmode
+else:
+    _setmode = None
 
 import io
 from io import (__all__, SEEK_SET, SEEK_CUR, SEEK_END)
@@ -256,7 +262,7 @@ class OpenWrapper:
     Trick so that open won't become a bound method when stored
     as a class variable (as dbm.dumb does).
 
-    See initstdio() in Python/pythonrun.c.
+    See initstdio() in Python/pylifecycle.c.
     """
     __doc__ = DocDescriptor()
 
@@ -662,16 +668,33 @@ class BufferedIOBase(IOBase):
         Raises BlockingIOError if the underlying raw stream has no
         data at the moment.
         """
-        # XXX This ought to work with anything that supports the buffer API
-        data = self.read(len(b))
+
+        return self._readinto(b, read1=False)
+
+    def readinto1(self, b):
+        """Read up to len(b) bytes into *b*, using at most one system call
+
+        Returns an int representing the number of bytes read (0 for EOF).
+
+        Raises BlockingIOError if the underlying raw stream has no
+        data at the moment.
+        """
+
+        return self._readinto(b, read1=True)
+
+    def _readinto(self, b, read1):
+        if not isinstance(b, memoryview):
+            b = memoryview(b)
+        b = b.cast('B')
+
+        if read1:
+            data = self.read1(len(b))
+        else:
+            data = self.read(len(b))
         n = len(data)
-        try:
-            b[:n] = data
-        except TypeError as err:
-            import array
-            if not isinstance(b, array.array):
-                raise err
-            b[:n] = array.array('b', data)
+
+        b[:n] = data
+
         return n
 
     def write(self, b):
@@ -790,13 +813,14 @@ class _BufferedIOMixin(BufferedIOBase):
                         .format(self.__class__.__name__))
 
     def __repr__(self):
-        clsname = self.__class__.__name__
+        modname = self.__class__.__module__
+        clsname = self.__class__.__qualname__
         try:
             name = self.name
         except Exception:
-            return "<_pyio.{0}>".format(clsname)
+            return "<{}.{}>".format(modname, clsname)
         else:
-            return "<_pyio.{0} name={1!r}>".format(clsname, name)
+            return "<{}.{} name={!r}>".format(modname, clsname, name)
 
     ### Lower-level APIs ###
 
@@ -993,10 +1017,7 @@ class BufferedReader(_BufferedIOMixin):
             current_size = 0
             while True:
                 # Read until EOF or until read() would block.
-                try:
-                    chunk = self.raw.read()
-                except InterruptedError:
-                    continue
+                chunk = self.raw.read()
                 if chunk in empty_values:
                     nodata_val = chunk
                     break
@@ -1015,10 +1036,7 @@ class BufferedReader(_BufferedIOMixin):
         chunks = [buf[pos:]]
         wanted = max(self.buffer_size, n)
         while avail < n:
-            try:
-                chunk = self.raw.read(wanted)
-            except InterruptedError:
-                continue
+            chunk = self.raw.read(wanted)
             if chunk in empty_values:
                 nodata_val = chunk
                 break
@@ -1047,12 +1065,7 @@ class BufferedReader(_BufferedIOMixin):
         have = len(self._read_buf) - self._read_pos
         if have < want or have <= 0:
             to_read = self.buffer_size - have
-            while True:
-                try:
-                    current = self.raw.read(to_read)
-                except InterruptedError:
-                    continue
-                break
+            current = self.raw.read(to_read)
             if current:
                 self._read_buf = self._read_buf[self._read_pos:] + current
                 self._read_pos = 0
@@ -1071,6 +1084,58 @@ class BufferedReader(_BufferedIOMixin):
             return self._read_unlocked(
                 min(size, len(self._read_buf) - self._read_pos))
 
+    # Implementing readinto() and readinto1() is not strictly necessary (we
+    # could rely on the base class that provides an implementation in terms of
+    # read() and read1()). We do it anyway to keep the _pyio implementation
+    # similar to the io implementation (which implements the methods for
+    # performance reasons).
+    def _readinto(self, buf, read1):
+        """Read data into *buf* with at most one system call."""
+
+        if len(buf) == 0:
+            return 0
+
+        # Need to create a memoryview object of type 'b', otherwise
+        # we may not be able to assign bytes to it, and slicing it
+        # would create a new object.
+        if not isinstance(buf, memoryview):
+            buf = memoryview(buf)
+        buf = buf.cast('B')
+
+        written = 0
+        with self._read_lock:
+            while written < len(buf):
+
+                # First try to read from internal buffer
+                avail = min(len(self._read_buf) - self._read_pos, len(buf))
+                if avail:
+                    buf[written:written+avail] = \
+                        self._read_buf[self._read_pos:self._read_pos+avail]
+                    self._read_pos += avail
+                    written += avail
+                    if written == len(buf):
+                        break
+
+                # If remaining space in callers buffer is larger than
+                # internal buffer, read directly into callers buffer
+                if len(buf) - written > self.buffer_size:
+                    n = self.raw.readinto(buf[written:])
+                    if not n:
+                        break # eof
+                    written += n
+
+                # Otherwise refill internal buffer - unless we're
+                # in read1 mode and already got some data
+                elif not (read1 and written):
+                    if not self._peek_unlocked(1):
+                        break # eof
+
+                # In readinto1 mode, return as soon as we have some data
+                if read1 and written:
+                    break
+
+        return written
+
     def tell(self):
         return _BufferedIOMixin.tell(self) - len(self._read_buf) + self._read_pos
 
@@ -1149,8 +1214,6 @@ class BufferedWriter(_BufferedIOMixin):
         while self._write_buf:
             try:
                 n = self.raw.write(self._write_buf)
-            except InterruptedError:
-                continue
             except BlockingIOError:
                 raise RuntimeError("self.raw should implement RawIOBase: it "
                                    "should not raise BlockingIOError")
@@ -1220,6 +1283,9 @@ class BufferedRWPair(BufferedIOBase):
     def read1(self, size):
         return self.reader.read1(size)
 
+    def readinto1(self, b):
+        return self.reader.readinto1(b)
+
     def readable(self):
         return self.reader.readable()
 
@@ -1304,6 +1370,10 @@ class BufferedRandom(BufferedWriter, BufferedReader):
         self.flush()
         return BufferedReader.read1(self, size)
 
+    def readinto1(self, b):
+        self.flush()
+        return BufferedReader.readinto1(self, b)
+
     def write(self, b):
         if self._read_buf:
             # Undo readahead
@@ -1313,6 +1383,345 @@ class BufferedRandom(BufferedWriter, BufferedReader):
         return BufferedWriter.write(self, b)
 
 
+class FileIO(RawIOBase):
+    _fd = -1
+    _created = False
+    _readable = False
+    _writable = False
+    _appending = False
+    _seekable = None
+    _closefd = True
+
+    def __init__(self, file, mode='r', closefd=True, opener=None):
+        """Open a file.  The mode can be 'r' (default), 'w', 'x' or 'a' for reading,
+        writing, exclusive creation or appending.  The file will be created if it
+        doesn't exist when opened for writing or appending; it will be truncated
+        when opened for writing.  A FileExistsError will be raised if it already
+        exists when opened for creating. Opening a file for creating implies
+        writing so this mode behaves in a similar way to 'w'. Add a '+' to the mode
+        to allow simultaneous reading and writing. A custom opener can be used by
+        passing a callable as *opener*. The underlying file descriptor for the file
+        object is then obtained by calling opener with (*name*, *flags*).
+        *opener* must return an open file descriptor (passing os.open as *opener*
+        results in functionality similar to passing None).
+        """
+        if self._fd >= 0:
+            # Have to close the existing file first.
+            try:
+                if self._closefd:
+                    os.close(self._fd)
+            finally:
+                self._fd = -1
+
+        if isinstance(file, float):
+            raise TypeError('integer argument expected, got float')
+        if isinstance(file, int):
+            fd = file
+            if fd < 0:
+                raise ValueError('negative file descriptor')
+        else:
+            fd = -1
+
+        if not isinstance(mode, str):
+            raise TypeError('invalid mode: %s' % (mode,))
+        if not set(mode) <= set('xrwab+'):
+            raise ValueError('invalid mode: %s' % (mode,))
+        if sum(c in 'rwax' for c in mode) != 1 or mode.count('+') > 1:
+            raise ValueError('Must have exactly one of create/read/write/append '
+                             'mode and at most one plus')
+
+        if 'x' in mode:
+            self._created = True
+            self._writable = True
+            flags = os.O_EXCL | os.O_CREAT
+        elif 'r' in mode:
+            self._readable = True
+            flags = 0
+        elif 'w' in mode:
+            self._writable = True
+            flags = os.O_CREAT | os.O_TRUNC
+        elif 'a' in mode:
+            self._writable = True
+            self._appending = True
+            flags = os.O_APPEND | os.O_CREAT
+
+        if '+' in mode:
+            self._readable = True
+            self._writable = True
+
+        if self._readable and self._writable:
+            flags |= os.O_RDWR
+        elif self._readable:
+            flags |= os.O_RDONLY
+        else:
+            flags |= os.O_WRONLY
+
+        flags |= getattr(os, 'O_BINARY', 0)
+
+        noinherit_flag = (getattr(os, 'O_NOINHERIT', 0) or
+                          getattr(os, 'O_CLOEXEC', 0))
+        flags |= noinherit_flag
+
+        owned_fd = None
+        try:
+            if fd < 0:
+                if not closefd:
+                    raise ValueError('Cannot use closefd=False with file name')
+                if opener is None:
+                    fd = os.open(file, flags, 0o666)
+                else:
+                    fd = opener(file, flags)
+                    if not isinstance(fd, int):
+                        raise TypeError('expected integer from opener')
+                    if fd < 0:
+                        raise OSError('Negative file descriptor')
+                owned_fd = fd
+                if not noinherit_flag:
+                    os.set_inheritable(fd, False)
+
+            self._closefd = closefd
+            fdfstat = os.fstat(fd)
+            try:
+                if stat.S_ISDIR(fdfstat.st_mode):
+                    raise IsADirectoryError(errno.EISDIR,
+                                            os.strerror(errno.EISDIR), file)
+            except AttributeError:
+                # Ignore the AttribueError if stat.S_ISDIR or errno.EISDIR
+                # don't exist.
+                pass
+            self._blksize = getattr(fdfstat, 'st_blksize', 0)
+            if self._blksize <= 1:
+                self._blksize = DEFAULT_BUFFER_SIZE
+
+            if _setmode:
+                # don't translate newlines (\r\n <=> \n)
+                _setmode(fd, os.O_BINARY)
+
+            self.name = file
+            if self._appending:
+                # For consistent behaviour, we explicitly seek to the
+                # end of file (otherwise, it might be done only on the
+                # first write()).
+                os.lseek(fd, 0, SEEK_END)
+        except:
+            if owned_fd is not None:
+                os.close(owned_fd)
+            raise
+        self._fd = fd
+
+    def __del__(self):
+        if self._fd >= 0 and self._closefd and not self.closed:
+            import warnings
+            warnings.warn('unclosed file %r' % (self,), ResourceWarning,
+                          stacklevel=2)
+            self.close()
+
+    def __getstate__(self):
+        raise TypeError("cannot serialize '%s' object", self.__class__.__name__)
+
+    def __repr__(self):
+        class_name = '%s.%s' % (self.__class__.__module__,
+                                self.__class__.__qualname__)
+        if self.closed:
+            return '<%s [closed]>' % class_name
+        try:
+            name = self.name
+        except AttributeError:
+            return ('<%s fd=%d mode=%r closefd=%r>' %
+                    (class_name, self._fd, self.mode, self._closefd))
+        else:
+            return ('<%s name=%r mode=%r closefd=%r>' %
+                    (class_name, name, self.mode, self._closefd))
+
+    def _checkReadable(self):
+        if not self._readable:
+            raise UnsupportedOperation('File not open for reading')
+
+    def _checkWritable(self, msg=None):
+        if not self._writable:
+            raise UnsupportedOperation('File not open for writing')
+
+    def read(self, size=None):
+        """Read at most size bytes, returned as bytes.
+
+        Only makes one system call, so less data may be returned than requested
+        In non-blocking mode, returns None if no data is available.
+        Return an empty bytes object at EOF.
+        """
+        self._checkClosed()
+        self._checkReadable()
+        if size is None or size < 0:
+            return self.readall()
+        try:
+            return os.read(self._fd, size)
+        except BlockingIOError:
+            return None
+
+    def readall(self):
+        """Read all data from the file, returned as bytes.
+
+        In non-blocking mode, returns as much as is immediately available,
+        or None if no data is available.  Return an empty bytes object at EOF.
+        """
+        self._checkClosed()
+        self._checkReadable()
+        bufsize = DEFAULT_BUFFER_SIZE
+        try:
+            pos = os.lseek(self._fd, 0, SEEK_CUR)
+            end = os.fstat(self._fd).st_size
+            if end >= pos:
+                bufsize = end - pos + 1
+        except OSError:
+            pass
+
+        result = bytearray()
+        while True:
+            if len(result) >= bufsize:
+                bufsize = len(result)
+                bufsize += max(bufsize, DEFAULT_BUFFER_SIZE)
+            n = bufsize - len(result)
+            try:
+                chunk = os.read(self._fd, n)
+            except BlockingIOError:
+                if result:
+                    break
+                return None
+            if not chunk: # reached the end of the file
+                break
+            result += chunk
+
+        return bytes(result)
+
+    def readinto(self, b):
+        """Same as RawIOBase.readinto()."""
+        m = memoryview(b).cast('B')
+        data = self.read(len(m))
+        n = len(data)
+        m[:n] = data
+        return n
+
+    def write(self, b):
+        """Write bytes b to file, return number written.
+
+        Only makes one system call, so not all of the data may be written.
+        The number of bytes actually written is returned.  In non-blocking mode,
+        returns None if the write would block.
+        """
+        self._checkClosed()
+        self._checkWritable()
+        try:
+            return os.write(self._fd, b)
+        except BlockingIOError:
+            return None
+
+    def seek(self, pos, whence=SEEK_SET):
+        """Move to new file position.
+
+        Argument offset is a byte count.  Optional argument whence defaults to
+        SEEK_SET or 0 (offset from start of file, offset should be >= 0); other values
+        are SEEK_CUR or 1 (move relative to current position, positive or negative),
+        and SEEK_END or 2 (move relative to end of file, usually negative, although
+        many platforms allow seeking beyond the end of a file).
+
+        Note that not all file objects are seekable.
+        """
+        if isinstance(pos, float):
+            raise TypeError('an integer is required')
+        self._checkClosed()
+        return os.lseek(self._fd, pos, whence)
+
+    def tell(self):
+        """tell() -> int.  Current file position.
+
+        Can raise OSError for non seekable files."""
+        self._checkClosed()
+        return os.lseek(self._fd, 0, SEEK_CUR)
+
+    def truncate(self, size=None):
+        """Truncate the file to at most size bytes.
+
+        Size defaults to the current file position, as returned by tell().
+        The current file position is changed to the value of size.
+        """
+        self._checkClosed()
+        self._checkWritable()
+        if size is None:
+            size = self.tell()
+        os.ftruncate(self._fd, size)
+        return size
+
+    def close(self):
+        """Close the file.
+
+        A closed file cannot be used for further I/O operations.  close() may be
+        called more than once without error.
+        """
+        if not self.closed:
+            try:
+                if self._closefd:
+                    os.close(self._fd)
+            finally:
+                super().close()
+
+    def seekable(self):
+        """True if file supports random-access."""
+        self._checkClosed()
+        if self._seekable is None:
+            try:
+                self.tell()
+            except OSError:
+                self._seekable = False
+            else:
+                self._seekable = True
+        return self._seekable
+
+    def readable(self):
+        """True if file was opened in a read mode."""
+        self._checkClosed()
+        return self._readable
+
+    def writable(self):
+        """True if file was opened in a write mode."""
+        self._checkClosed()
+        return self._writable
+
+    def fileno(self):
+        """Return the underlying file descriptor (an integer)."""
+        self._checkClosed()
+        return self._fd
+
+    def isatty(self):
+        """True if the file is connected to a TTY device."""
+        self._checkClosed()
+        return os.isatty(self._fd)
+
+    @property
+    def closefd(self):
+        """True if the file descriptor will be closed by close()."""
+        return self._closefd
+
+    @property
+    def mode(self):
+        """String giving the file mode"""
+        if self._created:
+            if self._readable:
+                return 'xb+'
+            else:
+                return 'xb'
+        elif self._appending:
+            if self._readable:
+                return 'ab+'
+            else:
+                return 'ab'
+        elif self._readable:
+            if self._writable:
+                return 'rb+'
+            else:
+                return 'rb'
+        else:
+            return 'wb'
+
+
 class TextIOBase(IOBase):
 
     """Base class for text I/O.
@@ -1566,7 +1975,8 @@ class TextIOWrapper(TextIOBase):
     #   - "chars_..." for integer variables that count decoded characters
 
     def __repr__(self):
-        result = "<_pyio.TextIOWrapper"
+        result = "<{}.{}".format(self.__class__.__module__,
+                                 self.__class__.__qualname__)
         try:
             name = self.name
         except Exception:
diff --git a/Lib/_strptime.py b/Lib/_strptime.py
index f76fff1..374923d 100644
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@@ -167,9 +167,9 @@ class LocaleTime(object):
             time.tzset()
         except AttributeError:
             pass
-        no_saving = frozenset(["utc", "gmt", time.tzname[0].lower()])
+        no_saving = frozenset({"utc", "gmt", time.tzname[0].lower()})
         if time.daylight:
-            has_saving = frozenset([time.tzname[1].lower()])
+            has_saving = frozenset({time.tzname[1].lower()})
         else:
             has_saving = frozenset()
         self.timezone = (no_saving, has_saving)
@@ -253,8 +253,8 @@ class TimeRE(dict):
         # format directives (%m, etc.).
         regex_chars = re_compile(r"([\\.^$*+?\(\){}\[\]|])")
         format = regex_chars.sub(r"\\\1", format)
-        whitespace_replacement = re_compile('\s+')
-        format = whitespace_replacement.sub('\s+', format)
+        whitespace_replacement = re_compile(r'\s+')
+        format = whitespace_replacement.sub(r'\\s+', format)
         while '%' in format:
             directive_index = format.index('%')+1
             processed_format = "%s%s%s" % (processed_format,
diff --git a/Lib/abc.py b/Lib/abc.py
index 0358a46..1cbf96a 100644
--- a/Lib/abc.py
+++ b/Lib/abc.py
@@ -168,7 +168,7 @@ class ABCMeta(type):
 
     def _dump_registry(cls, file=None):
         """Debug helper to print the ABC registry."""
-        print("Class: %s.%s" % (cls.__module__, cls.__name__), file=file)
+        print("Class: %s.%s" % (cls.__module__, cls.__qualname__), file=file)
         print("Inv.counter: %s" % ABCMeta._abc_invalidation_counter, file=file)
         for name in sorted(cls.__dict__.keys()):
             if name.startswith("_abc_"):
diff --git a/Lib/argparse.py b/Lib/argparse.py
index be276bb..9a06719 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1209,11 +1209,6 @@ class Namespace(_AttributeHolder):
             return NotImplemented
         return vars(self) == vars(other)
 
-    def __ne__(self, other):
-        if not isinstance(other, Namespace):
-            return NotImplemented
-        return not (self == other)
-
     def __contains__(self, key):
         return key in self.__dict__
 
@@ -1595,6 +1590,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
         - argument_default -- The default value for all arguments
         - conflict_handler -- String indicating how to handle conflicts
         - add_help -- Add a -h/-help option
+        - allow_abbrev -- Allow long options to be abbreviated unambiguously
     """
 
     def __init__(self,
@@ -1608,7 +1604,8 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
                  fromfile_prefix_chars=None,
                  argument_default=None,
                  conflict_handler='error',
-                 add_help=True):
+                 add_help=True,
+                 allow_abbrev=True):
 
         superinit = super(ArgumentParser, self).__init__
         superinit(description=description,
@@ -1626,6 +1623,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
         self.formatter_class = formatter_class
         self.fromfile_prefix_chars = fromfile_prefix_chars
         self.add_help = add_help
+        self.allow_abbrev = allow_abbrev
 
         add_group = self.add_argument_group
         self._positionals = add_group(_('positional arguments'))
@@ -2103,23 +2101,24 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
                 action = self._option_string_actions[option_string]
                 return action, option_string, explicit_arg
 
-        # search through all possible prefixes of the option string
-        # and all actions in the parser for possible interpretations
-        option_tuples = self._get_option_tuples(arg_string)
-
-        # if multiple actions match, the option string was ambiguous
-        if len(option_tuples) > 1:
-            options = ', '.join([option_string
-                for action, option_string, explicit_arg in option_tuples])
-            args = {'option': arg_string, 'matches': options}
-            msg = _('ambiguous option: %(option)s could match %(matches)s')
-            self.error(msg % args)
-
-        # if exactly one action matched, this segmentation is good,
-        # so return the parsed action
-        elif len(option_tuples) == 1:
-            option_tuple, = option_tuples
-            return option_tuple
+        if self.allow_abbrev:
+            # search through all possible prefixes of the option string
+            # and all actions in the parser for possible interpretations
+            option_tuples = self._get_option_tuples(arg_string)
+
+            # if multiple actions match, the option string was ambiguous
+            if len(option_tuples) > 1:
+                options = ', '.join([option_string
+                    for action, option_string, explicit_arg in option_tuples])
+                args = {'option': arg_string, 'matches': options}
+                msg = _('ambiguous option: %(option)s could match %(matches)s')
+                self.error(msg % args)
+
+            # if exactly one action matched, this segmentation is good,
+            # so return the parsed action
+            elif len(option_tuples) == 1:
+                option_tuple, = option_tuples
+                return option_tuple
 
         # if it was not found as an option, but it looks like a negative
         # number, it was meant to be positional
diff --git a/Lib/asynchat.py b/Lib/asynchat.py
index 14c152f..f728d1b 100644
--- a/Lib/asynchat.py
+++ b/Lib/asynchat.py
@@ -287,6 +287,9 @@ class simple_producer:
 
 class fifo:
     def __init__(self, list=None):
+        import warnings
+        warnings.warn('fifo class will be removed in Python 3.6',
+                      DeprecationWarning, stacklevel=2)
         if not list:
             self.list = deque()
         else:
diff --git a/Lib/asyncio/queues.py b/Lib/asyncio/queues.py
index ed11662..50543c8 100644
--- a/Lib/asyncio/queues.py
+++ b/Lib/asyncio/queues.py
@@ -1,7 +1,6 @@
 """Queues"""
 
-__all__ = ['Queue', 'PriorityQueue', 'LifoQueue', 'QueueFull', 'QueueEmpty',
-           'JoinableQueue']
+__all__ = ['Queue', 'PriorityQueue', 'LifoQueue', 'QueueFull', 'QueueEmpty']
 
 import collections
 import heapq
@@ -287,7 +286,3 @@ class LifoQueue(Queue):
 
     def _get(self):
         return self._queue.pop()
-
-
-JoinableQueue = Queue
-"""Deprecated alias for Queue."""
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
index 00a6396..3b51f0f 100644
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -57,8 +57,8 @@ from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, EINVAL, \
      ENOTCONN, ESHUTDOWN, EISCONN, EBADF, ECONNABORTED, EPIPE, EAGAIN, \
      errorcode
 
-_DISCONNECTED = frozenset((ECONNRESET, ENOTCONN, ESHUTDOWN, ECONNABORTED, EPIPE,
-                           EBADF))
+_DISCONNECTED = frozenset({ECONNRESET, ENOTCONN, ESHUTDOWN, ECONNABORTED, EPIPE,
+                           EBADF})
 
 try:
     socket_map
@@ -141,10 +141,7 @@ def poll(timeout=0.0, map=None):
             time.sleep(timeout)
             return
 
-        try:
-            r, w, e = select.select(r, w, e, timeout)
-        except InterruptedError:
-            return
+        r, w, e = select.select(r, w, e, timeout)
 
         for fd in r:
             obj = map.get(fd)
@@ -182,10 +179,8 @@ def poll2(timeout=0.0, map=None):
                 flags |= select.POLLOUT
             if flags:
                 pollster.register(fd, flags)
-        try:
-            r = pollster.poll(timeout)
-        except InterruptedError:
-            r = []
+
+        r = pollster.poll(timeout)
         for fd, flags in r:
             obj = map.get(fd)
             if obj is None:
@@ -220,7 +215,7 @@ class dispatcher:
     connecting = False
     closing = False
     addr = None
-    ignore_log_types = frozenset(['warning'])
+    ignore_log_types = frozenset({'warning'})
 
     def __init__(self, sock=None, map=None):
         if map is None:
@@ -255,7 +250,7 @@ class dispatcher:
             self.socket = None
 
     def __repr__(self):
-        status = [self.__class__.__module__+"."+self.__class__.__name__]
+        status = [self.__class__.__module__+"."+self.__class__.__qualname__]
         if self.accepting and self.addr:
             status.append('listening')
         elif self.connected:
@@ -404,20 +399,6 @@ class dispatcher:
                 if why.args[0] not in (ENOTCONN, EBADF):
                     raise
 
-    # cheap inheritance, used to pass all other attribute
-    # references to the underlying socket object.
-    def __getattr__(self, attr):
-        try:
-            retattr = getattr(self.socket, attr)
-        except AttributeError:
-            raise AttributeError("%s instance has no attribute '%s'"
-                                 %(self.__class__.__name__, attr))
-        else:
-            msg = "%(me)s.%(attr)s is deprecated; use %(me)s.socket.%(attr)s " \
-                  "instead" % {'me' : self.__class__.__name__, 'attr' : attr}
-            warnings.warn(msg, DeprecationWarning, stacklevel=2)
-            return retattr
-
     # log and log_info may be overridden to provide more sophisticated
     # logging and warning methods. In general, log is for 'hit' logging
     # and 'log_info' is for informational, warning and error logging.
@@ -604,8 +585,6 @@ def close_all(map=None, ignore_all=False):
 # Regardless, this is useful for pipes, and stdin/stdout...
 
 if os.name == 'posix':
-    import fcntl
-
     class file_wrapper:
         # Here we override just enough to make a file
         # look like a socket for the purposes of asyncore.
@@ -656,9 +635,7 @@ if os.name == 'posix':
                 pass
             self.set_file(fd)
             # set it to non-blocking mode
-            flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
-            flags = flags | os.O_NONBLOCK
-            fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+            os.set_blocking(fd, False)
 
         def set_file(self, fd):
             self.socket = file_wrapper(fd)
diff --git a/Lib/binhex.py b/Lib/binhex.py
index 8272d5c..56b5f85 100644
--- a/Lib/binhex.py
+++ b/Lib/binhex.py
@@ -235,14 +235,13 @@ def binhex(inp, out):
     finfo = getfileinfo(inp)
     ofp = BinHex(finfo, out)
 
-    ifp = io.open(inp, 'rb')
-    # XXXX Do textfile translation on non-mac systems
-    while True:
-        d = ifp.read(128000)
-        if not d: break
-        ofp.write(d)
-    ofp.close_data()
-    ifp.close()
+    with io.open(inp, 'rb') as ifp:
+        # XXXX Do textfile translation on non-mac systems
+        while True:
+            d = ifp.read(128000)
+            if not d: break
+            ofp.write(d)
+        ofp.close_data()
 
     ifp = openrsrc(inp, 'rb')
     while True:
@@ -459,13 +458,12 @@ def hexbin(inp, out):
     if not out:
         out = ifp.FName
 
-    ofp = io.open(out, 'wb')
-    # XXXX Do translation on non-mac systems
-    while True:
-        d = ifp.read(128000)
-        if not d: break
-        ofp.write(d)
-    ofp.close()
+    with io.open(out, 'wb') as ofp:
+        # XXXX Do translation on non-mac systems
+        while True:
+            d = ifp.read(128000)
+            if not d: break
+            ofp.write(d)
     ifp.close_data()
 
     d = ifp.read_rsrc(128000)
diff --git a/Lib/bz2.py b/Lib/bz2.py
index 6c5a60d..bc78c54 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -12,6 +12,7 @@ __author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>"
 from builtins import open as _builtin_open
 import io
 import warnings
+import _compression
 
 try:
     from threading import RLock
@@ -23,13 +24,11 @@ from _bz2 import BZ2Compressor, BZ2Decompressor
 
 _MODE_CLOSED   = 0
 _MODE_READ     = 1
-_MODE_READ_EOF = 2
+# Value 2 no longer used
 _MODE_WRITE    = 3
 
-_BUFFER_SIZE = 8192
 
-
-class BZ2File(io.BufferedIOBase):
+class BZ2File(_compression.BaseStream):
 
     """A file object providing transparent bzip2 (de)compression.
 
@@ -61,13 +60,11 @@ class BZ2File(io.BufferedIOBase):
         multiple compressed streams.
         """
         # This lock must be recursive, so that BufferedIOBase's
-        # readline(), readlines() and writelines() don't deadlock.
+        # writelines() does not deadlock.
         self._lock = RLock()
         self._fp = None
         self._closefp = False
         self._mode = _MODE_CLOSED
-        self._pos = 0
-        self._size = -1
 
         if buffering is not None:
             warnings.warn("Use of 'buffering' argument is deprecated",
@@ -79,9 +76,6 @@ class BZ2File(io.BufferedIOBase):
         if mode in ("", "r", "rb"):
             mode = "rb"
             mode_code = _MODE_READ
-            self._decompressor = BZ2Decompressor()
-            self._buffer = b""
-            self._buffer_offset = 0
         elif mode in ("w", "wb"):
             mode = "wb"
             mode_code = _MODE_WRITE
@@ -107,6 +101,13 @@ class BZ2File(io.BufferedIOBase):
         else:
             raise TypeError("filename must be a str or bytes object, or a file")
 
+        if self._mode == _MODE_READ:
+            raw = _compression.DecompressReader(self._fp,
+                BZ2Decompressor, trailing_error=OSError)
+            self._buffer = io.BufferedReader(raw)
+        else:
+            self._pos = 0
+
     def close(self):
         """Flush and close the file.
 
@@ -117,8 +118,8 @@ class BZ2File(io.BufferedIOBase):
             if self._mode == _MODE_CLOSED:
                 return
             try:
-                if self._mode in (_MODE_READ, _MODE_READ_EOF):
-                    self._decompressor = None
+                if self._mode == _MODE_READ:
+                    self._buffer.close()
                 elif self._mode == _MODE_WRITE:
                     self._fp.write(self._compressor.flush())
                     self._compressor = None
@@ -130,8 +131,7 @@ class BZ2File(io.BufferedIOBase):
                     self._fp = None
                     self._closefp = False
                     self._mode = _MODE_CLOSED
-                    self._buffer = b""
-                    self._buffer_offset = 0
+                    self._buffer = None
 
     @property
     def closed(self):
@@ -145,125 +145,18 @@ class BZ2File(io.BufferedIOBase):
 
     def seekable(self):
         """Return whether the file supports seeking."""
-        return self.readable() and self._fp.seekable()
+        return self.readable() and self._buffer.seekable()
 
     def readable(self):
         """Return whether the file was opened for reading."""
         self._check_not_closed()
-        return self._mode in (_MODE_READ, _MODE_READ_EOF)
+        return self._mode == _MODE_READ
 
     def writable(self):
         """Return whether the file was opened for writing."""
         self._check_not_closed()
         return self._mode == _MODE_WRITE
 
-    # Mode-checking helper functions.
-
-    def _check_not_closed(self):
-        if self.closed:
-            raise ValueError("I/O operation on closed file")
-
-    def _check_can_read(self):
-        if self._mode not in (_MODE_READ, _MODE_READ_EOF):
-            self._check_not_closed()
-            raise io.UnsupportedOperation("File not open for reading")
-
-    def _check_can_write(self):
-        if self._mode != _MODE_WRITE:
-            self._check_not_closed()
-            raise io.UnsupportedOperation("File not open for writing")
-
-    def _check_can_seek(self):
-        if self._mode not in (_MODE_READ, _MODE_READ_EOF):
-            self._check_not_closed()
-            raise io.UnsupportedOperation("Seeking is only supported "
-                                          "on files open for reading")
-        if not self._fp.seekable():
-            raise io.UnsupportedOperation("The underlying file object "
-                                          "does not support seeking")
-
-    # Fill the readahead buffer if it is empty. Returns False on EOF.
-    def _fill_buffer(self):
-        if self._mode == _MODE_READ_EOF:
-            return False
-        # Depending on the input data, our call to the decompressor may not
-        # return any data. In this case, try again after reading another block.
-        while self._buffer_offset == len(self._buffer):
-            rawblock = (self._decompressor.unused_data or
-                        self._fp.read(_BUFFER_SIZE))
-
-            if not rawblock:
-                if self._decompressor.eof:
-                    # End-of-stream marker and end of file. We're good.
-                    self._mode = _MODE_READ_EOF
-                    self._size = self._pos
-                    return False
-                else:
-                    # Problem - we were expecting more compressed data.
-                    raise EOFError("Compressed file ended before the "
-                                   "end-of-stream marker was reached")
-
-            if self._decompressor.eof:
-                # Continue to next stream.
-                self._decompressor = BZ2Decompressor()
-                try:
-                    self._buffer = self._decompressor.decompress(rawblock)
-                except OSError:
-                    # Trailing data isn't a valid bzip2 stream. We're done here.
-                    self._mode = _MODE_READ_EOF
-                    self._size = self._pos
-                    return False
-            else:
-                self._buffer = self._decompressor.decompress(rawblock)
-            self._buffer_offset = 0
-        return True
-
-    # Read data until EOF.
-    # If return_data is false, consume the data without returning it.
-    def _read_all(self, return_data=True):
-        # The loop assumes that _buffer_offset is 0. Ensure that this is true.
-        self._buffer = self._buffer[self._buffer_offset:]
-        self._buffer_offset = 0
-
-        blocks = []
-        while self._fill_buffer():
-            if return_data:
-                blocks.append(self._buffer)
-            self._pos += len(self._buffer)
-            self._buffer = b""
-        if return_data:
-            return b"".join(blocks)
-
-    # Read a block of up to n bytes.
-    # If return_data is false, consume the data without returning it.
-    def _read_block(self, n, return_data=True):
-        # If we have enough data buffered, return immediately.
-        end = self._buffer_offset + n
-        if end <= len(self._buffer):
-            data = self._buffer[self._buffer_offset : end]
-            self._buffer_offset = end
-            self._pos += len(data)
-            return data if return_data else None
-
-        # The loop assumes that _buffer_offset is 0. Ensure that this is true.
-        self._buffer = self._buffer[self._buffer_offset:]
-        self._buffer_offset = 0
-
-        blocks = []
-        while n > 0 and self._fill_buffer():
-            if n < len(self._buffer):
-                data = self._buffer[:n]
-                self._buffer_offset = n
-            else:
-                data = self._buffer
-                self._buffer = b""
-            if return_data:
-                blocks.append(data)
-            self._pos += len(data)
-            n -= len(data)
-        if return_data:
-            return b"".join(blocks)
-
     def peek(self, n=0):
         """Return buffered data without advancing the file position.
 
@@ -272,9 +165,10 @@ class BZ2File(io.BufferedIOBase):
         """
         with self._lock:
             self._check_can_read()
-            if not self._fill_buffer():
-                return b""
-            return self._buffer[self._buffer_offset:]
+            # Relies on the undocumented fact that BufferedReader.peek()
+            # always returns at least one byte (except at EOF), independent
+            # of the value of n
+            return self._buffer.peek(n)
 
     def read(self, size=-1):
         """Read up to size uncompressed bytes from the file.
@@ -284,47 +178,29 @@ class BZ2File(io.BufferedIOBase):
         """
         with self._lock:
             self._check_can_read()
-            if size == 0:
-                return b""
-            elif size < 0:
-                return self._read_all()
-            else:
-                return self._read_block(size)
+            return self._buffer.read(size)
 
     def read1(self, size=-1):
         """Read up to size uncompressed bytes, while trying to avoid
-        making multiple reads from the underlying stream.
+        making multiple reads from the underlying stream. Reads up to a
+        buffer's worth of data if size is negative.
 
         Returns b'' if the file is at EOF.
         """
-        # Usually, read1() calls _fp.read() at most once. However, sometimes
-        # this does not give enough data for the decompressor to make progress.
-        # In this case we make multiple reads, to avoid returning b"".
         with self._lock:
             self._check_can_read()
-            if (size == 0 or
-                # Only call _fill_buffer() if the buffer is actually empty.
-                # This gives a significant speedup if *size* is small.
-                (self._buffer_offset == len(self._buffer) and not self._fill_buffer())):
-                return b""
-            if size > 0:
-                data = self._buffer[self._buffer_offset :
-                                    self._buffer_offset + size]
-                self._buffer_offset += len(data)
-            else:
-                data = self._buffer[self._buffer_offset:]
-                self._buffer = b""
-                self._buffer_offset = 0
-            self._pos += len(data)
-            return data
+            if size < 0:
+                size = io.DEFAULT_BUFFER_SIZE
+            return self._buffer.read1(size)
 
     def readinto(self, b):
-        """Read up to len(b) bytes into b.
+        """Read bytes into b.
 
         Returns the number of bytes read (0 for EOF).
         """
         with self._lock:
-            return io.BufferedIOBase.readinto(self, b)
+            self._check_can_read()
+            return self._buffer.readinto(b)
 
     def readline(self, size=-1):
         """Read a line of uncompressed bytes from the file.
@@ -339,15 +215,7 @@ class BZ2File(io.BufferedIOBase):
             size = size.__index__()
         with self._lock:
             self._check_can_read()
-            # Shortcut for the common case - the whole line is in the buffer.
-            if size < 0:
-                end = self._buffer.find(b"\n", self._buffer_offset) + 1
-                if end > 0:
-                    line = self._buffer[self._buffer_offset : end]
-                    self._buffer_offset = end
-                    self._pos += len(line)
-                    return line
-            return io.BufferedIOBase.readline(self, size)
+            return self._buffer.readline(size)
 
     def readlines(self, size=-1):
         """Read a list of lines of uncompressed bytes from the file.
@@ -361,7 +229,8 @@ class BZ2File(io.BufferedIOBase):
                 raise TypeError("Integer argument expected")
             size = size.__index__()
         with self._lock:
-            return io.BufferedIOBase.readlines(self, size)
+            self._check_can_read()
+            return self._buffer.readlines(size)
 
     def write(self, data):
         """Write a byte string to the file.
@@ -386,18 +255,9 @@ class BZ2File(io.BufferedIOBase):
         Line separators are not added between the written byte strings.
         """
         with self._lock:
-            return io.BufferedIOBase.writelines(self, seq)
-
-    # Rewind the file to the beginning of the data stream.
-    def _rewind(self):
-        self._fp.seek(0, 0)
-        self._mode = _MODE_READ
-        self._pos = 0
-        self._decompressor = BZ2Decompressor()
-        self._buffer = b""
-        self._buffer_offset = 0
-
-    def seek(self, offset, whence=0):
+            return _compression.BaseStream.writelines(self, seq)
+
+    def seek(self, offset, whence=io.SEEK_SET):
         """Change the file position.
 
         The new position is specified by offset, relative to the
@@ -414,35 +274,14 @@ class BZ2File(io.BufferedIOBase):
         """
         with self._lock:
             self._check_can_seek()
-
-            # Recalculate offset as an absolute file position.
-            if whence == 0:
-                pass
-            elif whence == 1:
-                offset = self._pos + offset
-            elif whence == 2:
-                # Seeking relative to EOF - we need to know the file's size.
-                if self._size < 0:
-                    self._read_all(return_data=False)
-                offset = self._size + offset
-            else:
-                raise ValueError("Invalid value for whence: %s" % (whence,))
-
-            # Make it so that offset is the number of bytes to skip forward.
-            if offset < self._pos:
-                self._rewind()
-            else:
-                offset -= self._pos
-
-            # Read and discard data until we reach the desired position.
-            self._read_block(offset, return_data=False)
-
-            return self._pos
+            return self._buffer.seek(offset, whence)
 
     def tell(self):
         """Return the current file position."""
         with self._lock:
             self._check_not_closed()
+            if self._mode == _MODE_READ:
+                return self._buffer.tell()
             return self._pos
 
 
diff --git a/Lib/cgi.py b/Lib/cgi.py
index 6959c9e..4be28ba 100755
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -566,6 +566,12 @@ class FieldStorage:
         except AttributeError:
             pass
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.file.close()
+
     def __repr__(self):
         """Return a printable representation."""
         return "FieldStorage(%r, %r, %r)" % (
diff --git a/Lib/cgitb.py b/Lib/cgitb.py
index 6eb52e7..b291100 100644
--- a/Lib/cgitb.py
+++ b/Lib/cgitb.py
@@ -294,9 +294,8 @@ class Hook:
             (fd, path) = tempfile.mkstemp(suffix=suffix, dir=self.logdir)
 
             try:
-                file = os.fdopen(fd, 'w')
-                file.write(doc)
-                file.close()
+                with os.fdopen(fd, 'w') as file:
+                    file.write(doc)
                 msg = '%s contains the description of this error.' % path
             except:
                 msg = 'Tried to save traceback to %s, but failed.' % path
diff --git a/Lib/code.py b/Lib/code.py
index f8184b6..53244e3 100644
--- a/Lib/code.py
+++ b/Lib/code.py
@@ -7,6 +7,7 @@
 
 import sys
 import traceback
+import argparse
 from codeop import CommandCompiler, compile_command
 
 __all__ = ["InteractiveInterpreter", "InteractiveConsole", "interact",
@@ -136,25 +137,18 @@ class InteractiveInterpreter:
         The output is written by self.write(), below.
 
         """
+        sys.last_type, sys.last_value, last_tb = ei = sys.exc_info()
+        sys.last_traceback = last_tb
         try:
-            type, value, tb = sys.exc_info()
-            sys.last_type = type
-            sys.last_value = value
-            sys.last_traceback = tb
-            tblist = traceback.extract_tb(tb)
-            del tblist[:1]
-            lines = traceback.format_list(tblist)
-            if lines:
-                lines.insert(0, "Traceback (most recent call last):\n")
-            lines.extend(traceback.format_exception_only(type, value))
+            lines = traceback.format_exception(ei[0], ei[1], last_tb.tb_next)
+            if sys.excepthook is sys.__excepthook__:
+                self.write(''.join(lines))
+            else:
+                # If someone has set sys.excepthook, we let that take precedence
+                # over self.write
+                sys.excepthook(ei[0], ei[1], last_tb)
         finally:
-            tblist = tb = None
-        if sys.excepthook is sys.__excepthook__:
-            self.write(''.join(lines))
-        else:
-            # If someone has set sys.excepthook, we let that take precedence
-            # over self.write
-            sys.excepthook(type, value, tb)
+            last_tb = ei = None
 
     def write(self, data):
         """Write a string.
@@ -299,4 +293,12 @@ def interact(banner=None, readfunc=None, local=None):
 
 
 if __name__ == "__main__":
-    interact()
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-q', action='store_true',
+                       help="don't print version and copyright messages")
+    args = parser.parse_args()
+    if args.q or sys.flags.quiet:
+        banner = ''
+    else:
+        banner = None
+    interact(banner)
diff --git a/Lib/codecs.py b/Lib/codecs.py
index 66dd024..31e73bd 100644
--- a/Lib/codecs.py
+++ b/Lib/codecs.py
@@ -27,7 +27,8 @@ __all__ = ["register", "lookup", "open", "EncodedFile", "BOM", "BOM_BE",
            "getincrementaldecoder", "getreader", "getwriter",
            "encode", "decode", "iterencode", "iterdecode",
            "strict_errors", "ignore_errors", "replace_errors",
-           "xmlcharrefreplace_errors", "backslashreplace_errors",
+           "xmlcharrefreplace_errors",
+           "backslashreplace_errors", "namereplace_errors",
            "register_error", "lookup_error"]
 
 ### Constants
@@ -105,8 +106,8 @@ class CodecInfo(tuple):
         return self
 
     def __repr__(self):
-        return "<%s.%s object for encoding %s at 0x%x>" % \
-                (self.__class__.__module__, self.__class__.__name__,
+        return "<%s.%s object for encoding %s at %#x>" % \
+                (self.__class__.__module__, self.__class__.__qualname__,
                  self.name, id(self))
 
 class Codec:
@@ -126,7 +127,8 @@ class Codec:
          'surrogateescape' - replace with private code points U+DCnn.
          'xmlcharrefreplace' - Replace with the appropriate XML
                                character reference (only for encoding).
-         'backslashreplace'  - Replace with backslashed escape sequences
+         'backslashreplace'  - Replace with backslashed escape sequences.
+         'namereplace'       - Replace with \\N{...} escape sequences
                                (only for encoding).
 
