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Diffstat (limited to 'Misc')
| -rw-r--r-- | Misc/NEWS | 6213 |
1 files changed, 13 insertions, 6200 deletions
@@ -4,6245 +4,58 @@ Python News (editors: check NEWS.help for information about editing NEWS using ReST.) -What's New in Python 2.5 alpha 1? -================================= +What's New in Python 3000? +========================== -*Release date: XX-XXX-2006* +*Release date: XX-XXX-200X* -Core and builtins ------------------ - -- Patch #1434038: property() now uses the getter's docstring if there is - no "doc" argument given. This makes it possible to legitimately use - property() as a decorator to produce a read-only property. - -- PEP 357, patch 1436368: add an __index__ method to int/long and a matching - nb_index slot to the PyNumberMethods struct. The slot is consulted instead - of requiring an int or long in slicing and a few other contexts, enabling - other objects (e.g. Numeric Python's integers) to be used as slice indices. - -- Fixed various bugs reported by Coverity's Prevent tool. - -- PEP 352, patch #1104669: Make exceptions new-style objects. Introduced the - new exception base class, BaseException, which has a new message attribute. - KeyboardInterrupt and SystemExit to directly inherit from BaseException now. - Raising a string exception now raises a DeprecationWarning. - -- Patch #1438387, PEP 328: relative and absolute imports. Imports can now be - explicitly relative, using 'from .module import name' to mean 'from the same - package as this module is in. Imports without dots still default to the - old relative-then-absolute, unless 'from __future__ import - absolute_import' is used. - -- Properly check if 'warnings' raises an exception (usually when a filter set - to "error" is triggered) when raising a warning for raising string - exceptions. - -- CO_GENERATOR_ALLOWED is no longer defined, this behavior is the default. - The name was removed from Include/code.h. - -- PEP 308: conditional expressions were added (x if cond else y). - -- Patch 1433928: - - The copy module now "copies" function objects (as atomic objects). - - dict.__getitem__ now looks for a __missing__ hook before raising - KeyError. - -- PEP 343: with statement implemented. Needs ``from __future__ import - with_statement``. Use of 'with' as a variable will generate a warning. - Use of 'as' as a variable will also generate a warning (unless it's - part of an import statement). - The following objects have __context__ methods: - - The built-in file type. - - The thread.LockType type. - - The following types defined by the threading module: - Lock, RLock, Condition, Semaphore, BoundedSemaphore. - - The decimal.Context class. - -- Fix the encodings package codec search function to only search - inside its own package. Fixes problem reported in patch #1433198. - - Note: Codec packages should implement and register their own - codec search function. PEP 100 has the details. - -- PEP 353: Using ssize_t as the index type. - -- Patch #1400181, fix unicode string formatting to not use the locale. - This is how string objects work. u'%f' could use , instead of . - for the decimal point. Now both strings and unicode always use periods. - -- Bug #1244610, #1392915, fix build problem on OpenBSD 3.7 and 3.8. - configure would break checking curses.h. - -- Bug #959576: The pwd module is now builtin. This allows Python to be - built on UNIX platforms without $HOME set. - -- Bug #1072182, fix some potential problems if characters are signed. - -- Bug #889500, fix line number on SyntaxWarning for global declarations. - -- Bug #1378022, UTF-8 files with a leading BOM crashed the interpreter. - -- Support for converting hex strings to floats no longer works. - This was not portable. float('0x3') now raises a ValueError. - -- Patch #1382163: Expose Subversion revision number to Python. New C API - function Py_GetBuildNumber(). New attribute sys.subversion. Build number - is now displayed in interactive prompt banner. - -- Implementation of PEP 341 - Unification of try/except and try/finally. - "except" clauses can now be written together with a "finally" clause in - one try statement instead of two nested ones. Patch #1355913. - -- Bug #1379994: Builtin unicode_escape and raw_unicode_escape codec - now encodes backslash correctly. - -- Patch #1350409: Work around signal handling bug in Visual Studio 2005. - -- Bug #1281408: Py_BuildValue now works correct even with unsigned longs - and long longs. - -- SF Bug #1350188, "setdlopenflags" leads to crash upon "import" - It was possible dlerror() returns a NULL pointer, use a default error - message in this case. - -- Replaced most Unicode charmap codecs with new ones using the - new Unicode translate string feature in the builtin charmap - codec; the codecs were created from the mapping tables available - at ftp.unicode.org and contain a few updates (e.g. the Mac OS - encodings now include a mapping for the Apple logo) - -- Added a few more codecs for Mac OS encodings - -- Speed up some Unicode operations. - -- A new AST parser implementation was completed. The abstract - syntax tree is available for read-only (non-compile) access - to Python code; an _ast module was added. - -- SF bug #1167751: fix incorrect code being for generator expressions. - The following code now raises a SyntaxError: foo(a = i for i in range(10)) - -- SF Bug #976608: fix SystemError when mtime of an imported file is -1. - -- SF Bug #887946: fix segfault when redirecting stdin from a directory. - Provide a warning when a directory is passed on the command line. - -- Fix segfault with invalid coding. - -- SF bug #772896: unknown encoding results in MemoryError. - -- All iterators now have a Boolean value of true. Formerly, some iterators - supported a __len__() method which evaluated to False when the iterator - was empty. - -- On 64-bit platforms, when __len__() returns a value that cannot be - represented as a C int, raise OverflowError. - -- test__locale is skipped on OS X < 10.4 (only partial locale support is - present). - -- 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. - -- The implementation of set() and frozenset() was revised to use its - own internal data structure. Memory consumption is reduced by 1/3 - and there are modest speed-ups as well. The API is unchanged. - -- SF bug #1238681: freed pointer is used in longobject.c:long_pow(). - -- SF bug #1229429: PyObject_CallMethod failed to decrement some - reference counts in some error exit cases. - -- 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. - -- SF bug #1232517: An overflow error was not detected properly when - attempting to convert a large float to an int in os.utime(). - -- SF bug #1224347: hex longs now print with lowercase letters just - like their int counterparts. - -- SF bug #1163563: the original fix for bug #1010677 ("thread Module - Breaks PyGILState_Ensure()") broke badly in the case of multiple - interpreter states; back out that fix and do a better job (see - http://mail.python.org/pipermail/python-dev/2005-June/054258.html - for a longer write-up of the problem). - -- SF patch #1180995: marshal now uses a binary format by default when - serializing floats. - -- SF patch #1181301: on platforms that appear to use IEEE 754 floats, - the routines that promise to produce IEEE 754 binary representations - of floats now simply copy bytes around. - -- bug #967182: disallow opening files with 'wU' or 'aU' as specified by PEP - 278. - -- patch #1109424: int, long, float, complex, and unicode now check for the - proper magic slot for type conversions when subclassed. Previously the - magic slot was ignored during conversion. Semantics now match the way - subclasses of str always behaved. int/long/float, conversion of an instance - to the base class has been moved to the proper nb_* magic slot and out of - PyNumber_*(). - Thanks Walter Dörwald. - -- Descriptors defined in C with a PyGetSetDef structure, where the setter is - NULL, now raise an AttributeError when attempting to set or delete the - attribute. Previously a TypeError was raised, but this was inconsistent - with the equivalent pure-Python implementation. - -- 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. - -- Move exception finalisation later in the shutdown process - this - fixes the crash seen in bug #1165761 - -- Added two new builtins, any() and all(). - -- Defining a class with empty parentheses is now allowed - (e.g., ``class C(): pass`` is no longer a syntax error). - Patch #1176012 added support to the 'parser' module and 'compiler' package - (thanks to logistix for that added support). - -- Patch #1115086: Support PY_LONGLONG in structmember. - -- Bug #1155938: new style classes did not check that __init__() was - returning None. - -- Patch #802188: Report characters after line continuation character - ('\') with a specific error message. - -- 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. - -- min() and max() now support key= arguments with the same meaning as in - list.sort(). - -- The peephole optimizer now performs simple constant folding in expressions: - (2+3) --> (5). - -- set and frozenset objects can now be marshalled. SF #1098985. - -- Bug #1077106: Poor argument checking could cause memory corruption - in calls to os.read(). - -- The parser did not complain about future statements in illegal - positions. It once again reports a syntax error if a future - statement occurs after anything other than a doc string. - -- Change the %s format specifier for str objects so that it returns a - unicode instance if the argument is not an instance of basestring and - calling __str__ on the argument returns a unicode instance. - -- Patch #1413181: changed ``PyThreadState_Delete()`` to forget about the - current thread state when the auto-GIL-state machinery knows about - it (since the thread state is being deleted, continuing to remember it - can't help, but can hurt if another thread happens to get created with - the same thread id). - -Extension Modules ------------------ - -- Bug #1448490: Fixed a bug that ISO-2022 codecs could not handle - SS2 (single-shift 2) escape sequences correctly. - -- The unicodedata module was updated to the 4.1 version of the Unicode - database. The 3.2 version is still available as unicodedata.db_3_2_0 - for applications that require this specific version (such as IDNA). - -- The timing module is no longer built by default. It was deprecated - in PEP 4 in Python 2.0 or earlier. - -- Patch 1433928: Added a new type, defaultdict, to the collections module. - This uses the new __missing__ hook behavior added to dict (see above). - -- Bug #854823: socketmodule now builds on Sun platforms even when - INET_ADDRSTRLEN is not defined. - -- Patch #1393157: os.startfile() now has an optional argument to specify - a "command verb" to invoke on the file. - -- Bug #876637, prevent stack corruption when socket descriptor - is larger than FD_SETSIZE. - -- Patch #1407135, bug #1424041: harmonize mmap behavior of anonymous memory. - mmap.mmap(-1, size) now returns anonymous memory in both Unix and Windows. - mmap.mmap(0, size) should not be used on Windows for anonymous memory. - -- Patch #1422385: The nis module now supports access to domains other - than the system default domain. - -- Use Win32 API to implement os.stat/fstat. As a result, subsecond timestamps - are reported, the limit on path name lengths is removed, and stat reports - WindowsError now (instead of OSError). - -- Add bsddb.db.DBEnv.set_tx_timestamp allowing time based database recovery. - -- Bug #1413192, fix seg fault in bsddb if a transaction was deleted - before the env. - -- Patch #1103116: Basic AF_NETLINK support. - -- Bug #1402308, (possible) segfault when using mmap.mmap(-1, ...) - -- Bug #1400822, _curses over{lay,write} doesn't work when passing 6 ints. - Also fix ungetmouse() which did not accept arguments properly. - The code now conforms to the documented signature. - -- Bug #1400115, Fix segfault when calling curses.panel.userptr() - without prior setting of the userptr. - -- Fix 64-bit problems in bsddb. - -- Patch #1365916: fix some unsafe 64-bit mmap methods. - -- Bug #1290333: Added a workaround for cjkcodecs' _codecs_cn build - problem on AIX. - -- Bug #869197: os.setgroups rejects long integer arguments - -- Bug #1346533, select.poll() doesn't raise an error if timeout > sys.maxint - -- Bug #1344508, Fix UNIX mmap leaking file descriptors - -- Patch #1338314, Bug #1336623: fix tarfile so it can extract - REGTYPE directories from tarfiles written by old programs. - -- Patch #1407992, fixes broken bsddb module db associate when using - BerkeleyDB 3.3, 4.0 or 4.1. - -- Get bsddb module to build with BerkeleyDB version 4.4 - -- Get bsddb module to build with BerkeleyDB version 3.2 - -- Patch #1309009, Fix segfault in pyexpat when the XML document is in latin_1, - but Python incorrectly assumes it is in UTF-8 format - -- Fix parse errors in the readline module when compiling without threads. - -- Patch #1288833: Removed thread lock from socket.getaddrinfo on - FreeBSD 5.3 and later versions which got thread-safe getaddrinfo(3). - -- 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 - -- 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. - -- Patch #1180695: Add nanosecond stat resolution, and st_gen, - st_birthtime for FreeBSD. - -- Patch #1231069: The fcntl.ioctl function now uses the 'I' code for - the request code argument, which results in more C-like behaviour - for large or negative values. - -- Bug #1234979: For the argument of thread.Lock.acquire, the Windows - implementation treated all integer values except 1 as false. - -- Bug #1194181: bz2.BZ2File didn't handle mode 'U' correctly. - -- Patch #1212117: os.stat().st_flags is now accessible as a attribute - if available on the platform. - -- Patch #1103951: Expose O_SHLOCK and O_EXLOCK in the posix module if - available on the platform. - -- Bug #1166660: The readline module could segfault if hook functions - were set in a different thread than that which called readline. - -- collections.deque objects now support a remove() method. - -- operator.itemgetter() and operator.attrgetter() now support retrieving - multiple fields. This provides direct support for sorting on multiple - keys (primary, secondary, etc). - -- os.access now supports Unicode path names on non-Win32 systems. - -- Patches #925152, #1118602: Avoid reading after the end of the buffer - in pyexpat.GetInputContext. - -- Patches #749830, #1144555: allow UNIX mmap size to default to current - file size. - -- Added functional.partial(). See PEP309. - -- Patch #1093585: raise a ValueError for negative history items in readline. - {remove_history,replace_history} - -- The spwd module has been added, allowing access to the shadow password - database. - -- stat_float_times is now True. - -- array.array objects are now picklable. - -- the cPickle module no longer accepts the deprecated None option in the - args tuple returned by __reduce__(). - -- itertools.islice() now accepts None for the start and step arguments. - This allows islice() to work more readily with slices: - islice(s.start, s.stop, s.step) - -- datetime.datetime() now has a strptime class method which can be used to - create datetime object using a string and format. - -Library -------- - -- A regrtest option -w was added to re-run failed tests in verbose mode. - -- Patch #1446372: quit and exit can now be called from the interactive - interpreter to exit. - -- The function get_count() has been added to the gc module, and gc.collect() - grew an optional 'generation' argument. - -- A library msilib to generate Windows Installer files, and a distutils - command bdist_msi have been added. - -- PEP 343: new module contextlib.py defines decorator @contextmanager - and helpful context managers nested() and closing(). - -- The compiler package now supports future imports after the module docstring. - -- Bug #1413790: zipfile now sanitizes absolute archive names that are - not allowed by the specs. - -- Patch #1215184: FileInput now can be given an opening hook which can - be used to control how files are opened. - -- Patch #1212287: fileinput.input() now has a mode parameter for - specifying the file mode input files should be opened with. - -- Patch #1215184: fileinput now has a fileno() function for getting the - current file number. - -- Patch #1349274: gettext.install() now optionally installs additional - translation functions other than _() in the builtin namespace. - -- Patch #1337756: fileinput now accepts Unicode filenames. - -- Patch #1373643: The chunk module can now read chunks larger than - two gigabytes. - -- Patch #1417555: SimpleHTTPServer now returns Last-Modified headers. - -- Bug #1430298: It is now possible to send a mail with an empty - return address using smtplib. - -- Bug #1432260: The names of lambda functions are now properly displayed - in pydoc. - -- Patch #1412872: zipfile now sets the creator system to 3 (Unix) - unless the system is Win32. - -- Patch #1349118: urllib now supports user:pass@ style proxy - specifications, raises IOErrors when proxies for unsupported protocols - are defined, and uses the https proxy on https redirections. - -- Bug #902075: urllib2 now supports 'host:port' style proxy specifications. - -- Bug #1407902: Add support for sftp:// URIs to urlparse. - -- Bug #1371247: Update Windows locale identifiers in locale.py. - -- Bug #1394565: SimpleHTTPServer now doesn't choke on query parameters - any more. - -- Bug #1403410: The warnings module now doesn't get confused - when it can't find out the module name it generates a warning for. - -- Patch #1177307: Added a new codec utf_8_sig for UTF-8 with a BOM signature. - -- Patch #1157027: cookielib mishandles RFC 2109 cookies in Netscape mode - -- Patch #1117398: cookielib.LWPCookieJar and .MozillaCookieJar now raise - LoadError as documented, instead of IOError. For compatibility, - LoadError subclasses IOError. - -- Added the hashlib module. It provides secure hash functions for MD5 and - SHA1, 224, 256, 384, and 512. Note that recent developments make the - historic MD5 and SHA1 unsuitable for cryptographic-strength applications. - In <http://mail.python.org/pipermail/python-dev/2005-December/058850.html> - Ronald L. Rivest offered this advice for Python: - - "The consensus of researchers in this area (at least as - expressed at the NIST Hash Function Workshop 10/31/05), - is that SHA-256 is a good choice for the time being, but - that research should continue, and other alternatives may - arise from this research. The larger SHA's also seem OK." - -- Added a subset of Fredrik Lundh's ElementTree package. Available - modules are xml.etree.ElementTree, xml.etree.ElementPath, and - xml.etree.ElementInclude, from ElementTree 1.2.6. - -- Patch #1162825: Support non-ASCII characters in IDLE window titles. - -- Bug #1365984: urllib now opens "data:" URLs again. - -- Patch #1314396: prevent deadlock for threading.Thread.join() when an exception - is raised within the method itself on a previous call (e.g., passing in an - illegal argument) - -- Bug #1340337: change time.strptime() to always return ValueError when there - is an error in the format string. - -- Patch #754022: Greatly enhanced webbrowser.py (by Oleg Broytmann). - -- Bug #729103: pydoc.py: Fix docother() method to accept additional - "parent" argument. - -- Patch #1300515: xdrlib.py: Fix pack_fstring() to really use null bytes - for padding. - -- Bug #1296004: httplib.py: Limit maximal amount of data read from the - socket to avoid a MemoryError on Windows. - -- 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: Fix clearing the regex cache for time.strptime(). - -- 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. - -- Patch #848017: Make Cookie more RFC-compliant. Use CRLF as default output - separator and do not output trailing semicola. - -- Patch #1062060: urllib.urlretrieve() now raises a new exception, named - ContentTooShortException, when the actually downloaded size does not - match the Content-Length header. - -- 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 #1192315: Disallow negative arguments to clear() in pdb. - -- Patch #827386: Support absolute source paths in msvccompiler.py. - -- Patch #1105730: Apply the new implementation of commonprefix in posixpath - to ntpath, macpath, os2emxpath and riscospath. - -- 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 #1238170: threading.Thread.__init__ no longer has "kwargs={}" as a - parameter, but uses the usual "kwargs=None". - -- textwrap now processes text chunks at O(n) speed instead of O(n**2). - Patch #1209527 (Contributed by Connelly). - -- urllib2 has now an attribute 'httpresponses' mapping from HTTP status code - to W3C name (404 -> 'Not Found'). RFE #1216944. - -- 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 - it 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 #1108948: Cookie.py produced invalid JavaScript code. - -- The tokenize module now detects and reports indentation errors. - Bug #1224621. - -- The tokenize module has a new untokenize() function to support a full - roundtrip from lexed tokens back to Python sourcecode. In addition, - the generate_tokens() function now accepts a callable argument that - terminates by raising StopIteration. - -- Bug #1196315: fix weakref.WeakValueDictionary constructor. - -- Bug #1213894: os.path.realpath didn't resolve symlinks that were the first - component of the path. - -- Patch #1120353: The xmlrpclib module provides better, more transparent, - support for datetime.{datetime,date,time} objects. With use_datetime set - to True, applications shouldn't have to fiddle with the DateTime wrapper - class at all. - -- distutils.commands.upload was added to support uploading distribution - files to PyPI. - -- distutils.commands.register now encodes the data as UTF-8 before posting - them to PyPI. - -- decimal operator and comparison methods now return NotImplemented - instead of raising a TypeError when interacting with other types. This - allows other classes to implement __radd__ style methods and have them - work as expected. - -- Bug #1163325: Decimal infinities failed to hash. Attempting to - hash a NaN raised an InvalidOperation instead of a TypeError. - -- Patch #918101: Add tarfile open mode r|* for auto-detection of the - stream compression; add, for symmetry reasons, r:* as a synonym of r. - -- Patch #1043890: Add extractall method to tarfile. - -- 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 #645894: Use getrusage for computing the time consumption in - profile.py if available. - -- Patch #1046831: Use get_python_version where appropriate in sysconfig.py. - -- 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 #1110248: SYNC_FLUSH the zlib buffer for GZipFile.flush. - -- Patch #1107973: Allow to iterate over the lines of a tarfile.ExFileObject. - -- Patch #1104111: Alter setup.py --help and --help-commands. - -- Patch #1121234: Properly cleanup _exit and tkerror commands. - -- Patch #1049151: xdrlib now unpacks booleans as True or False. - -- Fixed bug in a NameError bug in cookielib. Patch #1116583. - -- Applied a security fix to SimpleXMLRPCserver (PSF-2005-001). This - disables recursive traversal through instance attributes, which can - be exploited in various ways. - -- Bug #1222790: in SimpleXMLRPCServer, set the reuse-address and close-on-exec - flags on the HTTP listening socket. - -- Bug #792570: SimpleXMLRPCServer had problems if the request grew too large. - Fixed by reading the HTTP body in chunks instead of one big socket.read(). - -- Patches #893642, #1039083: add allow_none, encoding arguments to constructors of - SimpleXMLRPCServer and CGIXMLRPCRequestHandler. - -- Bug #1110478: Revert os.environ.update to do putenv again. - -- Bug #1103844: fix distutils.install.dump_dirs() with negated options. - -- os.