+++++++++++

Python News

+++++++++++

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

What's New in Python 3.1.2?

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

*Release date: 20xx-xx-xx*

Core and Builtins

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

- 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 #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.

Extension Modules

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

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

Build

-----

- Issue #6802: Fix build issues on MacOSX 10.6

- Issue #6801 : symmetric_difference_update also accepts |.

Thanks to Carl Chenet.

Documentation

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

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

for Windows.

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

consumed like any other encoder (instead of the number of bytes).

Installation

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

- Issue #5756: Install idle and pydoc with a 3 suffix.

Library

-------

- Issue #5311: bdist_msi can now build packages that do not depend on a

specific Python version.

- Issue #5150: IDLE's format menu now has an option to strip trailing

whitespace.

- Issue #5940: distutils.command.build_clib.check_library_list was not doing

the right type checkings anymore.

- Issue #4875: On win32, ctypes.util.find_library does no longer

return directories.

- Issue #5142: Add the ability to skip modules while stepping to pdb.

- Issue #1309567: Fix linecache behavior of stripping subdirectories when

looking for files given by a relative filename.

- Issue #5923: Update the ``turtle`` module to version 1.1, add two new

turtle demos in Demo/turtle.

- Issue #5692: In :class:`zipfile.Zipfile`, fix wrong path calculation when

extracting a file to the root directory.

- Issue #5913: os.listdir() should fail for empty path on windows.

- Issue #5084: unpickling now interns the attribute names of pickled objects,

saving memory and avoiding growth in size of subsequent pickles. Proposal

and original patch by Jake McGuire.

- The json module now works exclusively with str and not bytes.

- Issue #3959: The ipaddr module has been added to the standard library.

Contributed by Google.

- Issue #3002: ``shutil.copyfile()`` and ``shutil.copytree()`` now raise an

error when a named pipe is encountered, rather than blocking infinitely.

- Issue #5857: tokenize.tokenize() now returns named tuples.

- Issue #4305: ctypes should now build again on mipsel-linux-gnu

- Issue #1734234: Massively speedup ``unicodedata.normalize()`` when the

string is already in normalized form, by performing a quick check beforehand.

Original patch by Rauli Ruohonen.

- Issue #5853: calling a function of the mimetypes module from several threads

at once could hit the recursion limit if the mimetypes database hadn't been

initialized before.

- Issue #5854: Updated __all__ to include some missing names and remove some

names which should not be exported.

- Issue #3102: All global symbols that the _ctypes extension defines

are now prefixed with 'Py' or '_ctypes'.

- Issue #5041: ctypes does now allow pickling wide character.

- Issue #5812: For the two-argument form of the Fraction constructor,

Fraction(m, n), m and n are permitted to be arbitrary Rational

instances.

- Issue #5812: Fraction('1e6') is valid: more generally, any string

that's valid for float() is now valid for Fraction(), with the

exception of strings representing NaNs and infinities.

- Issue #5734: BufferedRWPair was poorly tested and had several glaring

bugs. Patch by Brian Quinlan.

- Issue #1161031: fix readwrite select flag handling: POLLPRI now

results in a handle_expt_event call, not handle_read_event, and POLLERR

and POLLNVAL now call handle_close, not handle_expt_event. Also,

dispatcher now has an 'ignore_log_types' attribute for suppressing

log messages, which is set to 'warning' by default.

- Issue #2703: SimpleXMLRPCDispatcher.__init__: Provide default values for

new arguments introduced in 2.5.

- Issue #5828 (Invalid behavior of unicode.lower): Fixed bogus logic in

makeunicodedata.py and regenerated the Unicode database (This fixes

u'\u1d79'.lower() == '\x00').

Extension Modules

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

- Issue #5881: Remove old undocumented compatibility interfaces in hashlib and

pwd.

- Issue #5463: In struct module, remove deprecated float coercion

for integer type codes: struct.pack('L', 0.3) should now raise

an error. The _PY_STRUCT_FLOAT_COERCE constant has been removed.

The version number has been bumped to 0.3.

