+++++++++++

Python News

+++++++++++

What's New in Python 3.3.0 Alpha 4?

===================================

*Release date: XX-XXX-2012*

Core and Builtins

-----------------

- Issue #14705: The PyArg_Parse() family of functions now support the 'p' format

unit, which accepts a "boolean predicate" argument. It converts any Python

value into an integer--0 if it is "false", and 1 otherwise.

Library

-------

- Issue #13989: Add support for text mode to gzip.open().

- Issue #14127: The os.stat() result object now provides three additional

fields: st_ctime_ns, st_mtime_ns, and st_atime_ns, providing those times as an

integer with nanosecond resolution. The functions os.utime(), os.lutimes(),

and os.futimes() now accept a new parameter, ns, which accepts mtime and atime

as integers with nanosecond resolution.

- Issue #14127 and #10148: shutil.copystat now preserves exact mtime and atime

on filesystems providing nanosecond resolution.

Tools/Demos

-----------

- Issue #14965: Bring Tools/parser/unparse.py support up to date with

the Python 3.3 Grammar.

What's New in Python 3.3.0 Alpha 3?

===================================

*Release date: 01-May-2012*

Core and Builtins

-----------------

- Issue #14699: Fix calling the classmethod descriptor directly.

- Issue #14433: Prevent msvcrt crash in interactive prompt when stdin is closed.

- Issue #14521: Make result of float('nan') and float('-nan') more consistent

across platforms.

- Issue #14646: __import__() sets __loader__ if the loader did not.

- Issue #14605: No longer have implicit entries in sys.meta_path. If

sys.meta_path is found to be empty, raise ImportWarning.

- Issue #14605: No longer have implicit entries in sys.path_hooks. If

sys.path_hooks is found to be empty, a warning will be raised. None is now

inserted into sys.path_importer_cache if no finder was discovered. This also

means imp.NullImporter is no longer implicitly used.

- Issue #13903: Implement PEP 412. Individual dictionary instances can now share

their keys with other dictionaries. Classes take advantage of this to share

their instance dictionary keys for improved memory and performance.

- Issue #11603 (again): Setting __repr__ to __str__ now raises a RuntimeError

when repr() or str() is called on such an object.

- Issue #14658: Fix binding a special method to a builtin implementation of a

special method with a different name.

- Issue #14630: Fix a memory access bug for instances of a subclass of int

with value 0.

- Issue #14339: Speed improvements to bin, oct and hex functions. Patch by

Serhiy Storchaka.

- Issue #14098: New functions PyErr_GetExcInfo and PyErr_SetExcInfo.

Patch by Stefan Behnel.

- Issue #14385: It is now possible to use a custom type for the __builtins__

namespace, instead of a dict. It can be used for sandboxing for example.

Raise also a NameError instead of ImportError if __build_class__ name if not

found in __builtins__.

- Issue #12599: Be more strict in accepting None compared to a false-like

object for importlib.util.module_for_loader and

importlib.machinery.PathFinder.

- Issue #14612: Fix jumping around with blocks by setting f_lineno.

- Issue #14592: Attempting a relative import w/o __package__ or __name__ set in

globals raises a KeyError.

- Issue #14607: Fix keyword-only arguments which started with ``__``.

- Issue #10854: The ImportError raised when an extension module on Windows

fails to import now uses the new path and name attributes from

Issue #1559549.

- Issue #13889: Check and (if necessary) set FPU control word before calling

any of the dtoa.c string <-> float conversion functions, on MSVC builds of

Python. This fixes issues when embedding Python in a Delphi app.

- __import__() now matches PEP 328 and documentation by defaulting 'index' to 0

instead of -1 and removing support for negative values.

- Issue #2377: Make importlib the implementation of __import__().

- Issue #1559549: ImportError now has 'name' and 'path' attributes that are set

using keyword arguments to its constructor. They are currently not set by

import as they are meant for use by importlib.

- Issue #14474: Save and restore exception state in thread.start_new_thread()

while writing error message if the thread leaves a unhandled exception.

- Issue #13019: Fix potential reference leaks in bytearray.extend(). Patch

by Suman Saha.

Library

-------

- Issue #13815: TarFile.extractfile() now returns io.BufferedReader objects.

- Issue #14371: Support bzip2 in zipfile module. Patch by Serhiy Storchaka.

- Issue #13183: Fix pdb skipping frames after hitting a breakpoint and running

step. Patch by Xavier de Gaye.

- Issue #14696: Fix parser module to understand 'nonlocal' declarations.

- Issue #10941: Fix imaplib.Internaldate2tuple to produce correct result near

the DST transition. Patch by Joe Peterson.

- Issue #9154: Fix parser module to understand function annotations.

