blob: a454e1840a16bbd11ba5a077ace389006b2fc28c [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +00009- u'%c' will now raise a ValueError in case the argument is an
10 integer outside the valid range of Unicode code point ordinals.
11
Guido van Rossumdeb09362002-08-09 17:16:30 +000012- The tempfile module has been overhauled for enhanced security. The
13 mktemp() function is now deprecated; new, safe replacements are
14 mkstemp() (for files) and mkdtemp() (for directories), and the
15 higher-level functions NamedTemporaryFile() and TemporaryFile().
16 Use of some global variables in this module is also deprecated; the
17 new functions have keyword arguments to provide the same
18 functionality. All Lib, Tools and Demo modules that used the unsafe
19 interfaces have been updated to use the safe replacements. Thanks
20 to Zack Weinberg!
21
Guido van Rossumd81a9832002-08-09 15:57:34 +000022- When x is an object whose class implements __mul__ and __rmul__,
23 1.0*x would correctly invoke __rmul__, but 1*x would erroneously
24 invoke __mul__. This was due to the sequence-repeat code in the int
25 type. This has been fixed now.
26
Barry Warsawd79f6832002-08-06 17:01:51 +000027- Previously, "str1 in str2" required str1 to be a string of length 1.
28 This restriction has been relaxed to allow str1 to be a string of
29 any length. Thus "'el' in 'hello world'" returns True now.
30
Guido van Rossumb57089c2002-08-06 16:20:26 +000031- File objects are now their own iterators. For a file f, iter(f) now
32 returns f (unless f is closed), and f.next() is similar to
33 f.readline() when EOF is not reached; however, f.next() uses a
34 readahead buffer that messes up the file position, so mixing
35 f.next() and f.readline() (or other methods) doesn't work right.
36 Calling f.seek() drops the readahead buffer, but other operations
37 don't. It so happens that this gives a nice additional speed boost
38 to "for line in file:"; the xreadlines method and corresponding
Guido van Rossumbffb2ef2002-08-09 17:17:07 +000039 module are now obsolete. Thanks to Oren Tirosh!
Guido van Rossumb57089c2002-08-06 16:20:26 +000040
Guido van Rossumde392d32002-08-05 14:17:20 +000041- Encoding declarations (PEP 263, phase 1) have been implemented. A
42 comment of the form "# -*- coding: <encodingname> -*-" in the first
43 or second line of a Python source file indicates the encoding.
Martin v. Löwis00f1e3f2002-08-04 17:29:52 +000044
Tim Petersf47630f2002-08-01 02:34:51 +000045- list.sort() has a new implementation. While cross-platform results
46 may vary, and in data-dependent ways, this is much faster on many
47 kinds of partially ordered lists than the previous implementation,
48 and reported to be just as fast on randomly ordered lists on
49 several major platforms. This sort is also stable (if A==B and A
50 precedes B in the list at the start, A precedes B after the sort too),
51 although the language definition does not guarantee stability. A
52 potential drawback is that list.sort() may require temp space of
53 len(list)*2 bytes (*4 on a 64-bit machine). It's therefore possible
54 for list.sort() to raise MemoryError now, even if a comparison function
55 does not. See <http://www.python.org/sf/587076> for full details.
56
Guido van Rossum2d5389c2002-07-23 03:44:35 +000057- All standard iterators now ensure that, once StopIteration has been
58 raised, all future calls to next() on the same iterator will also
59 raise StopIteration. There used to be various counterexamples to
60 this behavior, which could caused confusion or subtle program
61 breakage, without any benefits. (Note that this is still an
62 iterator's responsibility; the iterator framework does not enforce
63 this.)
64
Mark Hammondc0e35152002-07-16 01:32:30 +000065- Ctrl+C handling on Windows has been made more consistent with
66 other platforms. KeyboardInterrupt can now reliably be caught,
Tim Petersf47630f2002-08-01 02:34:51 +000067 and Ctrl+C at an interative prompt no longer terminates the
Mark Hammondc0e35152002-07-16 01:32:30 +000068 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
Mark Hammond8f3afc72002-08-10 06:26:31 +000069 interrupt time.sleep() in the main thread, and any child processes
70 created via the popen family (on win2k; we can't make win9x work
71 reliably) are also interrupted (as generally happens on for Linux/Unix.)
72 [SF bugs 231273, 439992 and 581232]
Mark Hammondc0e35152002-07-16 01:32:30 +000073
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000074- Slices and repetitions of buffer objects now consistently return
75 a string. Formerly, strings would be returned most of the time,
76 but a buffer object would be returned when the repetition count
77 was one or when the slice range was all inclusive.
78
Guido van Rossumc7c36502002-06-21 01:29:25 +000079- The __slots__ variable can now mention "private" names, and the
80 right thing will happen (e.g. __slots__ = ["__foo"]).
81
Walter Dörwald3430d702002-06-17 10:43:59 +000082- Unicode objects in sys.path are no longer ignored but treated
83 as directory names.
84
Guido van Rossum9562bcf2002-06-14 21:31:18 +000085- The built-ins slice() and buffer() are now callable types. The
86 types classobj (formerly class), code, function, instance, and
87 instancemethod (formerly instance-method), which have no built-in
88 names but are accessible through the types module, are now also
89 callable. The type dict-proxy is renamed to dictproxy.
90
Neal Norwitz1f68fc72002-06-14 00:50:42 +000091- Fixed string.startswith and string.endswith builtin methods
92 so they accept negative indices. [SF bug 493951]
93
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000094- Fixed a bug with a continue inside a try block and a yield in the
95 finally clause. [SF bug 567538]
96
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000097- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000098 with a third "stride" parameter. For example, "hello world"[::-1]
99 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +0000100
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000101- Cycles going through the __class__ link of a new-style instance are
102 now detected by the garbage collector.
103
Guido van Rossum9923ffe2002-06-04 19:52:53 +0000104- Classes using __slots__ are now properly garbage collected.
105 [SF bug 519621]
106
107- Tightened the __slots__ rules: a slot name must be a valid Python
108 identifier.
109
Guido van Rossum2e4e0262002-06-04 05:58:34 +0000110- The constructor for the module type now requires a name argument and
111 takes an optional docstring argument. Previously, this constructor
112 ignored its arguments. As a consequence, deriving a class from a
113 module (not from the module type) is now illegal; previously this
114 created an unnamed module, just like invoking the module type did.
115 [SF bug 563060]
116
Neal Norwitzd68f5172002-05-29 15:54:55 +0000117- A new warning PendingDeprecationWarning was added to provide
118 direction on features which are in the process of being deprecated.
119 The warning will not be printed by default. To see the pending
120 deprecations, use -Walways::PendingDeprecationWarning::
121 as a command line option or warnings.filterwarnings() in code.
122
Neal Norwitz32a7e7f2002-05-31 19:58:02 +0000123- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +0000124 for 'str' and 'unicode', and can be used instead of
125 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +0000126 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +0000127 is an abstract base class and cannot be instantiated directly.
128
Fred Draked0ba6362002-05-02 21:28:26 +0000129- Deprecated features of xrange objects have been removed as
130 promised. The start, stop, and step attributes and the tolist()
131 method no longer exist. xrange repetition and slicing have been
132 removed.
133
Guido van Rossum7dab2422002-04-26 19:40:56 +0000134- New builtin function enumerate(x), from PEP 279. Example:
135 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
136 The argument can be an arbitrary iterable object.
137
Neil Schemenauer89e3ee02002-04-26 01:58:53 +0000138- The assert statement no longer tests __debug__ at runtime. This means
139 that assert statements cannot be disabled by assigning a false value
140 to __debug__.
141
Walter Dörwald068325e2002-04-15 13:36:47 +0000142- A method zfill() was added to str and unicode, that fills a numeric
143 string to the left with zeros. For example,
144 "+123".zfill(6) -> "+00123".
145
Guido van Rossum862fe3c2002-04-15 12:36:47 +0000146- Complex numbers supported divmod() and the // and % operators, but
147 these make no sense. Since this was documented, they're being
148 deprecated now.
149
Guido van Rossum26dd8302002-04-26 20:11:29 +0000150- String and unicode methods lstrip(), rstrip() and strip() now take
151 an optional argument that specifies the characters to strip. For
152 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000153
Guido van Rossumc69343b2002-04-12 19:22:48 +0000154- Added a new dict method pop(key). This removes and returns the
155 value corresponding to key. [SF patch #539949]
156
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000157- Changed new-style class instantiation so that when C's __new__
158 method returns something that's not a C instance, its __init__ is
159 not called. [SF bug #537450]
160
Guido van Rossum181e41a2002-04-06 00:23:25 +0000161- Fixed super() to work correctly with class methods. [SF bug #535444]
162
Guido van Rossum47834462002-04-04 15:21:33 +0000163- A new built-in type, bool, has been added, as well as built-in
164 names for its two values, True and False. Comparisons and sundry
165 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000166 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000167 is backward compatible.
168
Guido van Rossum95b62a62002-03-29 01:07:24 +0000169- Fixed two bugs reported as SF #535905: under certain conditions,
170 deallocating a deeply nested structure could cause a segfault in the
171 garbage collector, due to interaction with the "trashcan" code;
172 access to the current frame during destruction of a local variable
173 could access a pointer to freed memory.
174
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000175- The optional object allocator ("pymalloc") has been enabled by
176 default. The recommended practice for memory allocation and
177 deallocation has been streamlined. A header file is included,
178 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
179 and lets them use the same API with Python versions from 1.5.2
180 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000181
Guido van Rossum8c842552002-03-14 23:05:54 +0000182- If you try to pickle an instance of a class that has __slots__ but
183 doesn't define or override __getstate__, a TypeError is now raised.
184 This is done by adding a bozo __getstate__ to the class that always
185 raises TypeError. (Before, this would appear to be pickled, but the
186 state of the slots would be lost.)
187
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000188- PyErr_Display will provide file and line information for all exceptions
189 that have an attribute print_file_and_line, not just SyntaxErrors.
190
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000191- The UTF-8 codec will now encode and decode Unicode surrogates
192 correctly and without raising exceptions for unpaired ones.
193
Neal Norwitz649b7592002-01-01 19:07:13 +0000194- file.xreadlines() now raises a ValueError if the file is closed:
195 Previously, an xreadlines object was returned which would raise
196 a ValueError when the xreadlines.next() method was called.
197
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000198- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000199 An exception will now be raised if more than one argument is used.
200
Tim Petersaf8446f2001-12-21 21:36:50 +0000201Extension modules
202
Guido van Rossumb57089c2002-08-06 16:20:26 +0000203- The xreadlines module is slated for obsolescence.
204
Guido van Rossum79f0a102002-07-23 03:32:08 +0000205- The strptime function in the time module is now always available (a
206 Python implementation is used when the C library doesn't define it).
207
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000208- The 'new' module is no longer an extension, but a Python module that
209 only exists for backwards compatibility. Its contents are no longer
210 functions but callable type objects.
211
Tim Peters81b92512002-04-29 01:37:32 +0000212- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000213 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000214 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000215
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000216- posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been
217 added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000218
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000219- The locale module now exposes the C library's gettext interface.
220
Tim Petersfbf74f22002-03-14 19:06:01 +0000221- A security hole ("double free") was found in zlib-1.1.3, a popular
222 third party compression library used by some Python modules. The
223 hole was quickly plugged in zlib-1.1.4, and the Windows build of
224 Python now ships with zlib-1.1.4.
225
Martin v. Löwis688357e2002-04-08 21:28:20 +0000226- pwd, grp, and resource return enhanced tuples now, with symbolic
227 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000228
Martin v. Löwis99866332002-03-01 10:27:01 +0000229- array.array is now a type object. A new format character
230 'u' indicates Py_UNICODE arrays. For those, .tounicode and
231 .fromunicode methods are available. Arrays now support __iadd__
232 and __imul__.
233
Neal Norwitze790eae2002-01-01 21:14:12 +0000234- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000235 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
236 is called.
237
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000238- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
239 been added where available.
240
Tim Petersaf8446f2001-12-21 21:36:50 +0000241Library
242
Guido van Rossum4a57c332002-08-02 18:05:20 +0000243- New "algorithms" module: heapq, implements a heap queue. Thanks to
244 Kevin O'Connor for the code and François Pinard for an entertaining
245 write-up explaining the theory and practical uses of heaps.
246
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000247- New encoding for the Palm OS character set: palmos.
248
Tim Peters943382c2002-07-07 03:59:34 +0000249- binascii.crc32() and the zipfile module had problems on some 64-bit
250 platforms. These have been fixed. On a platform with 8-byte C longs,
251 crc32() now returns a signed-extended 4-byte result, so that its value
252 as a Python int is equal to the value computed a 32-bit platform.
253
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000254- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
255 argument.
256
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000257- Some fixes in the copy module: when an object is copied through its
258 __reduce__ method, there was no check for a __setstate__ method on
259 the result [SF patch 565085]; deepcopy should treat instances of
260 custom metaclasses the same way it treats instances of type 'type'
261 [SF patch 560794].
262
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000263- Sockets now support timeout mode. After s.settimeout(T), where T is
264 a float expressing seconds, subsequent operations raise an exception
265 if they cannot be completed within T seconds. To disable timeout
Guido van Rossum79f0a102002-07-23 03:32:08 +0000266 mode, use s.settimeout(None). There's also a module function,
267 socket.setdefaulttimeout(T), which sets the default for all sockets
268 created henceforth.
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000269
270- getopt.gnu_getopt was added. This supports GNU-style option
271 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000272
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000273- Stop using strings for exceptions. String objects used for
274 exceptions are now classes deriving from Exception. The objects
275 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
276 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000277
Walter Dörwald474458d2002-06-04 15:16:29 +0000278- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
279 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
280 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
281 big endian systems were added to the codecs module. The old names
282 BOM32_* and BOM64_* were off by a factor of 2.
283
Guido van Rossumf9257822002-06-18 20:43:18 +0000284- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000285
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000286- ftplib.retrlines() now tests for callback is None rather than testing
287 for False. Was causing an error when given a callback object which
288 was callable but also returned len() as zero. The change may
289 create new breakage if the caller relied on the undocumented behavior
290 and called with callback set to [] or some other False value not
291 identical to None.
292
Tim Peters46c04e12002-05-05 20:40:00 +0000293- random.gauss() uses a piece of hidden state used by nothing else,
294 and the .seed() and .whseed() methods failed to reset it. In other
295 words, setting the seed didn't completely determine the sequence of
296 results produced by random.gauss(). It does now. Programs repeatedly
297 mixing calls to a seed method with calls to gauss() may see different
298 results now.
299
Fred Drake7f781c92002-05-01 20:33:53 +0000300- The pickle.Pickler class grew a clear_memo() method to mimic that
301 provided by cPickle.Pickler.
302
Tim Peters81b92512002-04-29 01:37:32 +0000303- difflib's SequenceMatcher class now does a dynamic analysis of
304 which elements are so frequent as to constitute noise. For
305 comparing files as sequences of lines, this generally works better
306 than the IS_LINE_JUNK function, and function ndiff's linejunk
307 argument defaults to None now as a result. A happy benefit is
308 that SequenceMatcher may run much faster now when applied
309 to large files with many duplicate lines (for example, C program
310 text with lots of repeated "}" and "return NULL;" lines).
311
Guido van Rossum256705b2002-04-23 13:29:43 +0000312- New Text.dump() method in Tkinter module.
313
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000314- New distutils commands for building packagers were added to
315 support pkgtool on Solaris and swinstall on HP-UX.
316
317- distutils now has a new abstract binary packager base class
318 command/bdist_packager, which simplifies writing packagers.
319 This will hopefully provide the missing bits to encourage
320 people to submit more packagers, e.g. for Debian, FreeBSD
321 and other systems.
322
Guido van Rossumf9257822002-06-18 20:43:18 +0000323- The UTF-16, -LE and -BE stream readers now raise a
324 NotImplementedError for all calls to .readline(). Previously, they
325 used to just produce garbage or fail with an encoding error --
326 UTF-16 is a 2-byte encoding and the C lib's line reading APIs don't
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000327 work well with these.
328
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000329- compileall now supports quiet operation.
330
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000331- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000332 connections.
333
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000334- socket module: the SSL support was broken out of the main
335 _socket module C helper and placed into a new _ssl helper
336 which now gets imported by socket.py if available and working.
337
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000338- encodings package: added aliases for all supported IANA character
339 sets
340
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000341- ftplib: to safeguard the user's privacy, anonymous login will use
342 "anonymous@" as default password, rather than the real user and host
343 name.
344
Fred Drake36736122002-01-10 13:50:31 +0000345- webbrowser: tightened up the command passed to os.system() so that
346 arbitrary shell code can't be executed because a bogus URL was
347 passed in.
348
Tim Peters11bd9942002-02-01 00:52:29 +0000349- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000350 gettext.find an optional all argument. Translations will now fallback
351 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000352
Martin v. Löwis9668b932002-01-12 11:27:42 +0000353- distutils bdist commands now offer a --skip-build option.
354
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000355- warnings.warn now accepts a Warning instance as first argument.
356
Fred Drakefed7e852002-04-04 19:36:15 +0000357- The xml.sax.expatreader.ExpatParser class will no longer create
358 circular references by using itself as the locator that gets passed
359 to the content handler implementation. [SF bug #535474]
360
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000361- The email.Parser.Parser class now properly parses strings regardless
362 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
363 or CRLF). Also, the Header class's constructor default arguments
364 has changed slightly so that an explicit maxlinelen value is always
365 honored.
366
Tim Petersaf8446f2001-12-21 21:36:50 +0000367Tools/Demos
368
Fred Drake40813b12002-08-05 15:24:19 +0000369- IDLE supports the new encoding declarations (PEP 263); it can also
370 deal with legacy 8-bit files if they use the locale's encoding. It
371 allows non-ASCII strings in the interactive shell and executes them
372 in the locale's encoding.
Martin v. Löwis98ce7b72002-08-05 15:11:26 +0000373
Marc-André Lemburg46260092002-04-04 16:17:11 +0000374- freeze.py now produces binaries which can import shared modules,
375 unlike before when this failed due to missing symbol exports in
376 the generated binary.
