+++++++++++

Python News

+++++++++++

(editors: check NEWS.help for information about editing NEWS using ReST.)

What's New in Python 3.1.2?

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

*Release date: 2010-03-20*

Core and Builtins

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

- Issue #7173: Generator finalization could invalidate sys.exc_info().

Library

-------

- Issue #2698: The --compiler ignored was ignored for distutils' build_ext.

- Issue #4961: Inconsistent/wrong result of askyesno function in tkMessageBox

with Tcl/Tk-8.5.

- Issue #7356: ctypes.util: Make parsing of ldconfig output independent of

the locale.

What's New in Python 3.1.2 release candidate 1?

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

*Release date: 2010-03-06*

Core and Builtins

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

- Issue #7544: Preallocate thread memory before creating the thread to avoid

a fatal error in low memory condition.

- Issue #7820: The parser tokenizer restores all bytes in the right if

the BOM check fails.

- Handle errors from looking up __prepare__ correctly.

- Issue #5939: Add additional runtime checking to ensure a valid capsule

in Modules/_ctypes/callproc.c.

- Issue #7309: Fix unchecked attribute access when converting

UnicodeEncodeError, UnicodeDecodeError, and UnicodeTranslateError to

strings.

- Issue #6902: Fix problem with built-in types format incorrectly with

0 padding.

- Issue #7988: Fix default alignment to be right aligned for

complex.__format__. Now it matches other numeric types.

- Issue #7385: Fix a crash in `MemoryView_FromObject` when

`PyObject_GetBuffer` fails. Patch by Florent Xicluna.

- Issue #7788: Fix an interpreter crash produced by deleting a list

slice with very large step value.

- Issue #7561: Operations on empty bytearrays (such as `int(bytearray())`)

could crash in many places because of the PyByteArray_AS_STRING() macro

returning NULL. The macro now returns a statically allocated empty

string instead.

- Issue #7632: Fix various str -> float conversion bugs present in 2.7

alpha 2, including: (1) a serious 'wrong output' bug that could

occur for long (> 40 digit) input strings, (2) a crash in dtoa.c

that occurred in debug builds when parsing certain long numeric

strings corresponding to subnormal values, (3) a memory leak for

some values large enough to cause overflow, and (4) a number of

flaws that could lead to incorrectly rounded results.

- Issue #7604: Deleting an unset slotted attribute did not raise an

AttributeError.

- Issue #7466: segmentation fault when the garbage collector is called

in the middle of populating a tuple. Patch by Florent Xicluna.

- Issue #7419: setlocale() could crash the interpreter on Windows when called

with invalid values.

- Issue #6077: On Windows, files opened with tempfile.TemporaryFile in "wt+"

mode would appear truncated on the first '0x1a' byte (aka. Ctrl+Z).

- Issue #7085: Fix crash when importing some extensions in a thread

on MacOSX 10.6.

- Issue #7298: fixes for range and reversed(range(...)). Iteration

over range(a, b, c) incorrectly gave an empty iterator when a, b and

c fit in C long but the length of the range did not. Also fix

several cases where reversed(range(a, b, c)) gave wrong results, and

fix a refleak for reversed(range(a, b, c)) with large arguments.

- Issue #7244: itertools.izip_longest() no longer ignores exceptions

raised during the formation of an output tuple.

- Issue #3297: On wide unicode builds, do not split unicode characters into

surrogates.

- Issue #1722344: threading._shutdown() is now called in Py_Finalize(), which

fixes the problem of some exceptions being thrown at shutdown when the

interpreter is killed. Patch by Adam Olsen.

- Issue #7065: Fix a crash in bytes.maketrans and bytearray.maketrans when

using byte values greater than 127. Patch by Derk Drukker.

- Issue #7019: Raise ValueError when unmarshalling bad long data, instead

of producing internally inconsistent Python longs.

- Issue #6990: Fix threading.local subclasses leaving old state around

after a reference cycle GC which could be recycled by new locals.

- Issue #6846: Fix bug where bytearray.pop() returns negative integers.

- Issue #6750: A text file opened with io.open() could duplicate its output

when writing from multiple threads at the same time.

Library

-------

- Issue #6509: fix re.sub to work properly when the pattern, the string, and

the replacement were all bytes. Patch by Antoine Pitrou.