- Issue #6085: In http.server.py SimpleHTTPServer.address_string returns the

client ip address instead client hostname. Patch by Charles-François Natali.

- Issue #14309: Deprecate time.clock(), use time.perf_counter() or

time.process_time() instead.

- Issue #14428: Implement the PEP 418. Add time.get_clock_info(),

time.perf_counter() and time.process_time() functions, and rename

time.steady() to time.monotonic().

- Issue #14646: importlib.util.module_for_loader() now sets __loader__ and

__package__ (when possible).

- Issue #14664: It is now possible to use @unittest.skip{If,Unless} on a

test class that doesn't inherit from TestCase (i.e. a mixin).

- Issue #4892: multiprocessing Connections can now be transferred over

multiprocessing Connections. Patch by Richard Oudkerk (sbt).

- Issue #14160: TarFile.extractfile() failed to resolve symbolic links when

the links were not located in an archive subdirectory.

- Issue #14638: pydoc now treats non-string __name__ values as if they

were missing, instead of raising an error.

- Issue #13684: Fix httplib tunnel issue of infinite loops for certain sites

which send EOF without trailing \r\n.

- Issue #14605: Add importlib.abc.FileLoader, importlib.machinery.(FileFinder,

SourceFileLoader, SourcelessFileLoader, ExtensionFileLoader).

- Issue #13959: imp.cache_from_source()/source_from_cache() now follow

os.path.join()/split() semantics for path manipulation instead of its prior,

custom semantics of caring the right-most path separator forward in path

joining.

- Issue #2193: Allow ":" character in Cookie NAME values.

- Issue #14629: tokenizer.detect_encoding will specify the filename in the

SyntaxError exception if found at readline.__self__.name.

- Issue #14629: Raise SyntaxError in tokenizer.detect_encoding if the

first two lines have non-UTF-8 characters without an encoding declaration.

- Issue #14308: Fix an exception when a "dummy" thread is in the threading

module's active list after a fork().

- Issue #11750: The Windows API functions scattered in the _subprocess and

_multiprocessing.win32 modules now live in a single module "_winapi".

Patch by sbt.

- Issue #14087: multiprocessing: add Condition.wait_for(). Patch by sbt.

- Issue #14538: HTMLParser can now parse correctly start tags that contain

a bare '/'.

- Issue #14452: SysLogHandler no longer inserts a UTF-8 BOM into the message.

- Issue #14386: Expose the dict_proxy internal type as types.MappingProxyType.

- Issue #13959: Make imp.reload() always use a module's __loader__ to perform

the reload.

- Issue #13959: Add imp.py and rename the built-in module to _imp, allowing for

re-implementing parts of the module in pure Python.

- Issue #13496: Fix potential overflow in bisect.bisect algorithm when applied

to a collection of size > sys.maxsize / 2.

- Have importlib take advantage of ImportError's new 'name' and 'path'

attributes.

- Issue #14399: zipfile now recognizes that the archive has been modified even

if only the comment is changed. In addition, the TypeError that results from

trying to set a non-binary value as a comment is now now raised at the time

the comment is set rather than at the time the zipfile is written.

- trace.CoverageResults.is_ignored_filename() now ignores any name that starts

with "<" and ends with ">" instead of special-casing "<string>" and

"<doctest ".

- Issue #12537: The mailbox module no longer depends on knowledge of internal

implementation details of the email package Message object.

- Issue #7978: socketserver now restarts the select() call when EINTR is

returned. This avoids crashing the server loop when a signal is received.

Patch by Jerzy Kozera.

- Issue #14522: Avoid duplicating socket handles in multiprocessing.connection.

Patch by sbt.

- Don't Py_DECREF NULL variable in io.IncrementalNewlineDecoder.

- Issue #8515: Set __file__ when run file in IDLE.

Initial patch by Bruce Frederiksen.

- Issue #14496: Fix wrong name in idlelib/tabbedpages.py.

Patch by Popa Claudiu.

- Issue #3033: Add displayof parameter to tkinter font. Patch by Guilherme Polo.

- Issue #14482: Raise a ValueError, not a NameError, when trying to create

a multiprocessing Client or Listener with an AF_UNIX type address under

Windows. Patch by Popa Claudiu.

- Issue #802310: Generate always unique tkinter font names if not directly passed.

- Issue #14151: Raise a ValueError, not a NameError, when trying to create

a multiprocessing Client or Listener with an AF_PIPE type address under

non-Windows platforms. Patch by Popa Claudiu.

- Issue #14493: Use gvfs-open or xdg-open in webbrowser.

Build

-----

- "make touch" will now touch generated files that are checked into Mercurial,

after a "hg update" which failed to bring the timestamps into the right order.

