++++++++++++++++++++++++++
Python 2.4.2 Release Notes
++++++++++++++++++++++++++
What's New in Python 2.4.2 final?
=================================
*Release date: 28-SEP-2005*
Extension Modules
-----------------
- Patches #1298449 and #1298499: Add some missing checks for error
returns in cStringIO.c.
- Patch #1297028: fix segfault if call type on MultibyteCodec,
MultibyteStreamReader, or MultibyteStreamWriter.
Tests
-----
- Fixed failure in test_macfs on Mac OS X 10.4 (Tiger), which
apparently doesn't allow the creation time to be set later than the
modification time. Fixed by changing the test data.
Build
-----
- The Windows .msi files are now compressed using lzx:21. This produces a
significantly smaller installer.
What's New in Python 2.4.2c1
============================
*Release date: 21-SEP-2005*
Core and builtins
-----------------
- On 64-bit platforms, when __len__() returns a value that cannot be
represented as a C int, raise OverflowError.
- SF bug #893549: parsing keyword arguments was broken with a few format
codes.
- Changes donated by Elemental Security to make it work on AIX 5.3
with IBM's 64-bit compiler (SF patch #1284289). This also closes SF
bug #105470: test_pwd fails on 64bit system (Opteron).
- Changes donated by Elemental Security to make it work on HP-UX 11 on
Itanium2 with HP's 64-bit compiler (SF patch #1225212).
- Disallow keyword arguments for type constructors that don't use them
(fixes bug #1119418).
- Forward UnicodeDecodeError into SyntaxError for source encoding errors.
- SF bug #900092: When tracing (e.g. for hotshot), restore 'return' events for
exceptions that cause a function to exit.
- SF bug #1257731: set.discard() and set.remove() did not correctly
handle keys that both inherited from set and defined their own
__hash__() function. Also, changed set.__contains__() to have
identical logic.
- The set() builtin can now properly compute s-=s as an empty set.
- SF bug #1238681: freed pointer is used in longobject.c:long_pow().
- SF bug #1185883: Python's small-object memory allocator took over
a block managed by the platform C library whenever a realloc specified
a small new size. However, there's no portable way to know then how
much of the address space following the pointer is valid, so no
portable way to copy data from the C-managed block into Python's
small-object space without risking a memory fault. Python's small-object
realloc now leaves such blocks under the control of the platform C
realloc.
- Fix garbage collection for set and frozenset objects. SF patch #1200018.
- It is now safe to call PyGILState_Release() before
PyEval_InitThreads() (note that if there is reason to believe there
are multiple threads around you still must call PyEval_InitThreads()
before using the Python API; this fix is for extension modules that
have no way of knowing if Python is multi-threaded yet).
- Typing Ctrl-C whilst raw_input() was waiting in a build with threads
disabled caused a crash.
- Bug #1165306: instancemethod_new allowed the creation of a method
with im_class == im_self == NULL, which caused a crash when called.
Extension Modules
-----------------
- Fix memory leak in posix.access().
- Patch #1213831: Fix typo in unicodedata._getcode.
- Bug #1007046: os.startfile() did not accept unicode strings encoded in
the file system encoding.
- Patch #756021: Special-case socket.inet_aton('255.255.255.255') for
platforms that don't have inet_aton().
- Bug #1215928: Fix bz2.BZ2File.seek() for 64-bit file offsets.
- Bug #1191043: Fix bz2.BZ2File.(x)readlines() for files containing one line
without newlines.
- Bug #728515: mmap.resize() now resizes the file on Unix as it did
on Windows.
- Bug #1234979: For the argument of thread.Lock.acquire, the Windows
implemented treated all integer values except 1 as false.
- Bug #1194181: bz2.BZ2File didn't handle mode 'U' correctly.
- Bug #1166660: The readline module could segfault if hook functions
were set in a different thread than that which called readline.
- weakref proxy has incorrect __nonzero__ behavior. SF bug #1770766.
Library
-------
- Patch #1166948: locale.py: Prefer LC_ALL, LC_CTYPE and LANG over LANGUAGE
to get the correct encoding.
- Patch #1166938: locale.py: Parse LANGUAGE as a colon separated list of
languages.
- Patch #1268314: Cache lines in StreamReader.readlines for performance.
- Bug #1290505: time.strptime() was not invalidating its regex cache when the
locale changed.
- Fix a misuse of str.find() in detection of use of %U or %W in datetime
format.
- Bug #1167128: Fix size of a symlink in a tarfile to be 0.
- Patch #810023: Fix off-by-one bug in urllib.urlretrieve reporthook
functionality.
- Bug #1163178: Make IDNA return an empty string when the input is empty.
- Bug #1121494: distutils.dir_utils.mkpath now accepts Unicode strings.
- Bug #1178484: Return complete lines from codec stream readers
even if there is an exception in later lines, resulting in
correct line numbers for decoding errors in source code.
- Bug #1266283: "lexists" is now in os.path.__all__.
- The sets module can now properly compute s-=s and s^=s as an empty set.
- Bug #1192315: Disallow negative arguments to clear() in pdb.
- Patch #827386: Support absolute source paths in msvccompiler.py.
- Fix a problem in Tkinter introduced by SF patch #869468: delete bogus
__hasattr__ and __delattr__ methods on class Tk that were breaking
Tkdnd.
- Bug #1015140: disambiguated the term "article id" in nntplib docs and
docstrings to either "article number" or "message id".
- Bug #1177468: Don't cache the /dev/urandom file descriptor for os.urandom,
as this can cause problems with apps closing all file descriptors.
- Bug #839151: Fix an attempt to access sys.argv in the warnings module
though this can be missing in embedded interpreters
- Bug #1155638: Fix a bug which affected HTTP 0.9 responses in httplib.
- Bug #1100201: Cross-site scripting was possible on BaseHTTPServer via
error messages.
- Bug #1224621: tokenize module does not detect inconsistent dedents
- Bug #1196315: fix weakref.WeakValueDictionary constructor.
- Bug #1213894: os.path.realpath didn't resolve symlinks that were the first
component of the path.
- distutils.commands.register now encodes the data as UTF-8 before posting
them to PyPI.
- Partial fixes for SF bugs #1163244 and #1175396: If a chunk read by
``codecs.StreamReader.readline()`` has a trailing "\r", read one more
character even if the user has passed a size parameter to get a proper
line ending. Remove the special handling of a "\r\n" that has been split
between two lines.
- Bug #1251300: On UCS-4 builds the "unicode-internal" codec will now complain
about illegal code points. The codec now supports PEP 293 style error
handlers.
- Bug #1235646: ``codecs.StreamRecoder.next()`` now reencodes the data it reads
from the input stream, so that the output is a byte string in the correct
encoding instead of a unicode string.
- Bug #1202493: Fixing SRE parser to handle '{}' as perl does, rather than
considering it exactly like a '*'.
Build
-----
- Patch #1160164: Build zlib.pyd for Itanium.
- Bug #1189330: configure did not correctly determine the necessary
value of LINKCC if python was built with GCC 4.0.
- Upgrade Windows build to zlib 1.2.3 which eliminates a potential security
vulnerability in zlib 1.2.1 and 1.2.2.
Documentation
-------------
- Bug #1274828: Document os.path.splitunc().
- Bug #1190204: Clarify which directories are searched by site.py.
- Bug #1193849: Clarify os.path.expanduser() documentation.
- Bug #1243192: re.UNICODE and re.LOCALE affect \d, \D, \s and \S.
- Bug #755617: Document the effects of os.chown() on Windows.
- Patch #1180012: The documentation for modulefinder is now in the library reference.
- Patch #1213031: Document that os.chown() accepts argument values of -1.
- Bug #1190563: Document os.waitpid() return value with WNOHANG flag.
- Bug #1175022: Correct the example code for property().
Tools/Demos
-----------
- Bug #1072853: pindent.py used an uninitialized variable.
What's New in Python 2.4.1 final?
=================================
*Release date: 30-MAR-2005*
Core and builtins
-----------------
- Move exception finalisation later in the shutdown process - this
fixes the crash seen in bug #1165761
Tests
-----
- SF patch 1167316: doctest.py fails self-test if run directly.
