blob: 4a4119768ee557cebad0dd4aea56c076cbad63f2 [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
Fred Draked0ba6362002-05-02 21:28:26 +00009- Deprecated features of xrange objects have been removed as
10 promised. The start, stop, and step attributes and the tolist()
11 method no longer exist. xrange repetition and slicing have been
12 removed.
13
Guido van Rossum7dab2422002-04-26 19:40:56 +000014- New builtin function enumerate(x), from PEP 279. Example:
15 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
16 The argument can be an arbitrary iterable object.
17
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000018- The assert statement no longer tests __debug__ at runtime. This means
19 that assert statements cannot be disabled by assigning a false value
20 to __debug__.
21
Walter Dörwald068325e2002-04-15 13:36:47 +000022- A method zfill() was added to str and unicode, that fills a numeric
23 string to the left with zeros. For example,
24 "+123".zfill(6) -> "+00123".
25
Guido van Rossum862fe3c2002-04-15 12:36:47 +000026- Complex numbers supported divmod() and the // and % operators, but
27 these make no sense. Since this was documented, they're being
28 deprecated now.
29
Guido van Rossum26dd8302002-04-26 20:11:29 +000030- String and unicode methods lstrip(), rstrip() and strip() now take
31 an optional argument that specifies the characters to strip. For
32 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000033
Guido van Rossumc69343b2002-04-12 19:22:48 +000034- Added a new dict method pop(key). This removes and returns the
35 value corresponding to key. [SF patch #539949]
36
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000037- Changed new-style class instantiation so that when C's __new__
38 method returns something that's not a C instance, its __init__ is
39 not called. [SF bug #537450]
40
Guido van Rossum181e41a2002-04-06 00:23:25 +000041- Fixed super() to work correctly with class methods. [SF bug #535444]
42
Guido van Rossum47834462002-04-04 15:21:33 +000043- A new built-in type, bool, has been added, as well as built-in
44 names for its two values, True and False. Comparisons and sundry
45 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000046 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000047 is backward compatible.
48
Guido van Rossum95b62a62002-03-29 01:07:24 +000049- Fixed two bugs reported as SF #535905: under certain conditions,
50 deallocating a deeply nested structure could cause a segfault in the
51 garbage collector, due to interaction with the "trashcan" code;
52 access to the current frame during destruction of a local variable
53 could access a pointer to freed memory.
54
Neil Schemenauer9d50d132002-03-22 17:06:59 +000055- The optional object allocator has been enabled by default.
56
Guido van Rossum8c842552002-03-14 23:05:54 +000057- If you try to pickle an instance of a class that has __slots__ but
58 doesn't define or override __getstate__, a TypeError is now raised.
59 This is done by adding a bozo __getstate__ to the class that always
60 raises TypeError. (Before, this would appear to be pickled, but the
61 state of the slots would be lost.)
62
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000063- PyErr_Display will provide file and line information for all exceptions
64 that have an attribute print_file_and_line, not just SyntaxErrors.
65
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000066- The UTF-8 codec will now encode and decode Unicode surrogates
67 correctly and without raising exceptions for unpaired ones.
68
Neal Norwitz649b7592002-01-01 19:07:13 +000069- file.xreadlines() now raises a ValueError if the file is closed:
70 Previously, an xreadlines object was returned which would raise
71 a ValueError when the xreadlines.next() method was called.
72
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000073- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +000074 An exception will now be raised if more than one argument is used.
75
Tim Petersaf8446f2001-12-21 21:36:50 +000076Extension modules
77
Tim Peters81b92512002-04-29 01:37:32 +000078- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +000079 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +000080 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +000081
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000082- posix.killpg and posix.mknod have been added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +000083
Martin v. Löwis2e64c342002-03-27 18:49:02 +000084- The locale module now exposes the C library's gettext interface.
85
Tim Petersfbf74f22002-03-14 19:06:01 +000086- A security hole ("double free") was found in zlib-1.1.3, a popular
87 third party compression library used by some Python modules. The
88 hole was quickly plugged in zlib-1.1.4, and the Windows build of
89 Python now ships with zlib-1.1.4.
90
Martin v. Löwis688357e2002-04-08 21:28:20 +000091- pwd, grp, and resource return enhanced tuples now, with symbolic
92 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +000093
Martin v. Löwis99866332002-03-01 10:27:01 +000094- array.array is now a type object. A new format character
95 'u' indicates Py_UNICODE arrays. For those, .tounicode and
96 .fromunicode methods are available. Arrays now support __iadd__
97 and __imul__.
98
Neal Norwitze790eae2002-01-01 21:14:12 +000099- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000100 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
101 is called.
102
Tim Petersaf8446f2001-12-21 21:36:50 +0000103Library
104
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000105- added degree/radian conversion functions to the math module.
106
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000107- ftplib.retrlines() now tests for callback is None rather than testing
108 for False. Was causing an error when given a callback object which
109 was callable but also returned len() as zero. The change may
110 create new breakage if the caller relied on the undocumented behavior
111 and called with callback set to [] or some other False value not
112 identical to None.
113
Tim Peters46c04e12002-05-05 20:40:00 +0000114- random.gauss() uses a piece of hidden state used by nothing else,
115 and the .seed() and .whseed() methods failed to reset it. In other
116 words, setting the seed didn't completely determine the sequence of
117 results produced by random.gauss(). It does now. Programs repeatedly
118 mixing calls to a seed method with calls to gauss() may see different
119 results now.
120
Fred Drake7f781c92002-05-01 20:33:53 +0000121- The pickle.Pickler class grew a clear_memo() method to mimic that
122 provided by cPickle.Pickler.
123
Tim Peters81b92512002-04-29 01:37:32 +0000124- difflib's SequenceMatcher class now does a dynamic analysis of
125 which elements are so frequent as to constitute noise. For
126 comparing files as sequences of lines, this generally works better
127 than the IS_LINE_JUNK function, and function ndiff's linejunk
128 argument defaults to None now as a result. A happy benefit is
129 that SequenceMatcher may run much faster now when applied
130 to large files with many duplicate lines (for example, C program
131 text with lots of repeated "}" and "return NULL;" lines).
132
Guido van Rossum256705b2002-04-23 13:29:43 +0000133- New Text.dump() method in Tkinter module.
134
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000135- New distutils commands for building packagers were added to
136 support pkgtool on Solaris and swinstall on HP-UX.
137
138- distutils now has a new abstract binary packager base class
139 command/bdist_packager, which simplifies writing packagers.
140 This will hopefully provide the missing bits to encourage
141 people to submit more packagers, e.g. for Debian, FreeBSD
142 and other systems.
143
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000144- The UTF-16, -LE and -BE now raise a NotImplementedError
145 for all calls to .readline(). Previously, they used to just
146 produce garbage or fail with an encoding error -- UTF-16 is
147 a 2-byte encoding and the C lib's line reading APIs don't
148 work well with these.
149
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000150- compileall now supports quiet operation.
151
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000152- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000153 connections.
154
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000155- socket module: the SSL support was broken out of the main
156 _socket module C helper and placed into a new _ssl helper
157 which now gets imported by socket.py if available and working.
158
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000159- encodings package: added aliases for all supported IANA character
160 sets
161
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000162- ftplib: to safeguard the user's privacy, anonymous login will use
163 "anonymous@" as default password, rather than the real user and host
164 name.
165
Fred Drake36736122002-01-10 13:50:31 +0000166- webbrowser: tightened up the command passed to os.system() so that
167 arbitrary shell code can't be executed because a bogus URL was
168 passed in.
169
Tim Peters11bd9942002-02-01 00:52:29 +0000170- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000171 gettext.find an optional all argument. Translations will now fallback
172 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000173
Martin v. Löwis9668b932002-01-12 11:27:42 +0000174- distutils bdist commands now offer a --skip-build option.
175
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000176- warnings.warn now accepts a Warning instance as first argument.
177
Fred Drakefed7e852002-04-04 19:36:15 +0000178- The xml.sax.expatreader.ExpatParser class will no longer create
179 circular references by using itself as the locator that gets passed
180 to the content handler implementation. [SF bug #535474]
181
Tim Petersaf8446f2001-12-21 21:36:50 +0000182Tools/Demos
183
Marc-André Lemburg46260092002-04-04 16:17:11 +0000184- freeze.py now produces binaries which can import shared modules,
185 unlike before when this failed due to missing symbol exports in
186 the generated binary.
187
Tim Petersaf8446f2001-12-21 21:36:50 +0000188Build
189
Tim Peters639295f2002-04-21 07:30:30 +0000190- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
191 say how or when to configure it, or how to turn it off.
192
Martin v. Löwis1142de32002-03-29 16:28:31 +0000193- On Unix, a shared libpython2.3.so can be created with --enable-shared.
194
Tim Peters8deda702002-03-30 10:06:07 +0000195- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
196 preprocessor symbols were eliminated. The internal decisions they
197 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000198
Fred Drake7d28b732002-05-02 21:17:00 +0000199- The tools used to build the documentation now work under Cygwin as
200 well as Unix.
201
Tim Petersaf8446f2001-12-21 21:36:50 +0000202C API
203
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000204- Added new macro PySequence_ITEM(o, i) that directly calls
205 sq_item without rechecking that o is a sequence and without
206 adjusting for negative indices.
207
Fred Draked0ba6362002-05-02 21:28:26 +0000208- PyRange_New() now raises ValueError if the fourth argument is not 1.
209 This is part of the removal of deprecated features of the xrange
210 object.
211
Guido van Rossum517c7d42002-04-26 02:49:14 +0000212- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
213 coercion if both arguments have the same type but this type has the
214 CHECKTYPES flag set. This is to better support proxies.
215
Neil Schemenauer9344b142002-04-12 23:00:08 +0000216- The type of tp_free has been changed from "void (*)(PyObject *)" to
217 "void (*)(void *)".
218
219- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
220
Guido van Rossum0986d822002-04-08 01:38:42 +0000221- A type can now inherit its metatype from its base type. Previously,
222 when PyType_Ready() was called, if ob_type was found to be NULL, it
223 was always set to &PyType_Type; now it is set to base->ob_type,
224 where base is tp_base, defaulting to &PyObject_Type.
225
226- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
227
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000228- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000229
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000230- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000231 without going through the buffer API.
232
Martin v. Löwis7198a522002-01-01 19:59:11 +0000233- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
234
Tim Peters10a3bb52001-12-25 19:07:38 +0000235- An old #define of ANY as void has been removed from pyport.h. This
236 hasn't been used since Python's pre-ANSI days, and the #define has
237 been marked as obsolete since then. SF bug 495548 says it created
238 conflicts with other packages, so keeping it around wasn't harmless.
239
Tim Petersaf8446f2001-12-21 21:36:50 +0000240- Because Python's magic number scheme broke on January 1st, we decided
241 to stop Python development. Thanks for all the fish!
242
Tim Petersfb05db22002-03-11 00:24:00 +0000243- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000244 scheme to a new one. See Python/import.c for details.
245
Tim Petersaf8446f2001-12-21 21:36:50 +0000246New platforms
247
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000248- GNU/Hurd is now supported.
249
Tim Petersaf8446f2001-12-21 21:36:50 +0000250Tests
251
252Windows
253
Tim Peters08e72952002-04-16 20:48:01 +0000254- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
255 of that has been fixed in the installer (disabled Wise's "delete in-
256 use files" uninstall option).
257
Guido van Rossum181e41a2002-04-06 00:23:25 +0000258- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
259
Tim Peters33187922002-04-04 20:02:04 +0000260- The installer now installs Start menu shortcuts under (the local
261 equivalent of) "All Users" when doing an Admin install.
262
Tim Petersfb05db22002-03-11 00:24:00 +0000263- file.truncate([newsize]) now works on Windows for all newsize values.
264 It used to fail if newsize didn't fit in 32 bits, reflecting a
265 limitation of MS _chsize (which is no longer used).
266
Tim Petersab034fa2002-02-01 11:27:43 +0000267- os.waitpid() is now implemented for Windows, and can be used to block
268 until a specified process exits. This is similar to, but not exactly
269 the same as, os.waitpid() on POSIX systems. If you're waiting for
270 a specific process whose pid was obtained from one of the spawn()
271 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000272 See the docs for details. The docs were changed to clarify that
273 spawn functions return, and waitpid requires, a process handle on
274 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000275
Tim Peters11bd9942002-02-01 00:52:29 +0000276- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000277 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000278 to a nasty problem: before 2.3, if you got a temp file on Windows, it
279 got wrapped in an object whose close() method first closed the
280 underlying file, then deleted the file. This usually worked fine.
281 However, the spawn family of functions on Windows create (at a low C
282 level) the same set of open files in the spawned process Q as were
283 open in the spawning process P. If a temp file f was among them, then
284 doing f.close() in P first closed P's C-level file handle on f, but Q's
285 C-level file handle on f remained open, so the attempt in P to delete f
286 blew up with a "Permission denied" error (Windows doesn't allow
287 deleting open files). This was surprising, subtle, and difficult to
288 work around.
289
290- The os module now exports all the symbolic constants usable with the
291 low-level os.open() on Windows: the new constants in 2.3 are
292 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
293 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
294 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
295 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
296 (so specify both if you want both; note that neither is useful unless
297 specified with O_CREAT too).
298
Tim Petersaf8446f2001-12-21 21:36:50 +0000299Mac
300
301
Tim Peters909c0912001-12-14 23:16:18 +0000302What's New in Python 2.2 final?
303Release date: 21-Dec-2001
304===============================
305
306Type/class unification and new-style classes
307
Barry Warsaw52acb492001-12-21 20:04:22 +0000308- pickle.py, cPickle: allow pickling instances of new-style classes
309 with a custom metaclass.
310
Tim Peters909c0912001-12-14 23:16:18 +0000311Core and builtins
312
Barry Warsaw52acb492001-12-21 20:04:22 +0000313- weakref proxy object: when comparing, unwrap both arguments if both
314 are proxies.
315
Tim Peters909c0912001-12-14 23:16:18 +0000316Extension modules
317
Barry Warsaw52acb492001-12-21 20:04:22 +0000318- binascii.b2a_base64(): fix a potential buffer overrun when encoding
319 very short strings.
320
321- cPickle: the obscure "fast" mode was suspected of causing stack
322 overflows on the Mac. Hopefully fixed this by setting the recursion
323 limit much smaller. If the limit is too low (it only affects
324 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
325 when compiling cPickle.c (or in pyconfig.h).
326
Tim Peters909c0912001-12-14 23:16:18 +0000327Library
328
Barry Warsaw52acb492001-12-21 20:04:22 +0000329- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
330 close or delete time).
331
332- rfc822.py: fixed a bug where the address '<>' was converted to None
333 instead of an empty string (also fixes the email.Utils module).
334
335- xmlrpclib.py: version 1.0.0; uses precision for doubles.