Tests

-----

- Issue #14026: In test_cmd_line_script, check that sys.argv is populated

correctly for the various invocation approaches (Patch by Jason Yeo)

- Issue #14032: Fix incorrect variable name in test_cmd_line_script debugging

message (Patch by Jason Yeo)

- Issue #14589: Update certificate chain for sha256.tbs-internet.com, fixing

a test failure in test_ssl.

- Issue #14355: Regrtest now supports the standard unittest test loading, and

will use it if a test file contains no `test_main` method.

Tools / Demos

-------------

- Issue #3561: The Windows installer now has an option, off by default, for

placing the Python installation into the system "Path" environment variable.

- Issue #13165: stringbench is now available in the Tools/stringbench folder.

It used to live in its own SVN project.

What's New in Python 3.3.0 Alpha 2?

===================================

*Release date: 01-Apr-2012*

Core and Builtins

-----------------

- Issue #1683368: object.__new__ and object.__init__ raise a TypeError if they

are passed arguments and their complementary method is not overridden.

- Issue #14378: Fix compiling ast.ImportFrom nodes with a "__future__" string as

the module name that was not interned.

- Issue #14331: Use significantly less stack space when importing modules by

allocating path buffers on the heap instead of the stack.

- Issue #14334: Prevent in a segfault in type.__getattribute__ when it was not

passed strings.

- Issue #1469629: Allow cycles through an object's __dict__ slot to be

collected. (For example if ``x.__dict__ is x``).

- Issue #14205: dict lookup raises a RuntimeError if the dict is modified

during a lookup.

- Issue #14220: When a generator is delegating to another iterator with the

yield from syntax, it needs to have its ``gi_running`` flag set to True.

- Issue #14435: Remove dedicated block allocator from floatobject.c and rely

on the PyObject_Malloc() api like all other objects.

- Issue #14471: Fix a possible buffer overrun in the winreg module.

- Issue #14288: Allow the serialization of builtin iterators

Library

-------

- Issue #14300: Under Windows, sockets created using socket.dup() now allow

overlapped I/O. Patch by sbt.

- Issue #13872: socket.detach() now marks the socket closed (as mirrored

in the socket repr()). Patch by Matt Joiner.

- Issue #14406: Fix a race condition when using ``concurrent.futures.wait(

return_when=ALL_COMPLETED)``. Patch by Matt Joiner.

- Issue #5136: deprecate old, unused functions from tkinter.

- Issue #14409: IDLE now properly executes commands in the Shell window

when it cannot read the normal config files on startup and

has to use the built-in default key bindings.

There was previously a bug in one of the defaults.

- Issue #14416: syslog now defines the LOG_ODELAY and LOG_AUTHPRIV constants

if they are defined in <syslog.h>.

- IDLE can be launched as python -m idlelib

- Issue #14295: Add unittest.mock

- Issue #7652: Add --with-system-libmpdec option to configure for linking

the _decimal module against an installed libmpdec.

- Issue #14380: MIMEText now defaults to utf-8 when passed non-ASCII unicode

with no charset specified.

- Issue #10340: asyncore - properly handle EINVAL in dispatcher constructor on

OSX; avoid to call handle_connect in case of a disconnected socket which

was not meant to connect.

- Issue #14204: The ssl module now has support for the Next Protocol

Negotiation extension, if available in the underlying OpenSSL library.

Patch by Colin Marc.

- Issue #3035: Unused functions from tkinter are marked as pending deprecated.

- Issue #12757: Fix the skipping of doctests when python is run with -OO so

that it works in unittest's verbose mode as well as non-verbose mode.

- Issue #7652: Integrate the decimal floating point libmpdec library to speed

up the decimal module. Performance gains of the new C implementation are

between 10x and 100x, depending on the application.

- Issue #3573: IDLE hangs when passing invalid command line args

(directory(ies) instead of file(s)) (Patch by Guilherme Polo)

- Issue #14269: SMTPD now conforms to the RFC and requires a HELO command

before MAIL, RCPT, or DATA.

- Issue #13694: asynchronous connect in asyncore.dispatcher does not set addr

attribute.

- Issue #14344: fixed the repr of email.policy objects.

- Issue #11686: Added missing entries to email package __all__ lists

(mostly the new Bytes classes).

- Issue #14335: multiprocessing's custom Pickler subclass now inherits from

the C-accelerated implementation. Patch by sbt.

- Issue #10484: Fix the CGIHTTPServer's PATH_INFO handling problem.

- Issue #11199: Fix the with urllib which hangs on particular ftp urls.

- Improve the memory utilization and speed of functools.lru_cache.

- Issue #14222: Use the new time.steady() function instead of time.time() for

timeout in queue and threading modules to not be affected of system time

update.

- Issue #13248: Remove lib2to3.pytree.Base.get_prefix/set_prefix.

