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Diffstat (limited to 'Doc/whatsnew/2.7.rst')
| -rw-r--r-- | Doc/whatsnew/2.7.rst | 288 |
1 files changed, 229 insertions, 59 deletions
diff --git a/Doc/whatsnew/2.7.rst b/Doc/whatsnew/2.7.rst index 05fe385..e063f1b 100644 --- a/Doc/whatsnew/2.7.rst +++ b/Doc/whatsnew/2.7.rst @@ -222,11 +222,70 @@ module, but it's easier to use. :pep:`378` - Format Specifier for Thousands Separator PEP written by Raymond Hettinger; implemented by Eric Smith. +PEP 389: The argparse Module for Parsing Command Lines +====================================================== + +XXX write this section. + +.. seealso:: + + :pep:`389` - argparse - New Command Line Parsing Module + PEP written and implemented by Steven Bethard. + +PEP 391: Dictionary-Based Configuration For Logging +==================================================== + +XXX write this section. + +.. seealso:: + + :pep:`391` - Dictionary-Based Configuration For Logging + PEP written and implemented by Vinay Sajip. + +PEP 3106: Dictionary Views +==================================================== + +XXX write this section. + +.. seealso:: + + :pep:`3106` - Revamping dict.keys(), .values() and .items() + PEP written by Guido van Rossum. + Backported to 2.7 by Alexandre Vassalotti; :issue:`1967`. + + Other Language Changes ====================== Some smaller changes made to the core Python language are: +* The syntax for set literals has been backported from Python 3.x. + Curly brackets are used to surround the contents of the resulting + mutable set; set literals are + distinguished from dictionaries by not containing colons and values. + ``{}`` continues to represent an empty dictionary; use + ``set()`` for an empty set. + + >>> {1,2,3,4,5} + set([1, 2, 3, 4, 5]) + >>> set() + set([]) + >>> {} + {} + + Backported by Alexandre Vassalotti; :issue:`2335`. + +* Dictionary and set comprehensions are another feature backported from + 3.x, generalizing list/generator comprehensions to use + the literal syntax for sets and dictionaries. + + >>> {x:x*x for x in range(6)} + {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25} + >>> {'a'*x for x in range(6)} + set(['', 'a', 'aa', 'aaa', 'aaaa', 'aaaaa']) + + Backported by Alexandre Vassalotti; :issue:`2333`. + * The :keyword:`with` statement can now use multiple context managers in one statement. Context managers are processed from left to right and each one is treated as beginning a new :keyword:`with` statement. @@ -363,7 +422,10 @@ Some smaller changes made to the core Python language are: * The :class:`file` object will now set the :attr:`filename` attribute on the :exc:`IOError` exception when trying to open a directory - on POSIX platforms. (Noted by Jan Kaliszewski; :issue:`4764`.) + on POSIX platforms (noted by Jan Kaliszewski; :issue:`4764`), and + now explicitly checks for and forbids writing to read-only file objects + instead of trusting the C library to catch and report the error + (fixed by Stefan Krah; :issue:`5677`). * The Python tokenizer now translates line endings itself, so the :func:`compile` built-in function can now accept code using any @@ -375,6 +437,10 @@ Some smaller changes made to the core Python language are: Python3-warning mode, Python 2.7 will now warn about this odd usage. (Noted by James Lingard; :issue:`7362`.) +* When a module object is garbage-collected, the module's dictionary is + now only cleared if no one else is holding a reference to the + dictionary (:issue:`7140`). + .. ====================================================================== @@ -498,6 +564,10 @@ changes, or look through the Subversion logs for all the details. (Contributed by Maru Newby after a suggestion by Senthil Kumaran; :issue:`5142`.) +* The :mod:`binascii` module now supports the buffer API, so it can be + used with :class:`memoryview` instances and other similar buffer objects. + (Backported from 3.x by Florent Xicluna; :issue:`7703`.) + * The :mod:`bz2` module's :class:`BZ2File` now supports the context management protocol, so you can write ``with bz2.BZ2File(...) as f: ...