blob: 99d2d9095519e8d3dc7252868db4700c9bdd7266 [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
Mark Hammondc0e35152002-07-16 01:32:30 +00009- Ctrl+C handling on Windows has been made more consistent with
10 other platforms. KeyboardInterrupt can now reliably be caught,
11 and Ctrl+C at an interative prompt no longer terminates the
12 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
13 interrupt time.sleep() in the main thread, and any child processes
14 created via the popen family are also interrupted (as generally
15 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
16
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000017- Slices and repetitions of buffer objects now consistently return
18 a string. Formerly, strings would be returned most of the time,
19 but a buffer object would be returned when the repetition count
20 was one or when the slice range was all inclusive.
21
Guido van Rossumc7c36502002-06-21 01:29:25 +000022- The __slots__ variable can now mention "private" names, and the
23 right thing will happen (e.g. __slots__ = ["__foo"]).
24
Walter Dörwald3430d702002-06-17 10:43:59 +000025- Unicode objects in sys.path are no longer ignored but treated
26 as directory names.
27
Guido van Rossum9562bcf2002-06-14 21:31:18 +000028- The built-ins slice() and buffer() are now callable types. The
29 types classobj (formerly class), code, function, instance, and
30 instancemethod (formerly instance-method), which have no built-in
31 names but are accessible through the types module, are now also
32 callable. The type dict-proxy is renamed to dictproxy.
33
Neal Norwitz1f68fc72002-06-14 00:50:42 +000034- Fixed string.startswith and string.endswith builtin methods
35 so they accept negative indices. [SF bug 493951]
36
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000037- Fixed a bug with a continue inside a try block and a yield in the
38 finally clause. [SF bug 567538]
39
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000040- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000041 with a third "stride" parameter. For example, "hello world"[::-1]
42 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000043
Guido van Rossum9f7549b2002-06-10 21:39:42 +000044- Cycles going through the __class__ link of a new-style instance are
45 now detected by the garbage collector.
46
Guido van Rossum9923ffe2002-06-04 19:52:53 +000047- Classes using __slots__ are now properly garbage collected.
48 [SF bug 519621]
49
50- Tightened the __slots__ rules: a slot name must be a valid Python
51 identifier.
52
Guido van Rossum2e4e0262002-06-04 05:58:34 +000053- The constructor for the module type now requires a name argument and
54 takes an optional docstring argument. Previously, this constructor
55 ignored its arguments. As a consequence, deriving a class from a
56 module (not from the module type) is now illegal; previously this
57 created an unnamed module, just like invoking the module type did.
58 [SF bug 563060]
59
Neal Norwitzd68f5172002-05-29 15:54:55 +000060- A new warning PendingDeprecationWarning was added to provide
61 direction on features which are in the process of being deprecated.
62 The warning will not be printed by default. To see the pending
63 deprecations, use -Walways::PendingDeprecationWarning::
64 as a command line option or warnings.filterwarnings() in code.
65
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000066- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000067 for 'str' and 'unicode', and can be used instead of
68 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000069 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000070 is an abstract base class and cannot be instantiated directly.
71
Fred Draked0ba6362002-05-02 21:28:26 +000072- Deprecated features of xrange objects have been removed as
73 promised. The start, stop, and step attributes and the tolist()
74 method no longer exist. xrange repetition and slicing have been
75 removed.
76
Guido van Rossum7dab2422002-04-26 19:40:56 +000077- New builtin function enumerate(x), from PEP 279. Example:
78 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
79 The argument can be an arbitrary iterable object.
80
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000081- The assert statement no longer tests __debug__ at runtime. This means
82 that assert statements cannot be disabled by assigning a false value
83 to __debug__.
84
Walter Dörwald068325e2002-04-15 13:36:47 +000085- A method zfill() was added to str and unicode, that fills a numeric
86 string to the left with zeros. For example,
87 "+123".zfill(6) -> "+00123".
88
Guido van Rossum862fe3c2002-04-15 12:36:47 +000089- Complex numbers supported divmod() and the // and % operators, but
90 these make no sense. Since this was documented, they're being
91 deprecated now.
92
Guido van Rossum26dd8302002-04-26 20:11:29 +000093- String and unicode methods lstrip(), rstrip() and strip() now take
94 an optional argument that specifies the characters to strip. For
95 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000096
Guido van Rossumc69343b2002-04-12 19:22:48 +000097- Added a new dict method pop(key). This removes and returns the
98 value corresponding to key. [SF patch #539949]
99
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000100- Changed new-style class instantiation so that when C's __new__
101 method returns something that's not a C instance, its __init__ is
102 not called. [SF bug #537450]
103
Guido van Rossum181e41a2002-04-06 00:23:25 +0000104- Fixed super() to work correctly with class methods. [SF bug #535444]
105
Guido van Rossum47834462002-04-04 15:21:33 +0000106- A new built-in type, bool, has been added, as well as built-in
107 names for its two values, True and False. Comparisons and sundry
108 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000109 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000110 is backward compatible.
111
Guido van Rossum95b62a62002-03-29 01:07:24 +0000112- Fixed two bugs reported as SF #535905: under certain conditions,
113 deallocating a deeply nested structure could cause a segfault in the
114 garbage collector, due to interaction with the "trashcan" code;
115 access to the current frame during destruction of a local variable
116 could access a pointer to freed memory.
117
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000118- The optional object allocator ("pymalloc") has been enabled by
119 default. The recommended practice for memory allocation and
120 deallocation has been streamlined. A header file is included,
121 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
122 and lets them use the same API with Python versions from 1.5.2
123 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000124
Guido van Rossum8c842552002-03-14 23:05:54 +0000125- If you try to pickle an instance of a class that has __slots__ but
126 doesn't define or override __getstate__, a TypeError is now raised.
127 This is done by adding a bozo __getstate__ to the class that always
128 raises TypeError. (Before, this would appear to be pickled, but the
129 state of the slots would be lost.)
130
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000131- PyErr_Display will provide file and line information for all exceptions
132 that have an attribute print_file_and_line, not just SyntaxErrors.
133
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000134- The UTF-8 codec will now encode and decode Unicode surrogates
135 correctly and without raising exceptions for unpaired ones.
136
Neal Norwitz649b7592002-01-01 19:07:13 +0000137- file.xreadlines() now raises a ValueError if the file is closed:
138 Previously, an xreadlines object was returned which would raise
139 a ValueError when the xreadlines.next() method was called.
140
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000141- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000142 An exception will now be raised if more than one argument is used.
143
Tim Petersaf8446f2001-12-21 21:36:50 +0000144Extension modules
145
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000146- The 'new' module is no longer an extension, but a Python module that
147 only exists for backwards compatibility. Its contents are no longer
148 functions but callable type objects.
149
Tim Peters81b92512002-04-29 01:37:32 +0000150- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000151 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000152 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000153
Martin v. Löwis606edc12002-06-13 21:09:11 +0000154- posix.killpg, posix.mknod, and posix.getpgid have been added where
155 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000156
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000157- The locale module now exposes the C library's gettext interface.
158
Tim Petersfbf74f22002-03-14 19:06:01 +0000159- A security hole ("double free") was found in zlib-1.1.3, a popular
160 third party compression library used by some Python modules. The
161 hole was quickly plugged in zlib-1.1.4, and the Windows build of
162 Python now ships with zlib-1.1.4.
163
Martin v. Löwis688357e2002-04-08 21:28:20 +0000164- pwd, grp, and resource return enhanced tuples now, with symbolic
165 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000166
Martin v. Löwis99866332002-03-01 10:27:01 +0000167- array.array is now a type object. A new format character
168 'u' indicates Py_UNICODE arrays. For those, .tounicode and
169 .fromunicode methods are available. Arrays now support __iadd__
170 and __imul__.
171
Neal Norwitze790eae2002-01-01 21:14:12 +0000172- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000173 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
174 is called.
175
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000176- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
177 been added where available.
178
Tim Petersaf8446f2001-12-21 21:36:50 +0000179Library
180
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000181- New encoding for the Palm OS character set: palmos.
182
Tim Peters943382c2002-07-07 03:59:34 +0000183- binascii.crc32() and the zipfile module had problems on some 64-bit
184 platforms. These have been fixed. On a platform with 8-byte C longs,
185 crc32() now returns a signed-extended 4-byte result, so that its value
186 as a Python int is equal to the value computed a 32-bit platform.
187
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000188- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
189 argument.
190
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000191- Some fixes in the copy module: when an object is copied through its
192 __reduce__ method, there was no check for a __setstate__ method on
193 the result [SF patch 565085]; deepcopy should treat instances of
194 custom metaclasses the same way it treats instances of type 'type'
195 [SF patch 560794].
196
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000197- Sockets now support timeout mode. After s.settimeout(T), where T is
198 a float expressing seconds, subsequent operations raise an exception
199 if they cannot be completed within T seconds. To disable timeout
200 mode, use s.settimeout(None).
201
202- getopt.gnu_getopt was added. This supports GNU-style option
203 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000204
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000205- Stop using strings for exceptions. String objects used for
206 exceptions are now classes deriving from Exception. The objects
207 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
208 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000209
Walter Dörwald474458d2002-06-04 15:16:29 +0000210- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
211 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
212 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
213 big endian systems were added to the codecs module. The old names
214 BOM32_* and BOM64_* were off by a factor of 2.
215
Guido van Rossumf9257822002-06-18 20:43:18 +0000216- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000217
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000218- ftplib.retrlines() now tests for callback is None rather than testing
219 for False. Was causing an error when given a callback object which
220 was callable but also returned len() as zero. The change may
221 create new breakage if the caller relied on the undocumented behavior
222 and called with callback set to [] or some other False value not
223 identical to None.
224
Tim Peters46c04e12002-05-05 20:40:00 +0000225- random.gauss() uses a piece of hidden state used by nothing else,
226 and the .seed() and .whseed() methods failed to reset it. In other
227 words, setting the seed didn't completely determine the sequence of
228 results produced by random.gauss(). It does now. Programs repeatedly
229 mixing calls to a seed method with calls to gauss() may see different
230 results now.
231
Fred Drake7f781c92002-05-01 20:33:53 +0000232- The pickle.Pickler class grew a clear_memo() method to mimic that
233 provided by cPickle.Pickler.
234
Tim Peters81b92512002-04-29 01:37:32 +0000235- difflib's SequenceMatcher class now does a dynamic analysis of
236 which elements are so frequent as to constitute noise. For
237 comparing files as sequences of lines, this generally works better
238 than the IS_LINE_JUNK function, and function ndiff's linejunk
239 argument defaults to None now as a result. A happy benefit is
240 that SequenceMatcher may run much faster now when applied
241 to large files with many duplicate lines (for example, C program
242 text with lots of repeated "}" and "return NULL;" lines).
243
Guido van Rossum256705b2002-04-23 13:29:43 +0000244- New Text.dump() method in Tkinter module.
245
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000246- New distutils commands for building packagers were added to
247 support pkgtool on Solaris and swinstall on HP-UX.
248
249- distutils now has a new abstract binary packager base class
250 command/bdist_packager, which simplifies writing packagers.
251 This will hopefully provide the missing bits to encourage
252 people to submit more packagers, e.g. for Debian, FreeBSD
253 and other systems.
254
Guido van Rossumf9257822002-06-18 20:43:18 +0000255- The UTF-16, -LE and -BE stream readers now raise a
256 NotImplementedError for all calls to .readline(). Previously, they
257 used to just produce garbage or fail with an encoding error --
258 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 +0000259 work well with these.
260
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000261- compileall now supports quiet operation.
262
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000263- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000264 connections.
265
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000266- socket module: the SSL support was broken out of the main
267 _socket module C helper and placed into a new _ssl helper
268 which now gets imported by socket.py if available and working.
269
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000270- encodings package: added aliases for all supported IANA character
271 sets
272
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000273- ftplib: to safeguard the user's privacy, anonymous login will use
274 "anonymous@" as default password, rather than the real user and host
275 name.
276
Fred Drake36736122002-01-10 13:50:31 +0000277- webbrowser: tightened up the command passed to os.system() so that
278 arbitrary shell code can't be executed because a bogus URL was
279 passed in.
280
Tim Peters11bd9942002-02-01 00:52:29 +0000281- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000282 gettext.find an optional all argument. Translations will now fallback
283 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000284
Martin v. Löwis9668b932002-01-12 11:27:42 +0000285- distutils bdist commands now offer a --skip-build option.
286
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000287- warnings.warn now accepts a Warning instance as first argument.
288
Fred Drakefed7e852002-04-04 19:36:15 +0000289- The xml.sax.expatreader.ExpatParser class will no longer create
290 circular references by using itself as the locator that gets passed
291 to the content handler implementation. [SF bug #535474]
292
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000293- The email.Parser.Parser class now properly parses strings regardless
294 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
295 or CRLF). Also, the Header class's constructor default arguments
296 has changed slightly so that an explicit maxlinelen value is always
297 honored.
298
Tim Petersaf8446f2001-12-21 21:36:50 +0000299Tools/Demos
300
Marc-André Lemburg46260092002-04-04 16:17:11 +0000301- freeze.py now produces binaries which can import shared modules,
302 unlike before when this failed due to missing symbol exports in
303 the generated binary.
304
Tim Petersaf8446f2001-12-21 21:36:50 +0000305Build
306
Tim Petersc6a3ff62002-07-08 22:11:52 +0000307- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
308 get into infinite loops, when a new-style class got garbage-collected.
309 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
310 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
311 COUNT_ALLOCS is not enabled by default, in either release or debug
312 builds, and that new-style classes are immortal only in COUNT_ALLOCS
313 builds.
314
Tim Peters943382c2002-07-07 03:59:34 +0000315- Compiling out the cyclic garbage collector is no longer an option.
316 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
317 that it's always defined (for the benefit of any extension modules
318 that may be conditionalizing on it). A bonus is that any extension
319 type participating in cyclic gc can choose to participate in the
320 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
321 to require editing the core to teach the trashcan mechanism about the
322 new type.
323
Tim Peters1de41bf2002-07-03 03:31:20 +0000324- Accoring to Annex F of the current C standard,
325
326 The Standard C macro HUGE_VAL and its float and long double analogs,
327 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
328 positive infinities.
329
330 Python only uses the double HUGE_VAL, and only to #define its own symbol
331 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
332 pyport.h used to try to worm around that, but the workarounds triggered
333 other bugs on other platforms, so we gave up. If your platform defines
334 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
335 that works on your platform. The only instance of this I'm sure about
336 is on an unknown subset of Cray systems, described here:
337
338 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
339
340 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
341
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000342- The configure option --without-doc-strings can be used to remove the
343 doc strings from the builtin functions and modules; this reduces the
344 size of the executable.
345
Tim Peters639295f2002-04-21 07:30:30 +0000346- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
347 say how or when to configure it, or how to turn it off.
348
Martin v. Löwis1142de32002-03-29 16:28:31 +0000349- On Unix, a shared libpython2.3.so can be created with --enable-shared.
350
Tim Peters8deda702002-03-30 10:06:07 +0000351- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
352 preprocessor symbols were eliminated. The internal decisions they
353 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000354
Fred Drake7d28b732002-05-02 21:17:00 +0000355- The tools used to build the documentation now work under Cygwin as
356 well as Unix.
357
Skip Montanaro57454e52002-06-14 20:30:31 +0000358- The bsddb and dbm module builds have been changed to try and avoid version
359 skew problems and disable linkage with Berkeley DB 1.85 unless the
360 installer knows what s/he's doing. See the section on building these
361 modules in the README file for details.
362
Tim Petersaf8446f2001-12-21 21:36:50 +0000363C API
364
Tim Peters7c321a82002-07-09 02:57:01 +0000365- Py_FatalError() is now declared as taking a const char* argument. It
366 was previously declared without const. This should not affect working
367 code.
368
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000369- Added new macro PySequence_ITEM(o, i) that directly calls
370 sq_item without rechecking that o is a sequence and without
371 adjusting for negative indices.
372
Fred Draked0ba6362002-05-02 21:28:26 +0000373- PyRange_New() now raises ValueError if the fourth argument is not 1.
374 This is part of the removal of deprecated features of the xrange
375 object.
376
Guido van Rossum517c7d42002-04-26 02:49:14 +0000377- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
378 coercion if both arguments have the same type but this type has the
379 CHECKTYPES flag set. This is to better support proxies.
380
Neil Schemenauer9344b142002-04-12 23:00:08 +0000381- The type of tp_free has been changed from "void (*)(PyObject *)" to
382 "void (*)(void *)".
383
384- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
385
Guido van Rossum0986d822002-04-08 01:38:42 +0000386- A type can now inherit its metatype from its base type. Previously,
387 when PyType_Ready() was called, if ob_type was found to be NULL, it
388 was always set to &PyType_Type; now it is set to base->ob_type,
389 where base is tp_base, defaulting to &PyObject_Type.
390
391- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
392
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000393- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000394
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000395- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000396 without going through the buffer API.
397
Martin v. Löwis7198a522002-01-01 19:59:11 +0000398- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
399
Tim Peters10a3bb52001-12-25 19:07:38 +0000400- An old #define of ANY as void has been removed from pyport.h. This
401 hasn't been used since Python's pre-ANSI days, and the #define has
402 been marked as obsolete since then. SF bug 495548 says it created
403 conflicts with other packages, so keeping it around wasn't harmless.
404
Tim Petersaf8446f2001-12-21 21:36:50 +0000405- Because Python's magic number scheme broke on January 1st, we decided
406 to stop Python development. Thanks for all the fish!