- Issue #5359: Readd the Berkley-DB detection code to allow _dbm be built

using Berkley-DB.

Tests

-----

- Issue #5354: New test support function import_fresh_module() makes

it easy to import both normal and optimised versions of modules.

test_heapq and test_warnings have been adjusted to use it, tests for

other modules with both C and Python implementations in the stdlib

can be adjusted to use it over time.

- Issue #5837: Certain sequences of calls to set() and unset() for

support.EnvironmentVarGuard objects restored the environment variables

incorrectly on __exit__.

C-API

-----

- Issue #5630: A replacement PyCObject API, PyCapsule, has been added.

What's New in Python 3.1 alpha 2?

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

*Release date: 2009-4-4*

Core and Builtins

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

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

integers.

- Issue #5666: Py_BuildValue's 'c' code should create byte strings.

- Issue #5499: The 'c' code for argument parsing functions now only accepts a

byte, and the 'C' code only accepts a unicode character.

- Fix a problem in PyErr_NormalizeException that leads to "undetected errors"

when hitting the recursion limit under certain circumstances.

- Issue #1665206: Remove the last eager import in _warnings.c and make it lazy.

- Fix a segfault when running test_exceptions with coverage, caused by

insufficient checks in accessors of Exception.__context__.

- Issue #5604: non-ASCII characters in module name passed to

imp.find_module() were converted to UTF-8 while the path is

converted to the default filesystem encoding, causing nonsense.

- Issue #5126: str.isprintable() returned False for space characters.

- Issue #4865: On MacOSX /Library/Python/2.7/site-packages is added to

the end sys.path, for compatibility with the system install of Python.

- Issue #4688: Add a heuristic so that tuples and dicts containing only

untrackable objects are not tracked by the garbage collector. This can

reduce the size of collections and therefore the garbage collection overhead

on long-running programs, depending on their particular use of datatypes.

- Issue #5512: Rewrite PyLong long division algorithm (x_divrem) to

improve its performance. Long divisions and remainder operations

are now between 50% and 150% faster.

- Issue #4258: Make it possible to use base 2**30 instead of base

2**15 for the internal representation of integers, for performance

reasons. Base 2**30 is enabled by default on 64-bit machines. Add

--enable-big-digits option to configure, which overrides the

default. Add sys.int_info structseq to provide information about

the internal format.

- Issue #4474: PyUnicode_FromWideChar now converts characters outside

the BMP to surrogate pairs, on systems with sizeof(wchar_t) == 4

and sizeof(Py_UNICODE) == 2.

- Issue #5237: Allow auto-numbered fields in str.format(). For

example: '{} {}'.format(1, 2) == '1 2'.

- Issue #5392: when a very low recursion limit was set, the interpreter would

abort with a fatal error after the recursion limit was hit twice.

- Issue #3845: In PyRun_SimpleFileExFlags avoid invalid memory access with

short file names.

Library

-------

- Issue #2625: added missing items() call to the for loop in

mailbox.MH.get_message().

- Issue #5640: Fix _multibytecodec so that CJK codecs don't repeat

error substitutions from non-strict codec error callbacks in

incrementalencoder and StreamWriter.

- Issue #5656: Fix the coverage reporting when running the test suite with

the -T argument.

- Issue #5647: MutableSet.__iand__() no longer mutates self during iteration.

- Issue #5624: Fix the _winreg module name still used in several modules.

- Issue #5628: Fix io.TextIOWrapper.read() with a unreadable buffer.

- Issue #5619: Multiprocessing children disobey the debug flag and causes

popups on windows buildbots. Patch applied to work around this issue.

- Issue #5400: Added patch for multiprocessing on netbsd compilation/support

- Issue #5387: Fixed mmap.move crash by integer overflow.

- Issue #5261: Patch multiprocessing's semaphore.c to support context

manager use: "with multiprocessing.Lock()" works now.

- Issue #5236: Change time.strptime() to only take strings. Didn't work with

bytes already but the failure was non-obvious.