Build
-----
- SF patch 1171767: Darwin 8's headers are anal about POSIX compliance,
and linking has changed (prebinding is now deprecated, and libcc_dynamic
no longer exists). This configure patch makes things right.
What's New in Python 2.4.1c2?
=============================
*Release date: 17-MAR-2005*
Library
-------
- Fixed decimal operator and comparison methods to return NotImplemented
instead of raising a TypeError when interacting with other types.
Allows other classes to successfully implement __radd__ style methods.
- Bug #1163325: Decimal infinities failed to hash. Attempting to
hash a NaN raised an InvalidOperation instead of a TypeError.
- Bug #1160802: can't build Zope on Windows with 2.4.1c1. The
``MSVCCompiler`` class in distutils forgot to record that it was
initialized, and continued adding redundant entries to the system
``PATH`` environment variable until ``putenv()`` complained about the
size. This only affected building projects with many C extensions,
and only on Windows using Microsoft's compiler. This wasn't visible
before because a bugfix first included in 2.4.1c1 provoked it (bug
#1110478: revert os.environ.update to do putenv again).
- Bug #1156259: Seeking in codecs.reader was broken, now fixed.
Tests
-----
- Fix the test for socket.getfqdn() in test_socket to also consider the host
name returned by socket.gethostname() a valid return value for getfqdn().
Also clarified the wording of docs and docstring that this is the case.
Extensions Modules
------------------
- os.access now supports Unicode path names on non-Win32 systems.
What's New in Python 2.4.1c1?
=============================
*Release date: 10-MAR-2005*
Core and builtins
-----------------
- Bug #1155938: new style classes did not verify that __init__()
returns None.
- Bug #723201: Raise a TypeError for passing bad objects to 'L' format.
- Bug #1124295: the __name__ attribute of file objects was
inadvertently made inaccessible in restricted mode.
- Bug #1074011: closing sys.std{out,err} now causes a flush() and
an ferror() call.
- Bug #1085744: Add missing overflow check to PySequence_Tuple().
Make resize schedule linear (amortized).
- marshal.dumps() no longer crashes when the optional argument ``version``
is provided.
Extension Modules
-----------------
- Patches #925152, #1118602: Avoid reading after the end of the buffer
in pyexpat.GetInputContext.
- Patch #1093585: raise a ValueError for negative history items in readline.
{remove_history,replace_history}
Library
-------
- Patch #1075887: Don't require MSVC in distutils if there is nothing
to build.
- Patch #1103407: Properly deal with tarfile iterators when untarring
symbolic links on Windows.
- Patch #1117454: Remove code to special-case cookies without values
in LWPCookieJar.
- Patch #1117339: Add cookielib special name tests.
- Patch #1112812: Make bsddb/__init__.py more friendly for modulefinder.
- Patch #1121234: Properly cleanup _exit and tkerror commands.
- Applied a security fix to SimpleXMLRPCserver (PSF-2005-001). This
disables recursive traversal through instance attributes, which can
be exploited in various ways.
- Bug #1110478: Revert os.environ.update to do putenv again.
- Bug #1103844: fix distutils.install.dump_dirs() with negated options.
- Bug #1067732: wininst --install-script doesn't leave residual files anymore.
- StringIO.truncate() now correctly adjusts the size attribute.
(Bug #951915).
- The decimal module wouldn't run on builds without threads (Bug #1083645).
- Bug #1086555: Fix leak in syslog module.
- atexit.register no longer references the sys module before importing it.
(Bug #1083202).
- unittest.TestCase.run() and unittest.TestSuite.run() can now be successfully
extended or overridden by subclasses. Formerly, the subclassed method would
be ignored by the rest of the module. (Bug #1078905).
- Bug #1076985: ``codecs.StreamReader.readline()`` now calls ``read()`` only
once when a size argument is given. This prevents a buffer overflow in the
tokenizer with very long source lines.
- Bug #1083110: ``zlib.decompress.flush()`` would segfault if called immediately
after creating the object, without any intervening ``.decompress()`` calls.
- Bug #1149508: ``textwrap`` now handles hyphenated numbers (eg. "2004-03-05")
correctly.
Build
-----
- Bug #1158607: Build with --disable-unicode again.
- term.h is now properly detected again.
- Check for tzset no longer dependent on tm->tm_zone to exist in the struct
(not required by either ISO C nor the UNIX 2 spec).
Tests for sanity in tzname when HAVE_TZNAME defined were also defined.
Closes bug #1096244. Thanks Gregory Bond.
Windows
-------
- Bug #1076861: The IDLE shortcut is now correct even if the target
directory contains a space.
- Bug #1085208 and similar: The installer does not fail anymore if
VBScript is not available on the target machine, not installed
properly, or outdated; the MSI package now does not rely on VB
anymore.
Macintosh
---------
- Bug #1091468: make frameworkinstall now works with DESTROOT builds
- On 10.3 and later extensions are built with -undefined dynamic_lookup.
This ensures that extensions can be built in older versions of Python after
a newer framework has been installed. In addition, an extension will not
accidentally pull in another copy of the Python interpreter.
On 10.2 and earlier (or if MACOSX_DEPLOYMENT_TARGET is set to a value <= 10.2)
extensions are linked directly to the dylib in the framework, in stead
of against the framework itself. This ensures that extensions can be built
in older versions of Python after a newer framework has been installed.
- PackageManager and the underlying pimp.py module have been updated to
version 0.5, which greatly simplifies maintainance of the package
databases.
Documentation
-------------
- Remove all latent references for "Macintosh" that referred to semantics for
Mac OS 9 and change to reflect the state for OS X.
Closes patch #1095802. Thanks Jack Jansen.
What's New in Python 2.4 final?
===============================
*Release date: 30-NOV-2004*
Core and builtins
-----------------
- Bug 875692: Improve signal handling, especially when using threads, by
forcing an early re-execution of PyEval_EvalFrame() "periodic" code when
things_to_do is not cleared by Py_MakePendingCalls().
What's New in Python 2.4 (release candidate 1)
==============================================
*Release date: 18-NOV-2004*
Core and builtins
-----------------
- Bug 1061968: Fixes in 2.4a3 to address thread bug 1010677 reintroduced
the years-old thread shutdown race bug 225673. Numeric history lesson
aside, all bugs in all three reports are fixed now.
Library
-------
- Bug 1052242: If exceptions are raised by an atexit handler function an
attempt is made to execute the remaining handlers. The last exception
raised is re-raised.
- ``doctest``'s new support for adding ``pdb.set_trace()`` calls to
doctests was broken in a dramatic but shallow way. Fixed.
- Bug 1065388: ``calendar``'s ``day_name``, ``day_abbr``, ``month_name``,
and ``month_abbr`` attributes emulate sequences of locale-correct
spellings of month and day names. Because the locale can change at
any time, the correct spelling is recomputed whenever one of these is
indexed. In the worst case, the index may be a slice object, so these
recomputed every day or month name each time they were indexed. This is
much slower than necessary in the usual case, when the index is just an
integer. In that case, only the single spelling needed is recomputed
now; and, when the index is a slice object, only the spellings needed
by the slice are recomputed now.
- Patch 1061679: Added ``__all__`` to pickletools.py.
Build
-----
- Bug 1034277 / Patch 1035255: Remove compilation of core against CoreServices
and CoreFoundation on OS X. Involved removing PyMac_GetAppletScriptFile()
which has no known users. Thanks Bob Ippolito.
C API
-----
- The PyRange_New() function is deprecated.
What's New in Python 2.4 beta 2?
================================
*Release date: 03-NOV-2004*
License
-------
The Python Software Foundation changed the license under which Python
is released, to remove Python version numbers. There were no other
changes to the license. So, for example, wherever the license for
Python 2.3 said "Python 2.3", the new license says "Python". The
intent is to make it possible to refer to the PSF license in a more
durable way. For example, some people say they're confused by that
the Open Source Initiative's entry for the Python Software Foundation
License::
http://www.opensource.org/licenses/PythonSoftFoundation.php
says "Python 2.1.1" all over it, wondering whether it applies only
to Python 2.1.1.
The official name of the new license is the Python Software Foundation
License Version 2.