407
Tim Petersfb05db22002-03-11 00:24:00 +0000408- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000409 scheme to a new one. See Python/import.c for details.
410
Tim Petersaf8446f2001-12-21 21:36:50 +0000411New platforms
412
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000413- AtheOS is now supported.
414
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000415- GNU/Hurd is now supported.
416
Tim Petersaf8446f2001-12-21 21:36:50 +0000417Tests
418
419Windows
420
Tim Peters08e72952002-04-16 20:48:01 +0000421- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
422 of that has been fixed in the installer (disabled Wise's "delete in-
423 use files" uninstall option).
424
Guido van Rossum181e41a2002-04-06 00:23:25 +0000425- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
426
Tim Peters33187922002-04-04 20:02:04 +0000427- The installer now installs Start menu shortcuts under (the local
428 equivalent of) "All Users" when doing an Admin install.
429
Tim Petersfb05db22002-03-11 00:24:00 +0000430- file.truncate([newsize]) now works on Windows for all newsize values.
431 It used to fail if newsize didn't fit in 32 bits, reflecting a
432 limitation of MS _chsize (which is no longer used).
433
Tim Petersab034fa2002-02-01 11:27:43 +0000434- os.waitpid() is now implemented for Windows, and can be used to block
435 until a specified process exits. This is similar to, but not exactly
436 the same as, os.waitpid() on POSIX systems. If you're waiting for
437 a specific process whose pid was obtained from one of the spawn()
438 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000439 See the docs for details. The docs were changed to clarify that
440 spawn functions return, and waitpid requires, a process handle on
441 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000442
Tim Peters11bd9942002-02-01 00:52:29 +0000443- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000444 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000445 to a nasty problem: before 2.3, if you got a temp file on Windows, it
446 got wrapped in an object whose close() method first closed the
447 underlying file, then deleted the file. This usually worked fine.
448 However, the spawn family of functions on Windows create (at a low C
449 level) the same set of open files in the spawned process Q as were
450 open in the spawning process P. If a temp file f was among them, then
451 doing f.close() in P first closed P's C-level file handle on f, but Q's
452 C-level file handle on f remained open, so the attempt in P to delete f
453 blew up with a "Permission denied" error (Windows doesn't allow
454 deleting open files). This was surprising, subtle, and difficult to
455 work around.
456
457- The os module now exports all the symbolic constants usable with the
458 low-level os.open() on Windows: the new constants in 2.3 are
459 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
460 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
461 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
462 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
463 (so specify both if you want both; note that neither is useful unless
464 specified with O_CREAT too).
465
Tim Petersaf8446f2001-12-21 21:36:50 +0000466Mac
467
468
Tim Peters909c0912001-12-14 23:16:18 +0000469What's New in Python 2.2 final?
470Release date: 21-Dec-2001
471===============================
472
473Type/class unification and new-style classes
474
Barry Warsaw52acb492001-12-21 20:04:22 +0000475- pickle.py, cPickle: allow pickling instances of new-style classes
476 with a custom metaclass.
477
Tim Peters909c0912001-12-14 23:16:18 +0000478Core and builtins
479
Barry Warsaw52acb492001-12-21 20:04:22 +0000480- weakref proxy object: when comparing, unwrap both arguments if both
481 are proxies.
482
Tim Peters909c0912001-12-14 23:16:18 +0000483Extension modules
484
Barry Warsaw52acb492001-12-21 20:04:22 +0000485- binascii.b2a_base64(): fix a potential buffer overrun when encoding
486 very short strings.
487
488- cPickle: the obscure "fast" mode was suspected of causing stack
489 overflows on the Mac. Hopefully fixed this by setting the recursion
490 limit much smaller. If the limit is too low (it only affects
491 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
492 when compiling cPickle.c (or in pyconfig.h).
493
Tim Peters909c0912001-12-14 23:16:18 +0000494Library
495
Barry Warsaw52acb492001-12-21 20:04:22 +0000496- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
497 close or delete time).
498
499- rfc822.py: fixed a bug where the address '<>' was converted to None
500 instead of an empty string (also fixes the email.Utils module).
501
502- xmlrpclib.py: version 1.0.0; uses precision for doubles.
503
504- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000505 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000506
Tim Peters909c0912001-12-14 23:16:18 +0000507Tools/Demos
508
509Build
510
511C API
512
513New platforms
514
515Tests
516
517Windows
518
Barry Warsaw52acb492001-12-21 20:04:22 +0000519- distutils package: fixed broken Windows installers (bdist_wininst).
520
521- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
522 instances are deleted at process exit time.
523
524- socket.py: prevent mysterious warnings when socket instances are
525 deleted at process exit time.
526
527- posixmodule.c: fix a Windows crash with stat() of a filename ending
528 in backslash.
529
Tim Peters909c0912001-12-14 23:16:18 +0000530Mac
531
Barry Warsaw52acb492001-12-21 20:04:22 +0000532- The Carbon toolbox modules have been upgraded to Universal Headers
533 3.4, and experimental CoreGraphics and CarbonEvents modules have
534 been added. All only for framework-enabled MacOSX.
535
Tim Peters909c0912001-12-14 23:16:18 +0000536
Tim Peters6272dfd2001-12-13 19:34:00 +0000537What's New in Python 2.2c1?
538Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000539===========================
540
541Type/class unification and new-style classes
542
Barry Warsaw06557452001-12-14 20:47:12 +0000543- Guido's tutorial introduction to the new type/class features has
544 been extensively updated. See
545
546 http://www.python.org/2.2/descrintro.html
547
548 That remains the primary documentation in this area.
549
Guido van Rossum33bab012001-12-05 22:45:48 +0000550- Fixed a leak: instance variables declared with __slots__ were never
551 deleted!
552
Guido van Rossum4b800852001-12-03 00:54:52 +0000553- The "delete attribute" method of descriptor objects is called
554 __delete__, not __del__. In previous releases, it was mistakenly
555 called __del__, which created an unfortunate overloading condition
556 with finalizers. (The "get attribute" and "set attribute" methods
557 are still called __get__ and __set__, respectively.)
558
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000559- Some subtle issues with the super built-in were fixed:
560
561 (a) When super itself is subclassed, its __get__ method would still
562 return an instance of the base class (i.e., of super).
563
564 (b) super(C, C()).__class__ would return C rather than super. This
565 is confusing. To fix this, I decided to change the semantics of
566 super so that it only applies to code attributes, not to data
567 attributes. After all, overriding data attributes is not
568 supported anyway.
569
570 (c) The __get__ method didn't check whether the argument was an
571 instance of the type used in creation of the super instance.
572
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000573- Previously, hash() of an instance of a subclass of a mutable type
574 (list or dictionary) would return some value, rather than raising
575 TypeError. This has been fixed. Also, directly calling
576 dict.__hash__ and list.__hash__ now raises the same TypeError
577 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000578
Guido van Rossumd331cb52001-12-05 19:46:42 +0000579- New-style objects now support deleting their __dict__. This is for
580 all intents and purposes equivalent to assigning a brand new empty
581 dictionary, but saves space if the object is not used further.
582
Tim Petersb3c9af12001-11-17 00:21:57 +0000583Core and builtins
584
Tim Peters3caca232001-12-06 06:23:26 +0000585- -Qnew now works as documented in PEP 238: when -Qnew is passed on
586 the command line, all occurrences of "/" use true division instead
587 of classic division. See the PEP for details. Note that "all"
588 means all instances in library and 3rd-party modules, as well as in
589 your own code. As the PEP says, -Qnew is intended for use only in
590 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000591 Note that test_coercion.py in the standard Python test suite fails
592 under -Qnew; this is expected, and won't be repaired until true
593 division becomes the default (in the meantime, test_coercion is
594 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000595
Fred Drake6c01e252001-12-14 17:08:12 +0000596- complex() now only allows the first argument to be a string
597 argument, and raises TypeError if either the second arg is a string
598 or if the second arg is specified when the first is a string.
599
Tim Petersb3c9af12001-11-17 00:21:57 +0000600Extension modules
601
Martin v. Löwis560da622001-11-24 09:24:51 +0000602- gc.get_referents was renamed to gc.get_referrers.
603
Tim Petersb3c9af12001-11-17 00:21:57 +0000604Library
605
Tim Peters25059d32001-12-07 20:35:43 +0000606- Functions in the os.spawn() family now release the global interpreter
607 lock around calling the platform spawn. They should always have done
608 this, but did not before 2.2c1. Multithreaded programs calling
609 an os.spawn function with P_WAIT will no longer block all Python threads
610 until the spawned program completes. It's possible that some programs
611 relies on blocking, although more likely by accident than by design.
612
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000613- webbrowser defaults to netscape.exe on OS/2 now.
614
Martin v. Löwis652e1912001-11-25 14:50:56 +0000615- Tix.ResizeHandle exposes detach_widget, hide, and show.
616
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000617- The charset alias windows_1252 has been added.
618
Barry Warsaw06557452001-12-14 20:47:12 +0000619- types.StringTypes is a tuple containing the defined string types;
620 usually this will be (str, unicode), but if Python was compiled
621 without Unicode support it will be just (str,).
622
623- The pulldom and minidom modules were synchronized to PyXML.
624
Tim Petersb3c9af12001-11-17 00:21:57 +0000625Tools/Demos
626
Barry Warsaw06557452001-12-14 20:47:12 +0000627- A new script called Tools/scripts/google.py was added, which fires
628 off a search on Google.
629
Tim Petersb3c9af12001-11-17 00:21:57 +0000630Build
631
Barry Warsaw06557452001-12-14 20:47:12 +0000632- Note that release builds of Python should arrange to define the
633 preprocessor symbol NDEBUG on the command line (or equivalent).
634 In the 2.2 pre-release series we tried to define this by magic in
635 Python.h instead, but it proved to cause problems for extension
636 authors. The Unix, Windows and Mac builds now all define NDEBUG in
637 release builds via cmdline (or equivalent) instead. Ports to
638 other platforms should do likewise.
639
Jack Jansen1999ef42001-12-06 21:47:20 +0000640- It is no longer necessary to use --with-suffix when building on a
641 case-insensitive file system (such as Mac OS X HFS+). In the build
642 directory an extension is used, but not in the installed python.
643
Tim Petersb3c9af12001-11-17 00:21:57 +0000644C API
645
Tim Petersf582b822001-12-11 18:51:08 +0000646- New function PyDict_MergeFromSeq2() exposes the builtin dict
647 constructor's logic for updating a dictionary from an iterable object
648 producing key-value pairs.
649
Tim Peterscffed4b2001-11-29 03:26:37 +0000650- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000651 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000652 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
653 dump core in some bad cases. This has been repaired. As a result,
654 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
655 previously went unchallenged.
656
Tim Petersb3c9af12001-11-17 00:21:57 +0000657New platforms
658
659Tests
660
661Windows
662
663Mac
664
Jack Jansenffa260f2001-12-06 21:14:00 +0000665- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
666 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000667
Barry Warsaw06557452001-12-14 20:47:12 +0000668- Changed logic for finding python home in Mac OS X framework Pythons.
669 Now sys.executable points to the executable again, in stead of to
670 the shared library. The latter is used only for locating the python
671 home.
672
673
Tim Peters84362bc2001-10-19 17:55:30 +0000674What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000675Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000676===========================
677
678Type/class unification and new-style classes
679
Guido van Rossum3d27df02001-11-15 20:27:54 +0000680- Multiple inheritance mixing new-style and classic classes in the
681 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000682
683 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000684 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000685
686 The MRO (method resolution order) for each base class is respected
687 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000688 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000689 This needs to be documented.
690
Tim Petersa427a2b2001-10-29 22:25:45 +0000691- The new builtin dictionary() constructor, and dictionary type, have
692 been renamed to dict. This reflects a decade of common usage.
693
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000694- dict() now accepts an iterable object producing 2-sequences. For
695 example, dict(d.items()) == d for any dictionary d. The argument,
696 and the elements of the argument, can be any iterable objects.
697
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000698- New-style classes can now have a __del__ method, which is called
699 when the instance is deleted (just like for classic classes).
700
Guido van Rossum12d955c2001-10-26 14:56:06 +0000701- Assignment to object.__dict__ is now possible, for objects that are
702 instances of new-style classes that have a __dict__ (unless the base
703 class forbids it).
704
Guido van Rossumc8e56452001-10-22 00:43:43 +0000705- Methods of built-in types now properly check for keyword arguments
706 (formerly these were silently ignored). The only built-in methods
707 that take keyword arguments are __call__, __init__ and __new__.
708
Guido van Rossum86443212001-10-27 22:28:54 +0000709- The socket function has been converted to a type; see below.
710
Tim Peters84362bc2001-10-19 17:55:30 +0000711Core and builtins
712
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000713- Assignment to __debug__ raises SyntaxError at compile-time. This
714 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000715 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000716
Guido van Rossum12d955c2001-10-26 14:56:06 +0000717- Clarified the error messages for unsupported operands to an operator
718 (like 1 + '').
719
Tim Peters84362bc2001-10-19 17:55:30 +0000720Extension modules
721
Tim Peters5ebfd362001-11-13 23:11:19 +0000722- mmap has a new keyword argument, "access", allowing a uniform way for
723 both Windows and Unix users to create read-only, write-through and
724 copy-on-write memory mappings. This was previously possible only on
725 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000726 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000727 platforms. Thanks to Jay T Miller for repairing this!
728
Tim Peters169ded02001-11-03 19:57:21 +0000729- By default, the gc.garbage list now contains only those instances in
730 unreachable cycles that have __del__ methods; in 2.1 it contained all
731 instances in unreachable cycles. "Instances" here has been generalized
732 to include instances of both new-style and old-style classes.
733
Guido van Rossum12d955c2001-10-26 14:56:06 +0000734- The socket module defines a new method for socket objects,
735 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000736 send() until all data has been sent. Also, the socket function has
737 been converted to a subclassable type, like list and tuple (etc.)
738 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000739
740- Various bugfixes to the curses module. There is now a test suite
741 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000742
Guido van Rossum692adf12001-10-30 03:03:03 +0000743- binascii.b2a_base64 no longer places an arbitrary restriction of 57
744 bytes on its input.
745
Tim Peters84362bc2001-10-19 17:55:30 +0000746Library
747
Tim Peters5ebfd362001-11-13 23:11:19 +0000748- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000749 convenience function.
750
Tim Peters75335872001-11-03 19:35:43 +0000751- Symbolic group names in regular expressions must be unique. For
752 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
753 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000754 Python 2.2 detects this error at regexp compilation time;
755 previously, the error went undetected, and results were
756 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
757 pattern.subn() methods have been rewritten in C. Also, an
758 experimental function/method finditer() has been added, which works
759 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000760
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000761- Tix exposes more commands through the classes DirSelectBox,
762 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
763 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
764 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
765
Tim Peters98791af2001-10-23 01:59:54 +0000766- Traceback objects are now scanned by cyclic garbage collection, so
767 cycles created by casual use of sys.exc_info() no longer cause
768 permanent memory leaks (provided garbage collection is enabled).
769
Guido van Rossum49192142001-10-24 20:51:44 +0000770- os.extsep -- a new variable needed by the RISCOS support. It is the
771 separator used by extensions, and is '.' on all platforms except
772 RISCOS, where it is '/'. There is no need to use this variable
773 unless you have a masochistic desire to port your code to RISCOS.
774
Barry Warsaw012852b2001-11-16 16:17:27 +0000775- mimetypes.py has optional support for non-standard, but commonly
776 found types. guess_type() and guess_extension() now accept an
777 optional `strict' flag, defaulting to true, which controls whether
778 recognize non-standard types or not. A few non-standard types we
779 know about have been added. Also, when run as a script, there are
780 new -l and -e options.
781
782- statcache is now deprecated.
783
784- email.Utils.formatdate() now produces the preferred RFC 2822 style
785 dates with numeric timezones (it used to produce obsolete dates
786 hard coded to "GMT" timezone). An optional `localtime' flag is
787 added to produce dates in the local timezone, with daylight savings
788 time properly taken into account.
789
790- In pickle and cPickle, instead of masking errors in load() by
791 transforming them into SystemError, we let the original exception
792 propagate out. Also, implement support for __safe_for_unpickling__
793 in pickle, as it already was supported in cPickle.
794
Tim Peters84362bc2001-10-19 17:55:30 +0000795Tools/Demos
796
797Build
798
Barry Warsaw012852b2001-11-16 16:17:27 +0000799- The dbm module is built using libdb1 if available. The bsddb module
800 is built with libdb3 if available.
801
802- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
803
Tim Peters84362bc2001-10-19 17:55:30 +0000804C API
805
Tim Peters1fc240e2001-10-26 05:06:50 +0000806- New function PySequence_Fast_GET_SIZE() returns the size of a non-
807 NULL result from PySequence_Fast(), more quickly than calling
808 PySequence_Size().
809
Barry Warsaw012852b2001-11-16 16:17:27 +0000810- New argument unpacking function PyArg_UnpackTuple() added.
811
812- New functions PyObject_CallFunctionObjArgs() and
813 PyObject_CallMethodObjArgs() have been added to make it more
814 convenient and efficient to call functions and methods from C.
815
816- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
817 possible that this will propagate errors it didn't before.
818
819- New function PyObject_CheckReadBuffer(), which returns true if its
820 argument supports the single-segment readable buffer interface.