336
337- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000338 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000339
Tim Peters909c0912001-12-14 23:16:18 +0000340Tools/Demos
341
342Build
343
344C API
345
346New platforms
347
348Tests
349
350Windows
351
Barry Warsaw52acb492001-12-21 20:04:22 +0000352- distutils package: fixed broken Windows installers (bdist_wininst).
353
354- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
355 instances are deleted at process exit time.
356
357- socket.py: prevent mysterious warnings when socket instances are
358 deleted at process exit time.
359
360- posixmodule.c: fix a Windows crash with stat() of a filename ending
361 in backslash.
362
Tim Peters909c0912001-12-14 23:16:18 +0000363Mac
364
Barry Warsaw52acb492001-12-21 20:04:22 +0000365- The Carbon toolbox modules have been upgraded to Universal Headers
366 3.4, and experimental CoreGraphics and CarbonEvents modules have
367 been added. All only for framework-enabled MacOSX.
368
Tim Peters909c0912001-12-14 23:16:18 +0000369
Tim Peters6272dfd2001-12-13 19:34:00 +0000370What's New in Python 2.2c1?
371Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000372===========================
373
374Type/class unification and new-style classes
375
Barry Warsaw06557452001-12-14 20:47:12 +0000376- Guido's tutorial introduction to the new type/class features has
377 been extensively updated. See
378
379 http://www.python.org/2.2/descrintro.html
380
381 That remains the primary documentation in this area.
382
Guido van Rossum33bab012001-12-05 22:45:48 +0000383- Fixed a leak: instance variables declared with __slots__ were never
384 deleted!
385
Guido van Rossum4b800852001-12-03 00:54:52 +0000386- The "delete attribute" method of descriptor objects is called
387 __delete__, not __del__. In previous releases, it was mistakenly
388 called __del__, which created an unfortunate overloading condition
389 with finalizers. (The "get attribute" and "set attribute" methods
390 are still called __get__ and __set__, respectively.)
391
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000392- Some subtle issues with the super built-in were fixed:
393
394 (a) When super itself is subclassed, its __get__ method would still
395 return an instance of the base class (i.e., of super).
396
397 (b) super(C, C()).__class__ would return C rather than super. This
398 is confusing. To fix this, I decided to change the semantics of
399 super so that it only applies to code attributes, not to data
400 attributes. After all, overriding data attributes is not
401 supported anyway.
402
403 (c) The __get__ method didn't check whether the argument was an
404 instance of the type used in creation of the super instance.
405
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000406- Previously, hash() of an instance of a subclass of a mutable type
407 (list or dictionary) would return some value, rather than raising
408 TypeError. This has been fixed. Also, directly calling
409 dict.__hash__ and list.__hash__ now raises the same TypeError
410 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000411
Guido van Rossumd331cb52001-12-05 19:46:42 +0000412- New-style objects now support deleting their __dict__. This is for
413 all intents and purposes equivalent to assigning a brand new empty
414 dictionary, but saves space if the object is not used further.
415
Tim Petersb3c9af12001-11-17 00:21:57 +0000416Core and builtins
417
Tim Peters3caca232001-12-06 06:23:26 +0000418- -Qnew now works as documented in PEP 238: when -Qnew is passed on
419 the command line, all occurrences of "/" use true division instead
420 of classic division. See the PEP for details. Note that "all"
421 means all instances in library and 3rd-party modules, as well as in
422 your own code. As the PEP says, -Qnew is intended for use only in
423 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000424 Note that test_coercion.py in the standard Python test suite fails
425 under -Qnew; this is expected, and won't be repaired until true
426 division becomes the default (in the meantime, test_coercion is
427 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000428
Fred Drake6c01e252001-12-14 17:08:12 +0000429- complex() now only allows the first argument to be a string
430 argument, and raises TypeError if either the second arg is a string
431 or if the second arg is specified when the first is a string.
432
Tim Petersb3c9af12001-11-17 00:21:57 +0000433Extension modules
434
Martin v. Löwis560da622001-11-24 09:24:51 +0000435- gc.get_referents was renamed to gc.get_referrers.
436
Tim Petersb3c9af12001-11-17 00:21:57 +0000437Library
438
Tim Peters25059d32001-12-07 20:35:43 +0000439- Functions in the os.spawn() family now release the global interpreter
440 lock around calling the platform spawn. They should always have done
441 this, but did not before 2.2c1. Multithreaded programs calling
442 an os.spawn function with P_WAIT will no longer block all Python threads
443 until the spawned program completes. It's possible that some programs
444 relies on blocking, although more likely by accident than by design.
445
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000446- webbrowser defaults to netscape.exe on OS/2 now.
447
Martin v. Löwis652e1912001-11-25 14:50:56 +0000448- Tix.ResizeHandle exposes detach_widget, hide, and show.
449
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000450- The charset alias windows_1252 has been added.
451
Barry Warsaw06557452001-12-14 20:47:12 +0000452- types.StringTypes is a tuple containing the defined string types;
453 usually this will be (str, unicode), but if Python was compiled
454 without Unicode support it will be just (str,).
455
456- The pulldom and minidom modules were synchronized to PyXML.
457
Tim Petersb3c9af12001-11-17 00:21:57 +0000458Tools/Demos
459
Barry Warsaw06557452001-12-14 20:47:12 +0000460- A new script called Tools/scripts/google.py was added, which fires
461 off a search on Google.
462
Tim Petersb3c9af12001-11-17 00:21:57 +0000463Build
464
Barry Warsaw06557452001-12-14 20:47:12 +0000465- Note that release builds of Python should arrange to define the
466 preprocessor symbol NDEBUG on the command line (or equivalent).
467 In the 2.2 pre-release series we tried to define this by magic in
468 Python.h instead, but it proved to cause problems for extension
469 authors. The Unix, Windows and Mac builds now all define NDEBUG in
470 release builds via cmdline (or equivalent) instead. Ports to
471 other platforms should do likewise.
472
Jack Jansen1999ef42001-12-06 21:47:20 +0000473- It is no longer necessary to use --with-suffix when building on a
474 case-insensitive file system (such as Mac OS X HFS+). In the build
475 directory an extension is used, but not in the installed python.
476
Tim Petersb3c9af12001-11-17 00:21:57 +0000477C API
478
Tim Petersf582b822001-12-11 18:51:08 +0000479- New function PyDict_MergeFromSeq2() exposes the builtin dict
480 constructor's logic for updating a dictionary from an iterable object
481 producing key-value pairs.
482
Tim Peterscffed4b2001-11-29 03:26:37 +0000483- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000484 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000485 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
486 dump core in some bad cases. This has been repaired. As a result,
487 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
488 previously went unchallenged.
489
Tim Petersb3c9af12001-11-17 00:21:57 +0000490New platforms
491
492Tests
493
494Windows
495
496Mac
497
Jack Jansenffa260f2001-12-06 21:14:00 +0000498- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
499 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000500
Barry Warsaw06557452001-12-14 20:47:12 +0000501- Changed logic for finding python home in Mac OS X framework Pythons.
502 Now sys.executable points to the executable again, in stead of to
503 the shared library. The latter is used only for locating the python
504 home.
505
506
Tim Peters84362bc2001-10-19 17:55:30 +0000507What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000508Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000509===========================
510
511Type/class unification and new-style classes
512
Guido van Rossum3d27df02001-11-15 20:27:54 +0000513- Multiple inheritance mixing new-style and classic classes in the
514 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000515
516 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000517 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000518
519 The MRO (method resolution order) for each base class is respected
520 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000521 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000522 This needs to be documented.
523
Tim Petersa427a2b2001-10-29 22:25:45 +0000524- The new builtin dictionary() constructor, and dictionary type, have
525 been renamed to dict. This reflects a decade of common usage.
526
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000527- dict() now accepts an iterable object producing 2-sequences. For
528 example, dict(d.items()) == d for any dictionary d. The argument,
529 and the elements of the argument, can be any iterable objects.
530
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000531- New-style classes can now have a __del__ method, which is called
532 when the instance is deleted (just like for classic classes).
533
Guido van Rossum12d955c2001-10-26 14:56:06 +0000534- Assignment to object.__dict__ is now possible, for objects that are
535 instances of new-style classes that have a __dict__ (unless the base
536 class forbids it).
537
Guido van Rossumc8e56452001-10-22 00:43:43 +0000538- Methods of built-in types now properly check for keyword arguments
539 (formerly these were silently ignored). The only built-in methods
540 that take keyword arguments are __call__, __init__ and __new__.
541
Guido van Rossum86443212001-10-27 22:28:54 +0000542- The socket function has been converted to a type; see below.
543
Tim Peters84362bc2001-10-19 17:55:30 +0000544Core and builtins
545
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000546- Assignment to __debug__ raises SyntaxError at compile-time. This
547 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000548 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000549
Guido van Rossum12d955c2001-10-26 14:56:06 +0000550- Clarified the error messages for unsupported operands to an operator
551 (like 1 + '').
552
Tim Peters84362bc2001-10-19 17:55:30 +0000553Extension modules
554
Tim Peters5ebfd362001-11-13 23:11:19 +0000555- mmap has a new keyword argument, "access", allowing a uniform way for
556 both Windows and Unix users to create read-only, write-through and
557 copy-on-write memory mappings. This was previously possible only on
558 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000559 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000560 platforms. Thanks to Jay T Miller for repairing this!
561
Tim Peters169ded02001-11-03 19:57:21 +0000562- By default, the gc.garbage list now contains only those instances in
563 unreachable cycles that have __del__ methods; in 2.1 it contained all
564 instances in unreachable cycles. "Instances" here has been generalized
565 to include instances of both new-style and old-style classes.
566
Guido van Rossum12d955c2001-10-26 14:56:06 +0000567- The socket module defines a new method for socket objects,
568 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000569 send() until all data has been sent. Also, the socket function has
570 been converted to a subclassable type, like list and tuple (etc.)
571 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000572
573- Various bugfixes to the curses module. There is now a test suite
574 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000575
Guido van Rossum692adf12001-10-30 03:03:03 +0000576- binascii.b2a_base64 no longer places an arbitrary restriction of 57
577 bytes on its input.
578
Tim Peters84362bc2001-10-19 17:55:30 +0000579Library
580
Tim Peters5ebfd362001-11-13 23:11:19 +0000581- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000582 convenience function.
583
Tim Peters75335872001-11-03 19:35:43 +0000584- Symbolic group names in regular expressions must be unique. For
585 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
586 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000587 Python 2.2 detects this error at regexp compilation time;
588 previously, the error went undetected, and results were
589 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
590 pattern.subn() methods have been rewritten in C. Also, an
591 experimental function/method finditer() has been added, which works
592 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000593
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000594- Tix exposes more commands through the classes DirSelectBox,
595 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
596 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
597 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
598
Tim Peters98791af2001-10-23 01:59:54 +0000599- Traceback objects are now scanned by cyclic garbage collection, so
600 cycles created by casual use of sys.exc_info() no longer cause
601 permanent memory leaks (provided garbage collection is enabled).
602
Guido van Rossum49192142001-10-24 20:51:44 +0000603- os.extsep -- a new variable needed by the RISCOS support. It is the
604 separator used by extensions, and is '.' on all platforms except
605 RISCOS, where it is '/'. There is no need to use this variable
606 unless you have a masochistic desire to port your code to RISCOS.
607
Barry Warsaw012852b2001-11-16 16:17:27 +0000608- mimetypes.py has optional support for non-standard, but commonly
609 found types. guess_type() and guess_extension() now accept an
610 optional `strict' flag, defaulting to true, which controls whether
611 recognize non-standard types or not. A few non-standard types we
612 know about have been added. Also, when run as a script, there are
613 new -l and -e options.
614
615- statcache is now deprecated.
616
617- email.Utils.formatdate() now produces the preferred RFC 2822 style
618 dates with numeric timezones (it used to produce obsolete dates
619 hard coded to "GMT" timezone). An optional `localtime' flag is
620 added to produce dates in the local timezone, with daylight savings
621 time properly taken into account.
622
623- In pickle and cPickle, instead of masking errors in load() by
624 transforming them into SystemError, we let the original exception
625 propagate out. Also, implement support for __safe_for_unpickling__
626 in pickle, as it already was supported in cPickle.
627
Tim Peters84362bc2001-10-19 17:55:30 +0000628Tools/Demos
629
630Build
631
Barry Warsaw012852b2001-11-16 16:17:27 +0000632- The dbm module is built using libdb1 if available. The bsddb module
633 is built with libdb3 if available.
634
635- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
636
Tim Peters84362bc2001-10-19 17:55:30 +0000637C API
638
Tim Peters1fc240e2001-10-26 05:06:50 +0000639- New function PySequence_Fast_GET_SIZE() returns the size of a non-
640 NULL result from PySequence_Fast(), more quickly than calling
641 PySequence_Size().
642
Barry Warsaw012852b2001-11-16 16:17:27 +0000643- New argument unpacking function PyArg_UnpackTuple() added.
644
645- New functions PyObject_CallFunctionObjArgs() and
646 PyObject_CallMethodObjArgs() have been added to make it more
647 convenient and efficient to call functions and methods from C.
648
649- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
650 possible that this will propagate errors it didn't before.
651
652- New function PyObject_CheckReadBuffer(), which returns true if its
653 argument supports the single-segment readable buffer interface.
654
Tim Peters84362bc2001-10-19 17:55:30 +0000655New platforms
656
Guido van Rossum86443212001-10-27 22:28:54 +0000657- We've finally confirmed that this release builds on HP-UX 11.00,
658 *with* threads, and passes the test suite.
659
Tim Peters7a33d8b2001-11-05 02:51:07 +0000660- Thanks to a series of patches from Michael Muller, Python may build
661 again under OS/2 Visual Age C++.
662
Guido van Rossum49192142001-10-24 20:51:44 +0000663- Updated RISCOS port by Dietmar Schwertberger.
664
Tim Peters84362bc2001-10-19 17:55:30 +0000665Tests
666
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000667- Added a test script for the curses module. It isn't run automatically;
668 regrtest.py must be run with '-u curses' to enable it.
669
Tim Peters84362bc2001-10-19 17:55:30 +0000670Windows
671
Barry Warsaw012852b2001-11-16 16:17:27 +0000672Mac
673
674- PythonScript has been moved to unsupported and is slated to be
675 removed completely in the next release.
676
677- It should now be possible to build applets that work on both OS9 and
678 OSX.
679
680- The core is now linked with CoreServices not Carbon; as a side
681 result, default 8bit encoding on OSX is now ASCII.
682
683- Python should now build on OSX 10.1.1
684
Tim Peters84362bc2001-10-19 17:55:30 +0000685
Tim Petersabf925f2001-09-28 21:53:42 +0000686What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000687Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000688===========================
689
690Type/class unification and new-style classes
691
Guido van Rossum687ae002001-10-15 22:03:32 +0000692- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000693 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000694 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000695 remains: the __dict__ of a new-style class is a read-only proxy; you
696 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000697 __defined__ attribute of new-style types no longer exists, for lack
698 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000699 future a __cache__ may be resurrected with a similar function, if I
700 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000701
Tim Peters1c9ca872001-10-04 06:43:12 +0000702- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
703 always returned None, even when there was a class docstring).