Core and builtins
-----------------
- Bug #1055820 Cyclic garbage collection was not protecting against that
calling a live weakref to a piece of cyclic trash could resurrect an
insane mutation of the trash if any Python code ran during gc (via
running a dead object's __del__ method, running another callback on a
weakref to a dead object, or via any Python code run in any other thread
that managed to obtain the GIL while a __del__ or callback was running
in the thread doing gc). The most likely symptom was "impossible"
``AttributeEror`` exceptions, appearing seemingly at random, on weakly
referenced objects. The cure was to clear all weakrefs to unreachable
objects before allowing any callbacks to run.
- Bug #1054139 _PyString_Resize() now invalidates its cached hash value.
Extension Modules
-----------------
- Bug #1048870: the compiler now generates distinct code objects for
functions with identical bodies. This was producing confusing
traceback messages which pointed to the function where the code
object was first defined rather than the function being executed.
Library
-------
- Patch #1056967 changes the semantics of Template.safe_substitute() so that
no ValueError is raised on an 'invalid' match group. Now the delimiter is
returned.
- Bug #1052503 pdb.runcall() was not passing along keyword arguments.
- Bug #902037: XML.sax.saxutils.prepare_input_source() now combines relative
paths with a base path before checking os.path.isfile().
- The whichdb module can now be run from the command line.
- Bug #1045381: time.strptime() can now infer the date using %U or %W (week of
the year) when the day of the week and year are also specified.
- Bug #1048816: fix bug in Ctrl-K at start of line in curses.textpad.Textbox
- Bug #1017553: fix bug in tarfile.filemode()
- Patch #737473: fix bug that old source code is shown in tracebacks even if
the source code is updated and reloaded.
Build
-----
- Patch #1044395: --enable-shared is allowed in FreeBSD also.
What's New in Python 2.4 beta 1?
================================
*Release date: 15-OCT-2004*
Core and builtins
-----------------
- Patch #975056: Restartable signals were not correctly disabled on
BSD systems. Consistently use PyOS_setsig() instead of signal().
- The internal portable implementation of thread-local storage (TLS), used
by the ``PyGILState_Ensure()``/``PyGILState_Release()`` API, was not
thread-correct. This could lead to a variety of problems, up to and
including segfaults. See bug 1041645 for an example.
- Added a command line option, -m module, which searches sys.path for the
module and then runs it. (Contributed by Nick Coghlan.)
- The bytecode optimizer now folds tuples of constants into a single
constant.
- SF bug #513866: Float/long comparison anomaly. Prior to 2.4b1, when
an integer was compared to a float, the integer was coerced to a float.
That could yield spurious overflow errors (if the integer was very
large), and to anomalies such as
``long(1e200)+1 == 1e200 == long(1e200)-1``. Coercion to float is no
longer performed, and cases like ``long(1e200)-1 < 1e200``,
``long(1e200)+1 > 1e200`` and ``(1 << 20000) > 1e200`` are computed
correctly now.
Extension modules
-----------------
- ``collections.deque`` objects didn't play quite right with garbage
collection, which could lead to a segfault in a release build, or
an assert failure in a debug build. Also, added overflow checks,
better detection of mutation during iteration, and shielded deque
comparisons from unusual subclass overrides of the __iter__() method.
Library
-------
- Patch 1046644: distutils build_ext grew two new options - --swig for
specifying the swig executable to use, and --swig-opts to specify
options to pass to swig. --swig-opts="-c++" is the new way to spell
--swig-cpp.
- Patch 983206: distutils now obeys environment variable LDSHARED, if
it is set.
- Added Peter Astrand's subprocess.py module. See PEP 324 for details.
- time.strptime() now properly escapes timezones and all other locale-specific
strings for regex-specific symbols. Was breaking under Japanese Windows when
the timezone was specified as "Tokyo (standard time)".
Closes bug #1039270.
- Updates for the email package:
+ email.Utils.formatdate() grew a 'usegmt' argument for HTTP support.
+ All deprecated APIs that in email 2.x issued warnings have been removed:
_encoder argument to the MIMEText constructor, Message.add_payload(),
Utils.dump_address_pair(), Utils.decode(), Utils.encode()
+ New deprecations: Generator.__call__(), Message.get_type(),
Message.get_main_type(), Message.get_subtype(), the 'strict' argument to
the Parser constructor. These will be removed in email 3.1.
+ Support for Python earlier than 2.3 has been removed (see PEP 291).
+ All defect classes have been renamed to end in 'Defect'.
+ Some FeedParser fixes; also a MultipartInvariantViolationDefect will be
added to messages that claim to be multipart but really aren't.
+ Updates to documentation.
- re's findall() and finditer() functions now take an optional flags argument
just like the compile(), search(), and match() functions. Also, documented
the previously existing start and stop parameters for the findall() and
finditer() methods of regular expression objects.
- rfc822 Messages now support iterating over the headers.
- The (undocumented) tarfile.Tarfile.membernames has been removed;
applications should use the getmember function.
- httplib now offers symbolic constants for the HTTP status codes.
- SF bug #1028306: Trying to compare a ``datetime.date`` to a
``datetime.datetime`` mistakenly compared only the year, month and day.
Now it acts like a mixed-type comparison: ``False`` for ``==``,
``True`` for ``!=``, and raises ``TypeError`` for other comparison
operators. Because datetime is a subclass of date, comparing only the
base class (date) members can still be done, if that's desired, by
forcing using of the approprate date method; e.g.,
``a_date.__eq__(a_datetime)`` is true if and only if the year, month
and day members of ``a_date`` and ``a_datetime`` are equal.
- bdist_rpm now supports command line options --force-arch,
{pre,post}-install, {pre,post}-uninstall, and
{prep,build,install,clean,verify}-script.
- SF patch #998993: The UTF-8 and the UTF-16 stateful decoders now support
decoding incomplete input (when the input stream is temporarily exhausted).
``codecs.StreamReader`` now implements buffering, which enables proper
readline support for the UTF-16 decoders. ``codecs.StreamReader.read()``
has a new argument ``chars`` which specifies the number of characters to
return. ``codecs.StreamReader.readline()`` and
``codecs.StreamReader.readlines()`` have a new argument ``keepends``.
Trailing "\n"s will be stripped from the lines if ``keepends`` is false.
- The documentation for doctest is greatly expanded, and now covers all
the new public features (of which there are many).
- ``doctest.master`` was put back in, and ``doctest.testmod()`` once again
updates it. This isn't good, because every ``testmod()`` call
contributes to bloating the "hidden" state of ``doctest.master``, but
some old code apparently relies on it. For now, all we can do is
encourage people to stitch doctests together via doctest's unittest
integration features instead.
- httplib now handles ipv6 address/port pairs.
- SF bug #1017864: ConfigParser now correctly handles default keys,
processing them with ``ConfigParser.optionxform`` when supplied,
consistent with the handling of config file entries and runtime-set
options.
- SF bug #997050: Document, test, & check for non-string values in
ConfigParser. Moved the new string-only restriction added in
rev. 1.65 to the SafeConfigParser class, leaving existing
ConfigParser & RawConfigParser behavior alone, and documented the
conditions under which non-string values work.
Build
-----
- Building on darwin now includes /opt/local/include and /opt/local/lib for
building extension modules. This is so as to include software installed as
a DarwinPorts port
- pyport.h now defines a Py_IS_NAN macro. It works as-is when the
platform C computes true for ``x != x`` if and only if X is a NaN.
Other platforms can override the default definition with a platform-
specific spelling in that platform's pyconfig.h. You can also override
pyport.h's default Py_IS_INFINITY definition now.
C API
-----
- SF patch 1044089: New function ``PyEval_ThreadsInitialized()`` returns
non-zero if PyEval_InitThreads() has been called.
- The undocumented and unused extern int ``_PyThread_Started`` was removed.
- The C API calls ``PyInterpreterState_New()`` and ``PyThreadState_New()``
are two of the very few advertised as being safe to call without holding
the GIL. However, this wasn't true in a debug build, as bug 1041645
demonstrated. In a debug build, Python redirects the ``PyMem`` family
of calls to Python's small-object allocator, to get the benefit of
its extra debugging capabilities. But Python's small-object allocator
isn't threadsafe, relying on the GIL to avoid the expense of doing its
own locking. ``PyInterpreterState_New()`` and ``PyThreadState_New()``
call the platform ``malloc()`` directly now, regardless of build type.