821
Tim Peters84362bc2001-10-19 17:55:30 +0000822New platforms
823
Guido van Rossum86443212001-10-27 22:28:54 +0000824- We've finally confirmed that this release builds on HP-UX 11.00,
825 *with* threads, and passes the test suite.
826
Tim Peters7a33d8b2001-11-05 02:51:07 +0000827- Thanks to a series of patches from Michael Muller, Python may build
828 again under OS/2 Visual Age C++.
829
Guido van Rossum49192142001-10-24 20:51:44 +0000830- Updated RISCOS port by Dietmar Schwertberger.
831
Tim Peters84362bc2001-10-19 17:55:30 +0000832Tests
833
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000834- Added a test script for the curses module. It isn't run automatically;
835 regrtest.py must be run with '-u curses' to enable it.
836
Tim Peters84362bc2001-10-19 17:55:30 +0000837Windows
838
Barry Warsaw012852b2001-11-16 16:17:27 +0000839Mac
840
841- PythonScript has been moved to unsupported and is slated to be
842 removed completely in the next release.
843
844- It should now be possible to build applets that work on both OS9 and
845 OSX.
846
847- The core is now linked with CoreServices not Carbon; as a side
848 result, default 8bit encoding on OSX is now ASCII.
849
850- Python should now build on OSX 10.1.1
851
Tim Peters84362bc2001-10-19 17:55:30 +0000852
Tim Petersabf925f2001-09-28 21:53:42 +0000853What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000854Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000855===========================
856
857Type/class unification and new-style classes
858
Guido van Rossum687ae002001-10-15 22:03:32 +0000859- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000860 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000861 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000862 remains: the __dict__ of a new-style class is a read-only proxy; you
863 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000864 __defined__ attribute of new-style types no longer exists, for lack
865 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000866 future a __cache__ may be resurrected with a similar function, if I
867 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000868
Tim Peters1c9ca872001-10-04 06:43:12 +0000869- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
870 always returned None, even when there was a class docstring).
871
872- doctest now finds and runs docstrings attached to new-style classes,
873 class methods, static methods, and properties.
874
Guido van Rossum9074ef62001-10-16 21:34:49 +0000875Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000876
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000877- A very subtle syntactical pitfall in list comprehensions was fixed.
878 For example: [a+b for a in 'abc', for b in 'def']. The comma in
879 this example is a mistake. Previously, this would silently let 'a'
880 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
881 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
882 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
883 Note that [a for a in <singleton>] is a convoluted way to say
884 [<singleton>] anyway, so it's not like any expressiveness is lost.
885
Guido van Rossum9074ef62001-10-16 21:34:49 +0000886- getattr(obj, name, default) now only catches AttributeError, as
887 documented, rather than returning the default value for all
888 exceptions (which could mask bugs in a __getattr__ hook, for
889 example).
890
Fred Drakecb7a6b52001-10-22 18:41:51 +0000891- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000892 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000893 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000894 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000895
Guido van Rossum1c486092001-10-19 02:05:35 +0000896- unicode(obj) now behaves more like str(obj), accepting arbitrary
897 objects, and calling a __unicode__ method if it exists.
898 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000899 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000900
Barry Warsawf6fb1712001-10-19 05:35:40 +0000901- isinstance() now allows any object as the first argument and a
902 class, a type or something with a __bases__ tuple attribute for the
903 second argument. The second argument may also be a tuple of a
904 class, type, or something with __bases__, in which case isinstance()
905 will return true if the first argument is an instance of any of the
906 things contained in the second argument tuple. E.g.
907
908 isinstance(x, (A, B))
909
910 returns true if x is an instance of A or B.
911
Guido van Rossum9074ef62001-10-16 21:34:49 +0000912Extension modules
913
914- thread.start_new_thread() now returns the thread ID (previously None).
915
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000916- binascii has now two quopri support functions, a2b_qp and b2a_qp.
917
Guido van Rossumc524d952001-10-19 01:31:59 +0000918- readline now supports setting the startup_hook and the
919 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000920
Guido van Rossumc524d952001-10-19 01:31:59 +0000921- os and posix supports chroot(), setgroups() and unsetenv() where
922 available. The stat(), fstat(), statvfs() and fstatvfs() functions
923 now return "pseudo-sequences" -- the various fields can now be
924 accessed as attributes (e.g. os.stat("/").st_mtime) but for
925 backwards compatibility they also behave as a fixed-length sequence.
926 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000927 attributes.
928
929- time: localtime(), gmtime() and strptime() now return a
930 pseudo-sequence similar to the os.stat() return value, with
931 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000932
Guido van Rossum9074ef62001-10-16 21:34:49 +0000933- Decompression objects in the zlib module now accept an optional
934 second parameter to decompress() that specifies the maximum amount
935 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000936
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000937- optional SSL support in the socket module now exports OpenSSL
938 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
939 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000940 automatically seed its PRNG. Also, the keyfile and certfile
941 arguments to socket.ssl() are now optional.
942
943- posixmodule (and by extension, the os module on POSIX platforms) now
944 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000945
Guido van Rossum9074ef62001-10-16 21:34:49 +0000946Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000947
Tim Peters7402f792001-10-02 03:53:41 +0000948- doctest now excludes functions and classes not defined by the module
949 being tested, thanks to Tim Hochberg.
950
Fred Drakecb7a6b52001-10-22 18:41:51 +0000951- HotShot, a new profiler implemented using a C-based callback, has
952 been added. This substantially reduces the overhead of profiling,
953 but it is still quite preliminary. Support modules and
954 documentation will be added in upcoming releases (before 2.2 final).
955
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000956- profile now produces correct output in situations where an exception
957 raised in Python is cleared by C code (e.g. hasattr()). This used
958 to cause wrong output, including spurious claims of recursive
959 functions and attribution of time spent to the wrong function.
960
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000961 The code and documentation for the derived OldProfile and HotProfile
962 profiling classes was removed. The code hasn't worked for years (if
963 you tried to use them, they raised exceptions). OldProfile
964 intended to reproduce the behavior of the profiler Python used more
965 than 7 years ago, and isn't interesting anymore. HotProfile intended
966 to provide a faster profiler (but producing less information), and
967 that's a worthy goal we intend to meet via a different approach (but
968 without losing information).
969
Tim Peterscce092d2001-10-09 05:31:56 +0000970- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000971 a much better system-specific calibration constant. The constant can
972 now be specified in an instance constructor, or as a Profile class or
973 instance variable, instead of by editing profile.py's source code.
974 Calibration must still be done manually (see the docs for the profile
975 module).
976
977 Note that Profile.calibrate() must be overriden by subclasses.
978 Improving the accuracy required exploiting detailed knowledge of
979 profiler internals; the earlier method abstracted away the details
980 and measured a simplified model instead, but consequently computed
981 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000982
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000983- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000984 which indicates whether output is intended for the header 'Q'
985 encoding.
986
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000987- The SocketServer.ThreadingMixIn class now closes the request after
988 finish_request() returns. (Not when it errors out though.)
989
Barry Warsawf6fb1712001-10-19 05:35:40 +0000990- The nntplib module's NNTP.body() method has grown a `file' argument
991 to allow saving the message body to a file.
992
993- The email package has added a class email.Parser.HeaderParser which
994 only parses headers and does not recurse into the message's body.
995 Also, the module/class MIMEAudio has been added for representing
996 audio data (contributed by Anthony Baxter).
997
998- ftplib should be able to handle files > 2GB.
999
1000- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1001 ON, and OFF.
1002
Fred Drakecb7a6b52001-10-22 18:41:51 +00001003- xml.dom.minidom NodeList objects now support the length attribute
1004 and item() method as required by the DOM specifications.
1005
Guido van Rossumed554f62001-10-02 23:15:37 +00001006Tools/Demos
1007
1008- Demo/dns was removed. It no longer serves any purpose; a package
1009 derived from it is now maintained by Anthony Baxter, see
1010 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001011
Barry Warsawf6fb1712001-10-19 05:35:40 +00001012- The freeze tool has been made more robust, and two new options have
1013 been added: -X and -E.
1014
Tim Petersabf925f2001-09-28 21:53:42 +00001015Build
1016
Barry Warsawf6fb1712001-10-19 05:35:40 +00001017- configure will use CXX in LINKCC if CXX is used to build main() and
1018 the system requires to link a C++ main using the C++ compiler.
1019
Tim Petersabf925f2001-09-28 21:53:42 +00001020C API
1021
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001022- The documentation for the tp_compare slot is updated to require that
1023 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1024 not correct. This is not yet enforced but will be enforced in
1025 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1026 "NotImplemented". Right now, -1 should be used for an error return.
1027
Tim Petersd38b1c72001-09-30 05:09:37 +00001028- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1029 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1030 as long) arguments.
1031
Guido van Rossum3c288632001-10-16 21:13:49 +00001032- PyThread_start_new_thread() now returns a long int giving the thread
1033 ID, if one can be calculated; it returns -1 for error, 0 if no
1034 thread ID is calculated (this is an incompatible change, but only
1035 the thread module used this API). This code has only really been
1036 tested on Linux and Windows; other platforms please beware (and
1037 report any bugs or strange behavior).
1038
Guido van Rossum1c486092001-10-19 02:05:35 +00001039- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1040 input.
1041
Tim Petersabf925f2001-09-28 21:53:42 +00001042New platforms
1043
1044Tests
1045
1046Windows
1047
Tim Peters04cf1d32001-10-09 22:39:40 +00001048- Installer: If you install IDLE, and don't disable file-extension
1049 registration, a new "Edit with IDLE" context (right-click) menu entry
1050 is created for .py and .pyw files.
1051
Tim Peters1ce3cf72001-10-01 17:58:40 +00001052- The signal module now supports SIGBREAK on Windows, thanks to Steven
1053 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1054 action remains to call Win32 ExitProcess(). This can be changed via
1055 signal.signal(). For example:
1056
1057 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1058 # (SIGINT) behavior.
1059 import signal
1060 signal.signal(signal.SIGBREAK,
1061 signal.default_int_handler)
1062
1063 try:
1064 while 1:
1065 pass
1066 except KeyboardInterrupt:
1067 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1068 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1069 # program without the possibility for any Python-level cleanup).
1070 print "Clean exit"
1071
Tim Petersabf925f2001-09-28 21:53:42 +00001072
Tim Petersb07352e2001-09-08 01:25:47 +00001073What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001074Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001075===========================
1076
Guido van Rossum808eea72001-09-25 04:15:41 +00001077Type/class unification and new-style classes
1078
1079- pydoc and inspect are now aware of new-style classes;
1080 e.g. help(list) at the interactive prompt now shows proper
1081 documentation for all operations on list objects.
1082
1083- Applications using Jim Fulton's ExtensionClass module can now safely
1084 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1085 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1086 examples also work again. It is hoped that Gtk and Boost also work
1087 with 2.2a4 and beyond. (If you can confirm this, please write
1088 webmaster@python.org; if there are still problems, please open a bug
1089 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001090
Tim Peters66c1a522001-09-24 21:17:50 +00001091- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001092 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001093 in the constructed property object. fget, fset and fdel weren't
1094 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1095 associate a docstring with a property.
1096
Guido van Rossum808eea72001-09-25 04:15:41 +00001097- Comparison overloading is now more completely implemented. For
1098 example, a str subclass instance can properly be compared to a str
1099 instance, and it can properly overload comparison. Ditto for most
1100 other built-in object types.
1101
1102- The repr() of new-style classes has changed; instead of <type
1103 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1104 *except* for built-in types, which are still rendered as <type
1105 'Foo'> (to avoid upsetting existing code that might parse or
1106 otherwise rely on repr() of certain type objects).
1107
1108- The repr() of new-style objects is now always <Foo object at XXX>;
1109 previously, it was sometimes <Foo instance at XXX>.
1110
1111- For new-style classes, what was previously called __getattr__ is now
1112 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001113 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001114 one in classic classes is defined which is called only if regular
1115 attribute access raises AttributeError; to catch *all* attribute
1116 access, you can use __getattribute__ (for new-style classes). If
1117 both are defined, __getattribute__ is called first, and if it raises
1118 AttributeError, __getattr__ is called.
1119
1120- The __class__ attribute of new-style objects can be assigned to.
1121 The new class must have the same C-level object layout as the old
1122 class.
1123
1124- The builtin file type can be subclassed now. In the usual pattern,
1125 "file" is the name of the builtin type, and file() is a new builtin
1126 constructor, with the same signature as the builtin open() function.
1127 file() is now the preferred way to open a file.
1128
1129- Previously, __new__ would only see sequential arguments passed to
1130 the type in a constructor call; __init__ would see both sequential
1131 and keyword arguments. This made no sense whatsoever any more, so
1132 now both __new__ and __init__ see all arguments.
1133
1134- Previously, hash() applied to an instance of a subclass of str or
1135 unicode always returned 0. This has been repaired.
1136
1137- Previously, an operation on an instance of a subclass of an
1138 immutable type (int, long, float, complex, tuple, str, unicode),
1139 where the subtype didn't override the operation (and so the
1140 operation was handled by the builtin type), could return that
1141 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001142 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001143 with the same value as s.
1144
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001145- Provisional support for pickling new-style objects has been added.
1146
Guido van Rossum808eea72001-09-25 04:15:41 +00001147Core
1148
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001149- file.writelines() now accepts any iterable object producing strings.
1150
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001151- PyUnicode_FromEncodedObject() now works very much like
1152 PyObject_Str(obj) in that it tries to use __str__/tp_str
1153 on the object if the object is not a string or buffer. This
1154 makes unicode() behave like str() when applied to non-string/buffer
1155 objects.
1156
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001157- PyFile_WriteObject now passes Unicode objects to the file's write
1158 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001159 of a print statement must support Unicode objects, i.e. they must
1160 at least convert them into ASCII strings.
1161
Guido van Rossum624c8af2001-09-18 15:21:04 +00001162- Thread scheduling on Solaris should be improved; it is no longer
1163 necessary to insert a small sleep at the start of a thread in order
1164 to let other runnable threads be scheduled.
1165
Tim Petersb07352e2001-09-08 01:25:47 +00001166Library
1167
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001168- StringIO.StringIO instances and cStringIO.StringIO instances support
1169 read character buffer compatible objects for their .write() methods.
1170 These objects are converted to strings and then handled as such
1171 by the instances.
1172
Barry Warsaw2f600732001-09-24 04:28:10 +00001173- The "email" package has been added. This is basically a port of the
1174 mimelib package <http://sf.net/projects/mimelib> with API changes
1175 and some implementations updated to use iterators and generators.
1176
Tim Peters8a9c2842001-09-22 21:30:22 +00001177- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1178 restores the ability of Tools/scripts/ndiff.py to start producing output
1179 before the entire comparison is complete.
1180
Barry Warsaw58b072d2001-09-22 04:44:21 +00001181- StringIO.StringIO instances and cStringIO.StringIO instances support
1182 iteration just like file objects (i.e. their .readline() method is
1183 called for each iteration until it returns an empty string).
1184
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001185- The codecs module has grown four new helper APIs to access
1186 builtin codecs: getencoder(), getdecoder(), getreader(),
1187 getwriter().
1188
Guido van Rossum624c8af2001-09-18 15:21:04 +00001189- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1190 simplifies writing XML RPC servers.
1191
Barry Warsaw647d5e82001-09-28 17:01:02 +00001192- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001193 after interpretation of symbolic links. On non-Unix systems, this
1194 is an alias for os.path.abspath().
1195
Tim Peters16a77ad2001-09-08 04:00:12 +00001196- operator.indexOf() (PySequence_Index() in the C API) now works with any
1197 iterable object.
1198
Guido van Rossum624c8af2001-09-18 15:21:04 +00001199- smtplib now supports various authentication and security features of
1200 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001201
Guido van Rossum624c8af2001-09-18 15:21:04 +00001202- hmac: a new module implementing keyed hashing for message
1203 authentication.
1204
1205- mimetypes now recognizes more extensions and file types. At the
1206 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001207
Guido van Rossum624c8af2001-09-18 15:21:04 +00001208- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001209 Python 2.2 bytecode generation. It has also been promoted from a
1210 Tool to a standard library package. (Tools/compiler still exists as
1211 a sample driver.)
1212
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001213Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001214
Tim Petersb07352e2001-09-08 01:25:47 +00001215Build
1216
Guido van Rossum624c8af2001-09-18 15:21:04 +00001217- Large file support (LFS) is now automatic when the platform supports
1218 it; no more manual configuration tweaks are needed. On Linux, at
1219 least, it's possible to have a system whose C library supports large
1220 files but whose kernel doesn't; in this case, large file support is
1221 still enabled but doesn't do you any good unless you upgrade your
1222 kernel or share your Python executable with another system whose
1223 kernel has large file support.
1224
1225- The configure script now supplies plausible defaults in a
1226 cross-compilation environment. This doesn't mean that the supplied
1227 values are always correct, or that cross-compilation now works
1228 flawlessly -- but it's a first step (and it shuts up most of
1229 autoconf's warnings about AC_TRY_RUN).
1230
1231- The Unix build is now a bit less chatty, courtesy of the parser
1232 generator. The build is completely silent (except for errors) when
1233 using "make -s", thanks to a -q option to setup.py.
1234
Tim Petersb07352e2001-09-08 01:25:47 +00001235C API
1236
Guido van Rossum624c8af2001-09-18 15:21:04 +00001237- The "structmember" API now supports some new flag bits to deny read
1238 and/or write access to attributes in restricted execution mode.