- Issue #14234: CVE-2012-0876: Randomize hashes of xml attributes in the hash

table internal to the pyexpat module's copy of the expat library to avoid a

denial of service due to hash collisions. Patch by David Malcolm with some

modifications by the expat project.

- Issue #14200: Idle shell crash on printing non-BMP unicode character.

- Issue #12818: format address no longer needlessly \ escapes ()s in names when

the name ends up being quoted.

- Issue #14062: BytesGenerator now correctly folds Header objects,

including using linesep when folding.

- Issue #13839: When invoked on the command-line, the pstats module now

accepts several filenames of profile stat files and merges them all.

Patch by Matt Joiner.

- Issue #14291: Email now defaults to utf-8 for non-ASCII unicode headers

instead of raising an error. This fixes a regression relative to 2.7.

- Issue #989712: Support using Tk without a mainloop.

- Issue #5219: Prevent event handler cascade in IDLE.

- Issue #3835: Refuse to use unthreaded Tcl in threaded Python.

- Issue #2843: Add new Tk API to Tkinter.

- Issue #14184: Increase the default stack size for secondary threads on

Mac OS X to avoid interpreter crashes when using threads on 10.7.

- Issue #14180: datetime.date.fromtimestamp(),

datetime.datetime.fromtimestamp() and datetime.datetime.utcfromtimestamp()

now raise an OSError instead of ValueError if localtime() or gmtime() failed.

- Issue #14180: time.ctime(), gmtime(), time.localtime(),

datetime.date.fromtimestamp(), datetime.datetime.fromtimestamp() and

datetime.datetime.utcfromtimestamp() now raises an OverflowError, instead of

a ValueError, if the timestamp does not fit in time_t.

- Issue #14180: datetime.datetime.fromtimestamp() and

datetime.datetime.utcfromtimestamp() now round microseconds towards zero

instead of rounding to nearest with ties going away from zero.

- Issue #10543: Fix unittest test discovery with Jython bytecode files.

- Issue #1178863: Separate initialisation from setting when initializing

Tkinter.Variables; harmonize exceptions to ValueError; only delete variables

that have not been deleted; assert that variable names are strings.

- Issue #14104: Implement time.monotonic() on Mac OS X, patch written by

Nicholas Riley.

- Issue #13394: the aifc module now uses warnings.warn() to signal warnings.

- Issue #14252: Fix subprocess.Popen.terminate() to not raise an error under

Windows when the child process has already exited.

- Issue #14223: curses.addch() is no more limited to the range 0-255 when the

Python curses is not linked to libncursesw. It was a regression introduced

in Python 3.3a1.

- Issue #14168: Check for presence of Element._attrs in minidom before

accessing it.

- Issue #12328: Fix multiprocessing's use of overlapped I/O on Windows.

Also, add a multiprocessing.connection.wait(rlist, timeout=None) function

for polling multiple objects at once. Patch by sbt.

- Issue #14007: Accept incomplete TreeBuilder objects (missing start, end,

data or close method) for the Python implementation as well.

Drop the no-op TreeBuilder().xml() method from the C implementation.

- Issue #14210: pdb now has tab-completion not only for command names, but

also for their arguments, wherever possible.

- Issue #14310: Sockets can now be with other processes on Windows using

the api socket.socket.share() and socket.fromshare().

- Issue #10576: The gc module now has a 'callbacks' member that will get

called when garbage collection takes place.

Build

-----

- Issue #14557: Fix extensions build on HP-UX. Patch by Adi Roiban.

- Issue #14387: Do not include accu.h from Python.h.

- Issue #14359: Only use O_CLOEXEC in _posixmodule.c if it is defined.

Based on patch from Hervé Coatanhay.

- Issue #14321: Do not run pgen during the build if files are up to date.

Documentation

-------------

- Issue #14034: added the argparse tutorial.

- Issue #14324: Fix configure tests for cross builds.

- Issue #14327: Call AC_CANONICAL_HOST in configure.ac and check in

config.{guess,sub}. Don't use uname calls for cross builds.

Extension Modules

-----------------

- Issue #14212: The re module didn't retain a reference to buffers it was

scanning, resulting in segfaults.

- Issue #14259: The finditer() method of re objects did not take any

keyword arguments, contrary to the documentation.

Tests

-----

- Issue #14442: Add missing errno import in test_smtplib.

- Issue #8315: (partial fix) python -m unittest test.test_email now works.

What's New in Python 3.3.0 Alpha 1?

===================================

*Release date: 05-Mar-2012*

Core and Builtins

-----------------

- Issue #14172: Fix reference leak when marshalling a buffer-like object

(other than a bytes object).

- Issue #13521: dict.setdefault() now does only one lookup for the given key,

making it "atomic" for many purposes. Patch by Filip Gruszczyński.