{SEEK_SET, SEEK_CUR, SEEK_END} have been added for convenience. - -- Enhancements to the csv module: - - + Dialects are now validated by the underlying C code, better - reflecting its capabilities, and improving its compliance with - PEP 305. - + Dialect parameter parsing has been re-implemented to improve error - reporting. - + quotechar=None and quoting=QUOTE_NONE now work the way PEP 305 - dictates. - + the parser now removes the escapechar prefix from escaped characters. - + when quoting=QUOTE_NONNUMERIC, the writer now tests for numeric - types, rather than any object than can be represented as a numeric. - + when quoting=QUOTE_NONNUMERIC, the reader now casts unquoted fields - to floats. - + reader now allows \r characters to be quoted (previously it only allowed - \n to be quoted). - + writer doublequote handling improved. - + Dialect classes passed to the module are no longer instantiated by - the module before being parsed (the former validation scheme required - this, but the mechanism was unreliable). - + The dialect registry now contains instances of the internal - C-coded dialect type, rather than references to python objects. - + the internal c-coded dialect type is now immutable. - + register_dialect now accepts the same keyword dialect specifications - as the reader and writer, allowing the user to register dialects - without first creating a dialect class. - + a configurable limit to the size of parsed fields has been added - - previously, an unmatched quote character could result in the entire - file being read into the field buffer before an error was reported. - + A new module method csv.field_size_limit() has been added that sets - the parser field size limit (returning the former limit). The initial - limit is 128kB. - + A line_num attribute has been added to the reader object, which tracks - the number of lines read from the source iterator. This is not - the same as the number of records returned, as records can span - multiple lines. - + reader and writer objects were not being registered with the cyclic-GC. - This has been fixed. - -- _DummyThread objects in the threading module now delete self.__block that is - inherited from _Thread since it uses up a lock allocated by 'thread'. The - lock primitives tend to be limited in number and thus should not be wasted on - a _DummyThread object. Fixes bug #1089632. - -- The imghdr module now detects Exif files. - -- StringIO.truncate() now correctly adjusts the size attribute. - (Bug #951915). - -- locale.py now uses an updated locale alias table (built using - Tools/i18n/makelocalealias.py, a tool to parse the X11 locale - alias file); the encoding lookup was enhanced to use Python's - encoding alias table. - -- moved deprecated modules to Lib/lib-old: whrandom, tzparse, statcache. - -- the pickle module no longer accepts the deprecated None option in the - args tuple returned by __reduce__(). - -- optparse now optionally imports gettext. This allows its use in setup.py. - -- the pickle module no longer uses the deprecated bin parameter. - -- the shelve module no longer uses the deprecated binary parameter. - -- the pstats module no longer uses the deprecated ignore() method. - -- the filecmp module no longer uses the deprecated use_statcache argument. - -- 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). - -- heapq.nsmallest() and heapq.nlargest() now support key= arguments with - the same meaning as in list.sort(). - -- 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. - -- The reconvert.quote function can now emit triple-quoted strings. The - reconvert module now has some simple documentation. - -- ``UserString.MutableString`` now supports negative indices in - ``__setitem__`` and ``__delitem__`` - -- Bug #1149508: ``textwrap`` now handles hyphenated numbers (eg. "2004-03-05") - correctly. - -- 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 '*'. - -- Bug #1245379: Add "unicode-1-1-utf-7" as an alias for "utf-7" to - ``encodings.aliases``. - -- ` uu.encode()`` and ``uu.decode()`` now support unicode filenames. - -- Patch #1413711: Certain patterns of differences were making difflib - touch the recursion limit. - -Build ------ - -- Patch #1432345: Make python compile on DragonFly. - -- Build support for Win64-AMD64 was added. - -- Patch #1428494: Prefer linking against ncursesw over ncurses library. - -- Patch #881820: look for openpty and forkpty also in libbsd. - -- The sources of zlib are now part of the Python distribution (zlib 1.2.3). - The zlib module is now builtin on Windows. - -- Use -xcode=pic32 for CCSHARED on Solaris with SunPro. - -- 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. - -- EXTRA_CFLAGS has been introduced as an environment variable to hold compiler - flags that change binary compatibility. Changes were also made to - distutils.sysconfig to also use the environment variable when used during - compilation of the interpreter and of C extensions through distutils. - -- SF patch 1171735: 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. - -- Bug #1158607: Build with --disable-unicode again. - -- spwdmodule.c is built only if either HAVE_GETSPNAM or HAVE_HAVE_GETSPENT is - defined. Discovered as a result of not being able to build on OS X. - -- setup.py now uses the directories specified in LDFLAGS using the -L option - and in CPPFLAGS using the -I option for adding library and include - directories, respectively, for compiling extension modules against. This has - led to the core being compiled using the values in CPPFLAGS. It also removes - the need for the special-casing of both DarwinPorts and Fink for darwin since - the proper directories can be specified in LDFLAGS (``-L/sw/lib`` for Fink, - ``-L/opt/local/lib`` for DarwinPorts) and CPPFLAGS (``-I/sw/include`` for - Fink, ``-I/opt/local/include`` for DarwinPorts). - -- Test in configure.in that checks 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. - -C API ------ - -- Added a C API for set and frozenset objects. - -- Removed PyRange_New(). - -- Patch #1313939: PyUnicode_DecodeCharmap() accepts a unicode string as the - mapping argument now. This string is used as a mapping table. Byte values - greater than the length of the string and 0xFFFE are treated as undefined - mappings. - - -Tests +TO DO ----- -- In test_os, st_?time is now truncated before comparing it with ST_?TIME. - -- Patch #1276356: New resource "urlfetch" is implemented. This enables - even impatient people to run tests that require remote files. - - -Documentation -------------- - -- Bug #1402224: Add warning to dl docs about crashes. - -- Bug #1396471: Document that Windows' ftell() can return invalid - values for text files with UNIX-style line endings. - -- 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. +- Make strings all Unicode. (First have to introduce the bytes type.) -- Bug #1175022: Correct the example code for property(). +- Get rid of classic class implementation. -- Document the IterableUserDict class in the UserDict module. - Closes bug #1166582. +- Get rid of various compatibility-related flags (e.g. division flags). -- 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. - -Mac ---- - - -New platforms -------------- - -- FreeBSD 7 support is added. - - -Tools/Demos ------------ - -- Created Misc/Vim/vim_syntax.py to auto-generate a python.vim file in that - directory for syntax highlighting in Vim. Vim directory was added and placed - vimrc to it (was previous up a level). - -- Added two new files to Tools/scripts: pysource.py, which recursively - finds Python source files, and findnocoding.py, which finds Python - source files that need an encoding declaration. - Patch #784089, credits to Oleg Broytmann. - -- Bug #1072853: pindent.py used an uninitialized variable. - -- Patch #1177597: Correct Complex.__init__. - -- Fixed a display glitch in Pynche, which could cause the right arrow to - wiggle over by a pixel. - -What's New in Python 2.4 final? -=============================== - -*Release date: 30-NOV-2004* - -Core and builtins +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* +- Classic classes are a thing of the past. All classes are new style. -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. +- Exceptions *must* derive from BaseException. -The official name of the new license is the Python Software Foundation -License Version 2. +- Integer division always returns a float. The -Q option is no more. -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" - ``AttributeError`` 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. +- 'as' and 'with' are keywords. -- Bug #1054139 _PyString_Resize() now invalidates its cached hash value. +- Absolute import is the default behavior for 'import foo' etc. 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 <http://darwinports.opendarwin.org/> - -- 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 <BLANKLINE> 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 $Id$), 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 <bluetooth/bluetooth.h> - -- 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 -------- - -- Added a new module: cProfile, a C profiler with the same interface as the - profile module. cProfile avoids some of the drawbacks of the hotshot - profiler and provides a bit more information than the other two profilers. - Based on "lsprof" (patch #1212837). - -- Bug #1266283: The new function "lexists" is now in os.path.__all__. - -- 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. - - -What's New in Python 2.3 final? -=============================== - -*Release date: 29-Jul-2003* - -IDLE ----- - -- Bug 778400: IDLE hangs when selecting "Edit with IDLE" from explorer. - This was unique to Windows, and was fixed by adding an -n switch to - the command the Windows installer creates to execute "Edit with IDLE" - context-menu actions. - -- IDLE displays a new message upon startup: some "personal firewall" - kinds of programs (for example, ZoneAlarm) open a dialog of their - own when any program opens a socket. IDLE does use sockets, talking - on the computer's internal loopback interface. This connection is not - visible on any external interface and no data is sent to or received - from the Internet. So, if you get such a dialog when opening IDLE, - asking whether to let pythonw.exe talk to address 127.0.0.1, say yes, - and rest assured no communication external to your machine is taking - place. If you don't allow it, IDLE won't be able to start. - - -What's New in Python 2.3 release candidate 2? -============================================= - -*Release date: 24-Jul-2003* - -Core and builtins ------------------ - -- It is now possible to import from zipfiles containing additional - data bytes before the zip compatible archive. Zipfiles containing a - comment at the end are still unsupported. - -Extension modules ------------------ - -- A longstanding bug in the parser module's initialization could cause - fatal internal refcount confusion when the module got initialized more - than once. This has been fixed. - -- Fixed memory leak in pyexpat; using the parser's ParseFile() method - with open files that aren't instances of the standard file type - caused an instance of the bound .read() method to be leaked on every - call. - -- Fixed some leaks in the locale module. - -Library -------- - -- Lib/encodings/rot_13.py when used as a script, now more properly - uses the first Python interpreter on your path. - -- Removed caching of TimeRE (and thus LocaleTime) in _strptime.py to - fix a locale related bug in the test suite. Although another patch - was needed to actually fix the problem, the cache code was not - restored. - -IDLE ----- - -- Calltips patches. - -Build ------ - -- For MacOSX, added -mno-fused-madd to BASECFLAGS to fix test_coercion - on Panther (OSX 10.3). - -C API ------ - -Windows -------- - -- The tempfile module could do insane imports on Windows if PYTHONCASEOK - was set, making temp file creation impossible. Repaired. - -- Add a patch to workaround pthread_sigmask() bugs in Cygwin. - -Mac ---- - -- Various fixes to pimp. - -- Scripts runs with pythonw no longer had full window manager access. - -- Don't force boot-disk-only install, for reasons unknown it causes - more problems than it solves. - - -What's New in Python 2.3 release candidate 1? -============================================= - -*Release date: 18-Jul-2003* - -Core and builtins ------------------ - -- The new function sys.getcheckinterval() returns the last value set - by sys.setcheckinterval(). - -- Several bugs in the symbol table phase of the compiler have been - fixed. Errors could be lost and compilation could fail without - reporting an error. SF patch 763201. - -- The interpreter is now more robust about importing the warnings - module. In an executable generated by freeze or similar programs, - earlier versions of 2.3 would fail if the warnings module could - not be found on the file system. Fixes SF bug 771097. - -- A warning about assignments to module attributes that shadow - builtins, present in earlier releases of 2.3, has been removed. - -- It is not possible to create subclasses of builtin types like str - and tuple that define an itemsize. Earlier releases of Python 2.3 - allowed this by mistake, leading to crashes and other problems. - -- The thread_id is now initialized to 0 in a non-thread build. SF bug - 770247. - -- SF bug 762891: "del p[key]" on proxy object no longer raises SystemError. - -Extension modules ------------------ - -- weakref.proxy() can now handle "del obj[i]" for proxy objects - defining __delitem__. Formerly, it generated a SystemError. - -- SSL no longer crashes the interpreter when the remote side disconnects. - -- On Unix the mmap module can again be used to map device files. - -- time.strptime now exclusively uses the Python implementation - contained within the _strptime module. - -- The print slot of weakref proxy objects was removed, because it was - not consistent with the object's repr slot. - -- The mmap module only checks file size for regular files, not - character or block devices. SF patch 708374. - -- The cPickle Pickler garbage collection support was fixed to traverse - the find_class attribute, if present. - -- There are several fixes for the bsddb3 wrapper module. - - bsddb3 no longer crashes if an environment is closed before a cursor - (SF bug 763298). - - The DB and DBEnv set_get_returns_none function was extended to take - a level instead of a boolean flag. The new level 2 means that in - addition, cursor.set()/.get() methods return None instead of raising - an exception. - - A typo was fixed in DBCursor.join_item(), preventing a crash. - -Library -------- - -- distutils now supports MSVC 7.1 - -- doctest now examines all docstrings by default. Previously, it would - skip over functions with private names (as indicated by the underscore - naming convention). The old default created too much of a risk that - user tests were being skipped inadvertently. Note, this change could - break code in the unlikely case that someone had intentionally put - failing tests in the docstrings of private functions. The breakage - is easily fixable by specifying the old behavior when calling testmod() - or Tester(). - -- There were several fixes to the way dumbdbms are closed. It's vital - that a dumbdbm database be closed properly, else the on-disk data - and directory files can be left in mutually inconsistent states. - dumbdbm.py's _Database.__del__() method attempted to close the - database properly, but a shutdown race in _Database._commit() could - prevent this from working, so that a program trusting __del__() to - get the on-disk files in synch could be badly surprised. The race - has been repaired. A sync() method was also added so that shelve - can guarantee data is written to disk. - - The close() method can now be called more than once without complaint. - -- The classes in threading.py are now new-style classes. That they - weren't before was an oversight. - -- The urllib2 digest authentication handlers now define the correct - auth_header. The earlier versions would fail at runtime. - -- SF bug 763023: fix uncaught ZeroDivisionError in difflib ratio methods - when there are no lines. - -- SF bug 763637: fix exception in Tkinter with after_cancel - which could occur with Tk 8.4 - -- SF bug 770601: CGIHTTPServer.py now passes the entire environment - to child processes. - -- SF bug 765238: add filter to fnmatch's __all__. - -- SF bug 748201: make time.strptime() error messages more helpful. - -- SF patch 764470: Do not dump the args attribute of a Fault object in - xmlrpclib. - -- SF patch 549151: urllib and urllib2 now redirect POSTs on 301 - responses. - -- SF patch 766650: The whichdb module was fixed to recognize dbm files - generated by gdbm on OS/2 EMX. - -- SF bugs 763047 and 763052: fixes bug of timezone value being left as - -1 when ``time.tzname[0] == time.tzname[1] and not time.daylight`` - is true when it should only when time.daylight is true. - -- SF bug 764548: re now allows subclasses of str and unicode to be - used as patterns. - -- SF bug 763637: In Tkinter, change after_cancel() to handle tuples - of varying sizes. Tk 8.4 returns a different number of values - than Tk 8.3. - -- SF bug 763023: difflib.ratio() did not catch zero division. - -- The Queue module now has an __all__ attribute. - -Tools/Demos ------------ - -- See Lib/idlelib/NEWS.txt for IDLE news. - -- SF bug 753592: webchecker/wsgui now handles user supplied directories. - -- The trace.py script has been removed. It is now in the standard library. - -Build ------ - -- Python now compiles with -fno-strict-aliasing if possible (SF bug 766696). - -- The socket module compiles on IRIX 6.5.10. - -- An irix64 system is treated the same way as an irix6 system (SF - patch 764560). - -- Several definitions were missing on FreeBSD 5.x unless the - __BSD_VISIBLE symbol was defined. configure now defines it as - needed. - -C API ------ - -- Unicode objects now support mbcs as a built-in encoding, so the C - API can use it without deferring to the encodings package. - -Windows -------- - -- The Windows implementation of PyThread_start_new_thread() never - checked error returns from Windows functions correctly. As a result, - it could claim to start a new thread even when the Microsoft - _beginthread() function failed (due to "too many threads" -- this is - on the order of thousands when it happens). In these cases, the - Python exception :: - - thread.error: can't start new thread - - is raised now. - -- SF bug 766669: Prevent a GPF on interpreter exit when sockets are in - use. The interpreter now calls WSACleanup() from Py_Finalize() - instead of from DLL teardown. - -Mac ---- - -- Bundlebuilder now inherits default values in the right way. It was - previously possible for app bundles to get a type of "BNDL" instead - of "APPL." Other improvements include, a --build-id option to - specify the CFBundleIdentifier and using the --python option to set - the executable in the bundle. - -- Fixed two bugs in MacOSX framework handling. - -- pythonw did not allow user interaction in 2.3rc1, this has been fixed. - -- Python is now compiled with -mno-fused-madd, making all tests pass - on Panther. - -What's New in Python 2.3 beta 2? -================================ - -*Release date: 29-Jun-2003* - -Core and builtins ------------------ - -- A program can now set the environment variable PYTHONINSPECT to some - string value in Python, and cause the interpreter to enter the - interactive prompt at program exit, as if Python had been invoked - with the -i option. - -- list.index() now accepts optional start and stop arguments. Similar - changes were made to UserList.index(). SF feature request 754014. - -- SF patch 751998 fixes an unwanted side effect of the previous fix - for SF bug 742860 (the next item). - -- SF bug 742860: "WeakKeyDictionary __delitem__ uses iterkeys". This - wasn't threadsafe, was very inefficient (expected time O(len(dict)) - instead of O(1)), and could raise a spurious RuntimeError if another - thread mutated the dict during __delitem__, or if a comparison function - mutated it. It also neglected to raise KeyError when the key wasn't - present; didn't raise TypeError when the key wasn't of a weakly - referencable type; and broke various more-or-less obscure dict - invariants by using a sequence of equality comparisons over the whole - set of dict keys instead of computing the key's hash code to narrow - the search to those keys with the same hash code. All of these are - considered to be bugs. A new implementation of __delitem__ repairs all - that, but note that fixing these bugs may change visible behavior in - code relying (whether intentionally or accidentally) on old behavior. - -- SF bug 734869: Fixed a compiler bug that caused a fatal error when - compiling a list comprehension that contained another list comprehension - embedded in a lambda expression. - -- SF bug 705231: builtin pow() no longer lets the platform C pow() - raise -1.0 to integer powers, because (at least) glibc gets it wrong - in some cases. The result should be -1.0 if the power is odd and 1.0 - if the power is even, and any float with a sufficiently large exponent - is (mathematically) an exact even integer. - -- SF bug 759227: A new-style class that implements __nonzero__() must - return a bool or int (but not an int subclass) from that method. This - matches the restriction on classic classes. - -- The encoding attribute has been added for file objects, and set to - the terminal encoding on Unix and Windows. - -- The softspace attribute of file objects became read-only by oversight. - It's writable again. - -- Reverted a 2.3 beta 1 change to iterators for subclasses of list and - tuple. By default, the iterators now access data elements directly - instead of going through __getitem__. If __getitem__ access is - preferred, then __iter__ can be overridden. - -- SF bug 735247: The staticmethod and super types participate in - garbage collection. Before this change, it was possible for leaks to - occur in functions with non-global free variables that used these types. - -Extension modules ------------------ - -- the socket module has a new exception, socket.timeout, to allow - timeouts to be handled separately from other socket errors. - -- SF bug 751276: cPickle has fixed to propagate exceptions raised in - user code. In earlier versions, cPickle caught and ignored any - exception when it performed operations that it expected to raise - specific exceptions like AttributeError. - -- cPickle Pickler and Unpickler objects now participate in garbage - collection. - -- mimetools.choose_boundary() could return duplicate strings at times, - especially likely on Windows. The strings returned are now guaranteed - unique within a single program run. - -- thread.interrupt_main() raises KeyboardInterrupt in the main thread. - dummy_thread has also been modified to try to simulate the behavior. - -- array.array.insert() now treats negative indices as being relative - to the end of the array, just like list.insert() does. (SF bug #739313) - -- The datetime module classes datetime, time, and timedelta are now - properly subclassable. - -- _tkinter.