- PyLong_AsUnsignedLong[Mask] now support int objects as well.
- SF patch #998993: ``PyUnicode_DecodeUTF8Stateful`` and
``PyUnicode_DecodeUTF16Stateful`` have been added, which implement stateful
decoding.
Tests
-----
- test__locale ported to unittest
Mac
---
- ``plistlib`` now supports non-dict root objects. There is also a new
interface for reading and writing plist files: ``readPlist(pathOrFile)``
and ``writePlist(rootObject, pathOrFile)``
Tools/Demos
-----------
- The text file comparison scripts ``ndiff.py`` and ``diff.py`` now
read the input files in universal-newline mode. This spares them
from consuming a great deal of time to deduce the useless result that,
e.g., a file with Windows line ends and a file with Linux line ends
have no lines in common.
What's New in Python 2.4 alpha 3?
=================================
*Release date: 02-SEP-2004*
Core and builtins
-----------------
- SF patch #1007189: ``from ... import ...`` statements now allow the name
list to be surrounded by parentheses.
- Some speedups for long arithmetic, thanks to Trevor Perrin. Gradeschool
multiplication was sped a little by optimizing the C code. Gradeschool
squaring was sped by about a factor of 2, by exploiting that about half
the digit products are duplicates in a square. Because exponentiation
uses squaring often, this also speeds long power. For example, the time
to compute 17**1000000 dropped from about 14 seconds to 9 on my box due
to this much. The cutoff for Karatsuba multiplication was raised,
since gradeschool multiplication got quicker, and the cutoff was
aggressively small regardless. The exponentiation algorithm was switched
from right-to-left to left-to-right, which is more efficient for small
bases. In addition, if the exponent is large, the algorithm now does
5 bits (instead of 1 bit) at a time. That cut the time to compute
17**1000000 on my box in half again, down to about 4.5 seconds.
- OverflowWarning is no longer generated. PEP 237 scheduled this to
occur in Python 2.3, but since OverflowWarning was disabled by default,
nobody realized it was still being generated. On the chance that user
code is still using them, the Python builtin OverflowWarning, and
corresponding C API PyExc_OverflowWarning, will exist until Python 2.5.
- Py_InitializeEx has been added.
- Fix the order of application of decorators. The proper order is bottom-up;
the first decorator listed is the last one called.
- SF patch #1005778. Fix a seg fault if the list size changed while
calling list.index(). This could happen if a rich comparison function
modified the list.
- The ``func_name`` (a.k.a. ``__name__``) attribute of user-defined
functions is now writable.
- code_new (a.k.a new.code()) now checks its arguments sufficiently
carefully that passing them on to PyCode_New() won't trigger calls
to Py_FatalError() or PyErr_BadInternalCall(). It is still the case
that the returned code object might be entirely insane.
- Subclasses of string can no longer be interned. The semantics of
interning were not clear here -- a subclass could be mutable, for
example -- and had bugs. Explicitly interning a subclass of string
via intern() will raise a TypeError. Internal operations that attempt
to intern a string subclass will have no effect.
- Bug 1003935: xrange() could report bogus OverflowErrors. Documented
what xrange() intends, and repaired tests accordingly.
Extension modules
-----------------
- difflib now supports HTML side-by-side diff.
- os.urandom has been added for systems that support sources of random
data.
- Patch 1012740: truncate() on a writeable cStringIO now resets the
position to the end of the stream. This is consistent with the original
StringIO module and avoids inadvertently resurrecting data that was
supposed to have been truncated away.
- Added socket.socketpair().
- Added CurrentByteIndex, CurrentColumnNumber, CurrentLineNumber
members to xml.parsers.expat.XMLParser object.
- The mpz, rotor, and xreadlines modules, all deprecated in earlier
versions of Python, have now been removed.
Library
-------
- Patch #934356: if a module defines __all__, believe that rather than using
heuristics for filtering out imported names.
- Patch #941486: added os.path.lexists(), which returns True for broken
symlinks, unlike os.path.exists().
- the random module now uses os.urandom() for seeding if it is available.
Added a new generator based on os.urandom().
- difflib and diff.py can now generate HTML.
- bdist_rpm now includes version and release in the BuildRoot, and
replaces - by ``_`` in version and release.
- distutils build/build_scripts now has an -e option to specify the
path to the Python interpreter for installed scripts.
- PEP 292 classes Template and SafeTemplate are added to the string module.
- tarfile now generates GNU tar files by default.
- HTTPResponse has now a getheaders method.
- Patch #1006219: let inspect.getsource handle '@' decorators. Thanks Simon
Percivall.
- logging.handlers.SMTPHandler.date_time has been removed;
the class now uses email.Utils.formatdate to generate the time stamp.
- A new function tkFont.nametofont was added to return an existing
font. The Font class constructor now has an additional exists argument
which, if True, requests to return/configure an existing font, rather
than creating a new one.
- Updated the decimal package's min() and max() methods to match the
latest revision of the General Decimal Arithmetic Specification.
Quiet NaNs are ignored and equal values are sorted based on sign
and exponent.
- The decimal package's Context.copy() method now returns deep copies.
- Deprecated sys.exitfunc in favor of the atexit module. The sys.exitfunc
attribute will be kept around for backwards compatibility and atexit
will just become the one preferred way to do it.
- patch #675551: Add get_history_item and replace_history_item functions
to the readline module.
- bug #989672: pdb.doc and the help messages for the help_d and help_u methods
of the pdb.Pdb class gives have been corrected. d(own) goes to a newer
frame, u(p) to an older frame, not the other way around.
- bug #990669: os.path.realpath() will resolve symlinks before normalizing the
path, as normalizing the path may alter the meaning of the path if it
contains symlinks.
- bug #851123: shutil.copyfile will raise an exception when trying to copy a
file onto a link to itself. Thanks Gregory Ball.
- bug #570300: Fix inspect to resolve file locations using os.path.realpath()
so as to properly list all functions in a module when the module itself is
reached through a symlink. Thanks Johannes Gijsbers.
- doctest refactoring continued. See the docs for details. As part of
this effort, some old and little- (never?) used features are now
deprecated: the Tester class, the module is_private() function, and the
isprivate argument to testmod(). The Tester class supplied a feeble
"by hand" way to combine multiple doctests, if you knew exactly what
you were doing. The newer doctest features for unittest integration
already did a better job of that, are stronger now than ever, and the
new DocTestRunner class is a saner foundation if you want to do it by
hand. The "private name" filtering gimmick was a mistake from the
start, and testmod() changed long ago to ignore it by default. If
you want to filter out tests, the new DocTestFinder class can be used
to return a list of all doctests, and you can filter that list by
any computable criteria before passing it to a DocTestRunner instance.
- Bug #891637, patch #1005466: fix inspect.getargs() crash on def foo((bar)).
Tools/Demos
-----------
- IDLE's shortcut keys for windows are now case insensitive so that
Control-V works the same as Control-v.
- pygettext.py: Generate POT-Creation-Date header in ISO format.
Build
-----
- Backward incompatibility: longintrepr.h now triggers a compile-time
error if SHIFT (the number of bits in a Python long "digit") isn't
divisible by 5. This new requirement allows simple code for the new
5-bits-at-a-time long_pow() implementation. If necessary, the
restriction could be removed (by complicating long_pow(), or by
falling back to the 1-bit-at-a-time algorithm), but there are no
plans to do so.
- bug #991962: When building with --disable-toolbox-glue on Darwin no
attempt to build Mac-specific modules occurs.
- The --with-tsc flag to configure to enable VM profiling with the
processor's timestamp counter now works on PPC platforms.
- patch #1006629: Define _XOPEN_SOURCE to 500 on Solaris 8/9 to match
GCC's definition and avoid redefinition warnings.
- Detect pthreads support (provided by gnu pth pthread emulation) on
GNU/k*BSD systems.
- bug #1005737, #1007249: Fixed several build problems and warnings
found on old/legacy C compilers of HP-UX, IRIX and Tru64.
C API
-----
..
Documentation
-------------
- patch #1005936, bug #1009373: fix index entries which contain
an underscore when viewed with Acrobat.
- bug #990669: os.path.normpath may alter the meaning of a path if
it contains symbolic links. This has been documented in a comment
since 1992, but is now in the library reference as well.