377
Tim Petersaf8446f2001-12-21 21:36:50 +0000378Build
379
Tim Petersf47630f2002-08-01 02:34:51 +0000380- The public Python C API will generally be declared using PyAPI_FUNC
Neal Norwitz1389f3e2002-07-22 13:21:10 +0000381 and PyAPI_DATA macros, while Python extension module init functions
382 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
383 are deprecated.
384
Tim Petersc6a3ff62002-07-08 22:11:52 +0000385- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
386 get into infinite loops, when a new-style class got garbage-collected.
387 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
388 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
389 COUNT_ALLOCS is not enabled by default, in either release or debug
390 builds, and that new-style classes are immortal only in COUNT_ALLOCS
391 builds.
392
Tim Peters943382c2002-07-07 03:59:34 +0000393- Compiling out the cyclic garbage collector is no longer an option.
394 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
395 that it's always defined (for the benefit of any extension modules
396 that may be conditionalizing on it). A bonus is that any extension
397 type participating in cyclic gc can choose to participate in the
398 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
399 to require editing the core to teach the trashcan mechanism about the
400 new type.
401
Martin v. Löwis0cec0ff2002-07-28 16:33:45 +0000402- According to Annex F of the current C standard,
Tim Peters1de41bf2002-07-03 03:31:20 +0000403
404 The Standard C macro HUGE_VAL and its float and long double analogs,
405 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
406 positive infinities.
407
408 Python only uses the double HUGE_VAL, and only to #define its own symbol
409 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
410 pyport.h used to try to worm around that, but the workarounds triggered
411 other bugs on other platforms, so we gave up. If your platform defines
412 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
413 that works on your platform. The only instance of this I'm sure about
414 is on an unknown subset of Cray systems, described here:
415
416 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
417
418 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
419
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000420- The configure option --without-doc-strings can be used to remove the
421 doc strings from the builtin functions and modules; this reduces the
422 size of the executable.
423
Tim Peters639295f2002-04-21 07:30:30 +0000424- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
425 say how or when to configure it, or how to turn it off.
426
Martin v. Löwis1142de32002-03-29 16:28:31 +0000427- On Unix, a shared libpython2.3.so can be created with --enable-shared.
428
Tim Peters8deda702002-03-30 10:06:07 +0000429- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
430 preprocessor symbols were eliminated. The internal decisions they
431 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000432
Fred Drake7d28b732002-05-02 21:17:00 +0000433- The tools used to build the documentation now work under Cygwin as
434 well as Unix.
435
Skip Montanaro57454e52002-06-14 20:30:31 +0000436- The bsddb and dbm module builds have been changed to try and avoid version
437 skew problems and disable linkage with Berkeley DB 1.85 unless the
438 installer knows what s/he's doing. See the section on building these
439 modules in the README file for details.
440
Tim Petersaf8446f2001-12-21 21:36:50 +0000441C API
442
Marc-André Lemburgcc8764c2002-08-11 12:23:04 +0000443- New C API PyUnicode_FromOrdinal() which exposes unichr() at C
444 level.
445
Thomas Heller085358a2002-07-29 14:27:41 +0000446- New functions PyErr_SetExcFromWindowsErr() and
447 PyErr_SetExcFromWindowsErrWithFilename(). Similar to
448 PyErr_SetFromWindowsErrWithFilename() and
449 PyErr_SetFromWindowsErr(), but they allow to specify
450 the exception type to raise. Available on Windows.
451
Tim Peters7c321a82002-07-09 02:57:01 +0000452- Py_FatalError() is now declared as taking a const char* argument. It
453 was previously declared without const. This should not affect working
454 code.
455
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000456- Added new macro PySequence_ITEM(o, i) that directly calls
457 sq_item without rechecking that o is a sequence and without
458 adjusting for negative indices.
459
Fred Draked0ba6362002-05-02 21:28:26 +0000460- PyRange_New() now raises ValueError if the fourth argument is not 1.
461 This is part of the removal of deprecated features of the xrange
462 object.
463
Guido van Rossum517c7d42002-04-26 02:49:14 +0000464- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
465 coercion if both arguments have the same type but this type has the
466 CHECKTYPES flag set. This is to better support proxies.
467
Neil Schemenauer9344b142002-04-12 23:00:08 +0000468- The type of tp_free has been changed from "void (*)(PyObject *)" to
469 "void (*)(void *)".
470
471- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
472
Guido van Rossum0986d822002-04-08 01:38:42 +0000473- A type can now inherit its metatype from its base type. Previously,
474 when PyType_Ready() was called, if ob_type was found to be NULL, it
475 was always set to &PyType_Type; now it is set to base->ob_type,
476 where base is tp_base, defaulting to &PyObject_Type.
477
478- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
479
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000480- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000481
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000482- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000483 without going through the buffer API.
484
Martin v. Löwis7198a522002-01-01 19:59:11 +0000485- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
486
Tim Peters10a3bb52001-12-25 19:07:38 +0000487- An old #define of ANY as void has been removed from pyport.h. This
488 hasn't been used since Python's pre-ANSI days, and the #define has
489 been marked as obsolete since then. SF bug 495548 says it created
490 conflicts with other packages, so keeping it around wasn't harmless.
491
Tim Petersaf8446f2001-12-21 21:36:50 +0000492- Because Python's magic number scheme broke on January 1st, we decided
493 to stop Python development. Thanks for all the fish!
494
Tim Petersfb05db22002-03-11 00:24:00 +0000495- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000496 scheme to a new one. See Python/import.c for details.
497
Tim Petersaf8446f2001-12-21 21:36:50 +0000498New platforms
499
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000500- AtheOS is now supported.
501
Andrew MacIntyre161ad0e2002-08-04 07:25:58 +0000502- the EMX runtime environment on OS/2 is now supported.
503
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000504- GNU/Hurd is now supported.
505
Tim Petersaf8446f2001-12-21 21:36:50 +0000506Tests
507
508Windows
509
Tim Peters08e72952002-04-16 20:48:01 +0000510- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
511 of that has been fixed in the installer (disabled Wise's "delete in-
512 use files" uninstall option).
513
Guido van Rossum181e41a2002-04-06 00:23:25 +0000514- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
515
Tim Peters33187922002-04-04 20:02:04 +0000516- The installer now installs Start menu shortcuts under (the local
517 equivalent of) "All Users" when doing an Admin install.
518
Tim Petersfb05db22002-03-11 00:24:00 +0000519- file.truncate([newsize]) now works on Windows for all newsize values.
520 It used to fail if newsize didn't fit in 32 bits, reflecting a
521 limitation of MS _chsize (which is no longer used).
522
Tim Petersab034fa2002-02-01 11:27:43 +0000523- os.waitpid() is now implemented for Windows, and can be used to block
524 until a specified process exits. This is similar to, but not exactly
525 the same as, os.waitpid() on POSIX systems. If you're waiting for
526 a specific process whose pid was obtained from one of the spawn()
527 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000528 See the docs for details. The docs were changed to clarify that
529 spawn functions return, and waitpid requires, a process handle on
530 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000531
Tim Peters11bd9942002-02-01 00:52:29 +0000532- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000533 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000534 to a nasty problem: before 2.3, if you got a temp file on Windows, it
535 got wrapped in an object whose close() method first closed the
536 underlying file, then deleted the file. This usually worked fine.
537 However, the spawn family of functions on Windows create (at a low C
538 level) the same set of open files in the spawned process Q as were
539 open in the spawning process P. If a temp file f was among them, then
540 doing f.close() in P first closed P's C-level file handle on f, but Q's
541 C-level file handle on f remained open, so the attempt in P to delete f
542 blew up with a "Permission denied" error (Windows doesn't allow
543 deleting open files). This was surprising, subtle, and difficult to
544 work around.
545
546- The os module now exports all the symbolic constants usable with the
547 low-level os.open() on Windows: the new constants in 2.3 are
548 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
549 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
550 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
551 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
552 (so specify both if you want both; note that neither is useful unless
553 specified with O_CREAT too).
554
Tim Petersaf8446f2001-12-21 21:36:50 +0000555Mac
556
557
Tim Peters909c0912001-12-14 23:16:18 +0000558What's New in Python 2.2 final?
559Release date: 21-Dec-2001
560===============================
561
562Type/class unification and new-style classes
563
Barry Warsaw52acb492001-12-21 20:04:22 +0000564- pickle.py, cPickle: allow pickling instances of new-style classes
565 with a custom metaclass.
566
Tim Peters909c0912001-12-14 23:16:18 +0000567Core and builtins
568
Barry Warsaw52acb492001-12-21 20:04:22 +0000569- weakref proxy object: when comparing, unwrap both arguments if both
570 are proxies.
571
Tim Peters909c0912001-12-14 23:16:18 +0000572Extension modules
573
Barry Warsaw52acb492001-12-21 20:04:22 +0000574- binascii.b2a_base64(): fix a potential buffer overrun when encoding
575 very short strings.
576
577- cPickle: the obscure "fast" mode was suspected of causing stack
578 overflows on the Mac. Hopefully fixed this by setting the recursion
579 limit much smaller. If the limit is too low (it only affects
580 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
581 when compiling cPickle.c (or in pyconfig.h).
582
Tim Peters909c0912001-12-14 23:16:18 +0000583Library
584
Barry Warsaw52acb492001-12-21 20:04:22 +0000585- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
586 close or delete time).
587
588- rfc822.py: fixed a bug where the address '<>' was converted to None
589 instead of an empty string (also fixes the email.Utils module).
590
591- xmlrpclib.py: version 1.0.0; uses precision for doubles.
592
593- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000594 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000595
Tim Peters909c0912001-12-14 23:16:18 +0000596Tools/Demos
597
598Build
599
600C API
601
602New platforms
603
604Tests
605
606Windows
607
Barry Warsaw52acb492001-12-21 20:04:22 +0000608- distutils package: fixed broken Windows installers (bdist_wininst).
609
610- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
611 instances are deleted at process exit time.
612
613- socket.py: prevent mysterious warnings when socket instances are
614 deleted at process exit time.
615
616- posixmodule.c: fix a Windows crash with stat() of a filename ending
617 in backslash.
618
Tim Peters909c0912001-12-14 23:16:18 +0000619Mac
620
Barry Warsaw52acb492001-12-21 20:04:22 +0000621- The Carbon toolbox modules have been upgraded to Universal Headers
622 3.4, and experimental CoreGraphics and CarbonEvents modules have
623 been added. All only for framework-enabled MacOSX.
624
Tim Peters909c0912001-12-14 23:16:18 +0000625
Tim Peters6272dfd2001-12-13 19:34:00 +0000626What's New in Python 2.2c1?
627Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000628===========================
629
630Type/class unification and new-style classes
631
Barry Warsaw06557452001-12-14 20:47:12 +0000632- Guido's tutorial introduction to the new type/class features has
633 been extensively updated. See
634
635 http://www.python.org/2.2/descrintro.html
636
637 That remains the primary documentation in this area.
638
Guido van Rossum33bab012001-12-05 22:45:48 +0000639- Fixed a leak: instance variables declared with __slots__ were never
640 deleted!
641
Guido van Rossum4b800852001-12-03 00:54:52 +0000642- The "delete attribute" method of descriptor objects is called
643 __delete__, not __del__. In previous releases, it was mistakenly
644 called __del__, which created an unfortunate overloading condition
645 with finalizers. (The "get attribute" and "set attribute" methods
646 are still called __get__ and __set__, respectively.)
647
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000648- Some subtle issues with the super built-in were fixed:
649
650 (a) When super itself is subclassed, its __get__ method would still
651 return an instance of the base class (i.e., of super).
652
653 (b) super(C, C()).__class__ would return C rather than super. This
654 is confusing. To fix this, I decided to change the semantics of
655 super so that it only applies to code attributes, not to data
656 attributes. After all, overriding data attributes is not
657 supported anyway.
658
659 (c) The __get__ method didn't check whether the argument was an
660 instance of the type used in creation of the super instance.
661
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000662- Previously, hash() of an instance of a subclass of a mutable type
663 (list or dictionary) would return some value, rather than raising
664 TypeError. This has been fixed. Also, directly calling
665 dict.__hash__ and list.__hash__ now raises the same TypeError
666 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000667
Guido van Rossumd331cb52001-12-05 19:46:42 +0000668- New-style objects now support deleting their __dict__. This is for
669 all intents and purposes equivalent to assigning a brand new empty
670 dictionary, but saves space if the object is not used further.
671
Tim Petersb3c9af12001-11-17 00:21:57 +0000672Core and builtins
673
Tim Peters3caca232001-12-06 06:23:26 +0000674- -Qnew now works as documented in PEP 238: when -Qnew is passed on
675 the command line, all occurrences of "/" use true division instead
676 of classic division. See the PEP for details. Note that "all"
677 means all instances in library and 3rd-party modules, as well as in
678 your own code. As the PEP says, -Qnew is intended for use only in
679 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000680 Note that test_coercion.py in the standard Python test suite fails
681 under -Qnew; this is expected, and won't be repaired until true
682 division becomes the default (in the meantime, test_coercion is
683 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000684
Fred Drake6c01e252001-12-14 17:08:12 +0000685- complex() now only allows the first argument to be a string
686 argument, and raises TypeError if either the second arg is a string
687 or if the second arg is specified when the first is a string.
688
Tim Petersb3c9af12001-11-17 00:21:57 +0000689Extension modules
690
Martin v. Löwis560da622001-11-24 09:24:51 +0000691- gc.get_referents was renamed to gc.get_referrers.
692
Tim Petersb3c9af12001-11-17 00:21:57 +0000693Library
694
Tim Peters25059d32001-12-07 20:35:43 +0000695- Functions in the os.spawn() family now release the global interpreter
696 lock around calling the platform spawn. They should always have done
697 this, but did not before 2.2c1. Multithreaded programs calling
698 an os.spawn function with P_WAIT will no longer block all Python threads
699 until the spawned program completes. It's possible that some programs
700 relies on blocking, although more likely by accident than by design.
701
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000702- webbrowser defaults to netscape.exe on OS/2 now.
703
Martin v. Löwis652e1912001-11-25 14:50:56 +0000704- Tix.ResizeHandle exposes detach_widget, hide, and show.
705
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000706- The charset alias windows_1252 has been added.
707
Barry Warsaw06557452001-12-14 20:47:12 +0000708- types.StringTypes is a tuple containing the defined string types;
709 usually this will be (str, unicode), but if Python was compiled
710 without Unicode support it will be just (str,).
711
712- The pulldom and minidom modules were synchronized to PyXML.
713
Tim Petersb3c9af12001-11-17 00:21:57 +0000714Tools/Demos
715
Barry Warsaw06557452001-12-14 20:47:12 +0000716- A new script called Tools/scripts/google.py was added, which fires
717 off a search on Google.
718
Tim Petersb3c9af12001-11-17 00:21:57 +0000719Build
720
Barry Warsaw06557452001-12-14 20:47:12 +0000721- Note that release builds of Python should arrange to define the
722 preprocessor symbol NDEBUG on the command line (or equivalent).
723 In the 2.2 pre-release series we tried to define this by magic in
724 Python.h instead, but it proved to cause problems for extension
725 authors. The Unix, Windows and Mac builds now all define NDEBUG in
726 release builds via cmdline (or equivalent) instead. Ports to
727 other platforms should do likewise.
728
Jack Jansen1999ef42001-12-06 21:47:20 +0000729- It is no longer necessary to use --with-suffix when building on a
730 case-insensitive file system (such as Mac OS X HFS+). In the build
731 directory an extension is used, but not in the installed python.
732
Tim Petersb3c9af12001-11-17 00:21:57 +0000733C API
734
Tim Petersf582b822001-12-11 18:51:08 +0000735- New function PyDict_MergeFromSeq2() exposes the builtin dict
736 constructor's logic for updating a dictionary from an iterable object
737 producing key-value pairs.
738
Tim Peterscffed4b2001-11-29 03:26:37 +0000739- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000740 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000741 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
742 dump core in some bad cases. This has been repaired. As a result,
743 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
744 previously went unchallenged.
745
Tim Petersb3c9af12001-11-17 00:21:57 +0000746New platforms
747
748Tests
749
750Windows
751
752Mac
753
Jack Jansenffa260f2001-12-06 21:14:00 +0000754- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
755 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000756
Barry Warsaw06557452001-12-14 20:47:12 +0000757- Changed logic for finding python home in Mac OS X framework Pythons.
758 Now sys.executable points to the executable again, in stead of to
759 the shared library. The latter is used only for locating the python
760 home.
761
762
Tim Peters84362bc2001-10-19 17:55:30 +0000763What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000764Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000765===========================
766
767Type/class unification and new-style classes
768
Guido van Rossum3d27df02001-11-15 20:27:54 +0000769- Multiple inheritance mixing new-style and classic classes in the
770 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000771
772 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000773 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000774
775 The MRO (method resolution order) for each base class is respected
776 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000777 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000778 This needs to be documented.
779
Tim Petersa427a2b2001-10-29 22:25:45 +0000780- The new builtin dictionary() constructor, and dictionary type, have
781 been renamed to dict. This reflects a decade of common usage.
782
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000783- dict() now accepts an iterable object producing 2-sequences. For
784 example, dict(d.items()) == d for any dictionary d. The argument,
785 and the elements of the argument, can be any iterable objects.
786
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000787- New-style classes can now have a __del__ method, which is called
788 when the instance is deleted (just like for classic classes).
789
Guido van Rossum12d955c2001-10-26 14:56:06 +0000790- Assignment to object.__dict__ is now possible, for objects that are
791 instances of new-style classes that have a __dict__ (unless the base
792 class forbids it).
793
Guido van Rossumc8e56452001-10-22 00:43:43 +0000794- Methods of built-in types now properly check for keyword arguments
795 (formerly these were silently ignored). The only built-in methods
796 that take keyword arguments are __call__, __init__ and __new__.
797
Guido van Rossum86443212001-10-27 22:28:54 +0000798- The socket function has been converted to a type; see below.
799
Tim Peters84362bc2001-10-19 17:55:30 +0000800Core and builtins
801
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000802- Assignment to __debug__ raises SyntaxError at compile-time. This
803 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000804 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000805
Guido van Rossum12d955c2001-10-26 14:56:06 +0000806- Clarified the error messages for unsupported operands to an operator
807 (like 1 + '').