         The set of allowed values can be extended via register_error.
@@ -358,7 +360,8 @@ class StreamWriter(Codec):
              'xmlcharrefreplace' - Replace with the appropriate XML
                                    character reference.
              'backslashreplace'  - Replace with backslashed escape
-                                   sequences (only for encoding).
+                                   sequences.
+             'namereplace'       - Replace with \\N{...} escape sequences.
 
             The set of allowed parameter values can be extended via
             register_error.
@@ -428,7 +431,8 @@ class StreamReader(Codec):
 
              'strict' - raise a ValueError (or a subclass)
              'ignore' - ignore the character and continue with the next
-             'replace'- replace with a suitable replacement character;
+             'replace'- replace with a suitable replacement character
+             'backslashreplace' - Replace with backslashed escape sequences;
 
             The set of allowed parameter values can be extended via
             register_error.
@@ -1080,6 +1084,7 @@ try:
     replace_errors = lookup_error("replace")
     xmlcharrefreplace_errors = lookup_error("xmlcharrefreplace")
     backslashreplace_errors = lookup_error("backslashreplace")
+    namereplace_errors = lookup_error("namereplace")
 except LookupError:
     # In --disable-unicode builds, these error handler are missing
     strict_errors = None
@@ -1087,6 +1092,7 @@ except LookupError:
     replace_errors = None
     xmlcharrefreplace_errors = None
     backslashreplace_errors = None
+    namereplace_errors = None
 
 # Tell modulefinder that using codecs probably needs the encodings
 # package
diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py
index 565ae86..9fd3532 100644
--- a/Lib/collections/__init__.py
+++ b/Lib/collections/__init__.py
@@ -16,10 +16,29 @@ from _weakref import proxy as _proxy
 from itertools import repeat as _repeat, chain as _chain, starmap as _starmap
 from reprlib import recursive_repr as _recursive_repr
 
+MutableSequence.register(deque)
+
 ################################################################################
 ### OrderedDict
 ################################################################################
 
+class _OrderedDictKeysView(KeysView):
+
+    def __reversed__(self):
+        yield from reversed(self._mapping)
+
+class _OrderedDictItemsView(ItemsView):
+
+    def __reversed__(self):
+        for key in reversed(self._mapping):
+            yield (key, self._mapping[key])
+
+class _OrderedDictValuesView(ValuesView):
+
+    def __reversed__(self):
+        for key in reversed(self._mapping):
+            yield self._mapping[key]
+
 class _Link(object):
     __slots__ = 'prev', 'next', 'key', '__weakref__'
 
@@ -83,6 +102,8 @@ class OrderedDict(dict):
         link_next = link.next
         link_prev.next = link_next
         link_next.prev = link_prev
+        link.prev = None
+        link.next = None
 
     def __iter__(self):
         'od.__iter__() <==> iter(od)'
@@ -166,9 +187,19 @@ class OrderedDict(dict):
         return size
 
     update = __update = MutableMapping.update
-    keys = MutableMapping.keys
-    values = MutableMapping.values
-    items = MutableMapping.items
+
+    def keys(self):
+        "D.keys() -> a set-like object providing a view on D's keys"
+        return _OrderedDictKeysView(self)
+
+    def items(self):
+        "D.items() -> a set-like object providing a view on D's items"
+        return _OrderedDictItemsView(self)
+
+    def values(self):
+        "D.values() -> an object providing a view on D's values"
+        return _OrderedDictValuesView(self)
+
     __ne__ = MutableMapping.__ne__
 
     __marker = object()
@@ -958,7 +989,6 @@ class UserList(MutableSequence):
     def __lt__(self, other): return self.data <  self.__cast(other)
     def __le__(self, other): return self.data <= self.__cast(other)
     def __eq__(self, other): return self.data == self.__cast(other)
-    def __ne__(self, other): return self.data != self.__cast(other)
     def __gt__(self, other): return self.data >  self.__cast(other)
     def __ge__(self, other): return self.data >= self.__cast(other)
     def __cast(self, other):
@@ -1035,10 +1065,6 @@ class UserString(Sequence):
         if isinstance(string, UserString):
             return self.data == string.data
         return self.data == string
-    def __ne__(self, string):
-        if isinstance(string, UserString):
-            return self.data != string.data
-        return self.data != string
     def __lt__(self, string):
         if isinstance(string, UserString):
             return self.data < string.data
diff --git a/Lib/compileall.py b/Lib/compileall.py
index d957ee5..aeaaf8e 100644
--- a/Lib/compileall.py
+++ b/Lib/compileall.py
@@ -1,4 +1,4 @@
-"""Module/script to byte-compile all .py files to .pyc (or .pyo) files.
+"""Module/script to byte-compile all .py files to .pyc files.
 
 When called as a script with arguments, this compiles the directories
 given as arguments recursively; the -l option prevents it from
@@ -16,32 +16,24 @@ import importlib.util
 import py_compile
 import struct
 
-__all__ = ["compile_dir","compile_file","compile_path"]
-
-def compile_dir(dir, maxlevels=10, ddir=None, force=False, rx=None,
-                quiet=False, legacy=False, optimize=-1):
-    """Byte-compile all modules in the given directory tree.
+try:
+    from concurrent.futures import ProcessPoolExecutor
+except ImportError:
+    ProcessPoolExecutor = None
+from functools import partial
 
-    Arguments (only dir is required):
+__all__ = ["compile_dir","compile_file","compile_path"]
 
-    dir:       the directory to byte-compile
-    maxlevels: maximum recursion level (default 10)
-    ddir:      the directory that will be prepended to the path to the
-               file as it is compiled into each byte-code file.
-    force:     if True, force compilation, even if timestamps are up-to-date
-    quiet:     if True, be quiet during compilation
-    legacy:    if True, produce legacy pyc paths instead of PEP 3147 paths
-    optimize:  optimization level or -1 for level of the interpreter
-    """
+def _walk_dir(dir, ddir=None, maxlevels=10, quiet=0):
     if not quiet:
         print('Listing {!r}...'.format(dir))
     try:
         names = os.listdir(dir)
     except OSError:
-        print("Can't list {!r}".format(dir))
+        if quiet < 2:
+            print("Can't list {!r}".format(dir))
         names = []
     names.sort()
-    success = 1
     for name in names:
         if name == '__pycache__':
             continue
@@ -51,17 +43,55 @@ def compile_dir(dir, maxlevels=10, ddir=None, force=False, rx=None,
         else:
             dfile = None
         if not os.path.isdir(fullname):
-            if not compile_file(fullname, ddir, force, rx, quiet,
-                                legacy, optimize):
-                success = 0
+            yield fullname
         elif (maxlevels > 0 and name != os.curdir and name != os.pardir and
               os.path.isdir(fullname) and not os.path.islink(fullname)):
-            if not compile_dir(fullname, maxlevels - 1, dfile, force, rx,
-                               quiet, legacy, optimize):
+            yield from _walk_dir(fullname, ddir=dfile,
+                                 maxlevels=maxlevels - 1, quiet=quiet)
+
+def compile_dir(dir, maxlevels=10, ddir=None, force=False, rx=None,
+                quiet=0, legacy=False, optimize=-1, workers=1):
+    """Byte-compile all modules in the given directory tree.
+
+    Arguments (only dir is required):
+
+    dir:       the directory to byte-compile
+    maxlevels: maximum recursion level (default 10)
+    ddir:      the directory that will be prepended to the path to the
+               file as it is compiled into each byte-code file.
+    force:     if True, force compilation, even if timestamps are up-to-date
+    quiet:     full output with False or 0, errors only with 1,
+               no output with 2
+    legacy:    if True, produce legacy pyc paths instead of PEP 3147 paths
+    optimize:  optimization level or -1 for level of the interpreter
+    workers:   maximum number of parallel workers
+    """
+    files = _walk_dir(dir, quiet=quiet, maxlevels=maxlevels,
+                      ddir=ddir)
+    success = 1
+    if workers is not None and workers != 1:
+        if workers < 0:
+            raise ValueError('workers must be greater or equal to 0')
+        if ProcessPoolExecutor is None:
+            raise NotImplementedError('multiprocessing support not available')
+
+        workers = workers or None
+        with ProcessPoolExecutor(max_workers=workers) as executor:
+            results = executor.map(partial(compile_file,
+                                           ddir=ddir, force=force,
+                                           rx=rx, quiet=quiet,
+                                           legacy=legacy,
+                                           optimize=optimize),
+                                   files)
+            success = min(results, default=1)
+    else:
+        for file in files:
+            if not compile_file(file, ddir, force, rx, quiet,
+                                legacy, optimize):
                 success = 0
     return success
 
-def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
+def compile_file(fullname, ddir=None, force=False, rx=None, quiet=0,
                  legacy=False, optimize=-1):
     """Byte-compile one file.
 
@@ -71,7 +101,8 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
     ddir:      if given, the directory name compiled in to the
                byte-code file.
     force:     if True, force compilation, even if timestamps are up-to-date
-    quiet:     if True, be quiet during compilation
+    quiet:     full output with False or 0, errors only with 1,
+               no output with 2
     legacy:    if True, produce legacy pyc paths instead of PEP 3147 paths
     optimize:  optimization level or -1 for level of the interpreter
     """
@@ -87,11 +118,12 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
             return success
     if os.path.isfile(fullname):
         if legacy:
-            cfile = fullname + ('c' if __debug__ else 'o')
+            cfile = fullname + 'c'
         else:
             if optimize >= 0:
+                opt = optimize if optimize >= 1 else ''
                 cfile = importlib.util.cache_from_source(
-                                fullname, debug_override=not optimize)
+                                fullname, optimization=opt)
             else:
                 cfile = importlib.util.cache_from_source(fullname)
             cache_dir = os.path.dirname(cfile)
@@ -114,7 +146,10 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
                 ok = py_compile.compile(fullname, cfile, dfile, True,
                                         optimize=optimize)
             except py_compile.PyCompileError as err:
-                if quiet:
+                success = 0
+                if quiet >= 2:
+                    return success
+                elif quiet:
                     print('*** Error compiling {!r}...'.format(fullname))
                 else:
                     print('*** ', end='')
@@ -123,20 +158,21 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
                                      errors='backslashreplace')
                 msg = msg.decode(sys.stdout.encoding)
                 print(msg)
-                success = 0
             except (SyntaxError, UnicodeError, OSError) as e:
-                if quiet:
+                success = 0
+                if quiet >= 2:
+                    return success
+                elif quiet:
                     print('*** Error compiling {!r}...'.format(fullname))
                 else:
                     print('*** ', end='')
                 print(e.__class__.__name__ + ':', e)
-                success = 0
             else:
                 if ok == 0:
                     success = 0
     return success
 
-def compile_path(skip_curdir=1, maxlevels=0, force=False, quiet=False,
+def compile_path(skip_curdir=1, maxlevels=0, force=False, quiet=0,
                  legacy=False, optimize=-1):
     """Byte-compile all module on sys.path.
 
@@ -145,14 +181,15 @@ def compile_path(skip_curdir=1, maxlevels=0, force=False, quiet=False,
     skip_curdir: if true, skip current directory (default True)
     maxlevels:   max recursion level (default 0)
     force: as for compile_dir() (default False)
-    quiet: as for compile_dir() (default False)
+    quiet: as for compile_dir() (default 0)
     legacy: as for compile_dir() (default False)
     optimize: as for compile_dir() (default -1)
     """
     success = 1
     for dir in sys.path:
         if (not dir or dir == os.curdir) and skip_curdir:
-            print('Skipping current directory')
+            if quiet < 2:
+                print('Skipping current directory')
         else:
             success = success and compile_dir(dir, maxlevels, None,
                                               force, quiet=quiet,
@@ -169,10 +206,15 @@ def main():
     parser.add_argument('-l', action='store_const', const=0,
                         default=10, dest='maxlevels',
                         help="don't recurse into subdirectories")
+    parser.add_argument('-r', type=int, dest='recursion',
+                        help=('control the maximum recursion level. '
+                              'if `-l` and `-r` options are specified, '
+                              'then `-r` takes precedence.'))
     parser.add_argument('-f', action='store_true', dest='force',
                         help='force rebuild even if timestamps are up to date')
-    parser.add_argument('-q', action='store_true', dest='quiet',
-                        help='output only error messages')
+    parser.add_argument('-q', action='count', dest='quiet', default=0,
+                        help='output only error messages; -qq will suppress '
+                             'the error messages as well.')
     parser.add_argument('-b', action='store_true', dest='legacy',
                         help='use legacy (pre-PEP3147) compiled file locations')
     parser.add_argument('-d', metavar='DESTDIR',  dest='ddir', default=None,
@@ -192,8 +234,10 @@ def main():
                         help=('zero or more file and directory names '
                               'to compile; if no arguments given, defaults '
                               'to the equivalent of -l sys.path'))
-    args = parser.parse_args()
+    parser.add_argument('-j', '--workers', default=1,
+                        type=int, help='Run compileall concurrently')
 
+    args = parser.parse_args()
     compile_dests = args.compile_dest
 
     if (args.ddir and (len(compile_dests) != 1
@@ -203,6 +247,12 @@ def main():
         import re
         args.rx = re.compile(args.rx)
 
+
+    if args.recursion is not None:
+        maxlevels = args.recursion
+    else:
+        maxlevels = args.maxlevels
+
     # if flist is provided then load it
     if args.flist:
         try:
@@ -210,9 +260,13 @@ def main():
                 for line in f:
                     compile_dests.append(line.strip())
         except OSError:
-            print("Error reading file list {}".format(args.flist))
+            if args.quiet < 2:
+                print("Error reading file list {}".format(args.flist))
             return False
 
+    if args.workers is not None:
+        args.workers = args.workers or None
+
     success = True
     try:
         if compile_dests:
@@ -222,16 +276,17 @@ def main():
                                         args.quiet, args.legacy):
                         success = False
                 else:
-                    if not compile_dir(dest, args.maxlevels, args.ddir,
+                    if not compile_dir(dest, maxlevels, args.ddir,
                                        args.force, args.rx, args.quiet,
-                                       args.legacy):
+                                       args.legacy, workers=args.workers):
                         success = False
             return success
         else:
             return compile_path(legacy=args.legacy, force=args.force,
                                 quiet=args.quiet)
     except KeyboardInterrupt:
-        print("\n[interrupted]")
+        if args.quiet < 2:
+            print("\n[interrupted]")
         return False
     return True
 
diff --git a/Lib/concurrent/futures/_base.py b/Lib/concurrent/futures/_base.py
index acd05d0..9e44713 100644
--- a/Lib/concurrent/futures/_base.py
+++ b/Lib/concurrent/futures/_base.py
@@ -302,17 +302,20 @@ class Future(object):
         with self._condition:
             if self._state == FINISHED:
                 if self._exception:
-                    return '<Future at %s state=%s raised %s>' % (
-                        hex(id(self)),
+                    return '<%s at %#x state=%s raised %s>' % (
+                        self.__class__.__name__,
+                        id(self),
                         _STATE_TO_DESCRIPTION_MAP[self._state],
                         self._exception.__class__.__name__)
                 else:
-                    return '<Future at %s state=%s returned %s>' % (
-                        hex(id(self)),
+                    return '<%s at %#x state=%s returned %s>' % (
+                        self.__class__.__name__,
+                        id(self),
                         _STATE_TO_DESCRIPTION_MAP[self._state],
                         self._result.__class__.__name__)
-            return '<Future at %s state=%s>' % (
-                    hex(id(self)),
+            return '<%s at %#x state=%s>' % (
+                    self.__class__.__name__,
+                    id(self),
                    _STATE_TO_DESCRIPTION_MAP[self._state])
 
     def cancel(self):
@@ -517,7 +520,7 @@ class Executor(object):
         """
         raise NotImplementedError()
 
-    def map(self, fn, *iterables, timeout=None):
+    def map(self, fn, *iterables, timeout=None, chunksize=1):
         """Returns a iterator equivalent to map(fn, iter).
 
         Args:
@@ -525,6 +528,10 @@ class Executor(object):
                 passed iterables.
             timeout: The maximum number of seconds to wait. If None, then there
                 is no limit on the wait time.
+            chunksize: The size of the chunks the iterable will be broken into
+                before being passed to a child process. This argument is only
+                used by ProcessPoolExecutor; it is ignored by
+                ThreadPoolExecutor.
 
         Returns:
             An iterator equivalent to: map(func, *iterables) but the calls may
diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py
index 07b5225..3dd6da1 100644
--- a/Lib/concurrent/futures/process.py
+++ b/Lib/concurrent/futures/process.py
@@ -55,6 +55,9 @@ from multiprocessing import SimpleQueue
 from multiprocessing.connection import wait
 import threading
 import weakref
+from functools import partial
+import itertools
+import traceback
 
 # Workers are created as daemon threads and processes. This is done to allow the
 # interpreter to exit when there are still idle processes in a
@@ -88,6 +91,27 @@ def _python_exit():
 # (Futures in the call queue cannot be cancelled).
 EXTRA_QUEUED_CALLS = 1
 
+# Hack to embed stringification of remote traceback in local traceback
+
+class _RemoteTraceback(Exception):
+    def __init__(self, tb):
+        self.tb = tb
+    def __str__(self):
+        return self.tb
+
+class _ExceptionWithTraceback:
+    def __init__(self, exc, tb):
+        tb = traceback.format_exception(type(exc), exc, tb)
+        tb = ''.join(tb)
+        self.exc = exc
+        self.tb = '\n"""\n%s"""' % tb
+    def __reduce__(self):
+        return _rebuild_exc, (self.exc, self.tb)
+
+def _rebuild_exc(exc, tb):
+    exc.__cause__ = _RemoteTraceback(tb)
+    return exc
+
 class _WorkItem(object):
     def __init__(self, future, fn, args, kwargs):
         self.future = future
@@ -108,6 +132,26 @@ class _CallItem(object):
         self.args = args
         self.kwargs = kwargs
 
+def _get_chunks(*iterables, chunksize):
+    """ Iterates over zip()ed iterables in chunks. """
+    it = zip(*iterables)
+    while True:
+        chunk = tuple(itertools.islice(it, chunksize))
+        if not chunk:
+            return
+        yield chunk
+
+def _process_chunk(fn, chunk):
+    """ Processes a chunk of an iterable passed to map.
+
+    Runs the function passed to map() on a chunk of the
+    iterable passed to map.
+
+    This function is run in a separate process.
+
+    """
+    return [fn(*args) for args in chunk]
+
 def _process_worker(call_queue, result_queue):
     """Evaluates calls from call_queue and places the results in result_queue.
 
@@ -130,8 +174,8 @@ def _process_worker(call_queue, result_queue):
         try:
             r = call_item.fn(*call_item.args, **call_item.kwargs)
         except BaseException as e:
-            result_queue.put(_ResultItem(call_item.work_id,
-                                         exception=e))
+            exc = _ExceptionWithTraceback(e, e.__traceback__)
+            result_queue.put(_ResultItem(call_item.work_id, exception=exc))
         else:
             result_queue.put(_ResultItem(call_item.work_id,
                                          result=r))
@@ -334,6 +378,9 @@ class ProcessPoolExecutor(_base.Executor):
         if max_workers is None:
             self._max_workers = os.cpu_count() or 1
         else:
+            if max_workers <= 0:
+                raise ValueError("max_workers must be greater than 0")
+
             self._max_workers = max_workers
 
         # Make the call queue slightly larger than the number of processes to
@@ -408,6 +455,35 @@ class ProcessPoolExecutor(_base.Executor):
             return f
     submit.__doc__ = _base.Executor.submit.__doc__
 
+    def map(self, fn, *iterables, timeout=None, chunksize=1):
+        """Returns a iterator equivalent to map(fn, iter).
+
+        Args:
+            fn: A callable that will take as many arguments as there are
+                passed iterables.
+            timeout: The maximum number of seconds to wait. If None, then there
+                is no limit on the wait time.
+            chunksize: If greater than one, the iterables will be chopped into
+                chunks of size chunksize and submitted to the process pool.
+                If set to one, the items in the list will be sent one at a time.
+
+        Returns:
+            An iterator equivalent to: map(func, *iterables) but the calls may
+            be evaluated out-of-order.
+
+        Raises:
+            TimeoutError: If the entire result iterator could not be generated
+                before the given timeout.
+            Exception: If fn(*args) raises for any values.
+        """
+        if chunksize < 1:
+            raise ValueError("chunksize must be >= 1.")
+
+        results = super().map(partial(_process_chunk, fn),
+                              _get_chunks(*iterables, chunksize=chunksize),
+                              timeout=timeout)
+        return itertools.chain.from_iterable(results)
+
     def shutdown(self, wait=True):
         with self._shutdown_lock:
             self._shutdown_thread = True
diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py
index f9beb0f..3ae442d 100644
--- a/Lib/concurrent/futures/thread.py
+++ b/Lib/concurrent/futures/thread.py
@@ -10,6 +10,7 @@ from concurrent.futures import _base
 import queue
 import threading
 import weakref
+import os
 
 # Workers are created as daemon threads. This is done to allow the interpreter
 # to exit when there are still idle threads in a ThreadPoolExecutor's thread
@@ -80,13 +81,20 @@ def _worker(executor_reference, work_queue):
         _base.LOGGER.critical('Exception in worker', exc_info=True)
 
 class ThreadPoolExecutor(_base.Executor):
-    def __init__(self, max_workers):
+    def __init__(self, max_workers=None):
         """Initializes a new ThreadPoolExecutor instance.
 
         Args:
             max_workers: The maximum number of threads that can be used to
                 execute the given calls.
         """
+        if max_workers is None:
+            # Use this number because ThreadPoolExecutor is often
+            # used to overlap I/O instead of CPU work.
+            max_workers = (os.cpu_count() or 1) * 5
+        if max_workers <= 0:
+            raise ValueError("max_workers must be greater than 0")
+
         self._max_workers = max_workers
         self._work_queue = queue.Queue()
         self._threads = set()
diff --git a/Lib/configparser.py b/Lib/configparser.py
index 4ee8307..ecd0660 100644
--- a/Lib/configparser.py
+++ b/Lib/configparser.py
@@ -17,7 +17,8 @@ ConfigParser -- responsible for parsing a list of
     __init__(defaults=None, dict_type=_default_dict, allow_no_value=False,
              delimiters=('=', ':'), comment_prefixes=('#', ';'),
              inline_comment_prefixes=None, strict=True,
-             empty_lines_in_values=True):
+             empty_lines_in_values=True, default_section='DEFAULT',
+             interpolation=<unset>, converters=<unset>):
         Create the parser. When `defaults' is given, it is initialized into the
         dictionary or intrinsic defaults. The keys must be strings, the values
         must be appropriate for %()s string interpolation.
@@ -47,6 +48,25 @@ ConfigParser -- responsible for parsing a list of
         When `allow_no_value' is True (default: False), options without
         values are accepted; the value presented for these is None.
 
+        When `default_section' is given, the name of the special section is
+        named accordingly. By default it is called ``"DEFAULT"`` but this can
+        be customized to point to any other valid section name. Its current
+        value can be retrieved using the ``parser_instance.default_section``
+        attribute and may be modified at runtime.
+
+        When `interpolation` is given, it should be an Interpolation subclass
+        instance. It will be used as the handler for option value
+        pre-processing when using getters. RawConfigParser object s don't do
+        any sort of interpolation, whereas ConfigParser uses an instance of
+        BasicInterpolation. The library also provides a ``zc.buildbot``
+        inspired ExtendedInterpolation implementation.
+
+        When `converters` is given, it should be a dictionary where each key
+        represents the name of a type converter and each value is a callable
+        implementing the conversion from string to the desired datatype. Every
+        converter gets its corresponding get*() method on the parser object and
+        section proxies.
+
     sections()
         Return all the configuration section names, sans DEFAULT.
 
@@ -129,9 +149,11 @@ import warnings
 
 __all__ = ["NoSectionError", "DuplicateOptionError", "DuplicateSectionError",
            "NoOptionError", "InterpolationError", "InterpolationDepthError",
-           "InterpolationSyntaxError", "ParsingError",
-           "MissingSectionHeaderError",
+           "InterpolationMissingOptionError", "InterpolationSyntaxError",
+           "ParsingError", "MissingSectionHeaderError",
            "ConfigParser", "SafeConfigParser", "RawConfigParser",
+           "Interpolation", "BasicInterpolation",  "ExtendedInterpolation",
+           "LegacyInterpolation", "SectionProxy", "ConverterMapping",
            "DEFAULTSECT", "MAX_INTERPOLATION_DEPTH"]
 
 DEFAULTSECT = "DEFAULT"
@@ -410,7 +432,7 @@ class BasicInterpolation(Interpolation):
                     v = map[var]
                 except KeyError:
                     raise InterpolationMissingOptionError(
-                        option, section, rest, var)
+                        option, section, rest, var) from None
                 if "%" in v:
                     self._interpolate_some(parser, option, accum, v,
                                            section, map, depth + 1)
@@ -482,7 +504,7 @@ class ExtendedInterpolation(Interpolation):
                             "More than one ':' found: %r" % (rest,))
                 except (KeyError, NoSectionError, NoOptionError):
                     raise InterpolationMissingOptionError(
-                        option, section, rest, ":".join(path))
+                        option, section, rest, ":".join(path)) from None
                 if "$" in v:
                     self._interpolate_some(parser, opt, accum, v, sect,
                                            dict(parser.items(sect, raw=True)),
@@ -515,7 +537,7 @@ class LegacyInterpolation(Interpolation):
                     value = value % vars
                 except KeyError as e:
                     raise InterpolationMissingOptionError(
-                        option, section, rawval, e.args[0])
+                        option, section, rawval, e.args[0]) from None
             else:
                 break
         if value and "%(" in value:
@@ -580,11 +602,12 @@ class RawConfigParser(MutableMapping):
                  comment_prefixes=('#', ';'), inline_comment_prefixes=None,
                  strict=True, empty_lines_in_values=True,
                  default_section=DEFAULTSECT,
-                 interpolation=_UNSET):
+                 interpolation=_UNSET, converters=_UNSET):
 
         self._dict = dict_type
         self._sections = self._dict()
         self._defaults = self._dict()
+        self._converters = ConverterMapping(self)
         self._proxies = self._dict()
         self._proxies[default_section] = SectionProxy(self, default_section)
         if defaults:
@@ -612,6 +635,8 @@ class RawConfigParser(MutableMapping):
             self._interpolation = self._DEFAULT_INTERPOLATION
         if self._interpolation is None:
             self._interpolation = Interpolation()
+        if converters is not _UNSET:
+            self._converters.update(converters)
 
     def defaults(self):
         return self._defaults
@@ -647,7 +672,7 @@ class RawConfigParser(MutableMapping):
         try:
             opts = self._sections[section].copy()
         except KeyError:
-            raise NoSectionError(section)
+            raise NoSectionError(section) from None
         opts.update(self._defaults)
         return list(opts.keys())
 
@@ -775,36 +800,31 @@ class RawConfigParser(MutableMapping):
     def _get(self, section, conv, option, **kwargs):
         return conv(self.get(section, option, **kwargs))
 
-    def getint(self, section, option, *, raw=False, vars=None,
-               fallback=_UNSET):
+    def _get_conv(self, section, option, conv, *, raw=False, vars=None,
+                  fallback=_UNSET, **kwargs):
         try:
-            return self._get(section, int, option, raw=raw, vars=vars)
+            return self._get(section, conv, option, raw=raw, vars=vars,
+                             **kwargs)
         except (NoSectionError, NoOptionError):
             if fallback is _UNSET:
                 raise
-            else:
-                return fallback
+            return fallback
+
+    # getint, getfloat and getboolean provided directly for backwards compat
+    def getint(self, section, option, *, raw=False, vars=None,
+               fallback=_UNSET, **kwargs):
+        return self._get_conv(section, option, int, raw=raw, vars=vars,
+                              fallback=fallback, **kwargs)
 
     def getfloat(self, section, option, *, raw=False, vars=None,
-                 fallback=_UNSET):
-        try:
-            return self._get(section, float, option, raw=raw, vars=vars)
-        except (NoSectionError, NoOptionError):
-            if fallback is _UNSET:
-                raise
-            else:
-                return fallback
+                 fallback=_UNSET, **kwargs):
+        return self._get_conv(section, option, float, raw=raw, vars=vars,
+                              fallback=fallback, **kwargs)
 
     def getboolean(self, section, option, *, raw=False, vars=None,
-                   fallback=_UNSET):
-        try:
-            return self._get(section, self._convert_to_boolean, option,
-                             raw=raw, vars=vars)
-        except (NoSectionError, NoOptionError):
-            if fallback is _UNSET:
-                raise
-            else:
-                return fallback
+                   fallback=_UNSET, **kwargs):
+        return self._get_conv(section, option, self._convert_to_boolean,
+                              raw=raw, vars=vars, fallback=fallback, **kwargs)
 
     def items(self, section=_UNSET, raw=False, vars=None):
         """Return a list of (name, value) tuples for each option in a section.
@@ -876,7 +896,7 @@ class RawConfigParser(MutableMapping):
             try:
                 sectdict = self._sections[section]
             except KeyError:
-                raise NoSectionError(section)
+                raise NoSectionError(section) from None
         sectdict[self.optionxform(option)] = value
 
     def write(self, fp, space_around_delimiters=True):
@@ -917,7 +937,7 @@ class RawConfigParser(MutableMapping):
             try:
                 sectdict = self._sections[section]
             except KeyError:
-                raise NoSectionError(section)
+                raise NoSectionError(section) from None
         option = self.optionxform(option)
         existed = option in sectdict
         if existed:
@@ -1154,6 +1174,10 @@ class RawConfigParser(MutableMapping):
             if not isinstance(value, str):
                 raise TypeError("option values must be strings")
 
+    @property
+    def converters(self):
+        return self._converters
+
 
 class ConfigParser(RawConfigParser):
     """ConfigParser implementing interpolation."""
@@ -1194,6 +1218,10 @@ class SectionProxy(MutableMapping):
         """Creates a view on a section of the specified `name` in `parser`."""
         self._parser = parser
         self._name = name
+        for conv in parser.converters:
+            key = 'get' + conv
+            getter = functools.partial(self.get, _impl=getattr(parser, key))
+            setattr(self, key, getter)
 
     def __repr__(self):
         return '<Section: {}>'.format(self._name)
@@ -1227,22 +1255,6 @@ class SectionProxy(MutableMapping):
         else:
             return self._parser.defaults()
 
-    def get(self, option, fallback=None, *, raw=False, vars=None):
-        return self._parser.get(self._name, option, raw=raw, vars=vars,
-                                fallback=fallback)
-
-    def getint(self, option, fallback=None, *, raw=False, vars=None):
-        return self._parser.getint(self._name, option, raw=raw, vars=vars,
-                                   fallback=fallback)
-
-    def getfloat(self, option, fallback=None, *, raw=False, vars=None):
-        return self._parser.getfloat(self._name, option, raw=raw, vars=vars,
-                                     fallback=fallback)
-
-    def getboolean(self, option, fallback=None, *, raw=False, vars=None):
-        return self._parser.getboolean(self._name, option, raw=raw, vars=vars,
-                                       fallback=fallback)
-
     @property
     def parser(self):
         # The parser object of the proxy is read-only.
@@ -1252,3 +1264,77 @@ class SectionProxy(MutableMapping):
     def name(self):
         # The name of the section on a proxy is read-only.
         return self._name
+
+    def get(self, option, fallback=None, *, raw=False, vars=None,
+            _impl=None, **kwargs):
+        """Get an option value.
+
+        Unless `fallback` is provided, `None` will be returned if the option
+        is not found.
+
+        """
+        # If `_impl` is provided, it should be a getter method on the parser
+        # object that provides the desired type conversion.
+        if not _impl:
+            _impl = self._parser.get
+        return _impl(self._name, option, raw=raw, vars=vars,
+                     fallback=fallback, **kwargs)
+
+
+class ConverterMapping(MutableMapping):
+    """Enables reuse of get*() methods between the parser and section proxies.
+
+    If a parser class implements a getter directly, the value for the given
+    key will be ``None``. The presence of the converter name here enables
+    section proxies to find and use the implementation on the parser class.
+    """
+
+    GETTERCRE = re.compile(r"^get(?P<name>.+)$")
+
+    def __init__(self, parser):
+        self._parser = parser
+        self._data = {}
+        for getter in dir(self._parser):
+            m = self.GETTERCRE.match(getter)
+            if not m or not callable(getattr(self._parser, getter)):
+                continue
+            self._data[m.group('name')] = None   # See class docstring.
+
+    def __getitem__(self, key):
+        return self._data[key]
+
+    def __setitem__(self, key, value):
+        try:
+            k = 'get' + key
+        except TypeError:
+            raise ValueError('Incompatible key: {} (type: {})'
+                             ''.format(key, type(key)))
+        if k == 'get':
+            raise ValueError('Incompatible key: cannot use "" as a name')
+        self._data[key] = value
+        func = functools.partial(self._parser._get_conv, conv=value)
+        func.converter = value
+        setattr(self._parser, k, func)
+        for proxy in self._parser.values():
+            getter = functools.partial(proxy.get, _impl=func)
+            setattr(proxy, k, getter)
+
+    def __delitem__(self, key):
+        try:
+            k = 'get' + (key or None)
+        except TypeError:
+            raise KeyError(key)
+        del self._data[key]
+        for inst in itertools.chain((self._parser,), self._parser.values()):
+            try:
+                delattr(inst, k)
+            except AttributeError:
+                # don't raise since the entry was present in _data, silently
+                # clean up
+                continue
+
+    def __iter__(self):
+        return iter(self._data)
+
+    def __len__(self):
+        return len(self._data)
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index 82ee955..2fbc90c 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -5,7 +5,7 @@ from collections import deque
 from functools import wraps
 
 __all__ = ["contextmanager", "closing", "ContextDecorator", "ExitStack",
-           "redirect_stdout", "suppress"]
+           "redirect_stdout", "redirect_stderr", "suppress"]
 
 
 class ContextDecorator(object):
@@ -151,8 +151,27 @@ class closing(object):
     def __exit__(self, *exc_info):
         self.thing.close()
 
-class redirect_stdout:
-    """Context manager for temporarily redirecting stdout to another file
+
+class _RedirectStream:
+
+    _stream = None
+
+    def __init__(self, new_target):
+        self._new_target = new_target
+        # We use a list of old targets to make this CM re-entrant
+        self._old_targets = []
+
+    def __enter__(self):
+        self._old_targets.append(getattr(sys, self._stream))
+        setattr(sys, self._stream, self._new_target)
+        return self._new_target
+
+    def __exit__(self, exctype, excinst, exctb):
+        setattr(sys, self._stream, self._old_targets.pop())
+
+
+class redirect_stdout(_RedirectStream):
+    """Context manager for temporarily redirecting stdout to another file.
 
         # How to send help() to stderr
         with redirect_stdout(sys.stderr):
@@ -164,18 +183,13 @@ class redirect_stdout:
                 help(pow)
     """
 
-    def __init__(self, new_target):
-        self._new_target = new_target
-        # We use a list of old targets to make this CM re-entrant
-        self._old_targets = []
+    _stream = "stdout"
 
-    def __enter__(self):
-        self._old_targets.append(sys.stdout)
-        sys.stdout = self._new_target
-        return self._new_target
 
-    def __exit__(self, exctype, excinst, exctb):
-        sys.stdout = self._old_targets.pop()
+class redirect_stderr(_RedirectStream):
+    """Context manager for temporarily redirecting stderr to another file."""
+
+    _stream = "stderr"
 
 
 class suppress:
diff --git a/Lib/copy.py b/Lib/copy.py
index bb8840e..3a45fdf 100644
--- a/Lib/copy.py
+++ b/Lib/copy.py
@@ -94,7 +94,7 @@ def copy(x):
     else:
         reductor = getattr(x, "__reduce_ex__", None)
         if reductor:
-            rv = reductor(2)
+            rv = reductor(4)
         else:
             reductor = getattr(x, "__reduce__", None)
             if reductor:
@@ -171,7 +171,7 @@ def deepcopy(x, memo=None, _nil=[]):
                 else:
                     reductor = getattr(x, "__reduce_ex__", None)
                     if reductor:
-                        rv = reductor(2)
+                        rv = reductor(4)
                     else:
                         reductor = getattr(x, "__reduce__", None)
                         if reductor:
@@ -221,17 +221,15 @@ def _deepcopy_list(x, memo):
 d[list] = _deepcopy_list
 
 def _deepcopy_tuple(x, memo):
-    y = []
-    for a in x:
-        y.append(deepcopy(a, memo))
+    y = [deepcopy(a, memo) for a in x]
     # We're not going to put the tuple in the memo, but it's still important we
     # check for it, in case the tuple contains recursive mutable structures.
     try:
         return memo[id(x)]
     except KeyError:
         pass
-    for i in range(len(x)):
-        if x[i] is not y[i]:
+    for k, j in zip(x, y):
+        if k is not j:
             y = tuple(y)
             break
     else:
diff --git a/Lib/csv.py b/Lib/csv.py
index a56eed8..ca40e5e 100644
--- a/Lib/csv.py
+++ b/Lib/csv.py
@@ -147,16 +147,13 @@ class DictWriter:
             if wrong_fields:
                 raise ValueError("dict contains fields not in fieldnames: "
                                  + ", ".join([repr(x) for x in wrong_fields]))
-        return [rowdict.get(key, self.restval) for key in self.fieldnames]
+        return (rowdict.get(key, self.restval) for key in self.fieldnames)
 
     def writerow(self, rowdict):
         return self.writer.writerow(self._dict_to_list(rowdict))
 
     def writerows(self, rowdicts):
-        rows = []
-        for rowdict in rowdicts:
-            rows.append(self._dict_to_list(rowdict))
-        return self.writer.writerows(rows)
+        return self.writer.writerows(map(self._dict_to_list, rowdicts))
 
 # Guard Sniffer's type checking against builds that exclude complex()
 try:
@@ -231,20 +228,21 @@ class Sniffer:
         quotes = {}
         delims = {}
         spaces = 0
+        groupindex = regexp.groupindex
         for m in matches:
-            n = regexp.groupindex['quote'] - 1
+            n = groupindex['quote'] - 1
             key = m[n]
             if key:
                 quotes[key] = quotes.get(key, 0) + 1
             try:
-                n = regexp.groupindex['delim'] - 1
+                n = groupindex['delim'] - 1
                 key = m[n]
             except KeyError:
                 continue
             if key and (delimiters is None or key in delimiters):
                 delims[key] = delims.get(key, 0) + 1
             try:
-                n = regexp.groupindex['space'] - 1
+                n = groupindex['space'] - 1
             except KeyError:
                 continue
             if m[n]:
diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py
index 5c803ff..4cb6d0d 100644
--- a/Lib/ctypes/__init__.py
+++ b/Lib/ctypes/__init__.py
@@ -237,14 +237,8 @@ _check_size(c_char)
 
 class c_char_p(_SimpleCData):
     _type_ = "z"
-    if _os.name == "nt":
-        def __repr__(self):
-            if not windll.kernel32.IsBadStringPtrA(self, -1):
-                return "%s(%r)" % (self.__class__.__name__, self.value)
-            return "%s(%s)" % (self.__class__.__name__, cast(self, c_void_p).value)
-    else:
-        def __repr__(self):
-            return "%s(%s)" % (self.__class__.__name__, cast(self, c_void_p).value)
+    def __repr__(self):
+        return "%s(%s)" % (self.__class__.__name__, c_void_p.from_buffer(self).value)
 _check_size(c_char_p, "P")
 
 class c_void_p(_SimpleCData):
@@ -259,6 +253,8 @@ from _ctypes import POINTER, pointer, _pointer_type_cache
 
 class c_wchar_p(_SimpleCData):
     _type_ = "Z"
+    def __repr__(self):
+        return "%s(%s)" % (self.__class__.__name__, c_void_p.from_buffer(self).value)
 
 class c_wchar(_SimpleCData):
     _type_ = "u"
@@ -353,7 +349,7 @@ class CDLL(object):
             self._handle = handle
 
     def __repr__(self):
-        return "<%s '%s', handle %x at %x>" % \
+        return "<%s '%s', handle %x at %#x>" % \
                (self.__class__.__name__, self._name,
                 (self._handle & (_sys.maxsize*2 + 1)),
                 id(self) & (_sys.maxsize*2 + 1))
diff --git a/Lib/ctypes/_endian.py b/Lib/ctypes/_endian.py
index dae65fc..37444bd 100644
--- a/Lib/ctypes/_endian.py
+++ b/Lib/ctypes/_endian.py
@@ -45,6 +45,7 @@ if sys.byteorder == "little":
 
     class BigEndianStructure(Structure, metaclass=_swapped_meta):
         """Structure with big endian byte order"""
+        __slots__ = ()
         _swappedbytes_ = None
 
 elif sys.byteorder == "big":
@@ -53,6 +54,7 @@ elif sys.byteorder == "big":
     BigEndianStructure = Structure
     class LittleEndianStructure(Structure, metaclass=_swapped_meta):
         """Structure with little endian byte order"""
+        __slots__ = ()
         _swappedbytes_ = None
 
 else:
diff --git a/Lib/ctypes/test/test_byteswap.py b/Lib/ctypes/test/test_byteswap.py
index 427bb8b..01c97e8 100644
--- a/Lib/ctypes/test/test_byteswap.py
+++ b/Lib/ctypes/test/test_byteswap.py
@@ -22,6 +22,26 @@ class Test(unittest.TestCase):
             setattr(bits, "i%s" % i, 1)
             dump(bits)
 
+    def test_slots(self):
+        class BigPoint(BigEndianStructure):
+            __slots__ = ()
+            _fields_ = [("x", c_int), ("y", c_int)]
+
+        class LowPoint(LittleEndianStructure):
+            __slots__ = ()
+            _fields_ = [("x", c_int), ("y", c_int)]
+
+        big = BigPoint()
+        little = LowPoint()
+        big.x = 4
+        big.y = 2
+        little.x = 2
+        little.y = 4
+        with self.assertRaises(AttributeError):
+            big.z = 42
+        with self.assertRaises(AttributeError):
+            little.z = 24
+
     def test_endian_short(self):
         if sys.byteorder == "little":
             self.assertIs(c_short.__ctype_le__, c_short)
diff --git a/Lib/ctypes/test/test_loading.py b/Lib/ctypes/test/test_loading.py
index 4fb8964..28468c1 100644
--- a/Lib/ctypes/test/test_loading.py
+++ b/Lib/ctypes/test/test_loading.py
@@ -52,7 +52,9 @@ class LoaderTest(unittest.TestCase):
     @unittest.skipUnless(os.name in ("nt", "ce"),
                          'test specific to Windows (NT/CE)')
     def test_load_library(self):
-        self.assertIsNotNone(libc_name)
+        # CRT is no longer directly loadable. See issue23606 for the
+        # discussion about alternative approaches.
+        #self.assertIsNotNone(libc_name)
         if test.support.verbose:
             print(find_library("kernel32"))
             print(find_library("user32"))
diff --git a/Lib/ctypes/test/test_pointers.py b/Lib/ctypes/test/test_pointers.py
index e24a520..40738f7 100644
--- a/Lib/ctypes/test/test_pointers.py
+++ b/Lib/ctypes/test/test_pointers.py
@@ -22,7 +22,10 @@ class PointersTestCase(unittest.TestCase):
     def test_pass_pointers(self):
         dll = CDLL(_ctypes_test.__file__)
         func = dll._testfunc_p_p
-        func.restype = c_long
+        if sizeof(c_longlong) == sizeof(c_void_p):
+            func.restype = c_longlong
+        else:
+            func.restype = c_long
 
         i = c_int(12345678)
 ##        func.argtypes = (POINTER(c_int),)
diff --git a/Lib/ctypes/test/test_prototypes.py b/Lib/ctypes/test/test_prototypes.py
index 818c111..cd0c649 100644
--- a/Lib/ctypes/test/test_prototypes.py
+++ b/Lib/ctypes/test/test_prototypes.py
@@ -69,7 +69,10 @@ class CharPointersTestCase(unittest.TestCase):
 
     def test_int_pointer_arg(self):
         func = testdll._testfunc_p_p
-        func.restype = c_long
+        if sizeof(c_longlong) == sizeof(c_void_p):
+            func.restype = c_longlong
+        else:
+            func.restype = c_long
         self.assertEqual(0, func(0))
 
         ci = c_int(0)
diff --git a/Lib/ctypes/util.py b/Lib/ctypes/util.py
index 595113b..9e74ccd 100644
--- a/Lib/ctypes/util.py
+++ b/Lib/ctypes/util.py
@@ -19,6 +19,8 @@ if os.name == "nt":
         i = i + len(prefix)
         s, rest = sys.version[i:].split(" ", 1)
         majorVersion = int(s[:-2]) - 6
+        if majorVersion >= 13:
+            majorVersion += 1
         minorVersion = int(s[2:3]) / 10.0
         # I don't think paths are affected by minor version in version 6
         if majorVersion == 6:
@@ -36,8 +38,12 @@ if os.name == "nt":
             return None
         if version <= 6:
             clibname = 'msvcrt'
-        else:
+        elif version <= 13:
             clibname = 'msvcr%d' % (version * 10)
+        else:
+            # CRT is no longer directly loadable. See issue23606 for the
+            # discussion about alternative approaches.
+            return None
 
