+++++++++++

Python News

+++++++++++

What's New in Python 3.3.1?

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

*Not yet released, see sections below for changes released in 3.3.0*

.. *Release date: XX-XXX-2012*

Core and Builtins

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

- Issue #14850: Now a chamap decoder treates U+FFFE as "undefined mapping"

in any mapping, not only in a string.

- Issue #16730: importlib.machinery.FileFinder now no longers raises an

exception when trying to populate its cache and it finds out the directory is

unreadable or has turned into a file. Reported and diagnosed by

David Pritchard.

- Issue #16906: Fix a logic error that prevented most static strings from being

cleared.

- Issue #11461: Fix the incremental UTF-16 decoder. Original patch by

Amaury Forgeot d'Arc.

- Issue #16881: Fix Py_ARRAY_LENGTH macro for GCC < 3.1.

- Issue #16856: Fix a segmentation fault from calling repr() on a dict with

a key whose repr raise an exception.

- Issue #16367: Fix FileIO.readall() on Windows for files larger than 2 GB.

- Issue #16455: On FreeBSD and Solaris, if the locale is C, the

ASCII/surrogateescape codec is now used, instead of the locale encoding, to

decode the command line arguments. This change fixes inconsistencies with

os.fsencode() and os.fsdecode() because these operating systems announces an

ASCII locale encoding, whereas the ISO-8859-1 encoding is used in practice.

- Issue #16761: Calling int() with base argument only now raises TypeError.

- Issue #16759: Support the full DWORD (unsigned long) range in Reg2Py

when retreiving a REG_DWORD value. This corrects functions like

winreg.QueryValueEx that may have been returning truncated values.

- Issue #14420: Support the full DWORD (unsigned long) range in Py2Reg

when passed a REG_DWORD value. Fixes OverflowError in winreg.SetValueEx.

- Issue #16597: In buffered and text IO, call close() on the underlying stream

if invoking flush() fails.

- Issue #16722: In the bytes() constructor, try to call __bytes__ on the

argument before __index__.

- Issue #16602: When a weakref's target was part of a long deallocation

chain, the object could remain reachable through its weakref even though

its refcount had dropped to zero.

- Issue #16416: On Mac OS X, operating system data are now always

encoded/decoded to/from UTF-8/surrogateescape, instead of the locale encoding

(which may be ASCII if no locale environment variable is set), to avoid

inconsistencies with os.fsencode() and os.fsdecode() functions which are

already using UTF-8/surrogateescape.

- Issue #16588: Silence unused-but-set warnings in Python/thread_pthread

- Issue #16546: Fix: ast.YieldFrom argument is now mandatory.

- Issue #16514: Fix regression causing a traceback when sys.path[0] is None

(actually, any non-string or non-bytes type).

- Issue #16306: Fix multiple error messages when unknown command line

parameters where passed to the interpreter. Patch by Hieu Nguyen.

- Issue #16215: Fix potential double memory free in str.replace(). Patch

by Serhiy Storchaka.

- Issue #16453: Fix equality testing of dead weakref objects.

- Issue #9535: Fix pending signals that have been received but not yet

handled by Python to not persist after os.fork() in the child process.

- Issue #15001: fix segfault on "del sys.modules['__main__']". Patch by Victor

Stinner.

- Issue #8271: the utf-8 decoder now outputs the correct number of U+FFFD

characters when used with the 'replace' error handler on invalid utf-8

sequences. Patch by Serhiy Storchaka, tests by Ezio Melotti.

- Issue #5765: Apply a hard recursion limit in the compiler instead of

blowing the stack and segfaulting. Initial patch by Andrea Griffini.

- Issue #16402: When slicing a range, fix shadowing of exceptions from

__index__.

- Issue #16336: fix input checking in the surrogatepass error handler.

Patch by Serhiy Storchaka.

- Issue #8401: assigning an int to a bytearray slice (e.g. b[3:4] = 5) now

raises an error.

- Fix segfaults on setting __qualname__ on builtin types and attempting to

delete it on any type.

- Issue #16345: Fix an infinite loop when ``fromkeys`` on a dict subclass

received a nonempty dict from the constructor.

- Issue #16271: Fix strange bugs that resulted from __qualname__ appearing in a

class's __dict__ and on type.

- Issue #16197: Update winreg docstrings and documentation to match code.

Patch by Zachary Ware.

- Issue #16241: Document -X faulthandler command line option.

Patch by Marek Šuppa.

- Issue #6074: Ensure cached bytecode files can always be updated by the

user that created them, even when the source file is read-only.