{get|set}busywaitinterval was added. - -- itertools.islice() now accepts stop=None as documented. - Fixes SF bug #730685. - -- the bsddb185 module is built in one restricted instance - - /usr/include/db.h exists and defines HASHVERSION to be 2. This is true - for many BSD-derived systems. - - -Library -------- - -- Some happy doctest extensions from Jim Fulton have been added to - doctest.py. These are already being used in Zope3. The two - primary ones: - - doctest.debug(module, name) extracts the doctests from the named object - in the given module, puts them in a temp file, and starts pdb running - on that file. This is great when a doctest fails. - - doctest.DocTestSuite(module=None) returns a synthesized unittest - TestSuite instance, to be run by the unittest framework, which - runs all the doctests in the module. This allows writing tests in - doctest style (which can be clearer and shorter than writing tests - in unittest style), without losing unittest's powerful testing - framework features (which doctest lacks). - -- For compatibility with doctests created before 2.3, if an expected - output block consists solely of "1" and the actual output block - consists solely of "True", it's accepted as a match; similarly - for "0" and "False". This is quite un-doctest-like, but is practical. - The behavior can be disabled by passing the new doctest module - constant DONT_ACCEPT_TRUE_FOR_1 to the new optionflags optional - argument. - -- ZipFile.testzip() now only traps BadZipfile exceptions. Previously, - a bare except caught to much and reported all errors as a problem - in the archive. - -- The logging module now has a new function, makeLogRecord() making - LogHandler easier to interact with DatagramHandler and SocketHandler. - -- The cgitb module has been extended to support plain text display (SF patch - 569574). - -- A brand new version of IDLE (from the IDLEfork project at - SourceForge) is now included as Lib/idlelib. The old Tools/idle is - no more. - -- Added a new module: trace (documentation missing). This module used - to be distributed in Tools/scripts. It uses sys.settrace() to trace - code execution -- either function calls or individual lines. It can - generate tracing output during execution or a post-mortem report of - code coverage. - -- The threading module has new functions settrace() and setprofile() - that cooperate with the functions of the same name in the sys - module. A function registered with the threading module will - be used for all threads it creates. The new trace module uses this - to provide tracing for code running in threads. - -- copy.py: applied SF patch 707900, fixing bug 702858, by Steven - Taschuk. Copying a new-style class that had a reference to itself - didn't work. (The same thing worked fine for old-style classes.) - Builtin functions are now treated as atomic, fixing bug #746304. - -- difflib.py has two new functions: context_diff() and unified_diff(). - -- More fixes to urllib (SF 549151): (a) When redirecting, always use - GET. This is common practice and more-or-less sanctioned by the - HTTP standard. (b) Add a handler for 307 redirection, which becomes - an error for POST, but a regular redirect for GET and HEAD - -- Added optional 'onerror' argument to os.walk(), to control error - handling. - -- inspect.is{method|data}descriptor was added, to allow pydoc display - __doc__ of data descriptors. - -- Fixed socket speed loss caused by use of the _socketobject wrapper class - in socket.py. - -- timeit.py now checks the current directory for imports. - -- urllib2.py now knows how to order proxy classes, so the user doesn't - have to insert it in front of other classes, nor do dirty tricks like - inserting a "dummy" HTTPHandler after a ProxyHandler when building an - opener with proxy support. - -- Iterators have been added for dbm keys. - -- random.Random objects can now be pickled. - -Tools/Demos ------------ - -- pydoc now offers help on keywords and topics. - -- Tools/idle is gone; long live Lib/idlelib. - -- diff.py prints file diffs in context, unified, or ndiff formats, - providing a command line interface to difflib.py. - -- texcheck.py is a new script for making a rough validation of Python LaTeX - files. - -Build ------ - -- Setting DESTDIR during 'make install' now allows specifying a - different root directory. - -C API ------ - -- PyType_Ready(): If a type declares that it participates in gc - (Py_TPFLAGS_HAVE_GC), and its base class does not, and its base class's - tp_free slot is the default _PyObject_Del, and type does not define - a tp_free slot itself, _PyObject_GC_Del is assigned to type->tp_free. - Previously _PyObject_Del was inherited, which could at best lead to a - segfault. In addition, if even after this magic the type's tp_free - slot is _PyObject_Del or NULL, and the type is a base type - (Py_TPFLAGS_BASETYPE), TypeError is raised: since the type is a base - type, its dealloc function must call type->tp_free, and since the type - is gc'able, tp_free must not be NULL or _PyObject_Del. - -- PyThreadState_SetAsyncExc(): A new API (deliberately accessible only - from C) to interrupt a thread by sending it an exception. It is - intentional that you have to write your own C extension to call it - from Python. - - -New platforms -------------- - -None this time. - -Tests ------ - -- test_imp rewritten so that it doesn't raise RuntimeError if run as a - side effect of being imported ("import test.autotest"). - -Windows -------- - -- The Windows installer ships with Tcl/Tk 8.4.3 (upgraded from 8.4.1). - -- The installer always suggested that Python be installed on the C: - drive, due to a hardcoded "C:" generated by the Wise installation - wizard. People with machines where C: is not the system drive - usually want Python installed on whichever drive is their system drive - instead. We removed the hardcoded "C:", and two testers on machines - where C: is not the system drive report that the installer now - suggests their system drive. Note that you can always select the - directory you want in the "Select Destination Directory" dialog -- - that's what it's for. - -Mac ---- - -- There's a new module called "autoGIL", which offers a mechanism to - automatically release the Global Interpreter Lock when an event loop - goes to sleep, allowing other threads to run. It's currently only - supported on OSX, in the Mach-O version. -- The OSA modules now allow direct access to properties of the - toplevel application class (in AppleScript terminology). -- The Package Manager can now update itself. - -SourceForge Bugs and Patches Applied ------------------------------------- - -430160, 471893, 501716, 542562, 549151, 569574, 595837, 596434, -598163, 604210, 604716, 610332, 612627, 614770, 620190, 621891, -622042, 639139, 640236, 644345, 649742, 649742, 658233, 660022, -661318, 661676, 662807, 662923, 666219, 672855, 678325, 682347, -683486, 684981, 685773, 686254, 692776, 692959, 693094, 696777, -697989, 700827, 703666, 708495, 708604, 708901, 710733, 711902, -713722, 715782, 718286, 719359, 719367, 723136, 723831, 723962, -724588, 724767, 724767, 725942, 726150, 726446, 726869, 727051, -727719, 727719, 727805, 728277, 728563, 728656, 729096, 729103, -729293, 729297, 729300, 729317, 729395, 729622, 729817, 730170, -730296, 730594, 730685, 730826, 730963, 731209, 731403, 731504, -731514, 731626, 731635, 731643, 731644, 731644, 731689, 732124, -732143, 732234, 732284, 732284, 732479, 732761, 732783, 732951, -733667, 733781, 734118, 734231, 734869, 735051, 735293, 735527, -735613, 735694, 736962, 736962, 737970, 738066, 739313, 740055, -740234, 740301, 741806, 742126, 742741, 742860, 742860, 742911, -744041, 744104, 744238, 744687, 744877, 745055, 745478, 745525, -745620, 746012, 746304, 746366, 746801, 746953, 747348, 747667, -747954, 748846, 748849, 748973, 748975, 749191, 749210, 749759, -749831, 749911, 750008, 750092, 750542, 750595, 751038, 751107, -751276, 751451, 751916, 751941, 751956, 751998, 752671, 753451, -753602, 753617, 753845, 753925, 754014, 754340, 754447, 755031, -755087, 755147, 755245, 755683, 755987, 756032, 756996, 757058, -757229, 757818, 757821, 757822, 758112, 758910, 759227, 759889, -760257, 760703, 760792, 761104, 761337, 761519, 761830, 762455 - - -What's New in Python 2.3 beta 1? -================================ - -*Release date: 25-Apr-2003* - -Core and builtins ------------------ - -- New format codes B, H, I, k and K have been implemented for - PyArg_ParseTuple and PyBuild_Value. - -- New builtin function sum(seq, start=0) returns the sum of all the - items in iterable object seq, plus start (items are normally numbers, - and cannot be strings). - -- bool() called without arguments now returns False rather than - raising an exception. This is consistent with calling the - constructors for the other builtin types -- called without argument - they all return the false value of that type. (SF patch #724135) - -- In support of PEP 269 (making the pgen parser generator accessible - from Python), some changes to the pgen code structure were made; a - few files that used to be linked only with pgen are now linked with - Python itself. - -- The repr() of a weakref object now shows the __name__ attribute of - the referenced object, if it has one. - -- super() no longer ignores data descriptors, except __class__. See - the thread started at - http://mail.python.org/pipermail/python-dev/2003-April/034338.html - -- list.insert(i, x) now interprets negative i as it would be - interpreted by slicing, so negative values count from the end of the - list. This was the only place where such an interpretation was not - placed on a list index. - -- range() now works even if the arguments are longs with magnitude - larger than sys.maxint, as long as the total length of the sequence - fits. E.g., range(2**100, 2**101, 2**100) is the following list: - [1267650600228229401496703205376L]. (SF patch #707427.) - -- Some horridly obscure problems were fixed involving interaction - between garbage collection and old-style classes with "ambitious" - getattr hooks. If an old-style instance didn't have a __del__ method, - but did have a __getattr__ hook, and the instance became reachable - only from an unreachable cycle, and the hook resurrected or deleted - unreachable objects when asked to resolve "__del__", anything up to - a segfault could happen. That's been repaired. - -- dict.pop now takes an optional argument specifying a default - value to return if the key is not in the dict. If a default is not - given and the key is not found, a KeyError will still be raised. - Parallel changes were made to UserDict.UserDict and UserDict.DictMixin. - [SF patch #693753] (contributed by Michael Stone.) - -- sys.getfilesystemencoding() was added to expose - Py_FileSystemDefaultEncoding. - -- New function sys.exc_clear() clears the current exception. This is - rarely needed, but can sometimes be useful to release objects - referenced by the traceback held in sys.exc_info()[2]. (SF patch - #693195.) - -- On 64-bit systems, a dictionary could contain duplicate long/int keys - if the key value was larger than 2**32. See SF bug #689659. - -- Fixed SF bug #663074. The codec system was using global static - variables to store internal data. As a result, any attempts to use the - unicode system with multiple active interpreters, or successive - interpreter executions, would fail. - -- "%c" % u"a" now returns a unicode string instead of raising a - TypeError. u"%c" % 0xffffffff now raises a OverflowError instead - of a ValueError to be consistent with "%c" % 256. See SF patch #710127. - -Extension modules ------------------ - -- The socket module now provides the functions inet_pton and inet_ntop - for converting between string and packed representation of IP - addresses. There is also a new module variable, has_ipv6, which is - True iff the current Python has IPv6 support. See SF patch #658327. - -- Tkinter wrappers around Tcl variables now pass objects directly - to Tcl, instead of first converting them to strings. - -- The .*? pattern in the re module is now special-cased to avoid the - recursion limit. (SF patch #720991 -- many thanks to Gary Herron - and Greg Chapman.) - -- New function sys.call_tracing() allows pdb to debug code - recursively. - -- New function gc.get_referents(obj) returns a list of objects - directly referenced by obj. In effect, it exposes what the object's - tp_traverse slot does, and can be helpful when debugging memory - leaks. - -- The iconv module has been removed from this release. - -- The platform-independent routines for packing floats in IEEE formats - (struct.pack's <f, >f, <d, and >d codes; pickle and cPickle's protocol 1 - pickling of floats) ignored that rounding can cause a carry to - propagate. The worst consequence was that, in rare cases, <f and >f - could produce strings that, when unpacked again, were a factor of 2 - away from the original float. This has been fixed. See SF bug - #705836. - -- New function time.tzset() provides access to the C library tzset() - function, if supported. (SF patch #675422.) - -- Using createfilehandler, deletefilehandler, createtimerhandler functions - on Tkinter.tkinter (_tkinter module) no longer crashes the interpreter. - See SF bug #692416. - -- Modified the fcntl.ioctl() function to allow modification of a passed - mutable buffer (for details see the reference documentation). - -- Made user requested changes to the itertools module. - Subsumed the times() function into repeat(). - Added chain() and cycle(). - -- The rotor module is now deprecated; the encryption algorithm it uses - is not believed to be secure, and including crypto code with Python - has implications for exporting and importing it in various countries. - -- The socket module now always uses the _socketobject wrapper class, even on - platforms which have dup(2). The makefile() method is built directly - on top of the socket without duplicating the file descriptor, allowing - timeouts to work properly. - -Library -------- - -- New generator function os.walk() is an easy-to-use alternative to - os.path.walk(). See os module docs for details. os.path.walk() - isn't deprecated at this time, but may become deprecated in a - future release. - -- Added new module "platform" which provides a wide range of tools - for querying platform dependent features. - -- netrc now allows ASCII punctuation characters in passwords. - -- shelve now supports the optional writeback argument, and exposes - pickle protocol versions. - -- Several methods of nntplib.NNTP have grown an optional file argument - which specifies a file where to divert the command's output - (already supported by the body() method). (SF patch #720468) - -- The self-documenting XML server library DocXMLRPCServer was added. - -- Support for internationalized domain names has been added through - the 'idna' and 'punycode' encodings, the 'stringprep' module, the - 'mkstringprep' tool, and enhancements to the socket and httplib - modules. - -- htmlentitydefs has two new dictionaries: name2codepoint maps - HTML entity names to Unicode codepoints (as integers). - codepoint2name is the reverse mapping. See SF patch #722017. - -- pdb has a new command, "debug", which lets you step through - arbitrary code from the debugger's (pdb) prompt. - -- unittest.failUnlessEqual and its equivalent unittest.assertEqual now - return 'not a == b' rather than 'a != b'. This gives the desired - result for classes that define __eq__ without defining __ne__. - -- sgmllib now supports SGML marked sections, in particular the - MS Office extensions. - -- The urllib module now offers support for the iterator protocol. - SF patch 698520 contributed by Brett Cannon. - -- New module timeit provides a simple framework for timing the - execution speed of expressions and statements. - -- sets.Set objects now support mixed-type __eq__ and __ne__, instead - of raising TypeError. If x is a Set object and y is a non-Set object, - x == y is False, and x != y is True. This is akin to the change made - for mixed-type comparisons of datetime objects in 2.3a2; more info - about the rationale is in the NEWS entry for that. See also SF bug - report <http://www.python.org/sf/693121>. - -- On Unix platforms, if os.listdir() is called with a Unicode argument, - it now returns Unicode strings. (This behavior was added earlier - to the Windows NT/2k/XP version of os.listdir().) - -- Distutils: both 'py_modules' and 'packages' keywords can now be specified - in core.setup(). Previously you could supply one or the other, but - not both of them. (SF patch #695090 from Bernhard Herzog) - -- New csv package makes it easy to read/write CSV files. - -- Module shlex has been extended to allow posix-like shell parsings, - including a split() function for easy spliting of quoted strings and - commands. An iterator interface was also implemented. - -Tools/Demos ------------ - -- New script combinerefs.py helps analyze new PYTHONDUMPREFS output. - See the module docstring for details. - -Build ------ - -- Fix problem building on OSF1 because the compiler only accepted - preprocessor directives that start in column 1. (SF bug #691793.) - -C API ------ - -- Added PyGC_Collect(), equivalent to calling gc.collect(). - -- PyThreadState_GetDict() was changed not to raise an exception or - issue a fatal error when no current thread state is available. This - makes it possible to print dictionaries when no thread is active. - -- LONG_LONG was renamed to PY_LONG_LONG. Extensions that use this and - need compatibility with previous versions can use this: - - #ifndef PY_LONG_LONG - #define PY_LONG_LONG LONG_LONG - #endif - -- Added PyObject_SelfIter() to fill the tp_iter slot for the - typical case where the method returns its self argument. - -- The extended type structure used for heap types (new-style - classes defined by Python code using a class statement) is now - exported from object.h as PyHeapTypeObject. (SF patch #696193.) - -New platforms -------------- - -None this time. - -Tests ------ - -- test_timeout now requires -u network to be passed to regrtest to run. - See SF bug #692988. - -Windows -------- - -- os.fsync() now exists on Windows, and calls the Microsoft _commit() - function. - -- New function winsound.MessageBeep() wraps the Win32 API - MessageBeep(). - -Mac ---- - -- os.listdir() now returns Unicode strings on MacOS X when called with - a Unicode argument. See the general news item under "Library". - -- A new method MacOS.WMAvailable() returns true if it is safe to access - the window manager, false otherwise. - -- EasyDialogs dialogs are now movable-modal, and if the application is - currently in the background they will ask to be moved to the foreground - before displaying. - -- OSA Scripting support has improved a lot, and gensuitemodule.py can now - be used by mere mortals. The documentation is now also more or less - complete. - -- The IDE (in a framework build) now includes introductory documentation - in Apple Help Viewer format. - - -What's New in Python 2.3 alpha 2? -================================= - -*Release date: 19-Feb-2003* - -Core and builtins ------------------ - -- Negative positions returned from PEP 293 error callbacks are now - treated as being relative to the end of the input string. Positions - that are out of bounds raise an IndexError. - -- sys.path[0] (the directory from which the script is loaded) is now - turned into an absolute pathname, unless it is the empty string. - (SF patch #664376.) - -- Finally fixed the bug in compile() and exec where a string ending - with an indented code block but no newline would raise SyntaxError. - This would have been a four-line change in parsetok.c... Except - codeop.py depends on this behavior, so a compilation flag had to be - invented that causes the tokenizer to revert to the old behavior; - this required extra changes to 2 .h files, 2 .c files, and 2 .py - files. (Fixes SF bug #501622.) - -- If a new-style class defines neither __new__ nor __init__, its - constructor would ignore all arguments. This is changed now: the - constructor refuses arguments in this case. This might break code - that worked under Python 2.2. The simplest fix is to add a no-op - __init__: ``def __init__(self, *args, **kw): pass``. - -- Through a bytecode optimizer bug (and I bet you didn't even know - Python *had* a bytecode optimizer :-), "unsigned" hex/oct constants - with a leading minus sign would come out with the wrong sign. - ("Unsigned" hex/oct constants are those with a face value in the - range sys.maxint+1 through sys.maxint*2+1, inclusive; these have - always been interpreted as negative numbers through sign folding.) - E.g. 0xffffffff is -1, and -(0xffffffff) is 1, but -0xffffffff would - come out as -4294967295. This was the case in Python 2.2 through - 2.2.2 and 2.3a1, and in Python 2.4 it will once again have that - value, but according to PEP 237 it really needs to be 1 now. This - will be backported to Python 2.2.3 a well. (SF #660455) - -- int(s, base) sometimes sign-folds hex and oct constants; it only - does this when base is 0 and s.strip() starts with a '0'. When the - sign is actually folded, as in int("0xffffffff", 0) on a 32-bit - machine, which returns -1, a FutureWarning is now issued; in Python - 2.4, this will return 4294967295L, as do int("+0xffffffff", 0) and - int("0xffffffff", 16) right now. (PEP 347) - -- super(X, x): x may now be a proxy for an X instance, i.e. - issubclass(x.__class__, X) but not issubclass(type(x), X). - -- isinstance(x, X): if X is a new-style class, this is now equivalent - to issubclass(type(x), X) or issubclass(x.