1239
Tim Petersb07352e2001-09-08 01:25:47 +00001240New platforms
1241
Guido van Rossum624c8af2001-09-18 15:21:04 +00001242- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1243 (http://familiar.handhelds.org).
1244
Tim Petersb07352e2001-09-08 01:25:47 +00001245Tests
1246
Tim Peters8a9c2842001-09-22 21:30:22 +00001247- The "classic" standard tests, which work by comparing stdout to
1248 an expected-output file under Lib/test/output/, no longer stop at
1249 the first mismatch. Instead the test is run to completion, and a
1250 variant of ndiff-style comparison is used to report all differences.
1251 This is much easier to understand than the previous style of reporting.
1252
1253- The unittest-based standard tests now use regrtest's test_main()
1254 convention, instead of running as a side-effect of merely being
1255 imported. This allows these tests to be run in more natural and
1256 flexible ways as unittests, outside the regrtest framework.
1257
1258- regrtest.py is much better integrated with unittest and doctest now,
1259 especially in regard to reporting errors.
1260
Tim Petersb07352e2001-09-08 01:25:47 +00001261Windows
1262
Guido van Rossum624c8af2001-09-18 15:21:04 +00001263- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001264 that support it (NTFS under Windows 2000). See "What's New in
1265 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001266
Tim Petersb07352e2001-09-08 01:25:47 +00001267
Tim Petersedc99312001-08-22 21:36:50 +00001268What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001269Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001270===========================
1271
1272Core
1273
Tim Peters9fffa3e2001-09-04 05:14:19 +00001274- Conversion of long to float now raises OverflowError if the long is too
1275 big to represent as a C double.
1276
Tim Peters32f453e2001-09-03 08:35:41 +00001277- The 3-argument builtin pow() no longer allows a third non-None argument
1278 if either of the first two arguments is a float, or if both are of
1279 integer types and the second argument is negative (in which latter case
1280 the arguments are converted to float, so this is really the same
1281 restriction).
1282
Tim Peters5d2b77c2001-09-03 05:47:38 +00001283- The builtin dir() now returns more information, and sometimes much
1284 more, generally naming all attributes of an object, and all attributes
1285 reachable from the object via its class, and from its class's base
1286 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1287 an empty list. In 2.2a3,
1288
1289 >>> dir([])
1290 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1291 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1292 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1293 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1294 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1295 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1296 'reverse', 'sort']
1297
1298 dir(module) continues to return only the module's attributes, though.
1299
Tim Petersbdee63f2001-09-02 03:40:59 +00001300- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001301 than raising OverflowError. This is a partial implementation of PEP
1302 237. You can use -Wdefault::OverflowWarning to enable a warning for
1303 this situation, and -Werror::OverflowWarning to revert to the old
1304 OverflowError exception.
1305
Guido van Rossum61c345f2001-09-04 03:26:15 +00001306- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001307 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001308 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1309 -Qold, meaning the / operator has its classic meaning and no
1310 warnings are issued. Using -Qwarn issues a run-time warning about
1311 all uses of classic division for int and long arguments; -Qwarnall
1312 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001313 (for use with fixdiv.py).
1314 [Note: the remainder of this paragraph (preserved below) became
1315 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1316 <obsolete>
1317 Using -Qnew is questionable; it turns on new division by default, but
1318 only in the __main__ module. You can usefully combine -Qwarn or
1319 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1320 warns about classic division everywhere else.
1321 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001322
Tim Petersbdee63f2001-09-02 03:40:59 +00001323- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001324 long, float, str, unicode, and tuple. (The types complex, list and
1325 dictionary can also be subclassed; this was introduced earlier.)
1326 Note that restrictions apply when subclassing immutable built-in
1327 types: you can only affect the value of the instance by overloading
1328 __new__. You can add mutable attributes, and the subclass instances
1329 will have a __dict__ attribute, but you cannot change the "value"
1330 (as implemented by the base class) of an immutable subclass instance
1331 once it is created.
1332
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001333- The dictionary constructor now takes an optional argument, a
1334 mapping-like object, and initializes the dictionary from its
1335 (key, value) pairs.
1336
Tim Petersbdee63f2001-09-02 03:40:59 +00001337- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001338 "cooperative super calls" in a multiple inheritance setting. For an
1339 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1340
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001341- A new built-in type, property, has been added. This enables the
1342 creation of "properties". These are attributes implemented by
1343 getter and setter functions (or only one of these for read-only or
1344 write-only attributes), without the need to override __getattr__.
1345 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001346
Tim Petersbdee63f2001-09-02 03:40:59 +00001347- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001348 liberalized, to allow leading zeroes. Examples of literals now
1349 legal that were SyntaxErrors before:
1350
1351 00.0 0e3 0100j 07.5 00000000000000000008.
1352
Tim Petersbdee63f2001-09-02 03:40:59 +00001353- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001354 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1355
Tim Petersedc99312001-08-22 21:36:50 +00001356Library
1357
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001358- telnetlib includes symbolic names for the options, and support for
1359 setting an option negotiation callback.
1360
Tim Petersa40c7932001-09-05 22:36:56 +00001361- The new C standard no longer requires that math libraries set errno to
1362 ERANGE on overflow. For platform libraries that exploit this new
1363 freedom, Python's overflow-checking was wholly broken. A new overflow-
1364 checking scheme attempts to repair that, but may not be reliable on all
1365 platforms (C doesn't seem to provide anything both useful and portable
1366 in this area anymore).
1367
Martin v. Löwis44f86962001-09-05 13:44:54 +00001368- Asynchronous timeout actions are available through the new class
1369 threading.Timer.
1370
Tim Peters78526162001-09-05 00:53:45 +00001371- math.log and math.log10 now return sensible results for even huge
1372 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1373
Tim Petersbdee63f2001-09-02 03:40:59 +00001374- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001375 currently held. See the docs for the imp module.
1376
Tim Petersbdee63f2001-09-02 03:40:59 +00001377- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001378 dumps containing ints written on platforms where Python ints are 8 bytes.
1379 When read on a box where Python ints are 4 bytes, such values are
1380 converted to Python longs.
1381
Tim Petersbdee63f2001-09-02 03:40:59 +00001382- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001383 code objects is no longer allowed. This plugs a security hole.
1384
Steve Purcell6091cd62001-09-06 16:05:17 +00001385- unittest.TestResult instances no longer store references to tracebacks
1386 generated by test failures. This prevents unexpected dangling references
1387 to objects that should be garbage collected between tests.
1388
Tim Petersedc99312001-08-22 21:36:50 +00001389Tools
1390
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001391- Tools/scripts/fixdiv.py has been added which can be used to fix
1392 division operators as per PEP 238.
1393
Tim Petersedc99312001-08-22 21:36:50 +00001394Build
1395
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001396- If you are an adventurous person using Mac OS X you may want to look at
1397 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1398 application, which can be used for experimenting with Carbon or Cocoa.
1399 Discussion of this on pythonmac-sig, please.
1400
Tim Peters7eea37e2001-09-04 22:08:56 +00001401C API
1402
1403- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001404
Tim Peters9fffa3e2001-09-04 05:14:19 +00001405- Note that PyLong_AsDouble can fail! This has always been true, but no
1406 callers checked for it. It's more likely to fail now, because overflow
1407 errors are properly detected now. The proper way to check:
1408
1409 double x = PyLong_AsDouble(some_long_object);
1410 if (x == -1.0 && PyErr_Occurred()) {
1411 /* The conversion failed. */
1412 }
1413
Tim Petersbdee63f2001-09-02 03:40:59 +00001414- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001415 compile but will not participate in GC. To upgrade an extension
1416 module:
1417
1418 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001419
Neil Schemenauer4042c692001-08-30 15:38:01 +00001420 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1421 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001422
Neil Schemenauer4042c692001-08-30 15:38:01 +00001423 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1424 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001425
Neil Schemenauer4042c692001-08-30 15:38:01 +00001426 - remove PyGC_HEAD_SIZE from object size calculations
1427
1428 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1429
Tim Petersbdee63f2001-09-02 03:40:59 +00001430- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001431 These can be used safely to construct string objects from a
1432 sprintf-style format string (similar to the format string supported
1433 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001434
Tim Petersedc99312001-08-22 21:36:50 +00001435New platforms
1436
Tim Petersb7da0902001-09-02 23:01:43 +00001437- Stephen Hansen contributed patches sufficient to get a clean compile
1438 under Borland C (Windows), but he reports problems running it and ran
1439 out of time to complete the port. Volunteers? Expect a MemoryError
1440 when importing the types module; this is probably shallow, and
1441 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001442
Tim Petersedc99312001-08-22 21:36:50 +00001443Tests
1444
1445Windows
1446
Tim Peters6e13a562001-09-06 00:32:15 +00001447- Large file support is now enabled on Win32 platforms as well as on
1448 Win64. This means that, for example, you can use f.tell() and f.seek()
1449 to manipulate files larger than 2 gigabytes (provided you have enough
1450 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001451 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1452 filesize limit, and large file support makes no difference there.
1453 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1454 NTFS has no practical limit on file size, and files of any size can be
1455 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001456
Tim Petersbdee63f2001-09-02 03:40:59 +00001457- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001458 points to command.com (patch from Brian Quinlan).
1459
Tim Petersedc99312001-08-22 21:36:50 +00001460
Tim Peters20f51a72001-07-21 02:31:40 +00001461What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001462Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001463===========================
1464
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001465Build
1466
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001467- Tim Peters developed a brand new Windows installer using Wise 8.1,
1468 generously donated to us by Wise Solutions.
1469
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001470- configure supports a new option --enable-unicode, with the values
1471 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1472 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001473
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001474- A new configure option --enable-framework builds a Mac OS X framework,
1475 which "make frameworkinstall" will install. This provides a starting
1476 point for more mac-like functionality, join pythonmac-sig@python.org
1477 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001478
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001479- The NeXT platform is no longer supported.
1480
1481- The `new' module is now statically linked.
1482
Tim Peters0afb6092001-08-15 06:06:44 +00001483Tools
1484
1485- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001486 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001487 the module docstring for details.
1488
Tim Peters20f51a72001-07-21 02:31:40 +00001489Tests
1490
Tim Peters5e824c32001-08-12 22:25:01 +00001491- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001492 platforms, allowing to give clearer test result output. regrtest
1493 also has optional --use/-u switch to run normally disabled tests
1494 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001495
Tim Peters20f51a72001-07-21 02:31:40 +00001496- Several new tests in the standard test suite, with special thanks to
1497 Nick Mathewson.
1498
1499Core
1500
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001501- The floor division operator // has been added as outlined in PEP
1502 238. The / operator still provides classic division (and will until
1503 Python 3.0) unless "from __future__ import division" is included, in
1504 which case the / operator will provide true division. The operator
1505 module provides truediv() and floordiv() functions. Augmented
1506 assignment variants are included, as are the equivalent overloadable
1507 methods and C API methods. See the PEP for a full discussion:
1508 <http://python.sf.net/peps/pep-0238.html>
1509
Tim Peters6cd6a822001-08-17 22:11:27 +00001510- Future statements are now effective in simulated interactive shells
1511 (like IDLE). This should "just work" by magic, but read Michael
1512 Hudson's "Future statements in simulated shells" PEP 264 for full
1513 details: <http://python.sf.net/peps/pep-0264.html>.
1514
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001515- The type/class unification (PEP 252-253) was integrated into the
1516 trunk and is not so tentative any more (the exact specification of
1517 some features is still tentative). A lot of work has done on fixing
1518 bugs and adding robustness and features (performance still has to
1519 come a long way).
1520
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001521- Warnings about a mismatch in the Python API during extension import
1522 now use the Python warning framework (which makes it possible to
1523 write filters for these warnings).
1524
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001525- A function's __dict__ (aka func_dict) will now always be a
1526 dictionary. It used to be possible to delete it or set it to None,
1527 but now both actions raise TypeErrors. It is still legal to set it
1528 to a dictionary object. Getting func.__dict__ before any attributes
1529 have been assigned now returns an empty dictionary instead of None.
1530
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001531- A new command line option, -E, was added which disables the use of
1532 all environment variables, or at least those that are specifically
1533 significant to Python. Usually those have a name starting with
1534 "PYTHON". This was used to fix a problem where the tests fail if
1535 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1536 older distribution.
1537
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001538Library
1539
Tim Peters5e824c32001-08-12 22:25:01 +00001540- New class Differ and new functions ndiff() and restore() in difflib.py.
1541 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001542 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001543
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001544- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1545 value using the minimal quoting required for the value; more
1546 reliable than using xml.sax.saxutils.escape() for attribute values.
1547
1548- Readline completion support for cmd.Cmd was added.
1549
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001550- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1551
1552- Added function threading.BoundedSemaphore()
1553
1554- Added Ka-Ping Yee's cgitb.py module.
1555
1556- The `new' module now exposes the CO_xxx flags.
1557
Martin v. Löwis560da622001-11-24 09:24:51 +00001558- The gc module offers the get_referents function.
1559
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001560New platforms
1561
1562C API
1563
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001564- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1565 which provide a cross-platform implementations for the
1566 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1567 the standard sprintf() and vsprintf() C lib APIs, these versions
1568 apply bounds checking on the used buffer which enhances protection
1569 against buffer overruns.
1570
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001571- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001572 and extensions using different Unicode widths is rendered next to
1573 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001574 will result in an ImportError. Unicode extensions writers must make
1575 sure to check the Unicode width compatibility in their extensions by
1576 using at least one of the mangled Unicode APIs in the extension.
1577
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001578- Two new flags METH_NOARGS and METH_O are available in method definition
1579 tables to simplify implementation of methods with no arguments and a
1580 single untyped argument. Calling such methods is more efficient than
1581 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1582 deprecated.
1583
Tim Petersc1731372001-08-04 08:12:36 +00001584Windows
1585
1586- "import module" now compiles module.pyw if it exists and nothing else
1587 relevant is found.
1588
Tim Peters20f51a72001-07-21 02:31:40 +00001589
Guido van Rossum55a78992001-07-17 17:22:32 +00001590What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001591Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001592===========================
1593
1594Core
Tim Petersa814db52001-05-14 07:05:58 +00001595
Tim Peters6d6c1a32001-08-02 04:15:00 +00001596- TENTATIVELY, a large amount of code implementing much of what's
1597 described in PEP 252 (Making Types Look More Like Classes) and PEP
1598 253 (Subtyping Built-in Types) was added. This will be released
1599 with Python 2.2a1. Documentation will be provided separately
1600 through http://www.python.org/2.2/. The purpose of releasing this
1601 with Python 2.2a1 is to test backwards compatibility. It is
1602 possible, though not likely, that a decision is made not to release
1603 this code as part of 2.2 final, if any serious backwards
1604 incompapatibilities are found during alpha testing that cannot be
1605 repaired.
1606
Guido van Rossum55a78992001-07-17 17:22:32 +00001607- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001608 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001609 more 'yield' statements. See PEP 255. Since this adds a new
1610 keyword to the language, this feature must be enabled by including a
1611 future statement: "from __future__ import generators" (see PEP 236).
1612 Generators will become a standard feature in a future release
1613 (probably 2.3). Without this future statement, 'yield' remains an
1614 ordinary identifier, but a warning is issued each time it is used.
1615 (These warnings currently don't conform to the warnings framework of
1616 PEP 230; we intend to fix this in 2.2a2.)
1617
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001618- The UTF-16 codec was modified to be more RFC compliant. It will now
1619 only remove BOM characters at the start of the string and then
1620 only if running in native mode (UTF-16-LE and -BE won't remove a
1621 leading BMO character).
1622
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001623- Strings now have a new method .decode() to complement the already
1624 existing .encode() method. These two methods provide direct access
1625 to the corresponding decoders and encoders of the registered codecs.
1626
1627 To enhance the usability of the .encode() method, the special
1628 casing of Unicode object return values was dropped (Unicode objects
1629 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001630
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001631 Both methods will now return whatever the codec in charge of the
1632 requested encoding returns as object, e.g. Unicode codecs will
1633 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1634 will return u"äöü"). This enables codec writer to create codecs
1635 for various simple to use conversions.
1636
1637 New codecs were added to demonstrate these new features (the .encode()
1638 and .decode() columns indicate the type of the returned objects):
1639
1640 Name | .encode() | .decode() | Description
1641 ----------------------------------------------------------------------
1642 uu | string | string | UU codec (e.g. for email)
1643 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001644 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001645 zlib | string | string | zlib compression
1646 hex | string | string | 2-byte hex codec
1647 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1648
Mark Hammond2a0af792001-05-14 03:09:36 +00001649- Some operating systems now support the concept of a default Unicode
1650 encoding for file system operations. Notably, Windows supports 'mbcs'
1651 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001652 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001653 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001654
1655 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001656 functions that return filenames (such as os.listdir()) to return Python
1657 string objects pre-encoded using the default file system encoding for
1658 the platform. As this encoding is likely to be different from Python's
1659 default encoding, converting this name to a Unicode object before passing
1660 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001661 would attempt to use its default encoding (generally ASCII) rather than
1662 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001663
Tim Petersa814db52001-05-14 07:05:58 +00001664 In general, this change simply removes surprises when working with
1665 Unicode and the file system, making these operations work as you expect,
1666 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001667 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001668
Tim Peters61dff2b2001-05-08 15:43:37 +00001669- Float (and complex) literals in source code were evaluated to full
1670 precision only when running from a .py file; the same code loaded from a
1671 .pyc (or .pyo) file could suffer numeric differences starting at about the
1672 12th significant decimal digit. For example, on a machine with IEEE-754
1673 floating arithmetic,
1674
1675 x = 9007199254740992.0
1676 print long(x)
1677
1678 printed 9007199254740992 if run directly from .py, but 9007199254740000
1679 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1680 str(float) instead of repr(float) when building code objects. marshal
1681 now uses repr(float) instead, which should reproduce floats to full
1682 machine precision (assuming the platform C float<->string I/O conversion
1683 functions are of good quality).