- Issue #14783: Improve int() docstring and switch docstrings for str(),

range(), and slice() to use multi-line signatures.

- Issue #16160: Subclass support now works for types.SimpleNamespace.

- Issue #15379: Fix passing of non-BMP characters as integers for the charmap

decoder (already working as unicode strings). Patch by Serhiy Storchaka.

- Issue #15144: Fix possible integer overflow when handling pointers as integer

values, by using `Py_uintptr_t` instead of `size_t`. Patch by Serhiy

Storchaka.

- Issue #15965: Explicitly cast `AT_FDCWD` as (int). Required on Solaris 10

(which defines `AT_FDCWD` as ``0xffd19553``), harmless on other platforms.

- Issue #15839: Convert SystemErrors in `super()` to RuntimeErrors.

- Issue #15846: Fix SystemError which happened when using `ast.parse()` in an

exception handler on code with syntax errors.

- Issue #15801: Make sure mappings passed to '%' formatting are actually

subscriptable.

- Issue #15111: __import__ should let ImportError propagate when a module that

is imported as a side-effect of using fromlist tries to import a module

that cannot be found.

Library

-------

- Issue #16992: On Windows in signal.set_wakeup_fd, validate the file

descriptor argument.

- Issue #16422: For compatibility with the Python version, the C version of

decimal now uses strings instead of integers for rounding mode constants.

- Issue #15861: tkinter now correctly works with lists and tuples containing

strings with whitespaces, backslashes or unbalanced braces.

- Issue #10527: Use poll() instead of select() for multiprocessing pipes.

- Issue #9720: zipfile now writes correct local headers for files larger than

4 GiB.

- Issue #16955: Fix the poll() method for multiprocessing's socket

connections on Windows.

- SSLContext.load_dh_params() now properly closes the input file.

- Issue #16829: IDLE printing no longer fails if there are spaces or other

special characters in the file path.

- Issue #16900: Issue a ResourceWarning when an ssl socket is left unclosed.

- Issue #13899: \A, \Z, and \B now correctly match the A, Z, and B literals

when used inside character classes (e.g. '[\A]'). Patch by Matthew Barnett.

- Issue #15545: Fix regression in sqlite3's iterdump method where it was

failing if the connection used a row factory (such as sqlite3.Row) that

produced unsortable objects. (Regression was introduced by fix for 9750).

- Issue #16491: IDLE now prints chained exception tracebacks.

- Issue #15972: Fix error messages when os functions expecting a file name or

file descriptor receive the incorrect type.

- Issue #16828: Fix error incorrectly raised by bz2.compress(b'') and

bz2.BZ2Compressor.compress(b''). Initial patch by Martin Packman.

- Issue #16541: tk_setPalette() now works with keyword arguments.

- Issue #16820: In configparser, `parser.popitem()` no longer raises ValueError.

This makes `parser.clean()` work correctly.

- Issue #16820: In configparser, ``parser['section'] = {}`` now preserves

section order within the parser. This makes `parser.update()` preserve section

order as well.

- Issue #16820: In configparser, ``parser['DEFAULT'] = {}`` now correctly

clears previous values stored in the default section. Same goes for

``parser.update({'DEFAULT': {}})``.

- Issue #16819: IDLE method completion now correctly works for bytes literals.

- Issue #9586: Redefine SEM_FAILED on MacOSX to keep compiler happy.

- Issue 10527: make multiprocessing use poll() instead of select() if available.

- Issue #16688: Now regexes contained backreferences correctly work with

non-ASCII strings. Patch by Matthew Barnett.

- Issue #16485: Now file descriptors are closed if file header patching failed

on closing an aifc file.

- Issue #16165: sched.scheduler.run() no longer blocks a scheduler for other

threads.

- Issue #16641: Default values of sched.scheduler.enter() are no longer

modifiable.

- Issue #16504: IDLE now catches SyntaxErrors raised by tokenizer. Patch by

Roger Serwy.

- Issue #16618: Make glob.glob match consistently across strings and bytes

regarding leading dots. Patch by Serhiy Storchaka.

- Issue #16702: test_urllib2_localnet tests now correctly ignores proxies for

localhost tests.

- Issue #16511: Use default IDLE width and height if config param is not valid.

Patch Serhiy Storchaka.

- Issue #16713: Parsing of 'tel' urls using urlparse separates params from

path.

- Issue #16443: Add docstrings to regular expression match objects.

Patch by Anton Kasyanov.

- Issue #15701: Fix HTTPError info method call to return the headers information.