- PEP 409, Issue #6210: "raise X from None" is now supported as a means of

suppressing the display of the chained exception context. The chained

context still remains available as the __context__ attribute.

- Issue #10181: New memoryview implementation fixes multiple ownership

and lifetime issues of dynamically allocated Py_buffer members (#9990)

as well as crashes (#8305, #7433). Many new features have been added

(See whatsnew/3.3), and the documentation has been updated extensively.

The ndarray test object from _testbuffer.c implements all aspects of

PEP-3118, so further development towards the complete implementation

of the PEP can proceed in a test-driven manner.

Thanks to Nick Coghlan, Antoine Pitrou and Pauli Virtanen for review

and many ideas.

- Issue #12834: Fix incorrect results of memoryview.tobytes() for

non-contiguous arrays.

- Issue #5231: Introduce memoryview.cast() method that allows changing

format and shape without making a copy of the underlying memory.

- Issue #14084: Fix a file descriptor leak when importing a module with a

bad encoding.

- Upgrade Unicode data to Unicode 6.1.

- Issue #14040: Remove rarely used file name suffixes for C extensions

(under POSIX mainly).

- Issue #14051: Allow arbitrary attributes to be set of classmethod and

staticmethod.

- Issue #13703: oCERT-2011-003: Randomize hashes of str and bytes to protect

against denial of service attacks due to hash collisions within the dict and

set types. Patch by David Malcolm, based on work by Victor Stinner.

- Issue #13020: Fix a reference leak when allocating a structsequence object

fails. Patch by Suman Saha.

- Issue #13908: Ready types returned from PyType_FromSpec.

- Issue #11235: Fix OverflowError when trying to import a source file whose

modification time doesn't fit in a 32-bit timestamp.

- Issue #12705: A SyntaxError exception is now raised when attempting to

compile multiple statements as a single interactive statement.

- Fix the builtin module initialization code to store the init function for

future reinitialization.

- Issue #8052: The posix subprocess module would take a long time closing

all possible file descriptors in the child process rather than just open

file descriptors. It now closes only the open fds if possible for the

default close_fds=True behavior.

- Issue #13629: Renumber the tokens in token.h so that they match the indexes

into _PyParser_TokenNames.

- Issue #13752: Add a casefold() method to str.

- Issue #13761: Add a "flush" keyword argument to the print() function,

used to ensure flushing the output stream.

- Issue #13645: pyc files now contain the size of the corresponding source

code, to avoid timestamp collisions (especially on filesystems with a low

timestamp resolution) when checking for freshness of the bytecode.

- PEP 380, Issue #11682: Add "yield from <x>" to support easy delegation to

subgenerators (initial patch by Greg Ewing, integration into 3.3 by

Renaud Blanch, Ryan Kelly, Zbigniew Jędrzejewski-Szmek and Nick Coghlan)

- Issue #13748: Raw bytes literals can now be written with the ``rb`` prefix

as well as ``br``.

- Issue #12736: Use full unicode case mappings for upper, lower, and title case.

- Issue #12760: Add a create mode to open(). Patch by David Townshend.

- Issue #13738: Simplify implementation of bytes.lower() and bytes.upper().

- Issue #13577: Built-in methods and functions now have a __qualname__.

Patch by sbt.

- Issue #6695: Full garbage collection runs now clear the freelist of set

objects. Initial patch by Matthias Troffaes.

- Fix OSError.__init__ and OSError.__new__ so that each of them can be

overriden and take additional arguments (followup to issue #12555).

- Fix the fix for issue #12149: it was incorrect, although it had the side

effect of appearing to resolve the issue. Thanks to Mark Shannon for

noticing.

- Issue #13505: Pickle bytes objects in a way that is compatible with

Python 2 when using protocols <= 2.

- Issue #11147: Fix an unused argument in _Py_ANNOTATE_MEMORY_ORDER. (Fix

given by Campbell Barton).

- Issue #13503: Use a more efficient reduction format for bytearrays with

pickle protocol >= 3. The old reduction format is kept with older protocols

in order to allow unpickling under Python 2. Patch by Irmen de Jong.

- Issue #7111: Python can now be run without a stdin, stdout or stderr

stream. It was already the case with Python 2. However, the corresponding

sys module entries are now set to None (instead of an unusable file object).

- Issue #11849: Ensure that free()d memory arenas are really released

on POSIX systems supporting anonymous memory mappings. Patch by

Charles-François Natali.

- Issue #13452: PyUnicode_EncodeDecimal() doesn't support error handlers

different than "strict" anymore. The caller was unable to compute the

size of the output buffer: it depends on the error handler.

- PEP 3155 / issue #13448: Qualified name for classes and functions.

- Issue #13436: Fix a bogus error message when an AST object was passed

an invalid integer value.

- Issue #13411: memoryview objects are now hashable when the underlying

object is hashable.