1684
1685 This may cause floating-point results to change in some cases, and
1686 usually for the better, but may also cause numerically unstable
1687 algorithms to break.
1688
Tim Peters2f228e72001-05-13 00:19:31 +00001689- The implementation of dicts suffers fewer collisions, which has speed
1690 benefits. However, the order in which dict entries appear in dict.keys(),
1691 dict.values() and dict.items() may differ from previous releases for a
1692 given dict. Nothing is defined about this order, so no program should
1693 rely on it. Nevertheless, it's easy to write test cases that rely on the
1694 order by accident, typically because of printing the str() or repr() of a
1695 dict to an "expected results" file. See Lib/test/test_support.py's new
1696 sortdict(dict) function for a simple way to display a dict in sorted
1697 order.
1698
Tim Peters7a3bfc32001-06-12 01:22:22 +00001699- Many other small changes to dicts were made, resulting in faster
1700 operation along the most common code paths.
1701
Guido van Rossum10315822001-05-01 20:54:30 +00001702- Dictionary objects now support the "in" operator: "x in dict" means
1703 the same as dict.has_key(x).
1704
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001705- The update() method of dictionaries now accepts generic mapping
1706 objects. Specifically the argument object must support the .keys()
1707 and __getitem__() methods. This allows you to say, for example,
1708 {}.update(UserDict())
1709
Guido van Rossum10315822001-05-01 20:54:30 +00001710- Iterators were added; this is a generalized way of providing values
1711 to a for loop. See PEP 234. There's a new built-in function iter()
1712 to return an iterator. There's a new protocol to get the next value
1713 from an iterator using the next() method (in Python) or the
1714 tp_iternext slot (in C). There's a new protocol to get iterators
1715 using the __iter__() method (in Python) or the tp_iter slot (in C).
1716 Iterating (i.e. a for loop) over a dictionary generates its keys.
1717 Iterating over a file generates its lines.
1718
Tim Petersf553f892001-05-01 20:45:31 +00001719- The following functions were generalized to work nicely with iterator
1720 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001721 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001722 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1723 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001724 join() method of strings
1725 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001726 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1727 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001728 right-hand side of assignment statements with multiple targets, such as
1729 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001730
Tim Petersd85e1022001-05-11 21:51:48 +00001731- Accessing module attributes is significantly faster (for example,
1732 random.random or os.path or yourPythonModule.yourAttribute).
1733
Tim Peterse63415e2001-05-08 04:38:29 +00001734- Comparing dictionary objects via == and != is faster, and now works even
1735 if the keys and values don't support comparisons other than ==.
1736
Tim Peters95bf9392001-05-10 08:32:44 +00001737- Comparing dictionaries in ways other than == and != is slower: there were
1738 insecurities in the dict comparison implementation that could cause Python
1739 to crash if the element comparison routines for the dict keys and/or
1740 values mutated the dicts. Making the code bulletproof slowed it down.
1741
Tim Peterseb28ef22001-06-02 05:27:19 +00001742- Collisions in dicts are resolved via a new approach, which can help
1743 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001744 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001745 faster now. Thanks to Christian Tismer for pointing out the cause and
1746 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001747
Tim Peters52e155e2001-06-16 05:42:57 +00001748- repr() is much faster for large containers (dict, list, tuple).
1749
1750
Tim Petersa814db52001-05-14 07:05:58 +00001751Library
1752
Fred Drake960fdf92001-07-20 18:38:26 +00001753- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1754 were added to the string module. These a locale-indenpendent
1755 constants, unlike letters, lowercase, and uppercase. These are now
1756 use in appropriate locations in the standard library.
1757
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001758- The flags used in dlopen calls can now be configured using
1759 sys.setdlopenflags and queried using sys.getdlopenflags.
1760
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001761- Fredrik Lundh's xmlrpclib is now a standard library module. This
1762 provides full client-side XML-RPC support. In addition,
1763 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1764 one asyncore-based). Thanks to Eric Raymond for the documentation.
1765
Guido van Rossum643d3912001-07-05 14:46:25 +00001766- The xrange() object is simplified: it no longer supports slicing,
1767 repetition, comparisons, efficient 'in' checking, the tolist()
1768 method, or the start, stop and step attributes. See PEP 260.
1769
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001770- A new function fnmatch.filter to filter lists of file names was added.
1771
Barry Warsawffd674d2001-05-22 16:00:10 +00001772- calendar.py uses month and day names based on the current locale.
1773
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001774- strop is now *really* obsolete (this was announced before with 1.6),
1775 and issues DeprecationWarning when used (except for the four items
1776 that are still imported into string.py).
1777
Tim Petersa814db52001-05-14 07:05:58 +00001778- Cookie.py now sorts key+value pairs by key in output strings.
1779
1780- pprint.isrecursive(object) didn't correctly identify recursive objects.
1781 Now it does.
1782
Tim Peters95b3f782001-05-14 18:39:41 +00001783- pprint functions now much faster for large containers (tuple, list, dict).
1784
Tim Peters7b9542a2001-06-10 23:40:19 +00001785- New 'q' and 'Q' format codes in the struct module, corresponding to C
1786 types "long long" and "unsigned long long" (on Windows, __int64). In
1787 native mode, these can be used only when the platform C compiler supports
1788 these types (when HAVE_LONG_LONG is #define'd by the Python config
1789 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001790 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1791 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001792
Guido van Rossum83213cc2001-06-12 16:48:52 +00001793- The site module installs a new built-in function 'help' that invokes
1794 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1795 it displays a message reminding the user to use 'help()' or
1796 'help(object)'.
1797
Tim Petersa814db52001-05-14 07:05:58 +00001798Tests
1799
1800- New test_mutants.py runs dict comparisons where the key and value
1801 comparison operators mutute the dicts randomly during comparison. This
1802 rapidly causes Python to crash under earlier releases (not for the faint
1803 of heart: it can also cause Win9x to freeze or reboot!).
1804
1805- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001806 pprint.isreadable() return sensible results. Also verifies that simple
1807 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001808
Tim Peters4324aa32001-05-28 22:30:08 +00001809C API
1810
1811- Removed the unused last_is_sticky argument from the internal
1812 _PyTuple_Resize(). If this affects you, you were cheating.
1813
1814
Guido van Rossum55a78992001-07-17 17:22:32 +00001815======================================================================
1816
1817
Guido van Rossumffe13be2001-04-16 18:46:45 +00001818What's New in Python 2.1 (final)?
1819=================================
1820
1821We only changed a few things since the last release candidate, all in
1822Python library code:
1823
1824- A bug in the locale module was fixed that affected locales which
1825 define no grouping for numeric formatting.
1826
1827- A few bugs in the weakref module's implementations of weak
1828 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1829 and the test suite was updated to check for these bugs.
1830
1831- An old bug in the os.path.walk() function (introduced in Python
1832 2.0!) was fixed: a non-existent file would cause an exception
1833 instead of being ignored.
1834
1835- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1836 PyChecker.
1837
1838
Guido van Rossum5b08f132001-04-16 02:05:23 +00001839What's New in Python 2.1c2?
1840===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001841
Guido van Rossum5b08f132001-04-16 02:05:23 +00001842A flurry of small changes, and one showstopper fixed in the nick of
1843time made it necessary to release another release candidate. The list
1844here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001845
Guido van Rossum5b08f132001-04-16 02:05:23 +00001846Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001847
Guido van Rossum5b08f132001-04-16 02:05:23 +00001848- Tim discovered a nasty bug in the dictionary code, caused by
1849 PyDict_Next() calling dict_resize(), and the GC code's use of
1850 PyDict_Next() violating an assumption in dict_items(). This was
1851 fixed with considerable amounts of band-aid, but the net effect is a
1852 saner and more robust implementation.
1853
1854- Made a bunch of symbols static that were accidentally global.
1855
1856Build and Ports
1857
1858- The setup.py script didn't check for a new enough version of zlib
1859 (1.1.3 is needed). Now it does.
1860
1861- Changed "make clean" target to also remove shared libraries.
1862
1863- Added a more general warning about the SGI Irix optimizer to README.
1864
1865Library
1866
1867- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1868 omitted the slash between host and file.html.
1869
1870- The mailbox module's _Mailbox class contained a completely broken
1871 and undocumented seek() method. Ripped it out.
1872
1873- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1874 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1875
1876- Fixed a few last-minute bugs in unittest.
1877
1878Extensions
1879
1880- Reverted the patch to the OpenSSL code in socketmodule.c to support
1881 RAND_status() and the EGD, and the subsequent patch that tried to
1882 fix it for pre-0.9.5 versions; the problem with the patch is that on
1883 some systems it issues a warning whenever socket is imported, and
1884 that's unacceptable.
1885
1886Tests
1887
1888- Fixed the pickle tests to work with "import test.test_pickle".
1889
1890- Tweaked test_locale.py to actually run the test Windows.
1891
1892- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1893 not "wb" (which is not a valid mode at all).
1894
1895- Fix pstats browser crashes. Import readline if it exists to make
1896 the user interface nicer.
1897
1898- Add "import thread" to the top of test modules that import the
1899 threading module (test_asynchat and test_threadedtempfile). This
1900 prevents test failures caused by a broken threading module resulting
1901 from a previously caught failed import.
1902
1903- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1904 needed on some platforms (e.g. Solaris 8) when the tests are run
1905 twice in succession.
1906
1907- Skip rather than fail test_sunaudiodev if no audio device is found.
1908
1909
1910What's New in Python 2.1c1?
1911===========================
1912
1913This list was significantly updated when 2.1c2 was released; the 2.1c1
1914release didn't mention most changes that were actually part of 2.1c1:
1915
1916Legal
1917
1918- Copyright was assigned to the Python Software Foundation (PSF) and a
1919 PSF license (very similar to the CNRI license) was added.
1920
1921- The CNRI copyright notice was updated to include 2001.
1922
1923Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001924
Guido van Rossumc9932722001-04-12 02:31:27 +00001925- After a public outcry, assignment to __debug__ is no longer illegal;
1926 instead, a warning is issued. It will become illegal in 2.2.
1927
Guido van Rossum5b08f132001-04-16 02:05:23 +00001928- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1929 "%#x" now always prepends "0x", even if the value is zero.
1930
1931- Fixed some nits in the bytecode compiler.
1932
1933- Fixed core dumps when calling certain kinds of non-functions.
1934
1935- Fixed various core dumps caused by reference count bugs.
1936
1937Build and Ports
1938
1939- Use INSTALL_SCRIPT to install script files.
1940
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001941- New port: SCO Unixware 7, by Billy G. Allie.
1942
Guido van Rossum5b08f132001-04-16 02:05:23 +00001943- Updated RISCOS port.
1944
1945- Updated BeOS port and notes.
1946
1947- Various other porting problems resolved.
1948
1949Library
1950
1951- The TERMIOS and SOCKET modules are now truly obsolete and
1952 unnecessary. Their symbols are incorporated in the termios and
1953 socket modules.
1954
1955- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1956 better tests for pickling.
1957
1958- threading: make Condition.wait() robust against KeyboardInterrupt.
1959
1960- zipfile: add support to zipfile to support opening an archive
1961 represented by an open file rather than a file name. Fix bug where
1962 the archive was not properly closed. Fixed a bug in this bugfix
1963 where flush() was called for a read-only file.
1964
1965- imputil: added an uninstall() method to the ImportManager.
1966
1967- Canvas: fixed bugs in lower() and tkraise() methods.
1968
1969- SocketServer: API change (added overridable close_request() method)
1970 so that the TCP server can explicitly close the request.
1971
1972- pstats: Eric Raymond added a simple interactive statistics browser,
1973 invoked when the module is run as a script.
1974
1975- locale: fixed a problem in format().
1976
1977- webbrowser: made it work when the BROWSER environment variable has a
1978 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1979 KDE 2. Fixed some other nits.
1980
1981- unittest: changes to allow using a different exception than
1982 AssertionError, and added a few more function aliases. Some other
1983 small changes.
1984
1985- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1986
1987- asynchat: fixed a critical bug in asynchat that slipped through the
1988 2.1b2 release. Fixed another rare bug.
1989
1990- Fix some unqualified except: clauses (always a bad code example).
1991
1992XML
1993
1994- pyexpat: new API get_version_string().
1995
1996- Fixed some minidom bugs.
1997
1998Extensions
1999
2000- Fixed a core dump in _weakref. Removed the weakref.mapping()
2001 function (it adds nothing to the API).
2002
2003- Rationalized the use of header files in the readline module, to make
2004 it compile (albeit with some warnings) with the very recent readline
2005 4.2, without breaking for earlier versions.
2006
2007- Hopefully fixed a buffering problem in linuxaudiodev.
2008
2009- Attempted a fix to make the OpenSSL support in the socket module
2010 work again with pre-0.9.5 versions of OpenSSL.
2011
2012Tests
2013
2014- Added a test case for asynchat and asyncore.
2015
2016- Removed coupling between tests where one test failing could break
2017 another.
2018
2019Tools
2020
2021- Ping added an interactive help browser to pydoc, fixed some nits
2022 in the rest of the pydoc code, and added some features to his
2023 inspect module.
2024
2025- An updated python-mode.el version 4.1 which integrates Ken
2026 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2027 much nicer in XEmacs and Emacs. When stepping through your program
2028 with pdb, in either the shell window or the *Python* window, the
2029 source file and line will be tracked by an arrow. Very cool!
2030
2031- IDLE: syntax warnings in interactive mode are changed into errors.
2032
2033- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002034 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002035
2036- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002037
Barry Warsaw11e89c72001-04-11 20:37:57 +00002038
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002039What's New in Python 2.1 beta 2?
2040================================
2041
Guido van Rossum053ae352001-03-22 14:17:21 +00002042(Unlisted are many fixed bugs, more documentation, etc.)
2043
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002044Core language, builtins, and interpreter
2045
Guido van Rossum053ae352001-03-22 14:17:21 +00002046- The nested scopes work (enabled by "from __future__ import
2047 nested_scopes") is completed; in particular, the future now extends
2048 into code executed through exec, eval() and execfile(), and into the
2049 interactive interpreter.
2050
2051- When calling a base class method (e.g. BaseClass.__init__(self)),
2052 this is now allowed even if self is not strictly spoken a class
2053 instance (e.g. when using metaclasses or the Don Beaudry hook).
2054
2055- Slice objects are now comparable but not hashable; this prevents
2056 dict[:] from being accepted but meaningless.
2057
2058- Complex division is now calculated using less braindead algorithms.
2059 This doesn't change semantics except it's more likely to give useful
2060 results in extreme cases. Complex repr() now uses full precision
2061 like float repr().
2062
2063- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2064
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002065- It is illegal to assign to the name __debug__, which is set when the
2066 interpreter starts. It is effectively a compile-time constant.
2067
2068- A warning will be issued if a global statement for a variable
2069 follows a use or assignment of that variable.
2070
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002071Standard library
2072
Guido van Rossum053ae352001-03-22 14:17:21 +00002073- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2074 inspired by JUnit), is now part of the standard library. You now
2075 have a choice of two testing frameworks: unittest requires you to
2076 write testcases as separate code, doctest gathers them from
2077 docstrings. Both approaches have their advantages and
2078 disadvantages.
2079
2080- A new module Tix was added, which wraps the Tix extension library
2081 for Tk. With that module, it is not necessary to statically link
2082 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2083 require" command. See Demo/tix/.
2084
2085- tzparse.py is now obsolete.
2086
2087- In gzip.py, the seek() and tell() methods are removed -- they were
2088 non-functional anyway, and it's better if callers can test for their
2089 existence with hasattr().
2090
2091Python/C API
2092
2093- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2094 that's already in the dictionary during a PyDict_Next() iteration.
2095 This used to fail occasionally when a dictionary resize operation
2096 could be triggered that would rehash all the keys. All other
2097 modifications to the dictionary are still off-limits during a
2098 PyDict_Next() iteration!
2099
2100- New extended APIs related to passing compiler variables around.
2101
2102- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2103 implement isinstance() and issubclass().
2104
2105- Py_BuildValue() now has a "D" conversion to create a Python complex
2106 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002107
Fred Drake4e262a92001-03-22 18:26:47 +00002108- Extensions types which support weak references must now set the
2109 field allocated for the weak reference machinery to NULL themselves;
2110 this is done to avoid the cost of checking each object for having a
2111 weakly referencable type in PyObject_INIT(), since most types are
2112 not weakly referencable.
2113
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002114- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2115 free variables and cell variables to and from the frame's f_locals.
2116
2117- Variants of several functions defined in pythonrun.h have been added
2118 to support the nested_scopes future statement. The variants all end
2119 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2120 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2121 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002122 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002123
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002124Distutils
2125
2126- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2127 into the release tree.
2128
Tim Peters0e57abf2001-05-02 07:39:38 +00002129- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002130 (an uninstaller, more customization of the installer's display)
2131
2132- from Jack Jansen: added Mac-specific code to generate a dialog for
2133 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002134 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002135 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002136
2137- added 'platforms' and 'keywords' to the set of metadata that can be
2138 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002139
2140- applied patches from Jason Tishler to make the compiler class work with
2141 Cygwin.
2142
2143
Tim Peters2fe289a2001-03-01 22:19:38 +00002144What's New in Python 2.1 beta 1?