808
Tim Peters84362bc2001-10-19 17:55:30 +0000809Extension modules
810
Tim Peters5ebfd362001-11-13 23:11:19 +0000811- mmap has a new keyword argument, "access", allowing a uniform way for
812 both Windows and Unix users to create read-only, write-through and
813 copy-on-write memory mappings. This was previously possible only on
814 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000815 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000816 platforms. Thanks to Jay T Miller for repairing this!
817
Tim Peters169ded02001-11-03 19:57:21 +0000818- By default, the gc.garbage list now contains only those instances in
819 unreachable cycles that have __del__ methods; in 2.1 it contained all
820 instances in unreachable cycles. "Instances" here has been generalized
821 to include instances of both new-style and old-style classes.
822
Guido van Rossum12d955c2001-10-26 14:56:06 +0000823- The socket module defines a new method for socket objects,
824 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000825 send() until all data has been sent. Also, the socket function has
826 been converted to a subclassable type, like list and tuple (etc.)
827 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000828
829- Various bugfixes to the curses module. There is now a test suite
830 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000831
Guido van Rossum692adf12001-10-30 03:03:03 +0000832- binascii.b2a_base64 no longer places an arbitrary restriction of 57
833 bytes on its input.
834
Tim Peters84362bc2001-10-19 17:55:30 +0000835Library
836
Tim Peters5ebfd362001-11-13 23:11:19 +0000837- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000838 convenience function.
839
Tim Peters75335872001-11-03 19:35:43 +0000840- Symbolic group names in regular expressions must be unique. For
841 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
842 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000843 Python 2.2 detects this error at regexp compilation time;
844 previously, the error went undetected, and results were
845 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
846 pattern.subn() methods have been rewritten in C. Also, an
847 experimental function/method finditer() has been added, which works
848 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000849
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000850- Tix exposes more commands through the classes DirSelectBox,
851 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
852 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
853 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
854
Tim Peters98791af2001-10-23 01:59:54 +0000855- Traceback objects are now scanned by cyclic garbage collection, so
856 cycles created by casual use of sys.exc_info() no longer cause
857 permanent memory leaks (provided garbage collection is enabled).
858
Guido van Rossum49192142001-10-24 20:51:44 +0000859- os.extsep -- a new variable needed by the RISCOS support. It is the
860 separator used by extensions, and is '.' on all platforms except
861 RISCOS, where it is '/'. There is no need to use this variable
862 unless you have a masochistic desire to port your code to RISCOS.
863
Barry Warsaw012852b2001-11-16 16:17:27 +0000864- mimetypes.py has optional support for non-standard, but commonly
865 found types. guess_type() and guess_extension() now accept an
866 optional `strict' flag, defaulting to true, which controls whether
867 recognize non-standard types or not. A few non-standard types we
868 know about have been added. Also, when run as a script, there are
869 new -l and -e options.
870
871- statcache is now deprecated.
872
873- email.Utils.formatdate() now produces the preferred RFC 2822 style
874 dates with numeric timezones (it used to produce obsolete dates
875 hard coded to "GMT" timezone). An optional `localtime' flag is
876 added to produce dates in the local timezone, with daylight savings
877 time properly taken into account.
878
879- In pickle and cPickle, instead of masking errors in load() by
880 transforming them into SystemError, we let the original exception
881 propagate out. Also, implement support for __safe_for_unpickling__
882 in pickle, as it already was supported in cPickle.
883
Tim Peters84362bc2001-10-19 17:55:30 +0000884Tools/Demos
885
886Build
887
Barry Warsaw012852b2001-11-16 16:17:27 +0000888- The dbm module is built using libdb1 if available. The bsddb module
889 is built with libdb3 if available.
890
891- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
892
Tim Peters84362bc2001-10-19 17:55:30 +0000893C API
894
Tim Peters1fc240e2001-10-26 05:06:50 +0000895- New function PySequence_Fast_GET_SIZE() returns the size of a non-
896 NULL result from PySequence_Fast(), more quickly than calling
897 PySequence_Size().
898
Barry Warsaw012852b2001-11-16 16:17:27 +0000899- New argument unpacking function PyArg_UnpackTuple() added.
900
901- New functions PyObject_CallFunctionObjArgs() and
902 PyObject_CallMethodObjArgs() have been added to make it more
903 convenient and efficient to call functions and methods from C.
904
905- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
906 possible that this will propagate errors it didn't before.
907
908- New function PyObject_CheckReadBuffer(), which returns true if its
909 argument supports the single-segment readable buffer interface.
910
Tim Peters84362bc2001-10-19 17:55:30 +0000911New platforms
912
Guido van Rossum86443212001-10-27 22:28:54 +0000913- We've finally confirmed that this release builds on HP-UX 11.00,
914 *with* threads, and passes the test suite.
915
Tim Peters7a33d8b2001-11-05 02:51:07 +0000916- Thanks to a series of patches from Michael Muller, Python may build
917 again under OS/2 Visual Age C++.
918
Guido van Rossum49192142001-10-24 20:51:44 +0000919- Updated RISCOS port by Dietmar Schwertberger.
920
Tim Peters84362bc2001-10-19 17:55:30 +0000921Tests
922
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000923- Added a test script for the curses module. It isn't run automatically;
924 regrtest.py must be run with '-u curses' to enable it.
925
Tim Peters84362bc2001-10-19 17:55:30 +0000926Windows
927
Barry Warsaw012852b2001-11-16 16:17:27 +0000928Mac
929
930- PythonScript has been moved to unsupported and is slated to be
931 removed completely in the next release.
932
933- It should now be possible to build applets that work on both OS9 and
934 OSX.
935
936- The core is now linked with CoreServices not Carbon; as a side
937 result, default 8bit encoding on OSX is now ASCII.
938
939- Python should now build on OSX 10.1.1
940
Tim Peters84362bc2001-10-19 17:55:30 +0000941
Tim Petersabf925f2001-09-28 21:53:42 +0000942What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000943Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000944===========================
945
946Type/class unification and new-style classes
947
Guido van Rossum687ae002001-10-15 22:03:32 +0000948- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000949 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000950 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000951 remains: the __dict__ of a new-style class is a read-only proxy; you
952 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000953 __defined__ attribute of new-style types no longer exists, for lack
954 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000955 future a __cache__ may be resurrected with a similar function, if I
956 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000957
Tim Peters1c9ca872001-10-04 06:43:12 +0000958- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
959 always returned None, even when there was a class docstring).
960
961- doctest now finds and runs docstrings attached to new-style classes,
962 class methods, static methods, and properties.
963
Guido van Rossum9074ef62001-10-16 21:34:49 +0000964Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000965
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000966- A very subtle syntactical pitfall in list comprehensions was fixed.
967 For example: [a+b for a in 'abc', for b in 'def']. The comma in
968 this example is a mistake. Previously, this would silently let 'a'
969 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
970 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
971 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
972 Note that [a for a in <singleton>] is a convoluted way to say
973 [<singleton>] anyway, so it's not like any expressiveness is lost.
974
Guido van Rossum9074ef62001-10-16 21:34:49 +0000975- getattr(obj, name, default) now only catches AttributeError, as
976 documented, rather than returning the default value for all
977 exceptions (which could mask bugs in a __getattr__ hook, for
978 example).
979
Fred Drakecb7a6b52001-10-22 18:41:51 +0000980- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000981 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000982 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000983 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000984
Guido van Rossum1c486092001-10-19 02:05:35 +0000985- unicode(obj) now behaves more like str(obj), accepting arbitrary
986 objects, and calling a __unicode__ method if it exists.
987 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000988 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000989
Barry Warsawf6fb1712001-10-19 05:35:40 +0000990- isinstance() now allows any object as the first argument and a
991 class, a type or something with a __bases__ tuple attribute for the
992 second argument. The second argument may also be a tuple of a
993 class, type, or something with __bases__, in which case isinstance()
994 will return true if the first argument is an instance of any of the
995 things contained in the second argument tuple. E.g.
996
997 isinstance(x, (A, B))
998
999 returns true if x is an instance of A or B.
1000
Guido van Rossum9074ef62001-10-16 21:34:49 +00001001Extension modules
1002
1003- thread.start_new_thread() now returns the thread ID (previously None).
1004
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001005- binascii has now two quopri support functions, a2b_qp and b2a_qp.
1006
Guido van Rossumc524d952001-10-19 01:31:59 +00001007- readline now supports setting the startup_hook and the
1008 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +00001009
Guido van Rossumc524d952001-10-19 01:31:59 +00001010- os and posix supports chroot(), setgroups() and unsetenv() where
1011 available. The stat(), fstat(), statvfs() and fstatvfs() functions
1012 now return "pseudo-sequences" -- the various fields can now be
1013 accessed as attributes (e.g. os.stat("/").st_mtime) but for
1014 backwards compatibility they also behave as a fixed-length sequence.
1015 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +00001016 attributes.
1017
1018- time: localtime(), gmtime() and strptime() now return a
1019 pseudo-sequence similar to the os.stat() return value, with
1020 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +00001021
Guido van Rossum9074ef62001-10-16 21:34:49 +00001022- Decompression objects in the zlib module now accept an optional
1023 second parameter to decompress() that specifies the maximum amount
1024 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +00001025
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001026- optional SSL support in the socket module now exports OpenSSL
1027 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
1028 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +00001029 automatically seed its PRNG. Also, the keyfile and certfile
1030 arguments to socket.ssl() are now optional.
1031
1032- posixmodule (and by extension, the os module on POSIX platforms) now
1033 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +00001034
Guido van Rossum9074ef62001-10-16 21:34:49 +00001035Library
Guido van Rossum3c288632001-10-16 21:13:49 +00001036
Tim Peters7402f792001-10-02 03:53:41 +00001037- doctest now excludes functions and classes not defined by the module
1038 being tested, thanks to Tim Hochberg.
1039
Fred Drakecb7a6b52001-10-22 18:41:51 +00001040- HotShot, a new profiler implemented using a C-based callback, has
1041 been added. This substantially reduces the overhead of profiling,
1042 but it is still quite preliminary. Support modules and
1043 documentation will be added in upcoming releases (before 2.2 final).
1044
Guido van Rossumc4b09b42001-10-04 10:19:00 +00001045- profile now produces correct output in situations where an exception
1046 raised in Python is cleared by C code (e.g. hasattr()). This used
1047 to cause wrong output, including spurious claims of recursive
1048 functions and attribution of time spent to the wrong function.
1049
Tim Peters0a1fc4e2001-10-07 03:12:08 +00001050 The code and documentation for the derived OldProfile and HotProfile
1051 profiling classes was removed. The code hasn't worked for years (if
1052 you tried to use them, they raised exceptions). OldProfile
1053 intended to reproduce the behavior of the profiler Python used more
1054 than 7 years ago, and isn't interesting anymore. HotProfile intended
1055 to provide a faster profiler (but producing less information), and
1056 that's a worthy goal we intend to meet via a different approach (but
1057 without losing information).
1058
Tim Peterscce092d2001-10-09 05:31:56 +00001059- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +00001060 a much better system-specific calibration constant. The constant can
1061 now be specified in an instance constructor, or as a Profile class or
1062 instance variable, instead of by editing profile.py's source code.
1063 Calibration must still be done manually (see the docs for the profile
1064 module).
1065
1066 Note that Profile.calibrate() must be overriden by subclasses.
1067 Improving the accuracy required exploiting detailed knowledge of
1068 profiler internals; the earlier method abstracted away the details
1069 and measured a simplified model instead, but consequently computed
1070 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +00001071
Martin v. Löwis16dc7f42001-09-30 20:32:11 +00001072- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +00001073 which indicates whether output is intended for the header 'Q'
1074 encoding.
1075
Guido van Rossuma5343cc2001-10-18 18:02:07 +00001076- The SocketServer.ThreadingMixIn class now closes the request after
1077 finish_request() returns. (Not when it errors out though.)
1078
Barry Warsawf6fb1712001-10-19 05:35:40 +00001079- The nntplib module's NNTP.body() method has grown a `file' argument
1080 to allow saving the message body to a file.
1081
1082- The email package has added a class email.Parser.HeaderParser which
1083 only parses headers and does not recurse into the message's body.
1084 Also, the module/class MIMEAudio has been added for representing
1085 audio data (contributed by Anthony Baxter).
1086
1087- ftplib should be able to handle files > 2GB.
1088
1089- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1090 ON, and OFF.
1091
Fred Drakecb7a6b52001-10-22 18:41:51 +00001092- xml.dom.minidom NodeList objects now support the length attribute
1093 and item() method as required by the DOM specifications.
1094
Guido van Rossumed554f62001-10-02 23:15:37 +00001095Tools/Demos
1096
1097- Demo/dns was removed. It no longer serves any purpose; a package
1098 derived from it is now maintained by Anthony Baxter, see
1099 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001100
Barry Warsawf6fb1712001-10-19 05:35:40 +00001101- The freeze tool has been made more robust, and two new options have
1102 been added: -X and -E.
1103
Tim Petersabf925f2001-09-28 21:53:42 +00001104Build
1105
Barry Warsawf6fb1712001-10-19 05:35:40 +00001106- configure will use CXX in LINKCC if CXX is used to build main() and
1107 the system requires to link a C++ main using the C++ compiler.
1108
Tim Petersabf925f2001-09-28 21:53:42 +00001109C API
1110
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001111- The documentation for the tp_compare slot is updated to require that
1112 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1113 not correct. This is not yet enforced but will be enforced in
1114 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1115 "NotImplemented". Right now, -1 should be used for an error return.
1116
Tim Petersd38b1c72001-09-30 05:09:37 +00001117- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1118 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1119 as long) arguments.
1120
Guido van Rossum3c288632001-10-16 21:13:49 +00001121- PyThread_start_new_thread() now returns a long int giving the thread
1122 ID, if one can be calculated; it returns -1 for error, 0 if no
1123 thread ID is calculated (this is an incompatible change, but only
1124 the thread module used this API). This code has only really been
1125 tested on Linux and Windows; other platforms please beware (and
1126 report any bugs or strange behavior).
1127
Guido van Rossum1c486092001-10-19 02:05:35 +00001128- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1129 input.
1130
Tim Petersabf925f2001-09-28 21:53:42 +00001131New platforms
1132
1133Tests
1134
1135Windows
1136
Tim Peters04cf1d32001-10-09 22:39:40 +00001137- Installer: If you install IDLE, and don't disable file-extension
1138 registration, a new "Edit with IDLE" context (right-click) menu entry
1139 is created for .py and .pyw files.
1140
Tim Peters1ce3cf72001-10-01 17:58:40 +00001141- The signal module now supports SIGBREAK on Windows, thanks to Steven
1142 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1143 action remains to call Win32 ExitProcess(). This can be changed via
1144 signal.signal(). For example:
1145
1146 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1147 # (SIGINT) behavior.
1148 import signal
1149 signal.signal(signal.SIGBREAK,
1150 signal.default_int_handler)
1151
1152 try:
1153 while 1:
1154 pass
1155 except KeyboardInterrupt:
1156 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1157 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1158 # program without the possibility for any Python-level cleanup).
1159 print "Clean exit"
1160
Tim Petersabf925f2001-09-28 21:53:42 +00001161
Tim Petersb07352e2001-09-08 01:25:47 +00001162What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001163Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001164===========================
1165
Guido van Rossum808eea72001-09-25 04:15:41 +00001166Type/class unification and new-style classes
1167
1168- pydoc and inspect are now aware of new-style classes;
1169 e.g. help(list) at the interactive prompt now shows proper
1170 documentation for all operations on list objects.
1171
1172- Applications using Jim Fulton's ExtensionClass module can now safely
1173 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1174 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1175 examples also work again. It is hoped that Gtk and Boost also work
1176 with 2.2a4 and beyond. (If you can confirm this, please write
1177 webmaster@python.org; if there are still problems, please open a bug
1178 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001179
Tim Peters66c1a522001-09-24 21:17:50 +00001180- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001181 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001182 in the constructed property object. fget, fset and fdel weren't
1183 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1184 associate a docstring with a property.
1185
Guido van Rossum808eea72001-09-25 04:15:41 +00001186- Comparison overloading is now more completely implemented. For
1187 example, a str subclass instance can properly be compared to a str
1188 instance, and it can properly overload comparison. Ditto for most
1189 other built-in object types.
1190
1191- The repr() of new-style classes has changed; instead of <type
1192 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1193 *except* for built-in types, which are still rendered as <type
1194 'Foo'> (to avoid upsetting existing code that might parse or
1195 otherwise rely on repr() of certain type objects).
1196
1197- The repr() of new-style objects is now always <Foo object at XXX>;
1198 previously, it was sometimes <Foo instance at XXX>.
1199
1200- For new-style classes, what was previously called __getattr__ is now
1201 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001202 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001203 one in classic classes is defined which is called only if regular
1204 attribute access raises AttributeError; to catch *all* attribute
1205 access, you can use __getattribute__ (for new-style classes). If
1206 both are defined, __getattribute__ is called first, and if it raises
1207 AttributeError, __getattr__ is called.
1208
1209- The __class__ attribute of new-style objects can be assigned to.
1210 The new class must have the same C-level object layout as the old
1211 class.
1212
1213- The builtin file type can be subclassed now. In the usual pattern,
1214 "file" is the name of the builtin type, and file() is a new builtin
1215 constructor, with the same signature as the builtin open() function.
1216 file() is now the preferred way to open a file.
1217
1218- Previously, __new__ would only see sequential arguments passed to
1219 the type in a constructor call; __init__ would see both sequential
1220 and keyword arguments. This made no sense whatsoever any more, so
1221 now both __new__ and __init__ see all arguments.
1222
1223- Previously, hash() applied to an instance of a subclass of str or
1224 unicode always returned 0. This has been repaired.
1225
1226- Previously, an operation on an instance of a subclass of an
1227 immutable type (int, long, float, complex, tuple, str, unicode),
1228 where the subtype didn't override the operation (and so the
1229 operation was handled by the builtin type), could return that
1230 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001231 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001232 with the same value as s.
1233
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001234- Provisional support for pickling new-style objects has been added.
1235
Guido van Rossum808eea72001-09-25 04:15:41 +00001236Core
1237
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001238- file.writelines() now accepts any iterable object producing strings.
1239
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001240- PyUnicode_FromEncodedObject() now works very much like
1241 PyObject_Str(obj) in that it tries to use __str__/tp_str
1242 on the object if the object is not a string or buffer. This
1243 makes unicode() behave like str() when applied to non-string/buffer
1244 objects.