         # If python was built with in debug mode
         import importlib.machinery
diff --git a/Lib/datetime.py b/Lib/datetime.py
index 34e5d38..db13b12 100644
--- a/Lib/datetime.py
+++ b/Lib/datetime.py
@@ -12,7 +12,7 @@ def _cmp(x, y):
 
 MINYEAR = 1
 MAXYEAR = 9999
-_MAXORDINAL = 3652059 # date.max.toordinal()
+_MAXORDINAL = 3652059  # date.max.toordinal()
 
 # Utility functions, adapted from Python's Demo/classes/Dates.py, which
 # also assumes the current Gregorian calendar indefinitely extended in
@@ -26,7 +26,7 @@ _MAXORDINAL = 3652059 # date.max.toordinal()
 # -1 is a placeholder for indexing purposes.
 _DAYS_IN_MONTH = [-1, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
 
-_DAYS_BEFORE_MONTH = [-1] # -1 is a placeholder for indexing purposes.
+_DAYS_BEFORE_MONTH = [-1]  # -1 is a placeholder for indexing purposes.
 dbm = 0
 for dim in _DAYS_IN_MONTH[1:]:
     _DAYS_BEFORE_MONTH.append(dbm)
@@ -162,9 +162,9 @@ def _format_time(hh, mm, ss, us):
 # Correctly substitute for %z and %Z escapes in strftime formats.
 def _wrap_strftime(object, format, timetuple):
     # Don't call utcoffset() or tzname() unless actually needed.
-    freplace = None # the string to use for %f
-    zreplace = None # the string to use for %z
-    Zreplace = None # the string to use for %Z
+    freplace = None  # the string to use for %f
+    zreplace = None  # the string to use for %z
+    Zreplace = None  # the string to use for %Z
 
     # Scan format for %z and %Z escapes, replacing as needed.
     newformat = []
@@ -217,11 +217,6 @@ def _wrap_strftime(object, format, timetuple):
     newformat = "".join(newformat)
     return _time.strftime(newformat, timetuple)
 
-def _call_tzinfo_method(tzinfo, methname, tzinfoarg):
-    if tzinfo is None:
-        return None
-    return getattr(tzinfo, methname)(tzinfoarg)
-
 # Just raise TypeError if the arg isn't None or a string.
 def _check_tzname(name):
     if name is not None and not isinstance(name, str):
@@ -245,13 +240,31 @@ def _check_utc_offset(name, offset):
         raise ValueError("tzinfo.%s() must return a whole number "
                          "of minutes, got %s" % (name, offset))
     if not -timedelta(1) < offset < timedelta(1):
-        raise ValueError("%s()=%s, must be must be strictly between"
-                         " -timedelta(hours=24) and timedelta(hours=24)"
-                         % (name, offset))
+        raise ValueError("%s()=%s, must be must be strictly between "
+                         "-timedelta(hours=24) and timedelta(hours=24)" %
+                         (name, offset))
+
+def _check_int_field(value):
+    if isinstance(value, int):
+        return value
+    if not isinstance(value, float):
+        try:
+            value = value.__int__()
+        except AttributeError:
+            pass
+        else:
+            if isinstance(value, int):
+                return value
+            raise TypeError('__int__ returned non-int (type %s)' %
+                            type(value).__name__)
+        raise TypeError('an integer is required (got type %s)' %
+                        type(value).__name__)
+    raise TypeError('integer argument expected, got float')
 
 def _check_date_fields(year, month, day):
-    if not isinstance(year, int):
-        raise TypeError('int expected')
+    year = _check_int_field(year)
+    month = _check_int_field(month)
+    day = _check_int_field(day)
     if not MINYEAR <= year <= MAXYEAR:
         raise ValueError('year must be in %d..%d' % (MINYEAR, MAXYEAR), year)
     if not 1 <= month <= 12:
@@ -259,10 +272,13 @@ def _check_date_fields(year, month, day):
     dim = _days_in_month(year, month)
     if not 1 <= day <= dim:
         raise ValueError('day must be in 1..%d' % dim, day)
+    return year, month, day
 
 def _check_time_fields(hour, minute, second, microsecond):
-    if not isinstance(hour, int):
-        raise TypeError('int expected')
+    hour = _check_int_field(hour)
+    minute = _check_int_field(minute)
+    second = _check_int_field(second)
+    microsecond = _check_int_field(microsecond)
     if not 0 <= hour <= 23:
         raise ValueError('hour must be in 0..23', hour)
     if not 0 <= minute <= 59:
@@ -271,6 +287,7 @@ def _check_time_fields(hour, minute, second, microsecond):
         raise ValueError('second must be in 0..59', second)
     if not 0 <= microsecond <= 999999:
         raise ValueError('microsecond must be in 0..999999', microsecond)
+    return hour, minute, second, microsecond
 
 def _check_tzinfo_arg(tz):
     if tz is not None and not isinstance(tz, tzinfo):
@@ -316,7 +333,7 @@ class timedelta:
     Representation: (days, seconds, microseconds).  Why?  Because I
     felt like it.
     """
-    __slots__ = '_days', '_seconds', '_microseconds'
+    __slots__ = '_days', '_seconds', '_microseconds', '_hashcode'
 
     def __new__(cls, days=0, seconds=0, microseconds=0,
                 milliseconds=0, minutes=0, hours=0, weeks=0):
@@ -382,38 +399,26 @@ class timedelta:
         # secondsfrac isn't referenced again
 
         if isinstance(microseconds, float):
-            microseconds += usdouble
-            microseconds = round(microseconds, 0)
-            seconds, microseconds = divmod(microseconds, 1e6)
-            assert microseconds == int(microseconds)
-            assert seconds == int(seconds)
-            days, seconds = divmod(seconds, 24.*3600.)
-            assert days == int(days)
-            assert seconds == int(seconds)
-            d += int(days)
-            s += int(seconds)   # can't overflow
-            assert isinstance(s, int)
-            assert abs(s) <= 3 * 24 * 3600
+            microseconds = round(microseconds + usdouble)
+            seconds, microseconds = divmod(microseconds, 1000000)
+            days, seconds = divmod(seconds, 24*3600)
+            d += days
+            s += seconds
         else:
+            microseconds = int(microseconds)
             seconds, microseconds = divmod(microseconds, 1000000)
             days, seconds = divmod(seconds, 24*3600)
             d += days
-            s += int(seconds)    # can't overflow
-            assert isinstance(s, int)
-            assert abs(s) <= 3 * 24 * 3600
-            microseconds = float(microseconds)
-            microseconds += usdouble
-            microseconds = round(microseconds, 0)
+            s += seconds
+            microseconds = round(microseconds + usdouble)
+        assert isinstance(s, int)
+        assert isinstance(microseconds, int)
         assert abs(s) <= 3 * 24 * 3600
         assert abs(microseconds) < 3.1e6
 
         # Just a little bit of carrying possible for microseconds and seconds.
-        assert isinstance(microseconds, float)
-        assert int(microseconds) == microseconds
-        us = int(microseconds)
-        seconds, us = divmod(us, 1000000)
-        s += seconds    # cant't overflow
-        assert isinstance(s, int)
+        seconds, us = divmod(microseconds, 1000000)
+        s += seconds
         days, s = divmod(s, 24*3600)
         d += days
 
@@ -421,27 +426,31 @@ class timedelta:
         assert isinstance(s, int) and 0 <= s < 24*3600
         assert isinstance(us, int) and 0 <= us < 1000000
 
-        self = object.__new__(cls)
+        if abs(d) > 999999999:
+            raise OverflowError("timedelta # of days is too large: %d" % d)
 
+        self = object.__new__(cls)
         self._days = d
         self._seconds = s
         self._microseconds = us
-        if abs(d) > 999999999:
-            raise OverflowError("timedelta # of days is too large: %d" % d)
-
+        self._hashcode = -1
         return self
 
     def __repr__(self):
         if self._microseconds:
-            return "%s(%d, %d, %d)" % ('datetime.' + self.__class__.__name__,
-                                       self._days,
-                                       self._seconds,
-                                       self._microseconds)
+            return "%s.%s(%d, %d, %d)" % (self.__class__.__module__,
+                                          self.__class__.__qualname__,
+                                          self._days,
+                                          self._seconds,
+                                          self._microseconds)
         if self._seconds:
-            return "%s(%d, %d)" % ('datetime.' + self.__class__.__name__,
-                                   self._days,
-                                   self._seconds)
-        return "%s(%d)" % ('datetime.' + self.__class__.__name__, self._days)
+            return "%s.%s(%d, %d)" % (self.__class__.__module__,
+                                      self.__class__.__qualname__,
+                                      self._days,
+                                      self._seconds)
+        return "%s.%s(%d)" % (self.__class__.__module__,
+                              self.__class__.__qualname__,
+                              self._days)
 
     def __str__(self):
         mm, ss = divmod(self._seconds, 60)
@@ -457,7 +466,7 @@ class timedelta:
 
     def total_seconds(self):
         """Total seconds in the duration."""
-        return ((self.days * 86400 + self.seconds)*10**6 +
+        return ((self.days * 86400 + self.seconds) * 10**6 +
                 self.microseconds) / 10**6
 
     # Read-only field accessors
@@ -578,12 +587,6 @@ class timedelta:
         else:
             return False
 
-    def __ne__(self, other):
-        if isinstance(other, timedelta):
-            return self._cmp(other) != 0
-        else:
-            return True
-
     def __le__(self, other):
         if isinstance(other, timedelta):
             return self._cmp(other) <= 0
@@ -613,7 +616,9 @@ class timedelta:
         return _cmp(self._getstate(), other._getstate())
 
     def __hash__(self):
-        return hash(self._getstate())
+        if self._hashcode == -1:
+            self._hashcode = hash(self._getstate())
+        return self._hashcode
 
     def __bool__(self):
         return (self._days != 0 or
@@ -661,7 +666,7 @@ class date:
     Properties (readonly):
     year, month, day
     """
-    __slots__ = '_year', '_month', '_day'
+    __slots__ = '_year', '_month', '_day', '_hashcode'
 
     def __new__(cls, year, month=None, day=None):
         """Constructor.
@@ -670,17 +675,19 @@ class date:
 
         year, month, day (required, base 1)
         """
-        if (isinstance(year, bytes) and len(year) == 4 and
-            1 <= year[2] <= 12 and month is None):  # Month is sane
+        if month is None and isinstance(year, bytes) and len(year) == 4 and \
+                1 <= year[2] <= 12:
             # Pickle support
             self = object.__new__(cls)
             self.__setstate(year)
+            self._hashcode = -1
             return self
-        _check_date_fields(year, month, day)
+        year, month, day = _check_date_fields(year, month, day)
         self = object.__new__(cls)
         self._year = year
         self._month = month
         self._day = day
+        self._hashcode = -1
         return self
 
     # Additional constructors
@@ -720,10 +727,11 @@ class date:
         >>> repr(dt)
         'datetime.datetime(2010, 1, 1, 0, 0, tzinfo=datetime.timezone.utc)'
         """
-        return "%s(%d, %d, %d)" % ('datetime.' + self.__class__.__name__,
-                                   self._year,
-                                   self._month,
-                                   self._day)
+        return "%s.%s(%d, %d, %d)" % (self.__class__.__module__,
+                                      self.__class__.__qualname__,
+                                      self._year,
+                                      self._month,
+                                      self._day)
     # XXX These shouldn't depend on time.localtime(), because that
     # clips the usable dates to [1970 .. 2038).  At least ctime() is
     # easily done without using strftime() -- that's better too because
@@ -743,6 +751,8 @@ class date:
         return _wrap_strftime(self, fmt, self.timetuple())
 
     def __format__(self, fmt):
+        if not isinstance(fmt, str):
+            raise TypeError("must be str, not %s" % type(fmt).__name__)
         if len(fmt) != 0:
             return self.strftime(fmt)
         return str(self)
@@ -800,7 +810,6 @@ class date:
             month = self._month
         if day is None:
             day = self._day
-        _check_date_fields(year, month, day)
         return date(year, month, day)
 
     # Comparisons of date objects with other.
@@ -810,11 +819,6 @@ class date:
             return self._cmp(other) == 0
         return NotImplemented
 
-    def __ne__(self, other):
-        if isinstance(other, date):
-            return self._cmp(other) != 0
-        return NotImplemented
-
     def __le__(self, other):
         if isinstance(other, date):
             return self._cmp(other) <= 0
@@ -843,7 +847,9 @@ class date:
 
     def __hash__(self):
         "Hash."
-        return hash(self._getstate())
+        if self._hashcode == -1:
+            self._hashcode = hash(self._getstate())
+        return self._hashcode
 
     # Computations
 
@@ -913,8 +919,6 @@ class date:
         return bytes([yhi, ylo, self._month, self._day]),
 
     def __setstate(self, string):
-        if len(string) != 4 or not (1 <= string[2] <= 12):
-            raise TypeError("not enough arguments")
         yhi, ylo, self._month, self._day = string
         self._year = yhi * 256 + ylo
 
@@ -933,6 +937,7 @@ class tzinfo:
     Subclasses must override the name(), utcoffset() and dst() methods.
     """
     __slots__ = ()
+
     def tzname(self, dt):
         "datetime -> string name of time zone."
         raise NotImplementedError("tzinfo subclass must override tzname()")
@@ -1019,6 +1024,7 @@ class time:
     Properties (readonly):
     hour, minute, second, microsecond, tzinfo
     """
+    __slots__ = '_hour', '_minute', '_second', '_microsecond', '_tzinfo', '_hashcode'
 
     def __new__(cls, hour=0, minute=0, second=0, microsecond=0, tzinfo=None):
         """Constructor.
@@ -1029,18 +1035,22 @@ class time:
         second, microsecond (default to zero)
         tzinfo (default to None)
         """
-        self = object.__new__(cls)
-        if isinstance(hour, bytes) and len(hour) == 6:
+        if isinstance(hour, bytes) and len(hour) == 6 and hour[0] < 24:
             # Pickle support
+            self = object.__new__(cls)
             self.__setstate(hour, minute or None)
+            self._hashcode = -1
             return self
+        hour, minute, second, microsecond = _check_time_fields(
+            hour, minute, second, microsecond)
         _check_tzinfo_arg(tzinfo)
-        _check_time_fields(hour, minute, second, microsecond)
+        self = object.__new__(cls)
         self._hour = hour
         self._minute = minute
         self._second = second
         self._microsecond = microsecond
         self._tzinfo = tzinfo
+        self._hashcode = -1
         return self
 
     # Read-only field accessors
@@ -1079,12 +1089,6 @@ class time:
         else:
             return False
 
-    def __ne__(self, other):
-        if isinstance(other, time):
-            return self._cmp(other, allow_mixed=True) != 0
-        else:
-            return True
-
     def __le__(self, other):
         if isinstance(other, time):
             return self._cmp(other) <= 0
@@ -1125,8 +1129,8 @@ class time:
         if base_compare:
             return _cmp((self._hour, self._minute, self._second,
                          self._microsecond),
-                       (other._hour, other._minute, other._second,
-                        other._microsecond))
+                        (other._hour, other._minute, other._second,
+                         other._microsecond))
         if myoff is None or otoff is None:
             if allow_mixed:
                 return 2 # arbitrary non-zero value
@@ -1139,16 +1143,20 @@ class time:
 
     def __hash__(self):
         """Hash."""
-        tzoff = self.utcoffset()
-        if not tzoff: # zero or None
-            return hash(self._getstate()[0])
-        h, m = divmod(timedelta(hours=self.hour, minutes=self.minute) - tzoff,
-                      timedelta(hours=1))
-        assert not m % timedelta(minutes=1), "whole minute"
-        m //= timedelta(minutes=1)
-        if 0 <= h < 24:
-            return hash(time(h, m, self.second, self.microsecond))
-        return hash((h, m, self.second, self.microsecond))
+        if self._hashcode == -1:
+            tzoff = self.utcoffset()
+            if not tzoff:  # zero or None
+                self._hashcode = hash(self._getstate()[0])
+            else:
+                h, m = divmod(timedelta(hours=self.hour, minutes=self.minute) - tzoff,
+                              timedelta(hours=1))
+                assert not m % timedelta(minutes=1), "whole minute"
+                m //= timedelta(minutes=1)
+                if 0 <= h < 24:
+                    self._hashcode = hash(time(h, m, self.second, self.microsecond))
+                else:
+                    self._hashcode = hash((h, m, self.second, self.microsecond))
+        return self._hashcode
 
     # Conversion to string
 
@@ -1176,8 +1184,9 @@ class time:
             s = ", %d" % self._second
         else:
             s = ""
-        s= "%s(%d, %d%s)" % ('datetime.' + self.__class__.__name__,
-                             self._hour, self._minute, s)
+        s= "%s.%s(%d, %d%s)" % (self.__class__.__module__,
+                                self.__class__.__qualname__,
+                                self._hour, self._minute, s)
         if self._tzinfo is not None:
             assert s[-1:] == ")"
             s = s[:-1] + ", tzinfo=%r" % self._tzinfo + ")"
@@ -1210,6 +1219,8 @@ class time:
         return _wrap_strftime(self, fmt, timetuple)
 
     def __format__(self, fmt):
+        if not isinstance(fmt, str):
+            raise TypeError("must be str, not %s" % type(fmt).__name__)
         if len(fmt) != 0:
             return self.strftime(fmt)
         return str(self)
@@ -1266,16 +1277,8 @@ class time:
             microsecond = self.microsecond
         if tzinfo is True:
             tzinfo = self.tzinfo
-        _check_time_fields(hour, minute, second, microsecond)
-        _check_tzinfo_arg(tzinfo)
         return time(hour, minute, second, microsecond, tzinfo)
 
-    def __bool__(self):
-        if self.second or self.microsecond:
-            return True
-        offset = self.utcoffset() or timedelta(0)
-        return timedelta(hours=self.hour, minutes=self.minute) != offset
-
     # Pickle support.
 
     def _getstate(self):
@@ -1289,15 +1292,11 @@ class time:
             return (basestate, self._tzinfo)
 
     def __setstate(self, string, tzinfo):
-        if len(string) != 6 or string[0] >= 24:
-            raise TypeError("an integer is required")
-        (self._hour, self._minute, self._second,
-         us1, us2, us3) = string
+        if tzinfo is not None and not isinstance(tzinfo, _tzinfo_class):
+            raise TypeError("bad tzinfo state arg")
+        self._hour, self._minute, self._second, us1, us2, us3 = string
         self._microsecond = (((us1 << 8) | us2) << 8) | us3
-        if tzinfo is None or isinstance(tzinfo, _tzinfo_class):
-            self._tzinfo = tzinfo
-        else:
-            raise TypeError("bad tzinfo state arg %r" % tzinfo)
+        self._tzinfo = tzinfo
 
     def __reduce__(self):
         return (time, self._getstate())
@@ -1314,25 +1313,30 @@ class datetime(date):
     The year, month and day arguments are required. tzinfo may be None, or an
     instance of a tzinfo subclass. The remaining arguments may be ints.
     """
+    __slots__ = date.__slots__ + time.__slots__
 
-    __slots__ = date.__slots__ + (
-        '_hour', '_minute', '_second',
-        '_microsecond', '_tzinfo')
     def __new__(cls, year, month=None, day=None, hour=0, minute=0, second=0,
                 microsecond=0, tzinfo=None):
-        if isinstance(year, bytes) and len(year) == 10:
+        if isinstance(year, bytes) and len(year) == 10 and 1 <= year[2] <= 12:
             # Pickle support
-            self = date.__new__(cls, year[:4])
+            self = object.__new__(cls)
             self.__setstate(year, month)
+            self._hashcode = -1
             return self
+        year, month, day = _check_date_fields(year, month, day)
+        hour, minute, second, microsecond = _check_time_fields(
+            hour, minute, second, microsecond)
         _check_tzinfo_arg(tzinfo)
-        _check_time_fields(hour, minute, second, microsecond)
-        self = date.__new__(cls, year, month, day)
+        self = object.__new__(cls)
+        self._year = year
+        self._month = month
+        self._day = day
         self._hour = hour
         self._minute = minute
         self._second = second
         self._microsecond = microsecond
         self._tzinfo = tzinfo
+        self._hashcode = -1
         return self
 
     # Read-only field accessors
@@ -1367,7 +1371,6 @@ class datetime(date):
 
         A timezone info object may be passed in as well.
         """
-
         _check_tzinfo_arg(tz)
 
         converter = _time.localtime if tz is None else _time.gmtime
@@ -1391,7 +1394,7 @@ class datetime(date):
 
     @classmethod
     def utcfromtimestamp(cls, t):
-        "Construct a UTC datetime from a POSIX timestamp (like time.time())."
+        """Construct a naive UTC datetime from a POSIX timestamp."""
         t, frac = divmod(t, 1.0)
         us = int(frac * 1e6)
 
@@ -1406,11 +1409,6 @@ class datetime(date):
         ss = min(ss, 59)    # clamp out leap seconds if the platform has them
         return cls(y, m, d, hh, mm, ss, us)
 
-    # XXX This is supposed to do better than we *can* do by using time.time(),
-    # XXX if the platform supports a more accurate way.  The C implementation
-    # XXX uses gettimeofday on platforms that have it, but that isn't
-    # XXX available from Python.  So now() may return different results
-    # XXX across the implementations.
     @classmethod
     def now(cls, tz=None):
         "Construct a datetime from time.time() and optional time zone info."
@@ -1497,11 +1495,8 @@ class datetime(date):
             microsecond = self.microsecond
         if tzinfo is True:
             tzinfo = self.tzinfo
-        _check_date_fields(year, month, day)
-        _check_time_fields(hour, minute, second, microsecond)
-        _check_tzinfo_arg(tzinfo)
-        return datetime(year, month, day, hour, minute, second,
-                          microsecond, tzinfo)
+        return datetime(year, month, day, hour, minute, second, microsecond,
+                        tzinfo)
 
     def astimezone(self, tz=None):
         if tz is None:
@@ -1571,10 +1566,9 @@ class datetime(date):
         Optional argument sep specifies the separator between date and
         time, default 'T'.
         """
-        s = ("%04d-%02d-%02d%c" % (self._year, self._month, self._day,
-                                  sep) +
-                _format_time(self._hour, self._minute, self._second,
-                             self._microsecond))
+        s = ("%04d-%02d-%02d%c" % (self._year, self._month, self._day, sep) +
+             _format_time(self._hour, self._minute, self._second,
+                          self._microsecond))
         off = self.utcoffset()
         if off is not None:
             if off.days < 0:
@@ -1590,14 +1584,15 @@ class datetime(date):
 
     def __repr__(self):
         """Convert to formal string, for repr()."""
-        L = [self._year, self._month, self._day, # These are never zero
+        L = [self._year, self._month, self._day,  # These are never zero
              self._hour, self._minute, self._second, self._microsecond]
         if L[-1] == 0:
             del L[-1]
         if L[-1] == 0:
             del L[-1]
-        s = ", ".join(map(str, L))
-        s = "%s(%s)" % ('datetime.' + self.__class__.__name__, s)
+        s = "%s.%s(%s)" % (self.__class__.__module__,
+                           self.__class__.__qualname__,
+                           ", ".join(map(str, L)))
         if self._tzinfo is not None:
             assert s[-1:] == ")"
             s = s[:-1] + ", tzinfo=%r" % self._tzinfo + ")"
@@ -1629,7 +1624,9 @@ class datetime(date):
         it mean anything in particular. For example, "GMT", "UTC", "-500",
         "-5:00", "EDT", "US/Eastern", "America/New York" are all valid replies.
         """
-        name = _call_tzinfo_method(self._tzinfo, "tzname", self)
+        if self._tzinfo is None:
+            return None
+        name = self._tzinfo.tzname(self)
         _check_tzname(name)
         return name
 
@@ -1658,14 +1655,6 @@ class datetime(date):
         else:
             return False
 
-    def __ne__(self, other):
-        if isinstance(other, datetime):
-            return self._cmp(other, allow_mixed=True) != 0
-        elif not isinstance(other, date):
-            return NotImplemented
-        else:
-            return True
-
     def __le__(self, other):
         if isinstance(other, datetime):
             return self._cmp(other) <= 0
@@ -1715,9 +1704,9 @@ class datetime(date):
             return _cmp((self._year, self._month, self._day,
                          self._hour, self._minute, self._second,
                          self._microsecond),
-                       (other._year, other._month, other._day,
-                        other._hour, other._minute, other._second,
-                        other._microsecond))
+                        (other._year, other._month, other._day,
+                         other._hour, other._minute, other._second,
+                         other._microsecond))
         if myoff is None or otoff is None:
             if allow_mixed:
                 return 2 # arbitrary non-zero value
@@ -1775,12 +1764,15 @@ class datetime(date):
         return base + otoff - myoff
 
     def __hash__(self):
-        tzoff = self.utcoffset()
-        if tzoff is None:
-            return hash(self._getstate()[0])
-        days = _ymd2ord(self.year, self.month, self.day)
-        seconds = self.hour * 3600 + self.minute * 60 + self.second
-        return hash(timedelta(days, seconds, self.microsecond) - tzoff)
+        if self._hashcode == -1:
+            tzoff = self.utcoffset()
+            if tzoff is None:
+                self._hashcode = hash(self._getstate()[0])
+            else:
+                days = _ymd2ord(self.year, self.month, self.day)
+                seconds = self.hour * 3600 + self.minute * 60 + self.second
+                self._hashcode = hash(timedelta(days, seconds, self.microsecond) - tzoff)
+        return self._hashcode
 
     # Pickle support.
 
@@ -1797,14 +1789,13 @@ class datetime(date):
             return (basestate, self._tzinfo)
 
     def __setstate(self, string, tzinfo):
+        if tzinfo is not None and not isinstance(tzinfo, _tzinfo_class):
+            raise TypeError("bad tzinfo state arg")
         (yhi, ylo, self._month, self._day, self._hour,
          self._minute, self._second, us1, us2, us3) = string
         self._year = yhi * 256 + ylo
         self._microsecond = (((us1 << 8) | us2) << 8) | us3
-        if tzinfo is None or isinstance(tzinfo, _tzinfo_class):
-            self._tzinfo = tzinfo
-        else:
-            raise TypeError("bad tzinfo state arg %r" % tzinfo)
+        self._tzinfo = tzinfo
 
     def __reduce__(self):
         return (self.__class__, self._getstate())
@@ -1820,7 +1811,7 @@ def _isoweek1monday(year):
     # XXX This could be done more efficiently
     THURSDAY = 3
     firstday = _ymd2ord(year, 1, 1)
-    firstweekday = (firstday + 6) % 7 # See weekday() above
+    firstweekday = (firstday + 6) % 7  # See weekday() above
     week1monday = firstday - firstweekday
     if firstweekday > THURSDAY:
         week1monday += 7
@@ -1841,13 +1832,12 @@ class timezone(tzinfo):
         elif not isinstance(name, str):
             raise TypeError("name must be a string")
         if not cls._minoffset <= offset <= cls._maxoffset:
-            raise ValueError("offset must be a timedelta"
-                             " strictly between -timedelta(hours=24) and"
-                             " timedelta(hours=24).")
-        if (offset.microseconds != 0 or
-            offset.seconds % 60 != 0):
-            raise ValueError("offset must be a timedelta"
-                             " representing a whole number of minutes")
+            raise ValueError("offset must be a timedelta "
+                             "strictly between -timedelta(hours=24) and "
+                             "timedelta(hours=24).")
+        if (offset.microseconds != 0 or offset.seconds % 60 != 0):
+            raise ValueError("offset must be a timedelta "
+                             "representing a whole number of minutes")
         return cls._create(offset, name)
 
     @classmethod
@@ -1884,10 +1874,12 @@ class timezone(tzinfo):
         if self is self.utc:
             return 'datetime.timezone.utc'
         if self._name is None:
-            return "%s(%r)" % ('datetime.' + self.__class__.__name__,
-                               self._offset)
-        return "%s(%r, %r)" % ('datetime.' + self.__class__.__name__,
-                               self._offset, self._name)
+            return "%s.%s(%r)" % (self.__class__.__module__,
+                                  self.__class__.__qualname__,
+                                  self._offset)
+        return "%s.%s(%r, %r)" % (self.__class__.__module__,
+                                  self.__class__.__qualname__,
+                                  self._offset, self._name)
 
     def __str__(self):
         return self.tzname(None)
@@ -2142,14 +2134,13 @@ except ImportError:
     pass
 else:
     # Clean up unused names
-    del (_DAYNAMES, _DAYS_BEFORE_MONTH, _DAYS_IN_MONTH,
-         _DI100Y, _DI400Y, _DI4Y, _MAXORDINAL, _MONTHNAMES,
-         _build_struct_time, _call_tzinfo_method, _check_date_fields,
-         _check_time_fields, _check_tzinfo_arg, _check_tzname,
-         _check_utc_offset, _cmp, _cmperror, _date_class, _days_before_month,
-         _days_before_year, _days_in_month, _format_time, _is_leap,
-         _isoweek1monday, _math, _ord2ymd, _time, _time_class, _tzinfo_class,
-         _wrap_strftime, _ymd2ord)
+    del (_DAYNAMES, _DAYS_BEFORE_MONTH, _DAYS_IN_MONTH, _DI100Y, _DI400Y,
+         _DI4Y, _EPOCH, _MAXORDINAL, _MONTHNAMES, _build_struct_time,
+         _check_date_fields, _check_int_field, _check_time_fields,
+         _check_tzinfo_arg, _check_tzname, _check_utc_offset, _cmp, _cmperror,
+         _date_class, _days_before_month, _days_before_year, _days_in_month,
+         _format_time, _is_leap, _isoweek1monday, _math, _ord2ymd,
+         _time, _time_class, _tzinfo_class, _wrap_strftime, _ymd2ord)
     # XXX Since import * above excludes names that start with _,
     # docstring does not get overwritten. In the future, it may be
     # appropriate to maintain a single module level docstring and
diff --git a/Lib/dbm/__init__.py b/Lib/dbm/__init__.py
index 5f4664a..6831a84 100644
--- a/Lib/dbm/__init__.py
+++ b/Lib/dbm/__init__.py
@@ -153,9 +153,9 @@ def whichdb(filename):
     except OSError:
         return None
 
-    # Read the start of the file -- the magic number
-    s16 = f.read(16)
-    f.close()
+    with f:
+        # Read the start of the file -- the magic number
+        s16 = f.read(16)
     s = s16[0:4]
 
     # Return "" if not at least 4 bytes
diff --git a/Lib/dbm/dumb.py b/Lib/dbm/dumb.py
index 63bc329..7777a7c 100644
--- a/Lib/dbm/dumb.py
+++ b/Lib/dbm/dumb.py
@@ -45,7 +45,7 @@ class _Database(collections.MutableMapping):
     _os = _os       # for _commit()
     _io = _io       # for _commit()
 
-    def __init__(self, filebasename, mode):
+    def __init__(self, filebasename, mode, flag='c'):
         self._mode = mode
 
         # The directory file is a text file.  Each line looks like
@@ -65,6 +65,17 @@ class _Database(collections.MutableMapping):
         # The index is an in-memory dict, mirroring the directory file.
         self._index = None  # maps keys to (pos, siz) pairs
 
+        # Handle the creation
+        self._create(flag)
+        self._update()
+
+    def _create(self, flag):
+        if flag == 'n':
+            for filename in (self._datfile, self._bakfile, self._dirfile):
+                try:
+                    _os.remove(filename)
+                except OSError:
+                    pass
         # Mod by Jack: create data file if needed
         try:
             f = _io.open(self._datfile, 'r', encoding="Latin-1")
@@ -73,7 +84,6 @@ class _Database(collections.MutableMapping):
                 self._chmod(self._datfile)
         else:
             f.close()
-        self._update()
 
     # Read directory file into the in-memory index dict.
     def _update(self):
@@ -266,20 +276,20 @@ class _Database(collections.MutableMapping):
         self.close()
 
 
-def open(file, flag=None, mode=0o666):
+def open(file, flag='c', mode=0o666):
     """Open the database file, filename, and return corresponding object.
 
     The flag argument, used to control how the database is opened in the
-    other DBM implementations, is ignored in the dbm.dumb module; the
-    database is always opened for update, and will be created if it does
-    not exist.
+    other DBM implementations, supports only the semantics of 'c' and 'n'
+    values.  Other values will default to the semantics of 'c' value:
+    the database will 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 code 0o666 (and
     will be modified by the prevailing umask).
 