- Issue #16752: Add a missing import to modulefinder. Patch by Berker Peksag.

- Issue #16646: ftplib.FTP.makeport() might lose socket error details.

(patch by Serhiy Storchaka)

- Issue #16626: Fix infinite recursion in glob.glob() on Windows when the

pattern contains a wildcard in the drive or UNC path. Patch by Serhiy

Storchaka.

- Issue #15783: Except for the number methods, the C version of decimal now

supports all None default values present in decimal.py. These values were

largely undocumented.

- Issue #16298: In HTTPResponse.read(), close the socket when there is no

Content-Length and the incoming stream is finished. Patch by Eran

Rundstein.

- Issue #15872: Fix 3.3 regression introduced by the new fd-based shutil.rmtree

that caused it to not ignore certain errors when ignore_errors was set.

Patch by Alessandro Moura and Serhiy Storchaka.

- Issue #16248: Disable code execution from the user's home directory by

tkinter when the -E flag is passed to Python. Patch by Zachary Ware.

- Issue #16628: Fix a memory leak in ctypes.resize().

- Issue #13614: Fix setup.py register failure with invalid rst in description.

Patch by Julien Courteau and Pierre Paul Lefebvre.

- Issue #13512: Create ~/.pypirc securely (CVE-2011-4944). Initial patch by

Philip Jenvey, tested by Mageia and Debian.

- Issue #7719: Make distutils ignore ``.nfs*`` files instead of choking later

on. Initial patch by SilentGhost and Jeff Ramnani.

- Issue #13120: Allow to call pdb.set_trace() from thread.

Patch by Ilya Sandler.

- Issue #16585: Make CJK encoders support error handlers that return bytes per

PEP 383.

- Issue #10182: The re module doesn't truncate indices to 32 bits anymore.

Patch by Serhiy Storchaka.

- Issue #16573: In 2to3, treat enumerate() like a consuming call, so superfluous

list() calls aren't added to filter(), map(), and zip() which are directly

passed enumerate().

- Issue #16476: Fix json.tool to avoid including trailing whitespace.

- Issue #16549: Make json.tool work again on Python 3 and add tests.

Initial patch by Berker Peksag and Serhiy Storchaka.

- Issue #12848: The pure Python pickle implementation now treats object

lengths as unsigned 32-bit integers, like the C implementation does.

Patch by Serhiy Storchaka.

- Issue #16408: Fix file descriptors not being closed in error conditions

in the zipfile module. Patch by Serhiy Storchaka.

- Issue #16481: multiprocessing no longer leaks process handles on Windows.

- Issue #16140: The subprocess module no longer double closes its child

subprocess.PIPE parent file descriptors on child error prior to exec().

- Remove a bare print to stdout from the subprocess module that could have

happened if the child process wrote garbage to its pre-exec error pipe.

- Issue #16327: The subprocess module no longer leaks file descriptors

used for stdin/stdout/stderr pipes to the child when fork() fails.

- Issue #14396: Handle the odd rare case of waitpid returning 0 when not

expected in subprocess.Popen.wait().

- Issue #16411: Fix a bug where zlib.decompressobj().flush() might try to access

previously-freed memory. Patch by Serhiy Storchaka.

- Issue #16357: fix calling accept() on a SSLSocket created through

SSLContext.wrap_socket(). Original patch by Jeff McNeil.

- Issue #16409: The reporthook callback made by the legacy

urllib.request.urlretrieve API now properly supplies a constant non-zero

block_size as it did in Python 3.2 and 2.7. This matches the behavior of

urllib.request.URLopener.retrieve.

- Issue #16431: Use the type information when constructing a Decimal subtype

from a Decimal argument.

- Issue #16350: zlib.decompressobj().decompress() now accumulates data from

successive calls after EOF in unused_data, instead of only saving the argument

to the last call. decompressobj().flush() now correctly sets unused_data and

unconsumed_tail. A bug in the handling of MemoryError when setting the

unconsumed_tail attribute has also been fixed. Patch by Serhiy Storchaka.

- Issue #12759: sre_parse now raises a proper error when the name of the group

is missing. Initial patch by Serhiy Storchaka.

- Issue #16152: fix tokenize to ignore whitespace at the end of the code when

no newline is found. Patch by Ned Batchelder.

- Issue #1207589: Add Cut/Copy/Paste items to IDLE right click Context Menu

Patch by Todd Rovito.

- Issue #16230: Fix a crash in select.select() when one the lists changes

size while iterated on. Patch by Serhiy Storchaka.