__class__, X). Previously - only type(x) was tested. (For classic classes this was already the - case.) - -- compile(), eval() and the exec statement now fully support source code - passed as unicode strings. - -- int subclasses can be initialized with longs if the value fits in an int. - See SF bug #683467. - -- long(string, base) takes time linear in len(string) when base is a power - of 2 now. It used to take time quadratic in len(string). - -- filter returns now Unicode results for Unicode arguments. - -- raw_input can now return Unicode objects. - -- List objects' sort() method now accepts None as the comparison function. - Passing None is semantically identical to calling sort() with no - arguments. - -- Fixed crash when printing a subclass of str and __str__ returned self. - See SF bug #667147. - -- Fixed an invalid RuntimeWarning and an undetected error when trying - to convert a long integer into a float which couldn't fit. - See SF bug #676155. - -- Function objects now have a __module__ attribute that is bound to - the name of the module in which the function was defined. This - applies for C functions and methods as well as functions and methods - defined in Python. This attribute is used by pickle.whichmodule(), - which changes the behavior of whichmodule slightly. In Python 2.2 - whichmodule() returns "__main__" for functions that are not defined - at the top-level of a module (examples: methods, nested functions). - Now whichmodule() will return the proper module name. - -Extension modules ------------------ - -- operator.isNumberType() now checks that the object has a nb_int or - nb_float slot, rather than simply checking whether it has a non-NULL - tp_as_number pointer. - -- The imp module now has ways to acquire and release the "import - lock": imp.acquire_lock() and imp.release_lock(). Note: this is a - reentrant lock, so releasing the lock only truly releases it when - this is the last release_lock() call. You can check with - imp.lock_held(). (SF bug #580952 and patch #683257.) - -- Change to cPickle to match pickle.py (see below and PEP 307). - -- Fix some bugs in the parser module. SF bug #678518. - -- Thanks to Scott David Daniels, a subtle bug in how the zlib - extension implemented flush() was fixed. Scott also rewrote the - zlib test suite using the unittest module. (SF bug #640230 and - patch #678531.) - -- Added an itertools module containing high speed, memory efficient - looping constructs inspired by tools from Haskell and SML. - -- The SSL module now handles sockets with a timeout set correctly (SF - patch #675750, fixing SF bug #675552). - -- os/posixmodule has grown the sysexits.h constants (EX_OK and friends). - -- Fixed broken threadstate swap in readline that could cause fatal - errors when a readline hook was being invoked while a background - thread was active. (SF bugs #660476 and #513033.) - -- fcntl now exposes the strops.h I_* constants. - -- Fix a crash on Solaris that occurred when calling close() on - an mmap'ed file which was already closed. (SF patch #665913) - -- Fixed several serious bugs in the zipimport implementation. - -- datetime changes: - - The date class is now properly subclassable. (SF bug #720908) - - The datetime and datetimetz classes have been collapsed into a single - datetime class, and likewise the time and timetz classes into a single - time class. Previously, a datetimetz object with tzinfo=None acted - exactly like a datetime object, and similarly for timetz. This wasn't - enough of a difference to justify distinct classes, and life is simpler - now. - - today() and now() now round system timestamps to the closest - microsecond <http://www.python.org/sf/661086>. This repairs an - irritation most likely seen on Windows systems. - - In dt.astimezone(tz), if tz.utcoffset(dt) returns a duration, - ValueError is raised if tz.dst(dt) returns None (2.3a1 treated it - as 0 instead, but a tzinfo subclass wishing to participate in - time zone conversion has to take a stand on whether it supports - DST; if you don't care about DST, then code dst() to return 0 minutes, - meaning that DST is never in effect). - - The tzinfo methods utcoffset() and dst() must return a timedelta object - (or None) now. In 2.3a1 they could also return an int or long, but that - was an unhelpfully redundant leftover from an earlier version wherein - they couldn't return a timedelta. TOOWTDI. - - The example tzinfo class for local time had a bug. It was replaced - by a later example coded by Guido. - - datetime.astimezone(tz) no longer raises an exception when the - input datetime has no UTC equivalent in tz. For typical "hybrid" time - zones (a single tzinfo subclass modeling both standard and daylight - time), this case can arise one hour per year, at the hour daylight time - ends. See new docs for details. In short, the new behavior mimics - the local wall clock's behavior of repeating an hour in local time. - - dt.astimezone() can no longer be used to convert between naive and aware - datetime objects. If you merely want to attach, or remove, a tzinfo - object, without any conversion of date and time members, use - dt.replace(tzinfo=whatever) instead, where "whatever" is None or a - tzinfo subclass instance. - - A new method tzinfo.fromutc(dt) can be overridden in tzinfo subclasses - to give complete control over how a UTC time is to be converted to - a local time. The default astimezone() implementation calls fromutc() - as its last step, so a tzinfo subclass can affect that too by overriding - fromutc(). It's expected that the default fromutc() implementation will - be suitable as-is for "almost all" time zone subclasses, but the - creativity of political time zone fiddling appears unbounded -- fromutc() - allows the highly motivated to emulate any scheme expressible in Python. - - datetime.now(): The optional tzinfo argument was undocumented (that's - repaired), and its name was changed to tz ("tzinfo" is overloaded enough - already). With a tz argument, now(tz) used to return the local date - and time, and attach tz to it, without any conversion of date and time - members. This was less than useful. Now now(tz) returns the current - date and time as local time in tz's time zone, akin to :: - - tz.fromutc(datetime.utcnow().replace(tzinfo=utc)) - - where "utc" is an instance of a tzinfo subclass modeling UTC. Without - a tz argument, now() continues to return the current local date and time, - as a naive datetime object. - - datetime.fromtimestamp(): Like datetime.now() above, this had less than - useful behavior when the optional tinzo argument was specified. See - also SF bug report <http://www.python.org/sf/660872>. - - date and datetime comparison: In order to prevent comparison from - falling back to the default compare-object-addresses strategy, these - raised TypeError whenever they didn't understand the other object type. - They still do, except when the other object has a "timetuple" attribute, - in which case they return NotImplemented now. This gives other - datetime objects (e.g., mxDateTime) a chance to intercept the - comparison. - - date, time, datetime and timedelta comparison: When the exception - for mixed-type comparisons in the last paragraph doesn't apply, if - the comparison is == then False is returned, and if the comparison is - != then True is returned. Because dict lookup and the "in" operator - only invoke __eq__, this allows, for example, :: - - if some_datetime in some_sequence: - - and :: - - some_dict[some_timedelta] = whatever - - to work as expected, without raising TypeError just because the - sequence is heterogeneous, or the dict has mixed-type keys. [This - seems like a good idea to implement for all mixed-type comparisons - that don't want to allow falling back to address comparison.] - - The constructors building a datetime from a timestamp could raise - ValueError if the platform C localtime()/gmtime() inserted "leap - seconds". Leap seconds are ignored now. On such platforms, it's - possible to have timestamps that differ by a second, yet where - datetimes constructed from them are equal. - - The pickle format of date, time and datetime objects has changed - completely. The undocumented pickler and unpickler functions no - longer exist. The undocumented __setstate__() and __getstate__() - methods no longer exist either. - -Library -------- - -- The logging module was updated slightly; the WARN level was renamed - to WARNING, and the matching function/method warn() to warning(). - -- The pickle and cPickle modules were updated with a new pickling - protocol (documented by pickletools.py, see below) and several - extensions to the pickle customization API (__reduce__, __setstate__ - etc.). The copy module now uses more of the pickle customization - API to copy objects that don't implement __copy__ or __deepcopy__. - See PEP 307 for details. - -- The distutils "register" command now uses http://www.python.org/pypi - as the default repository. (See PEP 301.) - -- the platform dependent path related variables sep, altsep, extsep, - pathsep, curdir, pardir and defpath are now defined in the platform - dependent path modules (e.g. ntpath.py) rather than os.py, so these - variables are now available via os.path. They continue to be - available from the os module. - (see <http://www.python.org/sf/680789>). - -- array.array was added to the types repr.py knows about (see - <http://www.python.org/sf/680789>). - -- The new pickletools.py contains lots of documentation about pickle - internals, and supplies some helpers for working with pickles, such as - a symbolic pickle disassembler. - -- Xmlrpclib.py now supports the builtin boolean type. - -- py_compile has a new 'doraise' flag and a new PyCompileError - exception. - -- SimpleXMLRPCServer now supports CGI through the CGIXMLRPCRequestHandler - class. - -- The sets module now raises TypeError in __cmp__, to clarify that - sets are not intended to be three-way-compared; the comparison - operators are overloaded as subset/superset tests. - -- Bastion.py and rexec.py are disabled. These modules are not safe in - Python 2.2. or 2.3. - -- realpath is now exported when doing ``from poxixpath import *``. - It is also exported for ntpath, macpath, and os2emxpath. - See SF bug #659228. - -- New module tarfile from Lars Gustäbel provides a comprehensive interface - to tar archive files with transparent gzip and bzip2 compression. - See SF patch #651082. - -- urlparse can now parse imap:// URLs. See SF feature request #618024. - -- Tkinter.Canvas.scan_dragto() provides an optional parameter to support - the gain value which is passed to Tk. SF bug# 602259. - -- Fix logging.handlers.SysLogHandler protocol when using UNIX domain sockets. - See SF patch #642974. - -- The dospath module was deleted. Use the ntpath module when manipulating - DOS paths from other platforms. - -Tools/Demos ------------ - -- Two new scripts (db2pickle.py and pickle2db.py) were added to the - Tools/scripts directory to facilitate conversion from the old bsddb module - to the new one. While the user-visible API of the new module is - compatible with the old one, it's likely that the version of the - underlying database library has changed. To convert from the old library, - run the db2pickle.py script using the old version of Python to convert it - to a pickle file. After upgrading Python, run the pickle2db.py script - using the new version of Python to reconstitute your database. For - example: - - % python2.2 db2pickle.py -h some.db > some.pickle - % python2.3 pickle2db.py -h some.db.new < some.pickle - - Run the scripts without any args to get a usage message. - - -Build ------ - -- The audio driver tests (test_ossaudiodev.py and - test_linuxaudiodev.py) are no longer run by default. This is - because they don't always work, depending on your hardware and - software. To run these tests, you must use an invocation like :: - - ./python Lib/test/regrtest.py -u audio test_ossaudiodev - -- On systems which build using the configure script, compiler flags which - used to be lumped together using the OPT flag have been split into two - groups, OPT and BASECFLAGS. OPT is meant to carry just optimization- and - debug-related flags like "-g" and "-O3". BASECFLAGS is meant to carry - compiler flags that are required to get a clean compile. On some - platforms (many Linux flavors in particular) BASECFLAGS will be empty by - default. On others, such as Mac OS X and SCO, it will contain required - flags. This change allows people building Python to override OPT without - fear of clobbering compiler flags which are required to get a clean build. - -- On Darwin/Mac OS X platforms, /sw/lib and /sw/include are added to the - relevant search lists in setup.py. This allows users building Python to - take advantage of the many packages available from the fink project - <http://fink.sf.net/>. - -- A new Makefile target, scriptsinstall, installs a number of useful scripts - from the Tools/scripts directory. - -C API ------ - -- PyEval_GetFrame() is now declared to return a ``PyFrameObject *`` - instead of a plain ``PyObject *``. (SF patch #686601.) - -- PyNumber_Check() now checks that the object has a nb_int or nb_float - slot, rather than simply checking whether it has a non-NULL - tp_as_number pointer. - -- A C type that inherits from a base type that defines tp_as_buffer - will now inherit the tp_as_buffer pointer if it doesn't define one. - (SF #681367) - -- The PyArg_Parse functions now issue a DeprecationWarning if a float - argument is provided when an integer is specified (this affects the 'b', - 'B', 'h', 'H', 'i', and 'l' codes). Future versions of Python will - raise a TypeError. - -Tests ------ - -- Several tests weren't being run from regrtest.py (test_timeout.py, - test_tarfile.py, test_netrc.py, test_multifile.py, - test_importhooks.py and test_imp.py). Now they are. (Note to - developers: please read Lib/test/README when creating a new test, to - make sure to do it right! All tests need to use either unittest or - pydoc.) - -- Added test_posix.py, a test suite for the posix module. - -- Added test_hexoct.py, a test suite for hex/oct constant folding. - -Windows -------- - -- The timeout code for socket connect() didn't work right; this has - now been fixed. test_timeout.py should pass (at least most of the - time). - -- distutils' msvccompiler class now passes the preprocessor options to - the resource compiler. See SF patch #669198. - -- The bsddb module now ships with Sleepycat's 4.1.25.NC, the latest - release without strong cryptography. - -- sys.path[0], if it contains a directory name, is now always an - absolute pathname. (SF patch #664376.) - -- The new logging package is now installed by the Windows installer. It - wasn't in 2.3a1 due to oversight. - Mac --- -- There are new dialogs EasyDialogs.AskFileForOpen, AskFileForSave - and AskFolder. The old macfs.StandardGetFile and friends are deprecated. - -- Most of the standard library now uses pathnames or FSRefs in preference - of FSSpecs, and use the underlying Carbon.File and Carbon.Folder modules - in stead of macfs. macfs will probably be deprecated in the future. - -- Type Carbon.File.FSCatalogInfo and supporting methods have been implemented. - This also makes macfs.FSSpec.SetDates() work again. - -- There is a new module pimp, the package install manager for Python, and - accompanying applet PackageManager. These allow you to easily download - and install pretested extension packages either in source or binary - form. Only in MacPython-OSX. - -- Applets are now built with bundlebuilder in MacPython-OSX, which should make - them more robust and also provides a path towards BuildApplication. The - downside of this change is that applets can no longer be run from the - Terminal window, this will hopefully be fixed in the 2.3b1. - - -What's New in Python 2.3 alpha 1? -================================= - -*Release date: 31-Dec-2002* - -Type/class unification and new-style classes --------------------------------------------- - -- One can now assign to __bases__ and __name__ of new-style classes. - -- dict() now accepts keyword arguments so that dict(one=1, two=2) - is the equivalent of {"one": 1, "two": 2}. Accordingly, - the existing (but undocumented) 'items' keyword argument has - been eliminated. This means that dict(items=someMapping) now has - a different meaning than before. - -- int() now returns a long object if the argument is outside the - integer range, so int("4" * 1000), int(1e200) and int(1L<<1000) will - all return long objects instead of raising an OverflowError. - -- Assignment to __class__ is disallowed if either the old or the new - class is a statically allocated type object (such as defined by an - extension module). This prevents anomalies like 2.__class__ = bool. - -- New-style object creation and deallocation have been sped up - significantly; they are now faster than classic instance creation - and deallocation. - -- The __slots__ variable can now mention "private" names, and the - right thing will happen (e.g. __slots__ = ["__foo"]). - -- The built-ins slice() and buffer() are now callable types. The - types classobj (formerly class), code, function, instance, and - instancemethod (formerly instance-method), which have no built-in - names but are accessible through the types module, are now also - callable. The type dict-proxy is renamed to dictproxy. - -- Cycles going through the __class__ link of a new-style instance are - now detected by the garbage collector. - -- Classes using __slots__ are now properly garbage collected. - [SF bug 519621] - -- Tightened the __slots__ rules: a slot name must be a valid Python - identifier. - -- The constructor for the module type now requires a name argument and - takes an optional docstring argument. Previously, this constructor - ignored its arguments. As a consequence, deriving a class from a - module (not from the module type) is now illegal; previously this - created an unnamed module, just like invoking the module type did. - [SF bug 563060] - -- A new type object, 'basestring', is added. This is a common base type - for 'str' and 'unicode', and can be used instead of - types.StringTypes, e.g. to test whether something is "a string": - isinstance(x, basestring) is True for Unicode and 8-bit strings. This - is an abstract base class and cannot be instantiated directly. - -- Changed new-style class instantiation so that when C's __new__ - method returns something that's not a C instance, its __init__ is - not called. [SF bug #537450] - -- Fixed super() to work correctly with class methods. [SF bug #535444] - -- If you try to pickle an instance of a class that has __slots__ but - doesn't define or override __getstate__, a TypeError is now raised. - This is done by adding a bozo __getstate__ to the class that always - raises TypeError. (Before, this would appear to be pickled, but the - state of the slots would be lost.) - -Core and builtins ------------------ - -- Import from zipfiles is now supported. The name of a zipfile placed - on sys.path causes the import statement to look for importable Python - modules (with .py, pyc and .pyo extensions) and packages inside the - zipfile. The zipfile import follows the specification (though not - the sample implementation) of PEP 273. The semantics of __path__ are - compatible with those that have been implemented in Jython since - Jython 2.1. - -- PEP 302 has been accepted. Although it was initially developed to - support zipimport, it offers a new, general import hook mechanism. - Several new variables have been added to the sys module: - sys.meta_path, sys.path_hooks, and sys.path_importer_cache; these - make extending the import statement much more convenient than - overriding the __import__ built-in function. For a description of - these, see PEP 302. - -- A frame object's f_lineno attribute can now be written to from a - trace function to change which line will execute next. A command to - exploit this from pdb has been added. [SF patch #643835] - -- The _codecs support module for codecs.py was turned into a builtin - module to assure that at least the builtin codecs are available - to the Python parser for source code decoding according to PEP 263. - -- issubclass now supports a tuple as the second argument, just like - isinstance does. ``issubclass(X, (A, B))`` is equivalent to - ``issubclass(X, A) or issubclass(X, B)``. - -- Thanks to Armin Rigo, the last known way to provoke a system crash - by cleverly arranging for a comparison function to mutate a list - during a list.sort() operation has been fixed. The effect of - attempting to mutate a list, or even to inspect its contents or - length, while a sort is in progress, is not defined by the language. - The C implementation of Python 2.3 attempts to detect mutations, - and raise ValueError if one occurs, but there's no guarantee that - all mutations will be caught, or that any will be caught across - releases or implementations. - -- Unicode file name processing for Windows (PEP 277) is implemented. - All platforms now have an os.path.supports_unicode_filenames attribute, - which is set to True on Windows NT/2000/XP, and False elsewhere. - -- Codec error handling callbacks (PEP 293) are implemented. - Error handling in unicode.encode or str.decode can now be customized. - -- A subtle change to the semantics of the built-in function intern(): - interned strings are no longer immortal. You must keep a reference - to the return value intern() around to get the benefit. - -- Use of 'None' as a variable, argument or attribute name now - issues a SyntaxWarning. In the future, None may become a keyword. - -- SET_LINENO is gone. co_lnotab is now consulted to determine when to - call the trace function. C code that accessed f_lineno should call - PyCode_Addr2Line instead (f_lineno is still there, but only kept up - to date when there is a trace function set). - -- There's a new warning category, FutureWarning. This is used to warn - about a number of situations where the value or sign of an integer - result will change in Python 2.4 as a result of PEP 237 (integer - unification). The warnings implement stage B0 mentioned in that - PEP. The warnings are about the following situations: - - - Octal and hex literals without 'L' prefix in the inclusive range - [0x80000000..0xffffffff]; these are currently negative ints, but - in Python 2.4 they will be positive longs with the same bit - pattern. - - - Left shifts on integer values that cause the outcome to lose - bits or have a different sign than the left operand. To be - precise: x<<n where this currently doesn't yield the same value - as long(x)<<n; in Python 2.4, the outcome will be long(x)<<n. - - - Conversions from ints to string that show negative values as - unsigned ints in the inclusive range [0x80000000..0xffffffff]; - this affects the functions hex() and oct(), and the string - formatting codes %u, %o, %x, and %X. In Python 2.4, these will - show signed values (e.g. hex(-1) currently returns "0xffffffff"; - in Python 2.4 it will return "-0x1"). - -- The bits manipulated under the cover by sys.setcheckinterval() have - been changed. Both the check interval and the ticker used to be - per-thread values. They are now just a pair of global variables. - In addition, the default check interval was boosted from 10 to 100 - bytecode instructions. This may have some effect on systems that - relied on the old default value. In particular, in multi-threaded - applications which try to be highly responsive, response time will - increase by some (perhaps imperceptible) amount. - -- When multiplying very large integers, a version of the so-called - Karatsuba algorithm is now used. This is most effective if the - inputs have roughly the same size. If they both have about N digits, - Karatsuba multiplication has O(N**1.58) runtime (the exponent is - log_base_2(3)) instead of the previous O(N**2). Measured results may - be better or worse than that, depending on platform quirks. Besides - the O() improvement in raw instruction count, the Karatsuba algorithm - appears to have much better cache behavior on extremely large integers - (starting in the ballpark of a million bits). Note that this is a - simple implementation, and there's no intent here to compete with, - e.g., GMP. It gives a very nice speedup when it applies, but a package - devoted to fast large-integer arithmetic should run circles around it. - -- u'%c' will now raise a ValueError in case the argument is an - integer outside the valid range of Unicode code point ordinals. - -- The tempfile module has been overhauled for enhanced security. The - mktemp() function is now deprecated; new, safe replacements are - mkstemp() (for files) and mkdtemp() (for directories), and the - higher-level functions NamedTemporaryFile() and TemporaryFile(). - Use of some global variables in this module is also deprecated; the - new functions have keyword arguments to provide the same - functionality. All Lib, Tools and Demo modules that used the unsafe - interfaces have been updated to use the safe replacements. Thanks - to Zack Weinberg! - -- When x is an object whose class implements __mul__ and __rmul__, - 1.0*x would correctly invoke __rmul__, but 1*x would erroneously - invoke __mul__. This was due to the sequence-repeat code in the int - type. This has been fixed now. - -- Previously, "str1 in str2" required str1 to be a string of length 1. - This restriction has been relaxed to allow str1 to be a string of - any length. Thus "'el' in 'hello world'" returns True now. - -- File objects are now their own iterators. For a file f, iter(f) now - returns f (unless f is closed), and f.next() is similar to - f.readline() when EOF is not reached; however, f.next() uses a - readahead buffer that messes up the file position, so mixing - f.next() and f.readline() (or other methods) doesn't work right. - Calling f.seek() drops the readahead buffer, but other operations - don't. It so happens that this gives a nice additional speed boost - to "for line in file:"; the xreadlines method and corresponding - module are now obsolete. Thanks to Oren Tirosh! - -- Encoding declarations (PEP 263, phase 1) have been implemented. A - comment of the form "# -*- coding: <encodingname> -*-" in the first - or second line of a Python source file indicates the encoding. - -- list.sort() has a new implementation. While cross-platform results - may vary, and in data-dependent ways, this is much faster on many - kinds of partially ordered lists than the previous implementation, - and reported to be just as fast on randomly ordered lists on - several major platforms. This sort is also stable (if A==B and A - precedes B in the list at the start, A precedes B after the sort too), - although the language definition does not guarantee stability. A - potential drawback is that list.sort() may require temp