704
705- doctest now finds and runs docstrings attached to new-style classes,
706 class methods, static methods, and properties.
707
Guido van Rossum9074ef62001-10-16 21:34:49 +0000708Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000709
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000710- A very subtle syntactical pitfall in list comprehensions was fixed.
711 For example: [a+b for a in 'abc', for b in 'def']. The comma in
712 this example is a mistake. Previously, this would silently let 'a'
713 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
714 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
715 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
716 Note that [a for a in <singleton>] is a convoluted way to say
717 [<singleton>] anyway, so it's not like any expressiveness is lost.
718
Guido van Rossum9074ef62001-10-16 21:34:49 +0000719- getattr(obj, name, default) now only catches AttributeError, as
720 documented, rather than returning the default value for all
721 exceptions (which could mask bugs in a __getattr__ hook, for
722 example).
723
Fred Drakecb7a6b52001-10-22 18:41:51 +0000724- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000725 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000726 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000727 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000728
Guido van Rossum1c486092001-10-19 02:05:35 +0000729- unicode(obj) now behaves more like str(obj), accepting arbitrary
730 objects, and calling a __unicode__ method if it exists.
731 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000732 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000733
Barry Warsawf6fb1712001-10-19 05:35:40 +0000734- isinstance() now allows any object as the first argument and a
735 class, a type or something with a __bases__ tuple attribute for the
736 second argument. The second argument may also be a tuple of a
737 class, type, or something with __bases__, in which case isinstance()
738 will return true if the first argument is an instance of any of the
739 things contained in the second argument tuple. E.g.
740
741 isinstance(x, (A, B))
742
743 returns true if x is an instance of A or B.
744
Guido van Rossum9074ef62001-10-16 21:34:49 +0000745Extension modules
746
747- thread.start_new_thread() now returns the thread ID (previously None).
748
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000749- binascii has now two quopri support functions, a2b_qp and b2a_qp.
750
Guido van Rossumc524d952001-10-19 01:31:59 +0000751- readline now supports setting the startup_hook and the
752 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000753
Guido van Rossumc524d952001-10-19 01:31:59 +0000754- os and posix supports chroot(), setgroups() and unsetenv() where
755 available. The stat(), fstat(), statvfs() and fstatvfs() functions
756 now return "pseudo-sequences" -- the various fields can now be
757 accessed as attributes (e.g. os.stat("/").st_mtime) but for
758 backwards compatibility they also behave as a fixed-length sequence.
759 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000760 attributes.
761
762- time: localtime(), gmtime() and strptime() now return a
763 pseudo-sequence similar to the os.stat() return value, with
764 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000765
Guido van Rossum9074ef62001-10-16 21:34:49 +0000766- Decompression objects in the zlib module now accept an optional
767 second parameter to decompress() that specifies the maximum amount
768 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000769
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000770- optional SSL support in the socket module now exports OpenSSL
771 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
772 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000773 automatically seed its PRNG. Also, the keyfile and certfile
774 arguments to socket.ssl() are now optional.
775
776- posixmodule (and by extension, the os module on POSIX platforms) now
777 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000778
Guido van Rossum9074ef62001-10-16 21:34:49 +0000779Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000780
Tim Peters7402f792001-10-02 03:53:41 +0000781- doctest now excludes functions and classes not defined by the module
782 being tested, thanks to Tim Hochberg.
783
Fred Drakecb7a6b52001-10-22 18:41:51 +0000784- HotShot, a new profiler implemented using a C-based callback, has
785 been added. This substantially reduces the overhead of profiling,
786 but it is still quite preliminary. Support modules and
787 documentation will be added in upcoming releases (before 2.2 final).
788
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000789- profile now produces correct output in situations where an exception
790 raised in Python is cleared by C code (e.g. hasattr()). This used
791 to cause wrong output, including spurious claims of recursive
792 functions and attribution of time spent to the wrong function.
793
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000794 The code and documentation for the derived OldProfile and HotProfile
795 profiling classes was removed. The code hasn't worked for years (if
796 you tried to use them, they raised exceptions). OldProfile
797 intended to reproduce the behavior of the profiler Python used more
798 than 7 years ago, and isn't interesting anymore. HotProfile intended
799 to provide a faster profiler (but producing less information), and
800 that's a worthy goal we intend to meet via a different approach (but
801 without losing information).
802
Tim Peterscce092d2001-10-09 05:31:56 +0000803- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000804 a much better system-specific calibration constant. The constant can
805 now be specified in an instance constructor, or as a Profile class or
806 instance variable, instead of by editing profile.py's source code.
807 Calibration must still be done manually (see the docs for the profile
808 module).
809
810 Note that Profile.calibrate() must be overriden by subclasses.
811 Improving the accuracy required exploiting detailed knowledge of
812 profiler internals; the earlier method abstracted away the details
813 and measured a simplified model instead, but consequently computed
814 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000815
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000816- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000817 which indicates whether output is intended for the header 'Q'
818 encoding.
819
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000820- The SocketServer.ThreadingMixIn class now closes the request after
821 finish_request() returns. (Not when it errors out though.)
822
Barry Warsawf6fb1712001-10-19 05:35:40 +0000823- The nntplib module's NNTP.body() method has grown a `file' argument
824 to allow saving the message body to a file.
825
826- The email package has added a class email.Parser.HeaderParser which
827 only parses headers and does not recurse into the message's body.
828 Also, the module/class MIMEAudio has been added for representing
829 audio data (contributed by Anthony Baxter).
830
831- ftplib should be able to handle files > 2GB.
832
833- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
834 ON, and OFF.
835
Fred Drakecb7a6b52001-10-22 18:41:51 +0000836- xml.dom.minidom NodeList objects now support the length attribute
837 and item() method as required by the DOM specifications.
838
Guido van Rossumed554f62001-10-02 23:15:37 +0000839Tools/Demos
840
841- Demo/dns was removed. It no longer serves any purpose; a package
842 derived from it is now maintained by Anthony Baxter, see
843 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000844
Barry Warsawf6fb1712001-10-19 05:35:40 +0000845- The freeze tool has been made more robust, and two new options have
846 been added: -X and -E.
847
Tim Petersabf925f2001-09-28 21:53:42 +0000848Build
849
Barry Warsawf6fb1712001-10-19 05:35:40 +0000850- configure will use CXX in LINKCC if CXX is used to build main() and
851 the system requires to link a C++ main using the C++ compiler.
852
Tim Petersabf925f2001-09-28 21:53:42 +0000853C API
854
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000855- The documentation for the tp_compare slot is updated to require that
856 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
857 not correct. This is not yet enforced but will be enforced in
858 Python 2.3; even later, we may use -2 to indicate errors and +2 for
859 "NotImplemented". Right now, -1 should be used for an error return.
860
Tim Petersd38b1c72001-09-30 05:09:37 +0000861- PyLong_AsLongLong() now accepts int (as well as long) arguments.
862 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
863 as long) arguments.
864
Guido van Rossum3c288632001-10-16 21:13:49 +0000865- PyThread_start_new_thread() now returns a long int giving the thread
866 ID, if one can be calculated; it returns -1 for error, 0 if no
867 thread ID is calculated (this is an incompatible change, but only
868 the thread module used this API). This code has only really been
869 tested on Linux and Windows; other platforms please beware (and
870 report any bugs or strange behavior).
871
Guido van Rossum1c486092001-10-19 02:05:35 +0000872- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
873 input.
874
Tim Petersabf925f2001-09-28 21:53:42 +0000875New platforms
876
877Tests
878
879Windows
880
Tim Peters04cf1d32001-10-09 22:39:40 +0000881- Installer: If you install IDLE, and don't disable file-extension
882 registration, a new "Edit with IDLE" context (right-click) menu entry
883 is created for .py and .pyw files.
884
Tim Peters1ce3cf72001-10-01 17:58:40 +0000885- The signal module now supports SIGBREAK on Windows, thanks to Steven
886 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
887 action remains to call Win32 ExitProcess(). This can be changed via
888 signal.signal(). For example:
889
890 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
891 # (SIGINT) behavior.
892 import signal
893 signal.signal(signal.SIGBREAK,
894 signal.default_int_handler)
895
896 try:
897 while 1:
898 pass
899 except KeyboardInterrupt:
900 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
901 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
902 # program without the possibility for any Python-level cleanup).
903 print "Clean exit"
904
Tim Petersabf925f2001-09-28 21:53:42 +0000905
Tim Petersb07352e2001-09-08 01:25:47 +0000906What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000907Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000908===========================
909
Guido van Rossum808eea72001-09-25 04:15:41 +0000910Type/class unification and new-style classes
911
912- pydoc and inspect are now aware of new-style classes;
913 e.g. help(list) at the interactive prompt now shows proper
914 documentation for all operations on list objects.
915
916- Applications using Jim Fulton's ExtensionClass module can now safely
917 be used with Python 2.2. In particular, Zope 2.4.1 now works with
918 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
919 examples also work again. It is hoped that Gtk and Boost also work
920 with 2.2a4 and beyond. (If you can confirm this, please write
921 webmaster@python.org; if there are still problems, please open a bug
922 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000923
Tim Peters66c1a522001-09-24 21:17:50 +0000924- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000925 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +0000926 in the constructed property object. fget, fset and fdel weren't
927 discoverable from Python in 2.2a3. __doc__ is new, and allows to
928 associate a docstring with a property.
929
Guido van Rossum808eea72001-09-25 04:15:41 +0000930- Comparison overloading is now more completely implemented. For
931 example, a str subclass instance can properly be compared to a str
932 instance, and it can properly overload comparison. Ditto for most
933 other built-in object types.
934
935- The repr() of new-style classes has changed; instead of <type
936 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
937 *except* for built-in types, which are still rendered as <type
938 'Foo'> (to avoid upsetting existing code that might parse or
939 otherwise rely on repr() of certain type objects).
940
941- The repr() of new-style objects is now always <Foo object at XXX>;
942 previously, it was sometimes <Foo instance at XXX>.
943
944- For new-style classes, what was previously called __getattr__ is now
945 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000946 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000947 one in classic classes is defined which is called only if regular
948 attribute access raises AttributeError; to catch *all* attribute
949 access, you can use __getattribute__ (for new-style classes). If
950 both are defined, __getattribute__ is called first, and if it raises
951 AttributeError, __getattr__ is called.
952
953- The __class__ attribute of new-style objects can be assigned to.
954 The new class must have the same C-level object layout as the old
955 class.
956
957- The builtin file type can be subclassed now. In the usual pattern,
958 "file" is the name of the builtin type, and file() is a new builtin
959 constructor, with the same signature as the builtin open() function.
960 file() is now the preferred way to open a file.
961
962- Previously, __new__ would only see sequential arguments passed to
963 the type in a constructor call; __init__ would see both sequential
964 and keyword arguments. This made no sense whatsoever any more, so
965 now both __new__ and __init__ see all arguments.
966
967- Previously, hash() applied to an instance of a subclass of str or
968 unicode always returned 0. This has been repaired.
969
970- Previously, an operation on an instance of a subclass of an
971 immutable type (int, long, float, complex, tuple, str, unicode),
972 where the subtype didn't override the operation (and so the
973 operation was handled by the builtin type), could return that
974 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000975 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +0000976 with the same value as s.
977
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000978- Provisional support for pickling new-style objects has been added.
979
Guido van Rossum808eea72001-09-25 04:15:41 +0000980Core
981
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000982- file.writelines() now accepts any iterable object producing strings.
983
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000984- PyUnicode_FromEncodedObject() now works very much like
985 PyObject_Str(obj) in that it tries to use __str__/tp_str
986 on the object if the object is not a string or buffer. This
987 makes unicode() behave like str() when applied to non-string/buffer
988 objects.
989
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000990- PyFile_WriteObject now passes Unicode objects to the file's write
991 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000992 of a print statement must support Unicode objects, i.e. they must
993 at least convert them into ASCII strings.
994
Guido van Rossum624c8af2001-09-18 15:21:04 +0000995- Thread scheduling on Solaris should be improved; it is no longer
996 necessary to insert a small sleep at the start of a thread in order
997 to let other runnable threads be scheduled.
998
Tim Petersb07352e2001-09-08 01:25:47 +0000999Library
1000
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001001- StringIO.StringIO instances and cStringIO.StringIO instances support
1002 read character buffer compatible objects for their .write() methods.
1003 These objects are converted to strings and then handled as such
1004 by the instances.
1005
Barry Warsaw2f600732001-09-24 04:28:10 +00001006- The "email" package has been added. This is basically a port of the
1007 mimelib package <http://sf.net/projects/mimelib> with API changes
1008 and some implementations updated to use iterators and generators.
1009
Tim Peters8a9c2842001-09-22 21:30:22 +00001010- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1011 restores the ability of Tools/scripts/ndiff.py to start producing output
1012 before the entire comparison is complete.
1013
Barry Warsaw58b072d2001-09-22 04:44:21 +00001014- StringIO.StringIO instances and cStringIO.StringIO instances support
1015 iteration just like file objects (i.e. their .readline() method is
1016 called for each iteration until it returns an empty string).
1017
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001018- The codecs module has grown four new helper APIs to access
1019 builtin codecs: getencoder(), getdecoder(), getreader(),
1020 getwriter().
1021
Guido van Rossum624c8af2001-09-18 15:21:04 +00001022- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1023 simplifies writing XML RPC servers.
1024
Barry Warsaw647d5e82001-09-28 17:01:02 +00001025- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001026 after interpretation of symbolic links. On non-Unix systems, this
1027 is an alias for os.path.abspath().
1028
Tim Peters16a77ad2001-09-08 04:00:12 +00001029- operator.indexOf() (PySequence_Index() in the C API) now works with any
1030 iterable object.
1031
Guido van Rossum624c8af2001-09-18 15:21:04 +00001032- smtplib now supports various authentication and security features of
1033 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001034
Guido van Rossum624c8af2001-09-18 15:21:04 +00001035- hmac: a new module implementing keyed hashing for message
1036 authentication.
1037
1038- mimetypes now recognizes more extensions and file types. At the
1039 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001040
Guido van Rossum624c8af2001-09-18 15:21:04 +00001041- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001042 Python 2.2 bytecode generation. It has also been promoted from a
1043 Tool to a standard library package. (Tools/compiler still exists as
1044 a sample driver.)
1045
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001046Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001047
Tim Petersb07352e2001-09-08 01:25:47 +00001048Build
1049
Guido van Rossum624c8af2001-09-18 15:21:04 +00001050- Large file support (LFS) is now automatic when the platform supports
1051 it; no more manual configuration tweaks are needed. On Linux, at
1052 least, it's possible to have a system whose C library supports large
1053 files but whose kernel doesn't; in this case, large file support is
1054 still enabled but doesn't do you any good unless you upgrade your
1055 kernel or share your Python executable with another system whose
1056 kernel has large file support.