- Issue #16228: Fix a crash in the json module where a list changes size

while it is being encoded. Patch by Serhiy Storchaka.

- Issue #14897: Enhance error messages of struct.pack and

struct.pack_into. Patch by Matti Mäki.

- Issue #12890: cgitb no longer prints spurious <p> tags in text

mode when the logdir option is specified.

- Issue #16307: Fix multiprocessing.Pool.map_async not calling its callbacks.

Patch by Janne Karila.

- Issue #16250: Fix URLError invocation with proper args.

- Issue #16116: Fix include and library paths to be correct when building C

extensions in venvs.

- Issue #16245: Fix the value of a few entities in html.entities.html5.

- Issue #14398: Fix size truncation and overflow bugs in the bz2 module.

- Issue #16220: wsgiref now always calls close() on an iterable response.

Patch by Brent Tubbs.

- Issue #16270: urllib may hang when used for retrieving files via FTP by using

a context manager. Patch by Giampaolo Rodola'.

- Issue #16461: Wave library should be able to deal with 4GB wav files,

and sample rate of 44100 Hz.

- Issue #16176: Properly identify Windows 8 via platform.platform()

- Issue #16114: The subprocess module no longer provides a misleading error

message stating that args[0] did not exist when either the cwd or executable

keyword arguments specified a path that did not exist.

- Issue #16169: Fix ctypes.WinError()'s confusion between errno and winerror.

- Issue #16076: Made _elementtree.Element pickleable in a way that is compatible

with the Python Element. Pickling/unpickling of xml.etree.ElementTree.Element

works again - this was a temporary regression from 3.2 where the by-default

imported _elementtree had no pickling capability.

- Issue #16089: Allow ElementTree.TreeBuilder to work again with a non-Element

element_factory (fixes a regression in SimpleTAL).

- Issue #16913: Fix Element.itertext()'s handling of text with XML entities.,

- Issue #16034: Fix performance regressions in the new `bz2.BZ2File`

implementation. Initial patch by Serhiy Storchaka.

- Issue #16112: platform.architecture does not correctly escape argument to

/usr/bin/file. Patch by David Benjamin.

- Issue #15756: `subprocess.poll()` now properly handles `errno.ECHILD` to

return a returncode of 0 when the child has already exited or cannot be waited

on.

- Issue #15323: Improve failure message of `Mock.assert_called_once_with()`.

- Issue #16064: ``unittest -m`` claims executable is "python", not "python3".

- Issue #12376: Pass on parameters in `TextTestResult.__init__()` super call.

- Issue #15222: Insert blank line after each message in mbox mailboxes.

- Issue #16013: Fix `csv.Reader` parsing issue with ending quote characters.

Patch by Serhiy Storchaka.

- Issue #15421: Fix an OverflowError in `Calendar.itermonthdates()` after

`datetime.MAXYEAR`. Patch by Cédric Krier.

- Issue #15970: `xml.etree.ElementTree` now serializes correctly the empty HTML

elements 'meta' and 'param'.

- Issue #15842: The `SocketIO.{readable,writable,seekable}` methods now raise

ValueError when the file-like object is closed. Patch by Alessandro Moura.

- Issue #15876: Fix a refleak in the `curses` module: window.encoding.

- Issue #15881: Fix `atexit` hook in `multiprocessing`. Original patch by Chris

McDonough.

- Issue #15841: The readable(), writable() and seekable() methods of

`io.BytesIO` and `io.StringIO` objects now raise ValueError when the object

has been closed. Patch by Alessandro Moura.

- Issue #16126: PyErr_Format format mismatch in _testcapimodule.c.

Patch by Serhiy Storchaka.

- Issue #15447: Use `subprocess.DEVNULL` in webbrowser, instead of opening

`os.devnull` explicitly and leaving it open.

- Issue #15509: `webbrowser.UnixBrowser` no longer passes empty arguments to

Popen when ``%action`` substitutions produce empty strings.

- Issue #12776, issue #11839: Call `argparse` type function (specified by

add_argument) only once. Before, the type function was called twice in the

case where the default was specified and the argument was given as well. This

was especially problematic for the FileType type, as a default file would

always be opened, even if a file argument was specified on the command line.

- Issue #15906: Fix a regression in `argparse` caused by the preceding change,

when ``action='append'``, ``type='str'`` and ``default=[]``.

Tests

-----

- Issue #16923: Fix ResourceWarnings in test_ssl.

- Issue #15539: Added regression tests for Tools/scripts/pindent.py.

- Issue #16925: test_configparser now works with unittest test discovery.