space of - len(list)*2 bytes (``*4`` on a 64-bit machine). It's therefore possible - for list.sort() to raise MemoryError now, even if a comparison function - does not. See <http://www.python.org/sf/587076> for full details. - -- All standard iterators now ensure that, once StopIteration has been - raised, all future calls to next() on the same iterator will also - raise StopIteration. There used to be various counterexamples to - this behavior, which could caused confusion or subtle program - breakage, without any benefits. (Note that this is still an - iterator's responsibility; the iterator framework does not enforce - this.) - -- Ctrl+C handling on Windows has been made more consistent with - other platforms. KeyboardInterrupt can now reliably be caught, - and Ctrl+C at an interactive prompt no longer terminates the - process under NT/2k/XP (it never did under Win9x). Ctrl+C will - interrupt time.sleep() in the main thread, and any child processes - created via the popen family (on win2k; we can't make win9x work - reliably) are also interrupted (as generally happens on for Linux/Unix.) - [SF bugs 231273, 439992 and 581232] - -- sys.getwindowsversion() has been added on Windows. This - returns a tuple with information about the version of Windows - currently running. - -- Slices and repetitions of buffer objects now consistently return - a string. Formerly, strings would be returned most of the time, - but a buffer object would be returned when the repetition count - was one or when the slice range was all inclusive. - -- Unicode objects in sys.path are no longer ignored but treated - as directory names. - -- Fixed string.startswith and string.endswith builtin methods - so they accept negative indices. [SF bug 493951] - -- Fixed a bug with a continue inside a try block and a yield in the - finally clause. [SF bug 567538] - -- Most builtin sequences now support "extended slices", i.e. slices - with a third "stride" parameter. For example, "hello world"[::-1] - gives "dlrow olleh". - -- A new warning PendingDeprecationWarning was added to provide - direction on features which are in the process of being deprecated. - The warning will not be printed by default. To see the pending - deprecations, use -Walways::PendingDeprecationWarning:: - as a command line option or warnings.filterwarnings() in code. - -- Deprecated features of xrange objects have been removed as - promised. The start, stop, and step attributes and the tolist() - method no longer exist. xrange repetition and slicing have been - removed. - -- New builtin function enumerate(x), from PEP 279. Example: - enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c"). - The argument can be an arbitrary iterable object. - -- The assert statement no longer tests __debug__ at runtime. This means - that assert statements cannot be disabled by assigning a false value - to __debug__. - -- A method zfill() was added to str and unicode, that fills a numeric - string to the left with zeros. For example, - "+123".zfill(6) -> "+00123". - -- Complex numbers supported divmod() and the // and % operators, but - these make no sense. Since this was documented, they're being - deprecated now. - -- String and unicode methods lstrip(), rstrip() and strip() now take - an optional argument that specifies the characters to strip. For - example, "Foo!!!?!?!?".rstrip("?!") -> "Foo". - -- There's a new dictionary constructor (a class method of the dict - class), dict.fromkeys(iterable, value=None). It constructs a - dictionary with keys taken from the iterable and all values set to a - single value. It can be used for building sets and for removing - duplicates from sequences. - -- Added a new dict method pop(key). This removes and returns the - value corresponding to key. [SF patch #539949] - -- A new built-in type, bool, has been added, as well as built-in - names for its two values, True and False. Comparisons and sundry - other operations that return a truth value have been changed to - return a bool instead. Read PEP 285 for an explanation of why this - is backward compatible. - -- Fixed two bugs reported as SF #535905: under certain conditions, - deallocating a deeply nested structure could cause a segfault in the - garbage collector, due to interaction with the "trashcan" code; - access to the current frame during destruction of a local variable - could access a pointer to freed memory. - -- The optional object allocator ("pymalloc") has been enabled by - default. The recommended practice for memory allocation and - deallocation has been streamlined. A header file is included, - Misc/pymemcompat.h, which can be bundled with 3rd party extensions - and lets them use the same API with Python versions from 1.5.2 - onwards. - -- PyErr_Display will provide file and line information for all exceptions - that have an attribute print_file_and_line, not just SyntaxErrors. - -- The UTF-8 codec will now encode and decode Unicode surrogates - correctly and without raising exceptions for unpaired ones. - -- Universal newlines (PEP 278) is implemented. Briefly, using 'U' - instead of 'r' when opening a text file for reading changes the line - ending convention so that any of '\r', '\r\n', and '\n' is - recognized (even mixed in one file); all three are converted to - '\n', the standard Python line end character. - -- file.xreadlines() now raises a ValueError if the file is closed: - Previously, an xreadlines object was returned which would raise - a ValueError when the xreadlines.next() method was called. - -- sys.exit() inadvertently allowed more than one argument. - An exception will now be raised if more than one argument is used. - -- Changed evaluation order of dictionary literals to conform to the - general left to right evaluation order rule. Now {f1(): f2()} will - evaluate f1 first. - -- Fixed bug #521782: when a file was in non-blocking mode, file.read() - could silently lose data or wrongly throw an unknown error. - -- The sq_repeat, sq_inplace_repeat, sq_concat and sq_inplace_concat - slots are now always tried after trying the corresponding nb_* slots. - This fixes a number of minor bugs (see bug #624807). - -- Fix problem with dynamic loading on 64-bit AIX (see bug #639945). - -Extension modules ------------------ - -- Added three operators to the operator module: - operator.pow(a,b) which is equivalent to: a**b. - operator.is_(a,b) which is equivalent to: a is b. - operator.is_not(a,b) which is equivalent to: a is not b. - -- posix.openpty now works on all systems that have /dev/ptmx. - -- A module zipimport exists to support importing code from zip - archives. - -- The new datetime module supplies classes for manipulating dates and - times. The basic design came from the Zope "fishbowl process", and - favors practical commercial applications over calendar esoterica. See - - http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage - -- _tkinter now returns Tcl objects, instead of strings. Objects which - have Python equivalents are converted to Python objects, other objects - are wrapped. This can be configured through the wantobjects method, - or Tkinter.wantobjects. - -- The PyBSDDB wrapper around the Sleepycat Berkeley DB library has - been added as the package bsddb. The traditional bsddb module is - still available in source code, but not built automatically anymore, - and is now named bsddb185. This supports Berkeley DB versions from - 3.0 to 4.1. For help converting your databases from the old module (which - probably used an obsolete version of Berkeley DB) to the new module, see - the db2pickle.py and pickle2db.py scripts described in the Tools/Demos - section above. - -- unicodedata was updated to Unicode 3.2. It supports normalization - and names for Hangul syllables and CJK unified ideographs. - -- resource.getrlimit() now returns longs instead of ints. - -- readline now dynamically adjusts its input/output stream if - sys.stdin/stdout changes. - -- The _tkinter module (and hence Tkinter) has dropped support for - Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are - supported. - -- cPickle.BadPickleGet is now a class. - -- The time stamps in os.stat_result are floating point numbers - after stat_float_times has been called. - -- If the size passed to mmap.mmap() is larger than the length of the - file on non-Windows platforms, a ValueError is raised. [SF bug 585792] - -- The xreadlines module is slated for obsolescence. - -- The strptime function in the time module is now always available (a - Python implementation is used when the C library doesn't define it). - -- The 'new' module is no longer an extension, but a Python module that - only exists for backwards compatibility. Its contents are no longer - functions but callable type objects. - -- The bsddb.*open functions can now take 'None' as a filename. - This will create a temporary in-memory bsddb that won't be - written to disk. - -- posix.getloadavg, posix.lchown, posix.killpg, posix.mknod, and - posix.getpgid have been added where available. - -- The locale module now exposes the C library's gettext interface. It - also has a new function getpreferredencoding. - -- A security hole ("double free") was found in zlib-1.1.3, a popular - third party compression library used by some Python modules. The - hole was quickly plugged in zlib-1.1.4, and the Windows build of - Python now ships with zlib-1.1.4. - -- pwd, grp, and resource return enhanced tuples now, with symbolic - field names. - -- array.array is now a type object. A new format character - 'u' indicates Py_UNICODE arrays. For those, .tounicode and - .fromunicode methods are available. Arrays now support __iadd__ - and __imul__. - -- dl now builds on every system that has dlfcn.h. Failure in case - of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open - is called. - -- The sys module acquired a new attribute, api_version, which evaluates - to the value of the PYTHON_API_VERSION macro with which the - interpreter was compiled. - -- Fixed bug #470582: sre module would return a tuple (None, 'a', 'ab') - when applying the regular expression '^((a)c)?(ab)$' on 'ab'. It now - returns (None, None, 'ab'), as expected. Also fixed handling of - lastindex/lastgroup match attributes in similar cases. For example, - when running the expression r'(a)(b)?b' over 'ab', lastindex must be - 1, not 2. - -- Fixed bug #581080: sre scanner was not checking the buffer limit - before increasing the current pointer. This was creating an infinite - loop in the search function, once the pointer exceeded the buffer - limit. - -- The os.fdopen function now enforces a file mode starting with the - letter 'r', 'w' or 'a', otherwise a ValueError is raised. This fixes - bug #623464. - -- The linuxaudiodev module is now deprecated; it is being replaced by - ossaudiodev. The interface has been extended to cover a lot more of - OSS (see www.opensound.com), including most DSP ioctls and the - OSS mixer API. Documentation forthcoming in 2.3a2. - -Library -------- - -- imaplib.py now supports SSL (Tino Lange and Piers Lauder). - -- Freeze's modulefinder.py has been moved to the standard library; - slightly improved so it will issue less false missing submodule - reports (see sf path #643711 for details). Documentation will follow - with Python 2.3a2. - -- os.path exposes getctime. - -- unittest.py now has two additional methods called assertAlmostEqual() - and failIfAlmostEqual(). They implement an approximate comparison - by rounding the difference between the two arguments and comparing - the result to zero. Approximate comparison is essential for - unit tests of floating point results. - -- calendar.py now depends on the new datetime module rather than - the time module. As a result, the range of allowable dates - has been increased. - -- pdb has a new 'j(ump)' command to select the next line to be - executed. - -- The distutils created windows installers now can run a - postinstallation script. - -- doctest.testmod can now be called without argument, which means to - test the current module. - -- When canceling a server that implemented threading with a keyboard - interrupt, the server would shut down but not terminate (waiting on - client threads). A new member variable, daemon_threads, was added to - the ThreadingMixIn class in SocketServer.py to make it explicit that - this behavior needs to be controlled. - -- A new module, optparse, provides a fancy alternative to getopt for - command line parsing. It is a slightly modified version of Greg - Ward's Optik package. - -- UserDict.py now defines a DictMixin class which defines all dictionary - methods for classes that already have a minimum mapping interface. - This greatly simplifies writing classes that need to be substitutable - for dictionaries (such as the shelve module). - -- shelve.py now subclasses from UserDict.DictMixin. Now shelve supports - all dictionary methods. This eases the transition to persistent - storage for scripts originally written with dictionaries in mind. - -- shelve.open and the various classes in shelve.py now accept an optional - binary flag, which defaults to False. If True, the values stored in the - shelf are binary pickles. - -- A new package, logging, implements the logging API defined by PEP - 282. The code is written by Vinay Sajip. - -- StreamReader, StreamReaderWriter and StreamRecoder in the codecs - modules are iterators now. - -- gzip.py now handles files exceeding 2GB. Files over 4GB also work - now (provided the OS supports it, and Python is configured with large - file support), but in that case the underlying gzip file format can - record only the least-significant 32 bits of the file size, so that - some tools working with gzipped files may report an incorrect file - size. - -- xml.sax.saxutils.unescape has been added, to replace entity references - with their entity value. - -- Queue.Queue.{put,get} now support an optional timeout argument. - -- Various features of Tk 8.4 are exposed in Tkinter.py. The multiple - option of tkFileDialog is exposed as function askopenfile{,name}s. - -- Various configure methods of Tkinter have been stream-lined, so that - tag_configure, image_configure, window_configure now return a - dictionary when invoked with no argument. - -- Importing the readline module now no longer has the side effect of - calling setlocale(LC_CTYPE, ""). The initial "C" locale, or - whatever locale is explicitly set by the user, is preserved. If you - want repr() of 8-bit strings in your preferred encoding to preserve - all printable characters of that encoding, you have to add the - following code to your $PYTHONSTARTUP file or to your application's - main(): - - import locale - locale.setlocale(locale.LC_CTYPE, "") - -- shutil.move was added. shutil.copytree now reports errors as an - exception at the end, instead of printing error messages. - -- Encoding name normalization was generalized to not only - replace hyphens with underscores, but also all other non-alphanumeric - characters (with the exception of the dot which is used for Python - package names during lookup). The aliases.py mapping was updated - to the new standard. - -- mimetypes has two new functions: guess_all_extensions() which - returns a list of all known extensions for a mime type, and - add_type() which adds one mapping between a mime type and - an extension to the database. - -- New module: sets, defines the class Set that implements a mutable - set type using the keys of a dict to represent the set. There's - also a class ImmutableSet which is useful when you need sets of sets - or when you need to use sets as dict keys, and a class BaseSet which - is the base class of the two. - -- Added random.sample(population,k) for random sampling without replacement. - Returns a k length list of unique elements chosen from the population. - -- random.randrange(-sys.maxint-1, sys.maxint) no longer raises - OverflowError. That is, it now accepts any combination of 'start' - and 'stop' arguments so long as each is in the range of Python's - bounded integers. - -- Thanks to Raymond Hettinger, random.random() now uses a new core - generator. The Mersenne Twister algorithm is implemented in C, - threadsafe, faster than the previous generator, has an astronomically - large period (2**19937-1), creates random floats to full 53-bit - precision, and may be the most widely tested random number generator - in existence. - - The random.jumpahead(n) method has different semantics for the new - generator. Instead of jumping n steps ahead, it uses n and the - existing state to create a new state. This means that jumpahead() - continues to support multi-threaded code needing generators of - non-overlapping sequences. However, it will break code which relies - on jumpahead moving a specific number of steps forward. - - The attributes random.whseed and random.__whseed have no meaning for - the new generator. Code using these attributes should switch to a - new class, random.WichmannHill which is provided for backward - compatibility and to make an alternate generator available. - -- New "algorithms" module: heapq, implements a heap queue. Thanks to - Kevin O'Connor for the code and François Pinard for an entertaining - write-up explaining the theory and practical uses of heaps. - -- New encoding for the Palm OS character set: palmos. - -- binascii.crc32() and the zipfile module had problems on some 64-bit - platforms. These have been fixed. On a platform with 8-byte C longs, - crc32() now returns a signed-extended 4-byte result, so that its value - as a Python int is equal to the value computed a 32-bit platform. - -- xml.dom.minidom.toxml and toprettyxml now take an optional encoding - argument. - -- Some fixes in the copy module: when an object is copied through its - __reduce__ method, there was no check for a __setstate__ method on - the result [SF patch 565085]; deepcopy should treat instances of - custom metaclasses the same way it treats instances of type 'type' - [SF patch 560794]. - -- Sockets now support timeout mode. After s.settimeout(T), where T is - a float expressing seconds, subsequent operations raise an exception - if they cannot be completed within T seconds. To disable timeout - mode, use s.settimeout(None). There's also a module function, - socket.setdefaulttimeout(T), which sets the default for all sockets - created henceforth. - -- getopt.gnu_getopt was added. This supports GNU-style option - processing, where options can be mixed with non-option arguments. - -- Stop using strings for exceptions. String objects used for - exceptions are now classes deriving from Exception. The objects - changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error, - tabnanny.NannyNag, and xdrlib.Error. - -- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE, - BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte - Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and - big endian systems were added to the codecs module. The old names - BOM32_* and BOM64_* were off by a factor of 2. - -- Added conversion functions math.degrees() and math.radians(). - -- math.log() now takes an optional argument: math.log(x[, base]). - -- ftplib.retrlines() now tests for callback is None rather than testing - for False. Was causing an error when given a callback object which - was callable but also returned len() as zero. The change may - create new breakage if the caller relied on the undocumented behavior - and called with callback set to [] or some other False value not - identical to None. - -- random.gauss() uses a piece of hidden state used by nothing else, - and the .seed() and .whseed() methods failed to reset it. In other - words, setting the seed didn't completely determine the sequence of - results produced by random.gauss(). It does now. Programs repeatedly - mixing calls to a seed method with calls to gauss() may see different - results now. - -- The pickle.Pickler class grew a clear_memo() method to mimic that - provided by cPickle.Pickler. - -- difflib's SequenceMatcher class now does a dynamic analysis of - which elements are so frequent as to constitute noise. For - comparing files as sequences of lines, this generally works better - than the IS_LINE_JUNK function, and function ndiff's linejunk - argument defaults to None now as a result. A happy benefit is - that SequenceMatcher may run much faster now when applied - to large files with many duplicate lines (for example, C program - text with lots of repeated "}" and "return NULL;" lines). - -- New Text.dump() method in Tkinter module. - -- New distutils commands for building packagers were added to - support pkgtool on Solaris and swinstall on HP-UX. - -- distutils now has a new abstract binary packager base class - command/bdist_packager, which simplifies writing packagers. - This will hopefully provide the missing bits to encourage - people to submit more packagers, e.g. for Debian, FreeBSD - and other systems. - -- The UTF-16, -LE and -BE stream readers now raise a - NotImplementedError for all calls to .readline(). Previously, they - used to just produce garbage or fail with an encoding error -- - UTF-16 is a 2-byte encoding and the C lib's line reading APIs don't - work well with these. - -- compileall now supports quiet operation. - -- The BaseHTTPServer now implements optional HTTP/1.1 persistent - connections. - -- socket module: the SSL support was broken out of the main - _socket module C helper and placed into a new _ssl helper - which now gets imported by socket.py if available and working. - -- encodings package: added aliases for all supported IANA character - sets - -- ftplib: to safeguard the user's privacy, anonymous login will use - "anonymous@" as default password, rather than the real user and host - name. - -- webbrowser: tightened up the command passed to os.system() so that - arbitrary shell code can't be executed because a bogus URL was - passed in. - -- gettext.translation has an optional fallback argument, and - gettext.find an optional all argument. Translations will now fallback - on a per-message basis. The module supports plural forms, by means - of gettext.[d]ngettext and Translation.