1245
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001246- PyFile_WriteObject now passes Unicode objects to the file's write
1247 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001248 of a print statement must support Unicode objects, i.e. they must
1249 at least convert them into ASCII strings.
1250
Guido van Rossum624c8af2001-09-18 15:21:04 +00001251- Thread scheduling on Solaris should be improved; it is no longer
1252 necessary to insert a small sleep at the start of a thread in order
1253 to let other runnable threads be scheduled.
1254
Tim Petersb07352e2001-09-08 01:25:47 +00001255Library
1256
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001257- StringIO.StringIO instances and cStringIO.StringIO instances support
1258 read character buffer compatible objects for their .write() methods.
1259 These objects are converted to strings and then handled as such
1260 by the instances.
1261
Barry Warsaw2f600732001-09-24 04:28:10 +00001262- The "email" package has been added. This is basically a port of the
1263 mimelib package <http://sf.net/projects/mimelib> with API changes
1264 and some implementations updated to use iterators and generators.
1265
Tim Peters8a9c2842001-09-22 21:30:22 +00001266- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1267 restores the ability of Tools/scripts/ndiff.py to start producing output
1268 before the entire comparison is complete.
1269
Barry Warsaw58b072d2001-09-22 04:44:21 +00001270- StringIO.StringIO instances and cStringIO.StringIO instances support
1271 iteration just like file objects (i.e. their .readline() method is
1272 called for each iteration until it returns an empty string).
1273
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001274- The codecs module has grown four new helper APIs to access
1275 builtin codecs: getencoder(), getdecoder(), getreader(),
1276 getwriter().
1277
Guido van Rossum624c8af2001-09-18 15:21:04 +00001278- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1279 simplifies writing XML RPC servers.
1280
Barry Warsaw647d5e82001-09-28 17:01:02 +00001281- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001282 after interpretation of symbolic links. On non-Unix systems, this
1283 is an alias for os.path.abspath().
1284
Tim Peters16a77ad2001-09-08 04:00:12 +00001285- operator.indexOf() (PySequence_Index() in the C API) now works with any
1286 iterable object.
1287
Guido van Rossum624c8af2001-09-18 15:21:04 +00001288- smtplib now supports various authentication and security features of
1289 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001290
Guido van Rossum624c8af2001-09-18 15:21:04 +00001291- hmac: a new module implementing keyed hashing for message
1292 authentication.
1293
1294- mimetypes now recognizes more extensions and file types. At the
1295 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001296
Guido van Rossum624c8af2001-09-18 15:21:04 +00001297- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001298 Python 2.2 bytecode generation. It has also been promoted from a
1299 Tool to a standard library package. (Tools/compiler still exists as
1300 a sample driver.)
1301
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001302Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001303
Tim Petersb07352e2001-09-08 01:25:47 +00001304Build
1305
Guido van Rossum624c8af2001-09-18 15:21:04 +00001306- Large file support (LFS) is now automatic when the platform supports
1307 it; no more manual configuration tweaks are needed. On Linux, at
1308 least, it's possible to have a system whose C library supports large
1309 files but whose kernel doesn't; in this case, large file support is
1310 still enabled but doesn't do you any good unless you upgrade your
1311 kernel or share your Python executable with another system whose
1312 kernel has large file support.
1313
1314- The configure script now supplies plausible defaults in a
1315 cross-compilation environment. This doesn't mean that the supplied
1316 values are always correct, or that cross-compilation now works
1317 flawlessly -- but it's a first step (and it shuts up most of
1318 autoconf's warnings about AC_TRY_RUN).
1319
1320- The Unix build is now a bit less chatty, courtesy of the parser
1321 generator. The build is completely silent (except for errors) when
1322 using "make -s", thanks to a -q option to setup.py.
1323
Tim Petersb07352e2001-09-08 01:25:47 +00001324C API
1325
Guido van Rossum624c8af2001-09-18 15:21:04 +00001326- The "structmember" API now supports some new flag bits to deny read
1327 and/or write access to attributes in restricted execution mode.
1328
Tim Petersb07352e2001-09-08 01:25:47 +00001329New platforms
1330
Guido van Rossum624c8af2001-09-18 15:21:04 +00001331- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1332 (http://familiar.handhelds.org).
1333
Tim Petersb07352e2001-09-08 01:25:47 +00001334Tests
1335
Tim Peters8a9c2842001-09-22 21:30:22 +00001336- The "classic" standard tests, which work by comparing stdout to
1337 an expected-output file under Lib/test/output/, no longer stop at
1338 the first mismatch. Instead the test is run to completion, and a
1339 variant of ndiff-style comparison is used to report all differences.
1340 This is much easier to understand than the previous style of reporting.
1341
1342- The unittest-based standard tests now use regrtest's test_main()
1343 convention, instead of running as a side-effect of merely being
1344 imported. This allows these tests to be run in more natural and
1345 flexible ways as unittests, outside the regrtest framework.
1346
1347- regrtest.py is much better integrated with unittest and doctest now,
1348 especially in regard to reporting errors.
1349
Tim Petersb07352e2001-09-08 01:25:47 +00001350Windows
1351
Guido van Rossum624c8af2001-09-18 15:21:04 +00001352- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001353 that support it (NTFS under Windows 2000). See "What's New in
1354 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001355
Tim Petersb07352e2001-09-08 01:25:47 +00001356
Tim Petersedc99312001-08-22 21:36:50 +00001357What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001358Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001359===========================
1360
1361Core
1362
Tim Peters9fffa3e2001-09-04 05:14:19 +00001363- Conversion of long to float now raises OverflowError if the long is too
1364 big to represent as a C double.
1365
Tim Peters32f453e2001-09-03 08:35:41 +00001366- The 3-argument builtin pow() no longer allows a third non-None argument
1367 if either of the first two arguments is a float, or if both are of
1368 integer types and the second argument is negative (in which latter case
1369 the arguments are converted to float, so this is really the same
1370 restriction).
1371
Tim Peters5d2b77c2001-09-03 05:47:38 +00001372- The builtin dir() now returns more information, and sometimes much
1373 more, generally naming all attributes of an object, and all attributes
1374 reachable from the object via its class, and from its class's base
1375 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1376 an empty list. In 2.2a3,
1377
1378 >>> dir([])
1379 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1380 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1381 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1382 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1383 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1384 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1385 'reverse', 'sort']
1386
1387 dir(module) continues to return only the module's attributes, though.
1388
Tim Petersbdee63f2001-09-02 03:40:59 +00001389- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001390 than raising OverflowError. This is a partial implementation of PEP
1391 237. You can use -Wdefault::OverflowWarning to enable a warning for
1392 this situation, and -Werror::OverflowWarning to revert to the old
1393 OverflowError exception.
1394
Guido van Rossum61c345f2001-09-04 03:26:15 +00001395- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001396 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001397 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1398 -Qold, meaning the / operator has its classic meaning and no
1399 warnings are issued. Using -Qwarn issues a run-time warning about
1400 all uses of classic division for int and long arguments; -Qwarnall
1401 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001402 (for use with fixdiv.py).
1403 [Note: the remainder of this paragraph (preserved below) became
1404 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1405 <obsolete>
1406 Using -Qnew is questionable; it turns on new division by default, but
1407 only in the __main__ module. You can usefully combine -Qwarn or
1408 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1409 warns about classic division everywhere else.
1410 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001411
Tim Petersbdee63f2001-09-02 03:40:59 +00001412- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001413 long, float, str, unicode, and tuple. (The types complex, list and
1414 dictionary can also be subclassed; this was introduced earlier.)
1415 Note that restrictions apply when subclassing immutable built-in
1416 types: you can only affect the value of the instance by overloading
1417 __new__. You can add mutable attributes, and the subclass instances
1418 will have a __dict__ attribute, but you cannot change the "value"
1419 (as implemented by the base class) of an immutable subclass instance
1420 once it is created.
1421
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001422- The dictionary constructor now takes an optional argument, a
1423 mapping-like object, and initializes the dictionary from its
1424 (key, value) pairs.
1425
Tim Petersbdee63f2001-09-02 03:40:59 +00001426- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001427 "cooperative super calls" in a multiple inheritance setting. For an
1428 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1429
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001430- A new built-in type, property, has been added. This enables the
1431 creation of "properties". These are attributes implemented by
1432 getter and setter functions (or only one of these for read-only or
1433 write-only attributes), without the need to override __getattr__.
1434 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001435
Tim Petersbdee63f2001-09-02 03:40:59 +00001436- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001437 liberalized, to allow leading zeroes. Examples of literals now
1438 legal that were SyntaxErrors before:
1439
1440 00.0 0e3 0100j 07.5 00000000000000000008.
1441
Tim Petersbdee63f2001-09-02 03:40:59 +00001442- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001443 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1444
Tim Petersedc99312001-08-22 21:36:50 +00001445Library
1446
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001447- telnetlib includes symbolic names for the options, and support for
1448 setting an option negotiation callback.
1449
Tim Petersa40c7932001-09-05 22:36:56 +00001450- The new C standard no longer requires that math libraries set errno to
1451 ERANGE on overflow. For platform libraries that exploit this new
1452 freedom, Python's overflow-checking was wholly broken. A new overflow-
1453 checking scheme attempts to repair that, but may not be reliable on all
1454 platforms (C doesn't seem to provide anything both useful and portable
1455 in this area anymore).
1456
Martin v. Löwis44f86962001-09-05 13:44:54 +00001457- Asynchronous timeout actions are available through the new class
1458 threading.Timer.
1459
Tim Peters78526162001-09-05 00:53:45 +00001460- math.log and math.log10 now return sensible results for even huge
1461 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1462
Tim Petersbdee63f2001-09-02 03:40:59 +00001463- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001464 currently held. See the docs for the imp module.
1465
Tim Petersbdee63f2001-09-02 03:40:59 +00001466- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001467 dumps containing ints written on platforms where Python ints are 8 bytes.
1468 When read on a box where Python ints are 4 bytes, such values are
1469 converted to Python longs.
1470
Tim Petersbdee63f2001-09-02 03:40:59 +00001471- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001472 code objects is no longer allowed. This plugs a security hole.
1473
Steve Purcell6091cd62001-09-06 16:05:17 +00001474- unittest.TestResult instances no longer store references to tracebacks
1475 generated by test failures. This prevents unexpected dangling references
1476 to objects that should be garbage collected between tests.
1477
Tim Petersedc99312001-08-22 21:36:50 +00001478Tools
1479
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001480- Tools/scripts/fixdiv.py has been added which can be used to fix
1481 division operators as per PEP 238.
1482
Tim Petersedc99312001-08-22 21:36:50 +00001483Build
1484
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001485- If you are an adventurous person using Mac OS X you may want to look at
1486 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1487 application, which can be used for experimenting with Carbon or Cocoa.
1488 Discussion of this on pythonmac-sig, please.
1489
Tim Peters7eea37e2001-09-04 22:08:56 +00001490C API
1491
1492- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001493
Tim Peters9fffa3e2001-09-04 05:14:19 +00001494- Note that PyLong_AsDouble can fail! This has always been true, but no
1495 callers checked for it. It's more likely to fail now, because overflow
1496 errors are properly detected now. The proper way to check:
1497
1498 double x = PyLong_AsDouble(some_long_object);
1499 if (x == -1.0 && PyErr_Occurred()) {
1500 /* The conversion failed. */
1501 }
1502
Tim Petersbdee63f2001-09-02 03:40:59 +00001503- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001504 compile but will not participate in GC. To upgrade an extension
1505 module:
1506
1507 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001508
Neil Schemenauer4042c692001-08-30 15:38:01 +00001509 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1510 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001511
Neil Schemenauer4042c692001-08-30 15:38:01 +00001512 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1513 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001514
Neil Schemenauer4042c692001-08-30 15:38:01 +00001515 - remove PyGC_HEAD_SIZE from object size calculations
1516
1517 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1518
Tim Petersbdee63f2001-09-02 03:40:59 +00001519- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001520 These can be used safely to construct string objects from a
1521 sprintf-style format string (similar to the format string supported
1522 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001523
Tim Petersedc99312001-08-22 21:36:50 +00001524New platforms
1525
Tim Petersb7da0902001-09-02 23:01:43 +00001526- Stephen Hansen contributed patches sufficient to get a clean compile
1527 under Borland C (Windows), but he reports problems running it and ran
1528 out of time to complete the port. Volunteers? Expect a MemoryError
1529 when importing the types module; this is probably shallow, and
1530 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001531
Tim Petersedc99312001-08-22 21:36:50 +00001532Tests
1533
1534Windows
1535
Tim Peters6e13a562001-09-06 00:32:15 +00001536- Large file support is now enabled on Win32 platforms as well as on
1537 Win64. This means that, for example, you can use f.tell() and f.seek()
1538 to manipulate files larger than 2 gigabytes (provided you have enough
1539 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001540 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1541 filesize limit, and large file support makes no difference there.
1542 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1543 NTFS has no practical limit on file size, and files of any size can be
1544 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001545
Tim Petersbdee63f2001-09-02 03:40:59 +00001546- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001547 points to command.com (patch from Brian Quinlan).
1548
Tim Petersedc99312001-08-22 21:36:50 +00001549
Tim Peters20f51a72001-07-21 02:31:40 +00001550What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001551Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001552===========================
1553
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001554Build
1555
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001556- Tim Peters developed a brand new Windows installer using Wise 8.1,
1557 generously donated to us by Wise Solutions.
1558
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001559- configure supports a new option --enable-unicode, with the values
1560 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1561 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001562
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001563- A new configure option --enable-framework builds a Mac OS X framework,
1564 which "make frameworkinstall" will install. This provides a starting
1565 point for more mac-like functionality, join pythonmac-sig@python.org
1566 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001567
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001568- The NeXT platform is no longer supported.
1569
1570- The `new' module is now statically linked.
1571
Tim Peters0afb6092001-08-15 06:06:44 +00001572Tools
1573
1574- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001575 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001576 the module docstring for details.
1577
Tim Peters20f51a72001-07-21 02:31:40 +00001578Tests
1579
Tim Peters5e824c32001-08-12 22:25:01 +00001580- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001581 platforms, allowing to give clearer test result output. regrtest
1582 also has optional --use/-u switch to run normally disabled tests
1583 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001584
Tim Peters20f51a72001-07-21 02:31:40 +00001585- Several new tests in the standard test suite, with special thanks to
1586 Nick Mathewson.
1587
1588Core
1589
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001590- The floor division operator // has been added as outlined in PEP
1591 238. The / operator still provides classic division (and will until
1592 Python 3.0) unless "from __future__ import division" is included, in
1593 which case the / operator will provide true division. The operator
1594 module provides truediv() and floordiv() functions. Augmented
1595 assignment variants are included, as are the equivalent overloadable
1596 methods and C API methods. See the PEP for a full discussion:
1597 <http://python.sf.net/peps/pep-0238.html>
1598
Tim Peters6cd6a822001-08-17 22:11:27 +00001599- Future statements are now effective in simulated interactive shells
1600 (like IDLE). This should "just work" by magic, but read Michael
1601 Hudson's "Future statements in simulated shells" PEP 264 for full
1602 details: <http://python.sf.net/peps/pep-0264.html>.
1603
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001604- The type/class unification (PEP 252-253) was integrated into the
1605 trunk and is not so tentative any more (the exact specification of
1606 some features is still tentative). A lot of work has done on fixing
1607 bugs and adding robustness and features (performance still has to
1608 come a long way).
1609
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001610- Warnings about a mismatch in the Python API during extension import
1611 now use the Python warning framework (which makes it possible to
1612 write filters for these warnings).
1613
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001614- A function's __dict__ (aka func_dict) will now always be a
1615 dictionary. It used to be possible to delete it or set it to None,
1616 but now both actions raise TypeErrors. It is still legal to set it
1617 to a dictionary object. Getting func.__dict__ before any attributes
1618 have been assigned now returns an empty dictionary instead of None.
1619
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001620- A new command line option, -E, was added which disables the use of
1621 all environment variables, or at least those that are specifically
1622 significant to Python. Usually those have a name starting with
1623 "PYTHON". This was used to fix a problem where the tests fail if
1624 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1625 older distribution.
1626
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001627Library
1628
Tim Peters5e824c32001-08-12 22:25:01 +00001629- New class Differ and new functions ndiff() and restore() in difflib.py.
1630 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001631 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001632
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001633- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1634 value using the minimal quoting required for the value; more
1635 reliable than using xml.sax.saxutils.escape() for attribute values.
1636
1637- Readline completion support for cmd.Cmd was added.
1638
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001639- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1640
1641- Added function threading.BoundedSemaphore()
1642
1643- Added Ka-Ping Yee's cgitb.py module.
1644
1645- The `new' module now exposes the CO_xxx flags.
1646
Martin v. Löwis560da622001-11-24 09:24:51 +00001647- The gc module offers the get_referents function.
1648
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001649New platforms
1650
1651C API
1652
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001653- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1654 which provide a cross-platform implementations for the
1655 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1656 the standard sprintf() and vsprintf() C lib APIs, these versions
1657 apply bounds checking on the used buffer which enhances protection
1658 against buffer overruns.
1659
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001660- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001661 and extensions using different Unicode widths is rendered next to
1662 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001663 will result in an ImportError. Unicode extensions writers must make
1664 sure to check the Unicode width compatibility in their extensions by
1665 using at least one of the mangled Unicode APIs in the extension.
1666
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001667- Two new flags METH_NOARGS and METH_O are available in method definition
1668 tables to simplify implementation of methods with no arguments and a
1669 single untyped argument. Calling such methods is more efficient than
1670 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1671 deprecated.
1672
Tim Petersc1731372001-08-04 08:12:36 +00001673Windows
1674
1675- "import module" now compiles module.pyw if it exists and nothing else
1676 relevant is found.
1677
Tim Peters20f51a72001-07-21 02:31:40 +00001678
Guido van Rossum55a78992001-07-17 17:22:32 +00001679What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001680Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001681===========================
1682
1683Core
Tim Petersa814db52001-05-14 07:05:58 +00001684
Tim Peters6d6c1a32001-08-02 04:15:00 +00001685- TENTATIVELY, a large amount of code implementing much of what's
1686 described in PEP 252 (Making Types Look More Like Classes) and PEP
1687 253 (Subtyping Built-in Types) was added. This will be released
1688 with Python 2.2a1. Documentation will be provided separately
1689 through http://www.python.org/2.2/. The purpose of releasing this
1690 with Python 2.2a1 is to test backwards compatibility. It is
1691 possible, though not likely, that a decision is made not to release
1692 this code as part of 2.2 final, if any serious backwards
1693 incompapatibilities are found during alpha testing that cannot be
1694 repaired.