1057
1058- The configure script now supplies plausible defaults in a
1059 cross-compilation environment. This doesn't mean that the supplied
1060 values are always correct, or that cross-compilation now works
1061 flawlessly -- but it's a first step (and it shuts up most of
1062 autoconf's warnings about AC_TRY_RUN).
1063
1064- The Unix build is now a bit less chatty, courtesy of the parser
1065 generator. The build is completely silent (except for errors) when
1066 using "make -s", thanks to a -q option to setup.py.
1067
Tim Petersb07352e2001-09-08 01:25:47 +00001068C API
1069
Guido van Rossum624c8af2001-09-18 15:21:04 +00001070- The "structmember" API now supports some new flag bits to deny read
1071 and/or write access to attributes in restricted execution mode.
1072
Tim Petersb07352e2001-09-08 01:25:47 +00001073New platforms
1074
Guido van Rossum624c8af2001-09-18 15:21:04 +00001075- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1076 (http://familiar.handhelds.org).
1077
Tim Petersb07352e2001-09-08 01:25:47 +00001078Tests
1079
Tim Peters8a9c2842001-09-22 21:30:22 +00001080- The "classic" standard tests, which work by comparing stdout to
1081 an expected-output file under Lib/test/output/, no longer stop at
1082 the first mismatch. Instead the test is run to completion, and a
1083 variant of ndiff-style comparison is used to report all differences.
1084 This is much easier to understand than the previous style of reporting.
1085
1086- The unittest-based standard tests now use regrtest's test_main()
1087 convention, instead of running as a side-effect of merely being
1088 imported. This allows these tests to be run in more natural and
1089 flexible ways as unittests, outside the regrtest framework.
1090
1091- regrtest.py is much better integrated with unittest and doctest now,
1092 especially in regard to reporting errors.
1093
Tim Petersb07352e2001-09-08 01:25:47 +00001094Windows
1095
Guido van Rossum624c8af2001-09-18 15:21:04 +00001096- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001097 that support it (NTFS under Windows 2000). See "What's New in
1098 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001099
Tim Petersb07352e2001-09-08 01:25:47 +00001100
Tim Petersedc99312001-08-22 21:36:50 +00001101What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001102Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001103===========================
1104
1105Core
1106
Tim Peters9fffa3e2001-09-04 05:14:19 +00001107- Conversion of long to float now raises OverflowError if the long is too
1108 big to represent as a C double.
1109
Tim Peters32f453e2001-09-03 08:35:41 +00001110- The 3-argument builtin pow() no longer allows a third non-None argument
1111 if either of the first two arguments is a float, or if both are of
1112 integer types and the second argument is negative (in which latter case
1113 the arguments are converted to float, so this is really the same
1114 restriction).
1115
Tim Peters5d2b77c2001-09-03 05:47:38 +00001116- The builtin dir() now returns more information, and sometimes much
1117 more, generally naming all attributes of an object, and all attributes
1118 reachable from the object via its class, and from its class's base
1119 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1120 an empty list. In 2.2a3,
1121
1122 >>> dir([])
1123 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1124 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1125 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1126 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1127 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1128 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1129 'reverse', 'sort']
1130
1131 dir(module) continues to return only the module's attributes, though.
1132
Tim Petersbdee63f2001-09-02 03:40:59 +00001133- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001134 than raising OverflowError. This is a partial implementation of PEP
1135 237. You can use -Wdefault::OverflowWarning to enable a warning for
1136 this situation, and -Werror::OverflowWarning to revert to the old
1137 OverflowError exception.
1138
Guido van Rossum61c345f2001-09-04 03:26:15 +00001139- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001140 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001141 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1142 -Qold, meaning the / operator has its classic meaning and no
1143 warnings are issued. Using -Qwarn issues a run-time warning about
1144 all uses of classic division for int and long arguments; -Qwarnall
1145 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001146 (for use with fixdiv.py).
1147 [Note: the remainder of this paragraph (preserved below) became
1148 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1149 <obsolete>
1150 Using -Qnew is questionable; it turns on new division by default, but
1151 only in the __main__ module. You can usefully combine -Qwarn or
1152 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1153 warns about classic division everywhere else.
1154 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001155
Tim Petersbdee63f2001-09-02 03:40:59 +00001156- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001157 long, float, str, unicode, and tuple. (The types complex, list and
1158 dictionary can also be subclassed; this was introduced earlier.)
1159 Note that restrictions apply when subclassing immutable built-in
1160 types: you can only affect the value of the instance by overloading
1161 __new__. You can add mutable attributes, and the subclass instances
1162 will have a __dict__ attribute, but you cannot change the "value"
1163 (as implemented by the base class) of an immutable subclass instance
1164 once it is created.
1165
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001166- The dictionary constructor now takes an optional argument, a
1167 mapping-like object, and initializes the dictionary from its
1168 (key, value) pairs.
1169
Tim Petersbdee63f2001-09-02 03:40:59 +00001170- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001171 "cooperative super calls" in a multiple inheritance setting. For an
1172 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1173
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001174- A new built-in type, property, has been added. This enables the
1175 creation of "properties". These are attributes implemented by
1176 getter and setter functions (or only one of these for read-only or
1177 write-only attributes), without the need to override __getattr__.
1178 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001179
Tim Petersbdee63f2001-09-02 03:40:59 +00001180- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001181 liberalized, to allow leading zeroes. Examples of literals now
1182 legal that were SyntaxErrors before:
1183
1184 00.0 0e3 0100j 07.5 00000000000000000008.
1185
Tim Petersbdee63f2001-09-02 03:40:59 +00001186- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001187 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1188
Tim Petersedc99312001-08-22 21:36:50 +00001189Library
1190
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001191- telnetlib includes symbolic names for the options, and support for
1192 setting an option negotiation callback.
1193
Tim Petersa40c7932001-09-05 22:36:56 +00001194- The new C standard no longer requires that math libraries set errno to
1195 ERANGE on overflow. For platform libraries that exploit this new
1196 freedom, Python's overflow-checking was wholly broken. A new overflow-
1197 checking scheme attempts to repair that, but may not be reliable on all
1198 platforms (C doesn't seem to provide anything both useful and portable
1199 in this area anymore).
1200
Martin v. Löwis44f86962001-09-05 13:44:54 +00001201- Asynchronous timeout actions are available through the new class
1202 threading.Timer.
1203
Tim Peters78526162001-09-05 00:53:45 +00001204- math.log and math.log10 now return sensible results for even huge
1205 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1206
Tim Petersbdee63f2001-09-02 03:40:59 +00001207- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001208 currently held. See the docs for the imp module.
1209
Tim Petersbdee63f2001-09-02 03:40:59 +00001210- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001211 dumps containing ints written on platforms where Python ints are 8 bytes.
1212 When read on a box where Python ints are 4 bytes, such values are
1213 converted to Python longs.
1214
Tim Petersbdee63f2001-09-02 03:40:59 +00001215- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001216 code objects is no longer allowed. This plugs a security hole.
1217
Steve Purcell6091cd62001-09-06 16:05:17 +00001218- unittest.TestResult instances no longer store references to tracebacks
1219 generated by test failures. This prevents unexpected dangling references
1220 to objects that should be garbage collected between tests.
1221
Tim Petersedc99312001-08-22 21:36:50 +00001222Tools
1223
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001224- Tools/scripts/fixdiv.py has been added which can be used to fix
1225 division operators as per PEP 238.
1226
Tim Petersedc99312001-08-22 21:36:50 +00001227Build
1228
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001229- If you are an adventurous person using Mac OS X you may want to look at
1230 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1231 application, which can be used for experimenting with Carbon or Cocoa.
1232 Discussion of this on pythonmac-sig, please.
1233
Tim Peters7eea37e2001-09-04 22:08:56 +00001234C API
1235
1236- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001237
Tim Peters9fffa3e2001-09-04 05:14:19 +00001238- Note that PyLong_AsDouble can fail! This has always been true, but no
1239 callers checked for it. It's more likely to fail now, because overflow
1240 errors are properly detected now. The proper way to check:
1241
1242 double x = PyLong_AsDouble(some_long_object);
1243 if (x == -1.0 && PyErr_Occurred()) {
1244 /* The conversion failed. */
1245 }
1246
Tim Petersbdee63f2001-09-02 03:40:59 +00001247- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001248 compile but will not participate in GC. To upgrade an extension
1249 module:
1250
1251 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001252
Neil Schemenauer4042c692001-08-30 15:38:01 +00001253 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1254 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001255
Neil Schemenauer4042c692001-08-30 15:38:01 +00001256 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1257 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001258
Neil Schemenauer4042c692001-08-30 15:38:01 +00001259 - remove PyGC_HEAD_SIZE from object size calculations
1260
1261 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1262
Tim Petersbdee63f2001-09-02 03:40:59 +00001263- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001264 These can be used safely to construct string objects from a
1265 sprintf-style format string (similar to the format string supported
1266 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001267
Tim Petersedc99312001-08-22 21:36:50 +00001268New platforms
1269
Tim Petersb7da0902001-09-02 23:01:43 +00001270- Stephen Hansen contributed patches sufficient to get a clean compile
1271 under Borland C (Windows), but he reports problems running it and ran
1272 out of time to complete the port. Volunteers? Expect a MemoryError
1273 when importing the types module; this is probably shallow, and
1274 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001275
Tim Petersedc99312001-08-22 21:36:50 +00001276Tests
1277
1278Windows
1279
Tim Peters6e13a562001-09-06 00:32:15 +00001280- Large file support is now enabled on Win32 platforms as well as on
1281 Win64. This means that, for example, you can use f.tell() and f.seek()
1282 to manipulate files larger than 2 gigabytes (provided you have enough
1283 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001284 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1285 filesize limit, and large file support makes no difference there.
1286 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1287 NTFS has no practical limit on file size, and files of any size can be
1288 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001289
Tim Petersbdee63f2001-09-02 03:40:59 +00001290- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001291 points to command.com (patch from Brian Quinlan).
1292
Tim Petersedc99312001-08-22 21:36:50 +00001293
Tim Peters20f51a72001-07-21 02:31:40 +00001294What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001295Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001296===========================
1297
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001298Build
1299
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001300- Tim Peters developed a brand new Windows installer using Wise 8.1,
1301 generously donated to us by Wise Solutions.
1302
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001303- configure supports a new option --enable-unicode, with the values
1304 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1305 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001306
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001307- A new configure option --enable-framework builds a Mac OS X framework,
1308 which "make frameworkinstall" will install. This provides a starting
1309 point for more mac-like functionality, join pythonmac-sig@python.org
1310 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001311
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001312- The NeXT platform is no longer supported.
1313
1314- The `new' module is now statically linked.
1315
Tim Peters0afb6092001-08-15 06:06:44 +00001316Tools
1317
1318- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001319 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001320 the module docstring for details.
1321
Tim Peters20f51a72001-07-21 02:31:40 +00001322Tests
1323
Tim Peters5e824c32001-08-12 22:25:01 +00001324- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001325 platforms, allowing to give clearer test result output. regrtest
1326 also has optional --use/-u switch to run normally disabled tests
1327 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001328
Tim Peters20f51a72001-07-21 02:31:40 +00001329- Several new tests in the standard test suite, with special thanks to
1330 Nick Mathewson.
1331
1332Core
1333
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001334- The floor division operator // has been added as outlined in PEP
1335 238. The / operator still provides classic division (and will until
1336 Python 3.0) unless "from __future__ import division" is included, in
1337 which case the / operator will provide true division. The operator
1338 module provides truediv() and floordiv() functions. Augmented
1339 assignment variants are included, as are the equivalent overloadable
1340 methods and C API methods. See the PEP for a full discussion:
1341 <http://python.sf.net/peps/pep-0238.html>
1342
Tim Peters6cd6a822001-08-17 22:11:27 +00001343- Future statements are now effective in simulated interactive shells
1344 (like IDLE). This should "just work" by magic, but read Michael
1345 Hudson's "Future statements in simulated shells" PEP 264 for full
1346 details: <http://python.sf.net/peps/pep-0264.html>.
1347
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001348- The type/class unification (PEP 252-253) was integrated into the
1349 trunk and is not so tentative any more (the exact specification of
1350 some features is still tentative). A lot of work has done on fixing
1351 bugs and adding robustness and features (performance still has to
1352 come a long way).
1353
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001354- Warnings about a mismatch in the Python API during extension import
1355 now use the Python warning framework (which makes it possible to
1356 write filters for these warnings).
1357
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001358- A function's __dict__ (aka func_dict) will now always be a
1359 dictionary. It used to be possible to delete it or set it to None,
1360 but now both actions raise TypeErrors. It is still legal to set it
1361 to a dictionary object. Getting func.__dict__ before any attributes
1362 have been assigned now returns an empty dictionary instead of None.
1363
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001364- A new command line option, -E, was added which disables the use of
1365 all environment variables, or at least those that are specifically
1366 significant to Python. Usually those have a name starting with
1367 "PYTHON". This was used to fix a problem where the tests fail if
1368 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1369 older distribution.
1370
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001371Library
1372
Tim Peters5e824c32001-08-12 22:25:01 +00001373- New class Differ and new functions ndiff() and restore() in difflib.py.
1374 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001375 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001376
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001377- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1378 value using the minimal quoting required for the value; more
1379 reliable than using xml.sax.saxutils.escape() for attribute values.
1380
1381- Readline completion support for cmd.Cmd was added.
1382
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001383- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1384
1385- Added function threading.BoundedSemaphore()
1386
1387- Added Ka-Ping Yee's cgitb.py module.
1388
1389- The `new' module now exposes the CO_xxx flags.
1390
Martin v. Löwis560da622001-11-24 09:24:51 +00001391- The gc module offers the get_referents function.
1392
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001393New platforms
1394
1395C API
1396
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001397- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1398 which provide a cross-platform implementations for the
1399 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1400 the standard sprintf() and vsprintf() C lib APIs, these versions
1401 apply bounds checking on the used buffer which enhances protection
1402 against buffer overruns.
1403
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001404- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001405 and extensions using different Unicode widths is rendered next to
1406 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001407 will result in an ImportError. Unicode extensions writers must make
1408 sure to check the Unicode width compatibility in their extensions by
1409 using at least one of the mangled Unicode APIs in the extension.
1410
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001411- Two new flags METH_NOARGS and METH_O are available in method definition
1412 tables to simplify implementation of methods with no arguments and a
1413 single untyped argument. Calling such methods is more efficient than
1414 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1415 deprecated.
1416
Tim Petersc1731372001-08-04 08:12:36 +00001417Windows
1418
1419- "import module" now compiles module.pyw if it exists and nothing else
1420 relevant is found.