- Issue #1054943: Fix unicodedata.normalize('NFC', text) for the Public Review

Issue #29

- Issue #7494: fix a crash in _lsprof (cProfile) after clearing the profiler,

reset also the pointer to the current pointer context.

- Issue #7250: Fix info leak of os.environ across multi-run uses of

wsgiref.handlers.CGIHandler.

- Issue #1729305: Fix doctest to handle encode error with "backslashreplace".

- Issue #691291: codecs.open() should not convert end of lines on reading and

writing.

- Issue #7959: ctypes callback functions are now registered correctly

with the cycle garbage collector.

- Issue #6666: fix bug in trace.py that applied the list of directories

to be ignored only to the first file. Noted by Bogdan Opanchuk.

- Issue #7597: curses.use_env() can now be called before initscr().

Noted by Kan-Ru Chen.

- Issue #7310: fix the __repr__ of os.environ to show the environment variables.

- Issue #7970: email.Generator.flatten now correctly flattens message/rfc822

messages parsed by email.Parser.HeaderParser.

- Issue #7361: Importlib was not handling bytecode files less than 8 bytes in

length properly.

- Issue #7835: shelve should no longer produce mysterious warnings during

interpreter shutdown.

- Issue #6233: ElementTree failed converting unicode characters to XML

entities when they could't be represented in the requested output

encoding. Patch by Jerry Chen.

- Issue #4772: Raise a ValueError when an unknown Bluetooth protocol is

specified, rather than fall through to AF_PACKET (in the `socket` module).

Also, raise ValueError rather than TypeError when an unknown TIPC address

type is specified. Patch by Brian Curtin.

- Issue #6939: Fix file I/O objects in the `io` module to keep the original

file position when calling `truncate()`. It would previously change the

file position to the given argument, which goes against the tradition of

ftruncate() and other truncation APIs. Patch by Pascal Chambon.

- Issue #7792: Registering non-classes to ABCs raised an obscure error.

- Issue #7785: Don't accept bytes in FileIO.write().

- Issue #7773: Fix an UnboundLocalError in platform.linux_distribution() when

the release file is empty.

- Issue #7561: Fix crashes when using bytearray objects with the posix

module.

- Issue #1670765: Prevent email.generator.Generator from re-wrapping

headers in multipart/signed MIME parts, which fixes one of the sources of

invalid modifications to such parts by Generator.

- Issue #7701: Fix crash in binascii.b2a_uu() in debug mode when given a

1-byte argument. Patch by Victor Stinner.

- Issue #3299: Fix possible crash in the _sre module when given bad

argument values in debug mode. Patch by Victor Stinner.

- Issue #7681: Use floor division in appropiate places in the wave module.

- Issue #5372: Drop the reuse of .o files in Distutils' ccompiler (since

Extension extra options may change the output without changing the .c

file). Initial patch by Collin Winter.

- Issue #7617: Make sure distutils.unixccompiler.UnixCCompiler recognizes

gcc when it has a fully qualified configuration prefix. Initial patch

by Arfrever.

- Issue #7105: Make WeakKeyDictionary and WeakValueDictionary robust against

the destruction of weakref'ed objects while iterating.

- Issue #7455: Fix possible crash in cPickle on invalid input. Patch by

Victor Stinner.

- Issue #6511: ZipFile now raises BadZipfile (instead of an IOError) when

opening an empty or very small file.

- Issue #7556: Make sure Distutils' msvc9compile reads and writes the

MSVC XML Manifest file in text mode so string patterns can be used

in regular expressions.

- Issue #7552: Removed line feed in the base64 Authorization header in

the Distutils upload command to avoid an error when PyPI reads it.

This occurs on long passwords. Initial patch by JP St. Pierre.

- Issue #7231: urllib2 cannot handle https with proxy requiring auth. Patch by

Tatsuhiro Tsujikawa.

- Issue #4757: `zlib.compress` and other methods in the zlib module now

raise a TypeError when given an `str` object (rather than a `bytes`-like

object). Patch by Victor Stinner and Florent Xicluna.

- Issue #7349: Make methods of file objects in the io module accept None as an

argument where file-like objects (ie StringIO and BytesIO) accept them to mean

the same as passing no argument.

- Issue #5949: added check for correct lineends in input from IMAP server

in imaplib.