Patch by Zachary Ware.

- Issue #16918: test_codecs now works with unittest test discovery.

Patch by Zachary Ware.

- Issue #16919: test_crypt now works with unittest test discovery.

Patch by Zachary Ware.

- Issue #16910: test_bytes, test_unicode, and test_userstring now work with

unittest test discovery. Patch by Zachary Ware.

- Issue #16905: test_warnings now works with unittest test discovery.

Initial patch by Berker Peksag.

- Issue #16898: test_bufio now works with unittest test discovery.

Patch by Zachary Ware.

- Issue #16888: test_array now works with unittest test discovery.

Patch by Zachary Ware.

- Issue #16896: test_asyncore now works with unittest test discovery.

Patch by Zachary Ware.

- Issue #16897: test_bisect now works with unittest test discovery.

Initial patch by Zachary Ware.

- Issue #16852: test_genericpath, test_posixpath, test_ntpath, and test_macpath

now work with unittest test discovery. Patch by Zachary Ware.

- Issue #16748: test_heapq now works with unittest test discovery.

- Issue #15324: Fix regrtest parsing of --fromfile, --match, and --randomize

options.

- Issue #16664: Add regression tests for glob's behaviour concerning entries

starting with a ".". Patch by Sebastian Kreft.

- Issue #16559: Add more tests for the json module, including some from the

official test suite at json.org. Patch by Serhiy Storchaka.

- Issue #16661: Fix the `os.getgrouplist()` test by not assuming that it gives

the same output as :command:`id -G`.

- Issue #16115: Add some tests for the executable argument to

subprocess.Popen(). Initial patch by Kushal Das.

- Issue #15304: Fix warning message when `os.chdir()` fails inside

`test.support.temp_cwd()`. Patch by Chris Jerdonek.

- Issue #15802: Fix test logic in `TestMaildir.test_create_tmp()`. Patch by

Serhiy Storchaka.

- Issue #15557: Add a test suite for the `webbrowser` module, thanks to Anton

Barkovsky.

Build

-----

- Issue #16836: Enable IPv6 support even if IPv6 is disabled on the build host.

- Cross compiling needs host and build settings. configure no longer

creates a broken PYTHON_FOR_BUILD variable when --build is missing.

- Fix cross compiling issue in setup.py, ensure that lib_dirs and inc_dirs are

defined in cross compiling mode, too.

- Issue #16593: Have BSD 'make -s' do the right thing, thanks to Daniel Shahaf

- Issue #16262: fix out-of-src-tree builds, if mercurial is not installed.

- Issue #15298: ensure _sysconfigdata is generated in build directory, not

source directory.

- Issue #15833: Fix a regression in 3.3 that resulted in exceptions being

raised if importlib failed to write byte-compiled files. This affected

attempts to build Python out-of-tree from a read-only source directory.

- Issue #15923: Fix a mistake in ``asdl_c.py`` that resulted in a TypeError

after 2801bf875a24 (see #15801).

- Issue #15819: Make sure we can build Python out-of-tree from a read-only

source directory. (Somewhat related to issue #9860.)

Tools/Demos

-----------

- Issue #13301: use ast.literal_eval() instead of eval() in Tools/i18n/msgfmt.py

Patch by Serhiy Storchaka.

Documentation

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

- Issue #13094: add "Why do lambdas defined in a loop with different values

all return the same result?" programming FAQ.

- Issue #14901: Update portions of the Windows FAQ.

Patch by Ashish Nitin Patil.

- Issue #16267: Better document the 3.3+ approach to combining

@abstractmethod with @staticmethod, @classmethod and @property

- Issue #15209: Clarify exception chaining description in exceptions module

documentation

- Issue #15990: Improve argument/parameter documentation.

- Issue #16209: Move the documentation for the str built-in function to a new

str class entry in the "Text Sequence Type" section.

- Issue #13538: Improve str() and object.__str__() documentation.

- Issue #16489: Make it clearer that importlib.find_loader() requires any and

all packages to be separately imported.

- Issue #16400: Update the description of which versions of a given package

PyPI displays.

- Issue #15677: Document that zlib and gzip accept a compression level of 0 to

mean 'no compression'. Patch by Brian Brazil.

- Issue #8040: added a version switcher to the documentation. Patch by

Yury Selivanov.

- Additional comments and some style changes in the concurrent.futures URL

retrieval example

- Issue #16115: Improve subprocess.Popen() documentation around args, shell,

and executable arguments.

- Issue #15533: Clarify docs and add tests for `subprocess.Popen()`'s cwd

argument.