1695
Guido van Rossum55a78992001-07-17 17:22:32 +00001696- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001697 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001698 more 'yield' statements. See PEP 255. Since this adds a new
1699 keyword to the language, this feature must be enabled by including a
1700 future statement: "from __future__ import generators" (see PEP 236).
1701 Generators will become a standard feature in a future release
1702 (probably 2.3). Without this future statement, 'yield' remains an
1703 ordinary identifier, but a warning is issued each time it is used.
1704 (These warnings currently don't conform to the warnings framework of
1705 PEP 230; we intend to fix this in 2.2a2.)
1706
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001707- The UTF-16 codec was modified to be more RFC compliant. It will now
1708 only remove BOM characters at the start of the string and then
1709 only if running in native mode (UTF-16-LE and -BE won't remove a
1710 leading BMO character).
1711
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001712- Strings now have a new method .decode() to complement the already
1713 existing .encode() method. These two methods provide direct access
1714 to the corresponding decoders and encoders of the registered codecs.
1715
1716 To enhance the usability of the .encode() method, the special
1717 casing of Unicode object return values was dropped (Unicode objects
1718 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001719
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001720 Both methods will now return whatever the codec in charge of the
1721 requested encoding returns as object, e.g. Unicode codecs will
1722 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1723 will return u"äöü"). This enables codec writer to create codecs
1724 for various simple to use conversions.
1725
1726 New codecs were added to demonstrate these new features (the .encode()
1727 and .decode() columns indicate the type of the returned objects):
1728
1729 Name | .encode() | .decode() | Description
1730 ----------------------------------------------------------------------
1731 uu | string | string | UU codec (e.g. for email)
1732 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001733 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001734 zlib | string | string | zlib compression
1735 hex | string | string | 2-byte hex codec
1736 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1737
Mark Hammond2a0af792001-05-14 03:09:36 +00001738- Some operating systems now support the concept of a default Unicode
1739 encoding for file system operations. Notably, Windows supports 'mbcs'
1740 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001741 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001742 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001743
1744 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001745 functions that return filenames (such as os.listdir()) to return Python
1746 string objects pre-encoded using the default file system encoding for
1747 the platform. As this encoding is likely to be different from Python's
1748 default encoding, converting this name to a Unicode object before passing
1749 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001750 would attempt to use its default encoding (generally ASCII) rather than
1751 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001752
Tim Petersa814db52001-05-14 07:05:58 +00001753 In general, this change simply removes surprises when working with
1754 Unicode and the file system, making these operations work as you expect,
1755 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001756 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001757
Tim Peters61dff2b2001-05-08 15:43:37 +00001758- Float (and complex) literals in source code were evaluated to full
1759 precision only when running from a .py file; the same code loaded from a
1760 .pyc (or .pyo) file could suffer numeric differences starting at about the
1761 12th significant decimal digit. For example, on a machine with IEEE-754
1762 floating arithmetic,
1763
1764 x = 9007199254740992.0
1765 print long(x)
1766
1767 printed 9007199254740992 if run directly from .py, but 9007199254740000
1768 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1769 str(float) instead of repr(float) when building code objects. marshal
1770 now uses repr(float) instead, which should reproduce floats to full
1771 machine precision (assuming the platform C float<->string I/O conversion
1772 functions are of good quality).
1773
1774 This may cause floating-point results to change in some cases, and
1775 usually for the better, but may also cause numerically unstable
1776 algorithms to break.
1777
Tim Peters2f228e72001-05-13 00:19:31 +00001778- The implementation of dicts suffers fewer collisions, which has speed
1779 benefits. However, the order in which dict entries appear in dict.keys(),
1780 dict.values() and dict.items() may differ from previous releases for a
1781 given dict. Nothing is defined about this order, so no program should
1782 rely on it. Nevertheless, it's easy to write test cases that rely on the
1783 order by accident, typically because of printing the str() or repr() of a
1784 dict to an "expected results" file. See Lib/test/test_support.py's new
1785 sortdict(dict) function for a simple way to display a dict in sorted
1786 order.
1787
Tim Peters7a3bfc32001-06-12 01:22:22 +00001788- Many other small changes to dicts were made, resulting in faster
1789 operation along the most common code paths.
1790
Guido van Rossum10315822001-05-01 20:54:30 +00001791- Dictionary objects now support the "in" operator: "x in dict" means
1792 the same as dict.has_key(x).
1793
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001794- The update() method of dictionaries now accepts generic mapping
1795 objects. Specifically the argument object must support the .keys()
1796 and __getitem__() methods. This allows you to say, for example,
1797 {}.update(UserDict())
1798
Guido van Rossum10315822001-05-01 20:54:30 +00001799- Iterators were added; this is a generalized way of providing values
1800 to a for loop. See PEP 234. There's a new built-in function iter()
1801 to return an iterator. There's a new protocol to get the next value
1802 from an iterator using the next() method (in Python) or the
1803 tp_iternext slot (in C). There's a new protocol to get iterators
1804 using the __iter__() method (in Python) or the tp_iter slot (in C).
1805 Iterating (i.e. a for loop) over a dictionary generates its keys.
1806 Iterating over a file generates its lines.
1807
Tim Petersf553f892001-05-01 20:45:31 +00001808- The following functions were generalized to work nicely with iterator
1809 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001810 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001811 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1812 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001813 join() method of strings
1814 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001815 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1816 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001817 right-hand side of assignment statements with multiple targets, such as
1818 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001819
Tim Petersd85e1022001-05-11 21:51:48 +00001820- Accessing module attributes is significantly faster (for example,
1821 random.random or os.path or yourPythonModule.yourAttribute).
1822
Tim Peterse63415e2001-05-08 04:38:29 +00001823- Comparing dictionary objects via == and != is faster, and now works even
1824 if the keys and values don't support comparisons other than ==.
1825
Tim Peters95bf9392001-05-10 08:32:44 +00001826- Comparing dictionaries in ways other than == and != is slower: there were
1827 insecurities in the dict comparison implementation that could cause Python
1828 to crash if the element comparison routines for the dict keys and/or
1829 values mutated the dicts. Making the code bulletproof slowed it down.
1830
Tim Peterseb28ef22001-06-02 05:27:19 +00001831- Collisions in dicts are resolved via a new approach, which can help
1832 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001833 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001834 faster now. Thanks to Christian Tismer for pointing out the cause and
1835 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001836
Tim Peters52e155e2001-06-16 05:42:57 +00001837- repr() is much faster for large containers (dict, list, tuple).
1838
1839
Tim Petersa814db52001-05-14 07:05:58 +00001840Library
1841
Fred Drake960fdf92001-07-20 18:38:26 +00001842- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1843 were added to the string module. These a locale-indenpendent
1844 constants, unlike letters, lowercase, and uppercase. These are now
1845 use in appropriate locations in the standard library.
1846
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001847- The flags used in dlopen calls can now be configured using
1848 sys.setdlopenflags and queried using sys.getdlopenflags.
1849
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001850- Fredrik Lundh's xmlrpclib is now a standard library module. This
1851 provides full client-side XML-RPC support. In addition,
1852 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1853 one asyncore-based). Thanks to Eric Raymond for the documentation.
1854
Guido van Rossum643d3912001-07-05 14:46:25 +00001855- The xrange() object is simplified: it no longer supports slicing,
1856 repetition, comparisons, efficient 'in' checking, the tolist()
1857 method, or the start, stop and step attributes. See PEP 260.
1858
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001859- A new function fnmatch.filter to filter lists of file names was added.
1860
Barry Warsawffd674d2001-05-22 16:00:10 +00001861- calendar.py uses month and day names based on the current locale.
1862
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001863- strop is now *really* obsolete (this was announced before with 1.6),
1864 and issues DeprecationWarning when used (except for the four items
1865 that are still imported into string.py).
1866
Tim Petersa814db52001-05-14 07:05:58 +00001867- Cookie.py now sorts key+value pairs by key in output strings.
1868
1869- pprint.isrecursive(object) didn't correctly identify recursive objects.
1870 Now it does.
1871
Tim Peters95b3f782001-05-14 18:39:41 +00001872- pprint functions now much faster for large containers (tuple, list, dict).
1873
Tim Peters7b9542a2001-06-10 23:40:19 +00001874- New 'q' and 'Q' format codes in the struct module, corresponding to C
1875 types "long long" and "unsigned long long" (on Windows, __int64). In
1876 native mode, these can be used only when the platform C compiler supports
1877 these types (when HAVE_LONG_LONG is #define'd by the Python config
1878 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001879 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1880 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001881
Guido van Rossum83213cc2001-06-12 16:48:52 +00001882- The site module installs a new built-in function 'help' that invokes
1883 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1884 it displays a message reminding the user to use 'help()' or
1885 'help(object)'.
1886
Tim Petersa814db52001-05-14 07:05:58 +00001887Tests
1888
1889- New test_mutants.py runs dict comparisons where the key and value
1890 comparison operators mutute the dicts randomly during comparison. This
1891 rapidly causes Python to crash under earlier releases (not for the faint
1892 of heart: it can also cause Win9x to freeze or reboot!).
1893
1894- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001895 pprint.isreadable() return sensible results. Also verifies that simple
1896 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001897
Tim Peters4324aa32001-05-28 22:30:08 +00001898C API
1899
1900- Removed the unused last_is_sticky argument from the internal
1901 _PyTuple_Resize(). If this affects you, you were cheating.
1902
1903
Guido van Rossum55a78992001-07-17 17:22:32 +00001904======================================================================
1905
1906
Guido van Rossumffe13be2001-04-16 18:46:45 +00001907What's New in Python 2.1 (final)?
1908=================================
1909
1910We only changed a few things since the last release candidate, all in
1911Python library code:
1912
1913- A bug in the locale module was fixed that affected locales which
1914 define no grouping for numeric formatting.
1915
1916- A few bugs in the weakref module's implementations of weak
1917 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1918 and the test suite was updated to check for these bugs.
1919
1920- An old bug in the os.path.walk() function (introduced in Python
1921 2.0!) was fixed: a non-existent file would cause an exception
1922 instead of being ignored.
1923
1924- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1925 PyChecker.
1926
1927
Guido van Rossum5b08f132001-04-16 02:05:23 +00001928What's New in Python 2.1c2?
1929===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001930
Guido van Rossum5b08f132001-04-16 02:05:23 +00001931A flurry of small changes, and one showstopper fixed in the nick of
1932time made it necessary to release another release candidate. The list
1933here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001934
Guido van Rossum5b08f132001-04-16 02:05:23 +00001935Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001936
Guido van Rossum5b08f132001-04-16 02:05:23 +00001937- Tim discovered a nasty bug in the dictionary code, caused by
1938 PyDict_Next() calling dict_resize(), and the GC code's use of
1939 PyDict_Next() violating an assumption in dict_items(). This was
1940 fixed with considerable amounts of band-aid, but the net effect is a
1941 saner and more robust implementation.
1942
1943- Made a bunch of symbols static that were accidentally global.
1944
1945Build and Ports
1946
1947- The setup.py script didn't check for a new enough version of zlib
1948 (1.1.3 is needed). Now it does.
1949
1950- Changed "make clean" target to also remove shared libraries.
1951
1952- Added a more general warning about the SGI Irix optimizer to README.
1953
1954Library
1955
1956- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1957 omitted the slash between host and file.html.
1958
1959- The mailbox module's _Mailbox class contained a completely broken
1960 and undocumented seek() method. Ripped it out.
1961
1962- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1963 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1964
1965- Fixed a few last-minute bugs in unittest.
1966
1967Extensions
1968
1969- Reverted the patch to the OpenSSL code in socketmodule.c to support
1970 RAND_status() and the EGD, and the subsequent patch that tried to
1971 fix it for pre-0.9.5 versions; the problem with the patch is that on
1972 some systems it issues a warning whenever socket is imported, and
1973 that's unacceptable.
1974
1975Tests
1976
1977- Fixed the pickle tests to work with "import test.test_pickle".
1978
1979- Tweaked test_locale.py to actually run the test Windows.
1980
1981- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1982 not "wb" (which is not a valid mode at all).
1983
1984- Fix pstats browser crashes. Import readline if it exists to make
1985 the user interface nicer.
1986
1987- Add "import thread" to the top of test modules that import the
1988 threading module (test_asynchat and test_threadedtempfile). This
1989 prevents test failures caused by a broken threading module resulting
1990 from a previously caught failed import.
1991
1992- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1993 needed on some platforms (e.g. Solaris 8) when the tests are run
1994 twice in succession.
1995
1996- Skip rather than fail test_sunaudiodev if no audio device is found.
1997
1998
1999What's New in Python 2.1c1?
2000===========================
2001
2002This list was significantly updated when 2.1c2 was released; the 2.1c1
2003release didn't mention most changes that were actually part of 2.1c1:
2004
2005Legal
2006
2007- Copyright was assigned to the Python Software Foundation (PSF) and a
2008 PSF license (very similar to the CNRI license) was added.
2009
2010- The CNRI copyright notice was updated to include 2001.
2011
2012Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00002013
Guido van Rossumc9932722001-04-12 02:31:27 +00002014- After a public outcry, assignment to __debug__ is no longer illegal;
2015 instead, a warning is issued. It will become illegal in 2.2.
2016
Guido van Rossum5b08f132001-04-16 02:05:23 +00002017- Fixed a core dump with "%#x" % 0, and changed the semantics so that
2018 "%#x" now always prepends "0x", even if the value is zero.
2019
2020- Fixed some nits in the bytecode compiler.
2021
2022- Fixed core dumps when calling certain kinds of non-functions.
2023
2024- Fixed various core dumps caused by reference count bugs.
2025
2026Build and Ports
2027
2028- Use INSTALL_SCRIPT to install script files.
2029
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002030- New port: SCO Unixware 7, by Billy G. Allie.
2031
Guido van Rossum5b08f132001-04-16 02:05:23 +00002032- Updated RISCOS port.
2033
2034- Updated BeOS port and notes.
2035
2036- Various other porting problems resolved.
2037
2038Library
2039
2040- The TERMIOS and SOCKET modules are now truly obsolete and
2041 unnecessary. Their symbols are incorporated in the termios and
2042 socket modules.
2043
2044- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
2045 better tests for pickling.
2046
2047- threading: make Condition.wait() robust against KeyboardInterrupt.
2048
2049- zipfile: add support to zipfile to support opening an archive
2050 represented by an open file rather than a file name. Fix bug where
2051 the archive was not properly closed. Fixed a bug in this bugfix
2052 where flush() was called for a read-only file.
2053
2054- imputil: added an uninstall() method to the ImportManager.
2055
2056- Canvas: fixed bugs in lower() and tkraise() methods.
2057
2058- SocketServer: API change (added overridable close_request() method)
2059 so that the TCP server can explicitly close the request.
2060
2061- pstats: Eric Raymond added a simple interactive statistics browser,
2062 invoked when the module is run as a script.
2063
2064- locale: fixed a problem in format().
2065
2066- webbrowser: made it work when the BROWSER environment variable has a
2067 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
2068 KDE 2. Fixed some other nits.
2069
2070- unittest: changes to allow using a different exception than
2071 AssertionError, and added a few more function aliases. Some other
2072 small changes.
2073
2074- urllib, urllib2: fixed redirect problems and a coupleof other nits.
2075
2076- asynchat: fixed a critical bug in asynchat that slipped through the
2077 2.1b2 release. Fixed another rare bug.
2078
2079- Fix some unqualified except: clauses (always a bad code example).
2080
2081XML
2082
2083- pyexpat: new API get_version_string().
2084
2085- Fixed some minidom bugs.
2086
2087Extensions
2088
2089- Fixed a core dump in _weakref. Removed the weakref.mapping()
2090 function (it adds nothing to the API).
2091
2092- Rationalized the use of header files in the readline module, to make
2093 it compile (albeit with some warnings) with the very recent readline
2094 4.2, without breaking for earlier versions.
2095
2096- Hopefully fixed a buffering problem in linuxaudiodev.
2097
2098- Attempted a fix to make the OpenSSL support in the socket module
2099 work again with pre-0.9.5 versions of OpenSSL.
2100
2101Tests
2102
2103- Added a test case for asynchat and asyncore.
2104
2105- Removed coupling between tests where one test failing could break
2106 another.
2107
2108Tools
2109
2110- Ping added an interactive help browser to pydoc, fixed some nits
2111 in the rest of the pydoc code, and added some features to his
2112 inspect module.
2113
2114- An updated python-mode.el version 4.1 which integrates Ken
2115 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2116 much nicer in XEmacs and Emacs. When stepping through your program
2117 with pdb, in either the shell window or the *Python* window, the
2118 source file and line will be tracked by an arrow. Very cool!
2119
2120- IDLE: syntax warnings in interactive mode are changed into errors.
2121
2122- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002123 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002124
2125- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002126
Barry Warsaw11e89c72001-04-11 20:37:57 +00002127
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002128What's New in Python 2.1 beta 2?
2129================================
2130
Guido van Rossum053ae352001-03-22 14:17:21 +00002131(Unlisted are many fixed bugs, more documentation, etc.)
2132
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002133Core language, builtins, and interpreter
2134
Guido van Rossum053ae352001-03-22 14:17:21 +00002135- The nested scopes work (enabled by "from __future__ import
2136 nested_scopes") is completed; in particular, the future now extends
2137 into code executed through exec, eval() and execfile(), and into the
2138 interactive interpreter.
2139
2140- When calling a base class method (e.g. BaseClass.__init__(self)),
2141 this is now allowed even if self is not strictly spoken a class
2142 instance (e.g. when using metaclasses or the Don Beaudry hook).
2143
2144- Slice objects are now comparable but not hashable; this prevents
2145 dict[:] from being accepted but meaningless.
2146
2147- Complex division is now calculated using less braindead algorithms.
2148 This doesn't change semantics except it's more likely to give useful
2149 results in extreme cases. Complex repr() now uses full precision
2150 like float repr().