- Fix variations of extending deques: d.extend(d) d.extendleft(d) d+=d

- Issue #6986: Fix crash in the JSON C accelerator when called with the

wrong parameter types. Patch by Victor Stinner.

- Issue #1923: Fixed the removal of meaningful spaces when PKG-INFO is

generated in Distutils. Patch by Stephen Emslie.

- Issue #4120: Drop reference to CRT from manifest when building extensions with

msvc9compiler.

- Issue #7410: deepcopy of itertools.count was resetting the count.

- Issue #4486: When an exception has an explicit cause, do not print its

implicit context too. This affects the `traceback` module as well as

built-in exception printing.

- Issue #1488943: difflib.Differ() doesn't always add hints for tab characters

- Issue #7354: distutils.tests.test_msvc9compiler - dragfullwindows can

be 2.

- Issue #3976: pprint for sets, frozensets, and dicts now succeed when

they contain unorderable types.

- Issue #5037: Proxy the __bytes__ special method instead to __bytes__ instead

of __str__.

- Issue #7341: Close the internal file object in the TarFile constructor in

case of an error.

- Issue #7293: distutils.test_msvc9compiler is fixed to work on any fresh

Windows box. Help provided by David Bolen.

- Issue #7328: pydoc no longer corrupts sys.path when run with the '-m' switch

- Issue #7318: multiprocessing now uses a timeout when it fails to establish

a connection with another process, rather than looping endlessly. The

default timeout is 20 seconds, which should be amply sufficient for

local connections.

- Issue #7282: Fix a memory leak when an RLock was used in a thread other

than those started through `threading.Thread` (for example, using

`_thread.start_new_thread()`).

- Issue #7187: Importlib would not silence the IOError raised when trying to

write new bytecode when it was made read-only.

- Issue #7264: Fix a possible deadlock when deallocating thread-local objects

which are part of a reference cycle.

- Issue #6896: mailbox.Maildir now invalidates its internal cache each time

a modification is done through it. This fixes inconsistencies and test

failures on systems with slightly bogus mtime behaviour.

- Issue #6665: Fix fnmatch to properly match filenames with newlines in them.

- Issue #7246 & Issue #7208: getpass now properly flushes input before

reading from stdin so that existing input does not confuse it and

lead to incorrect entry or an IOError. It also properly flushes it

afterwards to avoid the terminal echoing the input afterwards on

OSes such as Solaris.

- Issue #7233: Fix a number of two-argument Decimal methods to make

sure that they accept an int or long as the second argument. Also

fix buggy handling of large arguments (those with coefficient longer

than the current precision) in shift and rotate.

- Issue #7205: Fix a possible deadlock when using a BZ2File object from

several threads at once.

- Issue #7071: byte-compilation in Distutils is now done with respect to

sys.dont_write_bytecode.

- Issue #7099: Decimal.is_normal now returns True for numbers with exponent

larger than emax.

- Issue #7080: locale.strxfrm() raises a MemoryError on 64-bit non-Windows

platforms, and assorted locale fixes by Derk Drukker.

- Issue #5833: Fix extra space character in readline completion with the

GNU readline library version 6.0.

- Issue #6894: Fixed the issue urllib2 doesn't respect "no_proxy" environment

- Issue #7082: When falling back to the MIME 'name' parameter, the

correct place to look for it is the Content-Type header.

- Make tokenize.detect_coding() normalize utf-8 and iso-8859-1 variants like the

builtin tokenizer.

- Issue #7048: Force Decimal.logb to round its result when that result

is too large to fit in the current precision.

- Issue #6236, #6348: Fix various failures in the I/O library under AIX

and other platforms, when using a non-gcc compiler. Patch by Derk Drukker.

- Issue #6954: Fixed crash when using DISTUTILS_DEBUG flag in Distutils.

- Issue #4606: Passing 'None' if ctypes argtype is set to POINTER(...)

does now always result in NULL.

- Issue #5042: Structure sub-subclass does now initialize correctly

with base class positional arguments.

- Issue #6882: Import uuid creates zombies processes.

- Issue #6635: Fix profiler printing usage message.

- Issue #6888: pdb's alias command was broken when no arguments were given.

- Issue #6795: int(Decimal('nan')) now raises ValueError instead of

returning NaN or raising InvalidContext. Also, fix infinite recursion

in long(Decimal('nan')).

- Issue #6850: Fix bug in Decimal._parse_format_specifier for formats

with no type specifier.