     """
-    # flag argument is currently ignored
 
     # Modify mode depending on the umask
     try:
@@ -290,5 +300,4 @@ def open(file, flag=None, mode=0o666):
     else:
         # Turn off any bits that are set in the umask
         mode = mode & (~um)
-
-    return _Database(file, mode)
+    return _Database(file, mode, flag=flag)
diff --git a/Lib/decimal.py b/Lib/decimal.py
index 324e4f9..7746ea2 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -1,6413 +1,11 @@
-# Copyright (c) 2004 Python Software Foundation.
-# All rights reserved.
-
-# Written by Eric Price <eprice at tjhsst.edu>
-#    and Facundo Batista <facundo at taniquetil.com.ar>
-#    and Raymond Hettinger <python at rcn.com>
-#    and Aahz <aahz at pobox.com>
-#    and Tim Peters
-
-# This module should be kept in sync with the latest updates of the
-# IBM specification as it evolves.  Those updates will be treated
-# as bug fixes (deviation from the spec is a compatibility, usability
-# bug) and will be backported.  At this point the spec is stabilizing
-# and the updates are becoming fewer, smaller, and less significant.
-
-"""
-This is an implementation of decimal floating point arithmetic based on
-the General Decimal Arithmetic Specification:
-
-    http://speleotrove.com/decimal/decarith.html
-
-and IEEE standard 854-1987:
-
-    http://en.wikipedia.org/wiki/IEEE_854-1987
-
-Decimal floating point has finite precision with arbitrarily large bounds.
-
-The purpose of this module is to support arithmetic using familiar
-"schoolhouse" rules and to avoid some of the tricky representation
-issues associated with binary floating point.  The package is especially
-useful for financial applications or for contexts where users have
-expectations that are at odds with binary floating point (for instance,
-in binary floating point, 1.00 % 0.1 gives 0.09999999999999995 instead
-of 0.0; Decimal('1.00') % Decimal('0.1') returns the expected
-Decimal('0.00')).
-
-Here are some examples of using the decimal module:
-
->>> from decimal import *
->>> setcontext(ExtendedContext)
->>> Decimal(0)
-Decimal('0')
->>> Decimal('1')
-Decimal('1')
->>> Decimal('-.0123')
-Decimal('-0.0123')
->>> Decimal(123456)
-Decimal('123456')
->>> Decimal('123.45e12345678')
-Decimal('1.2345E+12345680')
->>> Decimal('1.33') + Decimal('1.27')
-Decimal('2.60')
->>> Decimal('12.34') + Decimal('3.87') - Decimal('18.41')
-Decimal('-2.20')
->>> dig = Decimal(1)
->>> print(dig / Decimal(3))
-0.333333333
->>> getcontext().prec = 18
->>> print(dig / Decimal(3))
-0.333333333333333333
->>> print(dig.sqrt())
-1
->>> print(Decimal(3).sqrt())
-1.73205080756887729
->>> print(Decimal(3) ** 123)
-4.85192780976896427E+58
->>> inf = Decimal(1) / Decimal(0)
->>> print(inf)
-Infinity
->>> neginf = Decimal(-1) / Decimal(0)
->>> print(neginf)
--Infinity
->>> print(neginf + inf)
-NaN
->>> print(neginf * inf)
--Infinity
->>> print(dig / 0)
-Infinity
->>> getcontext().traps[DivisionByZero] = 1
->>> print(dig / 0)
-Traceback (most recent call last):
-  ...
-  ...
-  ...
-decimal.DivisionByZero: x / 0
->>> c = Context()
->>> c.traps[InvalidOperation] = 0
->>> print(c.flags[InvalidOperation])
-0
->>> c.divide(Decimal(0), Decimal(0))
-Decimal('NaN')
->>> c.traps[InvalidOperation] = 1
->>> print(c.flags[InvalidOperation])
-1
->>> c.flags[InvalidOperation] = 0
->>> print(c.flags[InvalidOperation])
-0
->>> print(c.divide(Decimal(0), Decimal(0)))
-Traceback (most recent call last):
-  ...
-  ...
-  ...
-decimal.InvalidOperation: 0 / 0
->>> print(c.flags[InvalidOperation])
-1
->>> c.flags[InvalidOperation] = 0
->>> c.traps[InvalidOperation] = 0
->>> print(c.divide(Decimal(0), Decimal(0)))
-NaN
->>> print(c.flags[InvalidOperation])
-1
->>>
-"""
-
-__all__ = [
-    # Two major classes
-    'Decimal', 'Context',
-
-    # Named tuple representation
-    'DecimalTuple',
-
-    # Contexts
-    'DefaultContext', 'BasicContext', 'ExtendedContext',
-
-    # Exceptions
-    'DecimalException', 'Clamped', 'InvalidOperation', 'DivisionByZero',
-    'Inexact', 'Rounded', 'Subnormal', 'Overflow', 'Underflow',
-    'FloatOperation',
-
-    # Exceptional conditions that trigger InvalidOperation
-    'DivisionImpossible', 'InvalidContext', 'ConversionSyntax', 'DivisionUndefined',
-
-    # Constants for use in setting up contexts
-    'ROUND_DOWN', 'ROUND_HALF_UP', 'ROUND_HALF_EVEN', 'ROUND_CEILING',
-    'ROUND_FLOOR', 'ROUND_UP', 'ROUND_HALF_DOWN', 'ROUND_05UP',
-
-    # Functions for manipulating contexts
-    'setcontext', 'getcontext', 'localcontext',
-
-    # Limits for the C version for compatibility
-    'MAX_PREC',  'MAX_EMAX', 'MIN_EMIN', 'MIN_ETINY',
-
-    # C version: compile time choice that enables the thread local context
-    'HAVE_THREADS'
-]
-
-__version__ = '1.70'    # Highest version of the spec this complies with
-                        # See http://speleotrove.com/decimal/
-__libmpdec_version__ = "2.4.1" # compatible libmpdec version
-
-import math as _math
-import numbers as _numbers
-import sys
-
-try:
-    from collections import namedtuple as _namedtuple
-    DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent')
-except ImportError:
-    DecimalTuple = lambda *args: args
-
-# Rounding
-ROUND_DOWN = 'ROUND_DOWN'
-ROUND_HALF_UP = 'ROUND_HALF_UP'
-ROUND_HALF_EVEN = 'ROUND_HALF_EVEN'
-ROUND_CEILING = 'ROUND_CEILING'
-ROUND_FLOOR = 'ROUND_FLOOR'
-ROUND_UP = 'ROUND_UP'
-ROUND_HALF_DOWN = 'ROUND_HALF_DOWN'
-ROUND_05UP = 'ROUND_05UP'
-
-# Compatibility with the C version
-HAVE_THREADS = True
-if sys.maxsize == 2**63-1:
-    MAX_PREC = 999999999999999999
-    MAX_EMAX = 999999999999999999
-    MIN_EMIN = -999999999999999999
-else:
-    MAX_PREC = 425000000
-    MAX_EMAX = 425000000
-    MIN_EMIN = -425000000
-
-MIN_ETINY = MIN_EMIN - (MAX_PREC-1)
-
-# Errors
-
-class DecimalException(ArithmeticError):
-    """Base exception class.
-
-    Used exceptions derive from this.
-    If an exception derives from another exception besides this (such as
-    Underflow (Inexact, Rounded, Subnormal) that indicates that it is only
-    called if the others are present.  This isn't actually used for
-    anything, though.
-
-    handle  -- Called when context._raise_error is called and the
-               trap_enabler is not set.  First argument is self, second is the
-               context.  More arguments can be given, those being after
-               the explanation in _raise_error (For example,
-               context._raise_error(NewError, '(-x)!', self._sign) would
-               call NewError().handle(context, self._sign).)
-
-    To define a new exception, it should be sufficient to have it derive
-    from DecimalException.
-    """
-    def handle(self, context, *args):
-        pass
-
-
-class Clamped(DecimalException):
-    """Exponent of a 0 changed to fit bounds.
-
-    This occurs and signals clamped if the exponent of a result has been
-    altered in order to fit the constraints of a specific concrete
-    representation.  This may occur when the exponent of a zero result would
-    be outside the bounds of a representation, or when a large normal
-    number would have an encoded exponent that cannot be represented.  In
-    this latter case, the exponent is reduced to fit and the corresponding
-    number of zero digits are appended to the coefficient ("fold-down").
-    """
-
-class InvalidOperation(DecimalException):
-    """An invalid operation was performed.
-
-    Various bad things cause this:
-
-    Something creates a signaling NaN
-    -INF + INF
-    0 * (+-)INF
-    (+-)INF / (+-)INF
-    x % 0
-    (+-)INF % x
-    x._rescale( non-integer )
-    sqrt(-x) , x > 0
-    0 ** 0
-    x ** (non-integer)
-    x ** (+-)INF
-    An operand is invalid
-
-    The result of the operation after these is a quiet positive NaN,
-    except when the cause is a signaling NaN, in which case the result is
-    also a quiet NaN, but with the original sign, and an optional
-    diagnostic information.
-    """
-    def handle(self, context, *args):
-        if args:
-            ans = _dec_from_triple(args[0]._sign, args[0]._int, 'n', True)
-            return ans._fix_nan(context)
-        return _NaN
-
-class ConversionSyntax(InvalidOperation):
-    """Trying to convert badly formed string.
-
-    This occurs and signals invalid-operation if an string is being
-    converted to a number and it does not conform to the numeric string
-    syntax.  The result is [0,qNaN].
-    """
-    def handle(self, context, *args):
-        return _NaN
-
-class DivisionByZero(DecimalException, ZeroDivisionError):
-    """Division by 0.
-
-    This occurs and signals division-by-zero if division of a finite number
-    by zero was attempted (during a divide-integer or divide operation, or a
-    power operation with negative right-hand operand), and the dividend was
-    not zero.
-
-    The result of the operation is [sign,inf], where sign is the exclusive
-    or of the signs of the operands for divide, or is 1 for an odd power of
-    -0, for power.
-    """
-
-    def handle(self, context, sign, *args):
-        return _SignedInfinity[sign]
-
-class DivisionImpossible(InvalidOperation):
-    """Cannot perform the division adequately.
-
-    This occurs and signals invalid-operation if the integer result of a
-    divide-integer or remainder operation had too many digits (would be
-    longer than precision).  The result is [0,qNaN].
-    """
-
-    def handle(self, context, *args):
-        return _NaN
-
-class DivisionUndefined(InvalidOperation, ZeroDivisionError):
-    """Undefined result of division.
-
-    This occurs and signals invalid-operation if division by zero was
-    attempted (during a divide-integer, divide, or remainder operation), and
-    the dividend is also zero.  The result is [0,qNaN].
-    """
-
-    def handle(self, context, *args):
-        return _NaN
-
-class Inexact(DecimalException):
-    """Had to round, losing information.
-
-    This occurs and signals inexact whenever the result of an operation is
-    not exact (that is, it needed to be rounded and any discarded digits
-    were non-zero), or if an overflow or underflow condition occurs.  The
-    result in all cases is unchanged.
-
-    The inexact signal may be tested (or trapped) to determine if a given
-    operation (or sequence of operations) was inexact.
-    """
-
-class InvalidContext(InvalidOperation):
-    """Invalid context.  Unknown rounding, for example.
-
-    This occurs and signals invalid-operation if an invalid context was
-    detected during an operation.  This can occur if contexts are not checked
-    on creation and either the precision exceeds the capability of the
-    underlying concrete representation or an unknown or unsupported rounding
-    was specified.  These aspects of the context need only be checked when
-    the values are required to be used.  The result is [0,qNaN].
-    """
-
-    def handle(self, context, *args):
-        return _NaN
-
-class Rounded(DecimalException):
-    """Number got rounded (not  necessarily changed during rounding).
-
-    This occurs and signals rounded whenever the result of an operation is
-    rounded (that is, some zero or non-zero digits were discarded from the
-    coefficient), or if an overflow or underflow condition occurs.  The
-    result in all cases is unchanged.
-
-    The rounded signal may be tested (or trapped) to determine if a given
-    operation (or sequence of operations) caused a loss of precision.
-    """
-
-class Subnormal(DecimalException):
-    """Exponent < Emin before rounding.
-
-    This occurs and signals subnormal whenever the result of a conversion or
-    operation is subnormal (that is, its adjusted exponent is less than
-    Emin, before any rounding).  The result in all cases is unchanged.
-
-    The subnormal signal may be tested (or trapped) to determine if a given
-    or operation (or sequence of operations) yielded a subnormal result.
-    """
-
-class Overflow(Inexact, Rounded):
-    """Numerical overflow.
-
-    This occurs and signals overflow if the adjusted exponent of a result
-    (from a conversion or from an operation that is not an attempt to divide
-    by zero), after rounding, would be greater than the largest value that
-    can be handled by the implementation (the value Emax).
-
-    The result depends on the rounding mode:
-
-    For round-half-up and round-half-even (and for round-half-down and
-    round-up, if implemented), the result of the operation is [sign,inf],
-    where sign is the sign of the intermediate result.  For round-down, the
-    result is the largest finite number that can be represented in the
-    current precision, with the sign of the intermediate result.  For
-    round-ceiling, the result is the same as for round-down if the sign of
-    the intermediate result is 1, or is [0,inf] otherwise.  For round-floor,
-    the result is the same as for round-down if the sign of the intermediate
-    result is 0, or is [1,inf] otherwise.  In all cases, Inexact and Rounded
-    will also be raised.
-    """
-
-    def handle(self, context, sign, *args):
-        if context.rounding in (ROUND_HALF_UP, ROUND_HALF_EVEN,
-                                ROUND_HALF_DOWN, ROUND_UP):
-            return _SignedInfinity[sign]
-        if sign == 0:
-            if context.rounding == ROUND_CEILING:
-                return _SignedInfinity[sign]
-            return _dec_from_triple(sign, '9'*context.prec,
-                            context.Emax-context.prec+1)
-        if sign == 1:
-            if context.rounding == ROUND_FLOOR:
-                return _SignedInfinity[sign]
-            return _dec_from_triple(sign, '9'*context.prec,
-                             context.Emax-context.prec+1)
-
-
-class Underflow(Inexact, Rounded, Subnormal):
-    """Numerical underflow with result rounded to 0.
-
-    This occurs and signals underflow if a result is inexact and the
-    adjusted exponent of the result would be smaller (more negative) than
-    the smallest value that can be handled by the implementation (the value
-    Emin).  That is, the result is both inexact and subnormal.
-
-    The result after an underflow will be a subnormal number rounded, if
-    necessary, so that its exponent is not less than Etiny.  This may result
-    in 0 with the sign of the intermediate result and an exponent of Etiny.
-
-    In all cases, Inexact, Rounded, and Subnormal will also be raised.
-    """
-
-class FloatOperation(DecimalException, TypeError):
-    """Enable stricter semantics for mixing floats and Decimals.
-
-    If the signal is not trapped (default), mixing floats and Decimals is
-    permitted in the Decimal() constructor, context.create_decimal() and
-    all comparison operators. Both conversion and comparisons are exact.
-    Any occurrence of a mixed operation is silently recorded by setting
-    FloatOperation in the context flags.  Explicit conversions with
-    Decimal.from_float() or context.create_decimal_from_float() do not
-    set the flag.
-
-    Otherwise (the signal is trapped), only equality comparisons and explicit
-    conversions are silent. All other mixed operations raise FloatOperation.
-    """
-
-# List of public traps and flags
-_signals = [Clamped, DivisionByZero, Inexact, Overflow, Rounded,
-            Underflow, InvalidOperation, Subnormal, FloatOperation]
-
-# Map conditions (per the spec) to signals
-_condition_map = {ConversionSyntax:InvalidOperation,
-                  DivisionImpossible:InvalidOperation,
-                  DivisionUndefined:InvalidOperation,
-                  InvalidContext:InvalidOperation}
-
-# Valid rounding modes
-_rounding_modes = (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_CEILING,
-                   ROUND_FLOOR, ROUND_UP, ROUND_HALF_DOWN, ROUND_05UP)
-
-##### Context Functions ##################################################
-
-# The getcontext() and setcontext() function manage access to a thread-local
-# current context.  Py2.4 offers direct support for thread locals.  If that
-# is not available, use threading.current_thread() which is slower but will
-# work for older Pythons.  If threads are not part of the build, create a
-# mock threading object with threading.local() returning the module namespace.
-
-try:
-    import threading
-except ImportError:
-    # Python was compiled without threads; create a mock object instead
-    class MockThreading(object):
-        def local(self, sys=sys):
-            return sys.modules[__name__]
-    threading = MockThreading()
-    del MockThreading
-
-try:
-    threading.local
-
-except AttributeError:
-
-    # To fix reloading, force it to create a new context
-    # Old contexts have different exceptions in their dicts, making problems.
-    if hasattr(threading.current_thread(), '__decimal_context__'):
-        del threading.current_thread().__decimal_context__
-
-    def setcontext(context):
-        """Set this thread's context to context."""
-        if context in (DefaultContext, BasicContext, ExtendedContext):
-            context = context.copy()
-            context.clear_flags()
-        threading.current_thread().__decimal_context__ = context
-
-    def getcontext():
-        """Returns this thread's context.
-
-        If this thread does not yet have a context, returns
-        a new context and sets this thread's context.
-        New contexts are copies of DefaultContext.
-        """
-        try:
-            return threading.current_thread().__decimal_context__
-        except AttributeError:
-            context = Context()
-            threading.current_thread().__decimal_context__ = context
-            return context
-
-else:
-
-    local = threading.local()
-    if hasattr(local, '__decimal_context__'):
-        del local.__decimal_context__
-
-    def getcontext(_local=local):
-        """Returns this thread's context.
-
-        If this thread does not yet have a context, returns
-        a new context and sets this thread's context.
-        New contexts are copies of DefaultContext.
-        """
-        try:
-            return _local.__decimal_context__
-        except AttributeError:
-            context = Context()
-            _local.__decimal_context__ = context
-            return context
-
-    def setcontext(context, _local=local):
-        """Set this thread's context to context."""
-        if context in (DefaultContext, BasicContext, ExtendedContext):
-            context = context.copy()
-            context.clear_flags()
-        _local.__decimal_context__ = context
-
-    del threading, local        # Don't contaminate the namespace
-
-def localcontext(ctx=None):
-    """Return a context manager for a copy of the supplied context
-
-    Uses a copy of the current context if no context is specified
-    The returned context manager creates a local decimal context
-    in a with statement:
-        def sin(x):
-             with localcontext() as ctx:
-                 ctx.prec += 2
-                 # Rest of sin calculation algorithm
-                 # uses a precision 2 greater than normal
-             return +s  # Convert result to normal precision
-
-         def sin(x):
-             with localcontext(ExtendedContext):
-                 # Rest of sin calculation algorithm
-                 # uses the Extended Context from the
-                 # General Decimal Arithmetic Specification
-             return +s  # Convert result to normal context
-
-    >>> setcontext(DefaultContext)
-    >>> print(getcontext().prec)
-    28
-    >>> with localcontext():
-    ...     ctx = getcontext()
-    ...     ctx.prec += 2
-    ...     print(ctx.prec)
-    ...
-    30
-    >>> with localcontext(ExtendedContext):
-    ...     print(getcontext().prec)
-    ...
-    9
-    >>> print(getcontext().prec)
-    28
-    """
-    if ctx is None: ctx = getcontext()
-    return _ContextManager(ctx)
-
-
-##### Decimal class #######################################################
-
-# Do not subclass Decimal from numbers.Real and do not register it as such
-# (because Decimals are not interoperable with floats).  See the notes in
-# numbers.py for more detail.
-
-class Decimal(object):
-    """Floating point class for decimal arithmetic."""
-
-    __slots__ = ('_exp','_int','_sign', '_is_special')
-    # Generally, the value of the Decimal instance is given by
-    #  (-1)**_sign * _int * 10**_exp
-    # Special values are signified by _is_special == True
-
-    # We're immutable, so use __new__ not __init__
-    def __new__(cls, value="0", context=None):
-        """Create a decimal point instance.
-
-        >>> Decimal('3.14')              # string input
-        Decimal('3.14')
-        >>> Decimal((0, (3, 1, 4), -2))  # tuple (sign, digit_tuple, exponent)
-        Decimal('3.14')
-        >>> Decimal(314)                 # int
-        Decimal('314')
-        >>> Decimal(Decimal(314))        # another decimal instance
-        Decimal('314')
-        >>> Decimal('  3.14  \\n')        # leading and trailing whitespace okay
-        Decimal('3.14')
-        """
-
-        # Note that the coefficient, self._int, is actually stored as
-        # a string rather than as a tuple of digits.  This speeds up
-        # the "digits to integer" and "integer to digits" conversions
-        # that are used in almost every arithmetic operation on
-        # Decimals.  This is an internal detail: the as_tuple function
-        # and the Decimal constructor still deal with tuples of
-        # digits.
-
-        self = object.__new__(cls)
-
-        # From a string
-        # REs insist on real strings, so we can too.
-        if isinstance(value, str):
-            m = _parser(value.strip())
-            if m is None:
-                if context is None:
-                    context = getcontext()
-                return context._raise_error(ConversionSyntax,
-                                "Invalid literal for Decimal: %r" % value)
-
-            if m.group('sign') == "-":
-                self._sign = 1
-            else:
-                self._sign = 0
-            intpart = m.group('int')
-            if intpart is not None:
-                # finite number
-                fracpart = m.group('frac') or ''
-                exp = int(m.group('exp') or '0')
-                self._int = str(int(intpart+fracpart))
-                self._exp = exp - len(fracpart)
-                self._is_special = False
-            else:
-                diag = m.group('diag')
-                if diag is not None:
-                    # NaN
-                    self._int = str(int(diag or '0')).lstrip('0')
-                    if m.group('signal'):
-                        self._exp = 'N'
-                    else:
-                        self._exp = 'n'
-                else:
-                    # infinity
-                    self._int = '0'
-                    self._exp = 'F'
-                self._is_special = True
-            return self
-
-        # From an integer
-        if isinstance(value, int):
-            if value >= 0:
-                self._sign = 0
-            else:
-                self._sign = 1
-            self._exp = 0
-            self._int = str(abs(value))
-            self._is_special = False
-            return self
-
-        # From another decimal
-        if isinstance(value, Decimal):
-            self._exp  = value._exp
-            self._sign = value._sign
-            self._int  = value._int
-            self._is_special  = value._is_special
-            return self
-
-        # From an internal working value
-        if isinstance(value, _WorkRep):
-            self._sign = value.sign
-            self._int = str(value.int)
-            self._exp = int(value.exp)
-            self._is_special = False
-            return self
-
-        # tuple/list conversion (possibly from as_tuple())
-        if isinstance(value, (list,tuple)):
-            if len(value) != 3:
-                raise ValueError('Invalid tuple size in creation of Decimal '
-                                 'from list or tuple.  The list or tuple '
-                                 'should have exactly three elements.')
-            # process sign.  The isinstance test rejects floats
-            if not (isinstance(value[0], int) and value[0] in (0,1)):
-                raise ValueError("Invalid sign.  The first value in the tuple "
-                                 "should be an integer; either 0 for a "
-                                 "positive number or 1 for a negative number.")
-            self._sign = value[0]
-            if value[2] == 'F':
-                # infinity: value[1] is ignored
-                self._int = '0'
-                self._exp = value[2]
-                self._is_special = True
-            else:
-                # process and validate the digits in value[1]
-                digits = []
-                for digit in value[1]:
-                    if isinstance(digit, int) and 0 <= digit <= 9:
-                        # skip leading zeros
-                        if digits or digit != 0:
-                            digits.append(digit)
-                    else:
-                        raise ValueError("The second value in the tuple must "
-                                         "be composed of integers in the range "
-                                         "0 through 9.")
-                if value[2] in ('n', 'N'):
-                    # NaN: digits form the diagnostic
-                    self._int = ''.join(map(str, digits))
-                    self._exp = value[2]
-                    self._is_special = True
-                elif isinstance(value[2], int):
-                    # finite number: digits give the coefficient
-                    self._int = ''.join(map(str, digits or [0]))
-                    self._exp = value[2]
-                    self._is_special = False
-                else:
-                    raise ValueError("The third value in the tuple must "
-                                     "be an integer, or one of the "
-                                     "strings 'F', 'n', 'N'.")
-            return self
-
-        if isinstance(value, float):
-            if context is None:
-                context = getcontext()
-            context._raise_error(FloatOperation,
-                "strict semantics for mixing floats and Decimals are "
-                "enabled")
-            value = Decimal.from_float(value)
-            self._exp  = value._exp
-            self._sign = value._sign
-            self._int  = value._int
-            self._is_special  = value._is_special
-            return self
-
-        raise TypeError("Cannot convert %r to Decimal" % value)
-
-    @classmethod
-    def from_float(cls, f):
-        """Converts a float to a decimal number, exactly.
-
-        Note that Decimal.from_float(0.1) is not the same as Decimal('0.1').
-        Since 0.1 is not exactly representable in binary floating point, the
-        value is stored as the nearest representable value which is
-        0x1.999999999999ap-4.  The exact equivalent of the value in decimal
-        is 0.1000000000000000055511151231257827021181583404541015625.
-
-        >>> Decimal.from_float(0.1)
-        Decimal('0.1000000000000000055511151231257827021181583404541015625')
-        >>> Decimal.from_float(float('nan'))
-        Decimal('NaN')
-        >>> Decimal.from_float(float('inf'))
-        Decimal('Infinity')
-        >>> Decimal.from_float(-float('inf'))
-        Decimal('-Infinity')
-        >>> Decimal.from_float(-0.0)
-        Decimal('-0')
-
-        """
-        if isinstance(f, int):                # handle integer inputs
-            return cls(f)
-        if not isinstance(f, float):
-            raise TypeError("argument must be int or float.")
-        if _math.isinf(f) or _math.isnan(f):
-            return cls(repr(f))
-        if _math.copysign(1.0, f) == 1.0:
-            sign = 0
-        else:
-            sign = 1
-        n, d = abs(f).as_integer_ratio()
-        k = d.bit_length() - 1
-        result = _dec_from_triple(sign, str(n*5**k), -k)
-        if cls is Decimal:
-            return result
-        else:
-            return cls(result)
-
-    def _isnan(self):
-        """Returns whether the number is not actually one.
-
-        0 if a number
-        1 if NaN
-        2 if sNaN
-        """
-        if self._is_special:
-            exp = self._exp
-            if exp == 'n':
-                return 1
-            elif exp == 'N':
-                return 2
-        return 0
-
-    def _isinfinity(self):
-        """Returns whether the number is infinite
-
-        0 if finite or not a number
-        1 if +INF
-        -1 if -INF
-        """
-        if self._exp == 'F':
-            if self._sign:
-                return -1
-            return 1
-        return 0
-
-    def _check_nans(self, other=None, context=None):
-        """Returns whether the number is not actually one.
-
-        if self, other are sNaN, signal
-        if self, other are NaN return nan
-        return 0
-
-        Done before operations.
-        """
-
-        self_is_nan = self._isnan()
-        if other is None:
-            other_is_nan = False
-        else:
-            other_is_nan = other._isnan()
-
-        if self_is_nan or other_is_nan:
-            if context is None:
-                context = getcontext()
-
-            if self_is_nan == 2:
-                return context._raise_error(InvalidOperation, 'sNaN',
-                                        self)
-            if other_is_nan == 2:
-                return context._raise_error(InvalidOperation, 'sNaN',
-                                        other)
-            if self_is_nan:
-                return self._fix_nan(context)
-
-            return other._fix_nan(context)
-        return 0
-
-    def _compare_check_nans(self, other, context):
-        """Version of _check_nans used for the signaling comparisons
-        compare_signal, __le__, __lt__, __ge__, __gt__.
-
-        Signal InvalidOperation if either self or other is a (quiet
-        or signaling) NaN.  Signaling NaNs take precedence over quiet
-        NaNs.
-
-        Return 0 if neither operand is a NaN.
-
-        """
-        if context is None:
-            context = getcontext()
-
-        if self._is_special or other._is_special:
-            if self.is_snan():
-                return context._raise_error(InvalidOperation,
-                                            'comparison involving sNaN',
-                                            self)
-            elif other.is_snan():
-                return context._raise_error(InvalidOperation,
-                                            'comparison involving sNaN',
-                                            other)
-            elif self.is_qnan():
-                return context._raise_error(InvalidOperation,
-                                            'comparison involving NaN',
-                                            self)
-            elif other.is_qnan():
-                return context._raise_error(InvalidOperation,
-                                            'comparison involving NaN',
-                                            other)
-        return 0
-
-    def __bool__(self):
-        """Return True if self is nonzero; otherwise return False.
-
-        NaNs and infinities are considered nonzero.
-        """
-        return self._is_special or self._int != '0'
-
-    def _cmp(self, other):
-        """Compare the two non-NaN decimal instances self and other.
-
-        Returns -1 if self < other, 0 if self == other and 1
-        if self > other.  This routine is for internal use only."""
-
-        if self._is_special or other._is_special:
-            self_inf = self._isinfinity()
-            other_inf = other._isinfinity()
-            if self_inf == other_inf:
-                return 0
-            elif self_inf < other_inf:
-                return -1
-            else:
-                return 1
-
-        # check for zeros;  Decimal('0') == Decimal('-0')
-        if not self:
-            if not other:
-                return 0
-            else:
-                return -((-1)**other._sign)
-        if not other:
-            return (-1)**self._sign
-
-        # If different signs, neg one is less
-        if other._sign < self._sign:
-            return -1
-        if self._sign < other._sign:
-            return 1
-
-        self_adjusted = self.adjusted()
-        other_adjusted = other.adjusted()
-        if self_adjusted == other_adjusted:
-            self_padded = self._int + '0'*(self._exp - other._exp)
-            other_padded = other._int + '0'*(other._exp - self._exp)
-            if self_padded == other_padded:
-                return 0
-            elif self_padded < other_padded:
-                return -(-1)**self._sign
-            else:
-                return (-1)**self._sign
-        elif self_adjusted > other_adjusted:
-            return (-1)**self._sign
-        else: # self_adjusted < other_adjusted
-            return -((-1)**self._sign)
-
-    # Note: The Decimal standard doesn't cover rich comparisons for
-    # Decimals.  In particular, the specification is silent on the
-    # subject of what should happen for a comparison involving a NaN.
-    # We take the following approach:
-    #
-    #   == comparisons involving a quiet NaN always return False
-    #   != comparisons involving a quiet NaN always return True
-    #   == or != comparisons involving a signaling NaN signal
-    #      InvalidOperation, and return False or True as above if the
-    #      InvalidOperation is not trapped.
-    #   <, >, <= and >= comparisons involving a (quiet or signaling)
-    #      NaN signal InvalidOperation, and return False if the
-    #      InvalidOperation is not trapped.
-    #
-    # This behavior is designed to conform as closely as possible to
-    # that specified by IEEE 754.
-
-    def __eq__(self, other, context=None):
-        self, other = _convert_for_comparison(self, other, equality_op=True)
-        if other is NotImplemented:
-            return other
-        if self._check_nans(other, context):
-            return False
-        return self._cmp(other) == 0
-
-    def __ne__(self, other, context=None):
-        self, other = _convert_for_comparison(self, other, equality_op=True)
-        if other is NotImplemented:
-            return other
-        if self._check_nans(other, context):
-            return True
-        return self._cmp(other) != 0
-
-
-    def __lt__(self, other, context=None):
-        self, other = _convert_for_comparison(self, other)
-        if other is NotImplemented:
-            return other
-        ans = self._compare_check_nans(other, context)
-        if ans:
-            return False
-        return self._cmp(other) < 0
-
-    def __le__(self, other, context=None):
-        self, other = _convert_for_comparison(self, other)
-        if other is NotImplemented:
-            return other
-        ans = self._compare_check_nans(other, context)
-        if ans:
-            return False
-        return self._cmp(other) <= 0
-
-    def __gt__(self, other, context=None):
-        self, other = _convert_for_comparison(self, other)
-        if other is NotImplemented:
-            return other
-        ans = self._compare_check_nans(other, context)
-        if ans:
-            return False
-        return self._cmp(other) > 0
-
-    def __ge__(self, other, context=None):
-        self, other = _convert_for_comparison(self, other)
-        if other is NotImplemented:
-            return other
-        ans = self._compare_check_nans(other, context)
-        if ans:
-            return False
-        return self._cmp(other) >= 0
-
-    def compare(self, other, context=None):
-        """Compare self to other.  Return a decimal value:
-
-        a or b is a NaN ==> Decimal('NaN')
-        a < b           ==> Decimal('-1')
-        a == b          ==> Decimal('0')
-        a > b           ==> Decimal('1')
-        """
-        other = _convert_other(other, raiseit=True)
-
-        # Compare(NaN, NaN) = NaN
-        if (self._is_special or other and other._is_special):
-            ans = self._check_nans(other, context)
-            if ans:
-                return ans
-
-        return Decimal(self._cmp(other))
-
-    def __hash__(self):
-        """x.__hash__() <==> hash(x)"""
-
-        # In order to make sure that the hash of a Decimal instance
-        # agrees with the hash of a numerically equal integer, float
-        # or Fraction, we follow the rules for numeric hashes outlined
-        # in the documentation.  (See library docs, 'Built-in Types').
-        if self._is_special:
-            if self.is_snan():
-                raise TypeError('Cannot hash a signaling NaN value.')
-            elif self.is_nan():
-                return _PyHASH_NAN
-            else:
-                if self._sign:
-                    return -_PyHASH_INF
-                else:
-                    return _PyHASH_INF
-
-        if self._exp >= 0:
-            exp_hash = pow(10, self._exp, _PyHASH_MODULUS)
-        else:
-            exp_hash = pow(_PyHASH_10INV, -self._exp, _PyHASH_MODULUS)
-        hash_ = int(self._int) * exp_hash % _PyHASH_MODULUS
-        ans = hash_ if self >= 0 else -hash_
-        return -2 if ans == -1 else ans
-
-    def as_tuple(self):
-        """Represents the number as a triple tuple.
-
-        To show the internals exactly as they are.
-        """
-        return DecimalTuple(self._sign, tuple(map(int, self._int)), self._exp)
-
-    def __repr__(self):
-        """Represents the number as an instance of Decimal."""
-        # Invariant:  eval(repr(d)) == d
-        return "Decimal('%s')" % str(self)
-
-    def __str__(self, eng=False, context=None):
-        """Return string representation of the number in scientific notation.
-
-        Captures all of the information in the underlying representation.
-        """
-
-        sign = ['', '-'][self._sign]
-        if self._is_special:
-            if self._exp == 'F':
-                return sign + 'Infinity'
-            elif self._exp == 'n':
-                return sign + 'NaN' + self._int
-            else: # self._exp == 'N'
-                return sign + 'sNaN' + self._int
-
-        # number of digits of self._int to left of decimal point
-        leftdigits = self._exp + len(self._int)
-
-        # dotplace is number of digits of self._int to the left of the
-        # decimal point in the mantissa of the output string (that is,
-        # after adjusting the exponent)
-        if self._exp <= 0 and leftdigits > -6:
-            # no exponent required
-            dotplace = leftdigits
-        elif not eng:
-            # usual scientific notation: 1 digit on left of the point
-            dotplace = 1
-        elif self._int == '0':
-            # engineering notation, zero
-            dotplace = (leftdigits + 1) % 3 - 1
-        else:
-            # engineering notation, nonzero
-            dotplace = (leftdigits - 1) % 3 + 1
-
-        if dotplace <= 0:
-            intpart = '0'
-            fracpart = '.' + '0'*(-dotplace) + self._int
-        elif dotplace >= len(self._int):
-            intpart = self._int+'0'*(dotplace-len(self._int))
-            fracpart = ''
-        else:
-            intpart = self._int[:dotplace]
-            fracpart = '.' + self._int[dotplace:]
-        if leftdigits == dotplace:
-            exp = ''
-        else:
-            if context is None:
-                context = getcontext()
-            exp = ['e', 'E'][context.capitals] + "%+d" % (leftdigits-dotplace)
-
-        return sign + intpart + fracpart + exp
-
-    def to_eng_string(self, context=None):
-        """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.
-
-        Same rules for when in exponential and when as a value as in __str__.
-        """
-        return self.__str__(eng=True, context=context)
-
-    def __neg__(self, context=None):
-        """Returns a copy with the sign switched.
-
-        Rounds, if it has reason.
-        """
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-
-        if context is None:
-            context = getcontext()
-
-        if not self and context.rounding != ROUND_FLOOR:
-            # -Decimal('0') is Decimal('0'), not Decimal('-0'), except
-            # in ROUND_FLOOR rounding mode.
-            ans = self.copy_abs()
-        else:
-            ans = self.copy_negate()
-
-        return ans._fix(context)
-
-    def __pos__(self, context=None):
-        """Returns a copy, unless it is a sNaN.
-
-        Rounds the number (if more then precision digits)
-        """
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-
-        if context is None:
-            context = getcontext()
-
-        if not self and context.rounding != ROUND_FLOOR:
-            # + (-0) = 0, except in ROUND_FLOOR rounding mode.
-            ans = self.copy_abs()
-        else:
-            ans = Decimal(self)
-
-        return ans._fix(context)
-
-    def __abs__(self, round=True, context=None):
-        """Returns the absolute value of self.
-
-        If the keyword argument 'round' is false, do not round.  The
-        expression self.__abs__(round=False) is equivalent to
-        self.copy_abs().
-        """
-        if not round:
-            return self.copy_abs()
-
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-
-        if self._sign:
-            ans = self.__neg__(context=context)
-        else:
-            ans = self.__pos__(context=context)
-
-        return ans
-
-    def __add__(self, other, context=None):
-        """Returns self + other.
-
-        -INF + INF (or the reverse) cause InvalidOperation errors.
-        """
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if context is None:
-            context = getcontext()
-
-        if self._is_special or other._is_special:
-            ans = self._check_nans(other, context)
-            if ans:
-                return ans
-
-            if self._isinfinity():
-                # If both INF, same sign => same as both, opposite => error.
-                if self._sign != other._sign and other._isinfinity():
-                    return context._raise_error(InvalidOperation, '-INF + INF')
-                return Decimal(self)
-            if other._isinfinity():
-                return Decimal(other)  # Can't both be infinity here
-
-        exp = min(self._exp, other._exp)
-        negativezero = 0
-        if context.rounding == ROUND_FLOOR and self._sign != other._sign:
-            # If the answer is 0, the sign should be negative, in this case.
-            negativezero = 1
-
-        if not self and not other:
-            sign = min(self._sign, other._sign)
-            if negativezero:
-                sign = 1
-            ans = _dec_from_triple(sign, '0', exp)
-            ans = ans._fix(context)
-            return ans
-        if not self:
-            exp = max(exp, other._exp - context.prec-1)
-            ans = other._rescale(exp, context.rounding)
-            ans = ans._fix(context)
-            return ans
-        if not other:
-            exp = max(exp, self._exp - context.prec-1)
-            ans = self._rescale(exp, context.rounding)
-            ans = ans._fix(context)
-            return ans
-
-        op1 = _WorkRep(self)
-        op2 = _WorkRep(other)
-        op1, op2 = _normalize(op1, op2, context.prec)
-
-        result = _WorkRep()
-        if op1.sign != op2.sign:
-            # Equal and opposite
-            if op1.int == op2.int:
-                ans = _dec_from_triple(negativezero, '0', exp)
-                ans = ans._fix(context)
-                return ans
-            if op1.int < op2.int:
-                op1, op2 = op2, op1
-                # OK, now abs(op1) > abs(op2)
-            if op1.sign == 1:
-                result.sign = 1
-                op1.sign, op2.sign = op2.sign, op1.sign
-            else:
-                result.sign = 0
-                # So we know the sign, and op1 > 0.
-        elif op1.sign == 1:
-            result.sign = 1
-            op1.sign, op2.sign = (0, 0)
-        else:
-            result.sign = 0
-        # Now, op1 > abs(op2) > 0
-
-        if op2.sign == 0:
-            result.int = op1.int + op2.int
-        else:
-            result.int = op1.int - op2.int
-
-        result.exp = op1.exp
-        ans = Decimal(result)
-        ans = ans._fix(context)
-        return ans
-
-    __radd__ = __add__
-
-    def __sub__(self, other, context=None):
-        """Return self - other"""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if self._is_special or other._is_special:
-            ans = self._check_nans(other, context=context)
-            if ans:
-                return ans
-
-        # self - other is computed as self + other.copy_negate()
-        return self.__add__(other.copy_negate(), context=context)
-
-    def __rsub__(self, other, context=None):
-        """Return other - self"""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        return other.__sub__(self, context=context)
-
-    def __mul__(self, other, context=None):
-        """Return self * other.
-
-        (+-) INF * 0 (or its reverse) raise InvalidOperation.
-        """
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if context is None:
-            context = getcontext()
-
-        resultsign = self._sign ^ other._sign
-
-        if self._is_special or other._is_special:
-            ans = self._check_nans(other, context)
-            if ans:
-                return ans
-
-            if self._isinfinity():
-                if not other:
-                    return context._raise_error(InvalidOperation, '(+-)INF * 0')
-                return _SignedInfinity[resultsign]
-
-            if other._isinfinity():
-                if not self:
-                    return context._raise_error(InvalidOperation, '0 * (+-)INF')
-                return _SignedInfinity[resultsign]
-
-        resultexp = self._exp + other._exp
-
-        # Special case for multiplying by zero
-        if not self or not other:
-            ans = _dec_from_triple(resultsign, '0', resultexp)
-            # Fixing in case the exponent is out of bounds
-            ans = ans._fix(context)
-            return ans
-
-        # Special case for multiplying by power of 10
-        if self._int == '1':
-            ans = _dec_from_triple(resultsign, other._int, resultexp)
-            ans = ans._fix(context)
-            return ans
-        if other._int == '1':
-            ans = _dec_from_triple(resultsign, self._int, resultexp)
-            ans = ans._fix(context)
-            return ans
-
-        op1 = _WorkRep(self)
-        op2 = _WorkRep(other)
-
-        ans = _dec_from_triple(resultsign, str(op1.int * op2.int), resultexp)
-        ans = ans._fix(context)
-
-        return ans
-    __rmul__ = __mul__
-
-    def __truediv__(self, other, context=None):
-        """Return self / other."""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return NotImplemented
-
-        if context is None:
-            context = getcontext()
-
-        sign = self._sign ^ other._sign
-
-        if self._is_special or other._is_special:
-            ans = self._check_nans(other, context)
-            if ans:
-                return ans
-
-            if self._isinfinity() and other._isinfinity():
-                return context._raise_error(InvalidOperation, '(+-)INF/(+-)INF')
-
-            if self._isinfinity():
-                return _SignedInfinity[sign]
-
-            if other._isinfinity():
-                context._raise_error(Clamped, 'Division by infinity')
-                return _dec_from_triple(sign, '0', context.Etiny())
-
-        # Special cases for zeroes
-        if not other:
-            if not self:
-                return context._raise_error(DivisionUndefined, '0 / 0')
-            return context._raise_error(DivisionByZero, 'x / 0', sign)
-
-        if not self:
-            exp = self._exp - other._exp
-            coeff = 0
-        else:
-            # OK, so neither = 0, INF or NaN
-            shift = len(other._int) - len(self._int) + context.prec + 1
-            exp = self._exp - other._exp - shift
-            op1 = _WorkRep(self)
-            op2 = _WorkRep(other)
-            if shift >= 0:
-                coeff, remainder = divmod(op1.int * 10**shift, op2.int)
-            else:
-                coeff, remainder = divmod(op1.int, op2.int * 10**-shift)
-            if remainder:
-                # result is not exact; adjust to ensure correct rounding
-                if coeff % 5 == 0:
-                    coeff += 1
-            else:
-                # result is exact; get as close to ideal exponent as possible
-                ideal_exp = self._exp - other._exp
-                while exp < ideal_exp and coeff % 10 == 0:
-                    coeff //= 10
-                    exp += 1
-
-        ans = _dec_from_triple(sign, str(coeff), exp)
-        return ans._fix(context)
-
-    def _divide(self, other, context):
-        """Return (self // other, self % other), to context.prec precision.
-
-        Assumes that neither self nor other is a NaN, that self is not
-        infinite and that other is nonzero.
-        """
-        sign = self._sign ^ other._sign
-        if other._isinfinity():
-            ideal_exp = self._exp
-        else:
-            ideal_exp = min(self._exp, other._exp)
-
-        expdiff = self.adjusted() - other.adjusted()
-        if not self or other._isinfinity() or expdiff <= -2:
-            return (_dec_from_triple(sign, '0', 0),
-                    self._rescale(ideal_exp, context.rounding))
-        if expdiff <= context.prec:
-            op1 = _WorkRep(self)
-            op2 = _WorkRep(other)
-            if op1.exp >= op2.exp:
-                op1.int *= 10**(op1.exp - op2.exp)
-            else:
-                op2.int *= 10**(op2.exp - op1.exp)
-            q, r = divmod(op1.int, op2.int)
-            if q < 10**context.prec:
-                return (_dec_from_triple(sign, str(q), 0),
-                        _dec_from_triple(self._sign, str(r), ideal_exp))
-
-        # Here the quotient is too large to be representable
-        ans = context._raise_error(DivisionImpossible,
-                                   'quotient too large in //, % or divmod')
-        return ans, ans
-
-    def __rtruediv__(self, other, context=None):
-        """Swaps self/other and returns __truediv__."""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-        return other.__truediv__(self, context=context)
-
-    def __divmod__(self, other, context=None):
-        """
-        Return (self // other, self % other)
-        """
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if context is None:
-            context = getcontext()
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return (ans, ans)
-
-        sign = self._sign ^ other._sign
-        if self._isinfinity():
-            if other._isinfinity():
-                ans = context._raise_error(InvalidOperation, 'divmod(INF, INF)')
-                return ans, ans
-            else:
-                return (_SignedInfinity[sign],
-                        context._raise_error(InvalidOperation, 'INF % x'))
-
-        if not other:
-            if not self:
-                ans = context._raise_error(DivisionUndefined, 'divmod(0, 0)')
-                return ans, ans
-            else:
-                return (context._raise_error(DivisionByZero, 'x // 0', sign),
-                        context._raise_error(InvalidOperation, 'x % 0'))
-
-        quotient, remainder = self._divide(other, context)
-        remainder = remainder._fix(context)
-        return quotient, remainder
-
-    def __rdivmod__(self, other, context=None):
-        """Swaps self/other and returns __divmod__."""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-        return other.__divmod__(self, context=context)
-
-    def __mod__(self, other, context=None):
-        """
-        self % other
-        """
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if context is None:
-            context = getcontext()
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        if self._isinfinity():
-            return context._raise_error(InvalidOperation, 'INF % x')
-        elif not other:
-            if self:
-                return context._raise_error(InvalidOperation, 'x % 0')
-            else:
-                return context._raise_error(DivisionUndefined, '0 % 0')
-
-        remainder = self._divide(other, context)[1]
-        remainder = remainder._fix(context)
-        return remainder
-
-    def __rmod__(self, other, context=None):
-        """Swaps self/other and returns __mod__."""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-        return other.__mod__(self, context=context)
-
-    def remainder_near(self, other, context=None):
-        """
-        Remainder nearest to 0-  abs(remainder-near) <= other/2
-        """
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        # self == +/-infinity -> InvalidOperation
-        if self._isinfinity():
-            return context._raise_error(InvalidOperation,
-                                        'remainder_near(infinity, x)')
-
-        # other == 0 -> either InvalidOperation or DivisionUndefined
-        if not other:
-            if self:
-                return context._raise_error(InvalidOperation,
-                                            'remainder_near(x, 0)')
-            else:
-                return context._raise_error(DivisionUndefined,
-                                            'remainder_near(0, 0)')
-
-        # other = +/-infinity -> remainder = self
-        if other._isinfinity():
-            ans = Decimal(self)
-            return ans._fix(context)
-
-        # self = 0 -> remainder = self, with ideal exponent
-        ideal_exponent = min(self._exp, other._exp)
-        if not self:
-            ans = _dec_from_triple(self._sign, '0', ideal_exponent)
-            return ans._fix(context)
-
-        # catch most cases of large or small quotient
-        expdiff = self.adjusted() - other.adjusted()
-        if expdiff >= context.prec + 1:
-            # expdiff >= prec+1 => abs(self/other) > 10**prec
-            return context._raise_error(DivisionImpossible)
-        if expdiff <= -2:
-            # expdiff <= -2 => abs(self/other) < 0.1
-            ans = self._rescale(ideal_exponent, context.rounding)
-            return ans._fix(context)
-
-        # adjust both arguments to have the same exponent, then divide
-        op1 = _WorkRep(self)
-        op2 = _WorkRep(other)
-        if op1.exp >= op2.exp:
-            op1.int *= 10**(op1.exp - op2.exp)
-        else:
-            op2.int *= 10**(op2.exp - op1.exp)
-        q, r = divmod(op1.int, op2.int)
-        # remainder is r*10**ideal_exponent; other is +/-op2.int *
-        # 10**ideal_exponent.   Apply correction to ensure that
-        # abs(remainder) <= abs(other)/2
-        if 2*r + (q&1) > op2.int:
-            r -= op2.int
-            q += 1
-
-        if q >= 10**context.prec:
-            return context._raise_error(DivisionImpossible)
-
-        # result has same sign as self unless r is negative
-        sign = self._sign
-        if r < 0:
-            sign = 1-sign
-            r = -r
-
-        ans = _dec_from_triple(sign, str(r), ideal_exponent)
-        return ans._fix(context)
-
-    def __floordiv__(self, other, context=None):
-        """self // other"""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if context is None:
-            context = getcontext()
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        if self._isinfinity():
-            if other._isinfinity():
-                return context._raise_error(InvalidOperation, 'INF // INF')
-            else:
-                return _SignedInfinity[self._sign ^ other._sign]
-
-        if not other:
-            if self:
-                return context._raise_error(DivisionByZero, 'x // 0',
-                                            self._sign ^ other._sign)
-            else:
-                return context._raise_error(DivisionUndefined, '0 // 0')
-
-        return self._divide(other, context)[0]
-
-    def __rfloordiv__(self, other, context=None):
-        """Swaps self/other and returns __floordiv__."""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-        return other.__floordiv__(self, context=context)
-
-    def __float__(self):
-        """Float representation."""
-        if self._isnan():
-            if self.is_snan():
-                raise ValueError("Cannot convert signaling NaN to float")
-            s = "-nan" if self._sign else "nan"
-        else:
-            s = str(self)
-        return float(s)
-
-    def __int__(self):
-        """Converts self to an int, truncating if necessary."""
-        if self._is_special:
-            if self._isnan():
-                raise ValueError("Cannot convert NaN to integer")
-            elif self._isinfinity():
-                raise OverflowError("Cannot convert infinity to integer")
-        s = (-1)**self._sign
-        if self._exp >= 0:
-            return s*int(self._int)*10**self._exp
-        else:
-            return s*int(self._int[:self._exp] or '0')
-
-    __trunc__ = __int__
-