- Issue #5177: Multiprocessing's SocketListener class now uses

socket.SO_REUSEADDR on all connections so that the user no longer needs

to wait 120 seconds for the socket to expire.

- Issue #5595: Fix UnboundedLocalError in ntpath.ismount().

- Issue #1174606: Calling read() without arguments of an unbounded file

(typically /dev/zero under Unix) could crash the interpreter.

- The max_buffer_size arguments of io.BufferedWriter, io.BufferedRWPair, and

io.BufferedRandom have been deprecated for removal in Python 3.2.

- Issue #5068: Fixed the tarfile._BZ2Proxy.read() method that would loop

forever on incomplete input. That caused tarfile.open() to hang when used

with mode 'r' or 'r:bz2' and a fileobj argument that contained no data or

partial bzip2 compressed data.

- Issue #2110: Add support for thousands separator and 'n' type

specifier to Decimal.__format__

- Fix Decimal.__format__ bug that swapped the meanings of the '<' and

'>' alignment characters.

- The error detection code in FileIO.close() could fail to reflect the `errno`

value, and report it as -1 instead.

- Issue #5016: FileIO.seekable() could return False if the file position

was negative when truncated to a C int. Patch by Victor Stinner.

Extension Modules

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

- Issue #5391: mmap now deals exclusively with bytes.

- Issue #5463: In struct module, remove deprecated overflow wrapping

when packing an integer: struct.pack('=L', -1) now raises

struct.error instead of returning b'\xff\xff\xff\xff'. The

_PY_STRUCT_RANGE_CHECKING and _PY_STRUCT_OVERFLOW_MASKING constants

have been removed from the struct module.

What's New in Python 3.1 alpha 1

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

*Release date: 2009-03-07*

Core and Builtins

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

- The io module has been reimplemented in C for speed.

- Give dict views an informative __repr__.

- Issue #5247: Improve error message when unknown format codes are

used when using str.format() with str, int, and float arguments.

- Issue #5249: time.strftime returned malformed string when format string

contained non ascii character on windows.

- Issue #4626: compile(), exec(), and eval() ignore the coding cookie if the

source has already been decoded into str.

- Issue #5186: Reduce hash collisions for objects with no __hash__ method by

rotating the object pointer by 4 bits to the right.

- Issue #4575: Fix Py_IS_INFINITY macro to work correctly on x87 FPUs:

it now forces its argument to double before testing for infinity.

- Issue #5137: Make len() correctly raise a TypeError when a __len__ method

returns a non-number type.

- Issue #5182: Removed memoryview.__str__.

- Issue #1717: Removed builtin cmp() function, dropped tp_compare

slot, the C API functions PyObject_Compare and PyUnicode_Compare and

the type definition cmpfunc. The tp_compare slot has been renamed

to tp_reserved, and is reserved for future usage.

- Issue #1242657: the __len__() and __length_hint__() calls in several tools

were suppressing all exceptions. These include list() and bytearray().

- Issue #4707: round(x, n) now returns an integer if x is an integer.

Previously it returned a float.

- Issue #4753: By enabling a configure option named '--with-computed-gotos'

on compilers that support it (notably: gcc, SunPro, icc), the bytecode

evaluation loop is compiled with a new dispatch mechanism which gives

speedups of up to 20%, depending on the system, on various benchmarks.

- Issue #4874: Most builtin decoders now reject unicode input.

- Issue #4842: Don't allow trailing 'L' when constructing an integer

from a string.

- Issue #4991: os.fdopen now raises an OSError for invalid file descriptors.

- Issue #4838: When a module is deallocated, free the memory backing the

optional module state data.

- Issue #4910: Rename nb_long slot to nb_reserved, and change its

type to (void *).

- Issue #4935: The overflow checking code in the expandtabs() method common

to str, bytes and bytearray could be optimized away by the compiler, letting

the interpreter segfault instead of raising an error.

- Issue #3720: Fix a crash when an iterator modifies its class and removes its

__next__ method.

- Issue #4910: Builtin int() function and PyNumber_Long/PyNumber_Int API

function no longer attempt to call the __long__ slot to convert an object

to an integer. Only the __int__ and __trunc__ slots are examined.