- Issue #6239: ctypes.c_char_p return value must return bytes.

- Issue #6838: Use a list to accumulate the value instead of

repeatedly concatenating strings in http.client's

HTTPResponse._read_chunked providing a significant speed increase

when downloading large files servend with a Transfer-Encoding of 'chunked'.

- Have importlib raise ImportError if None is found in sys.modules for a

module.

- Issue #6794: Fix Decimal.compare_total and Decimal.compare_total_mag: NaN

payloads are now ordered by integer value rather than lexicographically.

- Issue #6163: Fixed HP-UX runtime library dir options in

distutils.unixcompiler. Initial patch by Sridhar Ratnakumar and

Michael Haubenwallner.

- Issue #7066: archive_util.make_archive now restores the cwd if an error is

raised. Initial patch by Ezio Melotti.

- Issue #7481: When a threading.Thread failed to start it would leave the

instance stuck in initial state and present in threading.enumerate().

- Issue #1068268: The subprocess module now handles EINTR in internal

os.waitpid and os.read system calls where appropriate.

Extension Modules

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

- Issue #7670: sqlite3: Fixed crashes when operating on closed connections.

- Stop providing crtassem.h symbols when compiling with Visual Studio 2010, as

msvcr100.dll is not a platform assembly anymore.

- Issue #7078: Set struct.__doc__ from _struct.__doc__.

- Issue #6848: Fix curses module build failure on OS X 10.6.

- Expat: Fix DoS via XML document with malformed UTF-8 sequences

(CVE_2009_3560).

- Issue #7999: os.setreuid() and os.setregid() would refuse to accept a -1

parameter on some platforms such as OS X.

Tests

-----

- Issue #7924: Fix an intermittent 'XXX undetected error' failure in

test_capi (only seen so far on platforms where the curses module

wasn't built), due to an uncleared exception.

- issue #7728: test_timeout was changed to use test_support.bind_port

instead of a hard coded port.

- Issue #7376: instead of running a self-test (which was failing) when called

with no arguments, doctest.py now gives a usage message.

- Issue #7498: test_multiprocessing now uses test.support.find_unused_port

instead of a hardcoded port number in test_rapid_restart.

- Issue #7431: use TESTFN in test_linecache instead of trying to create a

file in the Lib/test directory, which might be read-only for the

user running the tests.

- Issue #7324: add a sanity check to regrtest argument parsing to

catch the case of an option with no handler.

- Issue #6551: test_zipimport could import and then destroy some modules of

the encodings package, which would make other tests fail further down

the road because the internally cached encoders and decoders would point

to empty global variables.

- Issue #7295: Do not use a hardcoded file name in test_tarfile.

- Issue #7270: Add some dedicated unit tests for multi-thread synchronization

primitives such as Lock, RLock, Condition, Event and Semaphore.

- Issue #7248 (part 2): Use a unique temporary directory for importlib source

tests instead of tempfile.tempdir. This prevents the tests from sharing state

between concurrent executions on the same system.

- Issue #7248: In importlib.test.source.util a try/finally block did not make

sure that some referenced objects actually were created in the block before

calling methods on the object.

- Issue #7055: test___all__ now greedily detects all modules which have an

__all__ attribute, rather than using a hardcoded and incomplete list.

- Issue #7058: Added save/restore for argv and os.environ to runtest_inner

in regrtest, with warnings if the called test modifies them.

- Issue #7042: Fix test_signal (test_itimer_virtual) failure on OS X 10.6.

C-API

-----

- Make PyUnicode_CompareWithASCIIString return not equal if the Python string

has '\0' at the end.

- Issue #7414: 'C' code wasn't being skipped properly (for keyword arguments)

in PyArg_ParseTupleAndKeywords.

Build

-----

- Issue #3920, #7903: Define _BSD_SOURCE on OpenBSD 4.4 through 4.9.

- Issue #7632: When Py_USING_MEMORY_DEBUGGER is defined, disable the

private memory allocation scheme in dtoa.c and use PyMem_Malloc and

PyMem_Free instead. Also disable caching of powers of 5.

- Switch to OpenSSL 0.9.8l on Windows.

- Issue #6603: Change READ_TIMESTAMP macro in ceval.c so that it

compiles correctly under gcc on x86-64. This fixes a reported

problem with the --with-tsc build on x86-64.