2151
2152- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2153
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002154- It is illegal to assign to the name __debug__, which is set when the
2155 interpreter starts. It is effectively a compile-time constant.
2156
2157- A warning will be issued if a global statement for a variable
2158 follows a use or assignment of that variable.
2159
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002160Standard library
2161
Guido van Rossum053ae352001-03-22 14:17:21 +00002162- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2163 inspired by JUnit), is now part of the standard library. You now
2164 have a choice of two testing frameworks: unittest requires you to
2165 write testcases as separate code, doctest gathers them from
2166 docstrings. Both approaches have their advantages and
2167 disadvantages.
2168
2169- A new module Tix was added, which wraps the Tix extension library
2170 for Tk. With that module, it is not necessary to statically link
2171 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2172 require" command. See Demo/tix/.
2173
2174- tzparse.py is now obsolete.
2175
2176- In gzip.py, the seek() and tell() methods are removed -- they were
2177 non-functional anyway, and it's better if callers can test for their
2178 existence with hasattr().
2179
2180Python/C API
2181
2182- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2183 that's already in the dictionary during a PyDict_Next() iteration.
2184 This used to fail occasionally when a dictionary resize operation
2185 could be triggered that would rehash all the keys. All other
2186 modifications to the dictionary are still off-limits during a
2187 PyDict_Next() iteration!
2188
2189- New extended APIs related to passing compiler variables around.
2190
2191- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2192 implement isinstance() and issubclass().
2193
2194- Py_BuildValue() now has a "D" conversion to create a Python complex
2195 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002196
Fred Drake4e262a92001-03-22 18:26:47 +00002197- Extensions types which support weak references must now set the
2198 field allocated for the weak reference machinery to NULL themselves;
2199 this is done to avoid the cost of checking each object for having a
2200 weakly referencable type in PyObject_INIT(), since most types are
2201 not weakly referencable.
2202
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002203- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2204 free variables and cell variables to and from the frame's f_locals.
2205
2206- Variants of several functions defined in pythonrun.h have been added
2207 to support the nested_scopes future statement. The variants all end
2208 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2209 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2210 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002211 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002212
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002213Distutils
2214
2215- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2216 into the release tree.
2217
Tim Peters0e57abf2001-05-02 07:39:38 +00002218- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002219 (an uninstaller, more customization of the installer's display)
2220
2221- from Jack Jansen: added Mac-specific code to generate a dialog for
2222 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002223 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002224 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002225
2226- added 'platforms' and 'keywords' to the set of metadata that can be
2227 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002228
2229- applied patches from Jason Tishler to make the compiler class work with
2230 Cygwin.
2231
2232
Tim Peters2fe289a2001-03-01 22:19:38 +00002233What's New in Python 2.1 beta 1?
2234================================
Tim Petersd66595f2001-02-04 03:09:53 +00002235
2236Core language, builtins, and interpreter
2237
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002238- Following an outcry from the community about the amount of code
2239 broken by the nested scopes feature introduced in 2.1a2, we decided
2240 to make this feature optional, and to wait until Python 2.2 (or at
2241 least 6 months) to make it standard. The option can be enabled on a
2242 per-module basis by adding "from __future__ import nested_scopes" at
2243 the beginning of a module (before any other statements, but after
2244 comments and an optional docstring). See PEP 236 (Back to the
2245 __future__) for a description of the __future__ statement. PEP 227
2246 (Statically Nested Scopes) has been updated to reflect this change,
2247 and to clarify the semantics in a number of endcases.
2248
2249- The nested scopes code, when enabled, has been hardened, and most
2250 bugs and memory leaks in it have been fixed.
2251
2252- Compile-time warnings are now generated for a number of conditions
2253 that will break or change in meaning when nested scopes are enabled:
2254
2255 - Using "from...import *" or "exec" without in-clause in a function
2256 scope that also defines a lambda or nested function with one or
2257 more free (non-local) variables. The presence of the import* or
2258 bare exec makes it impossible for the compiler to determine the
2259 exact set of local variables in the outer scope, which makes it
2260 impossible to determine the bindings for free variables in the
2261 inner scope. To avoid the warning about import *, change it into
2262 an import of explicitly name object, or move the import* statement
2263 to the global scope; to avoid the warning about bare exec, use
2264 exec...in... (a good idea anyway -- there's a possibility that
2265 bare exec will be deprecated in the future).
2266
2267 - Use of a global variable in a nested scope with the same name as a
2268 local variable in a surrounding scope. This will change in
2269 meaning with nested scopes: the name in the inner scope will
2270 reference the variable in the outer scope rather than the global
2271 of the same name. To avoid the warning, either rename the outer
2272 variable, or use a global statement in the inner function.
2273
Neil Schemenauera35c6882001-02-27 04:45:05 +00002274- An optional object allocator has been included. This allocator is
2275 optimized for Python objects and should be faster and use less memory
2276 than the standard system allocator. It is not enabled by default
2277 because of possible thread safety problems. The allocator is only
2278 protected by the Python interpreter lock and it is possible that some
2279 extension modules require a thread safe allocator. The object
2280 allocator can be enabled by providing the "--with-pymalloc" option to
2281 configure.
2282
Tim Petersd66595f2001-02-04 03:09:53 +00002283Standard library
2284
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002285- pyexpat now detects the expat version if expat.h defines it. A
2286 number of additional handlers are provided, which are only available
2287 since expat 1.95. In addition, the methods SetParamEntityParsing and
2288 GetInputContext of Parser objects are available with 1.95.x
2289 only. Parser objects now provide the ordered_attributes and
2290 specified_attributes attributes. A new module expat.model was added,
2291 which offers a number of additional constants if 1.95.x is used.
2292
2293- xml.dom offers the new functions registerDOMImplementation and
2294 getDOMImplementation.
2295
2296- xml.dom.minidom offers a toprettyxml method. A number of DOM
2297 conformance issues have been resolved. In particular, Element now
2298 has an hasAttributes method, and the handling of namespaces was
2299 improved.
2300
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002301- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2302 getting information about live Python code, and pydoc.py, a module
2303 for interactively converting docstrings to HTML or text.
2304 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002305 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002306 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2307 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002308
Tim Peters1eff7962001-03-01 02:31:33 +00002309- New library module difflib.py, primarily packaging the SequenceMatcher
2310 class at the heart of the popular ndiff.py file-comparison tool.
2311
2312- doctest.py (a framework for verifying Python code examples in docstrings)
2313 is now part of the std library.
2314
Tim Petersd66595f2001-02-04 03:09:53 +00002315Windows changes
2316
Guido van Rossume3955a82001-03-02 14:05:59 +00002317- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2318 small GUI that lets you browse the module docstrings using your
2319 default web browser.
2320
Tim Peters1eff7962001-03-01 02:31:33 +00002321- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2322 Platforms) is implemented. See
2323
2324 http://python.sourceforge.net/peps/pep-0235.html
2325
2326 for full details, especially the "Current Lower-Left Semantics" section.
2327 The new Windows import rules are simpler than before:
2328
2329 A. If the PYTHONCASEOK environment variable exists, same as
2330 before: silently accept the first case-insensitive match of any
2331 kind; raise ImportError if none found.
2332
2333 B. Else search sys.path for the first case-sensitive match; raise
2334 ImportError if none found.
2335
2336 The same rules have been implented on other platforms with case-
2337 insensitive but case-preserving filesystems too (including Cygwin, and
2338 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002339
Tim Peters25a9ce32001-02-19 07:06:36 +00002340- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2341 what it's supposed to do (and does do under NT and 2000) via direct
2342 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002343 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002344 all Win9x systems before.
2345
Tim Peters1eff7962001-03-01 02:31:33 +00002346- Build: Subproject _test (effectively) renamed to _testcapi.
2347
Tim Peters2fe289a2001-03-01 22:19:38 +00002348New platforms
2349
2350- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2351 Thanks to Steven Majewski!
2352
2353- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2354 Tishler!
2355
Guido van Rossum9089b272001-03-02 06:49:50 +00002356- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2357 Schwertberger! See RISCOS/README for more information -- it seems
2358 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002359 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002360
Tim Peters25a9ce32001-02-19 07:06:36 +00002361
Tim Petersd7b5e882001-01-25 03:36:26 +00002362What's New in Python 2.1 alpha 2?
2363=================================
Tim Peters40ead762001-01-27 05:35:26 +00002364
Tim Petersd7b5e882001-01-25 03:36:26 +00002365Core language, builtins, and interpreter
2366
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002367- Scopes nest. If a name is used in a function or class, but is not
2368 local, the definition in the nearest enclosing function scope will
2369 be used. One consequence of this change is that lambda statements
2370 could reference variables in the namespaces where the lambda is
2371 defined. In some unusual cases, this change will break code.
2372
2373 In all previous version of Python, names were resolved in exactly
2374 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002375 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002376 function A is defined within a function B, the names bound in B are
2377 not visible in A. The new rules make names bound in B visible in A,
2378 unless A contains a name binding that hides the binding in B.
2379
2380 Section 4.1 of the reference manual describes the new scoping rules
2381 in detail. The test script in Lib/test/test_scope.py demonstrates
2382 some of the effects of the change.
2383
2384 The new rules will cause existing code to break if it defines nested
2385 functions where an outer function has local variables with the same
2386 name as globals or builtins used by the inner function. Example:
2387
2388 def munge(str):
2389 def helper(x):
2390 return str(x)
2391 if type(str) != type(''):
2392 str = helper(str)
2393 return str.strip()
2394
2395 Under the old rules, the name str in helper() is bound to the
2396 builtin function str(). Under the new rules, it will be bound to
2397 the argument named str and an error will occur when helper() is
2398 called.
2399
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002400- The compiler will report a SyntaxError if "from ... import *" occurs
2401 in a function or class scope. The language reference has documented
2402 that this case is illegal, but the compiler never checked for it.
2403 The recent introduction of nested scope makes the meaning of this
2404 form of name binding ambiguous. In a future release, the compiler
2405 may allow this form when there is no possibility of ambiguity.
2406
Tim Peters40ead762001-01-27 05:35:26 +00002407- repr(string) is easier to read, now using hex escapes instead of octal,
2408 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2409
2410 >>> "\texample \r\n" + chr(0) + chr(255)
2411 '\texample \r\n\x00\xff' # in 2.1
2412 '\011example \015\012\000\377' # in 2.0
2413
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002414- Functions are now compared and hashed by identity, not by value, since
2415 the func_code attribute is writable.
2416
Fred Drakefb9d7122001-02-01 20:00:40 +00002417- Weak references (PEP 205) have been added. This involves a few
2418 changes in the core, an extension module (_weakref), and a Python
2419 module (weakref). The weakref module is the public interface. It
2420 includes support for "explicit" weak references, proxy objects, and
2421 mappings with weakly held values.
2422
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002423- A 'continue' statement can now appear in a try block within the body
2424 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002425 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002426
Tim Petersd7b5e882001-01-25 03:36:26 +00002427Standard library
2428
Barry Warsaw30dbd142001-01-31 22:14:01 +00002429- mailbox.py now has a new class, PortableUnixMailbox which is
2430 identical to UnixMailbox but uses a more portable scheme for
2431 determining From_ separators. Also, the constructors for all the
2432 classes in this module have a new optional `factory' argument, which
2433 is a callable used when new message classes must be instantiated by
2434 the next() method.
2435
Tim Petersd7b5e882001-01-25 03:36:26 +00002436- random.py is now self-contained, and offers all the functionality of
2437 the now-deprecated whrandom.py. See the docs for details. random.py
2438 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002439 and restoring the internal state of the generator; and jumpahead(n),
2440 for quickly forcing the internal state to be the same as if n calls to
2441 random() had been made. The latter is particularly useful for multi-
2442 threaded programs, creating one instance of the random.Random() class for
2443 each thread, then using .jumpahead() to force each instance to use a
2444 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002445
Tim Peters0de88fc2001-02-01 04:59:18 +00002446- random.py's seed() function is new. For bit-for-bit compatibility with
2447 prior releases, use the whseed function instead. The new seed function
2448 addresses two problems: (1) The old function couldn't produce more than
2449 about 2**24 distinct internal states; the new one about 2**45 (the best
2450 that can be done in the Wichmann-Hill generator). (2) The old function
2451 sometimes produced identical internal states when passed distinct
2452 integers, and there was no simple way to predict when that would happen;
2453 the new one guarantees to produce distinct internal states for all
2454 arguments in [0, 27814431486576L).
2455
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002456- The socket module now supports raw packets on Linux. The socket
2457 family is AF_PACKET.
2458
Tim Peters9ea17ac2001-02-02 05:57:15 +00002459- test_capi.py is a start at running tests of the Python C API. The tests
2460 are implemented by the new Modules/_testmodule.c.
2461
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002462- A new extension module, _symtable, provides provisional access to the
2463 internal symbol table used by the Python compiler. A higher-level
2464 interface will be added on top of _symtable in a future release.
2465
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002466- Removed the obsolete soundex module.
2467
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002468- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2469 the isSameNode method; NamedNodeMap the get method.
2470
2471- xml.sax.expatreader supports the lexical handler property; it
2472 generates comment, startCDATA, and endCDATA events.
2473
Tim Petersee826f82001-01-31 19:39:44 +00002474Windows changes
2475
2476- Build procedure: the zlib project is built in a different way that
2477 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002478 the zlib binary used. See PCbuild\readme.txt for details. Your old
2479 zlib-related directories can be deleted; you'll need to download fresh
2480 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002481
Tim Peters9ea17ac2001-02-02 05:57:15 +00002482- Build: New subproject _test for the benefit of test_capi.py (see above).
2483
Tim Petersb16c56f2001-02-02 21:24:51 +00002484- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2485 interface to some Python compiler internals).
2486
2487- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002488 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002489
Tim Petersa3a3a032000-11-30 05:22:44 +00002490What's New in Python 2.1 alpha 1?
2491=================================
2492
2493Core language, builtins, and interpreter
2494
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002495- There is a new Unicode companion to the PyObject_Str() API
2496 called PyObject_Unicode(). It behaves in the same way as the
2497 former, but assures that the returned value is an Unicode object
2498 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002499
Guido van Rossumf98eda02001-01-17 15:54:45 +00002500- The comparison operators support "rich comparison overloading" (PEP
2501 207). C extension types can provide a rich comparison function in
2502 the new tp_richcompare slot in the type object. The cmp() function
2503 and the C function PyObject_Compare() first try the new rich
2504 comparison operators before trying the old 3-way comparison. There
2505 is also a new C API PyObject_RichCompare() (which also falls back on
2506 the old 3-way comparison, but does not constrain the outcome of the
2507 rich comparison to a Boolean result).
2508
2509 The rich comparison function takes two objects (at least one of
2510 which is guaranteed to have the type that provided the function) and
2511 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2512 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2513 object, which may be NotImplemented (in which case the tp_compare
2514 slot function is used as a fallback, if defined).
2515
2516 Classes can overload individual comparison operators by defining one
2517 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002518 __ge__. There are no explicit "reflected argument" versions of
2519 these; instead, __lt__ and __gt__ are each other's reflection,
2520 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2521 reflection (similar at the C level). No other implications are
2522 made; in particular, Python does not assume that == is the Boolean
2523 inverse of !=, or that < is the Boolean inverse of >=. This makes
2524 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002525
2526 Classes or types that want to implement (in)equality tests but not
2527 the ordering operators (i.e. unordered types) should implement ==
2528 and !=, and raise an error for the ordering operators.
2529
Guido van Rossuma88479f2001-01-18 14:28:08 +00002530 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002531 Boolean; e.g. a matrix type might want to return a matrix of bits
2532 for A < B, giving elementwise comparisons. Such types should ensure
2533 that any interpretation of their value in a Boolean context raises
2534 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2535 at the C level) to always raise an exception.
2536
Guido van Rossuma88479f2001-01-18 14:28:08 +00002537- Complex numbers use rich comparisons to define == and != but raise
2538 an exception for <, <=, > and >=. Unfortunately, this also means
2539 that cmp() of two complex numbers raises an exception when the two
2540 numbers differ. Since it is not mathematically meaningful to compare
2541 complex numbers except for equality, I hope that this doesn't break
2542 too much code.
2543
Tim Peters3389f192001-02-18 08:48:49 +00002544- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002545 not defined by the language, other than that it's arbitrary but
2546 consistent (see the Reference Manual). An implementation detail changed
2547 in 2.1a1 such that None now compares less than any other object. Code
2548 relying on this new behavior (like code that relied on the previous
2549 behavior) does so at its own risk.
2550
Barry Warsaw573b5412001-01-15 20:43:18 +00002551- Functions and methods now support getting and setting arbitrarily
2552 named attributes (PEP 232). Functions have a new __dict__
2553 (a.k.a. func_dict) which hold the function attributes. Methods get
2554 and set attributes on their underlying im_func. It is a TypeError
2555 to set an attribute on a bound method.
2556
Guido van Rossum051e3352001-01-15 19:11:10 +00002557- The xrange() object implementation has been improved so that
2558 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2559 limitation that in this case len(xrange(sys.maxint)) can't be
2560 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2561 work fine as long as the index i doesn't actually reach 2**31.
2562 (Python uses regular ints for sequence and string indices; fixing
2563 that is much more work.)
2564
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002565- Two changes to from...import:
2566
Guido van Rossumba381232001-02-03 15:06:40 +00002567 1) "from M import X" now works even if (after loading module M)
2568 sys.modules['M'] is not a real module; it's basically a getattr()
2569 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002570
2571 2) "from M import *" now looks for M.__all__ to decide which names to
2572 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2573 filters out names starting with '_' as before. Whether or not
2574 __all__ exists, there's no restriction on the type of M.
2575
Guido van Rossumf61f1662001-01-10 20:13:55 +00002576- File objects have a new method, xreadlines(). This is the fastest
2577 way to iterate over all lines in a file:
2578
2579 for line in file.xreadlines():
2580 ...do something to line...
2581
2582 See the xreadlines module (mentioned below) for how to do this for
2583 other file-like objects.
2584
2585- Even if you don't use file.xreadlines(), you may expect a speedup on
2586 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002587 quite a bit in platform-specific ways: on systems (like Linux) that
2588 support flockfile(), getc_unlocked(), and funlockfile(), those are
2589 used by default. On systems (like Windows) without getc_unlocked(),
2590 a complicated (but still thread-safe) method using fgets() is used by
2591 default.