-    def real(self):
-        return self
-    real = property(real)
-
-    def imag(self):
-        return Decimal(0)
-    imag = property(imag)
-
-    def conjugate(self):
-        return self
-
-    def __complex__(self):
-        return complex(float(self))
-
-    def _fix_nan(self, context):
-        """Decapitate the payload of a NaN to fit the context"""
-        payload = self._int
-
-        # maximum length of payload is precision if clamp=0,
-        # precision-1 if clamp=1.
-        max_payload_len = context.prec - context.clamp
-        if len(payload) > max_payload_len:
-            payload = payload[len(payload)-max_payload_len:].lstrip('0')
-            return _dec_from_triple(self._sign, payload, self._exp, True)
-        return Decimal(self)
-
-    def _fix(self, context):
-        """Round if it is necessary to keep self within prec precision.
-
-        Rounds and fixes the exponent.  Does not raise on a sNaN.
-
-        Arguments:
-        self - Decimal instance
-        context - context used.
-        """
-
-        if self._is_special:
-            if self._isnan():
-                # decapitate payload if necessary
-                return self._fix_nan(context)
-            else:
-                # self is +/-Infinity; return unaltered
-                return Decimal(self)
-
-        # if self is zero then exponent should be between Etiny and
-        # Emax if clamp==0, and between Etiny and Etop if clamp==1.
-        Etiny = context.Etiny()
-        Etop = context.Etop()
-        if not self:
-            exp_max = [context.Emax, Etop][context.clamp]
-            new_exp = min(max(self._exp, Etiny), exp_max)
-            if new_exp != self._exp:
-                context._raise_error(Clamped)
-                return _dec_from_triple(self._sign, '0', new_exp)
-            else:
-                return Decimal(self)
-
-        # exp_min is the smallest allowable exponent of the result,
-        # equal to max(self.adjusted()-context.prec+1, Etiny)
-        exp_min = len(self._int) + self._exp - context.prec
-        if exp_min > Etop:
-            # overflow: exp_min > Etop iff self.adjusted() > Emax
-            ans = context._raise_error(Overflow, 'above Emax', self._sign)
-            context._raise_error(Inexact)
-            context._raise_error(Rounded)
-            return ans
-
-        self_is_subnormal = exp_min < Etiny
-        if self_is_subnormal:
-            exp_min = Etiny
-
-        # round if self has too many digits
-        if self._exp < exp_min:
-            digits = len(self._int) + self._exp - exp_min
-            if digits < 0:
-                self = _dec_from_triple(self._sign, '1', exp_min-1)
-                digits = 0
-            rounding_method = self._pick_rounding_function[context.rounding]
-            changed = rounding_method(self, digits)
-            coeff = self._int[:digits] or '0'
-            if changed > 0:
-                coeff = str(int(coeff)+1)
-                if len(coeff) > context.prec:
-                    coeff = coeff[:-1]
-                    exp_min += 1
-
-            # check whether the rounding pushed the exponent out of range
-            if exp_min > Etop:
-                ans = context._raise_error(Overflow, 'above Emax', self._sign)
-            else:
-                ans = _dec_from_triple(self._sign, coeff, exp_min)
-
-            # raise the appropriate signals, taking care to respect
-            # the precedence described in the specification
-            if changed and self_is_subnormal:
-                context._raise_error(Underflow)
-            if self_is_subnormal:
-                context._raise_error(Subnormal)
-            if changed:
-                context._raise_error(Inexact)
-            context._raise_error(Rounded)
-            if not ans:
-                # raise Clamped on underflow to 0
-                context._raise_error(Clamped)
-            return ans
-
-        if self_is_subnormal:
-            context._raise_error(Subnormal)
-
-        # fold down if clamp == 1 and self has too few digits
-        if context.clamp == 1 and self._exp > Etop:
-            context._raise_error(Clamped)
-            self_padded = self._int + '0'*(self._exp - Etop)
-            return _dec_from_triple(self._sign, self_padded, Etop)
-
-        # here self was representable to begin with; return unchanged
-        return Decimal(self)
-
-    # for each of the rounding functions below:
-    #   self is a finite, nonzero Decimal
-    #   prec is an integer satisfying 0 <= prec < len(self._int)
-    #
-    # each function returns either -1, 0, or 1, as follows:
-    #   1 indicates that self should be rounded up (away from zero)
-    #   0 indicates that self should be truncated, and that all the
-    #     digits to be truncated are zeros (so the value is unchanged)
-    #  -1 indicates that there are nonzero digits to be truncated
-
-    def _round_down(self, prec):
-        """Also known as round-towards-0, truncate."""
-        if _all_zeros(self._int, prec):
-            return 0
-        else:
-            return -1
-
-    def _round_up(self, prec):
-        """Rounds away from 0."""
-        return -self._round_down(prec)
-
-    def _round_half_up(self, prec):
-        """Rounds 5 up (away from 0)"""
-        if self._int[prec] in '56789':
-            return 1
-        elif _all_zeros(self._int, prec):
-            return 0
-        else:
-            return -1
-
-    def _round_half_down(self, prec):
-        """Round 5 down"""
-        if _exact_half(self._int, prec):
-            return -1
-        else:
-            return self._round_half_up(prec)
-
-    def _round_half_even(self, prec):
-        """Round 5 to even, rest to nearest."""
-        if _exact_half(self._int, prec) and \
-                (prec == 0 or self._int[prec-1] in '02468'):
-            return -1
-        else:
-            return self._round_half_up(prec)
-
-    def _round_ceiling(self, prec):
-        """Rounds up (not away from 0 if negative.)"""
-        if self._sign:
-            return self._round_down(prec)
-        else:
-            return -self._round_down(prec)
-
-    def _round_floor(self, prec):
-        """Rounds down (not towards 0 if negative)"""
-        if not self._sign:
-            return self._round_down(prec)
-        else:
-            return -self._round_down(prec)
-
-    def _round_05up(self, prec):
-        """Round down unless digit prec-1 is 0 or 5."""
-        if prec and self._int[prec-1] not in '05':
-            return self._round_down(prec)
-        else:
-            return -self._round_down(prec)
-
-    _pick_rounding_function = dict(
-        ROUND_DOWN = _round_down,
-        ROUND_UP = _round_up,
-        ROUND_HALF_UP = _round_half_up,
-        ROUND_HALF_DOWN = _round_half_down,
-        ROUND_HALF_EVEN = _round_half_even,
-        ROUND_CEILING = _round_ceiling,
-        ROUND_FLOOR = _round_floor,
-        ROUND_05UP = _round_05up,
-    )
-
-    def __round__(self, n=None):
-        """Round self to the nearest integer, or to a given precision.
-
-        If only one argument is supplied, round a finite Decimal
-        instance self to the nearest integer.  If self is infinite or
-        a NaN then a Python exception is raised.  If self is finite
-        and lies exactly halfway between two integers then it is
-        rounded to the integer with even last digit.
-
-        >>> round(Decimal('123.456'))
-        123
-        >>> round(Decimal('-456.789'))
-        -457
-        >>> round(Decimal('-3.0'))
-        -3
-        >>> round(Decimal('2.5'))
-        2
-        >>> round(Decimal('3.5'))
-        4
-        >>> round(Decimal('Inf'))
-        Traceback (most recent call last):
-          ...
-        OverflowError: cannot round an infinity
-        >>> round(Decimal('NaN'))
-        Traceback (most recent call last):
-          ...
-        ValueError: cannot round a NaN
-
-        If a second argument n is supplied, self is rounded to n
-        decimal places using the rounding mode for the current
-        context.
-
-        For an integer n, round(self, -n) is exactly equivalent to
-        self.quantize(Decimal('1En')).
-
-        >>> round(Decimal('123.456'), 0)
-        Decimal('123')
-        >>> round(Decimal('123.456'), 2)
-        Decimal('123.46')
-        >>> round(Decimal('123.456'), -2)
-        Decimal('1E+2')
-        >>> round(Decimal('-Infinity'), 37)
-        Decimal('NaN')
-        >>> round(Decimal('sNaN123'), 0)
-        Decimal('NaN123')
-
-        """
-        if n is not None:
-            # two-argument form: use the equivalent quantize call
-            if not isinstance(n, int):
-                raise TypeError('Second argument to round should be integral')
-            exp = _dec_from_triple(0, '1', -n)
-            return self.quantize(exp)
-
-        # one-argument form
-        if self._is_special:
-            if self.is_nan():
-                raise ValueError("cannot round a NaN")
-            else:
-                raise OverflowError("cannot round an infinity")
-        return int(self._rescale(0, ROUND_HALF_EVEN))
-
-    def __floor__(self):
-        """Return the floor of self, as an integer.
-
-        For a finite Decimal instance self, return the greatest
-        integer n such that n <= self.  If self is infinite or a NaN
-        then a Python exception is raised.
-
-        """
-        if self._is_special:
-            if self.is_nan():
-                raise ValueError("cannot round a NaN")
-            else:
-                raise OverflowError("cannot round an infinity")
-        return int(self._rescale(0, ROUND_FLOOR))
-
-    def __ceil__(self):
-        """Return the ceiling of self, as an integer.
-
-        For a finite Decimal instance self, return the least integer n
-        such that n >= self.  If self is infinite or a NaN then a
-        Python exception is raised.
-
-        """
-        if self._is_special:
-            if self.is_nan():
-                raise ValueError("cannot round a NaN")
-            else:
-                raise OverflowError("cannot round an infinity")
-        return int(self._rescale(0, ROUND_CEILING))
-
-    def fma(self, other, third, context=None):
-        """Fused multiply-add.
-
-        Returns self*other+third with no rounding of the intermediate
-        product self*other.
-
-        self and other are multiplied together, with no rounding of
-        the result.  The third operand is then added to the result,
-        and a single final rounding is performed.
-        """
-
-        other = _convert_other(other, raiseit=True)
-        third = _convert_other(third, raiseit=True)
-
-        # compute product; raise InvalidOperation if either operand is
-        # a signaling NaN or if the product is zero times infinity.
-        if self._is_special or other._is_special:
-            if context is None:
-                context = getcontext()
-            if self._exp == 'N':
-                return context._raise_error(InvalidOperation, 'sNaN', self)
-            if other._exp == 'N':
-                return context._raise_error(InvalidOperation, 'sNaN', other)
-            if self._exp == 'n':
-                product = self
-            elif other._exp == 'n':
-                product = other
-            elif self._exp == 'F':
-                if not other:
-                    return context._raise_error(InvalidOperation,
-                                                'INF * 0 in fma')
-                product = _SignedInfinity[self._sign ^ other._sign]
-            elif other._exp == 'F':
-                if not self:
-                    return context._raise_error(InvalidOperation,
-                                                '0 * INF in fma')
-                product = _SignedInfinity[self._sign ^ other._sign]
-        else:
-            product = _dec_from_triple(self._sign ^ other._sign,
-                                       str(int(self._int) * int(other._int)),
-                                       self._exp + other._exp)
-
-        return product.__add__(third, context)
-
-    def _power_modulo(self, other, modulo, context=None):
-        """Three argument version of __pow__"""
-
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-        modulo = _convert_other(modulo)
-        if modulo is NotImplemented:
-            return modulo
-
-        if context is None:
-            context = getcontext()
-
-        # deal with NaNs: if there are any sNaNs then first one wins,
-        # (i.e. behaviour for NaNs is identical to that of fma)
-        self_is_nan = self._isnan()
-        other_is_nan = other._isnan()
-        modulo_is_nan = modulo._isnan()
-        if self_is_nan or other_is_nan or modulo_is_nan:
-            if self_is_nan == 2:
-                return context._raise_error(InvalidOperation, 'sNaN',
-                                        self)
-            if other_is_nan == 2:
-                return context._raise_error(InvalidOperation, 'sNaN',
-                                        other)
-            if modulo_is_nan == 2:
-                return context._raise_error(InvalidOperation, 'sNaN',
-                                        modulo)
-            if self_is_nan:
-                return self._fix_nan(context)
-            if other_is_nan:
-                return other._fix_nan(context)
-            return modulo._fix_nan(context)
-
-        # check inputs: we apply same restrictions as Python's pow()
-        if not (self._isinteger() and
-                other._isinteger() and
-                modulo._isinteger()):
-            return context._raise_error(InvalidOperation,
-                                        'pow() 3rd argument not allowed '
-                                        'unless all arguments are integers')
-        if other < 0:
-            return context._raise_error(InvalidOperation,
-                                        'pow() 2nd argument cannot be '
-                                        'negative when 3rd argument specified')
-        if not modulo:
-            return context._raise_error(InvalidOperation,
-                                        'pow() 3rd argument cannot be 0')
-
-        # additional restriction for decimal: the modulus must be less
-        # than 10**prec in absolute value
-        if modulo.adjusted() >= context.prec:
-            return context._raise_error(InvalidOperation,
-                                        'insufficient precision: pow() 3rd '
-                                        'argument must not have more than '
-                                        'precision digits')
-
-        # define 0**0 == NaN, for consistency with two-argument pow
-        # (even though it hurts!)
-        if not other and not self:
-            return context._raise_error(InvalidOperation,
-                                        'at least one of pow() 1st argument '
-                                        'and 2nd argument must be nonzero ;'
-                                        '0**0 is not defined')
-
-        # compute sign of result
-        if other._iseven():
-            sign = 0
-        else:
-            sign = self._sign
-
-        # convert modulo to a Python integer, and self and other to
-        # Decimal integers (i.e. force their exponents to be >= 0)
-        modulo = abs(int(modulo))
-        base = _WorkRep(self.to_integral_value())
-        exponent = _WorkRep(other.to_integral_value())
-
-        # compute result using integer pow()
-        base = (base.int % modulo * pow(10, base.exp, modulo)) % modulo
-        for i in range(exponent.exp):
-            base = pow(base, 10, modulo)
-        base = pow(base, exponent.int, modulo)
-
-        return _dec_from_triple(sign, str(base), 0)
-
-    def _power_exact(self, other, p):
-        """Attempt to compute self**other exactly.
-
-        Given Decimals self and other and an integer p, attempt to
-        compute an exact result for the power self**other, with p
-        digits of precision.  Return None if self**other is not
-        exactly representable in p digits.
-
-        Assumes that elimination of special cases has already been
-        performed: self and other must both be nonspecial; self must
-        be positive and not numerically equal to 1; other must be
-        nonzero.  For efficiency, other._exp should not be too large,
-        so that 10**abs(other._exp) is a feasible calculation."""
-
-        # In the comments below, we write x for the value of self and y for the
-        # value of other.  Write x = xc*10**xe and abs(y) = yc*10**ye, with xc
-        # and yc positive integers not divisible by 10.
-
-        # The main purpose of this method is to identify the *failure*
-        # of x**y to be exactly representable with as little effort as
-        # possible.  So we look for cheap and easy tests that
-        # eliminate the possibility of x**y being exact.  Only if all
-        # these tests are passed do we go on to actually compute x**y.
-
-        # Here's the main idea.  Express y as a rational number m/n, with m and
-        # n relatively prime and n>0.  Then for x**y to be exactly
-        # representable (at *any* precision), xc must be the nth power of a
-        # positive integer and xe must be divisible by n.  If y is negative
-        # then additionally xc must be a power of either 2 or 5, hence a power
-        # of 2**n or 5**n.
-        #
-        # There's a limit to how small |y| can be: if y=m/n as above
-        # then:
-        #
-        #  (1) if xc != 1 then for the result to be representable we
-        #      need xc**(1/n) >= 2, and hence also xc**|y| >= 2.  So
-        #      if |y| <= 1/nbits(xc) then xc < 2**nbits(xc) <=
-        #      2**(1/|y|), hence xc**|y| < 2 and the result is not
-        #      representable.
-        #
-        #  (2) if xe != 0, |xe|*(1/n) >= 1, so |xe|*|y| >= 1.  Hence if
-        #      |y| < 1/|xe| then the result is not representable.
-        #
-        # Note that since x is not equal to 1, at least one of (1) and
-        # (2) must apply.  Now |y| < 1/nbits(xc) iff |yc|*nbits(xc) <
-        # 10**-ye iff len(str(|yc|*nbits(xc)) <= -ye.
-        #
-        # There's also a limit to how large y can be, at least if it's
-        # positive: the normalized result will have coefficient xc**y,
-        # so if it's representable then xc**y < 10**p, and y <
-        # p/log10(xc).  Hence if y*log10(xc) >= p then the result is
-        # not exactly representable.
-
-        # if len(str(abs(yc*xe)) <= -ye then abs(yc*xe) < 10**-ye,
-        # so |y| < 1/xe and the result is not representable.
-        # Similarly, len(str(abs(yc)*xc_bits)) <= -ye implies |y|
-        # < 1/nbits(xc).
-
-        x = _WorkRep(self)
-        xc, xe = x.int, x.exp
-        while xc % 10 == 0:
-            xc //= 10
-            xe += 1
-
-        y = _WorkRep(other)
-        yc, ye = y.int, y.exp
-        while yc % 10 == 0:
-            yc //= 10
-            ye += 1
-
-        # case where xc == 1: result is 10**(xe*y), with xe*y
-        # required to be an integer
-        if xc == 1:
-            xe *= yc
-            # result is now 10**(xe * 10**ye);  xe * 10**ye must be integral
-            while xe % 10 == 0:
-                xe //= 10
-                ye += 1
-            if ye < 0:
-                return None
-            exponent = xe * 10**ye
-            if y.sign == 1:
-                exponent = -exponent
-            # if other is a nonnegative integer, use ideal exponent
-            if other._isinteger() and other._sign == 0:
-                ideal_exponent = self._exp*int(other)
-                zeros = min(exponent-ideal_exponent, p-1)
-            else:
-                zeros = 0
-            return _dec_from_triple(0, '1' + '0'*zeros, exponent-zeros)
-
-        # case where y is negative: xc must be either a power
-        # of 2 or a power of 5.
-        if y.sign == 1:
-            last_digit = xc % 10
-            if last_digit in (2,4,6,8):
-                # quick test for power of 2
-                if xc & -xc != xc:
-                    return None
-                # now xc is a power of 2; e is its exponent
-                e = _nbits(xc)-1
-
-                # We now have:
-                #
-                #   x = 2**e * 10**xe, e > 0, and y < 0.
-                #
-                # The exact result is:
-                #
-                #   x**y = 5**(-e*y) * 10**(e*y + xe*y)
-                #
-                # provided that both e*y and xe*y are integers.  Note that if
-                # 5**(-e*y) >= 10**p, then the result can't be expressed
-                # exactly with p digits of precision.
-                #
-                # Using the above, we can guard against large values of ye.
-                # 93/65 is an upper bound for log(10)/log(5), so if
-                #
-                #   ye >= len(str(93*p//65))
-                #
-                # then
-                #
-                #   -e*y >= -y >= 10**ye > 93*p/65 > p*log(10)/log(5),
-                #
-                # so 5**(-e*y) >= 10**p, and the coefficient of the result
-                # can't be expressed in p digits.
-
-                # emax >= largest e such that 5**e < 10**p.
-                emax = p*93//65
-                if ye >= len(str(emax)):
-                    return None
-
-                # Find -e*y and -xe*y; both must be integers
-                e = _decimal_lshift_exact(e * yc, ye)
-                xe = _decimal_lshift_exact(xe * yc, ye)
-                if e is None or xe is None:
-                    return None
-
-                if e > emax:
-                    return None
-                xc = 5**e
-
-            elif last_digit == 5:
-                # e >= log_5(xc) if xc is a power of 5; we have
-                # equality all the way up to xc=5**2658
-                e = _nbits(xc)*28//65
-                xc, remainder = divmod(5**e, xc)
-                if remainder:
-                    return None
-                while xc % 5 == 0:
-                    xc //= 5
-                    e -= 1
-
-                # Guard against large values of ye, using the same logic as in
-                # the 'xc is a power of 2' branch.  10/3 is an upper bound for
-                # log(10)/log(2).
-                emax = p*10//3
-                if ye >= len(str(emax)):
-                    return None
-
-                e = _decimal_lshift_exact(e * yc, ye)
-                xe = _decimal_lshift_exact(xe * yc, ye)
-                if e is None or xe is None:
-                    return None
-
-                if e > emax:
-                    return None
-                xc = 2**e
-            else:
-                return None
-
-            if xc >= 10**p:
-                return None
-            xe = -e-xe
-            return _dec_from_triple(0, str(xc), xe)
-
-        # now y is positive; find m and n such that y = m/n
-        if ye >= 0:
-            m, n = yc*10**ye, 1
-        else:
-            if xe != 0 and len(str(abs(yc*xe))) <= -ye:
-                return None
-            xc_bits = _nbits(xc)
-            if xc != 1 and len(str(abs(yc)*xc_bits)) <= -ye:
-                return None
-            m, n = yc, 10**(-ye)
-            while m % 2 == n % 2 == 0:
-                m //= 2
-                n //= 2
-            while m % 5 == n % 5 == 0:
-                m //= 5
-                n //= 5
-
-        # compute nth root of xc*10**xe
-        if n > 1:
-            # if 1 < xc < 2**n then xc isn't an nth power
-            if xc != 1 and xc_bits <= n:
-                return None
-
-            xe, rem = divmod(xe, n)
-            if rem != 0:
-                return None
-
-            # compute nth root of xc using Newton's method
-            a = 1 << -(-_nbits(xc)//n) # initial estimate
-            while True:
-                q, r = divmod(xc, a**(n-1))
-                if a <= q:
-                    break
-                else:
-                    a = (a*(n-1) + q)//n
-            if not (a == q and r == 0):
-                return None
-            xc = a
-
-        # now xc*10**xe is the nth root of the original xc*10**xe
-        # compute mth power of xc*10**xe
-
-        # if m > p*100//_log10_lb(xc) then m > p/log10(xc), hence xc**m >
-        # 10**p and the result is not representable.
-        if xc > 1 and m > p*100//_log10_lb(xc):
-            return None
-        xc = xc**m
-        xe *= m
-        if xc > 10**p:
-            return None
-
-        # by this point the result *is* exactly representable
-        # adjust the exponent to get as close as possible to the ideal
-        # exponent, if necessary
-        str_xc = str(xc)
-        if other._isinteger() and other._sign == 0:
-            ideal_exponent = self._exp*int(other)
-            zeros = min(xe-ideal_exponent, p-len(str_xc))
-        else:
-            zeros = 0
-        return _dec_from_triple(0, str_xc+'0'*zeros, xe-zeros)
-
-    def __pow__(self, other, modulo=None, context=None):
-        """Return self ** other [ % modulo].
-
-        With two arguments, compute self**other.
-
-        With three arguments, compute (self**other) % modulo.  For the
-        three argument form, the following restrictions on the
-        arguments hold:
-
-         - all three arguments must be integral
-         - other must be nonnegative
-         - either self or other (or both) must be nonzero
-         - modulo must be nonzero and must have at most p digits,
-           where p is the context precision.
-
-        If any of these restrictions is violated the InvalidOperation
-        flag is raised.
-
-        The result of pow(self, other, modulo) is identical to the
-        result that would be obtained by computing (self**other) %
-        modulo with unbounded precision, but is computed more
-        efficiently.  It is always exact.
-        """
-
-        if modulo is not None:
-            return self._power_modulo(other, modulo, context)
-
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-
-        if context is None:
-            context = getcontext()
-
-        # either argument is a NaN => result is NaN
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        # 0**0 = NaN (!), x**0 = 1 for nonzero x (including +/-Infinity)
-        if not other:
-            if not self:
-                return context._raise_error(InvalidOperation, '0 ** 0')
-            else:
-                return _One
-
-        # result has sign 1 iff self._sign is 1 and other is an odd integer
-        result_sign = 0
-        if self._sign == 1:
-            if other._isinteger():
-                if not other._iseven():
-                    result_sign = 1
-            else:
-                # -ve**noninteger = NaN
-                # (-0)**noninteger = 0**noninteger
-                if self:
-                    return context._raise_error(InvalidOperation,
-                        'x ** y with x negative and y not an integer')
-            # negate self, without doing any unwanted rounding
-            self = self.copy_negate()
-
-        # 0**(+ve or Inf)= 0; 0**(-ve or -Inf) = Infinity
-        if not self:
-            if other._sign == 0:
-                return _dec_from_triple(result_sign, '0', 0)
-            else:
-                return _SignedInfinity[result_sign]
-
-        # Inf**(+ve or Inf) = Inf; Inf**(-ve or -Inf) = 0
-        if self._isinfinity():
-            if other._sign == 0:
-                return _SignedInfinity[result_sign]
-            else:
-                return _dec_from_triple(result_sign, '0', 0)
-
-        # 1**other = 1, but the choice of exponent and the flags
-        # depend on the exponent of self, and on whether other is a
-        # positive integer, a negative integer, or neither
-        if self == _One:
-            if other._isinteger():
-                # exp = max(self._exp*max(int(other), 0),
-                # 1-context.prec) but evaluating int(other) directly
-                # is dangerous until we know other is small (other
-                # could be 1e999999999)
-                if other._sign == 1:
-                    multiplier = 0
-                elif other > context.prec:
-                    multiplier = context.prec
-                else:
-                    multiplier = int(other)
-
-                exp = self._exp * multiplier
-                if exp < 1-context.prec:
-                    exp = 1-context.prec
-                    context._raise_error(Rounded)
-            else:
-                context._raise_error(Inexact)
-                context._raise_error(Rounded)
-                exp = 1-context.prec
-
-            return _dec_from_triple(result_sign, '1'+'0'*-exp, exp)
-
-        # compute adjusted exponent of self
-        self_adj = self.adjusted()
-
-        # self ** infinity is infinity if self > 1, 0 if self < 1
-        # self ** -infinity is infinity if self < 1, 0 if self > 1
-        if other._isinfinity():
-            if (other._sign == 0) == (self_adj < 0):
-                return _dec_from_triple(result_sign, '0', 0)
-            else:
-                return _SignedInfinity[result_sign]
-
-        # from here on, the result always goes through the call
-        # to _fix at the end of this function.
-        ans = None
-        exact = False
-
-        # crude test to catch cases of extreme overflow/underflow.  If
-        # log10(self)*other >= 10**bound and bound >= len(str(Emax))
-        # then 10**bound >= 10**len(str(Emax)) >= Emax+1 and hence
-        # self**other >= 10**(Emax+1), so overflow occurs.  The test
-        # for underflow is similar.
-        bound = self._log10_exp_bound() + other.adjusted()
-        if (self_adj >= 0) == (other._sign == 0):
-            # self > 1 and other +ve, or self < 1 and other -ve
-            # possibility of overflow
-            if bound >= len(str(context.Emax)):
-                ans = _dec_from_triple(result_sign, '1', context.Emax+1)
-        else:
-            # self > 1 and other -ve, or self < 1 and other +ve
-            # possibility of underflow to 0
-            Etiny = context.Etiny()
-            if bound >= len(str(-Etiny)):
-                ans = _dec_from_triple(result_sign, '1', Etiny-1)
-
-        # try for an exact result with precision +1
-        if ans is None:
-            ans = self._power_exact(other, context.prec + 1)
-            if ans is not None:
-                if result_sign == 1:
-                    ans = _dec_from_triple(1, ans._int, ans._exp)
-                exact = True
-
-        # usual case: inexact result, x**y computed directly as exp(y*log(x))
-        if ans is None:
-            p = context.prec
-            x = _WorkRep(self)
-            xc, xe = x.int, x.exp
-            y = _WorkRep(other)
-            yc, ye = y.int, y.exp
-            if y.sign == 1:
-                yc = -yc
-
-            # compute correctly rounded result:  start with precision +3,
-            # then increase precision until result is unambiguously roundable
-            extra = 3
-            while True:
-                coeff, exp = _dpower(xc, xe, yc, ye, p+extra)
-                if coeff % (5*10**(len(str(coeff))-p-1)):
-                    break
-                extra += 3
-
-            ans = _dec_from_triple(result_sign, str(coeff), exp)
-
-        # unlike exp, ln and log10, the power function respects the
-        # rounding mode; no need to switch to ROUND_HALF_EVEN here
-
-        # There's a difficulty here when 'other' is not an integer and
-        # the result is exact.  In this case, the specification
-        # requires that the Inexact flag be raised (in spite of
-        # exactness), but since the result is exact _fix won't do this
-        # for us.  (Correspondingly, the Underflow signal should also
-        # be raised for subnormal results.)  We can't directly raise
-        # these signals either before or after calling _fix, since
-        # that would violate the precedence for signals.  So we wrap
-        # the ._fix call in a temporary context, and reraise
-        # afterwards.
-        if exact and not other._isinteger():
-            # pad with zeros up to length context.prec+1 if necessary; this
-            # ensures that the Rounded signal will be raised.
-            if len(ans._int) <= context.prec:
-                expdiff = context.prec + 1 - len(ans._int)
-                ans = _dec_from_triple(ans._sign, ans._int+'0'*expdiff,
-                                       ans._exp-expdiff)
-
-            # create a copy of the current context, with cleared flags/traps
-            newcontext = context.copy()
-            newcontext.clear_flags()
-            for exception in _signals:
-                newcontext.traps[exception] = 0
-
-            # round in the new context
-            ans = ans._fix(newcontext)
-
-            # raise Inexact, and if necessary, Underflow
-            newcontext._raise_error(Inexact)
-            if newcontext.flags[Subnormal]:
-                newcontext._raise_error(Underflow)
-
-            # propagate signals to the original context; _fix could
-            # have raised any of Overflow, Underflow, Subnormal,
-            # Inexact, Rounded, Clamped.  Overflow needs the correct
-            # arguments.  Note that the order of the exceptions is
-            # important here.
-            if newcontext.flags[Overflow]:
-                context._raise_error(Overflow, 'above Emax', ans._sign)
-            for exception in Underflow, Subnormal, Inexact, Rounded, Clamped:
-                if newcontext.flags[exception]:
-                    context._raise_error(exception)
-
-        else:
-            ans = ans._fix(context)
-
-        return ans
-
-    def __rpow__(self, other, context=None):
-        """Swaps self/other and returns __pow__."""
-        other = _convert_other(other)
-        if other is NotImplemented:
-            return other
-        return other.__pow__(self, context=context)
-
-    def normalize(self, context=None):
-        """Normalize- strip trailing 0s, change anything equal to 0 to 0e0"""
-
-        if context is None:
-            context = getcontext()
-
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-
-        dup = self._fix(context)
-        if dup._isinfinity():
-            return dup
-
-        if not dup:
-            return _dec_from_triple(dup._sign, '0', 0)
-        exp_max = [context.Emax, context.Etop()][context.clamp]
-        end = len(dup._int)
-        exp = dup._exp
-        while dup._int[end-1] == '0' and exp < exp_max:
-            exp += 1
-            end -= 1
-        return _dec_from_triple(dup._sign, dup._int[:end], exp)
-
-    def quantize(self, exp, rounding=None, context=None, watchexp=True):
-        """Quantize self so its exponent is the same as that of exp.
-
-        Similar to self._rescale(exp._exp) but with error checking.
-        """
-        exp = _convert_other(exp, raiseit=True)
-
-        if context is None:
-            context = getcontext()
-        if rounding is None:
-            rounding = context.rounding
-
-        if self._is_special or exp._is_special:
-            ans = self._check_nans(exp, context)
-            if ans:
-                return ans
-
-            if exp._isinfinity() or self._isinfinity():
-                if exp._isinfinity() and self._isinfinity():
-                    return Decimal(self)  # if both are inf, it is OK
-                return context._raise_error(InvalidOperation,
-                                        'quantize with one INF')
-
-        # if we're not watching exponents, do a simple rescale
-        if not watchexp:
-            ans = self._rescale(exp._exp, rounding)
-            # raise Inexact and Rounded where appropriate
-            if ans._exp > self._exp:
-                context._raise_error(Rounded)
-                if ans != self:
-                    context._raise_error(Inexact)
-            return ans
-
-        # exp._exp should be between Etiny and Emax
-        if not (context.Etiny() <= exp._exp <= context.Emax):
-            return context._raise_error(InvalidOperation,
-                   'target exponent out of bounds in quantize')
-
-        if not self:
-            ans = _dec_from_triple(self._sign, '0', exp._exp)
-            return ans._fix(context)
-
-        self_adjusted = self.adjusted()
-        if self_adjusted > context.Emax:
-            return context._raise_error(InvalidOperation,
-                                        'exponent of quantize result too large for current context')
-        if self_adjusted - exp._exp + 1 > context.prec:
-            return context._raise_error(InvalidOperation,
-                                        'quantize result has too many digits for current context')
-
-        ans = self._rescale(exp._exp, rounding)
-        if ans.adjusted() > context.Emax:
-            return context._raise_error(InvalidOperation,
-                                        'exponent of quantize result too large for current context')
-        if len(ans._int) > context.prec:
-            return context._raise_error(InvalidOperation,
-                                        'quantize result has too many digits for current context')
-
-        # raise appropriate flags
-        if ans and ans.adjusted() < context.Emin:
-            context._raise_error(Subnormal)
-        if ans._exp > self._exp:
-            if ans != self:
-                context._raise_error(Inexact)
-            context._raise_error(Rounded)
-
-        # call to fix takes care of any necessary folddown, and
-        # signals Clamped if necessary
-        ans = ans._fix(context)
-        return ans
-
-    def same_quantum(self, other, context=None):
-        """Return True if self and other have the same exponent; otherwise
-        return False.
-
-        If either operand is a special value, the following rules are used:
-           * return True if both operands are infinities
-           * return True if both operands are NaNs
-           * otherwise, return False.
-        """
-        other = _convert_other(other, raiseit=True)
-        if self._is_special or other._is_special:
-            return (self.is_nan() and other.is_nan() or
-                    self.is_infinite() and other.is_infinite())
-        return self._exp == other._exp
-
-    def _rescale(self, exp, rounding):
-        """Rescale self so that the exponent is exp, either by padding with zeros
-        or by truncating digits, using the given rounding mode.
-
-        Specials are returned without change.  This operation is
-        quiet: it raises no flags, and uses no information from the
-        context.
-
-        exp = exp to scale to (an integer)
-        rounding = rounding mode
-        """
-        if self._is_special:
-            return Decimal(self)
-        if not self:
-            return _dec_from_triple(self._sign, '0', exp)
-
-        if self._exp >= exp:
-            # pad answer with zeros if necessary
-            return _dec_from_triple(self._sign,
-                                        self._int + '0'*(self._exp - exp), exp)
-
-        # too many digits; round and lose data.  If self.adjusted() <
-        # exp-1, replace self by 10**(exp-1) before rounding
-        digits = len(self._int) + self._exp - exp
-        if digits < 0:
-            self = _dec_from_triple(self._sign, '1', exp-1)
-            digits = 0
-        this_function = self._pick_rounding_function[rounding]
-        changed = this_function(self, digits)
-        coeff = self._int[:digits] or '0'
-        if changed == 1:
-            coeff = str(int(coeff)+1)
-        return _dec_from_triple(self._sign, coeff, exp)
-
-    def _round(self, places, rounding):
-        """Round a nonzero, nonspecial Decimal to a fixed number of
-        significant figures, using the given rounding mode.
-
-        Infinities, NaNs and zeros are returned unaltered.
-
-        This operation is quiet: it raises no flags, and uses no
-        information from the context.
-
-        """
-        if places <= 0:
-            raise ValueError("argument should be at least 1 in _round")
-        if self._is_special or not self:
-            return Decimal(self)
-        ans = self._rescale(self.adjusted()+1-places, rounding)
-        # it can happen that the rescale alters the adjusted exponent;
-        # for example when rounding 99.97 to 3 significant figures.
-        # When this happens we end up with an extra 0 at the end of
-        # the number; a second rescale fixes this.
-        if ans.adjusted() != self.adjusted():
-            ans = ans._rescale(ans.adjusted()+1-places, rounding)
-        return ans
-
-    def to_integral_exact(self, rounding=None, context=None):
-        """Rounds to a nearby integer.
-
-        If no rounding mode is specified, take the rounding mode from
-        the context.  This method raises the Rounded and Inexact flags
-        when appropriate.
-
-        See also: to_integral_value, which does exactly the same as
-        this method except that it doesn't raise Inexact or Rounded.
-        """
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-            return Decimal(self)
-        if self._exp >= 0:
-            return Decimal(self)
-        if not self:
-            return _dec_from_triple(self._sign, '0', 0)
-        if context is None:
-            context = getcontext()
-        if rounding is None:
-            rounding = context.rounding
-        ans = self._rescale(0, rounding)
-        if ans != self:
-            context._raise_error(Inexact)
-        context._raise_error(Rounded)
-        return ans
-
-    def to_integral_value(self, rounding=None, context=None):
-        """Rounds to the nearest integer, without raising inexact, rounded."""
-        if context is None:
-            context = getcontext()
-        if rounding is None:
-            rounding = context.rounding
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-            return Decimal(self)
-        if self._exp >= 0:
-            return Decimal(self)
-        else:
-            return self._rescale(0, rounding)
-
-    # the method name changed, but we provide also the old one, for compatibility
-    to_integral = to_integral_value
-
-    def sqrt(self, context=None):
-        """Return the square root of self."""
-        if context is None:
-            context = getcontext()
-
-        if self._is_special:
-            ans = self._check_nans(context=context)
-            if ans:
-                return ans
-
-            if self._isinfinity() and self._sign == 0:
-                return Decimal(self)
-
-        if not self:
-            # exponent = self._exp // 2.  sqrt(-0) = -0
-            ans = _dec_from_triple(self._sign, '0', self._exp // 2)
-            return ans._fix(context)
-
-        if self._sign == 1:
-            return context._raise_error(InvalidOperation, 'sqrt(-x), x > 0')
-
-        # At this point self represents a positive number.  Let p be
-        # the desired precision and express self in the form c*100**e
-        # with c a positive real number and e an integer, c and e
-        # being chosen so that 100**(p-1) <= c < 100**p.  Then the
-        # (exact) square root of self is sqrt(c)*10**e, and 10**(p-1)
-        # <= sqrt(c) < 10**p, so the closest representable Decimal at
-        # precision p is n*10**e where n = round_half_even(sqrt(c)),
-        # the closest integer to sqrt(c) with the even integer chosen
-        # in the case of a tie.
-        #
-        # To ensure correct rounding in all cases, we use the
-        # following trick: we compute the square root to an extra
-        # place (precision p+1 instead of precision p), rounding down.
-        # Then, if the result is inexact and its last digit is 0 or 5,
-        # we increase the last digit to 1 or 6 respectively; if it's
-        # exact we leave the last digit alone.  Now the final round to
-        # p places (or fewer in the case of underflow) will round
-        # correctly and raise the appropriate flags.
-
-        # use an extra digit of precision
-        prec = context.prec+1
-
-        # write argument in the form c*100**e where e = self._exp//2
-        # is the 'ideal' exponent, to be used if the square root is
-        # exactly representable.  l is the number of 'digits' of c in
-        # base 100, so that 100**(l-1) <= c < 100**l.
-        op = _WorkRep(self)
-        e = op.exp >> 1
-        if op.exp & 1:
-            c = op.int * 10
-            l = (len(self._int) >> 1) + 1
-        else:
-            c = op.int
-            l = len(self._int)+1 >> 1
-
-        # rescale so that c has exactly prec base 100 'digits'
-        shift = prec-l
-        if shift >= 0:
-            c *= 100**shift
-            exact = True
-        else:
-            c, remainder = divmod(c, 100**-shift)
-            exact = not remainder
-        e -= shift
-
-        # find n = floor(sqrt(c)) using Newton's method
-        n = 10**prec
-        while True:
-            q = c//n
-            if n <= q:
-                break
-            else:
-                n = n + q >> 1
-        exact = exact and n*n == c
-
-        if exact:
-            # result is exact; rescale to use ideal exponent e
-            if shift >= 0:
-                # assert n % 10**shift == 0
-                n //= 10**shift
-            else:
-                n *= 10**-shift
-            e += shift
-        else:
-            # result is not exact; fix last digit as described above
-            if n % 5 == 0:
-                n += 1
-
-        ans = _dec_from_triple(0, str(n), e)
-
-        # round, and fit to current context
-        context = context._shallow_copy()
-        rounding = context._set_rounding(ROUND_HALF_EVEN)
-        ans = ans._fix(context)
-        context.rounding = rounding
-
-        return ans
-
-    def max(self, other, context=None):
-        """Returns the larger value.
-
-        Like max(self, other) except if one is not a number, returns
-        NaN (and signals if one is sNaN).  Also rounds.
-        """
-        other = _convert_other(other, raiseit=True)
-
-        if context is None:
-            context = getcontext()
-
-        if self._is_special or other._is_special:
-            # If one operand is a quiet NaN and the other is number, then the
-            # number is always returned
-            sn = self._isnan()
-            on = other._isnan()
-            if sn or on:
-                if on == 1 and sn == 0:
-                    return self._fix(context)
-                if sn == 1 and on == 0:
-                    return other._fix(context)
-                return self._check_nans(other, context)
-
-        c = self._cmp(other)
-        if c == 0:
-            # If both operands are finite and equal in numerical value
-            # then an ordering is applied:
-            #
-            # If the signs differ then max returns the operand with the
-            # positive sign and min returns the operand with the negative sign
-            #
-            # If the signs are the same then the exponent is used to select
-            # the result.  This is exactly the ordering used in compare_total.
-            c = self.compare_total(other)
-
-        if c == -1:
-            ans = other
-        else:
-            ans = self
-
-        return ans._fix(context)
-
-    def min(self, other, context=None):
-        """Returns the smaller value.
-
-        Like min(self, other) except if one is not a number, returns
-        NaN (and signals if one is sNaN).  Also rounds.
-        """
-        other = _convert_other(other, raiseit=True)
-
-        if context is None:
-            context = getcontext()
-
-        if self._is_special or other._is_special:
-            # If one operand is a quiet NaN and the other is number, then the
-            # number is always returned
-            sn = self._isnan()
-            on = other._isnan()
-            if sn or on:
-                if on == 1 and sn == 0:
-                    return self._fix(context)
-                if sn == 1 and on == 0:
-                    return other._fix(context)
-                return self._check_nans(other, context)
-
-        c = self._cmp(other)
-        if c == 0:
-            c = self.compare_total(other)
-
-        if c == -1:
-            ans = self
-        else:
-            ans = other
-
-        return ans._fix(context)
-
-    def _isinteger(self):
-        """Returns whether self is an integer"""
-        if self._is_special:
-            return False
-        if self._exp >= 0:
-            return True
-        rest = self._int[self._exp:]
-        return rest == '0'*len(rest)
-
-    def _iseven(self):
-        """Returns True if self is even.  Assumes self is an integer."""
-        if not self or self._exp > 0:
-            return True
-        return self._int[-1+self._exp] in '02468'
-
-    def adjusted(self):
-        """Return the adjusted exponent of self"""
-        try:
-            return self._exp + len(self._int) - 1
-        # If NaN or Infinity, self._exp is string
-        except TypeError:
-            return 0
-
-    def canonical(self):
-        """Returns the same Decimal object.
-
-        As we do not have different encodings for the same number, the
-        received object already is in its canonical form.
-        """
-        return self
-
-    def compare_signal(self, other, context=None):
-        """Compares self to the other operand numerically.
-
-        It's pretty much like compare(), but all NaNs signal, with signaling
-        NaNs taking precedence over quiet NaNs.
-        """
-        other = _convert_other(other, raiseit = True)
-        ans = self._compare_check_nans(other, context)
-        if ans:
-            return ans
-        return self.compare(other, context=context)
-
-    def compare_total(self, other, context=None):
-        """Compares self to other using the abstract representations.
-
-        This is not like the standard compare, which use their numerical
-        value. Note that a total ordering is defined for all possible abstract
-        representations.
-        """
-        other = _convert_other(other, raiseit=True)
-
-        # if one is negative and the other is positive, it's easy
-        if self._sign and not other._sign:
-            return _NegativeOne
-        if not self._sign and other._sign:
-            return _One
-        sign = self._sign
-
-        # let's handle both NaN types
-        self_nan = self._isnan()
-        other_nan = other._isnan()
-        if self_nan or other_nan:
-            if self_nan == other_nan:
-                # compare payloads as though they're integers
-                self_key = len(self._int), self._int
-                other_key = len(other._int), other._int
-                if self_key < other_key:
-                    if sign:
-                        return _One
-                    else:
-                        return _NegativeOne
-                if self_key > other_key:
-                    if sign:
-                        return _NegativeOne
-                    else:
-                        return _One
-                return _Zero
-
-            if sign:
-                if self_nan == 1:
-                    return _NegativeOne
-                if other_nan == 1:
-                    return _One
-                if self_nan == 2:
-                    return _NegativeOne
-                if other_nan == 2:
-                    return _One
-            else:
-                if self_nan == 1:
-                    return _One
-                if other_nan == 1:
-                    return _NegativeOne
-                if self_nan == 2:
-                    return _One
-                if other_nan == 2:
-                    return _NegativeOne
-
-        if self < other:
-            return _NegativeOne
-        if self > other:
-            return _One
-
-        if self._exp < other._exp:
-            if sign:
-                return _One
-            else:
-                return _NegativeOne
-        if self._exp > other._exp:
-            if sign:
-                return _NegativeOne
-            else:
-                return _One
-        return _Zero
-
-
-    def compare_total_mag(self, other, context=None):
-        """Compares self to other using abstract repr., ignoring sign.
-
-        Like compare_total, but with operand's sign ignored and assumed to be 0.
-        """
-        other = _convert_other(other, raiseit=True)
-
-        s = self.copy_abs()
-        o = other.copy_abs()
-        return s.compare_total(o)
-
-    def copy_abs(self):
-        """Returns a copy with the sign set to 0. """
-        return _dec_from_triple(0, self._int, self._exp, self._is_special)
-
-    def copy_negate(self):
-        """Returns a copy with the sign inverted."""
-        if self._sign:
-            return _dec_from_triple(0, self._int, self._exp, self._is_special)
-        else:
-            return _dec_from_triple(1, self._int, self._exp, self._is_special)
-
-    def copy_sign(self, other, context=None):
-        """Returns self with the sign of other."""
-        other = _convert_other(other, raiseit=True)
-        return _dec_from_triple(other._sign, self._int,
-                                self._exp, self._is_special)
-
-    def exp(self, context=None):
-        """Returns e ** self."""
-
-        if context is None:
-            context = getcontext()
-
-        # exp(NaN) = NaN
-        ans = self._check_nans(context=context)
-        if ans:
-            return ans
-
-        # exp(-Infinity) = 0
-        if self._isinfinity() == -1:
-            return _Zero
-
-        # exp(0) = 1
-        if not self:
-            return _One
-
-        # exp(Infinity) = Infinity
-        if self._isinfinity() == 1:
-            return Decimal(self)
-
-        # the result is now guaranteed to be inexact (the true
-        # mathematical result is transcendental). There's no need to
-        # raise Rounded and Inexact here---they'll always be raised as
-        # a result of the call to _fix.
-        p = context.prec
-        adj = self.adjusted()
-
-        # we only need to do any computation for quite a small range
-        # of adjusted exponents---for example, -29 <= adj <= 10 for
-        # the default context.  For smaller exponent the result is
-        # indistinguishable from 1 at the given precision, while for
-        # larger exponent the result either overflows or underflows.
-        if self._sign == 0 and adj > len(str((context.Emax+1)*3)):
-            # overflow
-            ans = _dec_from_triple(0, '1', context.Emax+1)
-        elif self._sign == 1 and adj > len(str((-context.Etiny()+1)*3)):
-            # underflow to 0
-            ans = _dec_from_triple(0, '1', context.Etiny()-1)
-        elif self._sign == 0 and adj < -p:
-            # p+1 digits; final round will raise correct flags
-            ans = _dec_from_triple(0, '1' + '0'*(p-1) + '1', -p)
-        elif self._sign == 1 and adj < -p-1:
-            # p+1 digits; final round will raise correct flags
-            ans = _dec_from_triple(0, '9'*(p+1), -p-1)
-        # general case
-        else:
-            op = _WorkRep(self)
-            c, e = op.int, op.exp
-            if op.sign == 1:
-                c = -c
-
-            # compute correctly rounded result: increase precision by
-            # 3 digits at a time until we get an unambiguously
-            # roundable result
-            extra = 3
-            while True:
-                coeff, exp = _dexp(c, e, p+extra)
-                if coeff % (5*10**(len(str(coeff))-p-1)):
-                    break
-                extra += 3
-
-            ans = _dec_from_triple(0, str(coeff), exp)
-
-        # at this stage, ans should round correctly with *any*
-        # rounding mode, not just with ROUND_HALF_EVEN
-        context = context._shallow_copy()
-        rounding = context._set_rounding(ROUND_HALF_EVEN)
-        ans = ans._fix(context)
-        context.rounding = rounding
-
-        return ans
-
-    def is_canonical(self):
-        """Return True if self is canonical; otherwise return False.
-
-        Currently, the encoding of a Decimal instance is always
-        canonical, so this method returns True for any Decimal.
-        """
-        return True
-
-    def is_finite(self):
-        """Return True if self is finite; otherwise return False.
-
-        A Decimal instance is considered finite if it is neither
-        infinite nor a NaN.
-        """
-        return not self._is_special
-
-    def is_infinite(self):
-        """Return True if self is infinite; otherwise return False."""
-        return self._exp == 'F'
-
-    def is_nan(self):
-        """Return True if self is a qNaN or sNaN; otherwise return False."""
-        return self._exp in ('n', 'N')
-
-    def is_normal(self, context=None):
-        """Return True if self is a normal number; otherwise return False."""
-        if self._is_special or not self:
-            return False
-        if context is None:
-            context = getcontext()
-        return context.Emin <= self.adjusted()
-
-    def is_qnan(self):
-        """Return True if self is a quiet NaN; otherwise return False."""