- Issue #6802: Fix build issues on MacOSX 10.6

- Issue #6801 : symmetric_difference_update also accepts |.

Thanks to Carl Chenet.

- Issue #7541: when using ``python-config`` with a framework install the

compiler might use the wrong library.

- Issue #6491: Allow --with-dbmliborder to specify that no dbms will be built.

- Issue #7589: Only build the nis module when the correct header files are

found.

Documentation

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

- Updating `Using Python` documentation to include description of CPython's

-J and -X options.

- Issue #6556: Fixed the Distutils configuration files location explanation

for Windows.

- Update python manual page (options -B, -O0, -s, environment variables

PYTHONDONTWRITEBYTECODE, PYTHONNOUSERSITE).

What's New in Python 3.1.1?

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

*Release date: 2009-08-13*

Core and Builtins

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

- Issue #6707: dir() on an uninitialized module caused a crash.

- Issue #6540: Fixed crash for bytearray.translate() with invalid parameters.

- Issue #6573: set.union() stopped processing inputs if an instance of self

occurred in the argument chain.

- Issue #6070: On posix platforms import no longer copies the execute bit

from the .py file to the .pyc file if it is set.

- Issue #6428: Since Python 3.0, the __bool__ method must return a bool

object, and not an int. Fix the corresponding error message, and the

documentation.

- Issue #6347: Include inttypes.h as well as stdint.h in pyport.h.

This fixes a build failure on HP-UX: int32_t and uint32_t are

defined in inttypes.h instead of stdint.h on that platform.

- Issue #6373: Fixed a SystemError when encoding with the latin-1 codec and

the 'surrogateescape' error handler, a string which contains unpaired

surrogates.

C-API

-----

- Issue #6624: yArg_ParseTuple with "s" format when parsing argument with

NUL: Bogus TypeError detail string.

- Issue #6405: Remove duplicate type declarations in descrobject.h.

- The code flags for old __future__ features are now available again.

Library

-------

- Issue #6106: telnetlib.Telnet.process_rawq doesn't handle default WILL/WONT

DO/DONT correctly.

- Issue #6126: Fixed pdb command-line usage.

- Issue #6629: Fix a data corruption issue in the new I/O library, which could

occur when writing to a BufferedRandom object (e.g. a file opened in "rb+" or

"wb+" mode) after having buffered a certain amount of data for reading. This

bug was not present in the pure Python implementation.

- Issue #6622: Fix "local variable 'secret' referenced before

assignment" bug in POP3.apop.

- Issue #6637: defaultdict.copy() did not work when the default factory

was left unspecified. Also, the eval/repr round-trip would fail when

the default_factory was None.

- Issue #2715: Remove remnants of Carbon.File from binhex module.

- Issue #6595: The Decimal constructor now allows arbitrary Unicode

decimal digits in input, as recommended by the standard. Previously

it was restricted to accepting [0-9].

- Issues #5155, #5313, #5331: multiprocessing.Process._bootstrap was

unconditionally calling "os.close(sys.stdin.fileno())" resulting in file

descriptor errors

- Issue #1424152: Fix for http.client, urllib.request to support SSL while

working through proxy. Original patch by Christopher Li, changes made by

Senthil Kumaran

- importlib.abc.PyLoader did not inherit from importlib.abc.ResourceLoader like

the documentation said it did even though the code in PyLoader relied on the

abstract method required by ResourceLoader.

- Issue #6431: Make Fraction type return NotImplemented when it doesn't

know how to handle a comparison without loss of precision. Also add

correct handling of infinities and nans for comparisons with float.

- Issue #6415: Fixed warnings.warn segfault on bad formatted string.

- Issue #6358: The exit status of a command started with os.popen() was

reported differently than it did with python 2.x.

- Issue #6323: The pdb debugger did not exit when running a script with a

syntax error.

- Issue #3392: The subprocess communicate() method no longer fails in select()

when file descriptors are large; communicate() now uses poll() when possible.

- Issue #6369: Fix an RLE decompression bug in the binhex module.

- Issue #6344: Fixed a crash of mmap.read() when passed a negative argument.

- Issue #4005: Fixed a crash of pydoc when there was a zip file present in

sys.path.

Extension Modules

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

- Fix a segfault in expat.

- Issue #4509: array.array objects are no longer modified after an operation

failing due to the resize restriction in-place when the object has exported

buffers.