2145================================
Tim Petersd66595f2001-02-04 03:09:53 +00002146
2147Core language, builtins, and interpreter
2148
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002149- Following an outcry from the community about the amount of code
2150 broken by the nested scopes feature introduced in 2.1a2, we decided
2151 to make this feature optional, and to wait until Python 2.2 (or at
2152 least 6 months) to make it standard. The option can be enabled on a
2153 per-module basis by adding "from __future__ import nested_scopes" at
2154 the beginning of a module (before any other statements, but after
2155 comments and an optional docstring). See PEP 236 (Back to the
2156 __future__) for a description of the __future__ statement. PEP 227
2157 (Statically Nested Scopes) has been updated to reflect this change,
2158 and to clarify the semantics in a number of endcases.
2159
2160- The nested scopes code, when enabled, has been hardened, and most
2161 bugs and memory leaks in it have been fixed.
2162
2163- Compile-time warnings are now generated for a number of conditions
2164 that will break or change in meaning when nested scopes are enabled:
2165
2166 - Using "from...import *" or "exec" without in-clause in a function
2167 scope that also defines a lambda or nested function with one or
2168 more free (non-local) variables. The presence of the import* or
2169 bare exec makes it impossible for the compiler to determine the
2170 exact set of local variables in the outer scope, which makes it
2171 impossible to determine the bindings for free variables in the
2172 inner scope. To avoid the warning about import *, change it into
2173 an import of explicitly name object, or move the import* statement
2174 to the global scope; to avoid the warning about bare exec, use
2175 exec...in... (a good idea anyway -- there's a possibility that
2176 bare exec will be deprecated in the future).
2177
2178 - Use of a global variable in a nested scope with the same name as a
2179 local variable in a surrounding scope. This will change in
2180 meaning with nested scopes: the name in the inner scope will
2181 reference the variable in the outer scope rather than the global
2182 of the same name. To avoid the warning, either rename the outer
2183 variable, or use a global statement in the inner function.
2184
Neil Schemenauera35c6882001-02-27 04:45:05 +00002185- An optional object allocator has been included. This allocator is
2186 optimized for Python objects and should be faster and use less memory
2187 than the standard system allocator. It is not enabled by default
2188 because of possible thread safety problems. The allocator is only
2189 protected by the Python interpreter lock and it is possible that some
2190 extension modules require a thread safe allocator. The object
2191 allocator can be enabled by providing the "--with-pymalloc" option to
2192 configure.
2193
Tim Petersd66595f2001-02-04 03:09:53 +00002194Standard library
2195
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002196- pyexpat now detects the expat version if expat.h defines it. A
2197 number of additional handlers are provided, which are only available
2198 since expat 1.95. In addition, the methods SetParamEntityParsing and
2199 GetInputContext of Parser objects are available with 1.95.x
2200 only. Parser objects now provide the ordered_attributes and
2201 specified_attributes attributes. A new module expat.model was added,
2202 which offers a number of additional constants if 1.95.x is used.
2203
2204- xml.dom offers the new functions registerDOMImplementation and
2205 getDOMImplementation.
2206
2207- xml.dom.minidom offers a toprettyxml method. A number of DOM
2208 conformance issues have been resolved. In particular, Element now
2209 has an hasAttributes method, and the handling of namespaces was
2210 improved.
2211
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002212- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2213 getting information about live Python code, and pydoc.py, a module
2214 for interactively converting docstrings to HTML or text.
2215 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002216 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002217 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2218 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002219
Tim Peters1eff7962001-03-01 02:31:33 +00002220- New library module difflib.py, primarily packaging the SequenceMatcher
2221 class at the heart of the popular ndiff.py file-comparison tool.
2222
2223- doctest.py (a framework for verifying Python code examples in docstrings)
2224 is now part of the std library.
2225
Tim Petersd66595f2001-02-04 03:09:53 +00002226Windows changes
2227
Guido van Rossume3955a82001-03-02 14:05:59 +00002228- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2229 small GUI that lets you browse the module docstrings using your
2230 default web browser.
2231
Tim Peters1eff7962001-03-01 02:31:33 +00002232- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2233 Platforms) is implemented. See
2234
2235 http://python.sourceforge.net/peps/pep-0235.html
2236
2237 for full details, especially the "Current Lower-Left Semantics" section.
2238 The new Windows import rules are simpler than before:
2239
2240 A. If the PYTHONCASEOK environment variable exists, same as
2241 before: silently accept the first case-insensitive match of any
2242 kind; raise ImportError if none found.
2243
2244 B. Else search sys.path for the first case-sensitive match; raise
2245 ImportError if none found.
2246
2247 The same rules have been implented on other platforms with case-
2248 insensitive but case-preserving filesystems too (including Cygwin, and
2249 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002250
Tim Peters25a9ce32001-02-19 07:06:36 +00002251- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2252 what it's supposed to do (and does do under NT and 2000) via direct
2253 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002254 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002255 all Win9x systems before.
2256
Tim Peters1eff7962001-03-01 02:31:33 +00002257- Build: Subproject _test (effectively) renamed to _testcapi.
2258
Tim Peters2fe289a2001-03-01 22:19:38 +00002259New platforms
2260
2261- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2262 Thanks to Steven Majewski!
2263
2264- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2265 Tishler!
2266
Guido van Rossum9089b272001-03-02 06:49:50 +00002267- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2268 Schwertberger! See RISCOS/README for more information -- it seems
2269 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002270 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002271
Tim Peters25a9ce32001-02-19 07:06:36 +00002272
Tim Petersd7b5e882001-01-25 03:36:26 +00002273What's New in Python 2.1 alpha 2?
2274=================================
Tim Peters40ead762001-01-27 05:35:26 +00002275
Tim Petersd7b5e882001-01-25 03:36:26 +00002276Core language, builtins, and interpreter
2277
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002278- Scopes nest. If a name is used in a function or class, but is not
2279 local, the definition in the nearest enclosing function scope will
2280 be used. One consequence of this change is that lambda statements
2281 could reference variables in the namespaces where the lambda is
2282 defined. In some unusual cases, this change will break code.
2283
2284 In all previous version of Python, names were resolved in exactly
2285 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002286 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002287 function A is defined within a function B, the names bound in B are
2288 not visible in A. The new rules make names bound in B visible in A,
2289 unless A contains a name binding that hides the binding in B.
2290
2291 Section 4.1 of the reference manual describes the new scoping rules
2292 in detail. The test script in Lib/test/test_scope.py demonstrates
2293 some of the effects of the change.
2294
2295 The new rules will cause existing code to break if it defines nested
2296 functions where an outer function has local variables with the same
2297 name as globals or builtins used by the inner function. Example:
2298
2299 def munge(str):
2300 def helper(x):
2301 return str(x)
2302 if type(str) != type(''):
2303 str = helper(str)
2304 return str.strip()
2305
2306 Under the old rules, the name str in helper() is bound to the
2307 builtin function str(). Under the new rules, it will be bound to
2308 the argument named str and an error will occur when helper() is
2309 called.
2310
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002311- The compiler will report a SyntaxError if "from ... import *" occurs
2312 in a function or class scope. The language reference has documented
2313 that this case is illegal, but the compiler never checked for it.
2314 The recent introduction of nested scope makes the meaning of this
2315 form of name binding ambiguous. In a future release, the compiler
2316 may allow this form when there is no possibility of ambiguity.
2317
Tim Peters40ead762001-01-27 05:35:26 +00002318- repr(string) is easier to read, now using hex escapes instead of octal,
2319 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2320
2321 >>> "\texample \r\n" + chr(0) + chr(255)
2322 '\texample \r\n\x00\xff' # in 2.1
2323 '\011example \015\012\000\377' # in 2.0
2324
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002325- Functions are now compared and hashed by identity, not by value, since
2326 the func_code attribute is writable.
2327
Fred Drakefb9d7122001-02-01 20:00:40 +00002328- Weak references (PEP 205) have been added. This involves a few
2329 changes in the core, an extension module (_weakref), and a Python
2330 module (weakref). The weakref module is the public interface. It
2331 includes support for "explicit" weak references, proxy objects, and
2332 mappings with weakly held values.
2333
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002334- A 'continue' statement can now appear in a try block within the body
2335 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002336 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002337
Tim Petersd7b5e882001-01-25 03:36:26 +00002338Standard library
2339
Barry Warsaw30dbd142001-01-31 22:14:01 +00002340- mailbox.py now has a new class, PortableUnixMailbox which is
2341 identical to UnixMailbox but uses a more portable scheme for
2342 determining From_ separators. Also, the constructors for all the
2343 classes in this module have a new optional `factory' argument, which
2344 is a callable used when new message classes must be instantiated by
2345 the next() method.
2346
Tim Petersd7b5e882001-01-25 03:36:26 +00002347- random.py is now self-contained, and offers all the functionality of
2348 the now-deprecated whrandom.py. See the docs for details. random.py
2349 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002350 and restoring the internal state of the generator; and jumpahead(n),
2351 for quickly forcing the internal state to be the same as if n calls to
2352 random() had been made. The latter is particularly useful for multi-
2353 threaded programs, creating one instance of the random.Random() class for
2354 each thread, then using .jumpahead() to force each instance to use a
2355 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002356
Tim Peters0de88fc2001-02-01 04:59:18 +00002357- random.py's seed() function is new. For bit-for-bit compatibility with
2358 prior releases, use the whseed function instead. The new seed function
2359 addresses two problems: (1) The old function couldn't produce more than
2360 about 2**24 distinct internal states; the new one about 2**45 (the best
2361 that can be done in the Wichmann-Hill generator). (2) The old function
2362 sometimes produced identical internal states when passed distinct
2363 integers, and there was no simple way to predict when that would happen;
2364 the new one guarantees to produce distinct internal states for all
2365 arguments in [0, 27814431486576L).
2366
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002367- The socket module now supports raw packets on Linux. The socket
2368 family is AF_PACKET.
2369
Tim Peters9ea17ac2001-02-02 05:57:15 +00002370- test_capi.py is a start at running tests of the Python C API. The tests
2371 are implemented by the new Modules/_testmodule.c.
2372
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002373- A new extension module, _symtable, provides provisional access to the
2374 internal symbol table used by the Python compiler. A higher-level
2375 interface will be added on top of _symtable in a future release.
2376
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002377- Removed the obsolete soundex module.
2378
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002379- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2380 the isSameNode method; NamedNodeMap the get method.
2381
2382- xml.sax.expatreader supports the lexical handler property; it
2383 generates comment, startCDATA, and endCDATA events.
2384
Tim Petersee826f82001-01-31 19:39:44 +00002385Windows changes
2386
2387- Build procedure: the zlib project is built in a different way that
2388 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002389 the zlib binary used. See PCbuild\readme.txt for details. Your old
2390 zlib-related directories can be deleted; you'll need to download fresh
2391 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002392
Tim Peters9ea17ac2001-02-02 05:57:15 +00002393- Build: New subproject _test for the benefit of test_capi.py (see above).
2394
Tim Petersb16c56f2001-02-02 21:24:51 +00002395- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2396 interface to some Python compiler internals).
2397
2398- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002399 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002400
Tim Petersa3a3a032000-11-30 05:22:44 +00002401What's New in Python 2.1 alpha 1?
2402=================================
2403
2404Core language, builtins, and interpreter
2405
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002406- There is a new Unicode companion to the PyObject_Str() API
2407 called PyObject_Unicode(). It behaves in the same way as the
2408 former, but assures that the returned value is an Unicode object
2409 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002410
Guido van Rossumf98eda02001-01-17 15:54:45 +00002411- The comparison operators support "rich comparison overloading" (PEP
2412 207). C extension types can provide a rich comparison function in
2413 the new tp_richcompare slot in the type object. The cmp() function
2414 and the C function PyObject_Compare() first try the new rich
2415 comparison operators before trying the old 3-way comparison. There
2416 is also a new C API PyObject_RichCompare() (which also falls back on
2417 the old 3-way comparison, but does not constrain the outcome of the
2418 rich comparison to a Boolean result).
2419
2420 The rich comparison function takes two objects (at least one of
2421 which is guaranteed to have the type that provided the function) and
2422 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2423 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2424 object, which may be NotImplemented (in which case the tp_compare
2425 slot function is used as a fallback, if defined).
2426
2427 Classes can overload individual comparison operators by defining one
2428 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002429 __ge__. There are no explicit "reflected argument" versions of
2430 these; instead, __lt__ and __gt__ are each other's reflection,
2431 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2432 reflection (similar at the C level). No other implications are
2433 made; in particular, Python does not assume that == is the Boolean
2434 inverse of !=, or that < is the Boolean inverse of >=. This makes
2435 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002436
2437 Classes or types that want to implement (in)equality tests but not
2438 the ordering operators (i.e. unordered types) should implement ==
2439 and !=, and raise an error for the ordering operators.
2440
Guido van Rossuma88479f2001-01-18 14:28:08 +00002441 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002442 Boolean; e.g. a matrix type might want to return a matrix of bits
2443 for A < B, giving elementwise comparisons. Such types should ensure
2444 that any interpretation of their value in a Boolean context raises
2445 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2446 at the C level) to always raise an exception.
2447
Guido van Rossuma88479f2001-01-18 14:28:08 +00002448- Complex numbers use rich comparisons to define == and != but raise
2449 an exception for <, <=, > and >=. Unfortunately, this also means
2450 that cmp() of two complex numbers raises an exception when the two
2451 numbers differ. Since it is not mathematically meaningful to compare
2452 complex numbers except for equality, I hope that this doesn't break
2453 too much code.
2454
Tim Peters3389f192001-02-18 08:48:49 +00002455- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002456 not defined by the language, other than that it's arbitrary but
2457 consistent (see the Reference Manual). An implementation detail changed
2458 in 2.1a1 such that None now compares less than any other object. Code
2459 relying on this new behavior (like code that relied on the previous
2460 behavior) does so at its own risk.
2461
Barry Warsaw573b5412001-01-15 20:43:18 +00002462- Functions and methods now support getting and setting arbitrarily
2463 named attributes (PEP 232). Functions have a new __dict__
2464 (a.k.a. func_dict) which hold the function attributes. Methods get
2465 and set attributes on their underlying im_func. It is a TypeError
2466 to set an attribute on a bound method.
2467
Guido van Rossum051e3352001-01-15 19:11:10 +00002468- The xrange() object implementation has been improved so that
2469 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2470 limitation that in this case len(xrange(sys.maxint)) can't be
2471 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2472 work fine as long as the index i doesn't actually reach 2**31.
2473 (Python uses regular ints for sequence and string indices; fixing
2474 that is much more work.)
2475
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002476- Two changes to from...import:
2477
Guido van Rossumba381232001-02-03 15:06:40 +00002478 1) "from M import X" now works even if (after loading module M)
2479 sys.modules['M'] is not a real module; it's basically a getattr()
2480 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002481
2482 2) "from M import *" now looks for M.__all__ to decide which names to
2483 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2484 filters out names starting with '_' as before. Whether or not
2485 __all__ exists, there's no restriction on the type of M.
2486
Guido van Rossumf61f1662001-01-10 20:13:55 +00002487- File objects have a new method, xreadlines(). This is the fastest
2488 way to iterate over all lines in a file:
2489
2490 for line in file.xreadlines():
2491 ...do something to line...
2492
2493 See the xreadlines module (mentioned below) for how to do this for
2494 other file-like objects.
2495
2496- Even if you don't use file.xreadlines(), you may expect a speedup on
2497 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002498 quite a bit in platform-specific ways: on systems (like Linux) that
2499 support flockfile(), getc_unlocked(), and funlockfile(), those are
2500 used by default. On systems (like Windows) without getc_unlocked(),
2501 a complicated (but still thread-safe) method using fgets() is used by
2502 default.
2503
Tim Petersd52269b2001-01-25 06:23:18 +00002504 You can force use of the fgets() method by #define'ing
2505 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002506 getc_unlocked()).
2507
Tim Petersd52269b2001-01-25 06:23:18 +00002508 You can force fgets() not to be used by #define'ing
2509 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002510 test_bufio.py fails -- and let us know if it does!).
2511
2512- In addition, the fileinput module, while still slower than the other
2513 methods on most platforms, has been sped up too, by using
2514 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002515
2516- Support for run-time warnings has been added, including a new
2517 command line option (-W) to specify the disposition of warnings.
2518 See the description of the warnings module below.
2519
2520- Extensive changes have been made to the coercion code. This mostly
2521 affects extension modules (which can now implement mixed-type
2522 numerical operators without having to use coercion), but
2523 occasionally, in boundary cases the coercion semantics have changed
2524 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002525 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002526 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002527 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002528
Guido van Rossumf98eda02001-01-17 15:54:45 +00002529- In connection with the coercion changes, a new built-in singleton
2530 object, NotImplemented is defined. This can be returned for
2531 operations that wish to indicate they are not implemented for a
2532 particular combination of arguments. From C, this is
2533 Py_NotImplemented.
2534
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002535- The interpreter accepts now bytecode files on the command line even
2536 if they do not have a .pyc or .pyo extension. On Linux, after executing
2537
Martin v. Löwise214baa2001-02-04 22:37:56 +00002538import imp,sys,string
2539magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2540reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2541open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002542
2543 any byte code file can be used as an executable (i.e. as an argument
2544 to execve(2)).