-        return self._exp == 'n'
-
-    def is_signed(self):
-        """Return True if self is negative; otherwise return False."""
-        return self._sign == 1
-
-    def is_snan(self):
-        """Return True if self is a signaling NaN; otherwise return False."""
-        return self._exp == 'N'
-
-    def is_subnormal(self, context=None):
-        """Return True if self is subnormal; otherwise return False."""
-        if self._is_special or not self:
-            return False
-        if context is None:
-            context = getcontext()
-        return self.adjusted() < context.Emin
-
-    def is_zero(self):
-        """Return True if self is a zero; otherwise return False."""
-        return not self._is_special and self._int == '0'
-
-    def _ln_exp_bound(self):
-        """Compute a lower bound for the adjusted exponent of self.ln().
-        In other words, compute r such that self.ln() >= 10**r.  Assumes
-        that self is finite and positive and that self != 1.
-        """
-
-        # for 0.1 <= x <= 10 we use the inequalities 1-1/x <= ln(x) <= x-1
-        adj = self._exp + len(self._int) - 1
-        if adj >= 1:
-            # argument >= 10; we use 23/10 = 2.3 as a lower bound for ln(10)
-            return len(str(adj*23//10)) - 1
-        if adj <= -2:
-            # argument <= 0.1
-            return len(str((-1-adj)*23//10)) - 1
-        op = _WorkRep(self)
-        c, e = op.int, op.exp
-        if adj == 0:
-            # 1 < self < 10
-            num = str(c-10**-e)
-            den = str(c)
-            return len(num) - len(den) - (num < den)
-        # adj == -1, 0.1 <= self < 1
-        return e + len(str(10**-e - c)) - 1
-
-
-    def ln(self, context=None):
-        """Returns the natural (base e) logarithm of self."""
-
-        if context is None:
-            context = getcontext()
-
-        # ln(NaN) = NaN
-        ans = self._check_nans(context=context)
-        if ans:
-            return ans
-
-        # ln(0.0) == -Infinity
-        if not self:
-            return _NegativeInfinity
-
-        # ln(Infinity) = Infinity
-        if self._isinfinity() == 1:
-            return _Infinity
-
-        # ln(1.0) == 0.0
-        if self == _One:
-            return _Zero
-
-        # ln(negative) raises InvalidOperation
-        if self._sign == 1:
-            return context._raise_error(InvalidOperation,
-                                        'ln of a negative value')
-
-        # result is irrational, so necessarily inexact
-        op = _WorkRep(self)
-        c, e = op.int, op.exp
-        p = context.prec
-
-        # correctly rounded result: repeatedly increase precision by 3
-        # until we get an unambiguously roundable result
-        places = p - self._ln_exp_bound() + 2 # at least p+3 places
-        while True:
-            coeff = _dlog(c, e, places)
-            # assert len(str(abs(coeff)))-p >= 1
-            if coeff % (5*10**(len(str(abs(coeff)))-p-1)):
-                break
-            places += 3
-        ans = _dec_from_triple(int(coeff<0), str(abs(coeff)), -places)
-
-        context = context._shallow_copy()
-        rounding = context._set_rounding(ROUND_HALF_EVEN)
-        ans = ans._fix(context)
-        context.rounding = rounding
-        return ans
-
-    def _log10_exp_bound(self):
-        """Compute a lower bound for the adjusted exponent of self.log10().
-        In other words, find r such that self.log10() >= 10**r.
-        Assumes that self is finite and positive and that self != 1.
-        """
-
-        # For x >= 10 or x < 0.1 we only need a bound on the integer
-        # part of log10(self), and this comes directly from the
-        # exponent of x.  For 0.1 <= x <= 10 we use the inequalities
-        # 1-1/x <= log(x) <= x-1. If x > 1 we have |log10(x)| >
-        # (1-1/x)/2.31 > 0.  If x < 1 then |log10(x)| > (1-x)/2.31 > 0
-
-        adj = self._exp + len(self._int) - 1
-        if adj >= 1:
-            # self >= 10
-            return len(str(adj))-1
-        if adj <= -2:
-            # self < 0.1
-            return len(str(-1-adj))-1
-        op = _WorkRep(self)
-        c, e = op.int, op.exp
-        if adj == 0:
-            # 1 < self < 10
-            num = str(c-10**-e)
-            den = str(231*c)
-            return len(num) - len(den) - (num < den) + 2
-        # adj == -1, 0.1 <= self < 1
-        num = str(10**-e-c)
-        return len(num) + e - (num < "231") - 1
-
-    def log10(self, context=None):
-        """Returns the base 10 logarithm of self."""
-
-        if context is None:
-            context = getcontext()
-
-        # log10(NaN) = NaN
-        ans = self._check_nans(context=context)
-        if ans:
-            return ans
-
-        # log10(0.0) == -Infinity
-        if not self:
-            return _NegativeInfinity
-
-        # log10(Infinity) = Infinity
-        if self._isinfinity() == 1:
-            return _Infinity
-
-        # log10(negative or -Infinity) raises InvalidOperation
-        if self._sign == 1:
-            return context._raise_error(InvalidOperation,
-                                        'log10 of a negative value')
-
-        # log10(10**n) = n
-        if self._int[0] == '1' and self._int[1:] == '0'*(len(self._int) - 1):
-            # answer may need rounding
-            ans = Decimal(self._exp + len(self._int) - 1)
-        else:
-            # result is irrational, so necessarily inexact
-            op = _WorkRep(self)
-            c, e = op.int, op.exp
-            p = context.prec
-
-            # correctly rounded result: repeatedly increase precision
-            # until result is unambiguously roundable
-            places = p-self._log10_exp_bound()+2
-            while True:
-                coeff = _dlog10(c, e, places)
-                # assert len(str(abs(coeff)))-p >= 1
-                if coeff % (5*10**(len(str(abs(coeff)))-p-1)):
-                    break
-                places += 3
-            ans = _dec_from_triple(int(coeff<0), str(abs(coeff)), -places)
-
-        context = context._shallow_copy()
-        rounding = context._set_rounding(ROUND_HALF_EVEN)
-        ans = ans._fix(context)
-        context.rounding = rounding
-        return ans
-
-    def logb(self, context=None):
-        """ Returns the exponent of the magnitude of self's MSD.
-
-        The result is the integer which is the exponent of the magnitude
-        of the most significant digit of self (as though it were truncated
-        to a single digit while maintaining the value of that digit and
-        without limiting the resulting exponent).
-        """
-        # logb(NaN) = NaN
-        ans = self._check_nans(context=context)
-        if ans:
-            return ans
-
-        if context is None:
-            context = getcontext()
-
-        # logb(+/-Inf) = +Inf
-        if self._isinfinity():
-            return _Infinity
-
-        # logb(0) = -Inf, DivisionByZero
-        if not self:
-            return context._raise_error(DivisionByZero, 'logb(0)', 1)
-
-        # otherwise, simply return the adjusted exponent of self, as a
-        # Decimal.  Note that no attempt is made to fit the result
-        # into the current context.
-        ans = Decimal(self.adjusted())
-        return ans._fix(context)
-
-    def _islogical(self):
-        """Return True if self is a logical operand.
-
-        For being logical, it must be a finite number with a sign of 0,
-        an exponent of 0, and a coefficient whose digits must all be
-        either 0 or 1.
-        """
-        if self._sign != 0 or self._exp != 0:
-            return False
-        for dig in self._int:
-            if dig not in '01':
-                return False
-        return True
-
-    def _fill_logical(self, context, opa, opb):
-        dif = context.prec - len(opa)
-        if dif > 0:
-            opa = '0'*dif + opa
-        elif dif < 0:
-            opa = opa[-context.prec:]
-        dif = context.prec - len(opb)
-        if dif > 0:
-            opb = '0'*dif + opb
-        elif dif < 0:
-            opb = opb[-context.prec:]
-        return opa, opb
-
-    def logical_and(self, other, context=None):
-        """Applies an 'and' operation between self and other's digits."""
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        if not self._islogical() or not other._islogical():
-            return context._raise_error(InvalidOperation)
-
-        # fill to context.prec
-        (opa, opb) = self._fill_logical(context, self._int, other._int)
-
-        # make the operation, and clean starting zeroes
-        result = "".join([str(int(a)&int(b)) for a,b in zip(opa,opb)])
-        return _dec_from_triple(0, result.lstrip('0') or '0', 0)
-
-    def logical_invert(self, context=None):
-        """Invert all its digits."""
-        if context is None:
-            context = getcontext()
-        return self.logical_xor(_dec_from_triple(0,'1'*context.prec,0),
-                                context)
-
-    def logical_or(self, other, context=None):
-        """Applies an 'or' operation between self and other's digits."""
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        if not self._islogical() or not other._islogical():
-            return context._raise_error(InvalidOperation)
-
-        # fill to context.prec
-        (opa, opb) = self._fill_logical(context, self._int, other._int)
-
-        # make the operation, and clean starting zeroes
-        result = "".join([str(int(a)|int(b)) for a,b in zip(opa,opb)])
-        return _dec_from_triple(0, result.lstrip('0') or '0', 0)
-
-    def logical_xor(self, other, context=None):
-        """Applies an 'xor' operation between self and other's digits."""
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        if not self._islogical() or not other._islogical():
-            return context._raise_error(InvalidOperation)
-
-        # fill to context.prec
-        (opa, opb) = self._fill_logical(context, self._int, other._int)
-
-        # make the operation, and clean starting zeroes
-        result = "".join([str(int(a)^int(b)) for a,b in zip(opa,opb)])
-        return _dec_from_triple(0, result.lstrip('0') or '0', 0)
-
-    def max_mag(self, other, context=None):
-        """Compares the values numerically with their sign ignored."""
-        other = _convert_other(other, raiseit=True)
-
-        if context is None:
-            context = getcontext()
-
-        if self._is_special or other._is_special:
-            # If one operand is a quiet NaN and the other is number, then the
-            # number is always returned
-            sn = self._isnan()
-            on = other._isnan()
-            if sn or on:
-                if on == 1 and sn == 0:
-                    return self._fix(context)
-                if sn == 1 and on == 0:
-                    return other._fix(context)
-                return self._check_nans(other, context)
-
-        c = self.copy_abs()._cmp(other.copy_abs())
-        if c == 0:
-            c = self.compare_total(other)
-
-        if c == -1:
-            ans = other
-        else:
-            ans = self
-
-        return ans._fix(context)
-
-    def min_mag(self, other, context=None):
-        """Compares the values numerically with their sign ignored."""
-        other = _convert_other(other, raiseit=True)
-
-        if context is None:
-            context = getcontext()
-
-        if self._is_special or other._is_special:
-            # If one operand is a quiet NaN and the other is number, then the
-            # number is always returned
-            sn = self._isnan()
-            on = other._isnan()
-            if sn or on:
-                if on == 1 and sn == 0:
-                    return self._fix(context)
-                if sn == 1 and on == 0:
-                    return other._fix(context)
-                return self._check_nans(other, context)
-
-        c = self.copy_abs()._cmp(other.copy_abs())
-        if c == 0:
-            c = self.compare_total(other)
-
-        if c == -1:
-            ans = self
-        else:
-            ans = other
-
-        return ans._fix(context)
-
-    def next_minus(self, context=None):
-        """Returns the largest representable number smaller than itself."""
-        if context is None:
-            context = getcontext()
-
-        ans = self._check_nans(context=context)
-        if ans:
-            return ans
-
-        if self._isinfinity() == -1:
-            return _NegativeInfinity
-        if self._isinfinity() == 1:
-            return _dec_from_triple(0, '9'*context.prec, context.Etop())
-
-        context = context.copy()
-        context._set_rounding(ROUND_FLOOR)
-        context._ignore_all_flags()
-        new_self = self._fix(context)
-        if new_self != self:
-            return new_self
-        return self.__sub__(_dec_from_triple(0, '1', context.Etiny()-1),
-                            context)
-
-    def next_plus(self, context=None):
-        """Returns the smallest representable number larger than itself."""
-        if context is None:
-            context = getcontext()
-
-        ans = self._check_nans(context=context)
-        if ans:
-            return ans
-
-        if self._isinfinity() == 1:
-            return _Infinity
-        if self._isinfinity() == -1:
-            return _dec_from_triple(1, '9'*context.prec, context.Etop())
-
-        context = context.copy()
-        context._set_rounding(ROUND_CEILING)
-        context._ignore_all_flags()
-        new_self = self._fix(context)
-        if new_self != self:
-            return new_self
-        return self.__add__(_dec_from_triple(0, '1', context.Etiny()-1),
-                            context)
-
-    def next_toward(self, other, context=None):
-        """Returns the number closest to self, in the direction towards other.
-
-        The result is the closest representable number to self
-        (excluding self) that is in the direction towards other,
-        unless both have the same value.  If the two operands are
-        numerically equal, then the result is a copy of self with the
-        sign set to be the same as the sign of other.
-        """
-        other = _convert_other(other, raiseit=True)
-
-        if context is None:
-            context = getcontext()
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        comparison = self._cmp(other)
-        if comparison == 0:
-            return self.copy_sign(other)
-
-        if comparison == -1:
-            ans = self.next_plus(context)
-        else: # comparison == 1
-            ans = self.next_minus(context)
-
-        # decide which flags to raise using value of ans
-        if ans._isinfinity():
-            context._raise_error(Overflow,
-                                 'Infinite result from next_toward',
-                                 ans._sign)
-            context._raise_error(Inexact)
-            context._raise_error(Rounded)
-        elif ans.adjusted() < context.Emin:
-            context._raise_error(Underflow)
-            context._raise_error(Subnormal)
-            context._raise_error(Inexact)
-            context._raise_error(Rounded)
-            # if precision == 1 then we don't raise Clamped for a
-            # result 0E-Etiny.
-            if not ans:
-                context._raise_error(Clamped)
-
-        return ans
-
-    def number_class(self, context=None):
-        """Returns an indication of the class of self.
-
-        The class is one of the following strings:
-          sNaN
-          NaN
-          -Infinity
-          -Normal
-          -Subnormal
-          -Zero
-          +Zero
-          +Subnormal
-          +Normal
-          +Infinity
-        """
-        if self.is_snan():
-            return "sNaN"
-        if self.is_qnan():
-            return "NaN"
-        inf = self._isinfinity()
-        if inf == 1:
-            return "+Infinity"
-        if inf == -1:
-            return "-Infinity"
-        if self.is_zero():
-            if self._sign:
-                return "-Zero"
-            else:
-                return "+Zero"
-        if context is None:
-            context = getcontext()
-        if self.is_subnormal(context=context):
-            if self._sign:
-                return "-Subnormal"
-            else:
-                return "+Subnormal"
-        # just a normal, regular, boring number, :)
-        if self._sign:
-            return "-Normal"
-        else:
-            return "+Normal"
-
-    def radix(self):
-        """Just returns 10, as this is Decimal, :)"""
-        return Decimal(10)
-
-    def rotate(self, other, context=None):
-        """Returns a rotated copy of self, value-of-other times."""
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        if other._exp != 0:
-            return context._raise_error(InvalidOperation)
-        if not (-context.prec <= int(other) <= context.prec):
-            return context._raise_error(InvalidOperation)
-
-        if self._isinfinity():
-            return Decimal(self)
-
-        # get values, pad if necessary
-        torot = int(other)
-        rotdig = self._int
-        topad = context.prec - len(rotdig)
-        if topad > 0:
-            rotdig = '0'*topad + rotdig
-        elif topad < 0:
-            rotdig = rotdig[-topad:]
-
-        # let's rotate!
-        rotated = rotdig[torot:] + rotdig[:torot]
-        return _dec_from_triple(self._sign,
-                                rotated.lstrip('0') or '0', self._exp)
-
-    def scaleb(self, other, context=None):
-        """Returns self operand after adding the second value to its exp."""
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        if other._exp != 0:
-            return context._raise_error(InvalidOperation)
-        liminf = -2 * (context.Emax + context.prec)
-        limsup =  2 * (context.Emax + context.prec)
-        if not (liminf <= int(other) <= limsup):
-            return context._raise_error(InvalidOperation)
-
-        if self._isinfinity():
-            return Decimal(self)
-
-        d = _dec_from_triple(self._sign, self._int, self._exp + int(other))
-        d = d._fix(context)
-        return d
-
-    def shift(self, other, context=None):
-        """Returns a shifted copy of self, value-of-other times."""
-        if context is None:
-            context = getcontext()
-
-        other = _convert_other(other, raiseit=True)
-
-        ans = self._check_nans(other, context)
-        if ans:
-            return ans
-
-        if other._exp != 0:
-            return context._raise_error(InvalidOperation)
-        if not (-context.prec <= int(other) <= context.prec):
-            return context._raise_error(InvalidOperation)
-
-        if self._isinfinity():
-            return Decimal(self)
-
-        # get values, pad if necessary
-        torot = int(other)
-        rotdig = self._int
-        topad = context.prec - len(rotdig)
-        if topad > 0:
-            rotdig = '0'*topad + rotdig
-        elif topad < 0:
-            rotdig = rotdig[-topad:]
-
-        # let's shift!
-        if torot < 0:
-            shifted = rotdig[:torot]
-        else:
-            shifted = rotdig + '0'*torot
-            shifted = shifted[-context.prec:]
-
-        return _dec_from_triple(self._sign,
-                                    shifted.lstrip('0') or '0', self._exp)
-
-    # Support for pickling, copy, and deepcopy
-    def __reduce__(self):
-        return (self.__class__, (str(self),))
-
-    def __copy__(self):
-        if type(self) is Decimal:
-            return self     # I'm immutable; therefore I am my own clone
-        return self.__class__(str(self))
-
-    def __deepcopy__(self, memo):
-        if type(self) is Decimal:
-            return self     # My components are also immutable
-        return self.__class__(str(self))
-
-    # PEP 3101 support.  the _localeconv keyword argument should be
-    # considered private: it's provided for ease of testing only.
-    def __format__(self, specifier, context=None, _localeconv=None):
-        """Format a Decimal instance according to the given specifier.
-
-        The specifier should be a standard format specifier, with the
-        form described in PEP 3101.  Formatting types 'e', 'E', 'f',
-        'F', 'g', 'G', 'n' and '%' are supported.  If the formatting
-        type is omitted it defaults to 'g' or 'G', depending on the
-        value of context.capitals.
-        """
-
-        # Note: PEP 3101 says that if the type is not present then
-        # there should be at least one digit after the decimal point.
-        # We take the liberty of ignoring this requirement for
-        # Decimal---it's presumably there to make sure that
-        # format(float, '') behaves similarly to str(float).
-        if context is None:
-            context = getcontext()
-
-        spec = _parse_format_specifier(specifier, _localeconv=_localeconv)
-
-        # special values don't care about the type or precision
-        if self._is_special:
-            sign = _format_sign(self._sign, spec)
-            body = str(self.copy_abs())
-            if spec['type'] == '%':
-                body += '%'
-            return _format_align(sign, body, spec)
-
-        # a type of None defaults to 'g' or 'G', depending on context
-        if spec['type'] is None:
-            spec['type'] = ['g', 'G'][context.capitals]
-
-        # if type is '%', adjust exponent of self accordingly
-        if spec['type'] == '%':
-            self = _dec_from_triple(self._sign, self._int, self._exp+2)
-
-        # round if necessary, taking rounding mode from the context
-        rounding = context.rounding
-        precision = spec['precision']
-        if precision is not None:
-            if spec['type'] in 'eE':
-                self = self._round(precision+1, rounding)
-            elif spec['type'] in 'fF%':
-                self = self._rescale(-precision, rounding)
-            elif spec['type'] in 'gG' and len(self._int) > precision:
-                self = self._round(precision, rounding)
-        # special case: zeros with a positive exponent can't be
-        # represented in fixed point; rescale them to 0e0.
-        if not self and self._exp > 0 and spec['type'] in 'fF%':
-            self = self._rescale(0, rounding)
-
-        # figure out placement of the decimal point
-        leftdigits = self._exp + len(self._int)
-        if spec['type'] in 'eE':
-            if not self and precision is not None:
-                dotplace = 1 - precision
-            else:
-                dotplace = 1
-        elif spec['type'] in 'fF%':
-            dotplace = leftdigits
-        elif spec['type'] in 'gG':
-            if self._exp <= 0 and leftdigits > -6:
-                dotplace = leftdigits
-            else:
-                dotplace = 1
-
-        # find digits before and after decimal point, and get exponent
-        if dotplace < 0:
-            intpart = '0'
-            fracpart = '0'*(-dotplace) + self._int
-        elif dotplace > len(self._int):
-            intpart = self._int + '0'*(dotplace-len(self._int))
-            fracpart = ''
-        else:
-            intpart = self._int[:dotplace] or '0'
-            fracpart = self._int[dotplace:]
-        exp = leftdigits-dotplace
-
-        # done with the decimal-specific stuff;  hand over the rest
-        # of the formatting to the _format_number function
-        return _format_number(self._sign, intpart, fracpart, exp, spec)
-
-def _dec_from_triple(sign, coefficient, exponent, special=False):
-    """Create a decimal instance directly, without any validation,
-    normalization (e.g. removal of leading zeros) or argument
-    conversion.
-
-    This function is for *internal use only*.
-    """
-
-    self = object.__new__(Decimal)
-    self._sign = sign
-    self._int = coefficient
-    self._exp = exponent
-    self._is_special = special
-
-    return self
-
-# Register Decimal as a kind of Number (an abstract base class).
-# However, do not register it as Real (because Decimals are not
-# interoperable with floats).
-_numbers.Number.register(Decimal)
-
-
-##### Context class #######################################################
-
-class _ContextManager(object):
-    """Context manager class to support localcontext().
-
-      Sets a copy of the supplied context in __enter__() and restores
-      the previous decimal context in __exit__()
-    """
-    def __init__(self, new_context):
-        self.new_context = new_context.copy()
-    def __enter__(self):
-        self.saved_context = getcontext()
-        setcontext(self.new_context)
-        return self.new_context
-    def __exit__(self, t, v, tb):
-        setcontext(self.saved_context)
-
-class Context(object):
-    """Contains the context for a Decimal instance.
-
-    Contains:
-    prec - precision (for use in rounding, division, square roots..)
-    rounding - rounding type (how you round)
-    traps - If traps[exception] = 1, then the exception is
-                    raised when it is caused.  Otherwise, a value is
-                    substituted in.
-    flags  - When an exception is caused, flags[exception] is set.
-             (Whether or not the trap_enabler is set)
-             Should be reset by user of Decimal instance.
-    Emin -   Minimum exponent
-    Emax -   Maximum exponent
-    capitals -      If 1, 1*10^1 is printed as 1E+1.
-                    If 0, printed as 1e1
-    clamp -  If 1, change exponents if too high (Default 0)
-    """
-
-    def __init__(self, prec=None, rounding=None, Emin=None, Emax=None,
-                       capitals=None, clamp=None, flags=None, traps=None,
-                       _ignored_flags=None):
-        # Set defaults; for everything except flags and _ignored_flags,
-        # inherit from DefaultContext.
-        try:
-            dc = DefaultContext
-        except NameError:
-            pass
-
-        self.prec = prec if prec is not None else dc.prec
-        self.rounding = rounding if rounding is not None else dc.rounding
-        self.Emin = Emin if Emin is not None else dc.Emin
-        self.Emax = Emax if Emax is not None else dc.Emax
-        self.capitals = capitals if capitals is not None else dc.capitals
-        self.clamp = clamp if clamp is not None else dc.clamp
-
-        if _ignored_flags is None:
-            self._ignored_flags = []
-        else:
-            self._ignored_flags = _ignored_flags
-
-        if traps is None:
-            self.traps = dc.traps.copy()
-        elif not isinstance(traps, dict):
-            self.traps = dict((s, int(s in traps)) for s in _signals + traps)
-        else:
-            self.traps = traps
-
-        if flags is None:
-            self.flags = dict.fromkeys(_signals, 0)
-        elif not isinstance(flags, dict):
-            self.flags = dict((s, int(s in flags)) for s in _signals + flags)
-        else:
-            self.flags = flags
-
-    def _set_integer_check(self, name, value, vmin, vmax):
-        if not isinstance(value, int):
-            raise TypeError("%s must be an integer" % name)
-        if vmin == '-inf':
-            if value > vmax:
-                raise ValueError("%s must be in [%s, %d]. got: %s" % (name, vmin, vmax, value))
-        elif vmax == 'inf':
-            if value < vmin:
-                raise ValueError("%s must be in [%d, %s]. got: %s" % (name, vmin, vmax, value))
-        else:
-            if value < vmin or value > vmax:
-                raise ValueError("%s must be in [%d, %d]. got %s" % (name, vmin, vmax, value))
-        return object.__setattr__(self, name, value)
-
-    def _set_signal_dict(self, name, d):
-        if not isinstance(d, dict):
-            raise TypeError("%s must be a signal dict" % d)
-        for key in d:
-            if not key in _signals:
-                raise KeyError("%s is not a valid signal dict" % d)
-        for key in _signals:
-            if not key in d:
-                raise KeyError("%s is not a valid signal dict" % d)
-        return object.__setattr__(self, name, d)
-
-    def __setattr__(self, name, value):
-        if name == 'prec':
-            return self._set_integer_check(name, value, 1, 'inf')
-        elif name == 'Emin':
-            return self._set_integer_check(name, value, '-inf', 0)
-        elif name == 'Emax':
-            return self._set_integer_check(name, value, 0, 'inf')
-        elif name == 'capitals':
-            return self._set_integer_check(name, value, 0, 1)
-        elif name == 'clamp':
-            return self._set_integer_check(name, value, 0, 1)
-        elif name == 'rounding':
-            if not value in _rounding_modes:
-                # raise TypeError even for strings to have consistency
-                # among various implementations.
-                raise TypeError("%s: invalid rounding mode" % value)
-            return object.__setattr__(self, name, value)
-        elif name == 'flags' or name == 'traps':
-            return self._set_signal_dict(name, value)
-        elif name == '_ignored_flags':
-            return object.__setattr__(self, name, value)
-        else:
-            raise AttributeError(
-                "'decimal.Context' object has no attribute '%s'" % name)
-
-    def __delattr__(self, name):
-        raise AttributeError("%s cannot be deleted" % name)
-
-    # Support for pickling, copy, and deepcopy
-    def __reduce__(self):
-        flags = [sig for sig, v in self.flags.items() if v]
-        traps = [sig for sig, v in self.traps.items() if v]
-        return (self.__class__,
-                (self.prec, self.rounding, self.Emin, self.Emax,
-                 self.capitals, self.clamp, flags, traps))
-
-    def __repr__(self):
-        """Show the current context."""
-        s = []
-        s.append('Context(prec=%(prec)d, rounding=%(rounding)s, '
-                 'Emin=%(Emin)d, Emax=%(Emax)d, capitals=%(capitals)d, '
-                 'clamp=%(clamp)d'
-                 % vars(self))
-        names = [f.__name__ for f, v in self.flags.items() if v]
-        s.append('flags=[' + ', '.join(names) + ']')
-        names = [t.__name__ for t, v in self.traps.items() if v]
-        s.append('traps=[' + ', '.join(names) + ']')
-        return ', '.join(s) + ')'
-
-    def clear_flags(self):
-        """Reset all flags to zero"""
-        for flag in self.flags:
-            self.flags[flag] = 0
-
-    def clear_traps(self):
-        """Reset all traps to zero"""
-        for flag in self.traps:
-            self.traps[flag] = 0
-
-    def _shallow_copy(self):
-        """Returns a shallow copy from self."""
-        nc = Context(self.prec, self.rounding, self.Emin, self.Emax,
-                     self.capitals, self.clamp, self.flags, self.traps,
-                     self._ignored_flags)
-        return nc
-
-    def copy(self):
-        """Returns a deep copy from self."""
-        nc = Context(self.prec, self.rounding, self.Emin, self.Emax,
-                     self.capitals, self.clamp,
-                     self.flags.copy(), self.traps.copy(),
-                     self._ignored_flags)
-        return nc
-    __copy__ = copy
-
-    def _raise_error(self, condition, explanation = None, *args):
-        """Handles an error
-
-        If the flag is in _ignored_flags, returns the default response.
-        Otherwise, it sets the flag, then, if the corresponding
-        trap_enabler is set, it reraises the exception.  Otherwise, it returns
-        the default value after setting the flag.
-        """
-        error = _condition_map.get(condition, condition)
-        if error in self._ignored_flags:
-            # Don't touch the flag
-            return error().handle(self, *args)
-
-        self.flags[error] = 1
-        if not self.traps[error]:
-            # The errors define how to handle themselves.
-            return condition().handle(self, *args)
-
-        # Errors should only be risked on copies of the context
-        # self._ignored_flags = []
-        raise error(explanation)
-
-    def _ignore_all_flags(self):
-        """Ignore all flags, if they are raised"""
-        return self._ignore_flags(*_signals)
-
-    def _ignore_flags(self, *flags):
-        """Ignore the flags, if they are raised"""
-        # Do not mutate-- This way, copies of a context leave the original
-        # alone.
-        self._ignored_flags = (self._ignored_flags + list(flags))
-        return list(flags)
-
-    def _regard_flags(self, *flags):
-        """Stop ignoring the flags, if they are raised"""
-        if flags and isinstance(flags[0], (tuple,list)):
-            flags = flags[0]
-        for flag in flags:
-            self._ignored_flags.remove(flag)
-
-    # We inherit object.__hash__, so we must deny this explicitly
-    __hash__ = None
-
-    def Etiny(self):
-        """Returns Etiny (= Emin - prec + 1)"""
-        return int(self.Emin - self.prec + 1)
-
-    def Etop(self):
-        """Returns maximum exponent (= Emax - prec + 1)"""
-        return int(self.Emax - self.prec + 1)
-
-    def _set_rounding(self, type):
-        """Sets the rounding type.
-
-        Sets the rounding type, and returns the current (previous)
-        rounding type.  Often used like:
-
-        context = context.copy()
-        # so you don't change the calling context
-        # if an error occurs in the middle.
-        rounding = context._set_rounding(ROUND_UP)
-        val = self.__sub__(other, context=context)
-        context._set_rounding(rounding)
-
-        This will make it round up for that operation.
-        """
-        rounding = self.rounding
-        self.rounding= type
-        return rounding
-
-    def create_decimal(self, num='0'):
-        """Creates a new Decimal instance but using self as context.
-
-        This method implements the to-number operation of the
-        IBM Decimal specification."""
-
-        if isinstance(num, str) and num != num.strip():
-            return self._raise_error(ConversionSyntax,
-                                     "no trailing or leading whitespace is "
-                                     "permitted.")
-
-        d = Decimal(num, context=self)
-        if d._isnan() and len(d._int) > self.prec - self.clamp:
-            return self._raise_error(ConversionSyntax,
-                                     "diagnostic info too long in NaN")
-        return d._fix(self)
-
-    def create_decimal_from_float(self, f):
-        """Creates a new Decimal instance from a float but rounding using self
-        as the context.
-
-        >>> context = Context(prec=5, rounding=ROUND_DOWN)
-        >>> context.create_decimal_from_float(3.1415926535897932)
-        Decimal('3.1415')
-        >>> context = Context(prec=5, traps=[Inexact])
-        >>> context.create_decimal_from_float(3.1415926535897932)
-        Traceback (most recent call last):
-            ...
-        decimal.Inexact: None
-
-        """
-        d = Decimal.from_float(f)       # An exact conversion
-        return d._fix(self)             # Apply the context rounding
-
-    # Methods
-    def abs(self, a):
-        """Returns the absolute value of the operand.
-
-        If the operand is negative, the result is the same as using the minus
-        operation on the operand.  Otherwise, the result is the same as using
-        the plus operation on the operand.
-
-        >>> ExtendedContext.abs(Decimal('2.1'))
-        Decimal('2.1')
-        >>> ExtendedContext.abs(Decimal('-100'))
-        Decimal('100')
-        >>> ExtendedContext.abs(Decimal('101.5'))
-        Decimal('101.5')
-        >>> ExtendedContext.abs(Decimal('-101.5'))
-        Decimal('101.5')
-        >>> ExtendedContext.abs(-1)
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.__abs__(context=self)
-
-    def add(self, a, b):
-        """Return the sum of the two operands.
-
-        >>> ExtendedContext.add(Decimal('12'), Decimal('7.00'))
-        Decimal('19.00')
-        >>> ExtendedContext.add(Decimal('1E+2'), Decimal('1.01E+4'))
-        Decimal('1.02E+4')
-        >>> ExtendedContext.add(1, Decimal(2))
-        Decimal('3')
-        >>> ExtendedContext.add(Decimal(8), 5)
-        Decimal('13')
-        >>> ExtendedContext.add(5, 5)
-        Decimal('10')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__add__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def _apply(self, a):
-        return str(a._fix(self))
-
-    def canonical(self, a):
-        """Returns the same Decimal object.
-
-        As we do not have different encodings for the same number, the
-        received object already is in its canonical form.
-
-        >>> ExtendedContext.canonical(Decimal('2.50'))
-        Decimal('2.50')
-        """
-        if not isinstance(a, Decimal):
-            raise TypeError("canonical requires a Decimal as an argument.")
-        return a.canonical()
-
-    def compare(self, a, b):
-        """Compares values numerically.
-
-        If the signs of the operands differ, a value representing each operand
-        ('-1' if the operand is less than zero, '0' if the operand is zero or
-        negative zero, or '1' if the operand is greater than zero) is used in
-        place of that operand for the comparison instead of the actual
-        operand.
-
-        The comparison is then effected by subtracting the second operand from
-        the first and then returning a value according to the result of the
-        subtraction: '-1' if the result is less than zero, '0' if the result is
-        zero or negative zero, or '1' if the result is greater than zero.
-
-        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('3'))
-        Decimal('-1')
-        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('2.1'))
-        Decimal('0')
-        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('2.10'))
-        Decimal('0')
-        >>> ExtendedContext.compare(Decimal('3'), Decimal('2.1'))
-        Decimal('1')
-        >>> ExtendedContext.compare(Decimal('2.1'), Decimal('-3'))
-        Decimal('1')
-        >>> ExtendedContext.compare(Decimal('-3'), Decimal('2.1'))
-        Decimal('-1')
-        >>> ExtendedContext.compare(1, 2)
-        Decimal('-1')
-        >>> ExtendedContext.compare(Decimal(1), 2)
-        Decimal('-1')
-        >>> ExtendedContext.compare(1, Decimal(2))
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.compare(b, context=self)
-
-    def compare_signal(self, a, b):
-        """Compares the values of the two operands numerically.
-
-        It's pretty much like compare(), but all NaNs signal, with signaling
-        NaNs taking precedence over quiet NaNs.
-
-        >>> c = ExtendedContext
-        >>> c.compare_signal(Decimal('2.1'), Decimal('3'))
-        Decimal('-1')
-        >>> c.compare_signal(Decimal('2.1'), Decimal('2.1'))
-        Decimal('0')
-        >>> c.flags[InvalidOperation] = 0
-        >>> print(c.flags[InvalidOperation])
-        0
-        >>> c.compare_signal(Decimal('NaN'), Decimal('2.1'))
-        Decimal('NaN')
-        >>> print(c.flags[InvalidOperation])
-        1
-        >>> c.flags[InvalidOperation] = 0
-        >>> print(c.flags[InvalidOperation])
-        0
-        >>> c.compare_signal(Decimal('sNaN'), Decimal('2.1'))
-        Decimal('NaN')
-        >>> print(c.flags[InvalidOperation])
-        1
-        >>> c.compare_signal(-1, 2)
-        Decimal('-1')
-        >>> c.compare_signal(Decimal(-1), 2)
-        Decimal('-1')
-        >>> c.compare_signal(-1, Decimal(2))
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.compare_signal(b, context=self)
-
-    def compare_total(self, a, b):
-        """Compares two operands using their abstract representation.
-
-        This is not like the standard compare, which use their numerical
-        value. Note that a total ordering is defined for all possible abstract
-        representations.
-
-        >>> ExtendedContext.compare_total(Decimal('12.73'), Decimal('127.9'))
-        Decimal('-1')
-        >>> ExtendedContext.compare_total(Decimal('-127'),  Decimal('12'))
-        Decimal('-1')
-        >>> ExtendedContext.compare_total(Decimal('12.30'), Decimal('12.3'))
-        Decimal('-1')
-        >>> ExtendedContext.compare_total(Decimal('12.30'), Decimal('12.30'))
-        Decimal('0')
-        >>> ExtendedContext.compare_total(Decimal('12.3'),  Decimal('12.300'))
-        Decimal('1')
-        >>> ExtendedContext.compare_total(Decimal('12.3'),  Decimal('NaN'))
-        Decimal('-1')
-        >>> ExtendedContext.compare_total(1, 2)
-        Decimal('-1')
-        >>> ExtendedContext.compare_total(Decimal(1), 2)
-        Decimal('-1')
-        >>> ExtendedContext.compare_total(1, Decimal(2))
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.compare_total(b)
-
-    def compare_total_mag(self, a, b):
-        """Compares two operands using their abstract representation ignoring sign.
-
-        Like compare_total, but with operand's sign ignored and assumed to be 0.
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.compare_total_mag(b)
-
-    def copy_abs(self, a):
-        """Returns a copy of the operand with the sign set to 0.
-
-        >>> ExtendedContext.copy_abs(Decimal('2.1'))
-        Decimal('2.1')
-        >>> ExtendedContext.copy_abs(Decimal('-100'))
-        Decimal('100')
-        >>> ExtendedContext.copy_abs(-1)
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.copy_abs()
-
-    def copy_decimal(self, a):
-        """Returns a copy of the decimal object.
-
-        >>> ExtendedContext.copy_decimal(Decimal('2.1'))
-        Decimal('2.1')
-        >>> ExtendedContext.copy_decimal(Decimal('-1.00'))
-        Decimal('-1.00')
-        >>> ExtendedContext.copy_decimal(1)
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return Decimal(a)
-
-    def copy_negate(self, a):
-        """Returns a copy of the operand with the sign inverted.
-
-        >>> ExtendedContext.copy_negate(Decimal('101.5'))
-        Decimal('-101.5')
-        >>> ExtendedContext.copy_negate(Decimal('-101.5'))
-        Decimal('101.5')
-        >>> ExtendedContext.copy_negate(1)
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.copy_negate()
-
-    def copy_sign(self, a, b):
-        """Copies the second operand's sign to the first one.
-
-        In detail, it returns a copy of the first operand with the sign
-        equal to the sign of the second operand.
-
-        >>> ExtendedContext.copy_sign(Decimal( '1.50'), Decimal('7.33'))
-        Decimal('1.50')
-        >>> ExtendedContext.copy_sign(Decimal('-1.50'), Decimal('7.33'))
-        Decimal('1.50')
-        >>> ExtendedContext.copy_sign(Decimal( '1.50'), Decimal('-7.33'))
-        Decimal('-1.50')
-        >>> ExtendedContext.copy_sign(Decimal('-1.50'), Decimal('-7.33'))
-        Decimal('-1.50')
-        >>> ExtendedContext.copy_sign(1, -2)
-        Decimal('-1')
-        >>> ExtendedContext.copy_sign(Decimal(1), -2)
-        Decimal('-1')
-        >>> ExtendedContext.copy_sign(1, Decimal(-2))
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.copy_sign(b)
-
-    def divide(self, a, b):
-        """Decimal division in a specified context.
-
-        >>> ExtendedContext.divide(Decimal('1'), Decimal('3'))
-        Decimal('0.333333333')
-        >>> ExtendedContext.divide(Decimal('2'), Decimal('3'))
-        Decimal('0.666666667')
-        >>> ExtendedContext.divide(Decimal('5'), Decimal('2'))
-        Decimal('2.5')
-        >>> ExtendedContext.divide(Decimal('1'), Decimal('10'))
-        Decimal('0.1')
-        >>> ExtendedContext.divide(Decimal('12'), Decimal('12'))
-        Decimal('1')
-        >>> ExtendedContext.divide(Decimal('8.00'), Decimal('2'))
-        Decimal('4.00')
-        >>> ExtendedContext.divide(Decimal('2.400'), Decimal('2.0'))
-        Decimal('1.20')
-        >>> ExtendedContext.divide(Decimal('1000'), Decimal('100'))
-        Decimal('10')
-        >>> ExtendedContext.divide(Decimal('1000'), Decimal('1'))
-        Decimal('1000')
-        >>> ExtendedContext.divide(Decimal('2.40E+6'), Decimal('2'))
-        Decimal('1.20E+6')
-        >>> ExtendedContext.divide(5, 5)
-        Decimal('1')
-        >>> ExtendedContext.divide(Decimal(5), 5)
-        Decimal('1')
-        >>> ExtendedContext.divide(5, Decimal(5))
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__truediv__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def divide_int(self, a, b):
-        """Divides two numbers and returns the integer part of the result.
-
-        >>> ExtendedContext.divide_int(Decimal('2'), Decimal('3'))
-        Decimal('0')
-        >>> ExtendedContext.divide_int(Decimal('10'), Decimal('3'))
-        Decimal('3')
-        >>> ExtendedContext.divide_int(Decimal('1'), Decimal('0.3'))
-        Decimal('3')
-        >>> ExtendedContext.divide_int(10, 3)
-        Decimal('3')
-        >>> ExtendedContext.divide_int(Decimal(10), 3)
-        Decimal('3')
-        >>> ExtendedContext.divide_int(10, Decimal(3))
-        Decimal('3')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__floordiv__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def divmod(self, a, b):
-        """Return (a // b, a % b).
-
-        >>> ExtendedContext.divmod(Decimal(8), Decimal(3))
-        (Decimal('2'), Decimal('2'))
-        >>> ExtendedContext.divmod(Decimal(8), Decimal(4))
-        (Decimal('2'), Decimal('0'))
-        >>> ExtendedContext.divmod(8, 4)
-        (Decimal('2'), Decimal('0'))
-        >>> ExtendedContext.divmod(Decimal(8), 4)
-        (Decimal('2'), Decimal('0'))
-        >>> ExtendedContext.divmod(8, Decimal(4))
-        (Decimal('2'), Decimal('0'))
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__divmod__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def exp(self, a):
-        """Returns e ** a.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.exp(Decimal('-Infinity'))
-        Decimal('0')
-        >>> c.exp(Decimal('-1'))
-        Decimal('0.367879441')
-        >>> c.exp(Decimal('0'))
-        Decimal('1')
-        >>> c.exp(Decimal('1'))
-        Decimal('2.71828183')
-        >>> c.exp(Decimal('0.693147181'))
-        Decimal('2.00000000')
-        >>> c.exp(Decimal('+Infinity'))
-        Decimal('Infinity')
-        >>> c.exp(10)
-        Decimal('22026.4658')
-        """
-        a =_convert_other(a, raiseit=True)
-        return a.exp(context=self)
-
-    def fma(self, a, b, c):
-        """Returns a multiplied by b, plus c.
-
-        The first two operands are multiplied together, using multiply,
-        the third operand is then added to the result of that
-        multiplication, using add, all with only one final rounding.
-
-        >>> ExtendedContext.fma(Decimal('3'), Decimal('5'), Decimal('7'))
-        Decimal('22')
-        >>> ExtendedContext.fma(Decimal('3'), Decimal('-5'), Decimal('7'))
-        Decimal('-8')
-        >>> ExtendedContext.fma(Decimal('888565290'), Decimal('1557.96930'), Decimal('-86087.7578'))
-        Decimal('1.38435736E+12')
-        >>> ExtendedContext.fma(1, 3, 4)
-        Decimal('7')
-        >>> ExtendedContext.fma(1, Decimal(3), 4)
-        Decimal('7')
-        >>> ExtendedContext.fma(1, 3, Decimal(4))
-        Decimal('7')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.fma(b, c, context=self)
-
-    def is_canonical(self, a):
-        """Return True if the operand is canonical; otherwise return False.
-
-        Currently, the encoding of a Decimal instance is always
-        canonical, so this method returns True for any Decimal.
-
-        >>> ExtendedContext.is_canonical(Decimal('2.50'))
-        True
-        """
-        if not isinstance(a, Decimal):
-            raise TypeError("is_canonical requires a Decimal as an argument.")
-        return a.is_canonical()
-
-    def is_finite(self, a):
-        """Return True if the operand is finite; otherwise return False.
-
-        A Decimal instance is considered finite if it is neither
-        infinite nor a NaN.
-
-        >>> ExtendedContext.is_finite(Decimal('2.50'))
-        True
-        >>> ExtendedContext.is_finite(Decimal('-0.3'))
-        True
-        >>> ExtendedContext.is_finite(Decimal('0'))
-        True
-        >>> ExtendedContext.is_finite(Decimal('Inf'))
-        False
-        >>> ExtendedContext.is_finite(Decimal('NaN'))
-        False
-        >>> ExtendedContext.is_finite(1)
-        True
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_finite()
-
-    def is_infinite(self, a):
-        """Return True if the operand is infinite; otherwise return False.
-
-        >>> ExtendedContext.is_infinite(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_infinite(Decimal('-Inf'))
-        True
-        >>> ExtendedContext.is_infinite(Decimal('NaN'))
-        False
-        >>> ExtendedContext.is_infinite(1)
-        False
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_infinite()
-
-    def is_nan(self, a):
-        """Return True if the operand is a qNaN or sNaN;
-        otherwise return False.
-
-        >>> ExtendedContext.is_nan(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_nan(Decimal('NaN'))
-        True
-        >>> ExtendedContext.is_nan(Decimal('-sNaN'))
-        True
-        >>> ExtendedContext.is_nan(1)
-        False
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_nan()
-
-    def is_normal(self, a):
-        """Return True if the operand is a normal number;
-        otherwise return False.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.is_normal(Decimal('2.50'))
-        True
-        >>> c.is_normal(Decimal('0.1E-999'))
-        False
-        >>> c.is_normal(Decimal('0.00'))
-        False
-        >>> c.is_normal(Decimal('-Inf'))
-        False
-        >>> c.is_normal(Decimal('NaN'))
-        False
-        >>> c.is_normal(1)
-        True
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_normal(context=self)
-
-    def is_qnan(self, a):
-        """Return True if the operand is a quiet NaN; otherwise return False.
-
-        >>> ExtendedContext.is_qnan(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_qnan(Decimal('NaN'))
-        True
-        >>> ExtendedContext.is_qnan(Decimal('sNaN'))
-        False
-        >>> ExtendedContext.is_qnan(1)
-        False
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_qnan()
-
-    def is_signed(self, a):
-        """Return True if the operand is negative; otherwise return False.
-
-        >>> ExtendedContext.is_signed(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_signed(Decimal('-12'))
-        True
-        >>> ExtendedContext.is_signed(Decimal('-0'))
-        True
-        >>> ExtendedContext.is_signed(8)
-        False
-        >>> ExtendedContext.is_signed(-8)
-        True
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_signed()
-
-    def is_snan(self, a):
-        """Return True if the operand is a signaling NaN;
-        otherwise return False.
-
-        >>> ExtendedContext.is_snan(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_snan(Decimal('NaN'))
-        False
-        >>> ExtendedContext.is_snan(Decimal('sNaN'))
-        True
-        >>> ExtendedContext.is_snan(1)
-        False
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_snan()
-
-    def is_subnormal(self, a):
-        """Return True if the operand is subnormal; otherwise return False.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.is_subnormal(Decimal('2.50'))
-        False
-        >>> c.is_subnormal(Decimal('0.1E-999'))
-        True
-        >>> c.is_subnormal(Decimal('0.00'))
-        False
-        >>> c.is_subnormal(Decimal('-Inf'))
-        False
-        >>> c.is_subnormal(Decimal('NaN'))
-        False
-        >>> c.is_subnormal(1)
-        False
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_subnormal(context=self)
-
-    def is_zero(self, a):
-        """Return True if the operand is a zero; otherwise return False.
-
-        >>> ExtendedContext.is_zero(Decimal('0'))
-        True
-        >>> ExtendedContext.is_zero(Decimal('2.50'))
-        False
-        >>> ExtendedContext.is_zero(Decimal('-0E+2'))
-        True
-        >>> ExtendedContext.is_zero(1)
-        False
-        >>> ExtendedContext.is_zero(0)
-        True
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.is_zero()
-
-    def ln(self, a):
-        """Returns the natural (base e) logarithm of the operand.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.ln(Decimal('0'))
-        Decimal('-Infinity')
-        >>> c.ln(Decimal('1.000'))
-        Decimal('0')
-        >>> c.ln(Decimal('2.71828183'))
-        Decimal('1.00000000')
-        >>> c.ln(Decimal('10'))
-        Decimal('2.30258509')
-        >>> c.ln(Decimal('+Infinity'))
-        Decimal('Infinity')
-        >>> c.ln(1)
-        Decimal('0')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.ln(context=self)
-
-    def log10(self, a):
-        """Returns the base 10 logarithm of the operand.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.log10(Decimal('0'))
-        Decimal('-Infinity')
-        >>> c.log10(Decimal('0.001'))
-        Decimal('-3')
-        >>> c.log10(Decimal('1.000'))
-        Decimal('0')
-        >>> c.log10(Decimal('2'))
-        Decimal('0.301029996')
-        >>> c.log10(Decimal('10'))
-        Decimal('1')
-        >>> c.log10(Decimal('70'))
-        Decimal('1.84509804')
-        >>> c.log10(Decimal('+Infinity'))
-        Decimal('Infinity')
-        >>> c.log10(0)
-        Decimal('-Infinity')
-        >>> c.log10(1)
-        Decimal('0')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.log10(context=self)
-
-    def logb(self, a):
-        """ Returns the exponent of the magnitude of the operand's MSD.
-
-        The result is the integer which is the exponent of the magnitude
-        of the most significant digit of the operand (as though the
-        operand were truncated to a single digit while maintaining the
-        value of that digit and without limiting the resulting exponent).
-
-        >>> ExtendedContext.logb(Decimal('250'))
-        Decimal('2')
-        >>> ExtendedContext.logb(Decimal('2.50'))
-        Decimal('0')
-        >>> ExtendedContext.logb(Decimal('0.03'))
-        Decimal('-2')
-        >>> ExtendedContext.logb(Decimal('0'))
-        Decimal('-Infinity')
-        >>> ExtendedContext.logb(1)
-        Decimal('0')
-        >>> ExtendedContext.logb(10)
-        Decimal('1')
-        >>> ExtendedContext.logb(100)
-        Decimal('2')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.logb(context=self)
-
-    def logical_and(self, a, b):
-        """Applies the logical operation 'and' between each operand's digits.
-
-        The operands must be both logical numbers.
-
-        >>> ExtendedContext.logical_and(Decimal('0'), Decimal('0'))
-        Decimal('0')
-        >>> ExtendedContext.logical_and(Decimal('0'), Decimal('1'))
-        Decimal('0')
-        >>> ExtendedContext.logical_and(Decimal('1'), Decimal('0'))
-        Decimal('0')
-        >>> ExtendedContext.logical_and(Decimal('1'), Decimal('1'))
-        Decimal('1')
-        >>> ExtendedContext.logical_and(Decimal('1100'), Decimal('1010'))
-        Decimal('1000')
-        >>> ExtendedContext.logical_and(Decimal('1111'), Decimal('10'))
-        Decimal('10')
-        >>> ExtendedContext.logical_and(110, 1101)
-        Decimal('100')
-        >>> ExtendedContext.logical_and(Decimal(110), 1101)
-        Decimal('100')
-        >>> ExtendedContext.logical_and(110, Decimal(1101))
-        Decimal('100')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.logical_and(b, context=self)
-
-    def logical_invert(self, a):
-        """Invert all the digits in the operand.
-
-        The operand must be a logical number.
-
-        >>> ExtendedContext.logical_invert(Decimal('0'))
-        Decimal('111111111')
-        >>> ExtendedContext.logical_invert(Decimal('1'))
-        Decimal('111111110')
-        >>> ExtendedContext.logical_invert(Decimal('111111111'))
-        Decimal('0')
-        >>> ExtendedContext.logical_invert(Decimal('101010101'))
-        Decimal('10101010')
-        >>> ExtendedContext.logical_invert(1101)
-        Decimal('111110010')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.logical_invert(context=self)
-
-    def logical_or(self, a, b):
-        """Applies the logical operation 'or' between each operand's digits.
-
-        The operands must be both logical numbers.
-
-        >>> ExtendedContext.logical_or(Decimal('0'), Decimal('0'))
-        Decimal('0')
-        >>> ExtendedContext.logical_or(Decimal('0'), Decimal('1'))
-        Decimal('1')
-        >>> ExtendedContext.logical_or(Decimal('1'), Decimal('0'))
-        Decimal('1')
-        >>> ExtendedContext.logical_or(Decimal('1'), Decimal('1'))
-        Decimal('1')
-        >>> ExtendedContext.logical_or(Decimal('1100'), Decimal('1010'))
-        Decimal('1110')
-        >>> ExtendedContext.logical_or(Decimal('1110'), Decimal('10'))
-        Decimal('1110')
-        >>> ExtendedContext.logical_or(110, 1101)
-        Decimal('1111')
-        >>> ExtendedContext.logical_or(Decimal(110), 1101)
-        Decimal('1111')
-        >>> ExtendedContext.logical_or(110, Decimal(1101))
-        Decimal('1111')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.logical_or(b, context=self)
-
-    def logical_xor(self, a, b):
-        """Applies the logical operation 'xor' between each operand's digits.
-
-        The operands must be both logical numbers.