1421
Tim Peters20f51a72001-07-21 02:31:40 +00001422
Guido van Rossum55a78992001-07-17 17:22:32 +00001423What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001424Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001425===========================
1426
1427Core
Tim Petersa814db52001-05-14 07:05:58 +00001428
Tim Peters6d6c1a32001-08-02 04:15:00 +00001429- TENTATIVELY, a large amount of code implementing much of what's
1430 described in PEP 252 (Making Types Look More Like Classes) and PEP
1431 253 (Subtyping Built-in Types) was added. This will be released
1432 with Python 2.2a1. Documentation will be provided separately
1433 through http://www.python.org/2.2/. The purpose of releasing this
1434 with Python 2.2a1 is to test backwards compatibility. It is
1435 possible, though not likely, that a decision is made not to release
1436 this code as part of 2.2 final, if any serious backwards
1437 incompapatibilities are found during alpha testing that cannot be
1438 repaired.
1439
Guido van Rossum55a78992001-07-17 17:22:32 +00001440- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001441 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001442 more 'yield' statements. See PEP 255. Since this adds a new
1443 keyword to the language, this feature must be enabled by including a
1444 future statement: "from __future__ import generators" (see PEP 236).
1445 Generators will become a standard feature in a future release
1446 (probably 2.3). Without this future statement, 'yield' remains an
1447 ordinary identifier, but a warning is issued each time it is used.
1448 (These warnings currently don't conform to the warnings framework of
1449 PEP 230; we intend to fix this in 2.2a2.)
1450
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001451- The UTF-16 codec was modified to be more RFC compliant. It will now
1452 only remove BOM characters at the start of the string and then
1453 only if running in native mode (UTF-16-LE and -BE won't remove a
1454 leading BMO character).
1455
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001456- Strings now have a new method .decode() to complement the already
1457 existing .encode() method. These two methods provide direct access
1458 to the corresponding decoders and encoders of the registered codecs.
1459
1460 To enhance the usability of the .encode() method, the special
1461 casing of Unicode object return values was dropped (Unicode objects
1462 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001463
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001464 Both methods will now return whatever the codec in charge of the
1465 requested encoding returns as object, e.g. Unicode codecs will
1466 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1467 will return u"äöü"). This enables codec writer to create codecs
1468 for various simple to use conversions.
1469
1470 New codecs were added to demonstrate these new features (the .encode()
1471 and .decode() columns indicate the type of the returned objects):
1472
1473 Name | .encode() | .decode() | Description
1474 ----------------------------------------------------------------------
1475 uu | string | string | UU codec (e.g. for email)
1476 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001477 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001478 zlib | string | string | zlib compression
1479 hex | string | string | 2-byte hex codec
1480 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1481
Mark Hammond2a0af792001-05-14 03:09:36 +00001482- Some operating systems now support the concept of a default Unicode
1483 encoding for file system operations. Notably, Windows supports 'mbcs'
1484 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001485 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001486 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001487
1488 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001489 functions that return filenames (such as os.listdir()) to return Python
1490 string objects pre-encoded using the default file system encoding for
1491 the platform. As this encoding is likely to be different from Python's
1492 default encoding, converting this name to a Unicode object before passing
1493 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001494 would attempt to use its default encoding (generally ASCII) rather than
1495 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001496
Tim Petersa814db52001-05-14 07:05:58 +00001497 In general, this change simply removes surprises when working with
1498 Unicode and the file system, making these operations work as you expect,
1499 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001500 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001501
Tim Peters61dff2b2001-05-08 15:43:37 +00001502- Float (and complex) literals in source code were evaluated to full
1503 precision only when running from a .py file; the same code loaded from a
1504 .pyc (or .pyo) file could suffer numeric differences starting at about the
1505 12th significant decimal digit. For example, on a machine with IEEE-754
1506 floating arithmetic,
1507
1508 x = 9007199254740992.0
1509 print long(x)
1510
1511 printed 9007199254740992 if run directly from .py, but 9007199254740000
1512 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1513 str(float) instead of repr(float) when building code objects. marshal
1514 now uses repr(float) instead, which should reproduce floats to full
1515 machine precision (assuming the platform C float<->string I/O conversion
1516 functions are of good quality).
1517
1518 This may cause floating-point results to change in some cases, and
1519 usually for the better, but may also cause numerically unstable
1520 algorithms to break.
1521
Tim Peters2f228e72001-05-13 00:19:31 +00001522- The implementation of dicts suffers fewer collisions, which has speed
1523 benefits. However, the order in which dict entries appear in dict.keys(),
1524 dict.values() and dict.items() may differ from previous releases for a
1525 given dict. Nothing is defined about this order, so no program should
1526 rely on it. Nevertheless, it's easy to write test cases that rely on the
1527 order by accident, typically because of printing the str() or repr() of a
1528 dict to an "expected results" file. See Lib/test/test_support.py's new
1529 sortdict(dict) function for a simple way to display a dict in sorted
1530 order.
1531
Tim Peters7a3bfc32001-06-12 01:22:22 +00001532- Many other small changes to dicts were made, resulting in faster
1533 operation along the most common code paths.
1534
Guido van Rossum10315822001-05-01 20:54:30 +00001535- Dictionary objects now support the "in" operator: "x in dict" means
1536 the same as dict.has_key(x).
1537
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001538- The update() method of dictionaries now accepts generic mapping
1539 objects. Specifically the argument object must support the .keys()
1540 and __getitem__() methods. This allows you to say, for example,
1541 {}.update(UserDict())
1542
Guido van Rossum10315822001-05-01 20:54:30 +00001543- Iterators were added; this is a generalized way of providing values
1544 to a for loop. See PEP 234. There's a new built-in function iter()
1545 to return an iterator. There's a new protocol to get the next value
1546 from an iterator using the next() method (in Python) or the
1547 tp_iternext slot (in C). There's a new protocol to get iterators
1548 using the __iter__() method (in Python) or the tp_iter slot (in C).
1549 Iterating (i.e. a for loop) over a dictionary generates its keys.
1550 Iterating over a file generates its lines.
1551
Tim Petersf553f892001-05-01 20:45:31 +00001552- The following functions were generalized to work nicely with iterator
1553 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001554 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001555 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1556 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001557 join() method of strings
1558 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001559 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1560 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001561 right-hand side of assignment statements with multiple targets, such as
1562 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001563
Tim Petersd85e1022001-05-11 21:51:48 +00001564- Accessing module attributes is significantly faster (for example,
1565 random.random or os.path or yourPythonModule.yourAttribute).
1566
Tim Peterse63415e2001-05-08 04:38:29 +00001567- Comparing dictionary objects via == and != is faster, and now works even
1568 if the keys and values don't support comparisons other than ==.
1569
Tim Peters95bf9392001-05-10 08:32:44 +00001570- Comparing dictionaries in ways other than == and != is slower: there were
1571 insecurities in the dict comparison implementation that could cause Python
1572 to crash if the element comparison routines for the dict keys and/or
1573 values mutated the dicts. Making the code bulletproof slowed it down.
1574
Tim Peterseb28ef22001-06-02 05:27:19 +00001575- Collisions in dicts are resolved via a new approach, which can help
1576 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001577 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001578 faster now. Thanks to Christian Tismer for pointing out the cause and
1579 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001580
Tim Peters52e155e2001-06-16 05:42:57 +00001581- repr() is much faster for large containers (dict, list, tuple).
1582
1583
Tim Petersa814db52001-05-14 07:05:58 +00001584Library
1585
Fred Drake960fdf92001-07-20 18:38:26 +00001586- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1587 were added to the string module. These a locale-indenpendent
1588 constants, unlike letters, lowercase, and uppercase. These are now
1589 use in appropriate locations in the standard library.
1590
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001591- The flags used in dlopen calls can now be configured using
1592 sys.setdlopenflags and queried using sys.getdlopenflags.
1593
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001594- Fredrik Lundh's xmlrpclib is now a standard library module. This
1595 provides full client-side XML-RPC support. In addition,
1596 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1597 one asyncore-based). Thanks to Eric Raymond for the documentation.
1598
Guido van Rossum643d3912001-07-05 14:46:25 +00001599- The xrange() object is simplified: it no longer supports slicing,
1600 repetition, comparisons, efficient 'in' checking, the tolist()
1601 method, or the start, stop and step attributes. See PEP 260.
1602
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001603- A new function fnmatch.filter to filter lists of file names was added.
1604
Barry Warsawffd674d2001-05-22 16:00:10 +00001605- calendar.py uses month and day names based on the current locale.
1606
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001607- strop is now *really* obsolete (this was announced before with 1.6),
1608 and issues DeprecationWarning when used (except for the four items
1609 that are still imported into string.py).
1610
Tim Petersa814db52001-05-14 07:05:58 +00001611- Cookie.py now sorts key+value pairs by key in output strings.
1612
1613- pprint.isrecursive(object) didn't correctly identify recursive objects.
1614 Now it does.
1615
Tim Peters95b3f782001-05-14 18:39:41 +00001616- pprint functions now much faster for large containers (tuple, list, dict).
1617
Tim Peters7b9542a2001-06-10 23:40:19 +00001618- New 'q' and 'Q' format codes in the struct module, corresponding to C
1619 types "long long" and "unsigned long long" (on Windows, __int64). In
1620 native mode, these can be used only when the platform C compiler supports
1621 these types (when HAVE_LONG_LONG is #define'd by the Python config
1622 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001623 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1624 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001625
Guido van Rossum83213cc2001-06-12 16:48:52 +00001626- The site module installs a new built-in function 'help' that invokes
1627 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1628 it displays a message reminding the user to use 'help()' or
1629 'help(object)'.
1630
Tim Petersa814db52001-05-14 07:05:58 +00001631Tests
1632
1633- New test_mutants.py runs dict comparisons where the key and value
1634 comparison operators mutute the dicts randomly during comparison. This
1635 rapidly causes Python to crash under earlier releases (not for the faint
1636 of heart: it can also cause Win9x to freeze or reboot!).
1637
1638- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001639 pprint.isreadable() return sensible results. Also verifies that simple
1640 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001641
Tim Peters4324aa32001-05-28 22:30:08 +00001642C API
1643
1644- Removed the unused last_is_sticky argument from the internal
1645 _PyTuple_Resize(). If this affects you, you were cheating.
1646
1647
Guido van Rossum55a78992001-07-17 17:22:32 +00001648======================================================================
1649
1650
Guido van Rossumffe13be2001-04-16 18:46:45 +00001651What's New in Python 2.1 (final)?
1652=================================
1653
1654We only changed a few things since the last release candidate, all in
1655Python library code:
1656
1657- A bug in the locale module was fixed that affected locales which
1658 define no grouping for numeric formatting.
1659
1660- A few bugs in the weakref module's implementations of weak
1661 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1662 and the test suite was updated to check for these bugs.
1663
1664- An old bug in the os.path.walk() function (introduced in Python
1665 2.0!) was fixed: a non-existent file would cause an exception
1666 instead of being ignored.
1667
1668- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1669 PyChecker.
1670
1671
Guido van Rossum5b08f132001-04-16 02:05:23 +00001672What's New in Python 2.1c2?
1673===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001674
Guido van Rossum5b08f132001-04-16 02:05:23 +00001675A flurry of small changes, and one showstopper fixed in the nick of
1676time made it necessary to release another release candidate. The list
1677here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001678
Guido van Rossum5b08f132001-04-16 02:05:23 +00001679Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001680
Guido van Rossum5b08f132001-04-16 02:05:23 +00001681- Tim discovered a nasty bug in the dictionary code, caused by
1682 PyDict_Next() calling dict_resize(), and the GC code's use of
1683 PyDict_Next() violating an assumption in dict_items(). This was
1684 fixed with considerable amounts of band-aid, but the net effect is a
1685 saner and more robust implementation.
1686
1687- Made a bunch of symbols static that were accidentally global.
1688
1689Build and Ports
1690
1691- The setup.py script didn't check for a new enough version of zlib
1692 (1.1.3 is needed). Now it does.
1693
1694- Changed "make clean" target to also remove shared libraries.
1695
1696- Added a more general warning about the SGI Irix optimizer to README.
1697
1698Library
1699
1700- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1701 omitted the slash between host and file.html.
1702
1703- The mailbox module's _Mailbox class contained a completely broken
1704 and undocumented seek() method. Ripped it out.
1705
1706- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1707 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1708
1709- Fixed a few last-minute bugs in unittest.
1710
1711Extensions
1712
1713- Reverted the patch to the OpenSSL code in socketmodule.c to support
1714 RAND_status() and the EGD, and the subsequent patch that tried to
1715 fix it for pre-0.9.5 versions; the problem with the patch is that on
1716 some systems it issues a warning whenever socket is imported, and
1717 that's unacceptable.
1718
1719Tests
1720
1721- Fixed the pickle tests to work with "import test.test_pickle".
1722
1723- Tweaked test_locale.py to actually run the test Windows.
1724
1725- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1726 not "wb" (which is not a valid mode at all).
1727
1728- Fix pstats browser crashes. Import readline if it exists to make
1729 the user interface nicer.
1730
1731- Add "import thread" to the top of test modules that import the
1732 threading module (test_asynchat and test_threadedtempfile). This
1733 prevents test failures caused by a broken threading module resulting
1734 from a previously caught failed import.
1735
1736- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1737 needed on some platforms (e.g. Solaris 8) when the tests are run
1738 twice in succession.
1739
1740- Skip rather than fail test_sunaudiodev if no audio device is found.
1741
1742
1743What's New in Python 2.1c1?
1744===========================
1745
1746This list was significantly updated when 2.1c2 was released; the 2.1c1
1747release didn't mention most changes that were actually part of 2.1c1:
1748
1749Legal
1750
1751- Copyright was assigned to the Python Software Foundation (PSF) and a
1752 PSF license (very similar to the CNRI license) was added.
1753
1754- The CNRI copyright notice was updated to include 2001.
1755
1756Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001757
Guido van Rossumc9932722001-04-12 02:31:27 +00001758- After a public outcry, assignment to __debug__ is no longer illegal;
1759 instead, a warning is issued. It will become illegal in 2.2.
1760
Guido van Rossum5b08f132001-04-16 02:05:23 +00001761- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1762 "%#x" now always prepends "0x", even if the value is zero.
1763
1764- Fixed some nits in the bytecode compiler.
1765
1766- Fixed core dumps when calling certain kinds of non-functions.
1767
1768- Fixed various core dumps caused by reference count bugs.
1769
1770Build and Ports
1771
1772- Use INSTALL_SCRIPT to install script files.
1773
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001774- New port: SCO Unixware 7, by Billy G. Allie.
1775
Guido van Rossum5b08f132001-04-16 02:05:23 +00001776- Updated RISCOS port.
1777
1778- Updated BeOS port and notes.
1779
1780- Various other porting problems resolved.
1781
1782Library
1783
1784- The TERMIOS and SOCKET modules are now truly obsolete and
1785 unnecessary. Their symbols are incorporated in the termios and
1786 socket modules.