2592
Tim Petersd52269b2001-01-25 06:23:18 +00002593 You can force use of the fgets() method by #define'ing
2594 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002595 getc_unlocked()).
2596
Tim Petersd52269b2001-01-25 06:23:18 +00002597 You can force fgets() not to be used by #define'ing
2598 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002599 test_bufio.py fails -- and let us know if it does!).
2600
2601- In addition, the fileinput module, while still slower than the other
2602 methods on most platforms, has been sped up too, by using
2603 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002604
2605- Support for run-time warnings has been added, including a new
2606 command line option (-W) to specify the disposition of warnings.
2607 See the description of the warnings module below.
2608
2609- Extensive changes have been made to the coercion code. This mostly
2610 affects extension modules (which can now implement mixed-type
2611 numerical operators without having to use coercion), but
2612 occasionally, in boundary cases the coercion semantics have changed
2613 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002614 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002615 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002616 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002617
Guido van Rossumf98eda02001-01-17 15:54:45 +00002618- In connection with the coercion changes, a new built-in singleton
2619 object, NotImplemented is defined. This can be returned for
2620 operations that wish to indicate they are not implemented for a
2621 particular combination of arguments. From C, this is
2622 Py_NotImplemented.
2623
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002624- The interpreter accepts now bytecode files on the command line even
2625 if they do not have a .pyc or .pyo extension. On Linux, after executing
2626
Martin v. Löwise214baa2001-02-04 22:37:56 +00002627import imp,sys,string
2628magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2629reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2630open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002631
2632 any byte code file can be used as an executable (i.e. as an argument
2633 to execve(2)).
2634
Tim Peters9940b802000-12-01 07:59:35 +00002635- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002636 character. In 1.6 and earlier, they never produced a sign,
2637 and raised an error if the value of the long was too large
2638 to fit in a Python int. In 2.0, they produced a sign if and
2639 only if too large to fit in an int. This was inconsistent
2640 across platforms (because the size of an int varies across
2641 platforms), and inconsistent with hex() and oct(). Example:
2642
2643 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002644 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002645 'ffffffbe' # in 2.0 and before, on 32-bit machines
2646 >>> hex(-0x42L)
2647 '-0x42L' # in all versions of Python
2648
Tim Peters9940b802000-12-01 07:59:35 +00002649 The behavior of %d formats for negative Python longs remains
2650 the same as in 2.0 (although in 1.6 and before, they raised
2651 an error if the long didn't fit in a Python int).
2652
2653 %u formats don't make sense for Python longs, but are allowed
2654 and treated the same as %d in 2.1. In 2.0, a negative long
2655 formatted via %u produced a sign if and only if too large to
2656 fit in an int. In 1.6 and earlier, a negative long formatted
2657 via %u raised an error if it was too big to fit in an int.
2658
Guido van Rossum3661d392000-12-12 22:10:31 +00002659- Dictionary objects have an odd new method, popitem(). This removes
2660 an arbitrary item from the dictionary and returns it (in the form of
2661 a (key, value) pair). This can be useful for algorithms that use a
2662 dictionary as a bag of "to do" items and repeatedly need to pick one
2663 item. Such algorithms normally end up running in quadratic time;
2664 using popitem() they can usually be made to run in linear time.
2665
Tim Peters36cdad12000-12-29 02:06:45 +00002666Standard library
2667
Thomas Woutersfe385252001-01-19 23:16:56 +00002668- In the time module, the time argument to the functions strftime,
2669 localtime, gmtime, asctime and ctime is now optional, defaulting to
2670 the current time (in the local timezone).
2671
Guido van Rossumda91f222001-01-15 16:36:08 +00002672- The ftplib module now defaults to passive mode, which is deemed a
2673 more useful default given that clients are often inside firewalls
2674 these days. Note that this could break if ftplib is used to connect
2675 to a *server* that is inside a firewall, from outside; this is
2676 expected to be a very rare situation. To fix that, you can call
2677 ftp.set_pasv(0).
2678
Martin v. Löwis10a27872001-01-13 09:54:41 +00002679- The module site now treats .pth files not only for path configuration,
2680 but also supports extensions to the initialization code: Lines starting
2681 with import are executed.
2682
Guido van Rossumf61f1662001-01-10 20:13:55 +00002683- There's a new module, warnings, which implements a mechanism for
2684 issuing and filtering warnings. There are some new built-in
2685 exceptions that serve as warning categories, and a new command line
2686 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2687 turns warnings into errors). warnings.warn(message[, category])
2688 issues a warning message; this can also be called from C as
2689 PyErr_Warn(category, message).
2690
2691- A new module xreadlines was added. This exports a single factory
2692 function, xreadlines(). The intention is that this code is the
2693 absolutely fastest way to iterate over all lines in an open
2694 file(-like) object:
2695
2696 import xreadlines
2697 for line in xreadlines.xreadlines(file):
2698 ...do something to line...
2699
2700 This is equivalent to the previous the speed record holder using
2701 file.readlines(sizehint). Note that if file is a real file object
2702 (as opposed to a file-like object), this is equivalent:
2703
2704 for line in file.xreadlines():
2705 ...do something to line...
2706
Tim Peters36cdad12000-12-29 02:06:45 +00002707- The bisect module has new functions bisect_left, insort_left,
2708 bisect_right and insort_right. The old names bisect and insort
2709 are now aliases for bisect_right and insort_right. XXX_right
2710 and XXX_left methods differ in what happens when the new element
2711 compares equal to one or more elements already in the list: the
2712 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002713 right. Code that doesn't care where equal elements end up should
2714 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002715
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002716- The new curses.panel module wraps the panel library that forms part
2717 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2718
Guido van Rossumf61f1662001-01-10 20:13:55 +00002719- The SocketServer module now sets the allow_reuse_address flag by
2720 default in the TCPServer class.
2721
2722- A new function, sys._getframe(), returns the stack frame pointer of
2723 the caller. This is intended only as a building block for
2724 higher-level mechanisms such as string interpolation.
2725
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002726- The pyexpat module supports a number of new handlers, which are
2727 available only in expat 1.2. If invocation of a callback fails, it
2728 will report an additional frame in the traceback. Parser objects
2729 participate now in garbage collection. If expat reports an unknown
2730 encoding, pyexpat will try to use a Python codec; that works only
2731 for single-byte charsets. The parser type objects is exposed as
2732 XMLParserObject.
2733
2734- xml.dom now offers standard definitions for symbolic node type and
2735 exception code constants, and a hierarchy of DOM exceptions. minidom
2736 was adjusted to use them.
2737
2738- The conformance of xml.dom.minidom to the DOM specification was
2739 improved. It detects a number of additional error cases; the
2740 previous/next relationship works even when the tree is modified;
2741 Node supports the normalize() method; NamedNodeMap, DocumentType and
2742 DOMImplementation classes were added; Element supports the
2743 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2744 method.
2745
Guido van Rossumf61f1662001-01-10 20:13:55 +00002746Build issues
2747
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002748- For Unix (and Unix-compatible) builds, configuration and building of
2749 extension modules is now greatly automated. Rather than having to
2750 edit the Modules/Setup file to indicate which modules should be
2751 built and where their include files and libraries are, a
2752 distutils-based setup.py script now takes care of building most
2753 extension modules. All extension modules built this way are built
2754 as shared libraries. Only a few modules that must be linked
2755 statically are still listed in the Setup file; you won't need to
2756 edit their configuration.
2757
2758- Python should now build out of the box on Cygwin. If it doesn't,
2759 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002760
2761- Python now always uses its own (renamed) implementation of getopt()
2762 -- there's too much variation among C library getopt()
2763 implementations.
2764
2765- C++ compilers are better supported; the CXX macro is always set to a
2766 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002767
Tim Petersd92dfe02000-12-12 01:18:41 +00002768Windows changes
2769
2770- select module: By default under Windows, a select() call
2771 can specify no more than 64 sockets. Python now boosts
2772 this Microsoft default to 512. If you need even more than
2773 that, see the MS docs (you'll need to #define FD_SETSIZE
2774 and recompile Python from source).
2775
Guido van Rossumf61f1662001-01-10 20:13:55 +00002776- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2777 subdirectory is no more!
2778
Tim Petersa3a3a032000-11-30 05:22:44 +00002779
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002780What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002781=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002782
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002783Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002784changes are in the file HISTORY. If you are making the jump directly
2785from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2786HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002787
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002788Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2789the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2790http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002791
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002792--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002793
2794======================================================================
2795
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002796What's new in 2.0 (since release candidate 1)?
2797==============================================
2798
2799Standard library
2800
2801- The copy_reg module was modified to clarify its intended use: to
2802 register pickle support for extension types, not for classes.
2803 pickle() will raise a TypeError if it is passed a class.
2804
2805- Fixed a bug in gettext's "normalize and expand" code that prevented
2806 it from finding an existing .mo file.
2807
2808- Restored support for HTTP/0.9 servers in httplib.
2809
Tim Peters989b7b92000-10-16 20:24:53 +00002810- The math module was changed to stop raising OverflowError in case of
2811 underflow, and return 0 instead in underflow cases. Whether Python
2812 used to raise OverflowError in case of underflow was platform-
2813 dependent (it did when the platform math library set errno to ERANGE
2814 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002815
2816- Fixed a bug in StringIO that occurred when the file position was not
2817 at the end of the file and write() was called with enough data to
2818 extend past the end of the file.
2819
2820- Fixed a bug that caused Tkinter error messages to get lost on
2821 Windows. The bug was fixed by replacing direct use of
2822 interp->result with Tcl_GetStringResult(interp).
2823
2824- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2825 redirect response.
2826
2827- Several changes were made to distutils: Some debugging code was
2828 removed from util. Fixed the installer used when an external zip
2829 program (like WinZip) is not found; the source code for this
2830 installer is in Misc/distutils. check_lib() was modified to behave
2831 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2832 test for whether installed modules are on sys.path was changed to
2833 use both normcase() and normpath().
2834
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002835- Several minor bugs were fixed in the xml package (the minidom,
2836 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002837
2838- The regression test driver (regrtest.py) behavior when invoked with
2839 -l changed: It now reports a count of objects that are recognized as
2840 garbage but not freed by the garbage collector.
2841
Tim Peters989b7b92000-10-16 20:24:53 +00002842- The regression test for the math module was changed to test
2843 exceptional behavior when the test is run in verbose mode. Python
2844 cannot yet guarantee consistent exception behavior across platforms,
2845 so the exception part of test_math is run only in verbose mode, and
2846 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002847
2848Internals
2849
2850- PyOS_CheckStack() has been disabled on Win64, where it caused
2851 test_sre to fail.
2852
2853Build issues
2854
2855- Changed compiler flags, so that gcc is always invoked with -Wall and
2856 -Wstrict-prototypes. Users compiling Python with GCC should see
2857 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002858 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002859 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002860
Tim Petersa3a3a032000-11-30 05:22:44 +00002861- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002862
2863Tools and other miscellany
2864
2865- The compiler in Tools/compiler was updated to support the new
2866 language features introduced in 2.0: extended print statement, list
2867 comprehensions, and augmented assignments. The new compiler should
2868 also be backwards compatible with Python 1.5.2; the compiler will
2869 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002870 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002871
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002872What's new in 2.0 release candidate 1 (since beta 2)?
2873=====================================================
2874
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002875What is release candidate 1?
2876
2877We believe that release candidate 1 will fix all known bugs that we
2878intend to fix for the 2.0 final release. This release should be a bit
2879more stable than the previous betas. We would like to see even more
2880widespread testing before the final release, so we are producing this
2881release candidate. The final release will be exactly the same unless
2882any show-stopping (or brown bag) bugs are found by testers of the
2883release candidate.
2884
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002885All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002886to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002887
2888Core language, builtins, and interpreter
2889
2890- A bug that caused crashes when __coerce__ was used with augmented
2891 assignment, e.g. +=, was fixed.
2892
2893- Raise ZeroDivisionError when raising zero to a negative number,
2894 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2895 power operator and the result of math.pow(0.0, -2.0) will vary by
2896 platform. On Linux, it raises a ValueError.
2897
2898- A bug in Unicode string interpolation was fixed that occasionally
2899 caused errors with formats including "%%". For example, the
2900 following expression "%% %s" % u"abc" no longer raises a TypeError.
2901
2902- Compilation of deeply nested expressions raises MemoryError instead
2903 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2904
2905- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2906 rendering them useless. They are now written in binary mode again.
2907
2908Standard library
2909
2910- Keyword arguments are now accepted for most pattern and match object
2911 methods in SRE, the standard regular expression engine.
2912
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002913- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002914 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002915
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002916- Several bugs in the Unicode handling and error handling in _tkinter
2917 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002918
2919- Fix memory management errors in Merge() and Tkapp_Call() routines.
2920
2921- Several changes were made to cStringIO to make it compatible with
2922 the file-like object interface and with StringIO. If operations are
2923 performed on a closed object, an exception is raised. The truncate
2924 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002925 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002926
2927- There were many changes made to the linuxaudiodev module and its
2928 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002929 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002930
2931 Note that this module is named poorly, because it should work
2932 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002933 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002934
2935 The module now raises exceptions when errors occur instead of
2936 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2937 audio) and defines a getptr() method that calls the
2938 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2939
2940- The library_version attribute, introduced in an earlier beta, was
2941 removed because it can not be supported with early versions of the C
2942 readline library, which provides no way to determine the version at
2943 compile-time.
2944
2945- The binascii module is now enabled on Win64.
2946
Tim Peters46446d62000-10-09 21:19:31 +00002947- tokenize.py no longer suffers "recursion depth" errors when parsing
2948 programs with very long string literals.
2949
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002950Internals
2951
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002952- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002953 which is called when the interpreter starts up to determine where
2954 the standard library is installed. These vulnerabilities affect all
2955 previous versions of Python and can be exploited by setting very
2956 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2957 setuid Python script, although use of the wrapper in
2958 Misc/setuid-prog.c will eliminate the vulnerability.
2959
2960- Fixed garbage collection bugs in instance creation that were
2961 triggered when errors occurred during initialization. The solution,
2962 applied in cPickle and in PyInstance_New(), is to call
2963 PyObject_GC_Init() after the initialization of the object's
2964 container attributes is complete.
2965
2966- pyexpat adds definitions of PyModule_AddStringConstant and
2967 PyModule_AddObject if the Python version is less than 2.0, which
2968 provides compatibility with PyXML on Python 1.5.2.
2969
2970- If the platform has a bogus definition for LONG_BIT (the number of
2971 bits in a long), an error will be reported at compile time.
2972
2973- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2974 collection crashes and possibly other, unreported crashes.
2975
2976- Fixed a memory leak in _PyUnicode_Fini().
2977
2978Build issues
2979
2980- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002981 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002982 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002983
2984- The mmap.PAGESIZE constant is now initialized using sysconf when
2985 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2986
2987- The md5 file should now compile on all platforms.
2988
2989- The select module now compiles on platforms that do not define
2990 POLLRDNORM and related constants.
2991
2992- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002993 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002994
Jeremy Hylton10921202000-10-09 18:34:12 +00002995- BeOS: A number of changes were made to the build and installation
2996 process. ar-fake now operates on a directory of object files.
2997 dl_export.h is gone, and its macros now appear on the mwcc command
2998 line during build on PPC BeOS.
2999
Jeremy Hyltond6e20232000-10-16 20:08:38 +00003000- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00003001 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00003002
3003- Cygwin: Support for shared libraries, Tkinter, and sockets.
3004
3005- SunOS 4.1.4_JL: Fix test for directory existence in configure.
3006
3007Tools and other miscellany
3008
3009- Removed debugging prints from main used with freeze.
3010
Tim Peters46446d62000-10-09 21:19:31 +00003011- IDLE auto-indent no longer crashes when it encounters Unicode
3012 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003013
3014What's new in 2.0 beta 2 (since beta 1)?
3015========================================
3016
3017Core language, builtins, and interpreter
3018
Tim Peters482c0212000-09-26 06:33:09 +00003019- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003020 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003021
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003022- Add -h and -V command line options to print the usage message and
3023 Python version number and exit immediately.
3024
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003025- eval() and exec accept Unicode objects as code parameters.
3026
3027- getattr() and setattr() now also accept Unicode objects for the
3028 attribute name, which are converted to strings using the default
3029 encoding before lookup.
3030
3031- Multiplication on string and Unicode now does proper bounds
3032 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
3033 string is too long."
3034
3035- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00003036 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003037
Jeremy Hylton1b618592000-09-26 05:32:36 +00003038
3039Standard library and extensions
3040
Guido van Rossum5b08f132001-04-16 02:05:23 +00003041- socket module: the OpenSSL code now adds support for RAND_status()
3042 and EGD (Entropy Gathering Device).
3043
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003044- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00003045 argument checking; it still takes no arguments.
3046
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003047- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003048
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003049- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003050
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003051- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003052
3053- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003054 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003055
3056- copy: Copy Unicode objects atomically.
3057
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003058- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003059
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003060- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003061
Fred Drake67233bc2000-09-26 16:40:27 +00003062- dbm: Add get() and setdefault() methods to dbm object. Add constant
3063 `library' to module that names the library used. Added doc strings
3064 and method names to error messages. Uses configure to determine
3065 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
3066 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003067
3068- distutils: Update to version 0.9.3.
3069
3070- dl: Add several dl.RTLD_ constants.
3071
3072- fpectl: Now supported on FreeBSD.
3073
3074- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
3075 found by the collector will be saved in gc.garbage. This is useful
3076 for debugging a program that creates reference cycles.
3077
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003078- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00003079 of HTTP class. Do not close socket on zero-length response. Do not
3080 crash when server sends invalid content-length header.
3081
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003082- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003083
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003084- marshal: When reading a short, sign-extend on platforms where shorts
3085 are bigger than 16 bits. When reading a long, repair the unportable
3086 sign extension that was being done for 64-bit machines. (It assumed
3087 that signed right shift sign-extends.)
3088
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003089- operator: Add contains(), invert(), __invert__() as aliases for
3090 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003091
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003092- os: Add support for popen2() and popen3() on all platforms where
3093 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003094
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003095- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003096 clicking on a file in Explorer (or passing the file name to the
3097 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003098
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003099- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003100 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003101
3102- pickle: Now raises ValueError when an invalid pickle that contains
3103 a non-string repr where a string repr was expected. This behavior
3104 matches cPickle.