- Issue #15979: Improve timeit documentation.

- Issue #16036: Improve documentation of built-in `int()`'s signature and

arguments.

- Issue #15935: Clarification of `argparse` docs, re: add_argument() type and

default arguments. Patch contributed by Chris Jerdonek.

- Issue #11964: Document a change in v3.2 to the behavior of the indent

parameter of json encoding operations.

Tools/Demos

-----------

- Issue #15539: Fix a number of bugs in Tools/scripts/pindent.py. Now

pindent.py works with a "with" statement. pindent.py no longer produces

improper indentation. pindent.py now works with continued lines broken after

"class" or "def" keywords and with continuations at the start of line.

- Issue #15378: Fix Tools/unicode/comparecodecs.py. Patch by Serhiy Storchaka.

What's New in Python 3.3.0?

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

*Release date: 29-Sep-2012*

Core and Builtins

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

- Issue #16046: Fix loading sourceless legacy .pyo files.

- Issue #16060: Fix refcounting bug when `__trunc__()` returns an object whose

`__int__()` gives a non-integer. Patch by Serhiy Storchaka.

Extension Modules

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

- Issue #16012: Fix a regression in pyexpat. The parser's `UseForeignDTD()`

method doesn't require an argument again.

What's New in Python 3.3.0 Release Candidate 3?

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

*Release date: 23-Sep-2012*

Core and Builtins

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

- Issue #15900: Fix reference leak in `PyUnicode_TranslateCharmap()`.

- Issue #15926: Fix crash after multiple reinitializations of the interpreter.

- Issue #15895: Fix FILE pointer leak in one error branch of

`PyRun_SimpleFileExFlags()` when filename points to a pyc/pyo file, closeit is

false an and set_main_loader() fails.

- Fixes for a few crash and memory leak regressions found by Coverity.

Library

-------

- Issue #15882: Change `_decimal` to accept any coefficient tuple when

constructing infinities. This is done for backwards compatibility with

decimal.py: Infinity coefficients are undefined in _decimal (in accordance

with the specification).

- Issue #15925: Fix a regression in `email.util` where the `parsedate()` and

`parsedate_tz()` functions did not return None anymore when the argument could

not be parsed.

Extension Modules

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

- Issue #15973: Fix a segmentation fault when comparing datetime timezone

objects.

- Issue #15977: Fix memory leak in Modules/_ssl.c when the function

_set_npn_protocols() is called multiple times, thanks to Daniel Sommermann.

- Issue #15969: `faulthandler` module: rename dump_tracebacks_later() to

dump_traceback_later() and cancel_dump_tracebacks_later() to

cancel_dump_traceback_later().

- _decimal module: use only C 89 style comments.

What's New in Python 3.3.0 Release Candidate 2?

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

*Release date: 09-Sep-2012*

Core and Builtins

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

- Issue #13992: The trashcan mechanism is now thread-safe. This eliminates

sporadic crashes in multi-thread programs when several long deallocator chains

ran concurrently and involved subclasses of built-in container types.

- Issue #15784: Modify `OSError`.__str__() to better distinguish between errno

error numbers and Windows error numbers.

- Issue #15781: Fix two small race conditions in import's module locking.

Library

-------

- Issue #15847: Fix a regression in argparse, which did not accept tuples as

argument lists anymore.

- Issue #15828: Restore support for C extensions in `imp.load_module()`.

- Issue #15340: Fix importing the random module when ``/dev/urandom`` cannot be

opened. This was a regression caused by the hash randomization patch.

- Issue #10650: Deprecate the watchexp parameter of the `Decimal.quantize()`

method.

- Issue #15785: Modify `window.get_wch()` API of the curses module: return a

character for most keys, and an integer for special keys, instead of always

returning an integer. So it is now possible to distinguish special keys like

keypad keys.

- Issue #14223: Fix `window.addch()` of the curses module for special characters

like curses.ACS_HLINE: the Python function addch(int) and addch(bytes) is now

calling the C function waddch()/mvwaddch() (as it was done in Python 3.2),

instead of wadd_wch()/mvwadd_wch(). The Python function addch(str) is still

calling the C function wadd_wch()/mvwadd_wch() if the Python curses is linked

to libncursesw.

Build

-----

- Issue #15822: Really ensure 2to3 grammar pickles are properly installed

(replaces fixes for Issue #15645).

Documentation

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

- Issue #15814: The memoryview enhancements in 3.3.0 accidentally permitted the

hashing of multi-dimensional memorviews and memoryviews with multi-byte item

formats. The intended restrictions have now been documented - they will be

correctly enforced in 3.3.1.