- Issue #13338: Handle all enumerations in _Py_ANNOTATE_MEMORY_ORDER

to allow compiling extension modules with -Wswitch-enum on gcc.

Initial patch by Floris Bruynooghe.

- Issue #10227: Add an allocation cache for a single slice object. Patch by

Stefan Behnel.

- Issue #13393: BufferedReader.read1() now asks the full requested size to

the raw stream instead of limiting itself to the buffer size.

- Issue #13392: Writing a pyc file should now be atomic under Windows as well.

- Issue #13333: The UTF-7 decoder now accepts lone surrogates (the encoder

already accepts them).

- Issue #13389: Full garbage collection passes now clear the freelists for

list and dict objects. They already cleared other freelists in the

interpreter.

- Issue #13327: Remove the need for an explicit None as the second argument

to os.utime, os.lutimes, os.futimes, os.futimens, os.futimesat, in

order to update to the current time. Also added keyword argument

handling to os.utimensat in order to remove the need for explicit None.

- Issue #13350: Simplify some C code by replacing most usages of

PyUnicode_Format by PyUnicode_FromFormat.

- Issue #13342: input() used to ignore sys.stdin's and sys.stdout's unicode

error handler in interactive mode (when calling into PyOS_Readline()).

- Issue #9896: Add start, stop, and step attributes to range objects.

- Issue #13343: Fix a SystemError when a lambda expression uses a global

variable in the default value of a keyword-only argument: ``lambda *,

arg=GLOBAL_NAME: None``

- Issue #12797: Added custom opener parameter to builtin open() and

FileIO.open().

- Issue #10519: Avoid unnecessary recursive function calls in

setobject.c.

- Issue #10363: Deallocate global locks in Py_Finalize().

- Issue #13018: Fix reference leaks in error paths in dictobject.c.

Patch by Suman Saha.

- Issue #13201: Define '==' and '!=' to compare range objects based on

the sequence of values they define (instead of comparing based on

object identity).

- Issue #1294232: In a few cases involving metaclass inheritance, the

interpreter would sometimes invoke the wrong metaclass when building a new

class object. These cases now behave correctly. Patch by Daniel Urban.

- Issue #12753: Add support for Unicode name aliases and named sequences.

Both ``unicodedata.lookup()`` and '\N{...}' now resolve aliases,

and ``unicodedata.lookup()`` resolves named sequences too.

- Issue #12170: The count(), find(), rfind(), index() and rindex() methods

of bytes and bytearray objects now accept an integer between 0 and 255

as their first argument. Patch by Petri Lehtinen.

- Issue #12604: VTRACE macro expanded to no-op in _sre.c to avoid compiler

warnings. Patch by Josh Triplett and Petri Lehtinen.

- Issue #12281: Rewrite the MBCS codec to handle correctly replace and ignore

error handlers on all Windows versions. The MBCS codec is now supporting all

error handlers, instead of only replace to encode and ignore to decode.

- Issue #13188: When called without an explicit traceback argument,

generator.throw() now gets the traceback from the passed exception's

``__traceback__`` attribute. Patch by Petri Lehtinen.

- Issue #13146: Writing a pyc file is now atomic under POSIX.

- Issue #7833: Extension modules built using distutils on Windows will no

longer include a "manifest" to prevent them failing at import time in some

embedded situations.

- PEP 3151 / issue #12555: reworking the OS and IO exception hierarchy.

- Add internal API for static strings (_Py_identifier et al.).

- Issue #13063: the Windows error ERROR_NO_DATA (numbered 232 and described

as "The pipe is being closed") is now mapped to POSIX errno EPIPE

(previously EINVAL).

- Issue #12911: Fix memory consumption when calculating the repr() of huge

tuples or lists.

- PEP 393: flexible string representation. Thanks to Torsten Becker for the

initial implementation, and Victor Stinner for various bug fixes.

- Issue #14081: The 'sep' and 'maxsplit' parameter to str.split, bytes.split,

and bytearray.split may now be passed as keyword arguments.

- Issue #13012: The 'keepends' parameter to str.splitlines may now be passed

as a keyword argument: "my_string.splitlines(keepends=True)". The same

change also applies to bytes.splitlines and bytearray.splitlines.

- Issue #7732: Don't open a directory as a file anymore while importing a

module. Ignore the direcotry if its name matchs the module name (e.g.

"__init__.py") and raise a ImportError instead.

- Issue #13021: Missing decref on an error path. Thanks to Suman Saha for

finding the bug and providing a patch.

- Issue #12973: Fix overflow checks that relied on undefined behaviour in

list_repeat (listobject.c) and islice_next (itertoolsmodule.c). These bugs

caused test failures with recent versions of Clang.