``. (Contributed by Hagen Fuerstenau; :issue:`3860`.) @@ -566,7 +636,10 @@ changes, or look through the Subversion logs for all the details. * The :mod:`ctypes` module now always converts ``None`` to a C NULL pointer for arguments declared as pointers. (Changed by Thomas - Heller; :issue:`4606`.) + Heller; :issue:`4606`.) The underlying `libffi library + <http://sourceware.org/libffi/>`__ has been updated to version + 3.0.9, containing various fixes for different platforms. (Updated + by Matthias Klose; :issue:`8142`.) * New method: the :mod:`datetime` module's :class:`timedelta` class gained a :meth:`total_seconds` method that returns the number of seconds @@ -592,46 +665,6 @@ changes, or look through the Subversion logs for all the details. left-alignment. This has been changed to right-alignment, which seems more sensible for numeric types. (Changed by Mark Dickinson; :issue:`6857`.) -* Distutils is being more actively developed, thanks to Tarek Ziadé - who has taken over maintenance of the package, so there are a number - of fixes and improvments. - - A new :file:`setup.py` subcommand, ``check``, will check that the - arguments being passed to the :func:`setup` function are complete - and correct (:issue:`5732`). - - Byte-compilation by the ``install_lib`` subcommand is now only done - if the ``sys.dont_write_bytecode`` setting allows it (:issue:`7071`). - - :func:`distutils.sdist.add_defaults` now uses - *package_dir* and *data_files* to create the MANIFEST file. - :mod:`distutils.sysconfig` now reads the :envvar:`AR` and - :envvar:`ARFLAGS` environment variables. - - .. ARFLAGS done in #5941 - - It is no longer mandatory to store clear-text passwords in the - :file:`.pypirc` file when registering and uploading packages to PyPI. As long - as the username is present in that file, the :mod:`distutils` package will - prompt for the password if not present. (Added by Tarek Ziadé, - based on an initial contribution by Nathan Van Gheem; :issue:`4394`.) - - A Distutils setup can now specify that a C extension is optional by - setting the *optional* option setting to true. If this optional is - supplied, failure to build the extension will not abort the build - process, but instead simply not install the failing extension. - (Contributed by Georg Brandl; :issue:`5583`.) - - The :class:`distutils.dist.DistributionMetadata` class' - :meth:`read_pkg_file` method will read the contents of a package's - :file:`PKG-INFO` metadata file. For an example of its use, see - :ref:`reading-metadata`. - (Contributed by Tarek Ziadé; :issue:`7457`.) - - :file:`setup.py` files will now accept a :option:`--no-user-cfg` switch - to skip reading the :file:`~/.pydistutils.cfg` file. (Suggested by - by Michael Hoffman, and implemented by Paul Winkler; :issue:`1180`.) - * The :class:`Fraction` class now accepts two rational numbers as arguments to its constructor. (Implemented by Mark Dickinson; :issue:`5812`.) @@ -649,9 +682,12 @@ changes, or look through the Subversion logs for all the details. otherwise. (Contributed by Antoine Pitrou; :issue:`4688`.) * The :mod:`gzip` module's :class:`GzipFile` now supports the context - management protocol, so you can write ``with gzip.GzipFile(...) as f: ...``. - (Contributed by Hagen Fuerstenau; :issue:`3860`.) - It's now possible to override the modification time + management protocol, so you can write ``with gzip.GzipFile(...) as f: ...`` + (contributed by Hagen Fuerstenau; :issue:`3860`), and it now implements + the :class:`io.BufferedIOBase` ABC, so you can wrap it with + :class:`io.BufferedReader` for faster processing + (contributed by Nir Aides; :issue:`7471`). + It's also now possible to override the modification time recorded in a gzipped file by providing an optional timestamp to the constructor. (Contributed by Jacques Frechet; :issue:`4272`.) @@ -663,6 +699,11 @@ changes, or look through the Subversion logs for all the details. supports buffering, resulting in much faster reading of HTTP responses. (Contributed by Kristjan Valur Jonsson; :issue:`4879`.) + The :class:`HTTPConnection` and :class:`HTTPSConnection` classes + now support a *source_address* parameter, a ``(host, port)`` 2-tuple + giving the source address that will be used for the connection. + (Contributed by Eldon Ziegler; :issue:`3972`.) + * The :mod:`imaplib` module now supports IPv6 addresses. (Contributed by Derek Morr; :issue:`1655`.) @@ -756,6 +797,10 @@ changes, or look through the Subversion logs for all the details. contributed by Travis H.; :issue:`6508`. Support for initgroups added by Jean-Paul Calderone; :issue:`7333`.) + The :func:`os.fork` function now re-initializes the import lock in + the child process; this fixes problems on Solaris when :func:`fork` + is called from a thread. (Fixed by Zsolt Cserna; :issue:`7242`.) + The :func:`normpath` function now preserves Unicode; if its input path is a Unicode string, the return value is also a Unicode string. (Fixed by Matt Giuca; :issue:`5827`.) @@ -774,6 +819,10 @@ changes, or look through the Subversion logs for all the details. named pipes like a regular file by opening them for reading, and this would block indefinitely. (Fixed by Antoine Pitrou; :issue:`3002`.) + New function: :func:`make_archive` takes a filename, archive type + (zip or tar-format), and a directory path, and creates an archive + containing the directory's contents. (Added by Tarek Ziadé.) + * New functions: in the :mod:`site` module, three new functions return various site- and user-specific paths. :func:`getsitepackages` returns a list containing all @@ -785,9 +834,24 @@ changes, or look through the Subversion logs for all the details. to store data. (Contributed by Tarek Ziadé; :issue:`6693`.) + The :mod:`site` module now reports exceptions occurring + when the :mod:`sitecustomize` module is imported, and will no longer + catch and swallow the :exc:`KeyboardError` exception. (Fixed by + Victor Stinner; :issue:`3137`.) + * The :mod:`socket` module's :class:`SSL` objects now support the - buffer API, which fixed a test suite failure. (Fixed by Antoine Pitrou; - :issue:`7133`.) + buffer API, which fixed a test suite failure. (Fixed by Antoine + Pitrou; :issue:`7133`.) + + The :func:`create_connection` function + gained a *source_address* parameter, a ``(host, port)`` 2-tuple + giving the source address that will be used for the connection. + (Contributed by Eldon Ziegler; :issue:`3972`.) + + The :meth:`recv_into` and `recvfrom_into` methods will now write + into objects that support the buffer API, most usefully + the :class:`bytearray` and :class:`memoryview` objects. (Implemented by + Antoine Pitrou; :issue:`8104`.) * The :mod:`SocketServer` module's :class:`TCPServer` class now has a :attr:`disable_nagle_algorithm` class attribute. @@ -796,6 +860,13 @@ changes, or look through the Subversion logs for all the details. prevent buffering many small sends into a single TCP packet. (Contributed by Kristjan Valur Jonsson; :issue:`6192`.) +* Updated module: the :mod:`sqlite` module has been updated to + version 2.6.0 of the `pysqlite package <http://code.google.com/p/pysqlite/>`__. Version 2.6.0 includes a number of bugfixes, and adds + the ability to load SQLite extensions from shared libraries. + Call the ``enable_load_extension(True)`` method to enable extensions, + and then call :meth:`load_extension` to load a particular shared library. + (Updated by Gerhard Häring.) + * The :mod:`struct` module will no longer silently ignore overflow errors when a value is too large for a particular integer format code (one of ``bBhHiIlLqQ``); it now always raises a @@ -852,6 +923,8 @@ changes, or look through the Subversion logs for all the details. resulting archive. This is more powerful than the existing *exclude* argument, which has therefore been deprecated. (Added by Lars Gustäbel; :issue:`6856`.) + The :class:`TarFile` class also now supports the context manager protocol. + (Added by Lars Gustäbel; :issue:`7232`.) * The :mod:`threading` module's :meth:`Event.wait` method now returns the internal flag on exit. This means the method will usually @@ -860,9 +933,22 @@ changes, or look through the Subversion