1787
1788- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1789 better tests for pickling.
1790
1791- threading: make Condition.wait() robust against KeyboardInterrupt.
1792
1793- zipfile: add support to zipfile to support opening an archive
1794 represented by an open file rather than a file name. Fix bug where
1795 the archive was not properly closed. Fixed a bug in this bugfix
1796 where flush() was called for a read-only file.
1797
1798- imputil: added an uninstall() method to the ImportManager.
1799
1800- Canvas: fixed bugs in lower() and tkraise() methods.
1801
1802- SocketServer: API change (added overridable close_request() method)
1803 so that the TCP server can explicitly close the request.
1804
1805- pstats: Eric Raymond added a simple interactive statistics browser,
1806 invoked when the module is run as a script.
1807
1808- locale: fixed a problem in format().
1809
1810- webbrowser: made it work when the BROWSER environment variable has a
1811 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1812 KDE 2. Fixed some other nits.
1813
1814- unittest: changes to allow using a different exception than
1815 AssertionError, and added a few more function aliases. Some other
1816 small changes.
1817
1818- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1819
1820- asynchat: fixed a critical bug in asynchat that slipped through the
1821 2.1b2 release. Fixed another rare bug.
1822
1823- Fix some unqualified except: clauses (always a bad code example).
1824
1825XML
1826
1827- pyexpat: new API get_version_string().
1828
1829- Fixed some minidom bugs.
1830
1831Extensions
1832
1833- Fixed a core dump in _weakref. Removed the weakref.mapping()
1834 function (it adds nothing to the API).
1835
1836- Rationalized the use of header files in the readline module, to make
1837 it compile (albeit with some warnings) with the very recent readline
1838 4.2, without breaking for earlier versions.
1839
1840- Hopefully fixed a buffering problem in linuxaudiodev.
1841
1842- Attempted a fix to make the OpenSSL support in the socket module
1843 work again with pre-0.9.5 versions of OpenSSL.
1844
1845Tests
1846
1847- Added a test case for asynchat and asyncore.
1848
1849- Removed coupling between tests where one test failing could break
1850 another.
1851
1852Tools
1853
1854- Ping added an interactive help browser to pydoc, fixed some nits
1855 in the rest of the pydoc code, and added some features to his
1856 inspect module.
1857
1858- An updated python-mode.el version 4.1 which integrates Ken
1859 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1860 much nicer in XEmacs and Emacs. When stepping through your program
1861 with pdb, in either the shell window or the *Python* window, the
1862 source file and line will be tracked by an arrow. Very cool!
1863
1864- IDLE: syntax warnings in interactive mode are changed into errors.
1865
1866- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001867 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001868
1869- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001870
Barry Warsaw11e89c72001-04-11 20:37:57 +00001871
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001872What's New in Python 2.1 beta 2?
1873================================
1874
Guido van Rossum053ae352001-03-22 14:17:21 +00001875(Unlisted are many fixed bugs, more documentation, etc.)
1876
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001877Core language, builtins, and interpreter
1878
Guido van Rossum053ae352001-03-22 14:17:21 +00001879- The nested scopes work (enabled by "from __future__ import
1880 nested_scopes") is completed; in particular, the future now extends
1881 into code executed through exec, eval() and execfile(), and into the
1882 interactive interpreter.
1883
1884- When calling a base class method (e.g. BaseClass.__init__(self)),
1885 this is now allowed even if self is not strictly spoken a class
1886 instance (e.g. when using metaclasses or the Don Beaudry hook).
1887
1888- Slice objects are now comparable but not hashable; this prevents
1889 dict[:] from being accepted but meaningless.
1890
1891- Complex division is now calculated using less braindead algorithms.
1892 This doesn't change semantics except it's more likely to give useful
1893 results in extreme cases. Complex repr() now uses full precision
1894 like float repr().
1895
1896- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1897
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001898- It is illegal to assign to the name __debug__, which is set when the
1899 interpreter starts. It is effectively a compile-time constant.
1900
1901- A warning will be issued if a global statement for a variable
1902 follows a use or assignment of that variable.
1903
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001904Standard library
1905
Guido van Rossum053ae352001-03-22 14:17:21 +00001906- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1907 inspired by JUnit), is now part of the standard library. You now
1908 have a choice of two testing frameworks: unittest requires you to
1909 write testcases as separate code, doctest gathers them from
1910 docstrings. Both approaches have their advantages and
1911 disadvantages.
1912
1913- A new module Tix was added, which wraps the Tix extension library
1914 for Tk. With that module, it is not necessary to statically link
1915 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1916 require" command. See Demo/tix/.
1917
1918- tzparse.py is now obsolete.
1919
1920- In gzip.py, the seek() and tell() methods are removed -- they were
1921 non-functional anyway, and it's better if callers can test for their
1922 existence with hasattr().
1923
1924Python/C API
1925
1926- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1927 that's already in the dictionary during a PyDict_Next() iteration.
1928 This used to fail occasionally when a dictionary resize operation
1929 could be triggered that would rehash all the keys. All other
1930 modifications to the dictionary are still off-limits during a
1931 PyDict_Next() iteration!
1932
1933- New extended APIs related to passing compiler variables around.
1934
1935- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1936 implement isinstance() and issubclass().
1937
1938- Py_BuildValue() now has a "D" conversion to create a Python complex
1939 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001940
Fred Drake4e262a92001-03-22 18:26:47 +00001941- Extensions types which support weak references must now set the
1942 field allocated for the weak reference machinery to NULL themselves;
1943 this is done to avoid the cost of checking each object for having a
1944 weakly referencable type in PyObject_INIT(), since most types are
1945 not weakly referencable.
1946
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001947- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1948 free variables and cell variables to and from the frame's f_locals.
1949
1950- Variants of several functions defined in pythonrun.h have been added
1951 to support the nested_scopes future statement. The variants all end
1952 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1953 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1954 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001955 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001956
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001957Distutils
1958
1959- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1960 into the release tree.
1961
Tim Peters0e57abf2001-05-02 07:39:38 +00001962- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001963 (an uninstaller, more customization of the installer's display)
1964
1965- from Jack Jansen: added Mac-specific code to generate a dialog for
1966 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001967 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001968 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001969
1970- added 'platforms' and 'keywords' to the set of metadata that can be
1971 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001972
1973- applied patches from Jason Tishler to make the compiler class work with
1974 Cygwin.
1975
1976
Tim Peters2fe289a2001-03-01 22:19:38 +00001977What's New in Python 2.1 beta 1?
1978================================
Tim Petersd66595f2001-02-04 03:09:53 +00001979
1980Core language, builtins, and interpreter
1981
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001982- Following an outcry from the community about the amount of code
1983 broken by the nested scopes feature introduced in 2.1a2, we decided
1984 to make this feature optional, and to wait until Python 2.2 (or at
1985 least 6 months) to make it standard. The option can be enabled on a
1986 per-module basis by adding "from __future__ import nested_scopes" at
1987 the beginning of a module (before any other statements, but after
1988 comments and an optional docstring). See PEP 236 (Back to the
1989 __future__) for a description of the __future__ statement. PEP 227
1990 (Statically Nested Scopes) has been updated to reflect this change,
1991 and to clarify the semantics in a number of endcases.
1992
1993- The nested scopes code, when enabled, has been hardened, and most
1994 bugs and memory leaks in it have been fixed.
1995
1996- Compile-time warnings are now generated for a number of conditions
1997 that will break or change in meaning when nested scopes are enabled:
1998
1999 - Using "from...import *" or "exec" without in-clause in a function
2000 scope that also defines a lambda or nested function with one or
2001 more free (non-local) variables. The presence of the import* or
2002 bare exec makes it impossible for the compiler to determine the
2003 exact set of local variables in the outer scope, which makes it
2004 impossible to determine the bindings for free variables in the
2005 inner scope. To avoid the warning about import *, change it into
2006 an import of explicitly name object, or move the import* statement
2007 to the global scope; to avoid the warning about bare exec, use
2008 exec...in... (a good idea anyway -- there's a possibility that
2009 bare exec will be deprecated in the future).
2010
2011 - Use of a global variable in a nested scope with the same name as a
2012 local variable in a surrounding scope. This will change in
2013 meaning with nested scopes: the name in the inner scope will
2014 reference the variable in the outer scope rather than the global
2015 of the same name. To avoid the warning, either rename the outer
2016 variable, or use a global statement in the inner function.
2017
Neil Schemenauera35c6882001-02-27 04:45:05 +00002018- An optional object allocator has been included. This allocator is
2019 optimized for Python objects and should be faster and use less memory
2020 than the standard system allocator. It is not enabled by default
2021 because of possible thread safety problems. The allocator is only
2022 protected by the Python interpreter lock and it is possible that some
2023 extension modules require a thread safe allocator. The object
2024 allocator can be enabled by providing the "--with-pymalloc" option to
2025 configure.
2026
Tim Petersd66595f2001-02-04 03:09:53 +00002027Standard library
2028
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002029- pyexpat now detects the expat version if expat.h defines it. A
2030 number of additional handlers are provided, which are only available
2031 since expat 1.95. In addition, the methods SetParamEntityParsing and
2032 GetInputContext of Parser objects are available with 1.95.x
2033 only. Parser objects now provide the ordered_attributes and
2034 specified_attributes attributes. A new module expat.model was added,
2035 which offers a number of additional constants if 1.95.x is used.
2036
2037- xml.dom offers the new functions registerDOMImplementation and
2038 getDOMImplementation.
2039
2040- xml.dom.minidom offers a toprettyxml method. A number of DOM
2041 conformance issues have been resolved. In particular, Element now
2042 has an hasAttributes method, and the handling of namespaces was
2043 improved.
2044
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002045- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2046 getting information about live Python code, and pydoc.py, a module
2047 for interactively converting docstrings to HTML or text.
2048 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002049 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002050 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2051 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002052
Tim Peters1eff7962001-03-01 02:31:33 +00002053- New library module difflib.py, primarily packaging the SequenceMatcher
2054 class at the heart of the popular ndiff.py file-comparison tool.
2055
2056- doctest.py (a framework for verifying Python code examples in docstrings)
2057 is now part of the std library.
2058
Tim Petersd66595f2001-02-04 03:09:53 +00002059Windows changes
2060
Guido van Rossume3955a82001-03-02 14:05:59 +00002061- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2062 small GUI that lets you browse the module docstrings using your
2063 default web browser.
2064
Tim Peters1eff7962001-03-01 02:31:33 +00002065- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2066 Platforms) is implemented. See
2067
2068 http://python.sourceforge.net/peps/pep-0235.html
2069
2070 for full details, especially the "Current Lower-Left Semantics" section.
2071 The new Windows import rules are simpler than before:
2072
2073 A. If the PYTHONCASEOK environment variable exists, same as
2074 before: silently accept the first case-insensitive match of any
2075 kind; raise ImportError if none found.
2076
2077 B. Else search sys.path for the first case-sensitive match; raise
2078 ImportError if none found.
2079
2080 The same rules have been implented on other platforms with case-
2081 insensitive but case-preserving filesystems too (including Cygwin, and
2082 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002083
Tim Peters25a9ce32001-02-19 07:06:36 +00002084- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2085 what it's supposed to do (and does do under NT and 2000) via direct
2086 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002087 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002088 all Win9x systems before.
2089
Tim Peters1eff7962001-03-01 02:31:33 +00002090- Build: Subproject _test (effectively) renamed to _testcapi.
2091
Tim Peters2fe289a2001-03-01 22:19:38 +00002092New platforms
2093
2094- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2095 Thanks to Steven Majewski!
2096
2097- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2098 Tishler!
2099
Guido van Rossum9089b272001-03-02 06:49:50 +00002100- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2101 Schwertberger! See RISCOS/README for more information -- it seems
2102 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002103 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002104
Tim Peters25a9ce32001-02-19 07:06:36 +00002105
Tim Petersd7b5e882001-01-25 03:36:26 +00002106What's New in Python 2.1 alpha 2?
2107=================================
Tim Peters40ead762001-01-27 05:35:26 +00002108
Tim Petersd7b5e882001-01-25 03:36:26 +00002109Core language, builtins, and interpreter
2110
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002111- Scopes nest. If a name is used in a function or class, but is not
2112 local, the definition in the nearest enclosing function scope will
2113 be used. One consequence of this change is that lambda statements
2114 could reference variables in the namespaces where the lambda is
2115 defined. In some unusual cases, this change will break code.
2116
2117 In all previous version of Python, names were resolved in exactly
2118 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002119 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002120 function A is defined within a function B, the names bound in B are
2121 not visible in A. The new rules make names bound in B visible in A,
2122 unless A contains a name binding that hides the binding in B.
2123
2124 Section 4.1 of the reference manual describes the new scoping rules
2125 in detail. The test script in Lib/test/test_scope.py demonstrates
2126 some of the effects of the change.
2127
2128 The new rules will cause existing code to break if it defines nested
2129 functions where an outer function has local variables with the same
2130 name as globals or builtins used by the inner function. Example:
2131
2132 def munge(str):
2133 def helper(x):
2134 return str(x)
2135 if type(str) != type(''):
2136 str = helper(str)
2137 return str.strip()
2138
2139 Under the old rules, the name str in helper() is bound to the
2140 builtin function str(). Under the new rules, it will be bound to
2141 the argument named str and an error will occur when helper() is
2142 called.
2143
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002144- The compiler will report a SyntaxError if "from ... import *" occurs
2145 in a function or class scope. The language reference has documented
2146 that this case is illegal, but the compiler never checked for it.
2147 The recent introduction of nested scope makes the meaning of this
2148 form of name binding ambiguous. In a future release, the compiler
2149 may allow this form when there is no possibility of ambiguity.
2150
Tim Peters40ead762001-01-27 05:35:26 +00002151- repr(string) is easier to read, now using hex escapes instead of octal,
2152 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2153
2154 >>> "\texample \r\n" + chr(0) + chr(255)
2155 '\texample \r\n\x00\xff' # in 2.1
2156 '\011example \015\012\000\377' # in 2.0
2157
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002158- Functions are now compared and hashed by identity, not by value, since
2159 the func_code attribute is writable.
2160
Fred Drakefb9d7122001-02-01 20:00:40 +00002161- Weak references (PEP 205) have been added. This involves a few
2162 changes in the core, an extension module (_weakref), and a Python
2163 module (weakref). The weakref module is the public interface. It
2164 includes support for "explicit" weak references, proxy objects, and
2165 mappings with weakly held values.
2166
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002167- A 'continue' statement can now appear in a try block within the body
2168 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002169 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002170
Tim Petersd7b5e882001-01-25 03:36:26 +00002171Standard library
2172
Barry Warsaw30dbd142001-01-31 22:14:01 +00002173- mailbox.py now has a new class, PortableUnixMailbox which is
2174 identical to UnixMailbox but uses a more portable scheme for
2175 determining From_ separators. Also, the constructors for all the
2176 classes in this module have a new optional `factory' argument, which
2177 is a callable used when new message classes must be instantiated by
2178 the next() method.