2545
Tim Peters9940b802000-12-01 07:59:35 +00002546- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002547 character. In 1.6 and earlier, they never produced a sign,
2548 and raised an error if the value of the long was too large
2549 to fit in a Python int. In 2.0, they produced a sign if and
2550 only if too large to fit in an int. This was inconsistent
2551 across platforms (because the size of an int varies across
2552 platforms), and inconsistent with hex() and oct(). Example:
2553
2554 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002555 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002556 'ffffffbe' # in 2.0 and before, on 32-bit machines
2557 >>> hex(-0x42L)
2558 '-0x42L' # in all versions of Python
2559
Tim Peters9940b802000-12-01 07:59:35 +00002560 The behavior of %d formats for negative Python longs remains
2561 the same as in 2.0 (although in 1.6 and before, they raised
2562 an error if the long didn't fit in a Python int).
2563
2564 %u formats don't make sense for Python longs, but are allowed
2565 and treated the same as %d in 2.1. In 2.0, a negative long
2566 formatted via %u produced a sign if and only if too large to
2567 fit in an int. In 1.6 and earlier, a negative long formatted
2568 via %u raised an error if it was too big to fit in an int.
2569
Guido van Rossum3661d392000-12-12 22:10:31 +00002570- Dictionary objects have an odd new method, popitem(). This removes
2571 an arbitrary item from the dictionary and returns it (in the form of
2572 a (key, value) pair). This can be useful for algorithms that use a
2573 dictionary as a bag of "to do" items and repeatedly need to pick one
2574 item. Such algorithms normally end up running in quadratic time;
2575 using popitem() they can usually be made to run in linear time.
2576
Tim Peters36cdad12000-12-29 02:06:45 +00002577Standard library
2578
Thomas Woutersfe385252001-01-19 23:16:56 +00002579- In the time module, the time argument to the functions strftime,
2580 localtime, gmtime, asctime and ctime is now optional, defaulting to
2581 the current time (in the local timezone).
2582
Guido van Rossumda91f222001-01-15 16:36:08 +00002583- The ftplib module now defaults to passive mode, which is deemed a
2584 more useful default given that clients are often inside firewalls
2585 these days. Note that this could break if ftplib is used to connect
2586 to a *server* that is inside a firewall, from outside; this is
2587 expected to be a very rare situation. To fix that, you can call
2588 ftp.set_pasv(0).
2589
Martin v. Löwis10a27872001-01-13 09:54:41 +00002590- The module site now treats .pth files not only for path configuration,
2591 but also supports extensions to the initialization code: Lines starting
2592 with import are executed.
2593
Guido van Rossumf61f1662001-01-10 20:13:55 +00002594- There's a new module, warnings, which implements a mechanism for
2595 issuing and filtering warnings. There are some new built-in
2596 exceptions that serve as warning categories, and a new command line
2597 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2598 turns warnings into errors). warnings.warn(message[, category])
2599 issues a warning message; this can also be called from C as
2600 PyErr_Warn(category, message).
2601
2602- A new module xreadlines was added. This exports a single factory
2603 function, xreadlines(). The intention is that this code is the
2604 absolutely fastest way to iterate over all lines in an open
2605 file(-like) object:
2606
2607 import xreadlines
2608 for line in xreadlines.xreadlines(file):
2609 ...do something to line...
2610
2611 This is equivalent to the previous the speed record holder using
2612 file.readlines(sizehint). Note that if file is a real file object
2613 (as opposed to a file-like object), this is equivalent:
2614
2615 for line in file.xreadlines():
2616 ...do something to line...
2617
Tim Peters36cdad12000-12-29 02:06:45 +00002618- The bisect module has new functions bisect_left, insort_left,
2619 bisect_right and insort_right. The old names bisect and insort
2620 are now aliases for bisect_right and insort_right. XXX_right
2621 and XXX_left methods differ in what happens when the new element
2622 compares equal to one or more elements already in the list: the
2623 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002624 right. Code that doesn't care where equal elements end up should
2625 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002626
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002627- The new curses.panel module wraps the panel library that forms part
2628 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2629
Guido van Rossumf61f1662001-01-10 20:13:55 +00002630- The SocketServer module now sets the allow_reuse_address flag by
2631 default in the TCPServer class.
2632
2633- A new function, sys._getframe(), returns the stack frame pointer of
2634 the caller. This is intended only as a building block for
2635 higher-level mechanisms such as string interpolation.
2636
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002637- The pyexpat module supports a number of new handlers, which are
2638 available only in expat 1.2. If invocation of a callback fails, it
2639 will report an additional frame in the traceback. Parser objects
2640 participate now in garbage collection. If expat reports an unknown
2641 encoding, pyexpat will try to use a Python codec; that works only
2642 for single-byte charsets. The parser type objects is exposed as
2643 XMLParserObject.
2644
2645- xml.dom now offers standard definitions for symbolic node type and
2646 exception code constants, and a hierarchy of DOM exceptions. minidom
2647 was adjusted to use them.
2648
2649- The conformance of xml.dom.minidom to the DOM specification was
2650 improved. It detects a number of additional error cases; the
2651 previous/next relationship works even when the tree is modified;
2652 Node supports the normalize() method; NamedNodeMap, DocumentType and
2653 DOMImplementation classes were added; Element supports the
2654 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2655 method.
2656
Guido van Rossumf61f1662001-01-10 20:13:55 +00002657Build issues
2658
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002659- For Unix (and Unix-compatible) builds, configuration and building of
2660 extension modules is now greatly automated. Rather than having to
2661 edit the Modules/Setup file to indicate which modules should be
2662 built and where their include files and libraries are, a
2663 distutils-based setup.py script now takes care of building most
2664 extension modules. All extension modules built this way are built
2665 as shared libraries. Only a few modules that must be linked
2666 statically are still listed in the Setup file; you won't need to
2667 edit their configuration.
2668
2669- Python should now build out of the box on Cygwin. If it doesn't,
2670 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002671
2672- Python now always uses its own (renamed) implementation of getopt()
2673 -- there's too much variation among C library getopt()
2674 implementations.
2675
2676- C++ compilers are better supported; the CXX macro is always set to a
2677 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002678
Tim Petersd92dfe02000-12-12 01:18:41 +00002679Windows changes
2680
2681- select module: By default under Windows, a select() call
2682 can specify no more than 64 sockets. Python now boosts
2683 this Microsoft default to 512. If you need even more than
2684 that, see the MS docs (you'll need to #define FD_SETSIZE
2685 and recompile Python from source).
2686
Guido van Rossumf61f1662001-01-10 20:13:55 +00002687- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2688 subdirectory is no more!
2689
Tim Petersa3a3a032000-11-30 05:22:44 +00002690
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002691What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002692=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002693
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002694Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002695changes are in the file HISTORY. If you are making the jump directly
2696from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2697HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002698
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002699Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2700the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2701http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002702
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002703--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002704
2705======================================================================
2706
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002707What's new in 2.0 (since release candidate 1)?
2708==============================================
2709
2710Standard library
2711
2712- The copy_reg module was modified to clarify its intended use: to
2713 register pickle support for extension types, not for classes.
2714 pickle() will raise a TypeError if it is passed a class.
2715
2716- Fixed a bug in gettext's "normalize and expand" code that prevented
2717 it from finding an existing .mo file.
2718
2719- Restored support for HTTP/0.9 servers in httplib.
2720
Tim Peters989b7b92000-10-16 20:24:53 +00002721- The math module was changed to stop raising OverflowError in case of
2722 underflow, and return 0 instead in underflow cases. Whether Python
2723 used to raise OverflowError in case of underflow was platform-
2724 dependent (it did when the platform math library set errno to ERANGE
2725 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002726
2727- Fixed a bug in StringIO that occurred when the file position was not
2728 at the end of the file and write() was called with enough data to
2729 extend past the end of the file.
2730
2731- Fixed a bug that caused Tkinter error messages to get lost on
2732 Windows. The bug was fixed by replacing direct use of
2733 interp->result with Tcl_GetStringResult(interp).
2734
2735- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2736 redirect response.
2737
2738- Several changes were made to distutils: Some debugging code was
2739 removed from util. Fixed the installer used when an external zip
2740 program (like WinZip) is not found; the source code for this
2741 installer is in Misc/distutils. check_lib() was modified to behave
2742 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2743 test for whether installed modules are on sys.path was changed to
2744 use both normcase() and normpath().
2745
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002746- Several minor bugs were fixed in the xml package (the minidom,
2747 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002748
2749- The regression test driver (regrtest.py) behavior when invoked with
2750 -l changed: It now reports a count of objects that are recognized as
2751 garbage but not freed by the garbage collector.
2752
Tim Peters989b7b92000-10-16 20:24:53 +00002753- The regression test for the math module was changed to test
2754 exceptional behavior when the test is run in verbose mode. Python
2755 cannot yet guarantee consistent exception behavior across platforms,
2756 so the exception part of test_math is run only in verbose mode, and
2757 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002758
2759Internals
2760
2761- PyOS_CheckStack() has been disabled on Win64, where it caused
2762 test_sre to fail.
2763
2764Build issues
2765
2766- Changed compiler flags, so that gcc is always invoked with -Wall and
2767 -Wstrict-prototypes. Users compiling Python with GCC should see
2768 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002769 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002770 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002771
Tim Petersa3a3a032000-11-30 05:22:44 +00002772- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002773
2774Tools and other miscellany
2775
2776- The compiler in Tools/compiler was updated to support the new
2777 language features introduced in 2.0: extended print statement, list
2778 comprehensions, and augmented assignments. The new compiler should
2779 also be backwards compatible with Python 1.5.2; the compiler will
2780 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002781 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002782
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002783What's new in 2.0 release candidate 1 (since beta 2)?
2784=====================================================
2785
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002786What is release candidate 1?
2787
2788We believe that release candidate 1 will fix all known bugs that we
2789intend to fix for the 2.0 final release. This release should be a bit
2790more stable than the previous betas. We would like to see even more
2791widespread testing before the final release, so we are producing this
2792release candidate. The final release will be exactly the same unless
2793any show-stopping (or brown bag) bugs are found by testers of the
2794release candidate.
2795
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002796All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002797to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002798
2799Core language, builtins, and interpreter
2800
2801- A bug that caused crashes when __coerce__ was used with augmented
2802 assignment, e.g. +=, was fixed.
2803
2804- Raise ZeroDivisionError when raising zero to a negative number,
2805 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2806 power operator and the result of math.pow(0.0, -2.0) will vary by
2807 platform. On Linux, it raises a ValueError.
2808
2809- A bug in Unicode string interpolation was fixed that occasionally
2810 caused errors with formats including "%%". For example, the
2811 following expression "%% %s" % u"abc" no longer raises a TypeError.
2812
2813- Compilation of deeply nested expressions raises MemoryError instead
2814 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2815
2816- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2817 rendering them useless. They are now written in binary mode again.
2818
2819Standard library
2820
2821- Keyword arguments are now accepted for most pattern and match object
2822 methods in SRE, the standard regular expression engine.
2823
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002824- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002825 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002826
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002827- Several bugs in the Unicode handling and error handling in _tkinter
2828 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002829
2830- Fix memory management errors in Merge() and Tkapp_Call() routines.
2831
2832- Several changes were made to cStringIO to make it compatible with
2833 the file-like object interface and with StringIO. If operations are
2834 performed on a closed object, an exception is raised. The truncate
2835 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002836 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002837
2838- There were many changes made to the linuxaudiodev module and its
2839 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002840 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002841
2842 Note that this module is named poorly, because it should work
2843 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002844 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002845
2846 The module now raises exceptions when errors occur instead of
2847 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2848 audio) and defines a getptr() method that calls the
2849 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2850
2851- The library_version attribute, introduced in an earlier beta, was
2852 removed because it can not be supported with early versions of the C
2853 readline library, which provides no way to determine the version at
2854 compile-time.
2855
2856- The binascii module is now enabled on Win64.
2857
Tim Peters46446d62000-10-09 21:19:31 +00002858- tokenize.py no longer suffers "recursion depth" errors when parsing
2859 programs with very long string literals.
2860
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002861Internals
2862
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002863- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002864 which is called when the interpreter starts up to determine where
2865 the standard library is installed. These vulnerabilities affect all
2866 previous versions of Python and can be exploited by setting very
2867 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2868 setuid Python script, although use of the wrapper in
2869 Misc/setuid-prog.c will eliminate the vulnerability.
2870
2871- Fixed garbage collection bugs in instance creation that were
2872 triggered when errors occurred during initialization. The solution,
2873 applied in cPickle and in PyInstance_New(), is to call
2874 PyObject_GC_Init() after the initialization of the object's
2875 container attributes is complete.
2876
2877- pyexpat adds definitions of PyModule_AddStringConstant and
2878 PyModule_AddObject if the Python version is less than 2.0, which
2879 provides compatibility with PyXML on Python 1.5.2.
2880
2881- If the platform has a bogus definition for LONG_BIT (the number of
2882 bits in a long), an error will be reported at compile time.
2883
2884- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2885 collection crashes and possibly other, unreported crashes.
2886
2887- Fixed a memory leak in _PyUnicode_Fini().
2888
2889Build issues
2890
2891- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002892 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002893 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002894
2895- The mmap.PAGESIZE constant is now initialized using sysconf when
2896 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2897
2898- The md5 file should now compile on all platforms.
2899
2900- The select module now compiles on platforms that do not define
2901 POLLRDNORM and related constants.
2902
2903- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002904 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002905
Jeremy Hylton10921202000-10-09 18:34:12 +00002906- BeOS: A number of changes were made to the build and installation
2907 process. ar-fake now operates on a directory of object files.
2908 dl_export.h is gone, and its macros now appear on the mwcc command
2909 line during build on PPC BeOS.
2910
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002911- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002912 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002913
2914- Cygwin: Support for shared libraries, Tkinter, and sockets.
2915
2916- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2917
2918Tools and other miscellany
2919
2920- Removed debugging prints from main used with freeze.
2921
Tim Peters46446d62000-10-09 21:19:31 +00002922- IDLE auto-indent no longer crashes when it encounters Unicode
2923 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002924
2925What's new in 2.0 beta 2 (since beta 1)?
2926========================================
2927
2928Core language, builtins, and interpreter
2929
Tim Peters482c0212000-09-26 06:33:09 +00002930- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002931 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002932
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002933- Add -h and -V command line options to print the usage message and
2934 Python version number and exit immediately.
2935
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002936- eval() and exec accept Unicode objects as code parameters.
2937
2938- getattr() and setattr() now also accept Unicode objects for the
2939 attribute name, which are converted to strings using the default
2940 encoding before lookup.
2941
2942- Multiplication on string and Unicode now does proper bounds
2943 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2944 string is too long."
2945
2946- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002947 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002948
Jeremy Hylton1b618592000-09-26 05:32:36 +00002949
2950Standard library and extensions
2951
Guido van Rossum5b08f132001-04-16 02:05:23 +00002952- socket module: the OpenSSL code now adds support for RAND_status()
2953 and EGD (Entropy Gathering Device).
2954
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002955- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002956 argument checking; it still takes no arguments.
2957
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002958- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002959
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002960- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002961
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002962- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002963
2964- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002965 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002966
2967- copy: Copy Unicode objects atomically.
2968
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002969- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002970
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002971- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002972
Fred Drake67233bc2000-09-26 16:40:27 +00002973- dbm: Add get() and setdefault() methods to dbm object. Add constant
2974 `library' to module that names the library used. Added doc strings
2975 and method names to error messages. Uses configure to determine
2976 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2977 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002978
2979- distutils: Update to version 0.9.3.
2980
2981- dl: Add several dl.RTLD_ constants.
2982
2983- fpectl: Now supported on FreeBSD.
2984
2985- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2986 found by the collector will be saved in gc.garbage. This is useful
2987 for debugging a program that creates reference cycles.
2988
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002989- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002990 of HTTP class. Do not close socket on zero-length response. Do not
2991 crash when server sends invalid content-length header.
2992
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002993- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002994
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002995- marshal: When reading a short, sign-extend on platforms where shorts
2996 are bigger than 16 bits. When reading a long, repair the unportable
2997 sign extension that was being done for 64-bit machines. (It assumed
2998 that signed right shift sign-extends.)
2999
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003000- operator: Add contains(), invert(), __invert__() as aliases for
3001 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003002
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003003- os: Add support for popen2() and popen3() on all platforms where
3004 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003005
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003006- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003007 clicking on a file in Explorer (or passing the file name to the
3008 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003009
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003010- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003011 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003012
3013- pickle: Now raises ValueError when an invalid pickle that contains
3014 a non-string repr where a string repr was expected. This behavior
3015 matches cPickle.
3016
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003017- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003018
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003019- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003020
3021- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003022 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003023 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024
3025- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003026 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003027
3028- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003029 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003030 few cycles during startup since the first call to
3031 setdefaultencoding() will initialize the codec registry and the
3032 encodings package.
3033
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003034- socket: Support for size hint in readlines() method of object returned
3035 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003036
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003037- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003038 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003039 is followed by whitespace.
3040
Tim Petersa3a3a032000-11-30 05:22:44 +00003041- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003042
3043- struct: Check ranges for bytes and shorts.
3044
3045- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003046 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003047
3048- Tkinter: Image objects are now guaranteed to have unique ids. Set
3049 event.delta to zero if Tk version doesn't support mousewheel.