Build

-----

- Issue 4601: 'make install' did not set the appropriate permissions on

directories.

- Issue 5390: Add uninstall icon independent of whether file

extensions are installed.

Test

----

- Fix a test in importlib.test.source.test_abc_loader that was incorrectly

testing when a .pyc file lacked an code object bytecode.

What's New in Python 3.1?

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

*Release date: 27-June-2009*

Core and Builtins

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

- Issue #6334: Fix bug in range length calculation for ranges with

large arguments.

- Issue #6329: Fixed iteration for memoryview objects (it was being blocked

because it wasn't recognized as a sequence).

Library

-------

- Issue #6314: logging.basicConfig() performs extra checks on the "level"

argument.

- Issue #6274: Fixed possible file descriptors leak in subprocess.py

- Accessing io.StringIO.buffer now raises an AttributeError instead of

io.UnsupportedOperation.

- Issue #6271: mmap tried to close invalid file handle (-1) when anonymous.

(On Unix)

- Issue #1202: zipfile module would cause a struct.error when attempting to

store files with a CRC32 > 2**31-1.

Extension Modules

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

- Issue #5590: Remove unused global variable in pyexpat extension.

What's New in Python 3.1 Release Candidate 2?

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

*Release date: 13-June-2009*

Core and Builtins

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

- Fixed SystemError triggered by "range([], 1, -1)".

- Issue #5924: On Windows, a large PYTHONPATH environment variable

(more than 255 characters) would be completely ignored.

- Issue #4547: When debugging a very large function, it was not always

possible to update the lineno attribute of the current frame.

- Issue #5330: C functions called with keyword arguments were not reported by

the various profiling modules (profile, cProfile). Patch by Hagen Fürstenau.

Library

-------

- Issue #6438: Fixed distutils.cygwinccompiler.get_versions : the regular

expression string pattern was trying to match against a bytes returned by

Popen. Tested under win32 to build the py-postgresql project.

- Issue #6258: Support AMD64 in bdist_msi.

- Issue #6195: fixed doctest to no longer try to read 'source' data from

binary files.

- Issue #5262: Fixed bug in next rollover time computation in

TimedRotatingFileHandler.

- Issue #6217: The C implementation of io.TextIOWrapper didn't include the

errors property. Additionally, the errors and encoding properties of StringIO

are always None now.

- Issue #6137: The pickle module now translates module names when loading

or dumping pickles with a 2.x-compatible protocol, in order to make data

sharing and migration easier. This behaviour can be disabled using the

new `fix_imports` optional argument.

- Removed the ipaddr module.

- Issue #3613: base64.{encode,decode}string are now called

base64.{encode,decode}bytes which reflects what type they accept and return.

The old names are still there as deprecated aliases.

- Issue #5767: Remove sgmlop support from xmlrpc.client.

- Issue #6150: Fix test_unicode on wide-unicode builds.

- Issue #6149: Fix initialization of WeakValueDictionary objects from non-empty

parameters.

Windows

-------

- Issue #6221: Delete test registry key before running the test.

- Issue #6158: Package Sine-1000Hz-300ms.aif in MSI file.

C-API

-----

- Issue #5735: Python compiled with --with-pydebug should throw an

ImportError when trying to import modules compiled without

--with-pydebug, and vice-versa.

Build

-----

- Issue #6154: Make sure the intl library is added to LIBS if needed. Also

added LIBS to OS X framework builds.

- Issue #5809: Specifying both --enable-framework and --enable-shared is

an error. Configure now explicity tells you about this.

What's New in Python 3.1 release candidate 1?

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

*Release date: 2009-05-30*

Core and Builtins

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

- Issue #6097: Escape UTF-8 surrogates resulting from mbstocs conversion

of the command line.

- Issue #6012: Add cleanup support to O& argument parsing.

- Issue #6089: Fixed str.format with certain invalid field specifiers

that would raise SystemError.

- Issue #5982: staticmethod and classmethod now expose the wrapped

function with __func__.

- Added support for multiple context managers in the same with-statement.

Deprecated contextlib.nested() which is no longer needed.

- Issue #5829: complex("1e500") no longer raises OverflowError. This

makes it consistent with float("1e500") and interpretation of real

and imaginary literals.

- Issue #3527: Removed Py_WIN_WIDE_FILENAMES which is not used any more.