New platforms
-------------
- FreeBSD 6 is now supported.
Tests
-----
..
Windows
-------
- Boosted the stack reservation for python.exe and pythonw.exe from
the default 1MB to 2MB. Stack frames under VC 7.1 for 2.4 are enough
bigger than under VC 6.0 for 2.3.4 that deeply recursive progams
within the default sys.getrecursionlimit() default value of 1000 were
able to suffer undetected C stack overflows. The standard test program
test_compiler was one such program. If a Python process on Windows
"just vanishes" without a trace, and without an error message of any
kind, but with an exit code of 128, undetected stack overflow may be
the problem.
Mac
---
..
What's New in Python 2.4 alpha 2?
=================================
*Release date: 05-AUG-2004*
Core and builtins
-----------------
- Patch #980695: Implements efficient string concatenation for statements
of the form s=s+t and s+=t. This will vary across implementations.
Accordingly, the str.join() method is strongly preferred for performance
sensitive code.
- PEP-0318, Function Decorators have been added to the language. These are
implemented using the Java-style @decorator syntax, like so::
@staticmethod
def foo(bar):
(The PEP needs to be updated to reflect the current state)
- When importing a module M raises an exception, Python no longer leaves M
in sys.modules. Before 2.4a2 it did, and a subsequent import of M would
succeed, picking up a module object from sys.modules reflecting as much
of the initialization of M as completed before the exception was raised.
Subsequent imports got no indication that M was in a partially-
initialized state, and the importers could get into arbitrarily bad
trouble as a result (the M they got was in an unintended state,
arbitrarily far removed from M's author's intent). Now subsequent
imports of M will continue raising exceptions (but if, for example, the
source code for M is edited between import attempts, then perhaps later
attempts will succeed, or raise a different exception).
This can break existing code, but in such cases the code was probably
working before by accident. In the Python source, the only case of
breakage discovered was in a test accidentally relying on a damaged
module remaining in sys.modules. Cases are also known where tests
deliberately provoking import errors remove damaged modules from
sys.modules themselves, and such tests will break now if they do an
unconditional del sys.modules[M].
- u'%s' % obj will now try obj.__unicode__() first and fallback to
obj.__str__() if no __unicode__ method can be found.
- Patch #550732: Add PyArg_VaParseTupleAndKeywords(). Analogous to
PyArg_VaParse(). Both are now documented. Thanks Greg Chapman.
- Allow string and unicode return types from .encode()/.decode()
methods on string and unicode objects. Added unicode.decode()
which was missing for no apparent reason.
- An attempt to fix the mess that is Python's behaviour with
signal handlers and threads, complicated by readline's behaviour.
It's quite possible that there are still bugs here.
- Added C macros Py_CLEAR and Py_VISIT to ease the implementation of
types that support garbage collection.
- Compiler now treats None as a constant.
- The type of values returned by __int__, __float__, __long__,
__oct__, and __hex__ are now checked. Returning an invalid type
will cause a TypeError to be raised. This matches the behavior of
Jython.
- Implemented bind_textdomain_codeset() in locale module.
- Added a workaround for proper string operations in BSDs. str.split
and str.is* methods can now work correctly with UTF-8 locales.
- Bug #989185: unicode.iswide() and unicode.width() is dropped and
the East Asian Width support is moved to unicodedata extension
module.
- Patch #941229: The source code encoding in interactive mode
now refers sys.stdin.encoding not just ISO-8859-1 anymore. This
allows for non-latin-1 users to write unicode strings directly.
Extension modules
-----------------
- cpickle now supports the same keyword arguments as pickle.
Library
-------
- Added new codecs and aliases for ISO_8859-11, ISO_8859-16 and
TIS-620
- Thanks to Edward Loper, doctest has been massively refactored, and
many new features were added. Full docs will appear later. For now
the doctest module comments and new test cases give good coverage.
The refactoring provides many hook points for customizing behavior
(such as how to report errors, and how to compare expected to actual
output). New features include a marker for expected
output containing blank lines, options to produce unified or context
diffs when actual output doesn't match expectations, an option to
normalize whitespace before comparing, and an option to use an
ellipsis to signify "don't care" regions of output.
- Tkinter now supports the wish -sync and -use options.
- The following methods in time support passing of None: ctime(), gmtime(),
and localtime(). If None is provided, the current time is used (the
same as when the argument is omitted).
[SF bug 658254, patch 663482]
- nntplib does now allow to ignore a .netrc file.
- urllib2 now recognizes Basic authentication even if other authentication
schemes are offered.
- Bug #1001053. wave.open() now accepts unicode filenames.
- gzip.GzipFile has a new fileno() method, to retrieve the handle of the
underlying file object (provided it has a fileno() method). This is
needed if you want to use os.fsync() on a GzipFile.
- imaplib has two new methods: deleteacl and myrights.
- nntplib has two new methods: description and descriptions. They
use a more RFC-compliant way of getting a newsgroup description.
- Bug #993394. Fix a possible red herring of KeyError in 'threading' being
raised during interpreter shutdown from a registered function with atexit
when dummy_threading is being used.
- Bug #857297/Patch #916874. Fix an error when extracting a hard link
from a tarfile.
- Patch #846659. Fix an error in tarfile.py when using
GNU longname/longlink creation.
- The obsolete FCNTL.py has been deleted. The builtin fcntl module
has been available (on platforms that support fcntl) since Python
1.5a3, and all FCNTL.py did is export fcntl's names, after generating
a deprecation warning telling you to use fcntl directly.
- Several new unicode codecs are added: big5hkscs, euc_jis_2004,
iso2022_jp_2004, shift_jis_2004.
- Bug #788520. Queue.{get, get_nowait, put, put_nowait} have new
implementations, exploiting Conditions (which didn't exist at the time
Queue was introduced). A minor semantic change is that the Full and
Empty exceptions raised by non-blocking calls now occur only if the
queue truly was full or empty at the instant the queue was checked (of
course the Queue may no longer be full or empty by the time a calling
thread sees those exceptions, though). Before, the exceptions could
also be raised if it was "merely inconvenient" for the implementation
to determine the true state of the Queue (because the Queue was locked
by some other method in progress).
- Bugs #979794 and #980117: difflib.get_grouped_opcodes() now handles the
case of comparing two empty lists. This affected both context_diff() and
unified_diff(),
- Bug #980938: smtplib now prints debug output to sys.stderr.
- Bug #930024: posixpath.realpath() now handles infinite loops in symlinks by
returning the last point in the path that was not part of any loop. Thanks
AM Kuchling.
- Bug #980327: ntpath not handles compressing erroneous slashes between the
drive letter and the rest of the path. Also clearly handles UNC addresses now
as well. Thanks Paul Moore.
- bug #679953: zipfile.py should now work for files over 2 GB. The packed data
for file sizes (compressed and uncompressed) was being stored as signed
instead of unsigned.
- decimal.py now only uses signals in the IBM spec. The other conditions are
no longer part of the public API.
- codecs module now has two new generic APIs: encode() and decode()
which don't restrict the return types (unlike the unicode and
string methods of the same name).
- Non-blocking SSL sockets work again; they were broken in Python 2.3.
SF patch 945642.
- doctest unittest integration improvements:
o Improved the unitest test output for doctest-based unit tests
o Can now pass setUp and tearDown functions when creating
DocTestSuites.
- The threading module has a new class, local, for creating objects
that provide thread-local data.
- Bug #990307: when keep_empty_values is True, cgi.parse_qsl()
no longer returns spurious empty fields.
- Implemented bind_textdomain_codeset() in gettext module.
- Introduced in gettext module the l*gettext() family of functions,
which return translation strings encoded in the preferred encoding,
as informed by locale module's getpreferredencoding().
- optparse module (and tests) upgraded to Optik 1.5a1. Changes:
- Add expansion of default values in help text: the string
"%default" in an option's help string is expanded to str() of
that option's default value, or "none" if no default value.
- Bug #955889: option default values that happen to be strings are
now processed in the same way as values from the command line; this
allows generation of nicer help when using custom types. Can
be disabled with parser.set_process_default_values(False).
- Bug #960515: don't crash when generating help for callback
options that specify 'type', but not 'dest' or 'metavar'.