[u]ngettext. - -- distutils bdist commands now offer a --skip-build option. - -- warnings.warn now accepts a Warning instance as first argument. - -- The xml.sax.expatreader.ExpatParser class will no longer create - circular references by using itself as the locator that gets passed - to the content handler implementation. [SF bug #535474] - -- The email.Parser.Parser class now properly parses strings regardless - of their line endings, which can be any of \r, \n, or \r\n (CR, LF, - or CRLF). Also, the Header class's constructor default arguments - has changed slightly so that an explicit maxlinelen value is always - honored, and so unicode conversion error handling can be specified. - -- distutils' build_ext command now links C++ extensions with the C++ - compiler available in the Makefile or CXX environment variable, if - running under \*nix. - -- New module bz2: provides a comprehensive interface for the bz2 compression - library. It implements a complete file interface, one-shot (de)compression - functions, and types for sequential (de)compression. - -- New pdb command 'pp' which is like 'p' except that it pretty-prints - the value of its expression argument. - -- Now bdist_rpm distutils command understands a verify_script option in - the config file, including the contents of the referred filename in - the "%verifyscript" section of the rpm spec file. - -- Fixed bug #495695: webbrowser module would run graphic browsers in a - unix environment even if DISPLAY was not set. Also, support for - skipstone browser was included. - -- Fixed bug #636769: rexec would run unallowed code if subclasses of - strings were used as parameters for certain functions. - -Tools/Demos ------------ - -- pygettext.py now supports globbing on Windows, and accepts module - names in addition to accepting file names. - -- The SGI demos (Demo/sgi) have been removed. Nobody thought they - were interesting any more. (The SGI library modules and extensions - are still there; it is believed that at least some of these are - still used and useful.) - -- IDLE supports the new encoding declarations (PEP 263); it can also - deal with legacy 8-bit files if they use the locale's encoding. It - allows non-ASCII strings in the interactive shell and executes them - in the locale's encoding. - -- freeze.py now produces binaries which can import shared modules, - unlike before when this failed due to missing symbol exports in - the generated binary. - -Build ------ - -- On Unix, IDLE is now installed automatically. - -- The fpectl module is not built by default; it's dangerous or useless - except in the hands of experts. - -- The public Python C API will generally be declared using PyAPI_FUNC - and PyAPI_DATA macros, while Python extension module init functions - will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros - are deprecated. - -- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or - get into infinite loops, when a new-style class got garbage-collected. - Unfortunately, to avoid this, the way COUNT_ALLOCS works requires - that new-style classes be immortal in COUNT_ALLOCS builds. Note that - COUNT_ALLOCS is not enabled by default, in either release or debug - builds, and that new-style classes are immortal only in COUNT_ALLOCS - builds. - -- Compiling out the cyclic garbage collector is no longer an option. - The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges - that it's always defined (for the benefit of any extension modules - that may be conditionalizing on it). A bonus is that any extension - type participating in cyclic gc can choose to participate in the - Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used - to require editing the core to teach the trashcan mechanism about the - new type. - -- According to Annex F of the current C standard, - - The Standard C macro HUGE_VAL and its float and long double analogs, - HUGE_VALF and HUGE_VALL, expand to expressions whose values are - positive infinities. - - Python only uses the double HUGE_VAL, and only to #define its own symbol - Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL. - pyport.h used to try to worm around that, but the workarounds triggered - other bugs on other platforms, so we gave up. If your platform defines - HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something - that works on your platform. The only instance of this I'm sure about - is on an unknown subset of Cray systems, described here: - - http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm - - Presumably 2.3a1 breaks such systems. If anyone uses such a system, help! - -- The configure option --without-doc-strings can be used to remove the - doc strings from the builtin functions and modules; this reduces the - size of the executable. - -- The universal newlines option (PEP 278) is on by default. On Unix - it can be disabled by passing --without-universal-newlines to the - configure script. On other platforms, remove - WITH_UNIVERSAL_NEWLINES from pyconfig.h. - -- On Unix, a shared libpython2.3.so can be created with --enable-shared. - -- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS - preprocessor symbols were eliminated. The internal decisions they - controlled stopped being experimental long ago. - -- The tools used to build the documentation now work under Cygwin as - well as Unix. - -- The bsddb and dbm module builds have been changed to try and avoid version - skew problems and disable linkage with Berkeley DB 1.85 unless the - installer knows what s/he's doing. See the section on building these - modules in the README file for details. - -C API ------ - -- PyNumber_Check() now returns true for string and unicode objects. - This is a result of these types having a partially defined - tp_as_number slot. (This is not a feature, but an indication that - PyNumber_Check() is not very useful to determine numeric behavior. - It may be deprecated.) - -- The string object's layout has changed: the pointer member - ob_sinterned has been replaced by an int member ob_sstate. On some - platforms (e.g. most 64-bit systems) this may change the offset of - the ob_sval member, so as a precaution the API_VERSION has been - incremented. The apparently unused feature of "indirect interned - strings", supported by the ob_sinterned member, is gone. Interned - strings are now usually mortal; there is a new API, - PyString_InternImmortal() that creates immortal interned strings. - (The ob_sstate member can only take three values; however, while - making it a char saves a few bytes per string object on average, in - it also slowed things down a bit because ob_sval was no longer - aligned.) - -- The Py_InitModule*() functions now accept NULL for the 'methods' - argument. Modules without global functions are becoming more common - now that factories can be types rather than functions. - -- New C API PyUnicode_FromOrdinal() which exposes unichr() at C - level. - -- New functions PyErr_SetExcFromWindowsErr() and - PyErr_SetExcFromWindowsErrWithFilename(). Similar to - PyErr_SetFromWindowsErrWithFilename() and - PyErr_SetFromWindowsErr(), but they allow to specify - the exception type to raise. Available on Windows. - -- Py_FatalError() is now declared as taking a const char* argument. It - was previously declared without const. This should not affect working - code. - -- Added new macro PySequence_ITEM(o, i) that directly calls - sq_item without rechecking that o is a sequence and without - adjusting for negative indices. - -- PyRange_New() now raises ValueError if the fourth argument is not 1. - This is part of the removal of deprecated features of the xrange - object. - -- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's - coercion if both arguments have the same type but this type has the - CHECKTYPES flag set. This is to better support proxies. - -- The type of tp_free has been changed from "``void (*)(PyObject *)``" to - "``void (*)(void *)``". - -- PyObject_Del, PyObject_GC_Del are now functions instead of macros. - -- A type can now inherit its metatype from its base type. Previously, - when PyType_Ready() was called, if ob_type was found to be NULL, it - was always set to &PyType_Type; now it is set to base->ob_type, - where base is tp_base, defaulting to &PyObject_Type. - -- PyType_Ready() accidentally did not inherit tp_is_gc; now it does. - -- The PyCore_* family of APIs have been removed. - -- The "u#" parser marker will now pass through Unicode objects as-is - without going through the buffer API. - -- The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``. - -- An old #define of ANY as void has been removed from pyport.h. This - hasn't been used since Python's pre-ANSI days, and the #define has - been marked as obsolete since then. SF bug 495548 says it created - conflicts with other packages, so keeping it around wasn't harmless. - -- Because Python's magic number scheme broke on January 1st, we decided - to stop Python development. Thanks for all the fish! - -- Some of us don't like fish, so we changed Python's magic number - scheme to a new one. See Python/import.c for details. - -New platforms -------------- - -- OpenVMS is now supported. - -- AtheOS is now supported. - -- the EMX runtime environment on OS/2 is now supported. - -- GNU/Hurd is now supported. - -Tests ------ - -- The regrtest.py script's -u option now provides a way to say "allow - all resources except this one." For example, to allow everything - except bsddb, give the option '-uall,-bsddb'. - -Windows -------- - -- The Windows distribution now ships with version 4.0.14 of the - Sleepycat Berkeley database library. This should be a huge - improvement over the previous Berkeley DB 1.85, which had many - bugs. - XXX What are the licensing issues here? - XXX If a user has a database created with a previous version of - XXX Python, what must they do to convert it? - XXX I'm still not sure how to link this thing (see PCbuild/readme.txt). - XXX The version # is likely to change before 2.3a1. - -- The Windows distribution now ships with a Secure Sockets Library (SLL) - module (_ssl.pyd) - -- The Windows distribution now ships with Tcl/Tk version 8.4.1 (it - previously shipped with Tcl/Tk 8.3.2). - -- When Python is built under a Microsoft compiler, sys.version now - includes the compiler version number (_MSC_VER). For example, under - MSVC 6, sys.version contains the substring "MSC v.1200 ". 1200 is - the value of _MSC_VER under MSVC 6. - -- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause - of that has been fixed in the installer (disabled Wise's "delete in- - use files" uninstall option). - -- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031] - -- The installer now installs Start menu shortcuts under (the local - equivalent of) "All Users" when doing an Admin install. - -- file.truncate([newsize]) now works on Windows for all newsize values. - It used to fail if newsize didn't fit in 32 bits, reflecting a - limitation of MS _chsize (which is no longer used). - -- os.waitpid() is now implemented for Windows, and can be used to block - until a specified process exits. This is similar to, but not exactly - the same as, os.waitpid() on POSIX systems. If you're waiting for - a specific process whose pid was obtained from one of the spawn() - functions, the same Python os.waitpid() code works across platforms. - See the docs for details. The docs were changed to clarify that - spawn functions return, and waitpid requires, a process handle on - Windows (not the same thing as a Windows process id). - -- New tempfile.TemporaryFile implementation for Windows: this doesn't - need a TemporaryFileWrapper wrapper anymore, and should be immune - to a nasty problem: before 2.3, if you got a temp file on Windows, it - got wrapped in an object whose close() method first closed the - underlying file, then deleted the file. This usually worked fine. - However, the spawn family of functions on Windows create (at a low C - level) the same set of open files in the spawned process Q as were - open in the spawning process P. If a temp file f was among them, then - doing f.close() in P first closed P's C-level file handle on f, but Q's - C-level file handle on f remained open, so the attempt in P to delete f - blew up with a "Permission denied" error (Windows doesn't allow - deleting open files). This was surprising, subtle, and difficult to - work around. - -- The os module now exports all the symbolic constants usable with the - low-level os.open() on Windows: the new constants in 2.3 are - O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL. - The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT, - O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary - to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY - (so specify both if you want both; note that neither is useful unless - specified with O_CREAT too). - -Mac ----- - -- Mac/Relnotes is gone, the release notes are now here. - -- Python (the OSX-only, unix-based version, not the OS9-compatible CFM - version) now fully supports unicode strings as arguments to various file - system calls, eg. open(), file(), os.stat() and os.listdir(). - -- The current naming convention for Python on the Macintosh is that MacPython - refers to the unix-based OSX-only version, and MacPython-OS9 refers to the - CFM-based version that runs on both OS9 and OSX. - -- All MacPython-OS9 functionality is now available in an OSX unix build, - including the Carbon modules, the IDE, OSA support, etc. A lot of this - will only work correctly in a framework build, though, because you cannot - talk to the window manager unless your application is run from a .app - bundle. There is a command line tool "pythonw" that runs your script - with an interpreter living in such a .app bundle, this interpreter should - be used to run any Python script using the window manager (including - Tkinter or wxPython scripts). - -- Most of Mac/Lib has moved to Lib/plat-mac, which is again used both in - MacPython-OSX and MacPython-OS9. The only modules remaining in Mac/Lib - are specifically for MacPython-OS9 (CFM support, preference resources, etc). - -- A new utility PythonLauncher will start a Python interpreter when a .py or - .pyw script is double-clicked in the Finder. By default .py scripts are - run with a normal Python interpreter in a Terminal window and .pyw - files are run with a window-aware pythonw interpreter without a Terminal - window, but all this can be customized. - -- MacPython-OS9 is now Carbon-only, so it runs on Mac OS 9 or Mac OS X and - possibly on Mac OS 8.6 with the right CarbonLib installed, but not on earlier - releases. - -- Many tools such as BuildApplet.py and gensuitemodule.py now support a command - line interface too. - -- All the Carbon classes are now PEP253 compliant, meaning that you can - subclass them from Python. Most of the attributes have gone, you should - now use the accessor function call API, which is also what Apple's - documentation uses. Some attributes such as grafport.visRgn are still - available for convenience. - -- New Carbon modules File (implementing the APIs in Files.h and Aliases.h) - and Folder (APIs from Folders.h). The old macfs builtin module is - gone, and replaced by a Python wrapper around the new modules. - -- Pathname handling should now be fully consistent: MacPython-OSX always uses - unix pathnames and MacPython-OS9 always uses colon-separated Mac pathnames - (also when running on Mac OS X). - -- New Carbon modules Help and AH give access to the Carbon Help Manager. - There are hooks in the IDE to allow accessing the Python documentation - (and Apple's Carbon and Cocoa documentation) through the Help Viewer. - See Mac/OSX/README for converting the Python documentation to a - Help Viewer compatible form and installing it. - -- OSA support has been redesigned and the generated Python classes now - mirror the inheritance defined by the underlying OSA classes. - -- MacPython no longer maps both \r and \n to \n on input for any text file. - This feature has been replaced by universal newline support (PEP278). - -- The default encoding for Python sourcefiles in MacPython-OS9 is no longer - mac-roman (or whatever your local Mac encoding was) but "ascii", like on - other platforms. If you really need sourcefiles with Mac characters in them - you can change this in site.py. - - -What's New in Python 2.2 final? -=============================== - -*Release date: 21-Dec-2001* - -Type/class unification and new-style classes --------------------------------------------- - -- pickle.py, cPickle: allow pickling instances of new-style classes - with a custom metaclass. - -Core and builtins ------------------ - -- weakref proxy object: when comparing, unwrap both arguments if both - are proxies. - -Extension modules ------------------ - -- binascii.b2a_base64(): fix a potential buffer overrun when encoding - very short strings. - -- cPickle: the obscure "fast" mode was suspected of causing stack - overflows on the Mac. Hopefully fixed this by setting the recursion - limit much smaller. If the limit is too low (it only affects - performance), you can change it by defining PY_CPICKLE_FAST_LIMIT - when compiling cPickle.c (or in pyconfig.h). - -Library -------- - -- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at - close or delete time). - -- rfc822.py: fixed a bug where the address '<>' was converted to None - instead of an empty string (also fixes the email.Utils module). - -- xmlrpclib.py: version 1.0.0; uses precision for doubles. - -- test suite: the pickle and cPickle tests were not executing any code - when run from the standard regression test. - -Tools/Demos ------------ - -Build ------ - -C API ------ - -New platforms -------------- - -Tests ------ - -Windows -------- - -- distutils package: fixed broken Windows installers (bdist_wininst). - -- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper - instances are deleted at process exit time. - -- socket.py: prevent mysterious warnings when socket instances are - deleted at process exit time. - -- posixmodule.c: fix a Windows crash with stat() of a filename ending - in backslash. - -Mac ----- - -- The Carbon toolbox modules have been upgraded to Universal Headers - 3.4, and experimental CoreGraphics and CarbonEvents modules have - been added. All only for framework-enabled MacOSX. - - -What's New in Python 2.2c1? -=========================== - -*Release date: 14-Dec-2001* - -Type/class unification and new-style classes --------------------------------------------- - -- Guido's tutorial introduction to the new type/class features has - been extensively updated. See - - http://www.python.org/2.2/descrintro.html - - That remains the primary documentation in this area. - -- Fixed a leak: instance variables declared with __slots__ were never - deleted! - -- The "delete attribute" method of descriptor objects is called - __delete__, not __del__. In previous releases, it was mistakenly - called __del__, which created an unfortunate overloading condition - with finalizers. (The "get attribute" and "set attribute" methods - are still called __get__ and __set__, respectively.) - -- Some subtle issues with the super built-in were fixed: - - (a) When super itself is subclassed, its __get__ method would still - return an instance of the base class (i.e., of super). - - (b) super(C, C()).__class__ would return C rather than super. This - is confusing. To fix this, I decided to change the semantics of - super so that it only applies to code attributes, not to data - attributes. After all, overriding data attributes is not - supported anyway. - - (c) The __get__ method didn't check whether the argument was an - instance of the type used in creation of the super instance. - -- Previously, hash() of an instance of a subclass of a mutable type - (list or dictionary) would return some value, rather than raising - TypeError. This has been fixed. Also, directly calling - dict.__hash__ and list.__hash__ now raises the same TypeError - (previously, these were the same as object.__hash__). - -- New-style objects now support deleting their __dict__. This is for - all intents and purposes equivalent to assigning a brand new empty - dictionary, but saves space if the object is not used further. - -Core and builtins ------------------ - -- -Qnew now works as documented in PEP 238: when -Qnew is passed on - the command line, all occurrences of "/" use true division instead - of classic division. See the PEP for details. Note that "all" - means all instances in library and 3rd-party modules, as well as in - your own code. As the PEP says, -Qnew is intended for use only in - educational environments with control over the libraries in use. - Note that test_coercion.py in the standard Python test suite fails - under -Qnew; this is expected, and won't be repaired until true - division becomes the default (in the meantime, test_coercion is - testing the current rules). - -- complex() now only allows the first argument to be a string - argument, and raises TypeError if either the second arg is a string - or if the second arg is specified when the first is a string. - -Extension modules ------------------ - -- gc.get_referents was renamed to gc.get_referrers. - -Library -------- - -- Functions in the os.spawn() family now release the global interpreter - lock around calling the platform spawn. They should always have done - this, but did not before 2.2c1. Multithreaded programs calling - an os.spawn function with P_WAIT will no longer block all Python threads - until the spawned program completes. It's possible that some programs - relies on blocking, although more likely by accident than by design. - -- webbrowser defaults to netscape.exe on OS/2 now. - -- Tix.ResizeHandle exposes detach_widget, hide, and show. - -- The charset alias windows_1252 has been added. - -- types.StringTypes is a tuple containing the defined string types; - usually this will be (str, unicode), but if Python was compiled - without Unicode support it will be just (str,). - -- The pulldom and minidom modules were synchronized to PyXML. - -Tools/Demos ------------ - -- A new script called Tools/scripts/google.py was added, which fires - off a search on Google. - -Build ------ - -- Note that release builds of Python should arrange to define the - preprocessor symbol NDEBUG on the command line (or equivalent). - In the 2.2 pre-release series we tried to define this by magic in - Python.h instead, but it proved to cause problems for extension - authors. The Unix, Windows and Mac builds now all define NDEBUG in - release builds via cmdline (or equivalent) instead. Ports to - other platforms should do likewise. - -- It is no longer necessary to use --with-suffix when building on a - case-insensitive file system (such as Mac OS X HFS+). In the build - directory an extension is used, but not in the installed python. - -C API ------ - -- New function PyDict_MergeFromSeq2() exposes the builtin dict - constructor's logic for updating a dictionary from an iterable object - producing key-value pairs. - -- PyArg_ParseTupleAndKeywords() requires that the number of entries in - the keyword list equal the number of argument specifiers. This - wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even - dump core in some bad cases. This has been repaired. As a result, - PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that - previously went unchallenged. - -New platforms -------------- - -Tests ------ - -Windows -------- - -Mac ----- - -- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin", - without any trailing digits. - -- Changed logic for finding python home in Mac OS X framework Pythons. - Now sys.executable points to the executable again, in stead of to - the shared library. The latter is used only for locating the python - home. - - -What's New in Python 2.2b2? -=========================== - -*Release date: 16-Nov-2001* - -Type/class unification and new-style classes --------------------------------------------- - -- Multiple inheritance mixing new-style and classic classes in the - list of base classes is now allowed, so this works now: - - class Classic: pass - class Mixed(Classic, object): pass - - The MRO (method resolution order) for each base class is respected - according to its kind, but the MRO for the derived class is computed - using new-style MRO rules if any base class is a new-style class. - This needs to be documented. - -- The new builtin dictionary() constructor, and dictionary type, have - been renamed to dict. This reflects a decade of common usage. - -- dict() now accepts an iterable object producing 2-sequences. For - example, dict(d.items()) == d for any dictionary d. The argument, - and the elements of the argument, can be any iterable objects. - -- New-style classes can now have a __del__ method, which is called - when the instance is deleted (just like for classic classes). - -- Assignment to object.