-
-        >>> ExtendedContext.logical_xor(Decimal('0'), Decimal('0'))
-        Decimal('0')
-        >>> ExtendedContext.logical_xor(Decimal('0'), Decimal('1'))
-        Decimal('1')
-        >>> ExtendedContext.logical_xor(Decimal('1'), Decimal('0'))
-        Decimal('1')
-        >>> ExtendedContext.logical_xor(Decimal('1'), Decimal('1'))
-        Decimal('0')
-        >>> ExtendedContext.logical_xor(Decimal('1100'), Decimal('1010'))
-        Decimal('110')
-        >>> ExtendedContext.logical_xor(Decimal('1111'), Decimal('10'))
-        Decimal('1101')
-        >>> ExtendedContext.logical_xor(110, 1101)
-        Decimal('1011')
-        >>> ExtendedContext.logical_xor(Decimal(110), 1101)
-        Decimal('1011')
-        >>> ExtendedContext.logical_xor(110, Decimal(1101))
-        Decimal('1011')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.logical_xor(b, context=self)
-
-    def max(self, a, b):
-        """max compares two values numerically and returns the maximum.
-
-        If either operand is a NaN then the general rules apply.
-        Otherwise, the operands are compared as though by the compare
-        operation.  If they are numerically equal then the left-hand operand
-        is chosen as the result.  Otherwise the maximum (closer to positive
-        infinity) of the two operands is chosen as the result.
-
-        >>> ExtendedContext.max(Decimal('3'), Decimal('2'))
-        Decimal('3')
-        >>> ExtendedContext.max(Decimal('-10'), Decimal('3'))
-        Decimal('3')
-        >>> ExtendedContext.max(Decimal('1.0'), Decimal('1'))
-        Decimal('1')
-        >>> ExtendedContext.max(Decimal('7'), Decimal('NaN'))
-        Decimal('7')
-        >>> ExtendedContext.max(1, 2)
-        Decimal('2')
-        >>> ExtendedContext.max(Decimal(1), 2)
-        Decimal('2')
-        >>> ExtendedContext.max(1, Decimal(2))
-        Decimal('2')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.max(b, context=self)
-
-    def max_mag(self, a, b):
-        """Compares the values numerically with their sign ignored.
-
-        >>> ExtendedContext.max_mag(Decimal('7'), Decimal('NaN'))
-        Decimal('7')
-        >>> ExtendedContext.max_mag(Decimal('7'), Decimal('-10'))
-        Decimal('-10')
-        >>> ExtendedContext.max_mag(1, -2)
-        Decimal('-2')
-        >>> ExtendedContext.max_mag(Decimal(1), -2)
-        Decimal('-2')
-        >>> ExtendedContext.max_mag(1, Decimal(-2))
-        Decimal('-2')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.max_mag(b, context=self)
-
-    def min(self, a, b):
-        """min compares two values numerically and returns the minimum.
-
-        If either operand is a NaN then the general rules apply.
-        Otherwise, the operands are compared as though by the compare
-        operation.  If they are numerically equal then the left-hand operand
-        is chosen as the result.  Otherwise the minimum (closer to negative
-        infinity) of the two operands is chosen as the result.
-
-        >>> ExtendedContext.min(Decimal('3'), Decimal('2'))
-        Decimal('2')
-        >>> ExtendedContext.min(Decimal('-10'), Decimal('3'))
-        Decimal('-10')
-        >>> ExtendedContext.min(Decimal('1.0'), Decimal('1'))
-        Decimal('1.0')
-        >>> ExtendedContext.min(Decimal('7'), Decimal('NaN'))
-        Decimal('7')
-        >>> ExtendedContext.min(1, 2)
-        Decimal('1')
-        >>> ExtendedContext.min(Decimal(1), 2)
-        Decimal('1')
-        >>> ExtendedContext.min(1, Decimal(29))
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.min(b, context=self)
-
-    def min_mag(self, a, b):
-        """Compares the values numerically with their sign ignored.
-
-        >>> ExtendedContext.min_mag(Decimal('3'), Decimal('-2'))
-        Decimal('-2')
-        >>> ExtendedContext.min_mag(Decimal('-3'), Decimal('NaN'))
-        Decimal('-3')
-        >>> ExtendedContext.min_mag(1, -2)
-        Decimal('1')
-        >>> ExtendedContext.min_mag(Decimal(1), -2)
-        Decimal('1')
-        >>> ExtendedContext.min_mag(1, Decimal(-2))
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.min_mag(b, context=self)
-
-    def minus(self, a):
-        """Minus corresponds to unary prefix minus in Python.
-
-        The operation is evaluated using the same rules as subtract; the
-        operation minus(a) is calculated as subtract('0', a) where the '0'
-        has the same exponent as the operand.
-
-        >>> ExtendedContext.minus(Decimal('1.3'))
-        Decimal('-1.3')
-        >>> ExtendedContext.minus(Decimal('-1.3'))
-        Decimal('1.3')
-        >>> ExtendedContext.minus(1)
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.__neg__(context=self)
-
-    def multiply(self, a, b):
-        """multiply multiplies two operands.
-
-        If either operand is a special value then the general rules apply.
-        Otherwise, the operands are multiplied together
-        ('long multiplication'), resulting in a number which may be as long as
-        the sum of the lengths of the two operands.
-
-        >>> ExtendedContext.multiply(Decimal('1.20'), Decimal('3'))
-        Decimal('3.60')
-        >>> ExtendedContext.multiply(Decimal('7'), Decimal('3'))
-        Decimal('21')
-        >>> ExtendedContext.multiply(Decimal('0.9'), Decimal('0.8'))
-        Decimal('0.72')
-        >>> ExtendedContext.multiply(Decimal('0.9'), Decimal('-0'))
-        Decimal('-0.0')
-        >>> ExtendedContext.multiply(Decimal('654321'), Decimal('654321'))
-        Decimal('4.28135971E+11')
-        >>> ExtendedContext.multiply(7, 7)
-        Decimal('49')
-        >>> ExtendedContext.multiply(Decimal(7), 7)
-        Decimal('49')
-        >>> ExtendedContext.multiply(7, Decimal(7))
-        Decimal('49')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__mul__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def next_minus(self, a):
-        """Returns the largest representable number smaller than a.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> ExtendedContext.next_minus(Decimal('1'))
-        Decimal('0.999999999')
-        >>> c.next_minus(Decimal('1E-1007'))
-        Decimal('0E-1007')
-        >>> ExtendedContext.next_minus(Decimal('-1.00000003'))
-        Decimal('-1.00000004')
-        >>> c.next_minus(Decimal('Infinity'))
-        Decimal('9.99999999E+999')
-        >>> c.next_minus(1)
-        Decimal('0.999999999')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.next_minus(context=self)
-
-    def next_plus(self, a):
-        """Returns the smallest representable number larger than a.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> ExtendedContext.next_plus(Decimal('1'))
-        Decimal('1.00000001')
-        >>> c.next_plus(Decimal('-1E-1007'))
-        Decimal('-0E-1007')
-        >>> ExtendedContext.next_plus(Decimal('-1.00000003'))
-        Decimal('-1.00000002')
-        >>> c.next_plus(Decimal('-Infinity'))
-        Decimal('-9.99999999E+999')
-        >>> c.next_plus(1)
-        Decimal('1.00000001')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.next_plus(context=self)
-
-    def next_toward(self, a, b):
-        """Returns the number closest to a, in direction towards b.
-
-        The result is the closest representable number from the first
-        operand (but not the first operand) that is in the direction
-        towards the second operand, unless the operands have the same
-        value.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.next_toward(Decimal('1'), Decimal('2'))
-        Decimal('1.00000001')
-        >>> c.next_toward(Decimal('-1E-1007'), Decimal('1'))
-        Decimal('-0E-1007')
-        >>> c.next_toward(Decimal('-1.00000003'), Decimal('0'))
-        Decimal('-1.00000002')
-        >>> c.next_toward(Decimal('1'), Decimal('0'))
-        Decimal('0.999999999')
-        >>> c.next_toward(Decimal('1E-1007'), Decimal('-100'))
-        Decimal('0E-1007')
-        >>> c.next_toward(Decimal('-1.00000003'), Decimal('-10'))
-        Decimal('-1.00000004')
-        >>> c.next_toward(Decimal('0.00'), Decimal('-0.0000'))
-        Decimal('-0.00')
-        >>> c.next_toward(0, 1)
-        Decimal('1E-1007')
-        >>> c.next_toward(Decimal(0), 1)
-        Decimal('1E-1007')
-        >>> c.next_toward(0, Decimal(1))
-        Decimal('1E-1007')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.next_toward(b, context=self)
-
-    def normalize(self, a):
-        """normalize reduces an operand to its simplest form.
-
-        Essentially a plus operation with all trailing zeros removed from the
-        result.
-
-        >>> ExtendedContext.normalize(Decimal('2.1'))
-        Decimal('2.1')
-        >>> ExtendedContext.normalize(Decimal('-2.0'))
-        Decimal('-2')
-        >>> ExtendedContext.normalize(Decimal('1.200'))
-        Decimal('1.2')
-        >>> ExtendedContext.normalize(Decimal('-120'))
-        Decimal('-1.2E+2')
-        >>> ExtendedContext.normalize(Decimal('120.00'))
-        Decimal('1.2E+2')
-        >>> ExtendedContext.normalize(Decimal('0.00'))
-        Decimal('0')
-        >>> ExtendedContext.normalize(6)
-        Decimal('6')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.normalize(context=self)
-
-    def number_class(self, a):
-        """Returns an indication of the class of the operand.
-
-        The class is one of the following strings:
-          -sNaN
-          -NaN
-          -Infinity
-          -Normal
-          -Subnormal
-          -Zero
-          +Zero
-          +Subnormal
-          +Normal
-          +Infinity
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.number_class(Decimal('Infinity'))
-        '+Infinity'
-        >>> c.number_class(Decimal('1E-10'))
-        '+Normal'
-        >>> c.number_class(Decimal('2.50'))
-        '+Normal'
-        >>> c.number_class(Decimal('0.1E-999'))
-        '+Subnormal'
-        >>> c.number_class(Decimal('0'))
-        '+Zero'
-        >>> c.number_class(Decimal('-0'))
-        '-Zero'
-        >>> c.number_class(Decimal('-0.1E-999'))
-        '-Subnormal'
-        >>> c.number_class(Decimal('-1E-10'))
-        '-Normal'
-        >>> c.number_class(Decimal('-2.50'))
-        '-Normal'
-        >>> c.number_class(Decimal('-Infinity'))
-        '-Infinity'
-        >>> c.number_class(Decimal('NaN'))
-        'NaN'
-        >>> c.number_class(Decimal('-NaN'))
-        'NaN'
-        >>> c.number_class(Decimal('sNaN'))
-        'sNaN'
-        >>> c.number_class(123)
-        '+Normal'
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.number_class(context=self)
-
-    def plus(self, a):
-        """Plus corresponds to unary prefix plus in Python.
-
-        The operation is evaluated using the same rules as add; the
-        operation plus(a) is calculated as add('0', a) where the '0'
-        has the same exponent as the operand.
-
-        >>> ExtendedContext.plus(Decimal('1.3'))
-        Decimal('1.3')
-        >>> ExtendedContext.plus(Decimal('-1.3'))
-        Decimal('-1.3')
-        >>> ExtendedContext.plus(-1)
-        Decimal('-1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.__pos__(context=self)
-
-    def power(self, a, b, modulo=None):
-        """Raises a to the power of b, to modulo if given.
-
-        With two arguments, compute a**b.  If a is negative then b
-        must be integral.  The result will be inexact unless b is
-        integral and the result is finite and can be expressed exactly
-        in 'precision' digits.
-
-        With three arguments, compute (a**b) % modulo.  For the
-        three argument form, the following restrictions on the
-        arguments hold:
-
-         - all three arguments must be integral
-         - b must be nonnegative
-         - at least one of a or b must be nonzero
-         - modulo must be nonzero and have at most 'precision' digits
-
-        The result of pow(a, b, modulo) is identical to the result
-        that would be obtained by computing (a**b) % modulo with
-        unbounded precision, but is computed more efficiently.  It is
-        always exact.
-
-        >>> c = ExtendedContext.copy()
-        >>> c.Emin = -999
-        >>> c.Emax = 999
-        >>> c.power(Decimal('2'), Decimal('3'))
-        Decimal('8')
-        >>> c.power(Decimal('-2'), Decimal('3'))
-        Decimal('-8')
-        >>> c.power(Decimal('2'), Decimal('-3'))
-        Decimal('0.125')
-        >>> c.power(Decimal('1.7'), Decimal('8'))
-        Decimal('69.7575744')
-        >>> c.power(Decimal('10'), Decimal('0.301029996'))
-        Decimal('2.00000000')
-        >>> c.power(Decimal('Infinity'), Decimal('-1'))
-        Decimal('0')
-        >>> c.power(Decimal('Infinity'), Decimal('0'))
-        Decimal('1')
-        >>> c.power(Decimal('Infinity'), Decimal('1'))
-        Decimal('Infinity')
-        >>> c.power(Decimal('-Infinity'), Decimal('-1'))
-        Decimal('-0')
-        >>> c.power(Decimal('-Infinity'), Decimal('0'))
-        Decimal('1')
-        >>> c.power(Decimal('-Infinity'), Decimal('1'))
-        Decimal('-Infinity')
-        >>> c.power(Decimal('-Infinity'), Decimal('2'))
-        Decimal('Infinity')
-        >>> c.power(Decimal('0'), Decimal('0'))
-        Decimal('NaN')
-
-        >>> c.power(Decimal('3'), Decimal('7'), Decimal('16'))
-        Decimal('11')
-        >>> c.power(Decimal('-3'), Decimal('7'), Decimal('16'))
-        Decimal('-11')
-        >>> c.power(Decimal('-3'), Decimal('8'), Decimal('16'))
-        Decimal('1')
-        >>> c.power(Decimal('3'), Decimal('7'), Decimal('-16'))
-        Decimal('11')
-        >>> c.power(Decimal('23E12345'), Decimal('67E189'), Decimal('123456789'))
-        Decimal('11729830')
-        >>> c.power(Decimal('-0'), Decimal('17'), Decimal('1729'))
-        Decimal('-0')
-        >>> c.power(Decimal('-23'), Decimal('0'), Decimal('65537'))
-        Decimal('1')
-        >>> ExtendedContext.power(7, 7)
-        Decimal('823543')
-        >>> ExtendedContext.power(Decimal(7), 7)
-        Decimal('823543')
-        >>> ExtendedContext.power(7, Decimal(7), 2)
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__pow__(b, modulo, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def quantize(self, a, b):
-        """Returns a value equal to 'a' (rounded), having the exponent of 'b'.
-
-        The coefficient of the result is derived from that of the left-hand
-        operand.  It may be rounded using the current rounding setting (if the
-        exponent is being increased), multiplied by a positive power of ten (if
-        the exponent is being decreased), or is unchanged (if the exponent is
-        already equal to that of the right-hand operand).
-
-        Unlike other operations, if the length of the coefficient after the
-        quantize operation would be greater than precision then an Invalid
-        operation condition is raised.  This guarantees that, unless there is
-        an error condition, the exponent of the result of a quantize is always
-        equal to that of the right-hand operand.
-
-        Also unlike other operations, quantize will never raise Underflow, even
-        if the result is subnormal and inexact.
-
-        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.001'))
-        Decimal('2.170')
-        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.01'))
-        Decimal('2.17')
-        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('0.1'))
-        Decimal('2.2')
-        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('1e+0'))
-        Decimal('2')
-        >>> ExtendedContext.quantize(Decimal('2.17'), Decimal('1e+1'))
-        Decimal('0E+1')
-        >>> ExtendedContext.quantize(Decimal('-Inf'), Decimal('Infinity'))
-        Decimal('-Infinity')
-        >>> ExtendedContext.quantize(Decimal('2'), Decimal('Infinity'))
-        Decimal('NaN')
-        >>> ExtendedContext.quantize(Decimal('-0.1'), Decimal('1'))
-        Decimal('-0')
-        >>> ExtendedContext.quantize(Decimal('-0'), Decimal('1e+5'))
-        Decimal('-0E+5')
-        >>> ExtendedContext.quantize(Decimal('+35236450.6'), Decimal('1e-2'))
-        Decimal('NaN')
-        >>> ExtendedContext.quantize(Decimal('-35236450.6'), Decimal('1e-2'))
-        Decimal('NaN')
-        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e-1'))
-        Decimal('217.0')
-        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e-0'))
-        Decimal('217')
-        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e+1'))
-        Decimal('2.2E+2')
-        >>> ExtendedContext.quantize(Decimal('217'), Decimal('1e+2'))
-        Decimal('2E+2')
-        >>> ExtendedContext.quantize(1, 2)
-        Decimal('1')
-        >>> ExtendedContext.quantize(Decimal(1), 2)
-        Decimal('1')
-        >>> ExtendedContext.quantize(1, Decimal(2))
-        Decimal('1')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.quantize(b, context=self)
-
-    def radix(self):
-        """Just returns 10, as this is Decimal, :)
-
-        >>> ExtendedContext.radix()
-        Decimal('10')
-        """
-        return Decimal(10)
-
-    def remainder(self, a, b):
-        """Returns the remainder from integer division.
-
-        The result is the residue of the dividend after the operation of
-        calculating integer division as described for divide-integer, rounded
-        to precision digits if necessary.  The sign of the result, if
-        non-zero, is the same as that of the original dividend.
-
-        This operation will fail under the same conditions as integer division
-        (that is, if integer division on the same two operands would fail, the
-        remainder cannot be calculated).
-
-        >>> ExtendedContext.remainder(Decimal('2.1'), Decimal('3'))
-        Decimal('2.1')
-        >>> ExtendedContext.remainder(Decimal('10'), Decimal('3'))
-        Decimal('1')
-        >>> ExtendedContext.remainder(Decimal('-10'), Decimal('3'))
-        Decimal('-1')
-        >>> ExtendedContext.remainder(Decimal('10.2'), Decimal('1'))
-        Decimal('0.2')
-        >>> ExtendedContext.remainder(Decimal('10'), Decimal('0.3'))
-        Decimal('0.1')
-        >>> ExtendedContext.remainder(Decimal('3.6'), Decimal('1.3'))
-        Decimal('1.0')
-        >>> ExtendedContext.remainder(22, 6)
-        Decimal('4')
-        >>> ExtendedContext.remainder(Decimal(22), 6)
-        Decimal('4')
-        >>> ExtendedContext.remainder(22, Decimal(6))
-        Decimal('4')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__mod__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def remainder_near(self, a, b):
-        """Returns to be "a - b * n", where n is the integer nearest the exact
-        value of "x / b" (if two integers are equally near then the even one
-        is chosen).  If the result is equal to 0 then its sign will be the
-        sign of a.
-
-        This operation will fail under the same conditions as integer division
-        (that is, if integer division on the same two operands would fail, the
-        remainder cannot be calculated).
-
-        >>> ExtendedContext.remainder_near(Decimal('2.1'), Decimal('3'))
-        Decimal('-0.9')
-        >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('6'))
-        Decimal('-2')
-        >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('3'))
-        Decimal('1')
-        >>> ExtendedContext.remainder_near(Decimal('-10'), Decimal('3'))
-        Decimal('-1')
-        >>> ExtendedContext.remainder_near(Decimal('10.2'), Decimal('1'))
-        Decimal('0.2')
-        >>> ExtendedContext.remainder_near(Decimal('10'), Decimal('0.3'))
-        Decimal('0.1')
-        >>> ExtendedContext.remainder_near(Decimal('3.6'), Decimal('1.3'))
-        Decimal('-0.3')
-        >>> ExtendedContext.remainder_near(3, 11)
-        Decimal('3')
-        >>> ExtendedContext.remainder_near(Decimal(3), 11)
-        Decimal('3')
-        >>> ExtendedContext.remainder_near(3, Decimal(11))
-        Decimal('3')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.remainder_near(b, context=self)
-
-    def rotate(self, a, b):
-        """Returns a rotated copy of a, b times.
-
-        The coefficient of the result is a rotated copy of the digits in
-        the coefficient of the first operand.  The number of places of
-        rotation is taken from the absolute value of the second operand,
-        with the rotation being to the left if the second operand is
-        positive or to the right otherwise.
-
-        >>> ExtendedContext.rotate(Decimal('34'), Decimal('8'))
-        Decimal('400000003')
-        >>> ExtendedContext.rotate(Decimal('12'), Decimal('9'))
-        Decimal('12')
-        >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('-2'))
-        Decimal('891234567')
-        >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('0'))
-        Decimal('123456789')
-        >>> ExtendedContext.rotate(Decimal('123456789'), Decimal('+2'))
-        Decimal('345678912')
-        >>> ExtendedContext.rotate(1333333, 1)
-        Decimal('13333330')
-        >>> ExtendedContext.rotate(Decimal(1333333), 1)
-        Decimal('13333330')
-        >>> ExtendedContext.rotate(1333333, Decimal(1))
-        Decimal('13333330')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.rotate(b, context=self)
-
-    def same_quantum(self, a, b):
-        """Returns True if the two operands have the same exponent.
-
-        The result is never affected by either the sign or the coefficient of
-        either operand.
-
-        >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('0.001'))
-        False
-        >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('0.01'))
-        True
-        >>> ExtendedContext.same_quantum(Decimal('2.17'), Decimal('1'))
-        False
-        >>> ExtendedContext.same_quantum(Decimal('Inf'), Decimal('-Inf'))
-        True
-        >>> ExtendedContext.same_quantum(10000, -1)
-        True
-        >>> ExtendedContext.same_quantum(Decimal(10000), -1)
-        True
-        >>> ExtendedContext.same_quantum(10000, Decimal(-1))
-        True
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.same_quantum(b)
-
-    def scaleb (self, a, b):
-        """Returns the first operand after adding the second value its exp.
-
-        >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('-2'))
-        Decimal('0.0750')
-        >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('0'))
-        Decimal('7.50')
-        >>> ExtendedContext.scaleb(Decimal('7.50'), Decimal('3'))
-        Decimal('7.50E+3')
-        >>> ExtendedContext.scaleb(1, 4)
-        Decimal('1E+4')
-        >>> ExtendedContext.scaleb(Decimal(1), 4)
-        Decimal('1E+4')
-        >>> ExtendedContext.scaleb(1, Decimal(4))
-        Decimal('1E+4')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.scaleb(b, context=self)
-
-    def shift(self, a, b):
-        """Returns a shifted copy of a, b times.
-
-        The coefficient of the result is a shifted copy of the digits
-        in the coefficient of the first operand.  The number of places
-        to shift is taken from the absolute value of the second operand,
-        with the shift being to the left if the second operand is
-        positive or to the right otherwise.  Digits shifted into the
-        coefficient are zeros.
-
-        >>> ExtendedContext.shift(Decimal('34'), Decimal('8'))
-        Decimal('400000000')
-        >>> ExtendedContext.shift(Decimal('12'), Decimal('9'))
-        Decimal('0')
-        >>> ExtendedContext.shift(Decimal('123456789'), Decimal('-2'))
-        Decimal('1234567')
-        >>> ExtendedContext.shift(Decimal('123456789'), Decimal('0'))
-        Decimal('123456789')
-        >>> ExtendedContext.shift(Decimal('123456789'), Decimal('+2'))
-        Decimal('345678900')
-        >>> ExtendedContext.shift(88888888, 2)
-        Decimal('888888800')
-        >>> ExtendedContext.shift(Decimal(88888888), 2)
-        Decimal('888888800')
-        >>> ExtendedContext.shift(88888888, Decimal(2))
-        Decimal('888888800')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.shift(b, context=self)
-
-    def sqrt(self, a):
-        """Square root of a non-negative number to context precision.
-
-        If the result must be inexact, it is rounded using the round-half-even
-        algorithm.
-
-        >>> ExtendedContext.sqrt(Decimal('0'))
-        Decimal('0')
-        >>> ExtendedContext.sqrt(Decimal('-0'))
-        Decimal('-0')
-        >>> ExtendedContext.sqrt(Decimal('0.39'))
-        Decimal('0.624499800')
-        >>> ExtendedContext.sqrt(Decimal('100'))
-        Decimal('10')
-        >>> ExtendedContext.sqrt(Decimal('1'))
-        Decimal('1')
-        >>> ExtendedContext.sqrt(Decimal('1.0'))
-        Decimal('1.0')
-        >>> ExtendedContext.sqrt(Decimal('1.00'))
-        Decimal('1.0')
-        >>> ExtendedContext.sqrt(Decimal('7'))
-        Decimal('2.64575131')
-        >>> ExtendedContext.sqrt(Decimal('10'))
-        Decimal('3.16227766')
-        >>> ExtendedContext.sqrt(2)
-        Decimal('1.41421356')
-        >>> ExtendedContext.prec
-        9
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.sqrt(context=self)
-
-    def subtract(self, a, b):
-        """Return the difference between the two operands.
-
-        >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('1.07'))
-        Decimal('0.23')
-        >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('1.30'))
-        Decimal('0.00')
-        >>> ExtendedContext.subtract(Decimal('1.3'), Decimal('2.07'))
-        Decimal('-0.77')
-        >>> ExtendedContext.subtract(8, 5)
-        Decimal('3')
-        >>> ExtendedContext.subtract(Decimal(8), 5)
-        Decimal('3')
-        >>> ExtendedContext.subtract(8, Decimal(5))
-        Decimal('3')
-        """
-        a = _convert_other(a, raiseit=True)
-        r = a.__sub__(b, context=self)
-        if r is NotImplemented:
-            raise TypeError("Unable to convert %s to Decimal" % b)
-        else:
-            return r
-
-    def to_eng_string(self, a):
-        """Converts a number to a string, using scientific notation.
-
-        The operation is not affected by the context.
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.to_eng_string(context=self)
-
-    def to_sci_string(self, a):
-        """Converts a number to a string, using scientific notation.
-
-        The operation is not affected by the context.
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.__str__(context=self)
-
-    def to_integral_exact(self, a):
-        """Rounds to an integer.
-
-        When the operand has a negative exponent, the result is the same
-        as using the quantize() operation using the given operand as the
-        left-hand-operand, 1E+0 as the right-hand-operand, and the precision
-        of the operand as the precision setting; Inexact and Rounded flags
-        are allowed in this operation.  The rounding mode is taken from the
-        context.
-
-        >>> ExtendedContext.to_integral_exact(Decimal('2.1'))
-        Decimal('2')
-        >>> ExtendedContext.to_integral_exact(Decimal('100'))
-        Decimal('100')
-        >>> ExtendedContext.to_integral_exact(Decimal('100.0'))
-        Decimal('100')
-        >>> ExtendedContext.to_integral_exact(Decimal('101.5'))
-        Decimal('102')
-        >>> ExtendedContext.to_integral_exact(Decimal('-101.5'))
-        Decimal('-102')
-        >>> ExtendedContext.to_integral_exact(Decimal('10E+5'))
-        Decimal('1.0E+6')
-        >>> ExtendedContext.to_integral_exact(Decimal('7.89E+77'))
-        Decimal('7.89E+77')
-        >>> ExtendedContext.to_integral_exact(Decimal('-Inf'))
-        Decimal('-Infinity')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.to_integral_exact(context=self)
-
-    def to_integral_value(self, a):
-        """Rounds to an integer.
-
-        When the operand has a negative exponent, the result is the same
-        as using the quantize() operation using the given operand as the
-        left-hand-operand, 1E+0 as the right-hand-operand, and the precision
-        of the operand as the precision setting, except that no flags will
-        be set.  The rounding mode is taken from the context.
-
-        >>> ExtendedContext.to_integral_value(Decimal('2.1'))
-        Decimal('2')
-        >>> ExtendedContext.to_integral_value(Decimal('100'))
-        Decimal('100')
-        >>> ExtendedContext.to_integral_value(Decimal('100.0'))
-        Decimal('100')
-        >>> ExtendedContext.to_integral_value(Decimal('101.5'))
-        Decimal('102')
-        >>> ExtendedContext.to_integral_value(Decimal('-101.5'))
-        Decimal('-102')
-        >>> ExtendedContext.to_integral_value(Decimal('10E+5'))
-        Decimal('1.0E+6')
-        >>> ExtendedContext.to_integral_value(Decimal('7.89E+77'))
-        Decimal('7.89E+77')
-        >>> ExtendedContext.to_integral_value(Decimal('-Inf'))
-        Decimal('-Infinity')
-        """
-        a = _convert_other(a, raiseit=True)
-        return a.to_integral_value(context=self)
-
-    # the method name changed, but we provide also the old one, for compatibility
-    to_integral = to_integral_value
-
-class _WorkRep(object):
-    __slots__ = ('sign','int','exp')
-    # sign: 0 or 1
-    # int:  int
-    # exp:  None, int, or string
-
-    def __init__(self, value=None):
-        if value is None:
-            self.sign = None
-            self.int = 0
-            self.exp = None
-        elif isinstance(value, Decimal):
-            self.sign = value._sign
-            self.int = int(value._int)
-            self.exp = value._exp
-        else:
-            # assert isinstance(value, tuple)
-            self.sign = value[0]
-            self.int = value[1]
-            self.exp = value[2]
-
-    def __repr__(self):
-        return "(%r, %r, %r)" % (self.sign, self.int, self.exp)
-
-    __str__ = __repr__
-
-
-
-def _normalize(op1, op2, prec = 0):
-    """Normalizes op1, op2 to have the same exp and length of coefficient.
-
-    Done during addition.
-    """
-    if op1.exp < op2.exp:
-        tmp = op2
-        other = op1
-    else:
-        tmp = op1
-        other = op2
-
-    # Let exp = min(tmp.exp - 1, tmp.adjusted() - precision - 1).
-    # Then adding 10**exp to tmp has the same effect (after rounding)
-    # as adding any positive quantity smaller than 10**exp; similarly
-    # for subtraction.  So if other is smaller than 10**exp we replace
-    # it with 10**exp.  This avoids tmp.exp - other.exp getting too large.
-    tmp_len = len(str(tmp.int))
-    other_len = len(str(other.int))
-    exp = tmp.exp + min(-1, tmp_len - prec - 2)
-    if other_len + other.exp - 1 < exp:
-        other.int = 1
-        other.exp = exp
-
-    tmp.int *= 10 ** (tmp.exp - other.exp)
-    tmp.exp = other.exp
-    return op1, op2
-
-##### Integer arithmetic functions used by ln, log10, exp and __pow__ #####
-
-_nbits = int.bit_length
-
-def _decimal_lshift_exact(n, e):
-    """ Given integers n and e, return n * 10**e if it's an integer, else None.
-
-    The computation is designed to avoid computing large powers of 10
-    unnecessarily.
-
-    >>> _decimal_lshift_exact(3, 4)
-    30000
-    >>> _decimal_lshift_exact(300, -999999999)  # returns None
-
-    """
-    if n == 0:
-        return 0
-    elif e >= 0:
-        return n * 10**e
-    else:
-        # val_n = largest power of 10 dividing n.
-        str_n = str(abs(n))
-        val_n = len(str_n) - len(str_n.rstrip('0'))
-        return None if val_n < -e else n // 10**-e
-
-def _sqrt_nearest(n, a):
-    """Closest integer to the square root of the positive integer n.  a is
-    an initial approximation to the square root.  Any positive integer
-    will do for a, but the closer a is to the square root of n the
-    faster convergence will be.
-
-    """
-    if n <= 0 or a <= 0:
-        raise ValueError("Both arguments to _sqrt_nearest should be positive.")
-
-    b=0
-    while a != b:
-        b, a = a, a--n//a>>1
-    return a
-
-def _rshift_nearest(x, shift):
-    """Given an integer x and a nonnegative integer shift, return closest
-    integer to x / 2**shift; use round-to-even in case of a tie.
-
-    """
-    b, q = 1 << shift, x >> shift
-    return q + (2*(x & (b-1)) + (q&1) > b)
-
-def _div_nearest(a, b):
-    """Closest integer to a/b, a and b positive integers; rounds to even
-    in the case of a tie.
-
-    """
-    q, r = divmod(a, b)
-    return q + (2*r + (q&1) > b)
-
-def _ilog(x, M, L = 8):
-    """Integer approximation to M*log(x/M), with absolute error boundable
-    in terms only of x/M.
-
-    Given positive integers x and M, return an integer approximation to
-    M * log(x/M).  For L = 8 and 0.1 <= x/M <= 10 the difference
-    between the approximation and the exact result is at most 22.  For
-    L = 8 and 1.0 <= x/M <= 10.0 the difference is at most 15.  In
-    both cases these are upper bounds on the error; it will usually be
-    much smaller."""
-
-    # The basic algorithm is the following: let log1p be the function
-    # log1p(x) = log(1+x).  Then log(x/M) = log1p((x-M)/M).  We use
-    # the reduction
-    #
-    #    log1p(y) = 2*log1p(y/(1+sqrt(1+y)))
-    #
-    # repeatedly until the argument to log1p is small (< 2**-L in
-    # absolute value).  For small y we can use the Taylor series
-    # expansion
-    #
-    #    log1p(y) ~ y - y**2/2 + y**3/3 - ... - (-y)**T/T
-    #
-    # truncating at T such that y**T is small enough.  The whole
-    # computation is carried out in a form of fixed-point arithmetic,
-    # with a real number z being represented by an integer
-    # approximation to z*M.  To avoid loss of precision, the y below
-    # is actually an integer approximation to 2**R*y*M, where R is the
-    # number of reductions performed so far.
-
-    y = x-M
-    # argument reduction; R = number of reductions performed
-    R = 0
-    while (R <= L and abs(y) << L-R >= M or
-           R > L and abs(y) >> R-L >= M):
-        y = _div_nearest((M*y) << 1,
-                         M + _sqrt_nearest(M*(M+_rshift_nearest(y, R)), M))
-        R += 1
-
-    # Taylor series with T terms
-    T = -int(-10*len(str(M))//(3*L))
-    yshift = _rshift_nearest(y, R)
-    w = _div_nearest(M, T)
-    for k in range(T-1, 0, -1):
-        w = _div_nearest(M, k) - _div_nearest(yshift*w, M)
-
-    return _div_nearest(w*y, M)
-
-def _dlog10(c, e, p):
-    """Given integers c, e and p with c > 0, p >= 0, compute an integer
-    approximation to 10**p * log10(c*10**e), with an absolute error of
-    at most 1.  Assumes that c*10**e is not exactly 1."""
-
-    # increase precision by 2; compensate for this by dividing
-    # final result by 100
-    p += 2
-
-    # write c*10**e as d*10**f with either:
-    #   f >= 0 and 1 <= d <= 10, or
-    #   f <= 0 and 0.1 <= d <= 1.
-    # Thus for c*10**e close to 1, f = 0
-    l = len(str(c))
-    f = e+l - (e+l >= 1)
-
-    if p > 0:
-        M = 10**p
-        k = e+p-f
-        if k >= 0:
-            c *= 10**k
-        else:
-            c = _div_nearest(c, 10**-k)
-
-        log_d = _ilog(c, M) # error < 5 + 22 = 27
-        log_10 = _log10_digits(p) # error < 1
-        log_d = _div_nearest(log_d*M, log_10)
-        log_tenpower = f*M # exact
-    else:
-        log_d = 0  # error < 2.31
-        log_tenpower = _div_nearest(f, 10**-p) # error < 0.5
-
-    return _div_nearest(log_tenpower+log_d, 100)
-
-def _dlog(c, e, p):
-    """Given integers c, e and p with c > 0, compute an integer
-    approximation to 10**p * log(c*10**e), with an absolute error of
-    at most 1.  Assumes that c*10**e is not exactly 1."""
-
-    # Increase precision by 2. The precision increase is compensated
-    # for at the end with a division by 100.
-    p += 2
-
-    # rewrite c*10**e as d*10**f with either f >= 0 and 1 <= d <= 10,
-    # or f <= 0 and 0.1 <= d <= 1.  Then we can compute 10**p * log(c*10**e)
-    # as 10**p * log(d) + 10**p*f * log(10).
-    l = len(str(c))
-    f = e+l - (e+l >= 1)
-
-    # compute approximation to 10**p*log(d), with error < 27
-    if p > 0:
-        k = e+p-f
-        if k >= 0:
-            c *= 10**k
-        else:
-            c = _div_nearest(c, 10**-k)  # error of <= 0.5 in c
-
-        # _ilog magnifies existing error in c by a factor of at most 10
-        log_d = _ilog(c, 10**p) # error < 5 + 22 = 27
-    else:
-        # p <= 0: just approximate the whole thing by 0; error < 2.31
-        log_d = 0
-
-    # compute approximation to f*10**p*log(10), with error < 11.
-    if f:
-        extra = len(str(abs(f)))-1
-        if p + extra >= 0:
-            # error in f * _log10_digits(p+extra) < |f| * 1 = |f|
-            # after division, error < |f|/10**extra + 0.5 < 10 + 0.5 < 11
-            f_log_ten = _div_nearest(f*_log10_digits(p+extra), 10**extra)
-        else:
-            f_log_ten = 0
-    else:
-        f_log_ten = 0
-
-    # error in sum < 11+27 = 38; error after division < 0.38 + 0.5 < 1
-    return _div_nearest(f_log_ten + log_d, 100)
-
-class _Log10Memoize(object):
-    """Class to compute, store, and allow retrieval of, digits of the
-    constant log(10) = 2.302585....  This constant is needed by
-    Decimal.ln, Decimal.log10, Decimal.exp and Decimal.__pow__."""
-    def __init__(self):
-        self.digits = "23025850929940456840179914546843642076011014886"
-
-    def getdigits(self, p):
-        """Given an integer p >= 0, return floor(10**p)*log(10).
-
-        For example, self.getdigits(3) returns 2302.
-        """
-        # digits are stored as a string, for quick conversion to
-        # integer in the case that we've already computed enough
-        # digits; the stored digits should always be correct
-        # (truncated, not rounded to nearest).
-        if p < 0:
-            raise ValueError("p should be nonnegative")
-
-        if p >= len(self.digits):
-            # compute p+3, p+6, p+9, ... digits; continue until at
-            # least one of the extra digits is nonzero
-            extra = 3
-            while True:
-                # compute p+extra digits, correct to within 1ulp
-                M = 10**(p+extra+2)
-                digits = str(_div_nearest(_ilog(10*M, M), 100))
-                if digits[-extra:] != '0'*extra:
-                    break
-                extra += 3
-            # keep all reliable digits so far; remove trailing zeros
-            # and next nonzero digit
-            self.digits = digits.rstrip('0')[:-1]
-        return int(self.digits[:p+1])
-
-_log10_digits = _Log10Memoize().getdigits
-
-def _iexp(x, M, L=8):
-    """Given integers x and M, M > 0, such that x/M is small in absolute
-    value, compute an integer approximation to M*exp(x/M).  For 0 <=
-    x/M <= 2.4, the absolute error in the result is bounded by 60 (and
-    is usually much smaller)."""
-
-    # Algorithm: to compute exp(z) for a real number z, first divide z
-    # by a suitable power R of 2 so that |z/2**R| < 2**-L.  Then
-    # compute expm1(z/2**R) = exp(z/2**R) - 1 using the usual Taylor
-    # series
-    #
-    #     expm1(x) = x + x**2/2! + x**3/3! + ...
-    #
-    # Now use the identity
-    #
-    #     expm1(2x) = expm1(x)*(expm1(x)+2)
-    #
-    # R times to compute the sequence expm1(z/2**R),
-    # expm1(z/2**(R-1)), ... , exp(z/2), exp(z).
-
-    # Find R such that x/2**R/M <= 2**-L
-    R = _nbits((x<<L)//M)
-
-    # Taylor series.  (2**L)**T > M
-    T = -int(-10*len(str(M))//(3*L))
-    y = _div_nearest(x, T)
-    Mshift = M<<R
-    for i in range(T-1, 0, -1):
-        y = _div_nearest(x*(Mshift + y), Mshift * i)
-
-    # Expansion
-    for k in range(R-1, -1, -1):
-        Mshift = M<<(k+2)
-        y = _div_nearest(y*(y+Mshift), Mshift)
-
-    return M+y
-
-def _dexp(c, e, p):
-    """Compute an approximation to exp(c*10**e), with p decimal places of
-    precision.
-
-    Returns integers d, f such that:
-
-      10**(p-1) <= d <= 10**p, and
-      (d-1)*10**f < exp(c*10**e) < (d+1)*10**f
-
-    In other words, d*10**f is an approximation to exp(c*10**e) with p
-    digits of precision, and with an error in d of at most 1.  This is
-    almost, but not quite, the same as the error being < 1ulp: when d
-    = 10**(p-1) the error could be up to 10 ulp."""
-
-    # we'll call iexp with M = 10**(p+2), giving p+3 digits of precision
-    p += 2
-
-    # compute log(10) with extra precision = adjusted exponent of c*10**e
-    extra = max(0, e + len(str(c)) - 1)
-    q = p + extra
-
-    # compute quotient c*10**e/(log(10)) = c*10**(e+q)/(log(10)*10**q),
-    # rounding down
-    shift = e+q
-    if shift >= 0:
-        cshift = c*10**shift
-    else:
-        cshift = c//10**-shift
-    quot, rem = divmod(cshift, _log10_digits(q))
-
-    # reduce remainder back to original precision
-    rem = _div_nearest(rem, 10**extra)
-
-    # error in result of _iexp < 120;  error after division < 0.62
-    return _div_nearest(_iexp(rem, 10**p), 1000), quot - p + 3
-
-def _dpower(xc, xe, yc, ye, p):
-    """Given integers xc, xe, yc and ye representing Decimals x = xc*10**xe and
-    y = yc*10**ye, compute x**y.  Returns a pair of integers (c, e) such that:
-
-      10**(p-1) <= c <= 10**p, and
-      (c-1)*10**e < x**y < (c+1)*10**e
-
-    in other words, c*10**e is an approximation to x**y with p digits
-    of precision, and with an error in c of at most 1.  (This is
-    almost, but not quite, the same as the error being < 1ulp: when c
-    == 10**(p-1) we can only guarantee error < 10ulp.)
-
-    We assume that: x is positive and not equal to 1, and y is nonzero.
-    """
-
-    # Find b such that 10**(b-1) <= |y| <= 10**b
-    b = len(str(abs(yc))) + ye
-
-    # log(x) = lxc*10**(-p-b-1), to p+b+1 places after the decimal point
-    lxc = _dlog(xc, xe, p+b+1)
-
-    # compute product y*log(x) = yc*lxc*10**(-p-b-1+ye) = pc*10**(-p-1)
-    shift = ye-b
-    if shift >= 0:
-        pc = lxc*yc*10**shift
-    else:
-        pc = _div_nearest(lxc*yc, 10**-shift)
-
-    if pc == 0:
-        # we prefer a result that isn't exactly 1; this makes it
-        # easier to compute a correctly rounded result in __pow__
-        if ((len(str(xc)) + xe >= 1) == (yc > 0)): # if x**y > 1:
-            coeff, exp = 10**(p-1)+1, 1-p
-        else:
-            coeff, exp = 10**p-1, -p
-    else:
-        coeff, exp = _dexp(pc, -(p+1), p+1)
-        coeff = _div_nearest(coeff, 10)
-        exp += 1
-
-    return coeff, exp
-
-def _log10_lb(c, correction = {
-        '1': 100, '2': 70, '3': 53, '4': 40, '5': 31,
-        '6': 23, '7': 16, '8': 10, '9': 5}):
-    """Compute a lower bound for 100*log10(c) for a positive integer c."""
-    if c <= 0:
-        raise ValueError("The argument to _log10_lb should be nonnegative.")
-    str_c = str(c)
-    return 100*len(str_c) - correction[str_c[0]]
-
-##### Helper Functions ####################################################
-
-def _convert_other(other, raiseit=False, allow_float=False):
-    """Convert other to Decimal.
-
-    Verifies that it's ok to use in an implicit construction.
-    If allow_float is true, allow conversion from float;  this
-    is used in the comparison methods (__eq__ and friends).
-
-    """
-    if isinstance(other, Decimal):
-        return other
-    if isinstance(other, int):
-        return Decimal(other)
-    if allow_float and isinstance(other, float):
-        return Decimal.from_float(other)
-
-    if raiseit:
-        raise TypeError("Unable to convert %s to Decimal" % other)
-    return NotImplemented
-
-def _convert_for_comparison(self, other, equality_op=False):
-    """Given a Decimal instance self and a Python object other, return
-    a pair (s, o) of Decimal instances such that "s op o" is
-    equivalent to "self op other" for any of the 6 comparison
-    operators "op".
-
-    """
-    if isinstance(other, Decimal):
-        return self, other
-
-    # Comparison with a Rational instance (also includes integers):
-    # self op n/d <=> self*d op n (for n and d integers, d positive).
-    # A NaN or infinity can be left unchanged without affecting the
-    # comparison result.
-    if isinstance(other, _numbers.Rational):
-        if not self._is_special:
-            self = _dec_from_triple(self._sign,
-                                    str(int(self._int) * other.denominator),
-                                    self._exp)
-        return self, Decimal(other.numerator)
-
-    # Comparisons with float and complex types.  == and != comparisons
-    # with complex numbers should succeed, returning either True or False
-    # as appropriate.  Other comparisons return NotImplemented.
-    if equality_op and isinstance(other, _numbers.Complex) and other.imag == 0:
-        other = other.real
-    if isinstance(other, float):
-        context = getcontext()
-        if equality_op:
-            context.flags[FloatOperation] = 1
-        else:
-            context._raise_error(FloatOperation,
-                "strict semantics for mixing floats and Decimals are enabled")
-        return self, Decimal.from_float(other)
-    return NotImplemented, NotImplemented
-
-
-##### Setup Specific Contexts ############################################
-
-# The default context prototype used by Context()
-# Is mutable, so that new contexts can have different default values
-
-DefaultContext = Context(
-        prec=28, rounding=ROUND_HALF_EVEN,
-        traps=[DivisionByZero, Overflow, InvalidOperation],
-        flags=[],
-        Emax=999999,
-        Emin=-999999,
-        capitals=1,
-        clamp=0
-)
-
-# Pre-made alternate contexts offered by the specification
-# Don't change these; the user should be able to select these
-# contexts and be able to reproduce results from other implementations
-# of the spec.
-
-BasicContext = Context(
-        prec=9, rounding=ROUND_HALF_UP,
-        traps=[DivisionByZero, Overflow, InvalidOperation, Clamped, Underflow],
-        flags=[],
-)
-
-ExtendedContext = Context(
-        prec=9, rounding=ROUND_HALF_EVEN,
-        traps=[],
-        flags=[],
-)
-
-
-##### crud for parsing strings #############################################
-#
-# Regular expression used for parsing numeric strings.  Additional
-# comments:
-#
-# 1. Uncomment the two '\s*' lines to allow leading and/or trailing
-# whitespace.  But note that the specification disallows whitespace in
-# a numeric string.
-#
-# 2. For finite numbers (not infinities and NaNs) the body of the
-# number between the optional sign and the optional exponent must have
-# at least one decimal digit, possibly after the decimal point.  The
-# lookahead expression '(?=\d|\.\d)' checks this.
-
-import re
-_parser = re.compile(r"""        # A numeric string consists of:
-#    \s*
-    (?P<sign>[-+])?              # an optional sign, followed by either...
-    (
-        (?=\d|\.\d)              # ...a number (with at least one digit)
-        (?P<int>\d*)             # having a (possibly empty) integer part
-        (\.(?P<frac>\d*))?       # followed by an optional fractional part
-        (E(?P<exp>[-+]?\d+))?    # followed by an optional exponent, or...
-    |
-        Inf(inity)?              # ...an infinity, or...
-    |
-        (?P<signal>s)?           # ...an (optionally signaling)
-        NaN                      # NaN
-        (?P<diag>\d*)            # with (possibly empty) diagnostic info.
-    )
-#    \s*
-    \Z
-""", re.VERBOSE | re.IGNORECASE).match
-
-_all_zeros = re.compile('0*$').match
-_exact_half = re.compile('50*$').match
-
-##### PEP3101 support functions ##############################################
-# The functions in this section have little to do with the Decimal
-# class, and could potentially be reused or adapted for other pure
-# Python numeric classes that want to implement __format__
-#
-# A format specifier for Decimal looks like:
-#
-#   [[fill]align][sign][#][0][minimumwidth][,][.precision][type]
-
-_parse_format_specifier_regex = re.compile(r"""\A
-(?:
-   (?P<fill>.)?
-   (?P<align>[<>=^])
-)?
-(?P<sign>[-+ ])?
-(?P<alt>\#)?
-(?P<zeropad>0)?
-(?P<minimumwidth>(?!0)\d+)?
-(?P<thousands_sep>,)?
-(?:\.(?P<precision>0|(?!0)\d+))?
-(?P<type>[eEfFgGn%])?
-\Z
-""", re.VERBOSE|re.DOTALL)
-
-del re
-
-# The locale module is only needed for the 'n' format specifier.  The
-# rest of the PEP 3101 code functions quite happily without it, so we
-# don't care too much if locale isn't present.
-try:
-    import locale as _locale
-except ImportError:
-    pass
-
-def _parse_format_specifier(format_spec, _localeconv=None):
-    """Parse and validate a format specifier.
-
-    Turns a standard numeric format specifier into a dict, with the
-    following entries:
-
-      fill: fill character to pad field to minimum width
-      align: alignment type, either '<', '>', '=' or '^'
-      sign: either '+', '-' or ' '
-      minimumwidth: nonnegative integer giving minimum width
-      zeropad: boolean, indicating whether to pad with zeros
-      thousands_sep: string to use as thousands separator, or ''
-      grouping: grouping for thousands separators, in format
-        used by localeconv
-      decimal_point: string to use for decimal point
-      precision: nonnegative integer giving precision, or None
-      type: one of the characters 'eEfFgG%', or None
-
-    """
-    m = _parse_format_specifier_regex.match(format_spec)
-    if m is None:
-        raise ValueError("Invalid format specifier: " + format_spec)
-
-    # get the dictionary
-    format_dict = m.groupdict()
-
-    # zeropad; defaults for fill and alignment.  If zero padding
-    # is requested, the fill and align fields should be absent.
-    fill = format_dict['fill']
-    align = format_dict['align']
-    format_dict['zeropad'] = (format_dict['zeropad'] is not None)
-    if format_dict['zeropad']:
-        if fill is not None:
-            raise ValueError("Fill character conflicts with '0'"
-                             " in format specifier: " + format_spec)
-        if align is not None:
-            raise ValueError("Alignment conflicts with '0' in "
-                             "format specifier: " + format_spec)
-    format_dict['fill'] = fill or ' '
-    # PEP 3101 originally specified that the default alignment should
-    # be left;  it was later agreed that right-aligned makes more sense
-    # for numeric types.  See http://bugs.python.org/issue6857.
-    format_dict['align'] = align or '>'
-
-    # default sign handling: '-' for negative, '' for positive
-    if format_dict['sign'] is None:
-        format_dict['sign'] = '-'
-
-    # minimumwidth defaults to 0; precision remains None if not given
-    format_dict['minimumwidth'] = int(format_dict['minimumwidth'] or '0')
-    if format_dict['precision'] is not None:
-        format_dict['precision'] = int(format_dict['precision'])
-
-    # if format type is 'g' or 'G' then a precision of 0 makes little
-    # sense; convert it to 1.  Same if format type is unspecified.
-    if format_dict['precision'] == 0:
-        if format_dict['type'] is None or format_dict['type'] in 'gGn':
-            format_dict['precision'] = 1
-
-    # determine thousands separator, grouping, and decimal separator, and
-    # add appropriate entries to format_dict
-    if format_dict['type'] == 'n':
-        # apart from separators, 'n' behaves just like 'g'
-        format_dict['type'] = 'g'
-        if _localeconv is None:
-            _localeconv = _locale.localeconv()
-        if format_dict['thousands_sep'] is not None:
-            raise ValueError("Explicit thousands separator conflicts with "
-                             "'n' type in format specifier: " + format_spec)
-        format_dict['thousands_sep'] = _localeconv['thousands_sep']
-        format_dict['grouping'] = _localeconv['grouping']
-        format_dict['decimal_point'] = _localeconv['decimal_point']
-    else:
-        if format_dict['thousands_sep'] is None:
-            format_dict['thousands_sep'] = ''
-        format_dict['grouping'] = [3, 0]
-        format_dict['decimal_point'] = '.'
-
-    return format_dict
-
-def _format_align(sign, body, spec):
-    """Given an unpadded, non-aligned numeric string 'body' and sign
-    string 'sign', add padding and alignment conforming to the given
-    format specifier dictionary 'spec' (as produced by
-    parse_format_specifier).
-
-    """
-    # how much extra space do we have to play with?
-    minimumwidth = spec['minimumwidth']
-    fill = spec['fill']
-    padding = fill*(minimumwidth - len(sign) - len(body))
-
-    align = spec['align']
-    if align == '<':
-        result = sign + body + padding
-    elif align == '>':
-        result = padding + sign + body
-    elif align == '=':
-        result = sign + padding + body
-    elif align == '^':
-        half = len(padding)//2
-        result = padding[:half] + sign + body + padding[half:]
-    else:
-        raise ValueError('Unrecognised alignment field')
-
-    return result
-
-def _group_lengths(grouping):
-    """Convert a localeconv-style grouping into a (possibly infinite)
-    iterable of integers representing group lengths.
-
-    """
-    # The result from localeconv()['grouping'], and the input to this
-    # function, should be a list of integers in one of the
-    # following three forms:
-    #
-    #   (1) an empty list, or
-    #   (2) nonempty list of positive integers + [0]
-    #   (3) list of positive integers + [locale.CHAR_MAX], or
-
-    from itertools import chain, repeat
-    if not grouping:
-        return []
-    elif grouping[-1] == 0 and len(grouping) >= 2:
-        return chain(grouping[:-1], repeat(grouping[-2]))
-    elif grouping[-1] == _locale.CHAR_MAX:
-        return grouping[:-1]
-    else:
-        raise ValueError('unrecognised format for grouping')
-
-def _insert_thousands_sep(digits, spec, min_width=1):
-    """Insert thousands separators into a digit string.
-
-    spec is a dictionary whose keys should include 'thousands_sep' and
-    'grouping'; typically it's the result of parsing the format
-    specifier using _parse_format_specifier.
-
-    The min_width keyword argument gives the minimum length of the
-    result, which will be padded on the left with zeros if necessary.
-
-    If necessary, the zero padding adds an extra '0' on the left to
-    avoid a leading thousands separator.  For example, inserting
-    commas every three digits in '123456', with min_width=8, gives
-    '0,123,456', even though that has length 9.
-
-    """
-
-    sep = spec['thousands_sep']
-    grouping = spec['grouping']
-
-    groups = []
-    for l in _group_lengths(grouping):
-        if l <= 0:
-            raise ValueError("group length should be positive")
-        # max(..., 1) forces at least 1 digit to the left of a separator
-        l = min(max(len(digits), min_width, 1), l)
-        groups.append('0'*(l - len(digits)) + digits[-l:])
-        digits = digits[:-l]
-        min_width -= l
-        if not digits and min_width <= 0:
-            break
-        min_width -= len(sep)
-    else:
-        l = max(len(digits), min_width, 1)
-        groups.append('0'*(l - len(digits)) + digits[-l:])
-    return sep.join(reversed(groups))
-
-def _format_sign(is_negative, spec):
-    """Determine sign character."""
-
-    if is_negative:
-        return '-'
-    elif spec['sign'] in ' +':
-        return spec['sign']
-    else:
-        return ''
-
-def _format_number(is_negative, intpart, fracpart, exp, spec):
-    """Format a number, given the following data:
-
-    is_negative: true if the number is negative, else false
-    intpart: string of digits that must appear before the decimal point
-    fracpart: string of digits that must come after the point
-    exp: exponent, as an integer
-    spec: dictionary resulting from parsing the format specifier
-
-    This function uses the information in spec to:
-      insert separators (decimal separator and thousands separators)
-      format the sign
-      format the exponent
-      add trailing '%' for the '%' type
-      zero-pad if necessary
-      fill and align if necessary
-    """
-
-    sign = _format_sign(is_negative, spec)
-
-    if fracpart or spec['alt']:
-        fracpart = spec['decimal_point'] + fracpart
-
-    if exp != 0 or spec['type'] in 'eE':
-        echar = {'E': 'E', 'e': 'e', 'G': 'E', 'g': 'e'}[spec['type']]
-        fracpart += "{0}{1:+}".format(echar, exp)
-    if spec['type'] == '%':
-        fracpart += '%'
-
-    if spec['zeropad']:
-        min_width = spec['minimumwidth'] - len(fracpart) - len(sign)
-    else:
-        min_width = 0
-    intpart = _insert_thousands_sep(intpart, spec, min_width)
-
-    return _format_align(sign, intpart+fracpart, spec)
-
-
-##### Useful Constants (internal use only) ################################
-
-# Reusable defaults
-_Infinity = Decimal('Inf')
-_NegativeInfinity = Decimal('-Inf')
-_NaN = Decimal('NaN')
-_Zero = Decimal(0)
-_One = Decimal(1)
-_NegativeOne = Decimal(-1)
-
-# _SignedInfinity[sign] is infinity w/ that sign
-_SignedInfinity = (_Infinity, _NegativeInfinity)
-
-# Constants related to the hash implementation;  hash(x) is based
-# on the reduction of x modulo _PyHASH_MODULUS
-_PyHASH_MODULUS = sys.hash_info.modulus
-# hash values to use for positive and negative infinities, and nans
-_PyHASH_INF = sys.hash_info.inf
-_PyHASH_NAN = sys.hash_info.nan
-
-# _PyHASH_10INV is the inverse of 10 modulo the prime _PyHASH_MODULUS
-_PyHASH_10INV = pow(10, _PyHASH_MODULUS - 2, _PyHASH_MODULUS)
-del sys
 