- Feature #815264: change the default help format for short options
that take an argument from e.g. "-oARG" to "-o ARG"; add
set_short_opt_delimiter() and set_long_opt_delimiter() methods to
HelpFormatter to allow (slight) customization of the formatting.
- Patch #736940: internationalize Optik: all built-in user-
targeted literal strings are passed through gettext.gettext(). (If
you want translations (.po files), they're not included with Python
-- you'll find them in the Optik source distribution from
http://optik.sourceforge.net/ .)
- Bug #878453: respect $COLUMNS environment variable for
wrapping help output.
- Feature #988122: expand "%prog" in the 'description' passed
to OptionParser, just like in the 'usage' and 'version' strings.
(This is *not* done in the 'description' passed to OptionGroup.)
C API
-----
- PyImport_ExecCodeModule() and PyImport_ExecCodeModuleEx(): if an
error occurs while loading the module, these now delete the module's
entry from sys.modules. All ways of loading modules eventually call
one of these, so this is an error-case change in semantics for all
ways of loading modules. In rare cases, a module loader may wish
to keep a module object in sys.modules despite that the module's
code cannot be executed. In such cases, the module loader must
arrange to reinsert the name and module object in sys.modules.
PyImport_ReloadModule() has been changed to reinsert the original
module object into sys.modules if the module reload fails, so that
its visible semantics have not changed.
- A large pile of datetime field-extraction macros is now documented,
thanks to Anthony Tuininga (patch #986010).
Documentation
-------------
- Improved the tutorial on creating types in C.
- point out the importance of reassigning data members before
assigning their values
- correct my misconception about return values from visitprocs. Sigh.
- mention the labor saving Py_VISIT and Py_CLEAR macros.
- Major rewrite of the math module docs, to address common confusions.
Tests
-----
- The test data files for the decimal test suite are now installed on
platforms that use the Makefile.
- SF patch 995225: The test file testtar.tar accidentally contained
CVS keywords (like $Id: NEWS,v 1.1193.2.106 2005/09/20 16:36:07 gvanrossum Exp $), which could cause spurious failures in
test_tarfile.py depending on how the test file was checked out.
What's New in Python 2.4 alpha 1?
=================================
*Release date: 08-JUL-2004*
Core and builtins
-----------------
- weakref.ref is now the type object also known as
weakref.ReferenceType; it can be subclassed like any other new-style
class. There's less per-entry overhead in WeakValueDictionary
objects now (one object instead of three).
- Bug #951851: Python crashed when reading import table of certain
Windows DLLs.
- Bug #215126. The locals argument to eval(), execfile(), and exec now
accept any mapping type.
- marshal now shares interned strings. This change introduces
a new .pyc magic.
- Bug #966623. classes created with type() in an exec(, {}) don't
have a __module__, but code in typeobject assumed it would always
be there.
- Python no longer relies on the LC_NUMERIC locale setting to be
the "C" locale; as a result, it no longer tries to prevent changing
the LC_NUMERIC category.
- Bug #952807: Unpickling pickled instances of subclasses of
datetime.date, datetime.datetime and datetime.time could yield insane
objects. Thanks to Jiwon Seo for a fix.
- Bug #845802: Python crashes when __init__.py is a directory.
- Unicode objects received two new methods: iswide() and width().
These query East Asian width information, as specified in Unicode
TR11.
- Improved the tuple hashing algorithm to give fewer collisions in
common cases. Fixes bug #942952.
- Implemented generator expressions (PEP 289). Coded by Jiwon Seo.
- Enabled the profiling of C extension functions (and builtins) - check
new documentation and modified profile and bdb modules for more details
- Set file.name to the object passed to open (instead of a new string)
- Moved tracebackobject into traceback.h and renamed to PyTracebackObject
- Optimized the byte coding for multiple assignments like "a,b=b,a" and
"a,b,c=1,2,3". Improves their speed by 25% to 30%.
- Limit the nested depth of a tuple for the second argument to isinstance()
and issubclass() to the recursion limit of the interpreter.
Fixes bug #858016 .
- Optimized dict iterators, creating separate types for each
and having them reveal their length. Also optimized the
methods: keys(), values(), and items().
- Implemented a newcode opcode, LIST_APPEND, that simplifies
the generated bytecode for list comprehensions and further
improves their performance (about 35%).
- Implemented rich comparisons for floats, which seems to make
comparisons involving NaNs somewhat less surprising when the
underlying C compiler actually implements C99 semantics.
- Optimized list.extend() to save memory and no longer create
intermediate sequences. Also, extend() now pre-allocates the
needed memory whenever the length of the iterable is known in
advance -- this halves the time to extend the list.
- Optimized list resize operations to make fewer calls to the system
realloc(). Significantly speeds up list appends, list pops,
list comprehensions, and the list constructor (when the input iterable
length is not known).
- Changed the internal list over-allocation scheme. For larger lists,
overallocation ranged between 3% and 25%. Now, it is a constant 12%.
For smaller lists (n<8), overallocation was upto eight elements. Now,
the overallocation is no more than three elements -- this improves space
utilization for applications that have large numbers of small lists.
- Most list bodies now get re-used rather than freed. Speeds up list
instantiation and deletion by saving calls to malloc() and free().
- The dict.update() method now accepts all the same argument forms
as the dict() constructor. This now includes item lists and/or
keyword arguments.
- Support for arbitrary objects supporting the read-only buffer
interface as the co_code field of code objects (something that was
only possible to create from C code) has been removed.
- Made omitted callback and None equivalent for weakref.ref() and
weakref.proxy(); the None case wasn't handled correctly in all
cases.
- Fixed problem where PyWeakref_NewRef() and PyWeakref_NewProxy()
assumed that initial existing entries in an object's weakref list
would not be removed while allocating a new weakref object. Since
GC could be invoked at that time, however, that assumption was
invalid. In a truly obscure case of GC being triggered during
creation for a new weakref object for an referent which already
has a weakref without a callback which is only referenced from
cyclic trash, a memory error can occur. This consistently created a
segfault in a debug build, but provided less predictable behavior in
a release build.
- input() builtin function now respects compiler flags such as
__future__ statements. SF patch 876178.
- Removed PendingDeprecationWarning from apply(). apply() remains
deprecated, but the nuisance warning will not be issued.
- At Python shutdown time (Py_Finalize()), 2.3 called cyclic garbage
collection twice, both before and after tearing down modules. The
call after tearing down modules has been disabled, because too much
of Python has been torn down then for __del__ methods and weakref
callbacks to execute sanely. The most common symptom was a sequence
of uninformative messages on stderr when Python shut down, produced
by threads trying to raise exceptions, but unable to report the nature
of their problems because too much of the sys module had already been
destroyed.
- Removed FutureWarnings related to hex/oct literals and conversions
and left shifts. (Thanks to Kalle Svensson for SF patch 849227.)
This addresses most of the remaining semantic changes promised by
PEP 237, except for repr() of a long, which still shows the trailing
'L'. The PEP appears to promise warnings for operations that
changed semantics compared to Python 2.3, but this is not
implemented; we've suffered through enough warnings related to
hex/oct literals and I think it's best to be silent now.
- For str and unicode objects, the ljust(), center(), and rjust()
methods now accept an optional argument specifying a fill
character other than a space.
- When method objects have an attribute that can be satisfied either
by the function object or by the method object, the function
object's attribute usually wins. Christian Tismer pointed out that
that this is really a mistake, because this only happens for special
methods (like __reduce__) where the method object's version is
really more appropriate than the function's attribute. So from now
on, all method attributes will have precedence over function
attributes with the same name.
- Critical bugfix, for SF bug 839548: if a weakref with a callback,
its callback, and its weakly referenced object, all became part of
cyclic garbage during a single run of garbage collection, the order
in which they were torn down was unpredictable. It was possible for
the callback to see partially-torn-down objects, leading to immediate
segfaults, or, if the callback resurrected garbage objects, to
resurrect insane objects that caused segfaults (or other surprises)
later. In one sense this wasn't surprising, because Python's cyclic gc
had no knowledge of Python's weakref objects. It does now. When
weakrefs with callbacks become part of cyclic garbage now, those
weakrefs are cleared first. The callbacks don't trigger then,
preventing the problems. If you need callbacks to trigger, then just
as when cyclic gc is not involved, you need to write your code so
that weakref objects outlive the objects they weakly reference.