What's New in Python 3.3.0 Release Candidate 1?

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

*Release date: 25-Aug-2012*

Core and Builtins

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

- Issue #15573: memoryview comparisons are now performed by value with full

support for any valid struct module format definition.

- Issue #15316: When an item in the fromlist for `__import__()` doesn't exist,

don't raise an error, but if an exception is raised as part of an import do

let that propagate.

- Issue #15778: Ensure that ``str(ImportError(msg))`` returns a str even when

msg isn't a str.

- Issue #2051: Source file permission bits are once again correctly copied to

the cached bytecode file. (The migration to importlib reintroduced this

problem because these was no regression test. A test has been added as part of

this patch)

- Issue #15761: Fix crash when ``PYTHONEXECUTABLE`` is set on Mac OS X.

- Issue #15726: Fix incorrect bounds checking in PyState_FindModule. Patch by

Robin Schreiber.

- Issue #15604: Update uses of `PyObject_IsTrue()` to check for and handle

errors correctly. Patch by Serhiy Storchaka.

- Issue #14846: `importlib.FileFinder` now handles the case where the directory

being searched is removed after a previous import attempt.

Library

-------

- Issue #13370: Ensure that ctypes works on Mac OS X when Python is compiled

using the clang compiler.

- Issue #13072: The array module's 'u' format code is now deprecated and will be

removed in Python 4.0.

- Issue #15544: Fix Decimal.__float__ to work with payload-carrying NaNs.

- Issue #15776: Allow pyvenv to work in existing directory with --clean.

- Issue #15249: email's BytesGenerator now correctly mangles From lines (when

requested) even if the body contains undecodable bytes.

- Issue #15777: Fix a refleak in _posixsubprocess.

- Issue ##665194: Update `email.utils.localtime` to use datetime.astimezone and

correctly handle historic changes in UTC offsets.

- Issue #15199: Fix JavaScript's default MIME type to application/javascript.

Patch by Bohuslav Kabrda.

- Issue #12643: `code.InteractiveConsole` now respects `sys.excepthook` when

displaying exceptions. Patch by Aaron Iles.

- Issue #13579: `string.Formatter` now understands the 'a' conversion specifier.

- Issue #15595: Fix ``subprocess.Popen(universal_newlines=True)`` for certain

locales (utf-16 and utf-32 family). Patch by Chris Jerdonek.

- Issue #15477: In cmath and math modules, add workaround for platforms whose

system-supplied log1p function doesn't respect signs of zeros.

- Issue #15715: `importlib.__import__()` will silence an ImportError when the

use of fromlist leads to a failed import.

- Issue #14669: Fix pickling of connections and sockets on Mac OS X by

sending/receiving an acknowledgment after file descriptor transfer.

TestPicklingConnection has been reenabled for Mac OS X.

- Issue #11062: Fix adding a message from file to Babyl mailbox.

- Issue #15646: Prevent equivalent of a fork bomb when using `multiprocessing`

on Windows without the ``if __name__ == '__main__'`` idiom.

- Issue #15678: Fix IDLE menus when started from OS X command line (3.3.0b2

regression).

C API

-----

Extension Modules

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

Tools/Demos

-----------

Documentation

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

- Issue #14674: Add a discussion of the `json` module's standard compliance.

Patch by Chris Rebert.

- Create a 'Concurrent Execution' section in the docs, and split up the

'Optional Operating System Services' section to use a more user-centric

classification scheme (splitting them across the new CE section, IPC and text

processing). Operating system limitatons can be reflected with the Sphinx

``:platform:`` tag, it doesn't make sense as part of the Table of Contents.

- Issue #4966: Bring the sequence docs up to date for the Py3k transition and

the many language enhancements since they were original written.

- The "path importer" misnomer has been replaced with Eric Snow's

more-awkward-but-at-least-not-wrong suggestion of "path based finder" in the

import system reference docs.

- Issue #15640: Document `importlib.abc.Finder` as deprecated.

- Issue #15630: Add an example for "continue" stmt in the tutorial. Patch by

Daniel Ellis.

Tests

-----

- Issue #15747: ZFS always returns EOPNOTSUPP when attempting to set the

UF_IMMUTABLE flag (via either chflags or lchflags); refactor affected tests in

test_posix.py to account for this.

- Issue #15285: Refactor the approach for testing connect timeouts using two

external hosts that have been configured specifically for this type of test.