 try:
-    import _decimal
-except ImportError:
-    pass
-else:
-    s1 = set(dir())
-    s2 = set(dir(_decimal))
-    for name in s1 - s2:
-        del globals()[name]
-    del s1, s2, name
     from _decimal import *
-
-if __name__ == '__main__':
-    import doctest, decimal
-    doctest.testmod(decimal)
+    from _decimal import __doc__
+    from _decimal import __version__
+    from _decimal import __libmpdec_version__
+except ImportError:
+    from _pydecimal import *
+    from _pydecimal import __doc__
+    from _pydecimal import __version__
+    from _pydecimal import __libmpdec_version__
diff --git a/Lib/difflib.py b/Lib/difflib.py
index 7eb42a9..96fd9ab 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -28,9 +28,9 @@ Class HtmlDiff:
 
 __all__ = ['get_close_matches', 'ndiff', 'restore', 'SequenceMatcher',
            'Differ','IS_CHARACTER_JUNK', 'IS_LINE_JUNK', 'context_diff',
-           'unified_diff', 'HtmlDiff', 'Match']
+           'unified_diff', 'diff_bytes', 'HtmlDiff', 'Match']
 
-import heapq
+from heapq import nlargest as _nlargest
 from collections import namedtuple as _namedtuple
 
 Match = _namedtuple('Match', 'a b size')
@@ -729,7 +729,7 @@ def get_close_matches(word, possibilities, n=3, cutoff=0.6):
             result.append((s.ratio(), x))
 
     # Move the best scorers to head of list
-    result = heapq.nlargest(n, result)
+    result = _nlargest(n, result)
     # Strip scores for the best n matches
     return [x for score, x in result]
 
@@ -852,10 +852,9 @@ class Differ:
           and return true iff the string is junk. The module-level function
           `IS_LINE_JUNK` may be used to filter out lines without visible
           characters, except for at most one splat ('#').  It is recommended
-          to leave linejunk None; as of Python 2.3, the underlying
-          SequenceMatcher class has grown an adaptive notion of "noise" lines
-          that's better than any static definition the author has ever been
-          able to craft.
+          to leave linejunk None; the underlying SequenceMatcher class has
+          an adaptive notion of "noise" lines that's better than any static
+          definition the author has ever been able to craft.
 
         - `charjunk`: A function that should accept a string of length 1. The
           module-level function `IS_CHARACTER_JUNK` may be used to filter out
@@ -1175,6 +1174,7 @@ def unified_diff(a, b, fromfile='', tofile='', fromfiledate='',
      four
     """
 
+    _check_types(a, b, fromfile, tofile, fromfiledate, tofiledate, lineterm)
     started = False
     for group in SequenceMatcher(None,a,b).get_grouped_opcodes(n):
         if not started:
@@ -1262,6 +1262,7 @@ def context_diff(a, b, fromfile='', tofile='',
       four
     """
 
+    _check_types(a, b, fromfile, tofile, fromfiledate, tofiledate, lineterm)
     prefix = dict(insert='+ ', delete='- ', replace='! ', equal='  ')
     started = False
     for group in SequenceMatcher(None,a,b).get_grouped_opcodes(n):
@@ -1293,22 +1294,70 @@ def context_diff(a, b, fromfile='', tofile='',
                     for line in b[j1:j2]:
                         yield prefix[tag] + line
 
+def _check_types(a, b, *args):
+    # Checking types is weird, but the alternative is garbled output when
+    # someone passes mixed bytes and str to {unified,context}_diff(). E.g.
+    # without this check, passing filenames as bytes results in output like
+    #   --- b'oldfile.txt'
+    #   +++ b'newfile.txt'
+    # because of how str.format() incorporates bytes objects.
+    if a and not isinstance(a[0], str):
+        raise TypeError('lines to compare must be str, not %s (%r)' %
+                        (type(a[0]).__name__, a[0]))
+    if b and not isinstance(b[0], str):
+        raise TypeError('lines to compare must be str, not %s (%r)' %
+                        (type(b[0]).__name__, b[0]))
+    for arg in args:
+        if not isinstance(arg, str):
+            raise TypeError('all arguments must be str, not: %r' % (arg,))
+
+def diff_bytes(dfunc, a, b, fromfile=b'', tofile=b'',
+               fromfiledate=b'', tofiledate=b'', n=3, lineterm=b'\n'):
+    r"""
+    Compare `a` and `b`, two sequences of lines represented as bytes rather
+    than str. This is a wrapper for `dfunc`, which is typically either
+    unified_diff() or context_diff(). Inputs are losslessly converted to
+    strings so that `dfunc` only has to worry about strings, and encoded
+    back to bytes on return. This is necessary to compare files with
+    unknown or inconsistent encoding. All other inputs (except `n`) must be
+    bytes rather than str.
+    """
+    def decode(s):
+        try:
+            return s.decode('ascii', 'surrogateescape')
+        except AttributeError as err:
+            msg = ('all arguments must be bytes, not %s (%r)' %
+                   (type(s).__name__, s))
+            raise TypeError(msg) from err
+    a = list(map(decode, a))
+    b = list(map(decode, b))
+    fromfile = decode(fromfile)
+    tofile = decode(tofile)
+    fromfiledate = decode(fromfiledate)
+    tofiledate = decode(tofiledate)
+    lineterm = decode(lineterm)
+
+    lines = dfunc(a, b, fromfile, tofile, fromfiledate, tofiledate, n, lineterm)
+    for line in lines:
+        yield line.encode('ascii', 'surrogateescape')
+
 def ndiff(a, b, linejunk=None, charjunk=IS_CHARACTER_JUNK):
     r"""
     Compare `a` and `b` (lists of strings); return a `Differ`-style delta.
 
     Optional keyword parameters `linejunk` and `charjunk` are for filter
-    functions (or None):
+    functions, or can be None:
 
-    - linejunk: A function that should accept a single string argument, and
+    - linejunk: A function that should accept a single string argument and
       return true iff the string is junk.  The default is None, and is
-      recommended; as of Python 2.3, an adaptive notion of "noise" lines is
-      used that does a good job on its own.
+      recommended; the underlying SequenceMatcher class has an adaptive
+      notion of "noise" lines.
 
-    - charjunk: A function that should accept a string of length 1. The
-      default is module-level function IS_CHARACTER_JUNK, which filters out
-      whitespace characters (a blank or tab; note: bad idea to include newline
-      in this!).
+    - charjunk: A function that accepts a character (string of length
+      1), and returns true iff the character is junk. The default is
+      the module-level function IS_CHARACTER_JUNK, which filters out
+      whitespace characters (a blank or tab; note: it's a bad idea to
+      include newline in this!).
 
     Tools/scripts/ndiff.py is a command-line front-end to this function.
 
@@ -1410,7 +1459,7 @@ def _mdiff(fromlines, tolines, context=None, linejunk=None,
             change_re.sub(record_sub_info,markers)
             # process each tuple inserting our special marks that won't be
             # noticed by an xml/html escaper.
-            for key,(begin,end) in sub_info[::-1]:
+            for key,(begin,end) in reversed(sub_info):
                 text = text[0:begin]+'\0'+key+text[begin:end]+'\1'+text[end:]
             text = text[2:]
         # Handle case of add/delete entire line
@@ -1448,10 +1497,7 @@ def _mdiff(fromlines, tolines, context=None, linejunk=None,
             # are a concatenation of the first character of each of the 4 lines
             # so we can do some very readable comparisons.
             while len(lines) < 4:
-                try:
-                    lines.append(next(diff_lines_iterator))
-                except StopIteration:
-                    lines.append('X')
+                lines.append(next(diff_lines_iterator, 'X'))
             s = ''.join([line[0] for line in lines])
             if s.startswith('X'):
                 # When no more lines, pump out any remaining blank lines so the
@@ -1514,7 +1560,7 @@ def _mdiff(fromlines, tolines, context=None, linejunk=None,
                 num_blanks_to_yield -= 1
                 yield ('','\n'),None,True
             if s.startswith('X'):
-                raise StopIteration
+                return
             else:
                 yield from_line,to_line,True
 
@@ -1601,7 +1647,7 @@ _file_template = """
 
 <head>
     <meta http-equiv="Content-Type"
-          content="text/html; charset=ISO-8859-1" />
+          content="text/html; charset=%(charset)s" />
     <title></title>
     <style type="text/css">%(styles)s
     </style>
@@ -1679,7 +1725,7 @@ class HtmlDiff(object):
         tabsize -- tab stop spacing, defaults to 8.
         wrapcolumn -- column number where lines are broken and wrapped,
             defaults to None where lines are not wrapped.
-        linejunk,charjunk -- keyword arguments passed into ndiff() (used to by
+        linejunk,charjunk -- keyword arguments passed into ndiff() (used by
             HtmlDiff() to generate the side by side HTML differences).  See
             ndiff() documentation for argument default values and descriptions.
         """
@@ -1688,8 +1734,8 @@ class HtmlDiff(object):
         self._linejunk = linejunk
         self._charjunk = charjunk
 
-    def make_file(self,fromlines,tolines,fromdesc='',todesc='',context=False,
-                  numlines=5):
+    def make_file(self, fromlines, tolines, fromdesc='', todesc='',
+                  context=False, numlines=5, *, charset='utf-8'):
         """Returns HTML file of side by side comparison with change highlights
 
         Arguments:
@@ -1704,13 +1750,16 @@ class HtmlDiff(object):
             When context is False, controls the number of lines to place
             the "next" link anchors before the next change (so click of
             "next" link jumps to just before the change).
+        charset -- charset of the HTML document
         """
 
-        return self._file_template % dict(
-            styles = self._styles,
-            legend = self._legend,
-            table = self.make_table(fromlines,tolines,fromdesc,todesc,
-                                    context=context,numlines=numlines))
+        return (self._file_template % dict(
+            styles=self._styles,
+            legend=self._legend,
+            table=self.make_table(fromlines, tolines, fromdesc, todesc,
+                                  context=context, numlines=numlines),
+            charset=charset
+        )).encode(charset, 'xmlcharrefreplace').decode(charset)
 
     def _tab_newline_replace(self,fromlines,tolines):
         """Returns from/to line lists with tabs expanded and newlines removed.
diff --git a/Lib/dis.py b/Lib/dis.py
index 81cbe7f..d215bc5 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -29,7 +29,7 @@ def _try_compile(source, name):
     return c
 
 def dis(x=None, *, file=None):
-    """Disassemble classes, methods, functions, or code.
+    """Disassemble classes, methods, functions, generators, or code.
 
     With no argument, disassemble the last traceback.
 
@@ -41,6 +41,8 @@ def dis(x=None, *, file=None):
         x = x.__func__
     if hasattr(x, '__code__'):  # Function
         x = x.__code__
+    if hasattr(x, 'gi_code'):  # Generator
+        x = x.gi_code
     if hasattr(x, '__dict__'):  # Class or module
         items = sorted(x.__dict__.items())
         for name, x1 in items:
@@ -99,11 +101,13 @@ def pretty_flags(flags):
     return ", ".join(names)
 
 def _get_code_object(x):
-    """Helper to handle methods, functions, strings and raw code objects"""
+    """Helper to handle methods, functions, generators, strings and raw code objects"""
     if hasattr(x, '__func__'): # Method
         x = x.__func__
     if hasattr(x, '__code__'): # Function
         x = x.__code__
+    if hasattr(x, 'gi_code'):  # Generator
+        x = x.gi_code
     if isinstance(x, str):     # Source code
         x = _try_compile(x, "<disassembly>")
     if hasattr(x, 'co_code'):  # Code object
diff --git a/Lib/distutils/__init__.py b/Lib/distutils/__init__.py
index 00a5859..37bfd5a 100644
--- a/Lib/distutils/__init__.py
+++ b/Lib/distutils/__init__.py
@@ -13,5 +13,5 @@ used from a setup script as
 # Updated automatically by the Python release process.
 #
 #--start constants--
-__version__ = "3.4.3"
+__version__ = "3.5.0a4"
 #--end constants--
diff --git a/Lib/distutils/command/build.py b/Lib/distutils/command/build.py
index cfc15cf..337dd0b 100644
--- a/Lib/distutils/command/build.py
+++ b/Lib/distutils/command/build.py
@@ -36,6 +36,8 @@ class build(Command):
          "(default: %s)" % get_platform()),
         ('compiler=', 'c',
          "specify the compiler type"),
+        ('parallel=', 'j',
+         "number of parallel build jobs"),
         ('debug', 'g',
          "compile extensions and libraries with debugging information"),
         ('force', 'f',
@@ -65,6 +67,7 @@ class build(Command):
         self.debug = None
         self.force = 0
         self.executable = None
+        self.parallel = None
 
     def finalize_options(self):
         if self.plat_name is None:
@@ -116,6 +119,12 @@ class build(Command):
         if self.executable is None:
             self.executable = os.path.normpath(sys.executable)
 
+        if isinstance(self.parallel, str):
+            try:
+                self.parallel = int(self.parallel)
+            except ValueError:
+                raise DistutilsOptionError("parallel should be an integer")
+
     def run(self):
         # Run all relevant sub-commands.  This will be some subset of:
         #  - build_py      - pure Python modules
diff --git a/Lib/distutils/command/build_ext.py b/Lib/distutils/command/build_ext.py
index acbe648..c5a3ce1 100644
--- a/Lib/distutils/command/build_ext.py
+++ b/Lib/distutils/command/build_ext.py
@@ -4,7 +4,10 @@ Implements the Distutils 'build_ext' command, for building extension
 modules (currently limited to C extensions, should accommodate C++
 extensions ASAP)."""
 
-import sys, os, re
+import contextlib
+import os
+import re
+import sys
 from distutils.core import Command
 from distutils.errors import *
 from distutils.sysconfig import customize_compiler, get_python_version
@@ -85,6 +88,8 @@ class build_ext(Command):
          "forcibly build everything (ignore file timestamps)"),
         ('compiler=', 'c',
          "specify the compiler type"),
+        ('parallel=', 'j',
+         "number of parallel build jobs"),
         ('swig-cpp', None,
          "make SWIG create C++ files (default is C)"),
         ('swig-opts=', None,
@@ -124,6 +129,7 @@ class build_ext(Command):
         self.swig_cpp = None
         self.swig_opts = None
         self.user = None
+        self.parallel = None
 
     def finalize_options(self):
         from distutils import sysconfig
@@ -134,6 +140,7 @@ class build_ext(Command):
                                    ('compiler', 'compiler'),
                                    ('debug', 'debug'),
                                    ('force', 'force'),
+                                   ('parallel', 'parallel'),
                                    ('plat_name', 'plat_name'),
                                    )
 
@@ -202,7 +209,7 @@ class build_ext(Command):
             if MSVC_VERSION >= 9:
                 # Use the .lib files for the correct architecture
                 if self.plat_name == 'win32':
-                    suffix = ''
+                    suffix = 'win32'
                 else:
                     # win-amd64 or win-ia64
                     suffix = self.plat_name[4:]
@@ -274,6 +281,12 @@ class build_ext(Command):
                 self.library_dirs.append(user_lib)
                 self.rpath.append(user_lib)
 
+        if isinstance(self.parallel, str):
+            try:
+                self.parallel = int(self.parallel)
+            except ValueError:
+                raise DistutilsOptionError("parallel should be an integer")
+
     def run(self):
         from distutils.ccompiler import new_compiler
 
@@ -442,15 +455,45 @@ class build_ext(Command):
     def build_extensions(self):
         # First, sanity-check the 'extensions' list
         self.check_extensions_list(self.extensions)
+        if self.parallel:
+            self._build_extensions_parallel()
+        else:
+            self._build_extensions_serial()
+
+    def _build_extensions_parallel(self):
+        workers = self.parallel
+        if self.parallel is True:
+            workers = os.cpu_count()  # may return None
+        try:
+            from concurrent.futures import ThreadPoolExecutor
+        except ImportError:
+            workers = None
+
+        if workers is None:
+            self._build_extensions_serial()
+            return
+
+        with ThreadPoolExecutor(max_workers=workers) as executor:
+            futures = [executor.submit(self.build_extension, ext)
+                       for ext in self.extensions]
+            for ext, fut in zip(self.extensions, futures):
+                with self._filter_build_errors(ext):
+                    fut.result()
 
+    def _build_extensions_serial(self):
         for ext in self.extensions:
-            try:
+            with self._filter_build_errors(ext):
                 self.build_extension(ext)
-            except (CCompilerError, DistutilsError, CompileError) as e:
-                if not ext.optional:
-                    raise
-                self.warn('building extension "%s" failed: %s' %
-                          (ext.name, e))
+
+    @contextlib.contextmanager
+    def _filter_build_errors(self, ext):
+        try:
+            yield
+        except (CCompilerError, DistutilsError, CompileError) as e:
+            if not ext.optional:
+                raise
+            self.warn('building extension "%s" failed: %s' %
+                      (ext.name, e))
 
     def build_extension(self, ext):
         sources = ext.sources
@@ -502,15 +545,8 @@ class build_ext(Command):
                                          extra_postargs=extra_args,
                                          depends=ext.depends)
 
-        # XXX -- this is a Vile HACK!
-        #
-        # The setup.py script for Python on Unix needs to be able to
-        # get this list so it can perform all the clean up needed to
-        # avoid keeping object files around when cleaning out a failed
-        # build of an extension module.  Since Distutils does not
-        # track dependencies, we have to get rid of intermediates to
-        # ensure all the intermediates will be properly re-built.
-        #
+        # XXX outdated variable, kept here in case third-part code
+        # needs it.
         self._built_objects = objects[:]
 
         # Now link the object files together into a "shared object" --
@@ -655,10 +691,7 @@ class build_ext(Command):
         """
         from distutils.sysconfig import get_config_var
         ext_path = ext_name.split('.')
-        # extensions in debug_mode are named 'module_d.pyd' under windows
         ext_suffix = get_config_var('EXT_SUFFIX')
-        if os.name == 'nt' and self.debug:
-            return os.path.join(*ext_path) + '_d' + ext_suffix
         return os.path.join(*ext_path) + ext_suffix
 
     def get_export_symbols(self, ext):
diff --git a/Lib/distutils/command/build_py.py b/Lib/distutils/command/build_py.py
index 9100b96..cf0ca57 100644
--- a/Lib/distutils/command/build_py.py
+++ b/Lib/distutils/command/build_py.py
@@ -314,10 +314,10 @@ class build_py (Command):
             if include_bytecode:
                 if self.compile:
                     outputs.append(importlib.util.cache_from_source(
-                        filename, debug_override=True))
+                        filename, optimization=''))
                 if self.optimize > 0:
                     outputs.append(importlib.util.cache_from_source(
-                        filename, debug_override=False))
+                        filename, optimization=self.optimize))
 
         outputs += [
             os.path.join(build_dir, filename)
diff --git a/Lib/distutils/command/install.py b/Lib/distutils/command/install.py
index d768dc5..67db007 100644
--- a/Lib/distutils/command/install.py
+++ b/Lib/distutils/command/install.py
@@ -51,7 +51,7 @@ if HAS_USER_SITE:
         'purelib': '$usersite',
         'platlib': '$usersite',
         'headers': '$userbase/Python$py_version_nodot/Include/$dist_name',
-        'scripts': '$userbase/Scripts',
+        'scripts': '$userbase/Python$py_version_nodot/Scripts',
         'data'   : '$userbase',
         }
 
diff --git a/Lib/distutils/command/install_lib.py b/Lib/distutils/command/install_lib.py
author	Albert Cheng <acheng@hdfgroup.org>	1999-01-27 04:08:32 (GMT)
committer	Albert Cheng <acheng@hdfgroup.org>	1999-01-27 04:08:32 (GMT)
commit	2df1f8344e833c8c64a66615bf0a4f18a5da1f96 (patch)
tree	e6ffd39560c311a20b9e4155f6e01fbe2da283ba /testpar
parent	f7cd022ac47731c1781dfc408a729e00bf15d338 (diff)
download	hdf5-2df1f8344e833c8c64a66615bf0a4f18a5da1f96.zip hdf5-2df1f8344e833c8c64a66615bf0a4f18a5da1f96.tar.gz hdf5-2df1f8344e833c8c64a66615bf0a4f18a5da1f96.tar.bz2