- Issue #12904: os.utime, os.futimes, os.lutimes, and os.futimesat now write

atime and mtime with nanosecond precision on modern POSIX platforms.

- Issue #12802: the Windows error ERROR_DIRECTORY (numbered 267) is now

mapped to POSIX errno ENOTDIR (previously EINVAL).

- Issue #9200: The str.is* methods now work with strings that contain non-BMP

characters even in narrow Unicode builds.

- Issue #12791: Break reference cycles early when a generator exits with

an exception.

- Issue #12773: Make __doc__ mutable on user-defined classes.

- Issue #12766: Raise a ValueError when creating a class with a class variable

that conflicts with a name in __slots__.

- Issue #12266: Fix str.capitalize() to correctly uppercase/lowercase

titlecased and cased non-letter characters.

- Issue #12732: In narrow unicode builds, allow Unicode identifiers which fall

outside the BMP.

- Issue #12575: Validate user-generated AST before it is compiled.

- Make type(None), type(Ellipsis), and type(NotImplemented) callable. They

return the respective singleton instances.

- Forbid summing bytes with sum().

- Verify the types of AST strings and identifiers provided by the user before

compiling them.

- Issue #12647: The None object now has a __bool__() method that returns False.

Formerly, bool(None) returned False only because of special case logic

in PyObject_IsTrue().

- Issue #12579: str.format_map() now raises a ValueError if used on a

format string that contains positional fields. Initial patch by

Julian Berman.

- Issue #10271: Allow warnings.showwarning() be any callable.

- Issue #11627: Fix segfault when __new__ on a exception returns a

non-exception class.

- Issue #12149: Update the method cache after a type's dictionary gets

cleared by the garbage collector. This fixes a segfault when an instance

and its type get caught in a reference cycle, and the instance's

deallocator calls one of the methods on the type (e.g. when subclassing

IOBase). Diagnosis and patch by Davide Rizzo.

- Issue #9611, #9015: FileIO.read() clamps the length to INT_MAX on Windows.

- Issue #9642: Uniformize the tests on the availability of the mbcs codec, add

a new HAVE_MBCS define.

- Issue #9642: Fix filesystem encoding initialization: use the ANSI code page

on Windows if the mbcs codec is not available, and fail with a fatal error if

we cannot get the locale encoding (if nl_langinfo(CODESET) is not available)

instead of using UTF-8.

- When a generator yields, do not retain the caller's exception state on the

generator.

- Issue #12475: Prevent generators from leaking their exception state into the

caller's frame as they return for the last time.

- Issue #12291: You can now load multiple marshalled objects from a stream,

with other data interleaved between marshalled objects.

- Issue #12356: When required positional or keyword-only arguments are not

given, produce a informative error message which includes the name(s) of the

missing arguments.

- Issue #12370: Fix super with no arguments when __class__ is overriden in the

class body.

- Issue #12084: os.stat on Windows now works properly with relative symbolic

links when called from any directory.

- Loosen type restrictions on the __dir__ method. __dir__ can now return any

sequence, which will be converted to a list and sorted by dir().

- Issue #12265: Make error messages produced by passing an invalid set of

arguments to a function more informative.

- Issue #12225: Still allow Python to build if Python is not in its hg repo or

mercurial is not installed.

- Issue #1195: my_fgets() now always clears errors before calling fgets(). Fix

the following case: sys.stdin.read() stopped with CTRL+d (end of file),

raw_input() interrupted by CTRL+c.

- Issue #12216: Allow unexpected EOF errors to happen on any line of the file.

- Issue #12199: The TryExcept and TryFinally and AST nodes have been unified

into a Try node.

- Issue #9670: Increase the default stack size for secondary threads on

Mac OS X and FreeBSD to reduce the chances of a crash instead of a

"maximum recursion depth" RuntimeError exception.

(patch by Ronald Oussoren)

- Issue #12106: The use of the multiple-with shorthand syntax is now reflected

in the AST.

- Issue #12190: Try to use the same filename object when compiling unmarshalling

a code objects in the same file.

- Issue #12166: Move implementations of dir() specialized for various types into

the __dir__() methods of those types.

- Issue #5715: In socketserver, close the server socket in the child process.

- Correct lookup of __dir__ on objects. Among other things, this causes errors

besides AttributeError found on lookup to be propagated.

- Issue #12060: Use sig_atomic_t type and volatile keyword in the signal

module. Patch written by Charles-François Natali.

- Issue #1746656: Added the if_nameindex, if_indextoname, if_nametoindex

methods to the socket module.

- Issue #12044: Fixed subprocess.Popen when used as a context manager to

wait for the process to end when exiting the context to avoid unintentionally

leaving zombie processes around.

- Issue #1195: Fix input() if it is interrupted by CTRL+d and then CTRL+c,

clear the end-of-file indicator after CTRL+d.