- Critical bugfix, for SF bug 840829: if cyclic garbage collection
happened to occur during a weakref callback for a new-style class
instance, subtle memory corruption was the result (in a release build;
in a debug build, a segfault occurred reliably very soon after).
This has been repaired.
- Compiler flags set in PYTHONSTARTUP are now active in __main__.
- Added two builtin types, set() and frozenset().
- Added a reversed() builtin function that returns a reverse iterator
over a sequence.
- Added a sorted() builtin function that returns a new sorted list
from any iterable.
- CObjects are now mutable (on the C level) through PyCObject_SetVoidPtr.
- list.sort() now supports three keyword arguments: cmp, key, and reverse.
The key argument can be a function of one argument that extracts a
comparison key from the original record: mylist.sort(key=str.lower).
The reverse argument is a boolean value and if True will change the
sort order as if the comparison arguments were reversed. In addition,
the documentation has been amended to provide a guarantee that all sorts
starting with Py2.3 are guaranteed to be stable (the relative order of
records with equal keys is unchanged).
- Added test whether wchar_t is signed or not. A signed wchar_t is not
usable as internal unicode type base for Py_UNICODE since the
unicode implementation assumes an unsigned type.
- Fixed a bug in the cache of length-one Unicode strings that could
lead to a seg fault. The specific problem occurred when an earlier,
non-fatal error left an uninitialized Unicode object in the
freelist.
- The % formatting operator now supports '%F' which is equivalent to
'%f'. This has always been documented but never implemented.
- complex(obj) could leak a little memory if obj wasn't a string or
number.
- zip() with no arguments now returns an empty list instead of raising
a TypeError exception.
- obj.__contains__() now returns True/False instead of 1/0. SF patch
820195.
- Python no longer tries to be smart about recursive comparisons.
When comparing containers with cyclic references to themselves it
will now just hit the recursion limit. See SF patch 825639.
- str and unicode builtin types now have an rsplit() method that is
same as split() except that it scans the string from the end
working towards the beginning. See SF feature request 801847.
- Fixed a bug in object.__reduce_ex__ when using protocol 2. Failure
to clear the error when attempts to get the __getstate__ attribute
fail caused intermittent errors and odd behavior.
- buffer objects based on other objects no longer cache a pointer to
the data and the data length. Instead, the appropriate tp_as_buffer
method is called as necessary.
- fixed: if a file is opened with an explicit buffer size >= 1, repeated
close() calls would attempt to free() the buffer already free()ed on
the first call.
Extension modules
-----------------
- Added socket.getservbyport(), and make the second argument in
getservbyname() and getservbyport() optional.
- time module code that deals with input POSIX timestamps will now raise
ValueError if more than a second is lost in precision when the
timestamp is cast to the platform C time_t type. There's no chance
that the platform will do anything sensible with the result in such
cases. This includes ctime(), localtime() and gmtime(). Assorted
fromtimestamp() and utcfromtimestamp() methods in the datetime module
were also protected. Closes bugs #919012 and 975996.
- fcntl.ioctl now warns if the mutate flag is not specified.
- nt now properly allows to refer to UNC roots, e.g. in nt.stat().
- the weakref module now supports additional objects: array.array,
sre.pattern_objects, file objects, and sockets.
- operator.isMappingType() and operator.isSequenceType() now give
fewer false positives.
- socket.sslerror is now a subclass of socket.error . Also added
socket.error to the socket module's C API.
- Bug #920575: A problem where the _locale module segfaults on
nl_langinfo(ERA) caused by GNU libc's illegal NULL return is fixed.
- array objects now support the copy module. Also, their resizing
scheme has been updated to match that used for list objects. This improves
the performance (speed and memory usage) of append() operations.
Also, array.array() and array.extend() now accept any iterable argument
for repeated appends without needing to create another temporary array.
- cStringIO.writelines() now accepts any iterable argument and writes
the lines one at a time rather than joining them and writing once.
Made a parallel change to StringIO.writelines(). Saves memory and
makes suitable for use with generator expressions.
- time.strftime() now checks that the values in its time tuple argument
are within the proper boundaries to prevent possible crashes from the
platform's C library implementation of strftime(). Can possibly
break code that uses values outside the range that didn't cause
problems previously (such as sitting day of year to 0). Fixes bug
#897625.
- The socket module now supports Bluetooth sockets, if the
system has
- Added a collections module containing a new datatype, deque(),
offering high-performance, thread-safe, memory friendly appends
and pops on either side of the deque.
- Several modules now take advantage of collections.deque() for
improved performance: Queue, mutex, shlex, threading, and pydoc.
- The operator module has two new functions, attrgetter() and
itemgetter() which are useful for creating fast data extractor
functions for map(), list.sort(), itertools.groupby(), and
other functions that expect a function argument.
- socket.SHUT_{RD,WR,RDWR} was added.
- os.getsid was added.
- The pwd module incorrectly advertised its struct type as
struct_pwent; this has been renamed to struct_passwd. (The old name
is still supported for backwards compatibility.)
- The xml.parsers.expat module now provides Expat 1.95.7.
- socket.IPPROTO_IPV6 was added.
- readline.clear_history was added.
- select.select() now accepts sequences for its first three arguments.
- cStringIO now supports the f.closed attribute.
- The signal module now exposes SIGRTMIN and SIGRTMAX (if available).
- curses module now supports use_default_colors(). [patch #739124]
- Bug #811028: ncurses.h breakage on FreeBSD/MacOS X
- Bug #814613: INET_ADDRSTRLEN fix needed for all compilers on SGI
- Implemented non-recursive SRE matching scheme (#757624).
- Implemented (?(id/name)yes|no) support in SRE (#572936).
- random.seed() with no arguments or None uses time.time() as a default
seed. Modified to match Py2.2 behavior and use fractional seconds so
that successive runs are more likely to produce different sequences.
- random.Random has a new method, getrandbits(k), which returns an int
with k random bits. This method is now an optional part of the API
for user defined generators. Any generator that defines genrandbits()
can now use randrange() for ranges with a length >= 2**53. Formerly,
randrange would return only even numbers for ranges that large (see
SF bug #812202). Generators that do not define genrandbits() now
issue a warning when randrange() is called with a range that large.
- itertools has a new function, groupby() for aggregating iterables
into groups sharing the same key (as determined by a key function).
It offers some of functionality of SQL's groupby keyword and of
the Unix uniq filter.
- itertools now has a new tee() function which produces two independent
iterators from a single iterable.
- itertools.izip() with no arguments now returns an empty iterator instead
of raising a TypeError exception.
- Fixed #853061: allow BZ2Compressor.compress() to receive an empty string
as parameter.
Library
-------
- Bug #981530: Fix UnboundLocalError in shutil.rmtree(). This affects
the documented behavior: the function passed to the onerror()
handler can now also be os.listdir.
- Bug #754449: threading.Thread objects no longer mask exceptions raised during
interpreter shutdown with another exception from attempting to handle the
original exception.
- Added decimal.py per PEP 327.
- Bug #981299: rsync is now a recognized protocol in urlparse that uses a
"netloc" portion of a URL.
- Bug #919012: shutil.move() will not try to move a directory into itself.
Thanks Johannes Gijsbers.
- Bug #934282: pydoc.stripid() is now case-insensitive. Thanks Robin Becker.
- Bug #823209: cmath.log() now takes an optional base argument so that its
API matches math.log().
- Bug #957381: distutils bdist_rpm no longer fails on recent RPM versions
that generate a -debuginfo.rpm
- os.path.devnull has been added for all supported platforms.
- Fixed #877165: distutils now picks the right C++ compiler command
on cygwin and mingw32.
- urllib.urlopen().readline() now handles HTTP/0.9 correctly.
- refactored site.py into functions. Also wrote regression tests for the
module.
- The distutils install command now supports the --home option and
installation scheme for all platforms.
- asyncore.loop now has a repeat count parameter that defaults to
looping forever.
- The distutils sdist command now ignores all .svn directories, in
addition to CVS and RCS directories. .svn directories hold
administrative files for the Subversion source control system.
- Added a new module: cookielib. Automatic cookie handling for HTTP
clients. Also, support for cookielib has been added to urllib2, so
urllib2.urlopen() can transparently handle cookies.