logs for all the details. a timeout was provided and the operation timed out. (Contributed by Tim Lesher; :issue:`1674032`.) +* The Unicode database provided by the :mod:`unicodedata` module + remains at version 5.1.0, but Python now uses it internally to + determine which characters are numeric, whitespace, or represent + line breaks. The database also now includes information from the + :file:`Unihan.txt` data file. (Patch by Anders Chrigström + and Amaury Forgeot d'Arc; :issue:`1571184`.) + * The :class:`UserDict` class is now a new-style class. (Changed by Benjamin Peterson.) +* The ElementTree library, :mod:`xml.etree`, no longer escapes + ampersands and angle brackets when outputting an XML processing + instruction (which looks like `<?xml-stylesheet href="#style1"?>`) + or comment (which looks like `<!-- comment -->`). + (Patch by Neil Muller; :issue:`2746`.) + * The :mod:`zipfile` module's :class:`ZipFile` now supports the context management protocol, so you can write ``with zipfile.ZipFile(...) as f: ...``. (Contributed by Brian Curtin; :issue:`5511`.) @@ -877,18 +963,81 @@ changes, or look through the Subversion logs for all the details. accepts a file object, in addition to the path names accepted in earlier versions. (Contributed by Gabriel Genellina; :issue:`4756`.) + The :meth:`writestr` method now has an optional *compress_type* parameter + that lets you override the default compression method specified in the + :class:`ZipFile` constructor. (Contributed by Ronald Oussoren; + :issue:`6003`.) + * XXX the :mod:`shutil` module has now a :func:`make_archive` function - (see the module doc, contributed by Tarek) + (see the module doc, contributed by Tarek) + + +New module: sysconfig +--------------------------------- + +XXX A new :mod:`sysconfig` module has been extracted from +:mod:`distutils` and put in the standard library. + +The :mod:`sysconfig` module provides access to Python's configuration +information like the list of installation paths and the configuration +variables relevant for the current platform. (contributed by Tarek) + +Updated module: ElementTree 1.3 +--------------------------------- + +XXX write this. .. ====================================================================== .. whole new modules get described in subsections here -* XXX A new :mod:`sysconfig` module has been extracted from :mod:`distutils` - and put in the standard library. - The :mod:`sysconfig` module provides access to Python's configuration - information like the list of installation paths and the configuration - variables relevant for the current platform. +Distutils Enhancements +--------------------------------- + +Distutils is being more actively developed, thanks to Tarek Ziadé +who has taken over maintenance of the package, so there are a number +of fixes and improvements. + +A new :file:`setup.py` subcommand, ``check``, will check that the +arguments being passed to the :func:`setup` function are complete +and correct (:issue:`5732`). + +Byte-compilation by the ``install_lib`` subcommand is now only done +if the ``sys.dont_write_bytecode`` setting allows it (:issue:`7071`). + +:func:`distutils.sdist.add_defaults` now uses +*package_dir* and *data_files* to create the MANIFEST file. +:mod:`distutils.sysconfig` now reads the :envvar:`AR` and +:envvar:`ARFLAGS` environment variables. + +.. ARFLAGS done in #5941 + +It is no longer mandatory to store clear-text passwords in the +:file:`.pypirc` file when registering and uploading packages to PyPI. As long +as the username is present in that file, the :mod:`distutils` package will +prompt for the password if not present. (Added by Tarek Ziadé, +based on an initial contribution by Nathan Van Gheem; :issue:`4394`.) + +A Distutils setup can now specify that a C extension is optional by +setting the *optional* option setting to true. If this optional is +supplied, failure to build the extension will not abort the build +process, but instead simply not install the failing extension. +(Contributed by Georg Brandl; :issue:`5583`.) + +The :class:`distutils.dist.DistributionMetadata` class' +:meth:`read_pkg_file` method will read the contents of a package's +:file:`PKG-INFO` metadata file. For an example of its use, see +:ref:`reading-metadata`. +(Contributed by Tarek Ziadé; :issue:`7457`.) + +:file:`setup.py` files will now accept a :option:`--no-user-cfg` switch +to skip reading the :file:`~/.pydistutils.cfg` file. (Suggested by +by Michael Hoffman, and implemented by Paul Winkler; :issue:`1180`.) + +When creating a tar-format archive, the ``sdist`` subcommand now +allows specifying the user id and group that will own the files in the +archives using the :option:`--owner` and :option:`--group` switches +(:issue:`6516`). Unit Testing Enhancements @@ -948,7 +1097,8 @@ GvR worked on merging them into Python's version of :mod:`unittest`. * :meth:`assertMultiLineEqual` compares two strings, and if they're not equal, displays a helpful comparison that highlights the - differences in the two strings. + differences in the two strings. This comparison is now used by + default when Unicode strings are compared with :meth:`assertEqual`.) * :meth:`assertRegexpMatches` checks whether its first argument is a string matching a regular expression provided as its second argument. @@ -967,18 +1117,22 @@ GvR worked on merging them into Python's version of :mod:`unittest`. only reports the differences between the sets in case of error. * Similarly, :meth:`assertListEqual` and :meth:`assertTupleEqual` - compare the specified types and explain the differences. + compare the specified types and explain any differences without necessarily + printing their full values; these methods are now used by default + when comparing lists and tuples using :meth:`assertEqual`. More generally, :meth:`assertSequenceEqual` compares two sequences and can optionally check whether both sequences are of a particular type. * :meth:`assertDictEqual` compares two dictionaries and reports the - differences. :meth:`assertDictContainsSubset` checks whether + differences; it's now used by default when you compare two dictionaries + using :meth:`assertEqual`. :meth:`assertDictContainsSubset` checks whether all of the key/value pairs in *first* are found in *second*. -* :meth:`assertAlmostEqual` and :meth:`assertNotAlmostEqual` short-circuit - (automatically pass or fail without checking decimal places) if the objects - are equal. +* :meth:`assertAlmostEqual` and :meth:`assertNotAlmostEqual` test + whether *first* and *second* are approximately equal by computing + their difference, rounding the result to an optionally-specified number + of *places* (the default is 7), and comparing to zero. * :meth:`loadTestsFromName` properly honors the ``suiteClass`` attribute of the :class:`TestLoader`. (Fixed by Mark Roddy; :issue:`6866`.) @@ -1232,6 +1386,14 @@ Port-Specific Changes: Mac OS X Other Changes and Fixes ======================= +* Two benchmark scripts, :file:`iobench` and :file:`ccbench`, were + added to the :file:`Tools` directory. :file:`iobench` measures the + speed of built-in file I/O objects (as returned by :func:`open`) + while performing various operations, and :file:`ccbench` is a + concurrency benchmark that tries to measure computing throughput, + thread switching latency, and IO processing bandwidth when + performing several tasks using a varying number of threads. + * When importing a module from a :file:`.pyc` or :file:`.pyo` file with an existing :file:`.py` counterpart, the :attr:`co_filename` attributes of the resulting code objects are overwritten when the @@ -1283,6 +1445,14 @@ that may require changes to your code: nothing when a negative length is requested, as other file-like objects do. (:issue:`7348`). +In the standard library: + +* The ElementTree library, :mod:`xml.etree`, no longer escapes + ampersands and angle brackets when outputting an XML processing + instruction (which looks like `<?xml-stylesheet href="#style1"?>`) + or comment (which looks like `<!-- comment -->`). + (Patch by Neil Muller; :issue:`2746`.) + For C extensions: * C extensions that use integer format codes with the ``PyArg_Parse*`` |