- Issue #1856: Avoid crashes and lockups when daemon threads run while the

interpreter is shutting down; instead, these threads are now killed when

they try to take the GIL.

- Issue #9756: When calling a method descriptor or a slot wrapper descriptor,

the check of the object type doesn't read the __class__ attribute anymore.

Fix a crash if a class override its __class__ attribute (e.g. a proxy of the

str type). Patch written by Andreas Stührk.

- Issue #10517: After fork(), reinitialize the TLS used by the PyGILState_*

APIs, to avoid a crash with the pthread implementation in RHEL 5. Patch

by Charles-François Natali.

- Issue #10914: Initialize correctly the filesystem codec when creating a new

subinterpreter to fix a bootstrap issue with codecs implemented in Python, as

the ISO-8859-15 codec.

- Issue #11918: OS/2 and VMS are no more supported because of the lack of

maintainer.

- Issue #6780: fix starts/endswith error message to mention that tuples are

accepted too.

- Issue #5057: fix a bug in the peepholer that led to non-portable pyc files

between narrow and wide builds while optimizing BINARY_SUBSCR on non-BMP

chars (e.g. "\U00012345"[0]).

- Issue #11845: Fix typo in rangeobject.c that caused a crash in

compute_slice_indices. Patch by Daniel Urban.

- Issue #5673: Added a `timeout` keyword argument to subprocess.Popen.wait,

subprocess.Popen.communicated, subprocess.call, subprocess.check_call, and

subprocess.check_output. If the blocking operation takes more than `timeout`

seconds, the `subprocess.TimeoutExpired` exception is raised.

- Issue #11650: PyOS_StdioReadline() retries fgets() if it was interrupted

(EINTR), for example if the program is stopped with CTRL+z on Mac OS X. Patch

written by Charles-Francois Natali.

- Issue #9319: Include the filename in "Non-UTF8 code ..." syntax error.

- Issue #10785: Store the filename as Unicode in the Python parser.

- Issue #11619: _PyImport_LoadDynamicModule() doesn't encode the path to bytes

on Windows.

- Issue #10998: Remove mentions of -Q, sys.flags.division_warning and

Py_DivisionWarningFlag left over from Python 2.

- Issue #11244: Remove an unnecessary peepholer check that was preventing

negative zeros from being constant-folded properly.

- Issue #11395: io.FileIO().write() clamps the data length to 32,767 bytes on

Windows if the file is a TTY to workaround a Windows bug. The Windows console

returns an error (12: not enough space error) on writing into stdout if

stdout mode is binary and the length is greater than 66,000 bytes (or less,

depending on heap usage).

- Issue #11320: fix bogus memory management in Modules/getpath.c, leading to

a possible crash when calling Py_SetPath().

- Issue #11432: A bug was introduced in subprocess.Popen on posix systems with

3.2.0 where the stdout or stderr file descriptor being the same as the stdin

file descriptor would raise an exception. webbrowser.open would fail. fixed.

- Issue #9856: Change object.__format__ with a non-empty format string

to be a DeprecationWarning. In 3.2 it was a PendingDeprecationWarning.

In 3.4 it will be a TypeError.

- Issue #11244: The peephole optimizer is now able to constant-fold

arbitrarily complex expressions. This also fixes a 3.2 regression where

operations involving negative numbers were not constant-folded.

- Issue #11450: Don't truncate hg version info in Py_GetBuildInfo() when

there are many tags (e.g. when using mq). Patch by Nadeem Vawda.

- Issue #11335: Fixed a memory leak in list.sort when the key function

throws an exception.

- Issue #8923: When a string is encoded to UTF-8 in strict mode, the result is

cached into the object. Examples: str.encode(), str.encode('utf-8'),

PyUnicode_AsUTF8String() and PyUnicode_AsEncodedString(unicode, "utf-8",

NULL).

- Issue #10831: PyUnicode_FromFormat() supports %li, %lli and %zi formats.

- Issue #10829: Refactor PyUnicode_FromFormat(), use the same function to parse

the format string in the 3 steps, fix crashs on invalid format strings.

- Issue #13007: whichdb should recognize gdbm 1.9 magic numbers.

- Issue #11246: Fix PyUnicode_FromFormat("%V") to decode the byte string from

UTF-8 (with replace error handler) instead of ISO-8859-1 (in strict mode).

Patch written by Ray Allen.

- Issue #11286: Raise a ValueError from calling PyMemoryView_FromBuffer with

a buffer struct having a NULL data pointer.

- Issue #11272: On Windows, input() strips '\r' (and not only '\n'), and

sys.stdin uses universal newline (replace '\r\n' by '\n').

- issue #11828: startswith and endswith don't accept None as slice index.

Patch by Torsten Becker.