2179
Tim Petersd7b5e882001-01-25 03:36:26 +00002180- random.py is now self-contained, and offers all the functionality of
2181 the now-deprecated whrandom.py. See the docs for details. random.py
2182 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002183 and restoring the internal state of the generator; and jumpahead(n),
2184 for quickly forcing the internal state to be the same as if n calls to
2185 random() had been made. The latter is particularly useful for multi-
2186 threaded programs, creating one instance of the random.Random() class for
2187 each thread, then using .jumpahead() to force each instance to use a
2188 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002189
Tim Peters0de88fc2001-02-01 04:59:18 +00002190- random.py's seed() function is new. For bit-for-bit compatibility with
2191 prior releases, use the whseed function instead. The new seed function
2192 addresses two problems: (1) The old function couldn't produce more than
2193 about 2**24 distinct internal states; the new one about 2**45 (the best
2194 that can be done in the Wichmann-Hill generator). (2) The old function
2195 sometimes produced identical internal states when passed distinct
2196 integers, and there was no simple way to predict when that would happen;
2197 the new one guarantees to produce distinct internal states for all
2198 arguments in [0, 27814431486576L).
2199
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002200- The socket module now supports raw packets on Linux. The socket
2201 family is AF_PACKET.
2202
Tim Peters9ea17ac2001-02-02 05:57:15 +00002203- test_capi.py is a start at running tests of the Python C API. The tests
2204 are implemented by the new Modules/_testmodule.c.
2205
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002206- A new extension module, _symtable, provides provisional access to the
2207 internal symbol table used by the Python compiler. A higher-level
2208 interface will be added on top of _symtable in a future release.
2209
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002210- Removed the obsolete soundex module.
2211
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002212- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2213 the isSameNode method; NamedNodeMap the get method.
2214
2215- xml.sax.expatreader supports the lexical handler property; it
2216 generates comment, startCDATA, and endCDATA events.
2217
Tim Petersee826f82001-01-31 19:39:44 +00002218Windows changes
2219
2220- Build procedure: the zlib project is built in a different way that
2221 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002222 the zlib binary used. See PCbuild\readme.txt for details. Your old
2223 zlib-related directories can be deleted; you'll need to download fresh
2224 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002225
Tim Peters9ea17ac2001-02-02 05:57:15 +00002226- Build: New subproject _test for the benefit of test_capi.py (see above).
2227
Tim Petersb16c56f2001-02-02 21:24:51 +00002228- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2229 interface to some Python compiler internals).
2230
2231- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002232 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002233
Tim Petersa3a3a032000-11-30 05:22:44 +00002234What's New in Python 2.1 alpha 1?
2235=================================
2236
2237Core language, builtins, and interpreter
2238
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002239- There is a new Unicode companion to the PyObject_Str() API
2240 called PyObject_Unicode(). It behaves in the same way as the
2241 former, but assures that the returned value is an Unicode object
2242 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002243
Guido van Rossumf98eda02001-01-17 15:54:45 +00002244- The comparison operators support "rich comparison overloading" (PEP
2245 207). C extension types can provide a rich comparison function in
2246 the new tp_richcompare slot in the type object. The cmp() function
2247 and the C function PyObject_Compare() first try the new rich
2248 comparison operators before trying the old 3-way comparison. There
2249 is also a new C API PyObject_RichCompare() (which also falls back on
2250 the old 3-way comparison, but does not constrain the outcome of the
2251 rich comparison to a Boolean result).
2252
2253 The rich comparison function takes two objects (at least one of
2254 which is guaranteed to have the type that provided the function) and
2255 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2256 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2257 object, which may be NotImplemented (in which case the tp_compare
2258 slot function is used as a fallback, if defined).
2259
2260 Classes can overload individual comparison operators by defining one
2261 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002262 __ge__. There are no explicit "reflected argument" versions of
2263 these; instead, __lt__ and __gt__ are each other's reflection,
2264 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2265 reflection (similar at the C level). No other implications are
2266 made; in particular, Python does not assume that == is the Boolean
2267 inverse of !=, or that < is the Boolean inverse of >=. This makes
2268 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002269
2270 Classes or types that want to implement (in)equality tests but not
2271 the ordering operators (i.e. unordered types) should implement ==
2272 and !=, and raise an error for the ordering operators.
2273
Guido van Rossuma88479f2001-01-18 14:28:08 +00002274 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002275 Boolean; e.g. a matrix type might want to return a matrix of bits
2276 for A < B, giving elementwise comparisons. Such types should ensure
2277 that any interpretation of their value in a Boolean context raises
2278 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2279 at the C level) to always raise an exception.
2280
Guido van Rossuma88479f2001-01-18 14:28:08 +00002281- Complex numbers use rich comparisons to define == and != but raise
2282 an exception for <, <=, > and >=. Unfortunately, this also means
2283 that cmp() of two complex numbers raises an exception when the two
2284 numbers differ. Since it is not mathematically meaningful to compare
2285 complex numbers except for equality, I hope that this doesn't break
2286 too much code.
2287
Tim Peters3389f192001-02-18 08:48:49 +00002288- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002289 not defined by the language, other than that it's arbitrary but
2290 consistent (see the Reference Manual). An implementation detail changed
2291 in 2.1a1 such that None now compares less than any other object. Code
2292 relying on this new behavior (like code that relied on the previous
2293 behavior) does so at its own risk.
2294
Barry Warsaw573b5412001-01-15 20:43:18 +00002295- Functions and methods now support getting and setting arbitrarily
2296 named attributes (PEP 232). Functions have a new __dict__
2297 (a.k.a. func_dict) which hold the function attributes. Methods get
2298 and set attributes on their underlying im_func. It is a TypeError
2299 to set an attribute on a bound method.
2300
Guido van Rossum051e3352001-01-15 19:11:10 +00002301- The xrange() object implementation has been improved so that
2302 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2303 limitation that in this case len(xrange(sys.maxint)) can't be
2304 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2305 work fine as long as the index i doesn't actually reach 2**31.
2306 (Python uses regular ints for sequence and string indices; fixing
2307 that is much more work.)
2308
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002309- Two changes to from...import:
2310
Guido van Rossumba381232001-02-03 15:06:40 +00002311 1) "from M import X" now works even if (after loading module M)
2312 sys.modules['M'] is not a real module; it's basically a getattr()
2313 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002314
2315 2) "from M import *" now looks for M.__all__ to decide which names to
2316 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2317 filters out names starting with '_' as before. Whether or not
2318 __all__ exists, there's no restriction on the type of M.
2319
Guido van Rossumf61f1662001-01-10 20:13:55 +00002320- File objects have a new method, xreadlines(). This is the fastest
2321 way to iterate over all lines in a file:
2322
2323 for line in file.xreadlines():
2324 ...do something to line...
2325
2326 See the xreadlines module (mentioned below) for how to do this for
2327 other file-like objects.
2328
2329- Even if you don't use file.xreadlines(), you may expect a speedup on
2330 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002331 quite a bit in platform-specific ways: on systems (like Linux) that
2332 support flockfile(), getc_unlocked(), and funlockfile(), those are
2333 used by default. On systems (like Windows) without getc_unlocked(),
2334 a complicated (but still thread-safe) method using fgets() is used by
2335 default.
2336
Tim Petersd52269b2001-01-25 06:23:18 +00002337 You can force use of the fgets() method by #define'ing
2338 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002339 getc_unlocked()).
2340
Tim Petersd52269b2001-01-25 06:23:18 +00002341 You can force fgets() not to be used by #define'ing
2342 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002343 test_bufio.py fails -- and let us know if it does!).
2344
2345- In addition, the fileinput module, while still slower than the other
2346 methods on most platforms, has been sped up too, by using
2347 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002348
2349- Support for run-time warnings has been added, including a new
2350 command line option (-W) to specify the disposition of warnings.
2351 See the description of the warnings module below.
2352
2353- Extensive changes have been made to the coercion code. This mostly
2354 affects extension modules (which can now implement mixed-type
2355 numerical operators without having to use coercion), but
2356 occasionally, in boundary cases the coercion semantics have changed
2357 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002358 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002359 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002360 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002361
Guido van Rossumf98eda02001-01-17 15:54:45 +00002362- In connection with the coercion changes, a new built-in singleton
2363 object, NotImplemented is defined. This can be returned for
2364 operations that wish to indicate they are not implemented for a
2365 particular combination of arguments. From C, this is
2366 Py_NotImplemented.
2367
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002368- The interpreter accepts now bytecode files on the command line even
2369 if they do not have a .pyc or .pyo extension. On Linux, after executing
2370
Martin v. Löwise214baa2001-02-04 22:37:56 +00002371import imp,sys,string
2372magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2373reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2374open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002375
2376 any byte code file can be used as an executable (i.e. as an argument
2377 to execve(2)).
2378
Tim Peters9940b802000-12-01 07:59:35 +00002379- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002380 character. In 1.6 and earlier, they never produced a sign,
2381 and raised an error if the value of the long was too large
2382 to fit in a Python int. In 2.0, they produced a sign if and
2383 only if too large to fit in an int. This was inconsistent
2384 across platforms (because the size of an int varies across
2385 platforms), and inconsistent with hex() and oct(). Example:
2386
2387 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002388 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002389 'ffffffbe' # in 2.0 and before, on 32-bit machines
2390 >>> hex(-0x42L)
2391 '-0x42L' # in all versions of Python
2392
Tim Peters9940b802000-12-01 07:59:35 +00002393 The behavior of %d formats for negative Python longs remains
2394 the same as in 2.0 (although in 1.6 and before, they raised
2395 an error if the long didn't fit in a Python int).
2396
2397 %u formats don't make sense for Python longs, but are allowed
2398 and treated the same as %d in 2.1. In 2.0, a negative long
2399 formatted via %u produced a sign if and only if too large to
2400 fit in an int. In 1.6 and earlier, a negative long formatted
2401 via %u raised an error if it was too big to fit in an int.
2402
Guido van Rossum3661d392000-12-12 22:10:31 +00002403- Dictionary objects have an odd new method, popitem(). This removes
2404 an arbitrary item from the dictionary and returns it (in the form of
2405 a (key, value) pair). This can be useful for algorithms that use a
2406 dictionary as a bag of "to do" items and repeatedly need to pick one
2407 item. Such algorithms normally end up running in quadratic time;
2408 using popitem() they can usually be made to run in linear time.
2409
Tim Peters36cdad12000-12-29 02:06:45 +00002410Standard library
2411
Thomas Woutersfe385252001-01-19 23:16:56 +00002412- In the time module, the time argument to the functions strftime,
2413 localtime, gmtime, asctime and ctime is now optional, defaulting to
2414 the current time (in the local timezone).
2415
Guido van Rossumda91f222001-01-15 16:36:08 +00002416- The ftplib module now defaults to passive mode, which is deemed a
2417 more useful default given that clients are often inside firewalls
2418 these days. Note that this could break if ftplib is used to connect
2419 to a *server* that is inside a firewall, from outside; this is
2420 expected to be a very rare situation. To fix that, you can call
2421 ftp.set_pasv(0).
2422
Martin v. Löwis10a27872001-01-13 09:54:41 +00002423- The module site now treats .pth files not only for path configuration,
2424 but also supports extensions to the initialization code: Lines starting
2425 with import are executed.
2426
Guido van Rossumf61f1662001-01-10 20:13:55 +00002427- There's a new module, warnings, which implements a mechanism for
2428 issuing and filtering warnings. There are some new built-in
2429 exceptions that serve as warning categories, and a new command line
2430 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2431 turns warnings into errors). warnings.warn(message[, category])
2432 issues a warning message; this can also be called from C as
2433 PyErr_Warn(category, message).
2434
2435- A new module xreadlines was added. This exports a single factory
2436 function, xreadlines(). The intention is that this code is the
2437 absolutely fastest way to iterate over all lines in an open
2438 file(-like) object:
2439
2440 import xreadlines
2441 for line in xreadlines.xreadlines(file):
2442 ...do something to line...
2443
2444 This is equivalent to the previous the speed record holder using
2445 file.readlines(sizehint). Note that if file is a real file object
2446 (as opposed to a file-like object), this is equivalent:
2447
2448 for line in file.xreadlines():
2449 ...do something to line...
2450
Tim Peters36cdad12000-12-29 02:06:45 +00002451- The bisect module has new functions bisect_left, insort_left,
2452 bisect_right and insort_right. The old names bisect and insort
2453 are now aliases for bisect_right and insort_right. XXX_right
2454 and XXX_left methods differ in what happens when the new element
2455 compares equal to one or more elements already in the list: the
2456 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002457 right. Code that doesn't care where equal elements end up should
2458 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002459
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002460- The new curses.panel module wraps the panel library that forms part
2461 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2462
Guido van Rossumf61f1662001-01-10 20:13:55 +00002463- The SocketServer module now sets the allow_reuse_address flag by
2464 default in the TCPServer class.
2465
2466- A new function, sys._getframe(), returns the stack frame pointer of
2467 the caller. This is intended only as a building block for
2468 higher-level mechanisms such as string interpolation.
2469
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002470- The pyexpat module supports a number of new handlers, which are
2471 available only in expat 1.2. If invocation of a callback fails, it
2472 will report an additional frame in the traceback. Parser objects
2473 participate now in garbage collection. If expat reports an unknown
2474 encoding, pyexpat will try to use a Python codec; that works only
2475 for single-byte charsets. The parser type objects is exposed as
2476 XMLParserObject.
2477
2478- xml.dom now offers standard definitions for symbolic node type and
2479 exception code constants, and a hierarchy of DOM exceptions. minidom
2480 was adjusted to use them.
2481
2482- The conformance of xml.dom.minidom to the DOM specification was
2483 improved. It detects a number of additional error cases; the
2484 previous/next relationship works even when the tree is modified;
2485 Node supports the normalize() method; NamedNodeMap, DocumentType and
2486 DOMImplementation classes were added; Element supports the
2487 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2488 method.
2489
Guido van Rossumf61f1662001-01-10 20:13:55 +00002490Build issues
2491
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002492- For Unix (and Unix-compatible) builds, configuration and building of
2493 extension modules is now greatly automated. Rather than having to
2494 edit the Modules/Setup file to indicate which modules should be
2495 built and where their include files and libraries are, a
2496 distutils-based setup.py script now takes care of building most
2497 extension modules. All extension modules built this way are built
2498 as shared libraries. Only a few modules that must be linked
2499 statically are still listed in the Setup file; you won't need to
2500 edit their configuration.
2501
2502- Python should now build out of the box on Cygwin. If it doesn't,
2503 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002504
2505- Python now always uses its own (renamed) implementation of getopt()
2506 -- there's too much variation among C library getopt()
2507 implementations.