3105
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003106- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003107
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003108- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003109
3110- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003111 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003112 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003113
3114- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003115 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003116
3117- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003118 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003119 few cycles during startup since the first call to
3120 setdefaultencoding() will initialize the codec registry and the
3121 encodings package.
3122
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003123- socket: Support for size hint in readlines() method of object returned
3124 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003125
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003126- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003127 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003128 is followed by whitespace.
3129
Tim Petersa3a3a032000-11-30 05:22:44 +00003130- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003131
3132- struct: Check ranges for bytes and shorts.
3133
3134- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003135 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003136
3137- Tkinter: Image objects are now guaranteed to have unique ids. Set
3138 event.delta to zero if Tk version doesn't support mousewheel.
3139 Removed some debugging prints.
3140
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003141- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003142
Fred Drake67233bc2000-09-26 16:40:27 +00003143- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003144 which works around a bug in Norton AntiVirus 2000 that leads directly
3145 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003146
3147- xml: New version detection code allows PyXML to override standard
3148 XML package if PyXML version is greater than 0.6.1.
3149
Fred Drake64bb3802000-09-26 16:21:35 +00003150- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3151 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3152 tree only for nodes which are sufficiently interesting to a specific
3153 application. Does not provide the HTML-specific extensions. Still
3154 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003155
Fred Drake64bb3802000-09-26 16:21:35 +00003156- xml.sax: SAX 2 support for Python, including all the handler
3157 interfaces needed to process XML 1.0 compliant XML. Some
3158 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003159
Fred Drake64bb3802000-09-26 16:21:35 +00003160- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3161 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003162
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003163
Jeremy Hylton1b618592000-09-26 05:32:36 +00003164C API
3165
3166- Add three new convenience functions for module initialization --
3167 PyModule_AddObject(), PyModule_AddIntConstant(), and
3168 PyModule_AddStringConstant().
3169
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003170- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003171 removed and add #error to Python.h if NULL isn't defined after
3172 #include of stdio.h.
3173
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003174- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003175 backwards compatibility (at the source level) with old extensions.
3176
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003177- A wrapper API was added for signal() and sigaction(). Instead of
3178 either function, always use PyOS_getsig() to get a signal handler
3179 and PyOS_setsig() to set one. A new convenience typedef
3180 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003181
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003182- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003183 internal data buffer and size of a string object -- or the default
3184 encoded version of a Unicode object.
3185
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003186- PyString_Size() and PyString_AsString() accept Unicode objects.
3187
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003188- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003189 exists). INT_MAX and LONG_MAX will always be defined, even if
3190 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003191
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003192- PyFloat_FromString takes a second argument, pend, that was
3193 effectively useless. It is now officially useless but preserved for
3194 backwards compatibility. If the pend argument is not NULL, *pend is
3195 set to NULL.
3196
3197- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3198 for the attribute name. See note on getattr() above.
3199
3200- A few bug fixes to argument processing for Unicode.
3201 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3202 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3203 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003204 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003205
3206- Py_BuildValue accepts B format (for bgen-generated code).
3207
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003208
Jeremy Hylton1b618592000-09-26 05:32:36 +00003209Internals
3210
3211- On Unix, fix code for finding Python installation directory so that
3212 it works when argv[0] is a relative path.
3213
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003214- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003215 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003216 rather than by generating a copy of the object.
3217
Tim Peters482c0212000-09-26 06:33:09 +00003218- Several of the internal Unicode tables are much smaller now, and
3219 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003220
Jeremy Hylton97693b02000-09-26 17:42:51 +00003221- In the garbage collector: Fixed bug in collection of tuples. Fixed
3222 bug that caused some instances to be removed from the container set
3223 while they were still live. Fixed parsing in gc.set_debug() for
3224 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003225
3226- Fixed refcount problem in instance deallocation that only occurred
3227 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3228
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003229- On Windows, getpythonregpath is now protected against null data in
3230 registry key.
3231
3232- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003233 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003234
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003235
Jeremy Hylton1b618592000-09-26 05:32:36 +00003236Build and platform-specific issues
3237
3238- Better support of GNU Pth via --with-pth configure option.
3239
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003240- Python/C API now properly exposed to dynamically-loaded extension
3241 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003242
3243- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3244 Don't define MS_SYNC to be zero when it is undefined. Added missing
3245 prototypes in posixmodule.c.
3246
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003247- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003248 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003249
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003250- Fix largefile support on older NetBSD systems and OpenBSD by adding
3251 define for TELL64.
3252
3253
3254Tools and other miscellany
3255
3256- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3257
3258- freeze: The modulefinder now works with 2.0 opcodes.
3259
Tim Petersa3a3a032000-11-30 05:22:44 +00003260- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003261 Move hackery of sys.argv until after the Tk instance has been
3262 created, which allows the application-specific Tkinter
3263 initialization to be executed if present; also pass an explicit
3264 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003265
Jeremy Hylton1b618592000-09-26 05:32:36 +00003266
3267What's new in 2.0 beta 1?
3268=========================
3269
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003270Source Incompatibilities
3271------------------------
3272
3273None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3274such as single-argument append(), connect() and bind(), and changes to
3275str(long) and repr(float).
3276
3277
3278Binary Incompatibilities
3279------------------------
3280
3281- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3282with Python 2.0; these extensions will have to be rebuilt for Python
32832.0.
3284
3285- On Windows, attempting to import a third party extension built for
3286Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3287can do about this. Check your PYTHONPATH environment variable!
3288
3289- Python bytecode files (*.pyc and *.pyo) are not compatible between
3290releases.
3291
3292
3293Overview of Changes Since 1.6
3294-----------------------------
3295
3296There are many new modules (including brand new XML support through
3297the xml package, and i18n support through the gettext module); a list
3298of all new modules is included below. Lots of bugs have been fixed.
3299
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003300The process for making major new changes to the language has changed
3301since Python 1.6. Enhancements must now be documented by a Python
3302Enhancement Proposal (PEP) before they can be accepted.
3303
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003304There are several important syntax enhancements, described in more
3305detail below:
3306
3307 - Augmented assignment, e.g. x += 1
3308
3309 - List comprehensions, e.g. [x**2 for x in range(10)]
3310
3311 - Extended import statement, e.g. import Module as Name
3312
3313 - Extended print statement, e.g. print >> file, "Hello"
3314
3315Other important changes:
3316
3317 - Optional collection of cyclical garbage
3318
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003319Python Enhancement Proposal (PEP)
3320---------------------------------
3321
3322PEP stands for Python Enhancement Proposal. A PEP is a design
3323document providing information to the Python community, or describing
3324a new feature for Python. The PEP should provide a concise technical
3325specification of the feature and a rationale for the feature.
3326
3327We intend PEPs to be the primary mechanisms for proposing new
3328features, for collecting community input on an issue, and for
3329documenting the design decisions that have gone into Python. The PEP
3330author is responsible for building consensus within the community and
3331documenting dissenting opinions.
3332
3333The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003334
3335Augmented Assignment
3336--------------------
3337
3338This must have been the most-requested feature of the past years!
3339Eleven new assignment operators were added:
3340
Guido van Rossume905e952000-09-05 12:42:46 +00003341 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003342
3343For example,
3344
3345 A += B
3346
3347is similar to
3348
3349 A = A + B
3350
3351except that A is evaluated only once (relevant when A is something
3352like dict[index].attr).
3353
3354However, if A is a mutable object, A may be modified in place. Thus,
3355if A is a number or a string, A += B has the same effect as A = A+B
3356(except A is only evaluated once); but if a is a list, A += B has the
3357same effect as A.extend(B)!
3358
3359Classes and built-in object types can override the new operators in
3360order to implement the in-place behavior; the not-in-place behavior is
3361used automatically as a fallback when an object doesn't implement the
3362in-place behavior. For classes, the method name is derived from the
3363method name for the corresponding not-in-place operator by inserting
3364an 'i' in front of the name, e.g. __iadd__ implements in-place
3365__add__.
3366
3367Augmented assignment was implemented by Thomas Wouters.
3368
3369
3370List Comprehensions
3371-------------------
3372
3373This is a flexible new notation for lists whose elements are computed
3374from another list (or lists). The simplest form is:
3375
3376 [<expression> for <variable> in <sequence>]
3377
Guido van Rossum56db0952000-09-06 23:34:25 +00003378For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003379This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003380
3381You can also add a condition:
3382
3383 [<expression> for <variable> in <sequence> if <condition>]
3384
3385For example, [w for w in words if w == w.lower()] would yield the list
3386of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003387than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003388
3389You can also have nested for loops and more than one 'if' clause. For
3390example, here's a function that flattens a sequence of sequences::
3391
3392 def flatten(seq):
3393 return [x for subseq in seq for x in subseq]
3394
3395 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3396
3397This prints
3398
3399 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3400
3401List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003402Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003403
3404
3405Extended Import Statement
3406-------------------------
3407
3408Many people have asked for a way to import a module under a different
3409name. This can be accomplished like this:
3410
3411 import foo
3412 bar = foo
3413 del foo
3414
3415but this common idiom gets old quickly. A simple extension of the
3416import statement now allows this to be written as follows:
3417
3418 import foo as bar
3419
3420There's also a variant for 'from ... import':
3421
3422 from foo import bar as spam
3423
3424This also works with packages; e.g. you can write this:
3425
3426 import test.regrtest as regrtest
3427
3428Note that 'as' is not a new keyword -- it is recognized only in this
3429context (this is only possible because the syntax for the import
3430statement doesn't involve expressions).
3431
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003432Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003433
3434
3435Extended Print Statement
3436------------------------
3437
3438Easily the most controversial new feature, this extension to the print
3439statement adds an option to make the output go to a different file
3440than the default sys.stdout.
3441
3442For example, to write an error message to sys.stderr, you can now
3443write:
3444
3445 print >> sys.stderr, "Error: bad dog!"
3446
3447As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003448evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003449
3450 print >> None, "Hello world"
3451
3452is equivalent to
3453
3454 print "Hello world"
3455
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003456Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003457
3458
3459Optional Collection of Cyclical Garbage
3460---------------------------------------
3461
3462Python is now equipped with a garbage collector that can hunt down
3463cyclical references between Python objects. It's no replacement for
3464reference counting; in fact, it depends on the reference counts being
3465correct, and decides that a set of objects belong to a cycle if all
3466their reference counts can be accounted for from their references to
3467each other. This devious scheme was first proposed by Eric Tiedemann,
3468and brought to implementation by Neil Schemenauer.
3469
3470There's a module "gc" that lets you control some parameters of the
3471garbage collection. There's also an option to the configure script
3472that lets you enable or disable the garbage collection. In 2.0b1,
3473it's on by default, so that we (hopefully) can collect decent user
3474experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003475performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003476off by default in the final 2.0 release.
3477
3478
3479Smaller Changes
3480---------------
3481
3482A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3483map(None, seq1, seq2, ...) when the sequences have the same length;
3484i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3485the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003486zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003487
3488sys.version_info is a tuple (major, minor, micro, level, serial).
3489
3490Dictionaries have an odd new method, setdefault(key, default).
3491dict.setdefault(key, default) returns dict[key] if it exists; if not,
3492it sets dict[key] to default and returns that value. Thus:
3493
3494 dict.setdefault(key, []).append(item)
3495
3496does the same work as this common idiom:
3497
3498 if not dict.has_key(key):
3499 dict[key] = []
3500 dict[key].append(item)
3501
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003502There are two new variants of SyntaxError that are raised for
3503indentation-related errors: IndentationError and TabError.
3504
3505Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3506escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003507
3508The limits on the size of expressions and file in Python source code
3509have been raised from 2**16 to 2**32. Previous versions of Python
3510were limited because the maximum argument size the Python VM accepted
3511was 2**16. This limited the size of object constructor expressions,
3512e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3513limit was raised thanks to a patch by Charles Waldman that effectively
3514fixes the problem. It is now much more likely that you will be
3515limited by available memory than by an arbitrary limit in Python.
3516
3517The interpreter's maximum recursion depth can be modified by Python
3518programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3519limit is the maximum number of recursive calls that can be made by
3520Python code. The limit exists to prevent infinite recursion from
3521overflowing the C stack and causing a core dump. The default value is
35221000. The maximum safe value for a particular platform can be found
3523by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003524
3525New Modules and Packages
3526------------------------
3527
3528atexit - for registering functions to be called when Python exits.
3529
3530imputil - Greg Stein's alternative API for writing custom import
3531hooks.
3532
3533pyexpat - an interface to the Expat XML parser, contributed by Paul
3534Prescod.
3535
3536xml - a new package with XML support code organized (so far) in three
3537subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3538would fill a volume. There's a special feature whereby a
3539user-installed package named _xmlplus overrides the standard
3540xmlpackage; this is intended to give the XML SIG a hook to distribute
3541backwards-compatible updates to the standard xml package.
3542
3543webbrowser - a platform-independent API to launch a web browser.
3544
3545
Guido van Rossume905e952000-09-05 12:42:46 +00003546Changed Modules
3547---------------
3548
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003549array -- new methods for array objects: count, extend, index, pop, and
3550remove
3551
3552binascii -- new functions b2a_hex and a2b_hex that convert between
3553binary data and its hex representation
3554
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003555calendar -- Many new functions that support features including control
3556over which day of the week is the first day, returning strings instead
3557of printing them. Also new symbolic constants for days of week,
3558e.g. MONDAY, ..., SUNDAY.
3559
3560cgi -- FieldStorage objects have a getvalue method that works like a
3561dictionary's get method and returns the value attribute of the object.
3562
3563ConfigParser -- The parser object has new methods has_option,
3564remove_section, remove_option, set, and write. They allow the module
3565to be used for writing config files as well as reading them.
3566
3567ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003568optionally support the RFC 959 REST command.
3569
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003570gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003571
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003572httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3573the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003574
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003575locale -- implement getdefaultlocale for Win32 and Macintosh
3576
3577marshal -- no longer dumps core when marshaling deeply nested or
3578recursive data structures
3579
3580os -- new functions isatty, seteuid, setegid, setreuid, setregid
3581
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003582os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3583support under Unix.
3584
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003585os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003586
3587os.path -- fix semantics of os.path.commonprefix
3588
3589smtplib -- support for sending very long messages
3590
3591socket -- new function getfqdn()
3592
3593readline -- new functions to read, write and truncate history files.
3594The readline section of the library reference manual contains an
3595example.
3596
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003597select -- add interface to poll system call
3598
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003599shutil -- new copyfileobj function
3600
3601SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3602HTTP server.
3603
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003604Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003605
3606urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003607e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003608
3609whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003610
3611
3612Obsolete Modules
3613----------------
3614
3615None. However note that 1.6 made a whole slew of modules obsolete:
3616stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3617poly, zmod, strop, util, whatsound.
3618
3619
3620Changed, New, Obsolete Tools
3621----------------------------
3622
Tim Peters8b092332000-09-05 20:15:25 +00003623None.
Guido van Rossume905e952000-09-05 12:42:46 +00003624
3625
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003626C-level Changes
3627---------------
3628
3629Several cleanup jobs were carried out throughout the source code.
3630
3631All C code was converted to ANSI C; we got rid of all uses of the
3632Py_PROTO() macro, which makes the header files a lot more readable.
3633
3634Most of the portability hacks were moved to a new header file,
3635pyport.h; several other new header files were added and some old
3636header files were removed, in an attempt to create a more rational set
3637of header files. (Few of these ever need to be included explicitly;
3638they are all included by Python.h.)
3639
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003640Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003641and Win64, especially for the new Intel Itanium processor. Mick also
3642added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003643
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003644The C APIs to return an object's size have been update to consistently
3645use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3646previous versions, the abstract interfaces used PyXXX_Length and the
3647concrete interfaces used PyXXX_Size. The old names,
3648e.g. PyObject_Length, are still available for backwards compatibility
3649at the API level, but are deprecated.
3650
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003651The PyOS_CheckStack function has been implemented on Windows by
3652Fredrik Lundh. It prevents Python from failing with a stack overflow
3653on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003654
3655The GC changes resulted in creation of two new slots on object,
3656tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003657the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003658
3659The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003660C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003661
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003662PyErr_Format has been updated to automatically calculate the size of
3663the buffer needed to hold the formatted result string. This change
3664prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003665
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003666New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003667
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003668PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3669that are the same as their non-Ex counterparts except they take an
3670extra flag argument that tells them to close the file when done.
3671
3672XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003673
Tim Peters8b092332000-09-05 20:15:25 +00003674
3675Windows Changes
3676---------------
3677
3678New popen2/popen3/peopen4 in os module (see Changed Modules above).
3679
3680os.popen is much more usable on Windows 95 and 98. See Microsoft
3681Knowledge Base article Q150956. The Win9x workaround described there
3682is implemented by the new w9xpopen.exe helper in the root of your
3683Python installation. Note that Python uses this internally; it is not
3684a standalone program.
3685
3686Administrator privileges are no longer required to install Python
3687on Windows NT or Windows 2000. If you have administrator privileges,
3688Python's registry info will be written under HKEY_LOCAL_MACHINE.
3689Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003690under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003691uses of Python, but will prevent some advanced uses from working
3692(for example, running a Python script as an NT service, or possibly
3693from CGI).
3694
3695[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3696installer; instead, it installs the needed Tcl/Tk files directly in the
3697Python directory. If you already have a Tcl/Tk installation, this
3698wastes some disk space (about 4 Megs) but avoids problems with
3699conflicting Tcl/Tk installations, and makes it much easier for Python
3700to ensure that Tcl/Tk can find all its files.
3701
3702[This was new in 1.6] The Windows installer now installs by default in
3703\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3704
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003705
3706Updates to the changes between 1.5.2 and 1.6
3707--------------------------------------------
3708
3709The 1.6 NEWS file can't be changed after the release is done, so here
3710is some late-breaking news:
3711
3712New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3713and changes to getlocale() and setlocale().
3714
3715The new module is now enabled per default.
3716
3717It is not true that the encodings codecs cannot be used for normal
3718strings: the string.encode() (which is also present on 8-bit strings
3719!) allows using them for 8-bit strings too, e.g. to convert files from
3720cp1252 (Windows) to latin-1 or vice-versa.
3721
3722Japanese codecs are available from Tamito KAJIYAMA:
3723http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3724
3725
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003726======================================================================