__dict__ is now possible, for objects that are - instances of new-style classes that have a __dict__ (unless the base - class forbids it). - -- Methods of built-in types now properly check for keyword arguments - (formerly these were silently ignored). The only built-in methods - that take keyword arguments are __call__, __init__ and __new__. - -- The socket function has been converted to a type; see below. - -Core and builtins ------------------ - -- Assignment to __debug__ raises SyntaxError at compile-time. This - was promised when 2.1c1 was released as "What's New in Python 2.1c1" - (see below) says. - -- Clarified the error messages for unsupported operands to an operator - (like 1 + ''). - -Extension modules ------------------ - -- mmap has a new keyword argument, "access", allowing a uniform way for - both Windows and Unix users to create read-only, write-through and - copy-on-write memory mappings. This was previously possible only on - Unix. A new keyword argument was required to support this in a - uniform way because the mmap() signatures had diverged across - platforms. Thanks to Jay T Miller for repairing this! - -- By default, the gc.garbage list now contains only those instances in - unreachable cycles that have __del__ methods; in 2.1 it contained all - instances in unreachable cycles. "Instances" here has been generalized - to include instances of both new-style and old-style classes. - -- The socket module defines a new method for socket objects, - sendall(). This is like send() but may make multiple calls to - send() until all data has been sent. Also, the socket function has - been converted to a subclassable type, like list and tuple (etc.) - before it; socket and SocketType are now the same thing. - -- Various bugfixes to the curses module. There is now a test suite - for the curses module (you have to run it manually). - -- binascii.b2a_base64 no longer places an arbitrary restriction of 57 - bytes on its input. - -Library -------- - -- tkFileDialog exposes a Directory class and askdirectory - convenience function. - -- Symbolic group names in regular expressions must be unique. For - example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a - single name can't mean both "group 1" and "group 2" simultaneously. - Python 2.2 detects this error at regexp compilation time; - previously, the error went undetected, and results were - unpredictable. Also in sre, the pattern.split(), pattern.sub(), and - pattern.subn() methods have been rewritten in C. Also, an - experimental function/method finditer() has been added, which works - like findall() but returns an iterator. - -- Tix exposes more commands through the classes DirSelectBox, - DirSelectDialog, ListNoteBook, Meter, CheckList, and the - methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog, - tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions. - -- Traceback objects are now scanned by cyclic garbage collection, so - cycles created by casual use of sys.exc_info() no longer cause - permanent memory leaks (provided garbage collection is enabled). - -- os.extsep -- a new variable needed by the RISCOS support. It is the - separator used by extensions, and is '.' on all platforms except - RISCOS, where it is '/'. There is no need to use this variable - unless you have a masochistic desire to port your code to RISCOS. - -- mimetypes.py has optional support for non-standard, but commonly - found types. guess_type() and guess_extension() now accept an - optional 'strict' flag, defaulting to true, which controls whether - recognize non-standard types or not. A few non-standard types we - know about have been added. Also, when run as a script, there are - new -l and -e options. - -- statcache is now deprecated. - -- email.Utils.formatdate() now produces the preferred RFC 2822 style - dates with numeric timezones (it used to produce obsolete dates - hard coded to "GMT" timezone). An optional 'localtime' flag is - added to produce dates in the local timezone, with daylight savings - time properly taken into account. - -- In pickle and cPickle, instead of masking errors in load() by - transforming them into SystemError, we let the original exception - propagate out. Also, implement support for __safe_for_unpickling__ - in pickle, as it already was supported in cPickle. - -Tools/Demos ------------ - -Build ------ - -- The dbm module is built using libdb1 if available. The bsddb module - is built with libdb3 if available. - -- Misc/Makefile.pre.in has been removed by BDFL pronouncement. - -C API ------ - -- New function PySequence_Fast_GET_SIZE() returns the size of a non- - NULL result from PySequence_Fast(), more quickly than calling - PySequence_Size(). - -- New argument unpacking function PyArg_UnpackTuple() added. - -- New functions PyObject_CallFunctionObjArgs() and - PyObject_CallMethodObjArgs() have been added to make it more - convenient and efficient to call functions and methods from C. - -- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's - possible that this will propagate errors it didn't before. - -- New function PyObject_CheckReadBuffer(), which returns true if its - argument supports the single-segment readable buffer interface. - New platforms ------------- -- We've finally confirmed that this release builds on HP-UX 11.00, - *with* threads, and passes the test suite. - -- Thanks to a series of patches from Michael Muller, Python may build - again under OS/2 Visual Age C++. - -- Updated RISCOS port by Dietmar Schwertberger. - -Tests ------ - -- Added a test script for the curses module. It isn't run automatically; - regrtest.py must be run with '-u curses' to enable it. - -Windows -------- - -Mac ----- - -- PythonScript has been moved to unsupported and is slated to be - removed completely in the next release. - -- It should now be possible to build applets that work on both OS9 and - OSX. - -- The core is now linked with CoreServices not Carbon; as a side - result, default 8bit encoding on OSX is now ASCII. - -- Python should now build on OSX 10.1.1 - - -What's New in Python 2.2b1? -=========================== - -*Release date: 19-Oct-2001* - -Type/class unification and new-style classes --------------------------------------------- - -- New-style classes are now always dynamic (except for built-in and - extension types). There is no longer a performance penalty, and I - no longer see another reason to keep this baggage around. One relic - remains: the __dict__ of a new-style class is a read-only proxy; you - must set the class's attribute to modify it. As a consequence, the - __defined__ attribute of new-style types no longer exists, for lack - of need: there is once again only one __dict__ (although in the - future a __cache__ may be resurrected with a similar function, if I - can prove that it actually speeds things up). - -- C.__doc__ now works as expected for new-style classes (in 2.2a4 it - always returned None, even when there was a class docstring). - -- doctest now finds and runs docstrings attached to new-style classes, - class methods, static methods, and properties. - -Core and builtins ------------------ - -- A very subtle syntactical pitfall in list comprehensions was fixed. - For example: [a+b for a in 'abc', for b in 'def']. The comma in - this example is a mistake. Previously, this would silently let 'a' - iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce', - 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be', - 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error. - Note that [a for a in <singleton>] is a convoluted way to say - [<singleton>] anyway, so it's not like any expressiveness is lost. - -- getattr(obj, name, default) now only catches AttributeError, as - documented, rather than returning the default value for all - exceptions (which could mask bugs in a __getattr__ hook, for - example). - -- Weak reference objects are now part of the core and offer a C API. - A bug which could allow a core dump when binary operations involved - proxy reference has been fixed. weakref.ReferenceError is now a - built-in exception. - -- unicode(obj) now behaves more like str(obj), accepting arbitrary - objects, and calling a __unicode__ method if it exists. - unicode(obj, encoding) and unicode(obj, encoding, errors) still - require an 8-bit string or character buffer argument. - -- isinstance() now allows any object as the first argument and a - class, a type or something with a __bases__ tuple attribute for the - second argument. The second argument may also be a tuple of a - class, type, or something with __bases__, in which case isinstance() - will return true if the first argument is an instance of any of the - things contained in the second argument tuple. E.g. - - isinstance(x, (A, B)) - - returns true if x is an instance of A or B. - -Extension modules ------------------ - -- thread.start_new_thread() now returns the thread ID (previously None). - -- binascii has now two quopri support functions, a2b_qp and b2a_qp. - -- readline now supports setting the startup_hook and the - pre_event_hook, and adds the add_history() function. - -- os and posix supports chroot(), setgroups() and unsetenv() where - available. The stat(), fstat(), statvfs() and fstatvfs() functions - now return "pseudo-sequences" -- the various fields can now be - accessed as attributes (e.g. os.stat("/").st_mtime) but for - backwards compatibility they also behave as a fixed-length sequence. - Some platform-specific fields (e.g. st_rdev) are only accessible as - attributes. - -- time: localtime(), gmtime() and strptime() now return a - pseudo-sequence similar to the os.stat() return value, with - attributes like tm_year etc. - -- Decompression objects in the zlib module now accept an optional - second parameter to decompress() that specifies the maximum amount - of memory to use for the uncompressed data. - -- optional SSL support in the socket module now exports OpenSSL - functions RAND_add(), RAND_egd(), and RAND_status(). These calls - are useful on platforms like Solaris where OpenSSL does not - automatically seed its PRNG. Also, the keyfile and certfile - arguments to socket.ssl() are now optional. - -- posixmodule (and by extension, the os module on POSIX platforms) now - exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW. - -Library -------- - -- doctest now excludes functions and classes not defined by the module - being tested, thanks to Tim Hochberg. - -- HotShot, a new profiler implemented using a C-based callback, has - been added. This substantially reduces the overhead of profiling, - but it is still quite preliminary. Support modules and - documentation will be added in upcoming releases (before 2.2 final). - -- profile now produces correct output in situations where an exception - raised in Python is cleared by C code (e.g. hasattr()). This used - to cause wrong output, including spurious claims of recursive - functions and attribution of time spent to the wrong function. - - The code and documentation for the derived OldProfile and HotProfile - profiling classes was removed. The code hasn't worked for years (if - you tried to use them, they raised exceptions). OldProfile - intended to reproduce the behavior of the profiler Python used more - than 7 years ago, and isn't interesting anymore. HotProfile intended - to provide a faster profiler (but producing less information), and - that's a worthy goal we intend to meet via a different approach (but - without losing information). - -- Profile.calibrate() has a new implementation that should deliver - a much better system-specific calibration constant. The constant can - now be specified in an instance constructor, or as a Profile class or - instance variable, instead of by editing profile.py's source code. - Calibration must still be done manually (see the docs for the profile - module). - - Note that Profile.calibrate() must be overridden by subclasses. - Improving the accuracy required exploiting detailed knowledge of - profiler internals; the earlier method abstracted away the details - and measured a simplified model instead, but consequently computed - a constant too small by a factor of 2 on some modern machines. - -- quopri's encode and decode methods take an optional header parameter, - which indicates whether output is intended for the header 'Q' - encoding. - -- The SocketServer.ThreadingMixIn class now closes the request after - finish_request() returns. (Not when it errors out though.) - -- The nntplib module's NNTP.body() method has grown a 'file' argument - to allow saving the message body to a file. - -- The email package has added a class email.Parser.HeaderParser which - only parses headers and does not recurse into the message's body. - Also, the module/class MIMEAudio has been added for representing - audio data (contributed by Anthony Baxter). - -- ftplib should be able to handle files > 2GB. - -- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO, - ON, and OFF. - -- xml.dom.minidom NodeList objects now support the length attribute - and item() method as required by the DOM specifications. - Tools/Demos ----------- -- Demo/dns was removed. It no longer serves any purpose; a package - derived from it is now maintained by Anthony Baxter, see - http://PyDNS.SourceForge.net. - -- The freeze tool has been made more robust, and two new options have - been added: -X and -E. - -Build ------ - -- configure will use CXX in LINKCC if CXX is used to build main() and - the system requires to link a C++ main using the C++ compiler. - -C API ------ - -- The documentation for the tp_compare slot is updated to require that - the return value must be -1, 0, 1; an arbitrary number <0 or >0 is - not correct. This is not yet enforced but will be enforced in - Python 2.3; even later, we may use -2 to indicate errors and +2 for - "NotImplemented". Right now, -1 should be used for an error return. - -- PyLong_AsLongLong() now accepts int (as well as long) arguments. - Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well - as long) arguments. - -- PyThread_start_new_thread() now returns a long int giving the thread - ID, if one can be calculated; it returns -1 for error, 0 if no - thread ID is calculated (this is an incompatible change, but only - the thread module used this API). This code has only really been - tested on Linux and Windows; other platforms please beware (and - report any bugs or strange behavior). - -- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as - input. - -New platforms -------------- - -Tests ------ - -Windows -------- - -- Installer: If you install IDLE, and don't disable file-extension - registration, a new "Edit with IDLE" context (right-click) menu entry - is created for .py and .pyw files. - -- The signal module now supports SIGBREAK on Windows, thanks to Steven - Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK - action remains to call Win32 ExitProcess(). This can be changed via - signal.signal(). For example:: - - # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C - # (SIGINT) behavior. - import signal - signal.signal(signal.SIGBREAK, signal.default_int_handler) - - try: - while 1: - pass - except KeyboardInterrupt: - # We get here on Ctrl+C or Ctrl+Break now; if we had not changed - # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the - # program without the possibility for any Python-level cleanup). - print "Clean exit" - - -What's New in Python 2.2a4? -=========================== - -*Release date: 28-Sep-2001* - -Type/class unification and new-style classes --------------------------------------------- - -- pydoc and inspect are now aware of new-style classes; - e.g. help(list) at the interactive prompt now shows proper - documentation for all operations on list objects. - -- Applications using Jim Fulton's ExtensionClass module can now safely - be used with Python 2.2. In particular, Zope 2.4.1 now works with - Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass - examples also work again. It is hoped that Gtk and Boost also work - with 2.2a4 and beyond. (If you can confirm this, please write - webmaster@python.org; if there are still problems, please open a bug - report on SourceForge.) - -- property() now takes 4 keyword arguments: fget, fset, fdel and doc. - These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__' - in the constructed property object. fget, fset and fdel weren't - discoverable from Python in 2.2a3. __doc__ is new, and allows to - associate a docstring with a property. - -- Comparison overloading is now more completely implemented. For - example, a str subclass instance can properly be compared to a str - instance, and it can properly overload comparison. Ditto for most - other built-in object types. - -- The repr() of new-style classes has changed; instead of <type - 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>, - *except* for built-in types, which are still rendered as <type - 'Foo'> (to avoid upsetting existing code that might parse or - otherwise rely on repr() of certain type objects). - -- The repr() of new-style objects is now always <Foo object at XXX>; - previously, it was sometimes <Foo instance at XXX>. - -- For new-style classes, what was previously called __getattr__ is now - called __getattribute__. This method, if defined, is called for - *every* attribute access. A new __getattr__ hook more similar to the - one in classic classes is defined which is called only if regular - attribute access raises AttributeError; to catch *all* attribute - access, you can use __getattribute__ (for new-style classes). If - both are defined, __getattribute__ is called first, and if it raises - AttributeError, __getattr__ is called. - -- The __class__ attribute of new-style objects can be assigned to. - The new class must have the same C-level object layout as the old - class. - -- The builtin file type can be subclassed now. In the usual pattern, - "file" is the name of the builtin type, and file() is a new builtin - constructor, with the same signature as the builtin open() function. - file() is now the preferred way to open a file. - -- Previously, __new__ would only see sequential arguments passed to - the type in a constructor call; __init__ would see both sequential - and keyword arguments. This made no sense whatsoever any more, so - now both __new__ and __init__ see all arguments. - -- Previously, hash() applied to an instance of a subclass of str or - unicode always returned 0. This has been repaired. - -- Previously, an operation on an instance of a subclass of an - immutable type (int, long, float, complex, tuple, str, unicode), - where the subtype didn't override the operation (and so the - operation was handled by the builtin type), could return that - instance instead a value of the base type. For example, if s was of - a str subclass type, s[:] returned s as-is. Now it returns a str - with the same value as s. - -- Provisional support for pickling new-style objects has been added. - -Core ----- - -- file.writelines() now accepts any iterable object producing strings. - -- PyUnicode_FromEncodedObject() now works very much like - PyObject_Str(obj) in that it tries to use __str__/tp_str - on the object if the object is not a string or buffer. This - makes unicode() behave like str() when applied to non-string/buffer - objects. - -- PyFile_WriteObject now passes Unicode objects to the file's write - method. As a result, all file-like objects which may be the target - of a print statement must support Unicode objects, i.e. they must - at least convert them into ASCII strings. - -- Thread scheduling on Solaris should be improved; it is no longer - necessary to insert a small sleep at the start of a thread in order - to let other runnable threads be scheduled. - -Library -------- - -- StringIO.StringIO instances and cStringIO.StringIO instances support - read character buffer compatible objects for their .write() methods. - These objects are converted to strings and then handled as such - by the instances. - -- The "email" package has been added. This is basically a port of the - mimelib package <http://sf.net/projects/mimelib> with API changes - and some implementations updated to use iterators and generators. - -- difflib.ndiff() and difflib.Differ.compare() are generators now. This - restores the ability of Tools/scripts/ndiff.py to start producing output - before the entire comparison is complete. - -- StringIO.StringIO instances and cStringIO.StringIO instances support - iteration just like file objects (i.e. their .readline() method is - called for each iteration until it returns an empty string). - -- The codecs module has grown four new helper APIs to access - builtin codecs: getencoder(), getdecoder(), getreader(), - getwriter(). - -- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer) - simplifies writing XML RPC servers. - -- os.path.realpath(): a new function that returns the absolute pathname - after interpretation of symbolic links. On non-Unix systems, this - is an alias for os.path.abspath(). - -- operator.indexOf() (PySequence_Index() in the C API) now works with any - iterable object. - -- smtplib now supports various authentication and security features of - the SMTP protocol through the new login() and starttls() methods. - -- hmac: a new module implementing keyed hashing for message - authentication. - -- mimetypes now recognizes more extensions and file types. At the - same time, some mappings not sanctioned by IANA were removed. - -- The "compiler" package has been brought up to date to the state of - Python 2.2 bytecode generation. It has also been promoted from a - Tool to a standard library package. (Tools/compiler still exists as - a sample driver.) - -Build ------ - -- Large file support (LFS) is now automatic when the platform supports - it; no more manual configuration tweaks are needed. On Linux, at - least, it's possible to have a system whose C library supports large - files but whose kernel doesn't; in this case, large file support is - still enabled but doesn't do you any good unless you upgrade your - kernel or share your Python executable with another system whose - kernel has large file support. - -- The configure script now supplies plausible defaults in a - cross-compilation environment. This doesn't mean that the supplied - values are always correct, or that cross-compilation now works - flawlessly -- but it's a first step (and it shuts up most of - autoconf's warnings about AC_TRY_RUN). - -- The Unix build is now a bit less chatty, courtesy of the parser - generator. The build is completely silent (except for errors) when - using "make -s", thanks to a -q option to setup.py. - -C API ------ - -- The "structmember" API now supports some new flag bits to deny read - and/or write access to attributes in restricted execution mode. - -New platforms -------------- - -- Compaq's iPAQ handheld, running the "familiar" Linux distribution - (http://familiar.handhelds.org). - -Tests ------ - -- The "classic" standard tests, which work by comparing stdout to - an expected-output file under Lib/test/output/, no longer stop at - the first mismatch. Instead the test is run to completion, and a - variant of ndiff-style comparison is used to report all differences. - This is much easier to understand than the previous style of reporting. - -- The unittest-based standard tests now use regrtest's test_main() - convention, instead of running as a side-effect of merely being - imported. This allows these tests to be run in more natural and - flexible ways as unittests, outside the regrtest framework. - -- regrtest.py is much better integrated with unittest and doctest now, - especially in regard to reporting errors. - -Windows -------- - -- Large file support now also works for files > 4GB, on filesystems - that support it (NTFS under Windows 2000). See "What's New in - Python 2.2a3" for more detail. - - -What's New in Python 2.2a3? -=========================== - -*Release Date: 07-Sep-2001* - -Core ----- - -- Conversion of long to float now raises OverflowError if the long is too - big to represent as a C double. - -- The 3-argument builtin pow() no longer allows a third non-None argument - if either of the first two arguments is a float, or if both are of - integer types and the second argument is negative (in which latter case - the arguments are converted to float, so this is really the same - restriction). - -- The builtin dir() now returns more information, and sometimes much - more, generally naming all attributes of an object, and all attributes - reachable from the object via its class, and from its class's base - classes, and so on from them too. Example: in 2.2a2, dir([]) returned - an empty list. In 2.2a3, - - >>> dir([]) - ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', - '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__', - '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__', - '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__', - '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__', - 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', - 'reverse', 'sort'] - - dir(module) continues to return only the module's attributes, though. - -- Overflowing operations on plain ints now return a long int rather - than raising OverflowError. This is a partial implementation of PEP - 237. You can use -Wdefault::OverflowWarning to enable a warning for - this situation, and -Werror::OverflowWarning to revert to the old - OverflowError exception. - -- A new command line option, -Q<arg>, is added to control run-time - warnings for the use of classic division. (See PEP 238.) Possible - values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is - -Qold, meaning the / operator has its classic meaning and no - warnings are issued. Using -Qwarn issues a run-time warning about - all uses of classic division for int and long arguments; -Qwarnall - also warns about classic division for float and complex arguments - (for use with fixdiv.py). - [Note: the remainder of this item (preserved below) became - obsolete in 2.2c1 -- -Qnew has global effect in 2.2] :: - - Using -Qnew is questionable; it turns on new division by default, but - only in the __main__ module. You can usefully combine -Qwarn or - -Qwarnall and -Qnew: this gives the __main__ module new division, and - warns about classic division everywhere else. - -- Many built-in types can now be subclassed. This applies to int, - long, float, str, unicode, and tuple. (The types complex, list and - dictionary can also be subclassed; this was introduced earlier.) - Note that restrictions apply when subclassing immutable built-in - types: you can only affect the value of the instance by overloading - __new__. You can add mutable attributes, and the subclass instances - will have a __dict__ attribute, but you cannot change the "value" - (as implemented by the base class) of an immutable subclass instance - once it is created. - -- The dictionary constructor now takes an optional argument, a - mapping-like object, and initializes the dictionary from its - (key, value) pairs. - -- A new built-in type, super, has been added. This facilitates making - "cooperative super calls" in a multiple inheritance setting. For an - explanation, see http://www.python.org/2.2/descrintro.html#cooperation - -- A new built-in type, property, has been added. This enables the - creation of "properties". These are attributes implemented by - getter and setter functions (or only one of these for read-only or - write-only attributes), without the need to override __getattr__. - See http://www.python.org/2.2/descrintro.html#property - -- The syntax of floating-point and imaginary literals has been - liberalized, to allow leading zeroes. Examples of literals now - legal that were SyntaxErrors before: - - 00.0 0e3 0100j 07.5 00000000000000000008. - -- An old tokenizer bug allowed floating point literals with an incomplete - exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError. - -Library -------- - -- telnetlib includes symbolic names for the options, and support for - setting an option negotiation callback. It also supports processing - of suboptions. - -- The new C standard no longer requires that math libraries set errno to - ERANGE on overflow. For platform libraries that exploit this new - freedom, Python's overflow-checking was wholly broken. A new overflow- - checking scheme attempts to repair that, but may not be reliable on all - platforms (C doesn't seem to provide anything both useful and portable - in this area anymore). - -- Asynchronous timeout actions are available through the new class - threading.Timer. - -- math.log and math.log10 now return sensible results for even huge - long arguments. For example, math.log10(10 ** 10000) ~= 10000.0. - -- A new function, imp.lock_held(), returns 1 when the import lock is - currently held. See the docs for the imp module. - -- pickle, cPickle and marshal on 32-bit platforms can now correctly read - dumps containing ints written on platforms where Python ints are 8 bytes. - When read on a box where Python ints are 4 bytes, such values are - converted to Python longs. - -- In restricted execution mode (using the rexec module), unmarshalling - code objects is no longer allowed. This plugs a security hole. - -- unittest.TestResult instances no longer store references to tracebacks - generated by test failures. This prevents unexpected dangling references - to objects that should be garbage collected between tests. - -Tools ------ - -- Tools/scripts/fixdiv.py has been added which can be used to fix - division operators as per PEP 238. - -Build ------ - -- If you are an adventurous person using Mac OS X you may want to look at - Mac/OSX. There is a Makefile there that will build Python as a real Mac - application, which can be used for experimenting with Carbon or Cocoa. - Discussion of this on pythonmac-sig, please. - -C API ------ - -- New function PyObject_Dir(obj), like Python __builtin__.dir(obj). - -- Note that PyLong_AsDouble can fail! This has always been true, but no - callers checked for it. It's more likely to fail now, because overflow - errors are properly detected now. The proper way to check:: - - double x = PyLong_AsDouble(some_long_object); - if (x == -1.0 && PyErr_Occurred()) { - /* The conversion failed. */ - } - -- The GC API has been changed. Extensions that use the old API will still - compile but will not participate in GC. To upgrade an extension - module: - - - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC - - - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and - PyObject_GC_Del to deallocate them - - - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini - to PyObject_GC_UnTrack - - - remove PyGC_HEAD_SIZE from object size calculations - - - remove calls to PyObject_AS_GC and PyObject_FROM_GC - -- Two new functions: PyString_FromFormat() and PyString_FromFormatV(). - These can be used safely to construct string objects from a - sprintf-style format string (similar to the format string supported - by PyErr_Format()). - -New platforms -------------- - -- Stephen Hansen contributed patches sufficient to get a clean compile - under Borland C (Windows), but he reports problems running it and ran - out of time to complete the port. Volunteers? Expect a MemoryError - when importing the types module; this is probably shallow, and - causing later failures too. - -Tests ------ - -Windows -------- - -- Large file support is now enabled on Win32 platforms as well as on - Win64. This means that, for example, you can use f.tell() and f.seek() - to manipulate files larger than 2 gigabytes (provided you have enough - disk space, and are using a Windows filesystem that supports large - partitions). Windows filesystem limits: FAT has a 2GB (gigabyte) - filesize limit, and large file support makes no difference there. - FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now. - NTFS has no practical limit on file size, and files of any size can be - used from Python now. - -- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC - points to command.com (patch from Brian Quinlan). - - -What's New in Python 2.2a2? -=========================== - -*Release Date: 22-Aug-2001* - -Build ------ - -- Tim Peters developed a brand new Windows installer using Wise 8.1, - generously donated to us by Wise Solutions. - -- configure supports a new option --enable-unicode, with the values - ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode - type and supporting code is completely removed from the interpreter. - -- A new configure option --enable-framework builds a Mac OS X framework, - which "make frameworkinstall" will install. This provides a starting - point for more mac-like functionality, join pythonmac-sig@python.org - if you are interested in helping. - -- The NeXT platform is no longer supported. - -- The 'new' module is now statically linked. - -Tools ------ - -- The new Tools/scripts/cleanfuture.py can be used to automatically - edit out obsolete future statements from Python source code. See - the module docstring for details. - -Tests ------ - -- regrtest.py now knows which tests are expected to be skipped on some - platforms, allowing to give clearer test result output. regrtest - also has optional --use/-u switch to run normally disabled tests - which require network access or consume significant disk resources. - -- Several new tests in the standard test suite, with special thanks to - Nick Mathewson. - -Core ----- - -- The floor division operator // has been added as outlined in PEP - 238. The / operator still provides classic division (and will until - Python 3.0) unless "from __future__ import division" is included, in - which case the / operator will provide true division. The operator - module provides truediv() and floordiv() functions. Augmented - assignment variants are included, as are the equivalent overloadable - methods and C API methods. See the PEP for a full discussion: - <http://python.sf.net/peps/pep-0238.html> - -- Future statements are now effective in simulated interactive shells - (like IDLE). This should "just work" by magic, but read Michael - Hudson's "Future statements in simulated shells" PEP 264 for full - details: <http://python.sf.net/peps/pep-0264.html>. - -- The type/class unification (PEP 252-253) was integrated into the - trunk and is not so tentative any more (the exact specification of - some features is still tentative). A lot of work has done on fixing - bugs and adding robustness and features (performance still has to - come a long way). - -- Warnings about a mismatch in the Python API during extension import - now use the Python warning framework (which makes it possible to - write filters for these warnings). - -- A function's __dict__ (aka func_dict) will now always be a - dictionary. It used to be possible to delete it or set it to None, - but now both actions raise TypeErrors. It is still legal to set it - to a dictionary object. Getting func.__dict__ before any attributes - have been assigned now returns an empty dictionary instead of None. - -- A new command line option, -E, was added which disables the use of - all environment variables, or at least those that are specifically - significant to Python. Usually those have a name starting with - "PYTHON". This was used to fix a problem where the tests fail if - the user happens to have PYTHONHOME or PYTHONPATH pointing to an - older distribution. - -Library -------- - -- New class Differ and new functions ndiff() and restore() in difflib.py. - These package the algorithms used by the popular Tools/scripts/ndiff.py, - for programmatic reuse. - -- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute - value using the minimal quoting required for the value; more - reliable than using xml.sax.saxutils.escape() for attribute values. - -- Readline completion support for cmd.Cmd was added. - -- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings. - -- Added function threading.BoundedSemaphore() - -- Added Ka-Ping Yee's cgitb.py module. - -- The 'new' module now exposes the CO_xxx flags. - -- The gc module offers the get_referents function. - -New platforms -------------- - -C API ------ - -- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added - which provide a cross-platform implementations for the - relatively new snprintf()/vsnprintf() C lib APIs. In contrast to - the standard sprintf() and vsprintf() C lib APIs, these versions - apply bounds checking on the used buffer which enhances protection - against buffer overruns. - -- Unicode APIs now use name mangling to assure that mixing interpreters - and extensions using different Unicode widths is rendered next to - impossible. Trying to import an incompatible Unicode-aware extension - will result in an ImportError. Unicode extensions writers must make - sure to check the Unicode width compatibility in their extensions by - using at least one of the mangled Unicode APIs in the extension. - -- Two new flags METH_NOARGS and METH_O are available in method definition - tables to simplify implementation of methods with no arguments and a - single untyped argument. Calling such methods is more efficient than - calling corresponding METH_VARARGS methods. METH_OLDARGS is now - deprecated. - -Windows -------- - -- "import module" now compiles module.pyw if it exists and nothing else - relevant is found. - - -What's New in Python 2.2a1? -=========================== - -*Release date: 18-Jul-2001* - -Core ----- - -- TENTATIVELY, a large amount of code implementing much of what's - described in PEP 252 (Making Types Look More Like Classes) and PEP - 253 (Subtyping Built-in Types) was added. This will be released - with Python 2.2a1. Documentation will be provided separately - through http://www.python.org/2.2/. The purpose of releasing this - with Python 2.2a1 is to test backwards compatibility. It is - possible, though not likely, that a decision is made not to release - this code as part of 2.2 final, if any serious backwards - incompatibilities are found during alpha testing that cannot be - repaired. - -- Generators were added; this is a new way to create an iterator (see - below) using what looks like a simple function containing one or - more 'yield' statements. See PEP 255. Since this adds a new - keyword to the language, this feature must be enabled by including a - future statement: "from __future__ import generators" (see PEP 236). - Generators will become a standard feature in a future release - (probably 2.3). Without this future statement, 'yield' remains an - ordinary identifier, but a warning is issued each time it is used. - (These warnings currently don't conform to the warnings framework of - PEP 230; we intend to fix this in 2.2a2.) - -- The UTF-16 codec was modified to be more RFC compliant. It will now - only remove BOM characters at the start of the string and then - only if running in native mode (UTF-16-LE and -BE won't remove a - leading BMO character). - -- Strings now have a new method .decode() to complement the already - existing .encode() method. These two methods provide direct access - to the corresponding decoders and encoders of the registered codecs. - - To enhance the usability of the .encode() method, the special - casing of Unicode object return values was dropped (Unicode objects - were auto-magically converted to string using the default encoding). - - Both methods will now return whatever the codec in charge of the - requested encoding returns as object, e.g. Unicode codecs will - return Unicode objects when decoding is requested ("äöü".decode("latin-1") - will return u"äöü"). This enables codec writer to create codecs - for various simple to use conversions. - - New codecs were added to demonstrate these new features (the .encode() - and .decode() columns indicate the type of the returned objects): - - +---------+-----------+-----------+-----------------------------+ - |Name | .encode() | .decode() | Description | - +=========+===========+===========+=============================+ - |uu | string | string | UU codec (e.g. for email) | - +---------+-----------+-----------+-----------------------------+ - |base64 | string | string | base64 codec | - +---------+-----------+-----------+-----------------------------+ - |quopri | string | string | quoted-printable codec | - +---------+-----------+-----------+-----------------------------+ - |zlib | string | string | zlib compression | - +---------+-----------+-----------+-----------------------------+ - |hex | string | string | 2-byte hex codec | - +---------+-----------+-----------+-----------------------------+ - |rot-13 | string | Unicode | ROT-13 Unicode charmap codec| - +---------+-----------+-----------+-----------------------------+ - -- Some operating systems now support the concept of a default Unicode - encoding for file system operations. Notably, Windows supports 'mbcs' - as the default. The Macintosh will also adopt this concept in the medium - term, although the default encoding for that platform will be other than - 'mbcs'. - - On operating system that support non-ASCII filenames, it is common for - functions that return filenames (such as os.listdir()) to return Python - string objects pre-encoded using the default file system encoding for - the platform. As this encoding is likely to be different from Python's - default encoding, converting this name to a Unicode object before passing - it back to the Operating System would result in a Unicode error, as Python - would attempt to use its default encoding (generally ASCII) rather than - the default encoding for the file system. - - In general, this change simply removes surprises when working with - Unicode and the file system, making these operations work as you expect, - increasing the transparency of Unicode objects in this context. - See [????] for more details, including examples. - -- Float (and complex) literals in source code were evaluated to full - precision only when running from a .py file; the same code loaded from a - .pyc (or .pyo) file could suffer numeric differences starting at about the - 12th significant decimal digit. For example, on a machine with IEEE-754 - floating arithmetic, - - x = 9007199254740992.0 - print long(x) - - printed 9007199254740992 if run directly from .py, but 9007199254740000 - if from a compiled (.pyc or .pyo) file. This was due to marshal using - str(float) instead of repr(float) when building code objects. marshal - now uses repr(float) instead, which should reproduce floats to full - machine precision (assuming the platform C float<->string I/O conversion - functions are of good quality). - - This may cause floating-point results to change in some cases, and - usually for the better, but may also cause numerically unstable - algorithms to break. - -- The implementation of dicts suffers fewer collisions, which has speed - benefits. However, the order in which dict entries appear in dict.keys(), - dict.values() and dict.items() may differ from previous releases for a - given dict. Nothing is defined about this order, so no program should - rely on it. Nevertheless, it's easy to write test cases that rely on the - order by accident, typically because of printing the str() or repr() of a - dict to an "expected results" file. See Lib/test/test_support.py's new - sortdict(dict) function for a simple way to display a dict in sorted - order. - -- Many other small changes to dicts were made, resulting in faster - operation along the most common code paths. - -- Dictionary objects now support the "in" operator: "x in dict" means - the same as dict.has_key(x). - -- The update() method of dictionaries now accepts generic mapping - objects. Specifically the argument object must support the .keys() - and __getitem__() methods. This allows you to say, for example, - {}.update(UserDict()) - -- Iterators were added; this is a generalized way of providing values - to a for loop. See PEP 234. There's a new built-in function iter() - to return an iterator. There's a new protocol to get the next value - from an iterator using the next() method (in Python) or the - tp_iternext slot (in C). There's a new protocol to get iterators - using the __iter__() method (in Python) or the tp_iter slot (in C). - Iterating (i.e. a for loop) over a dictionary generates its keys. - Iterating over a file generates its lines. - -- The following functions were generalized to work nicely with iterator - arguments:: - - map(), filter(), reduce(), zip() - list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API) - max(), min() - join() method of strings - extend() method of lists - 'x in y' and 'x not in y' (PySequence_Contains() in C API) - operator.countOf() (PySequence_Count() in C API) - right-hand side of assignment statements with multiple targets, such as :: - x, y, z = some_iterable_object_returning_exactly_3_values - -- Accessing module attributes is significantly faster (for example, - random.random or os.path or yourPythonModule.yourAttribute). - -- Comparing dictionary objects via == and != is faster, and now works even - if the keys and values don't support comparisons other than ==. - -- Comparing dictionaries in ways other than == and != is slower: there were - insecurities in the dict comparison implementation that could cause Python - to crash if the element comparison routines for the dict keys and/or - values mutated the dicts. Making the code bulletproof slowed it down. - -- Collisions in dicts are resolved via a new approach, which can help - dramatically in bad cases. For example, looking up every key in a dict - d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x - faster now. Thanks to Christian Tismer for pointing out the cause and - the nature of an effective cure (last December! better late than never). - -- repr() is much faster for large containers (dict, list, tuple). - - -Library -------- - -- The constants ascii_letters, ascii_lowercase. and ascii_uppercase - were added to the string module. These a locale-independent - constants, unlike letters, lowercase, and uppercase. These are now - use in appropriate locations in the standard library. - -- The flags used in dlopen calls can now be configured using - sys.setdlopenflags and queried using sys.getdlopenflags. - -- Fredrik Lundh's xmlrpclib is now a standard library module. This - provides full client-side XML-RPC support. In addition, - Demo/xmlrpc/ contains two server frameworks (one SocketServer-based, - one asyncore-based). Thanks to Eric Raymond for the documentation. - -- The xrange() object is simplified: it no longer supports slicing, - repetition, comparisons, efficient 'in' checking, the tolist() - method, or the start, stop and step attributes. See PEP 260. - -- A new function fnmatch.filter to filter lists of file names was added. - -- calendar.py uses month and day names based on the current locale. - -- strop is now *really* obsolete (this was announced before with 1.6), - and issues DeprecationWarning when used (except for the four items - that are still imported into string.py). - -- Cookie.py now sorts key+value pairs by key in output strings. - -- pprint.isrecursive(object) didn't correctly identify recursive objects. - Now it does. - -- pprint functions now much faster for large containers (tuple, list, dict). - -- New 'q' and 'Q' format codes in the struct module, corresponding to C - types "long long" and "unsigned long long" (on Windows, __int64). In - native mode, these can be used only when the platform C compiler supports - these types (when HAVE_LONG_LONG is #define'd by the Python config - process), and then they inherit the sizes and alignments of the C types. - In standard mode, 'q' and 'Q' are supported on all platforms, and are - 8-byte integral types. - -- The site module installs a new built-in function 'help' that invokes - pydoc.help. It must be invoked as 'help()'; when invoked as 'help', - it displays a message reminding the user to use 'help()' or - 'help(object)'. - -Tests ------ - -- New test_mutants.py runs dict comparisons where the key and value - comparison operators mutate the dicts randomly during comparison. This - rapidly causes Python to crash under earlier releases (not for the faint - of heart: it can also cause Win9x to freeze or reboot!). - -- New test_pprint.py verifies that pprint.isrecursive() and - pprint.isreadable() return sensible results. Also verifies that simple - cases produce correct output. - -C API ------ - -- Removed the unused last_is_sticky argument from the internal - _PyTuple_Resize(). If this affects you, you were cheating. - ----- - **(For information about older versions, consult the HISTORY file.)** |