- Issue #5994: the marshal module now has docstrings.

- Issue #5981: Fix three minor inf/nan issues in float.fromhex:

(1) inf and nan strings with trailing whitespace were incorrectly

rejected; (2) parsing of strings representing infinities and nans

was locale aware; and (3) the interpretation of fromhex('-nan')

didn't match that of float('-nan').

Library

-------

- Issue #4859: Implement PEP 383 for pwd, spwd, and grp.

- smtplib 'login' and 'cram-md5' login are also fixed (see Issue #5259).

- Issue #6121: pydoc now ignores leading and trailing spaces in the

argument to the 'help' function.

- Issue #6118: urllib.parse.quote_plus ignored the encoding and errors

arguments for strings with a space in them.

- collections.namedtuple() was not working with the following field

names: cls, self, tuple, itemgetter, and property.

- In unittest, using a skipping decorator on a class is now equivalent to

skipping every test on the class. The ClassTestSuite class has been removed.

- Issue #6050: Don't fail extracting a directory from a zipfile if

the directory already exists.

- Issue #1309352: fcntl now converts its third arguments to a C `long` rather

than an int, which makes some operations possible under 64-bit Linux (e.g.

DN_MULTISHOT with F_NOTIFY).

- Issue #5761: Add the name of the underlying file to the repr() of various

IO objects.

- Issue #5259: smtplib plain auth login no longer gives a traceback. Fix

by Musashi Tamura, tests by Marcin Bachry.

- Issue #1983: Fix functions taking or returning a process identifier to use

the dedicated C type ``pid_t`` instead of a C ``int``. Some platforms have

a process identifier type wider than the standard C integer type.

- Issue #4066: smtplib.SMTP_SSL._get_socket now correctly returns the socket.

Patch by Farhan Ahmad, test by Marcin Bachry.

- Issue #2116: Weak references and weak dictionaries now support copy()ing and

deepcopy()ing.

- Issue #1655: Make imaplib IPv6-capable. Patch by Derek Morr.

- Issue #5918: Fix a crash in the parser module.

- Issue #1664: Make nntplib IPv6-capable. Patch by Derek Morr.

- Issue #5006: Better handling of unicode byte-order marks (BOM) in the io

library. This means, for example, that opening an UTF-16 text file in

append mode doesn't add a BOM at the end of the file if the file isn't

empty.

- Issue #4050: inspect.findsource/getsource now raise an IOError if the 'source'

file is a binary. Patch by Brodie Rao, tests by Daniel Diniz. This fix

corrects a pydoc regression.

- Issue 5955: aifc's close method did not close the file it wrapped,

now it does. This also means getfp method now returns the real fp.

Installation

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

- Issue #6047: fullinstall has been removed because Python 3's executable will

now be known as python3.

- Lib/smtpd.py is no longer installed as a script.

Extension Modules

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

- Issue #3061: Use wcsftime for time.strftime where available.

- Issue #4873: Fix resource leaks in error cases of pwd and grp.

- Issue #6093: Fix off-by-one error in locale.strxfrm.

- The _functools and _locale modules are now built into the libpython shared

library instead of as extension modules.

Build

-----

- Issue #3585: Add pkg-config support. It creates a python-2.7.pc file

and a python3.pc symlink in the $(LIBDIR)/pkgconfig directory. Patch by

Clinton Roy.

Tests

-----

- Issue 5442: Tests for importlib were not properly skipping case-sensitivity

tests on darwin even when the OS was installed on a case-sensitive

filesystem. Also fixed tests that should not be run when

sys.dont_write_bytecode is true.

What's New in Python 3.1 beta 1?

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

*Release date: 2009-05-06*

Core and Builtins

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

- Issue #5914: Add new C API function PyOS_string_to_double, and

deprecate PyOS_ascii_strtod and PyOS_ascii_atof.

- Issue #3382: float.__format__, complex.__format__, and %-formatting

no longer map 'F' to 'f'. Because of issue #5859 (below), this only

affects nan -> NAN and inf -> INF.

- Issue #5799: ntpath (ie, os.path on Windows) fully supports UNC pathnames

in all operations, including splitdrive, split, etc. splitunc() now issues

a PendingDeprecation warning.