- stringprep.py now uses built-in set() instead of sets.Set().
- Bug #876278: Unbounded recursion in modulefinder
- Bug #780300: Swap public and system ID in LexicalHandler.startDTD.
Applications relying on the wrong order need to be corrected.
- Bug #926075: Fixed a bug that returns a wrong pattern object
for a string or unicode object in sre.compile() when a different
type pattern with the same value exists.
- Added countcallers arg to trace.Trace class (--trackcalls command line arg
when run from the command prompt).
- Fixed a caching bug in platform.platform() where the argument of 'terse' was
not taken into consideration when caching value.
- Added two new command-line arguments for profile (output file and
default sort).
- Added global runctx function to profile module
- Add hlist missing entryconfigure and entrycget methods.
- The ptcp154 codec was added for Kazakh character set support.
- Support non-anonymous ftp URLs in urllib2.
- The encodings package will now apply codec name aliases
first before starting to try the import of the codec module.
This simplifies overriding built-in codecs with external
packages, e.g. the included CJK codecs with the JapaneseCodecs
package, by adjusting the aliases dictionary in encodings.aliases
accordingly.
- base64 now supports RFC 3548 Base16, Base32, and Base64 encoding and
decoding standards.
- urllib2 now supports processors. A processor is a handler that
implements an xxx_request or xxx_response method. These methods are
called for all requests.
- distutils compilers now compile source files in the same order as
they are passed to the compiler.
- pprint.pprint() and pprint.pformat() now have additional parameters
indent, width and depth.
- Patch #750542: pprint now will pretty print subclasses of list, tuple
and dict too, as long as they don't overwrite __repr__().
- Bug #848614: distutils' msvccompiler fails to find the MSVC6
compiler because of incomplete registry entries.
- httplib.HTTP.putrequest now offers to omit the implicit Accept-Encoding.
- Patch #841977: modulefinder didn't find extension modules in packages
- imaplib.IMAP4.thread was added.
- Plugged a minor hole in tempfile.mktemp() due to the use of
os.path.exists(), switched to using os.lstat() directly if possible.
- bisect.py and heapq.py now have underlying C implementations
for better performance.
- heapq.py has two new functions, nsmallest() and nlargest().
- traceback.format_exc has been added (similar to print_exc but it returns
a string).
- xmlrpclib.MultiCall has been added.
- poplib.POP3_SSL has been added.
- tmpfile.mkstemp now returns an absolute path even if dir is relative.
- urlparse is RFC 2396 compliant.
- The fieldnames argument to the csv module's DictReader constructor is now
optional. If omitted, the first row of the file will be used as the
list of fieldnames.
- encodings.bz2_codec was added for access to bz2 compression
using "a long string".encode('bz2')
- Various improvements to unittest.py, realigned with PyUnit CVS.
- dircache now passes exceptions to the caller, instead of returning
empty lists.
- The bsddb module and dbhash module now support the iterator and
mapping protocols which make them more substitutable for dictionaries
and shelves.
- The csv module's DictReader and DictWriter classes now accept keyword
arguments. This was an omission in the initial implementation.
- The email package handles some RFC 2231 parameters with missing
CHARSET fields better. It also includes a patch to parameter
parsing when semicolons appear inside quotes.
- sets.py now runs under Py2.2. In addition, the argument restrictions
for most set methods (but not the operators) have been relaxed to
allow any iterable.
- _strptime.py now has a behind-the-scenes caching mechanism for the most
recent TimeRE instance used along with the last five unique directive
patterns. The overall module was also made more thread-safe.
- random.cunifvariate() and random.stdgamma() were deprecated in Py2.3
and removed in Py2.4.
- Bug #823328: urllib2.py's HTTP Digest Auth support works again.
- Patch #873597: CJK codecs are imported into rank of default codecs.
Tools/Demos
-----------
- A hotshotmain script was added to the Tools/scripts directory that
makes it easy to run a script under control of the hotshot profiler.
- The db2pickle and pickle2db scripts can now dump/load gdbm files.
- The file order on the command line of the pickle2db script was reversed.
It is now [ picklefile ] dbfile. This provides better symmetry with
db2pickle. The file arguments to both scripts are now source followed by
destination in situations where both files are given.
- The pydoc script will display a link to the module documentation for
modules determined to be part of the core distribution. The documentation
base directory defaults to http://www.python.org/doc/current/lib/ but can
be changed by setting the PYTHONDOCS environment variable.
- texcheck.py now detects double word errors.
- md5sum.py mistakenly opened input files in text mode by default, a
silent and dangerous change from previous releases. It once again
opens input files in binary mode by default. The -t and -b flags
remain for compatibility with the 2.3 release, but -b is the default
now.
- py-electric-colon now works when pending-delete/delete-selection mode is
in effect
- py-help-at-point is no longer bound to the F1 key - it's still bound to
C-c C-h
- Pynche was fixed to not crash when there is no ~/.pynche file and no
-d option was given.
Build
-----
- Bug #978645: Modules/getpath.c now builds properly in --disable-framework
build under OS X.
- Profiling using gprof is now available if Python is configured with
--enable-profiling.
- Profiling the VM using the Pentium TSC is now possible if Python
is configured --with-tsc.
- In order to find libraries, setup.py now also looks in /lib64, for use
on AMD64.
- Bug #934635: Fixed a bug where the configure script couldn't detect
getaddrinfo() properly if the KAME stack had SCTP support.
- Support for missing ANSI C header files (limits.h, stddef.h, etc) was
removed.
- Systems requiring the D4, D6 or D7 variants of pthreads are no longer
supported (see PEP 11).
- Universal newline support can no longer be disabled (see PEP 11).
- Support for DGUX, SunOS 4, IRIX 4 and Minix was removed (see PEP 11).
- Support for systems requiring --with-dl-dld or --with-sgi-dl was removed
(see PEP 11).
- Tests for sizeof(char) were removed since ANSI C mandates that
sizeof(char) must be 1.
C API
-----
- Thanks to Anthony Tuininga, the datetime module now supplies a C API
containing type-check macros and constructors. See new docs in the
Python/C API Reference Manual for details.
- Private function _PyTime_DoubleToTimet added, to convert a Python
timestamp (C double) to platform time_t with some out-of-bounds
checking. Declared in new header file timefuncs.h. It would be
good to expose some other internal timemodule.c functions there.
- New public functions PyEval_EvaluateFrame and PyGen_New to expose
generator objects.
- New public functions Py_IncRef() and Py_DecRef(), exposing the
functionality of the Py_XINCREF() and Py_XDECREF macros. Useful for
runtime dynamic embedding of Python. See patch #938302, by Bob
Ippolito.
- Added a new macro, PySequence_Fast_ITEMS, which retrieves a fast sequence's
underlying array of PyObject pointers. Useful for high speed looping.
- Created a new method flag, METH_COEXIST, which causes a method to be loaded
even if already defined by a slot wrapper. This allows a __contains__
method, for example, to co-exist with a defined sq_contains slot. This
is helpful because the PyCFunction can take advantage of optimized calls
whenever METH_O or METH_NOARGS flags are defined.
- Added a new function, PyDict_Contains(d, k) which is like
PySequence_Contains() but is specific to dictionaries and executes
about 10% faster.
- Added three new macros: Py_RETURN_NONE, Py_RETURN_TRUE, and Py_RETURN_FALSE.
Each return the singleton they mention after Py_INCREF()ing them.
- Added a new function, PyTuple_Pack(n, ...) for constructing tuples from a
variable length argument list of Python objects without having to invoke
the more complex machinery of Py_BuildValue(). PyTuple_Pack(3, a, b, c)
is equivalent to Py_BuildValue("(OOO)", a, b, c).
Windows
-------
- The _winreg module could segfault when reading very large registry
values, due to unchecked alloca() calls (SF bug 851056). The fix is
uses either PyMem_Malloc(n) or PyString_FromStringAndSize(NULL, n),
as appropriate, followed by a size check.
- file.truncate() could misbehave if the file was open for update
(modes r+, rb+, w+, wb+), and the most recent file operation before
the truncate() call was an input operation. SF bug 801631.
**(For information about older versions, consult the HISTORY file.)**