- Issue #15743: Remove the deprecated method usage in `urllib` tests. Patch by

Jeff Knupp.

- Issue #15615: Add some tests for the `json` module's handling of invalid input

data. Patch by Kushal Das.

Build

-----

- Output lib files for PGO build into PGO directory.

- Pick up 32-bit launcher from PGO directory on 64-bit PGO build.

- Drop ``PC\python_nt.h`` as it's not used. Add input dependency on custom

build step.

- Issue #15511: Drop explicit dependency on pythonxy.lib from _decimal amd64

configuration.

- Add missing PGI/PGO configurations for pywlauncher.

- Issue #15645: Ensure 2to3 grammar pickles are properly installed.

What's New in Python 3.3.0 Beta 2?

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

*Release date: 12-Aug-2012*

Core and Builtins

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

- Issue #15568: Fix the return value of ``yield from`` when StopIteration is

raised by a custom iterator.

- Issue #13119: `sys.stdout` and `sys.stderr` are now using "\r\n" newline on

Windows, as Python 2.

- Issue #15534: Fix the fast-search function for non-ASCII Unicode strings.

- Issue #15508: Fix the docstring for `__import__()` to have the proper default

value of 0 for 'level' and to not mention negative levels since they are not

supported.

- Issue #15425: Eliminated traceback noise from more situations involving

importlib.

- Issue #14578: Support modules registered in the Windows registry again.

- Issue #15466: Stop using TYPE_INT64 in marshal, to make importlib.h (and other

byte code files) equal between 32-bit and 64-bit systems.

- Issue #1692335: Move initial exception args assignment to

`BaseException.__new__()` to help pickling of naive subclasses.

- Issue #12834: Fix `PyBuffer_ToContiguous()` for non-contiguous arrays.

- Issue #15456: Fix code `__sizeof__()` after #12399 change. Patch by Serhiy

Storchaka.

- Issue #15404: Refleak in PyMethodObject repr.

- Issue #15394: An issue in `PyModule_Create()` that caused references to be

leaked on some error paths has been fixed. Patch by Julia Lawall.

- Issue #15368: An issue that caused bytecode generation to be non-deterministic

has been fixed.

- Issue #15202: Consistently use the name "follow_symlinks" for new parameters

in os and shutil functions.

- Issue #15314: ``__main__.__loader__`` is now set correctly during interpreter

startup.

- Issue #15111: When a module imported using 'from import' has an ImportError

inside itself, don't mask that fact behind a generic ImportError for the

module itself.

- Issue #15293: Add GC support to the AST base node type.

- Issue #15291: Fix a memory leak where AST nodes where not properly

deallocated.

- Issue #15110: Fix the tracebacks generated by "import xxx" to not show the

importlib stack frames.

- Issue #16369: Global PyTypeObjects not initialized with PyType_Ready(...).

- Issue #15020: The program name used to search for Python's path is now

"python3" under Unix, not "python".

- Issue #15897: zipimport.c doesn't check return value of fseek().

Patch by Felipe Cruz.

- Issue #15033: Fix the exit status bug when modules invoked using -m switch,

return the proper failure return value (1). Patch contributed by Jeff Knupp.

- Issue #15229: An `OSError` subclass whose __init__ doesn't call back

OSError.__init__ could produce incomplete instances, leading to crashes when

calling str() on them.

- Issue #15307: Virtual environments now use symlinks with framework builds on

Mac OS X, like other POSIX builds.

Library

-------

- Issue #14590: configparser now correctly strips inline comments when delimiter

occurs earlier without preceding space.

- Issue #15424: Add a `__sizeof__()` implementation for array objects. Patch by

Ludwig Hähne.

- Issue #15576: Allow extension modules to act as a package's __init__ module.

- Issue #15502: Have `importlib.invalidate_caches()` work on `sys.meta_path`

instead of `sys.path_importer_cache`.

- Issue #15163: Pydoc shouldn't list __loader__ as module data.

- Issue #15471: Do not use mutable objects as defaults for

`importlib.__import__()`.

- Issue #15559: To avoid a problematic failure mode when passed to the bytes

constructor, objects in the ipaddress module no longer implement `__index__()`

(they still implement `__int__()` as appropriate).

- Issue #15546: Fix handling of pathological input data in the peek() and

read1() methods of the BZ2File, GzipFile and LZMAFile classes.

- Issue #13052: Fix IDLE crashing when replace string in Search/Replace dialog

ended with ``\``. Patch by Roger Serwy.

- Issue #12655: Instead of requiring a custom type, `os.sched_getaffinity()` and