- Issue #4893: Use NT threading on CE.

- Issue #4915: Port sysmodule to Windows CE.

- Issue #4868: utf-8, utf-16 and latin1 decoding are now 2x to 4x faster. The

common cases are optimized thanks to a dedicated fast path and a moderate

amount of loop unrolling.

- Issue #4074: Change the criteria for doing a full garbage collection (i.e.

collecting the oldest generation) so that allocating lots of objects without

destroying them does not show quadratic performance. Based on a proposal by

Martin von Löwis at

http://mail.python.org/pipermail/python-dev/2008-June/080579.html.

- Issue #4604: Some objects of the I/O library could still be used after

having been closed (for instance, a read() call could return some

previously buffered data). Patch by Dmitry Vasiliev.

- Issue #4705: Fix the -u ("unbuffered binary stdout and stderr") command-line

flag to work properly. Furthermore, when specifying -u, the text stdout

and stderr streams have line-by-line buffering enabled (the default being

to buffer arbitrary chunks of data).

- The internal table, _PyLong_DigitValue, is now an array of unsigned chars

instead of ints (reducing its size from 4 to 8 times thereby reducing

Python's overall memory).

- Issue #1180193: When importing a module from a .pyc (or .pyo) file with

an existing .py counterpart, override the co_filename attributes of all

code objects if the original filename is obsolete (which can happen if the

file has been renamed, moved, or if it is accessed through different paths).

Patch by Ziga Seilnacht and Jean-Paul Calderone.

- Issue #4580: Fix slicing of memoryviews when the item size is greater than

one byte. Also fixes the meaning of len() so that it returns the number of

items, rather than the size in bytes.

- Issue #4075: Use OutputDebugStringW in Py_FatalError.

- Issue #4747: When the terminal does not use utf-8, executing a script with

non-ascii characters in its name could fail with a "SyntaxError: None" error.

- Issue #4797: IOError.filename was not set when _fileio.FileIO failed to open

file with `bytes' filename on Windows.

- Issue #3680: Reference cycles created through a dict, set or deque iterator

did not get collected.

- Issue #4701: PyObject_Hash now implicitly calls PyType_Ready on types

where the tp_hash and tp_dict slots are both NULL.

- Issue #4759: None is now allowed as the first argument of

bytearray.translate(). It was always allowed for bytes.translate().

- Added test case to ensure attempts to read from a file opened for writing

fail.

- Issue #3106: Speedup some comparisons (str/str and int/int).

- Issue #2183: Simplify and optimize bytecode for list, dict and set

comprehensions. Original patch for list comprehensions by Neal Norwitz.

- Issue #2467: gc.DEBUG_STATS reported invalid elapsed times. Also, always

print elapsed times, not only when some objects are uncollectable /

unreachable. Original patch by Neil Schemenauer.

- Issue #3439: Add a bit_length method to int.

- Issue #2173: When getting device encoding, check that return value of

nl_langinfo is not the empty string. This was causing silent build

failures on OS X.

- Issue #4597: Fixed several opcodes that weren't always propagating

exceptions.

- Issue #4589: Fixed exception handling when the __exit__ function of a

context manager returns a value that cannot be converted to a bool.

- Issue #4445: Replace "sizeof(PyBytesObject)" with

"offsetof(PyBytesObject, ob_sval) + 1" when allocating memory for

bytes instances. On a typical machine this saves 3 bytes of memory

(on average) per allocation of a bytes instance.

- Issue #4533: File read operation was dreadfully slow due to a slowly

growing read buffer. Fixed by using the same growth rate algorithm as

Python 2.x.

- Issue #4509: Various issues surrounding resize of bytearray objects to

which there are buffer exports (e.g. memoryview instances).

- Issue #4233: Changed semantic of ``_fileio.FileIO``'s ``close()``

method on file objects with closefd=False. The file descriptor is still

kept open but the file object behaves like a closed file. The ``FileIO``

object also got a new readonly attribute ``closefd``.