- Issue #5920: For float.__format__, change the behavior with the

empty presentation type (that is, not one of 'e', 'f', 'g', or 'n')

to be like 'g' but with at least one decimal point and with a

default precision of 12. Previously, the behavior the same but with

a default precision of 6. This more closely matches str(), and

reduces surprises when adding alignment flags to the empty

presentation type. This also affects the new complex.__format__ in

the same way.

- Implement PEP 383, Non-decodable Bytes in System Character Interfaces.

- Issue #5890: in subclasses of 'property' the __doc__ attribute was

shadowed by classtype's, even if it was None. property now

inserts the __doc__ into the subclass instance __dict__.

- Issue #4426: The UTF-7 decoder was too strict and didn't accept some legal

sequences. Patch by Nick Barnes and Victor Stinner.

- Issue #3672: Reject surrogates in utf-8 codec; add surrogatepass error handler.

- Issue #5883: In the io module, the BufferedIOBase and TextIOBase ABCs have

received a new method, detach(). detach() disconnects the underlying stream

from the buffer or text IO and returns it.

- Issue #5859: Remove switch from '%f' to '%g'-style formatting for

floats with absolute value over 1e50. Also remove length

restrictions for float formatting: '%.67f' % 12.34 and '%.120e' %

12.34 no longer raise an exception.

- Issue #1588: Add complex.__format__. For example,

format(complex(1, 2./3), '.5') now produces a sensible result.

- Issue #5864: Fix empty format code formatting for floats so that it

never gives more than the requested number of significant digits.

- Issue #5793: Rationalize isdigit / isalpha / tolower, etc. Includes

new Py_ISDIGIT / Py_ISALPHA / Py_TOLOWER, etc. in pctypes.h.

- Issue #5835: Deprecate PyOS_ascii_formatd.

- Issue #4971: Fix titlecase for characters that are their own

titlecase, but not their own uppercase.

- Issue #5283: Setting __class__ in __del__ caused a segfault.

- Issue #5816: complex(repr(z)) now recovers z exactly, even when

z involves nans, infs or negative zeros.

- Issue #3166: Make int -> float conversions correctly rounded.

- Issue #1869 (and many duplicates): make round(x, n) correctly

rounded for a float x, by using the decimal <-> binary conversions

from Python/dtoa.c. As a consequence, (e.g.) round(x, 2) now

consistently agrees with format(x, '.2f').

- Issue #5787: object.__getattribute__(some_type, "__bases__") segfaulted on

some builtin types.

- Issue #5772: format(1e100, '<') produces '1e+100', not '1.0e+100'.

- Issue #5515: str.format() type 'n' combined with commas and leading

zeros no longer gives odd results with ints and floats.

- Implement PEP 378, Format Specifier for Thousands Separator, for

floats.

- The str function switches to exponential notation at

1e11, not 1e12. This avoids printing 13 significant digits in

situations where only 12 of them are correct. Example problem

value: str(1e11 + 0.5). (This minor issue has existed in 2.x for a

long time.)

- Issue #1580: On most platforms, use a 'short' float repr: for a

finite float x, repr(x) now outputs a string based on the shortest

sequence of decimal digits that rounds to x. Previous behaviour was

to output 17 significant digits and then strip trailing zeros.

Another minor difference is that the new repr switches to

exponential notation at 1e16 instead of the previous 1e17; this

avoids misleading output in some cases.

There's a new sys attribute sys.float_repr_style, which takes

the value 'short' to indicate that we're using short float repr,

and 'legacy' if the short float repr isn't available for one

reason or another.

The float repr change involves incorporating David Gay's 'perfect

rounding' code into the Python core (it's in Python/dtoa.c). As a

secondary consequence, all string-to-float and float-to-string

conversions (including all float formatting operations) will be

correctly rounded on these platforms.

See issue 1580 discussions for details of platforms for which

this change does not apply.

- Issue #5759: float() didn't call __float__ on str subclasses.

- The string.maketrans() function is deprecated; there is a new static method

maketrans() on the bytes and bytearray classes. This removes confusion about

the types string.maketrans() is supposed to work with, and mirrors the

methods available on the str class.

- Issue #2170: refactored xml.dom.minidom.normalize, increasing both

its clarity and its speed.

- Issue #1113244: Py_XINCREF, Py_DECREF, Py_XDECREF: Add `do { ... } while (0)'

to avoid compiler warnings.

- Issue #3739: The unicode-internal encoder now reports the number of characters