3050 Removed some debugging prints.
3051
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003052- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003053
Fred Drake67233bc2000-09-26 16:40:27 +00003054- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003055 which works around a bug in Norton AntiVirus 2000 that leads directly
3056 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003057
3058- xml: New version detection code allows PyXML to override standard
3059 XML package if PyXML version is greater than 0.6.1.
3060
Fred Drake64bb3802000-09-26 16:21:35 +00003061- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3062 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3063 tree only for nodes which are sufficiently interesting to a specific
3064 application. Does not provide the HTML-specific extensions. Still
3065 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003066
Fred Drake64bb3802000-09-26 16:21:35 +00003067- xml.sax: SAX 2 support for Python, including all the handler
3068 interfaces needed to process XML 1.0 compliant XML. Some
3069 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003070
Fred Drake64bb3802000-09-26 16:21:35 +00003071- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3072 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003073
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003074
Jeremy Hylton1b618592000-09-26 05:32:36 +00003075C API
3076
3077- Add three new convenience functions for module initialization --
3078 PyModule_AddObject(), PyModule_AddIntConstant(), and
3079 PyModule_AddStringConstant().
3080
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003081- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003082 removed and add #error to Python.h if NULL isn't defined after
3083 #include of stdio.h.
3084
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003085- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003086 backwards compatibility (at the source level) with old extensions.
3087
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003088- A wrapper API was added for signal() and sigaction(). Instead of
3089 either function, always use PyOS_getsig() to get a signal handler
3090 and PyOS_setsig() to set one. A new convenience typedef
3091 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003092
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003093- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003094 internal data buffer and size of a string object -- or the default
3095 encoded version of a Unicode object.
3096
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003097- PyString_Size() and PyString_AsString() accept Unicode objects.
3098
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003099- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003100 exists). INT_MAX and LONG_MAX will always be defined, even if
3101 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003102
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003103- PyFloat_FromString takes a second argument, pend, that was
3104 effectively useless. It is now officially useless but preserved for
3105 backwards compatibility. If the pend argument is not NULL, *pend is
3106 set to NULL.
3107
3108- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3109 for the attribute name. See note on getattr() above.
3110
3111- A few bug fixes to argument processing for Unicode.
3112 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3113 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3114 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003115 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003116
3117- Py_BuildValue accepts B format (for bgen-generated code).
3118
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003119
Jeremy Hylton1b618592000-09-26 05:32:36 +00003120Internals
3121
3122- On Unix, fix code for finding Python installation directory so that
3123 it works when argv[0] is a relative path.
3124
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003125- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003126 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003127 rather than by generating a copy of the object.
3128
Tim Peters482c0212000-09-26 06:33:09 +00003129- Several of the internal Unicode tables are much smaller now, and
3130 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003131
Jeremy Hylton97693b02000-09-26 17:42:51 +00003132- In the garbage collector: Fixed bug in collection of tuples. Fixed
3133 bug that caused some instances to be removed from the container set
3134 while they were still live. Fixed parsing in gc.set_debug() for
3135 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003136
3137- Fixed refcount problem in instance deallocation that only occurred
3138 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3139
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003140- On Windows, getpythonregpath is now protected against null data in
3141 registry key.
3142
3143- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003144 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003145
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003146
Jeremy Hylton1b618592000-09-26 05:32:36 +00003147Build and platform-specific issues
3148
3149- Better support of GNU Pth via --with-pth configure option.
3150
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003151- Python/C API now properly exposed to dynamically-loaded extension
3152 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003153
3154- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3155 Don't define MS_SYNC to be zero when it is undefined. Added missing
3156 prototypes in posixmodule.c.
3157
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003158- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003159 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003160
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003161- Fix largefile support on older NetBSD systems and OpenBSD by adding
3162 define for TELL64.
3163
3164
3165Tools and other miscellany
3166
3167- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3168
3169- freeze: The modulefinder now works with 2.0 opcodes.
3170
Tim Petersa3a3a032000-11-30 05:22:44 +00003171- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003172 Move hackery of sys.argv until after the Tk instance has been
3173 created, which allows the application-specific Tkinter
3174 initialization to be executed if present; also pass an explicit
3175 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003176
Jeremy Hylton1b618592000-09-26 05:32:36 +00003177
3178What's new in 2.0 beta 1?
3179=========================
3180
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003181Source Incompatibilities
3182------------------------
3183
3184None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3185such as single-argument append(), connect() and bind(), and changes to
3186str(long) and repr(float).
3187
3188
3189Binary Incompatibilities
3190------------------------
3191
3192- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3193with Python 2.0; these extensions will have to be rebuilt for Python
31942.0.
3195
3196- On Windows, attempting to import a third party extension built for
3197Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3198can do about this. Check your PYTHONPATH environment variable!
3199
3200- Python bytecode files (*.pyc and *.pyo) are not compatible between
3201releases.
3202
3203
3204Overview of Changes Since 1.6
3205-----------------------------
3206
3207There are many new modules (including brand new XML support through
3208the xml package, and i18n support through the gettext module); a list
3209of all new modules is included below. Lots of bugs have been fixed.
3210
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003211The process for making major new changes to the language has changed
3212since Python 1.6. Enhancements must now be documented by a Python
3213Enhancement Proposal (PEP) before they can be accepted.
3214
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003215There are several important syntax enhancements, described in more
3216detail below:
3217
3218 - Augmented assignment, e.g. x += 1
3219
3220 - List comprehensions, e.g. [x**2 for x in range(10)]
3221
3222 - Extended import statement, e.g. import Module as Name
3223
3224 - Extended print statement, e.g. print >> file, "Hello"
3225
3226Other important changes:
3227
3228 - Optional collection of cyclical garbage
3229
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003230Python Enhancement Proposal (PEP)
3231---------------------------------
3232
3233PEP stands for Python Enhancement Proposal. A PEP is a design
3234document providing information to the Python community, or describing
3235a new feature for Python. The PEP should provide a concise technical
3236specification of the feature and a rationale for the feature.
3237
3238We intend PEPs to be the primary mechanisms for proposing new
3239features, for collecting community input on an issue, and for
3240documenting the design decisions that have gone into Python. The PEP
3241author is responsible for building consensus within the community and
3242documenting dissenting opinions.
3243
3244The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003245
3246Augmented Assignment
3247--------------------
3248
3249This must have been the most-requested feature of the past years!
3250Eleven new assignment operators were added:
3251
Guido van Rossume905e952000-09-05 12:42:46 +00003252 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003253
3254For example,
3255
3256 A += B
3257
3258is similar to
3259
3260 A = A + B
3261
3262except that A is evaluated only once (relevant when A is something
3263like dict[index].attr).
3264
3265However, if A is a mutable object, A may be modified in place. Thus,
3266if A is a number or a string, A += B has the same effect as A = A+B
3267(except A is only evaluated once); but if a is a list, A += B has the
3268same effect as A.extend(B)!
3269
3270Classes and built-in object types can override the new operators in
3271order to implement the in-place behavior; the not-in-place behavior is
3272used automatically as a fallback when an object doesn't implement the
3273in-place behavior. For classes, the method name is derived from the
3274method name for the corresponding not-in-place operator by inserting
3275an 'i' in front of the name, e.g. __iadd__ implements in-place
3276__add__.
3277
3278Augmented assignment was implemented by Thomas Wouters.
3279
3280
3281List Comprehensions
3282-------------------
3283
3284This is a flexible new notation for lists whose elements are computed
3285from another list (or lists). The simplest form is:
3286
3287 [<expression> for <variable> in <sequence>]
3288
Guido van Rossum56db0952000-09-06 23:34:25 +00003289For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003290This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003291
3292You can also add a condition:
3293
3294 [<expression> for <variable> in <sequence> if <condition>]
3295
3296For example, [w for w in words if w == w.lower()] would yield the list
3297of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003298than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003299
3300You can also have nested for loops and more than one 'if' clause. For
3301example, here's a function that flattens a sequence of sequences::
3302
3303 def flatten(seq):
3304 return [x for subseq in seq for x in subseq]
3305
3306 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3307
3308This prints
3309
3310 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3311
3312List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003313Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003314
3315
3316Extended Import Statement
3317-------------------------
3318
3319Many people have asked for a way to import a module under a different
3320name. This can be accomplished like this:
3321
3322 import foo
3323 bar = foo
3324 del foo
3325
3326but this common idiom gets old quickly. A simple extension of the
3327import statement now allows this to be written as follows:
3328
3329 import foo as bar
3330
3331There's also a variant for 'from ... import':
3332
3333 from foo import bar as spam
3334
3335This also works with packages; e.g. you can write this:
3336
3337 import test.regrtest as regrtest
3338
3339Note that 'as' is not a new keyword -- it is recognized only in this
3340context (this is only possible because the syntax for the import
3341statement doesn't involve expressions).
3342
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003343Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003344
3345
3346Extended Print Statement
3347------------------------
3348
3349Easily the most controversial new feature, this extension to the print
3350statement adds an option to make the output go to a different file
3351than the default sys.stdout.
3352
3353For example, to write an error message to sys.stderr, you can now
3354write:
3355
3356 print >> sys.stderr, "Error: bad dog!"
3357
3358As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003359evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003360
3361 print >> None, "Hello world"
3362
3363is equivalent to
3364
3365 print "Hello world"
3366
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003367Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003368
3369
3370Optional Collection of Cyclical Garbage
3371---------------------------------------
3372
3373Python is now equipped with a garbage collector that can hunt down
3374cyclical references between Python objects. It's no replacement for
3375reference counting; in fact, it depends on the reference counts being
3376correct, and decides that a set of objects belong to a cycle if all
3377their reference counts can be accounted for from their references to
3378each other. This devious scheme was first proposed by Eric Tiedemann,
3379and brought to implementation by Neil Schemenauer.
3380
3381There's a module "gc" that lets you control some parameters of the
3382garbage collection. There's also an option to the configure script
3383that lets you enable or disable the garbage collection. In 2.0b1,
3384it's on by default, so that we (hopefully) can collect decent user
3385experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003386performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003387off by default in the final 2.0 release.
3388
3389
3390Smaller Changes
3391---------------
3392
3393A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3394map(None, seq1, seq2, ...) when the sequences have the same length;
3395i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3396the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003397zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003398
3399sys.version_info is a tuple (major, minor, micro, level, serial).
3400
3401Dictionaries have an odd new method, setdefault(key, default).
3402dict.setdefault(key, default) returns dict[key] if it exists; if not,
3403it sets dict[key] to default and returns that value. Thus:
3404
3405 dict.setdefault(key, []).append(item)
3406
3407does the same work as this common idiom:
3408
3409 if not dict.has_key(key):
3410 dict[key] = []
3411 dict[key].append(item)
3412
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003413There are two new variants of SyntaxError that are raised for
3414indentation-related errors: IndentationError and TabError.
3415
3416Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3417escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003418
3419The limits on the size of expressions and file in Python source code
3420have been raised from 2**16 to 2**32. Previous versions of Python
3421were limited because the maximum argument size the Python VM accepted
3422was 2**16. This limited the size of object constructor expressions,
3423e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3424limit was raised thanks to a patch by Charles Waldman that effectively
3425fixes the problem. It is now much more likely that you will be
3426limited by available memory than by an arbitrary limit in Python.
3427
3428The interpreter's maximum recursion depth can be modified by Python
3429programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3430limit is the maximum number of recursive calls that can be made by
3431Python code. The limit exists to prevent infinite recursion from
3432overflowing the C stack and causing a core dump. The default value is
34331000. The maximum safe value for a particular platform can be found
3434by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003435
3436New Modules and Packages
3437------------------------
3438
3439atexit - for registering functions to be called when Python exits.
3440
3441imputil - Greg Stein's alternative API for writing custom import
3442hooks.
3443
3444pyexpat - an interface to the Expat XML parser, contributed by Paul
3445Prescod.
3446
3447xml - a new package with XML support code organized (so far) in three
3448subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3449would fill a volume. There's a special feature whereby a
3450user-installed package named _xmlplus overrides the standard
3451xmlpackage; this is intended to give the XML SIG a hook to distribute
3452backwards-compatible updates to the standard xml package.
3453
3454webbrowser - a platform-independent API to launch a web browser.
3455
3456
Guido van Rossume905e952000-09-05 12:42:46 +00003457Changed Modules
3458---------------
3459
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003460array -- new methods for array objects: count, extend, index, pop, and
3461remove
3462
3463binascii -- new functions b2a_hex and a2b_hex that convert between
3464binary data and its hex representation
3465
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003466calendar -- Many new functions that support features including control
3467over which day of the week is the first day, returning strings instead
3468of printing them. Also new symbolic constants for days of week,
3469e.g. MONDAY, ..., SUNDAY.
3470
3471cgi -- FieldStorage objects have a getvalue method that works like a
3472dictionary's get method and returns the value attribute of the object.
3473
3474ConfigParser -- The parser object has new methods has_option,
3475remove_section, remove_option, set, and write. They allow the module
3476to be used for writing config files as well as reading them.
3477
3478ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003479optionally support the RFC 959 REST command.
3480
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003481gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003482
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003483httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3484the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003485
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003486locale -- implement getdefaultlocale for Win32 and Macintosh
3487
3488marshal -- no longer dumps core when marshaling deeply nested or
3489recursive data structures
3490
3491os -- new functions isatty, seteuid, setegid, setreuid, setregid
3492
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003493os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3494support under Unix.
3495
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003496os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003497
3498os.path -- fix semantics of os.path.commonprefix
3499
3500smtplib -- support for sending very long messages
3501
3502socket -- new function getfqdn()
3503
3504readline -- new functions to read, write and truncate history files.
3505The readline section of the library reference manual contains an
3506example.
3507
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003508select -- add interface to poll system call
3509
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003510shutil -- new copyfileobj function
3511
3512SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3513HTTP server.
3514
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003515Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003516
3517urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003518e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003519
3520whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003521
3522
3523Obsolete Modules
3524----------------
3525
3526None. However note that 1.6 made a whole slew of modules obsolete:
3527stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3528poly, zmod, strop, util, whatsound.
3529
3530
3531Changed, New, Obsolete Tools
3532----------------------------
3533
Tim Peters8b092332000-09-05 20:15:25 +00003534None.
Guido van Rossume905e952000-09-05 12:42:46 +00003535
3536
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003537C-level Changes
3538---------------
3539
3540Several cleanup jobs were carried out throughout the source code.
3541
3542All C code was converted to ANSI C; we got rid of all uses of the
3543Py_PROTO() macro, which makes the header files a lot more readable.
3544
3545Most of the portability hacks were moved to a new header file,
3546pyport.h; several other new header files were added and some old
3547header files were removed, in an attempt to create a more rational set
3548of header files. (Few of these ever need to be included explicitly;
3549they are all included by Python.h.)
3550
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003551Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003552and Win64, especially for the new Intel Itanium processor. Mick also
3553added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003554
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003555The C APIs to return an object's size have been update to consistently
3556use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3557previous versions, the abstract interfaces used PyXXX_Length and the
3558concrete interfaces used PyXXX_Size. The old names,
3559e.g. PyObject_Length, are still available for backwards compatibility
3560at the API level, but are deprecated.
3561
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003562The PyOS_CheckStack function has been implemented on Windows by
3563Fredrik Lundh. It prevents Python from failing with a stack overflow
3564on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003565
3566The GC changes resulted in creation of two new slots on object,
3567tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003568the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003569
3570The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003571C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003572
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003573PyErr_Format has been updated to automatically calculate the size of
3574the buffer needed to hold the formatted result string. This change
3575prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003576
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003577New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003578
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003579PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3580that are the same as their non-Ex counterparts except they take an
3581extra flag argument that tells them to close the file when done.
3582
3583XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003584
Tim Peters8b092332000-09-05 20:15:25 +00003585
3586Windows Changes
3587---------------
3588
3589New popen2/popen3/peopen4 in os module (see Changed Modules above).
3590
3591os.popen is much more usable on Windows 95 and 98. See Microsoft
3592Knowledge Base article Q150956. The Win9x workaround described there
3593is implemented by the new w9xpopen.exe helper in the root of your
3594Python installation. Note that Python uses this internally; it is not
3595a standalone program.
3596
3597Administrator privileges are no longer required to install Python
3598on Windows NT or Windows 2000. If you have administrator privileges,
3599Python's registry info will be written under HKEY_LOCAL_MACHINE.
3600Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003601under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003602uses of Python, but will prevent some advanced uses from working
3603(for example, running a Python script as an NT service, or possibly
3604from CGI).
3605
3606[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3607installer; instead, it installs the needed Tcl/Tk files directly in the
3608Python directory. If you already have a Tcl/Tk installation, this
3609wastes some disk space (about 4 Megs) but avoids problems with
3610conflicting Tcl/Tk installations, and makes it much easier for Python
3611to ensure that Tcl/Tk can find all its files.
3612
3613[This was new in 1.6] The Windows installer now installs by default in
3614\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3615
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003616
3617Updates to the changes between 1.5.2 and 1.6
3618--------------------------------------------
3619
3620The 1.6 NEWS file can't be changed after the release is done, so here
3621is some late-breaking news:
3622
3623New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3624and changes to getlocale() and setlocale().
3625
3626The new module is now enabled per default.
3627
3628It is not true that the encodings codecs cannot be used for normal
3629strings: the string.encode() (which is also present on 8-bit strings
3630!) allows using them for 8-bit strings too, e.g. to convert files from
3631cp1252 (Windows) to latin-1 or vice-versa.
3632
3633Japanese codecs are available from Tamito KAJIYAMA:
3634http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3635
3636
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003637======================================================================