2508
2509- C++ compilers are better supported; the CXX macro is always set to a
2510 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002511
Tim Petersd92dfe02000-12-12 01:18:41 +00002512Windows changes
2513
2514- select module: By default under Windows, a select() call
2515 can specify no more than 64 sockets. Python now boosts
2516 this Microsoft default to 512. If you need even more than
2517 that, see the MS docs (you'll need to #define FD_SETSIZE
2518 and recompile Python from source).
2519
Guido van Rossumf61f1662001-01-10 20:13:55 +00002520- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2521 subdirectory is no more!
2522
Tim Petersa3a3a032000-11-30 05:22:44 +00002523
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002524What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002525=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002526
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002527Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002528changes are in the file HISTORY. If you are making the jump directly
2529from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2530HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002531
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002532Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2533the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2534http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002535
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002536--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002537
2538======================================================================
2539
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002540What's new in 2.0 (since release candidate 1)?
2541==============================================
2542
2543Standard library
2544
2545- The copy_reg module was modified to clarify its intended use: to
2546 register pickle support for extension types, not for classes.
2547 pickle() will raise a TypeError if it is passed a class.
2548
2549- Fixed a bug in gettext's "normalize and expand" code that prevented
2550 it from finding an existing .mo file.
2551
2552- Restored support for HTTP/0.9 servers in httplib.
2553
Tim Peters989b7b92000-10-16 20:24:53 +00002554- The math module was changed to stop raising OverflowError in case of
2555 underflow, and return 0 instead in underflow cases. Whether Python
2556 used to raise OverflowError in case of underflow was platform-
2557 dependent (it did when the platform math library set errno to ERANGE
2558 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002559
2560- Fixed a bug in StringIO that occurred when the file position was not
2561 at the end of the file and write() was called with enough data to
2562 extend past the end of the file.
2563
2564- Fixed a bug that caused Tkinter error messages to get lost on
2565 Windows. The bug was fixed by replacing direct use of
2566 interp->result with Tcl_GetStringResult(interp).
2567
2568- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2569 redirect response.
2570
2571- Several changes were made to distutils: Some debugging code was
2572 removed from util. Fixed the installer used when an external zip
2573 program (like WinZip) is not found; the source code for this
2574 installer is in Misc/distutils. check_lib() was modified to behave
2575 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2576 test for whether installed modules are on sys.path was changed to
2577 use both normcase() and normpath().
2578
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002579- Several minor bugs were fixed in the xml package (the minidom,
2580 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002581
2582- The regression test driver (regrtest.py) behavior when invoked with
2583 -l changed: It now reports a count of objects that are recognized as
2584 garbage but not freed by the garbage collector.
2585
Tim Peters989b7b92000-10-16 20:24:53 +00002586- The regression test for the math module was changed to test
2587 exceptional behavior when the test is run in verbose mode. Python
2588 cannot yet guarantee consistent exception behavior across platforms,
2589 so the exception part of test_math is run only in verbose mode, and
2590 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002591
2592Internals
2593
2594- PyOS_CheckStack() has been disabled on Win64, where it caused
2595 test_sre to fail.
2596
2597Build issues
2598
2599- Changed compiler flags, so that gcc is always invoked with -Wall and
2600 -Wstrict-prototypes. Users compiling Python with GCC should see
2601 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002602 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002603 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002604
Tim Petersa3a3a032000-11-30 05:22:44 +00002605- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002606
2607Tools and other miscellany
2608
2609- The compiler in Tools/compiler was updated to support the new
2610 language features introduced in 2.0: extended print statement, list
2611 comprehensions, and augmented assignments. The new compiler should
2612 also be backwards compatible with Python 1.5.2; the compiler will
2613 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002614 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002615
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002616What's new in 2.0 release candidate 1 (since beta 2)?
2617=====================================================
2618
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002619What is release candidate 1?
2620
2621We believe that release candidate 1 will fix all known bugs that we
2622intend to fix for the 2.0 final release. This release should be a bit
2623more stable than the previous betas. We would like to see even more
2624widespread testing before the final release, so we are producing this
2625release candidate. The final release will be exactly the same unless
2626any show-stopping (or brown bag) bugs are found by testers of the
2627release candidate.
2628
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002629All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002630to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002631
2632Core language, builtins, and interpreter
2633
2634- A bug that caused crashes when __coerce__ was used with augmented
2635 assignment, e.g. +=, was fixed.
2636
2637- Raise ZeroDivisionError when raising zero to a negative number,
2638 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2639 power operator and the result of math.pow(0.0, -2.0) will vary by
2640 platform. On Linux, it raises a ValueError.
2641
2642- A bug in Unicode string interpolation was fixed that occasionally
2643 caused errors with formats including "%%". For example, the
2644 following expression "%% %s" % u"abc" no longer raises a TypeError.
2645
2646- Compilation of deeply nested expressions raises MemoryError instead
2647 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2648
2649- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2650 rendering them useless. They are now written in binary mode again.
2651
2652Standard library
2653
2654- Keyword arguments are now accepted for most pattern and match object
2655 methods in SRE, the standard regular expression engine.
2656
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002657- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002658 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002659
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002660- Several bugs in the Unicode handling and error handling in _tkinter
2661 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002662
2663- Fix memory management errors in Merge() and Tkapp_Call() routines.
2664
2665- Several changes were made to cStringIO to make it compatible with
2666 the file-like object interface and with StringIO. If operations are
2667 performed on a closed object, an exception is raised. The truncate
2668 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002669 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002670
2671- There were many changes made to the linuxaudiodev module and its
2672 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002673 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002674
2675 Note that this module is named poorly, because it should work
2676 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002677 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002678
2679 The module now raises exceptions when errors occur instead of
2680 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2681 audio) and defines a getptr() method that calls the
2682 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2683
2684- The library_version attribute, introduced in an earlier beta, was
2685 removed because it can not be supported with early versions of the C
2686 readline library, which provides no way to determine the version at
2687 compile-time.
2688
2689- The binascii module is now enabled on Win64.
2690
Tim Peters46446d62000-10-09 21:19:31 +00002691- tokenize.py no longer suffers "recursion depth" errors when parsing
2692 programs with very long string literals.
2693
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002694Internals
2695
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002696- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002697 which is called when the interpreter starts up to determine where
2698 the standard library is installed. These vulnerabilities affect all
2699 previous versions of Python and can be exploited by setting very
2700 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2701 setuid Python script, although use of the wrapper in
2702 Misc/setuid-prog.c will eliminate the vulnerability.
2703
2704- Fixed garbage collection bugs in instance creation that were
2705 triggered when errors occurred during initialization. The solution,
2706 applied in cPickle and in PyInstance_New(), is to call
2707 PyObject_GC_Init() after the initialization of the object's
2708 container attributes is complete.
2709
2710- pyexpat adds definitions of PyModule_AddStringConstant and
2711 PyModule_AddObject if the Python version is less than 2.0, which
2712 provides compatibility with PyXML on Python 1.5.2.
2713
2714- If the platform has a bogus definition for LONG_BIT (the number of
2715 bits in a long), an error will be reported at compile time.
2716
2717- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2718 collection crashes and possibly other, unreported crashes.
2719
2720- Fixed a memory leak in _PyUnicode_Fini().
2721
2722Build issues
2723
2724- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002725 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002726 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002727
2728- The mmap.PAGESIZE constant is now initialized using sysconf when
2729 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2730
2731- The md5 file should now compile on all platforms.
2732
2733- The select module now compiles on platforms that do not define
2734 POLLRDNORM and related constants.
2735
2736- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002737 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002738
Jeremy Hylton10921202000-10-09 18:34:12 +00002739- BeOS: A number of changes were made to the build and installation
2740 process. ar-fake now operates on a directory of object files.
2741 dl_export.h is gone, and its macros now appear on the mwcc command
2742 line during build on PPC BeOS.
2743
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002744- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002745 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002746
2747- Cygwin: Support for shared libraries, Tkinter, and sockets.
2748
2749- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2750
2751Tools and other miscellany
2752
2753- Removed debugging prints from main used with freeze.
2754
Tim Peters46446d62000-10-09 21:19:31 +00002755- IDLE auto-indent no longer crashes when it encounters Unicode
2756 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002757
2758What's new in 2.0 beta 2 (since beta 1)?
2759========================================
2760
2761Core language, builtins, and interpreter
2762
Tim Peters482c0212000-09-26 06:33:09 +00002763- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002764 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002765
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002766- Add -h and -V command line options to print the usage message and
2767 Python version number and exit immediately.
2768
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002769- eval() and exec accept Unicode objects as code parameters.
2770
2771- getattr() and setattr() now also accept Unicode objects for the
2772 attribute name, which are converted to strings using the default
2773 encoding before lookup.
2774
2775- Multiplication on string and Unicode now does proper bounds
2776 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2777 string is too long."
2778
2779- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002780 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002781
Jeremy Hylton1b618592000-09-26 05:32:36 +00002782
2783Standard library and extensions
2784
Guido van Rossum5b08f132001-04-16 02:05:23 +00002785- socket module: the OpenSSL code now adds support for RAND_status()
2786 and EGD (Entropy Gathering Device).
2787
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002788- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002789 argument checking; it still takes no arguments.
2790
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002791- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002792
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002793- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002794
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002795- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002796
2797- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002799
2800- copy: Copy Unicode objects atomically.
2801
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002802- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002803
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002804- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002805
Fred Drake67233bc2000-09-26 16:40:27 +00002806- dbm: Add get() and setdefault() methods to dbm object. Add constant
2807 `library' to module that names the library used. Added doc strings
2808 and method names to error messages. Uses configure to determine
2809 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2810 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002811
2812- distutils: Update to version 0.9.3.
2813
2814- dl: Add several dl.RTLD_ constants.
2815
2816- fpectl: Now supported on FreeBSD.
2817
2818- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2819 found by the collector will be saved in gc.garbage. This is useful
2820 for debugging a program that creates reference cycles.
2821
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002822- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002823 of HTTP class. Do not close socket on zero-length response. Do not
2824 crash when server sends invalid content-length header.
2825
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002826- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002827
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002828- marshal: When reading a short, sign-extend on platforms where shorts
2829 are bigger than 16 bits. When reading a long, repair the unportable
2830 sign extension that was being done for 64-bit machines. (It assumed
2831 that signed right shift sign-extends.)
2832
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002833- operator: Add contains(), invert(), __invert__() as aliases for
2834 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002835
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002836- os: Add support for popen2() and popen3() on all platforms where
2837 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002838
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002839- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002840 clicking on a file in Explorer (or passing the file name to the
2841 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002842
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002843- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002844 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002845
2846- pickle: Now raises ValueError when an invalid pickle that contains
2847 a non-string repr where a string repr was expected. This behavior
2848 matches cPickle.
2849
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002850- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002851
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002852- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002853
2854- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002855 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002856 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002857
2858- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002859 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002860
2861- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002862 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002863 few cycles during startup since the first call to
2864 setdefaultencoding() will initialize the codec registry and the
2865 encodings package.
2866
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002867- socket: Support for size hint in readlines() method of object returned
2868 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002869
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002870- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002871 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002872 is followed by whitespace.
2873
Tim Petersa3a3a032000-11-30 05:22:44 +00002874- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002875
2876- struct: Check ranges for bytes and shorts.
2877
2878- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002879 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002880
2881- Tkinter: Image objects are now guaranteed to have unique ids. Set
2882 event.delta to zero if Tk version doesn't support mousewheel.
2883 Removed some debugging prints.
2884
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002885- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002886
Fred Drake67233bc2000-09-26 16:40:27 +00002887- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002888 which works around a bug in Norton AntiVirus 2000 that leads directly
2889 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002890
2891- xml: New version detection code allows PyXML to override standard
2892 XML package if PyXML version is greater than 0.6.1.
2893
Fred Drake64bb3802000-09-26 16:21:35 +00002894- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2895 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2896 tree only for nodes which are sufficiently interesting to a specific
2897 application. Does not provide the HTML-specific extensions. Still
2898 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899
Fred Drake64bb3802000-09-26 16:21:35 +00002900- xml.sax: SAX 2 support for Python, including all the handler
2901 interfaces needed to process XML 1.0 compliant XML. Some
2902 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002903
Fred Drake64bb3802000-09-26 16:21:35 +00002904- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2905 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002906
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002907
Jeremy Hylton1b618592000-09-26 05:32:36 +00002908C API
2909
2910- Add three new convenience functions for module initialization --
2911 PyModule_AddObject(), PyModule_AddIntConstant(), and
2912 PyModule_AddStringConstant().
2913
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002914- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002915 removed and add #error to Python.h if NULL isn't defined after
2916 #include of stdio.h.
2917
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002918- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002919 backwards compatibility (at the source level) with old extensions.
2920
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002921- A wrapper API was added for signal() and sigaction(). Instead of
2922 either function, always use PyOS_getsig() to get a signal handler
2923 and PyOS_setsig() to set one. A new convenience typedef
2924 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002925
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002926- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002927 internal data buffer and size of a string object -- or the default
2928 encoded version of a Unicode object.
2929
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002930- PyString_Size() and PyString_AsString() accept Unicode objects.
2931
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002932- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002933 exists). INT_MAX and LONG_MAX will always be defined, even if
2934 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002935
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002936- PyFloat_FromString takes a second argument, pend, that was
2937 effectively useless. It is now officially useless but preserved for
2938 backwards compatibility. If the pend argument is not NULL, *pend is
2939 set to NULL.
2940
2941- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2942 for the attribute name. See note on getattr() above.
2943
2944- A few bug fixes to argument processing for Unicode.
2945 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2946 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2947 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002948 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002949
2950- Py_BuildValue accepts B format (for bgen-generated code).
2951
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002952
Jeremy Hylton1b618592000-09-26 05:32:36 +00002953Internals
2954
2955- On Unix, fix code for finding Python installation directory so that
2956 it works when argv[0] is a relative path.
2957
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002958- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002959 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002960 rather than by generating a copy of the object.
2961
Tim Peters482c0212000-09-26 06:33:09 +00002962- Several of the internal Unicode tables are much smaller now, and
2963 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002964
Jeremy Hylton97693b02000-09-26 17:42:51 +00002965- In the garbage collector: Fixed bug in collection of tuples. Fixed
2966 bug that caused some instances to be removed from the container set
2967 while they were still live. Fixed parsing in gc.set_debug() for
2968 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002969
2970- Fixed refcount problem in instance deallocation that only occurred
2971 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2972
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002973- On Windows, getpythonregpath is now protected against null data in
2974 registry key.
2975
2976- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002977 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002978
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002979
Jeremy Hylton1b618592000-09-26 05:32:36 +00002980Build and platform-specific issues
2981
2982- Better support of GNU Pth via --with-pth configure option.
2983
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002984- Python/C API now properly exposed to dynamically-loaded extension
2985 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002986
2987- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2988 Don't define MS_SYNC to be zero when it is undefined. Added missing
2989 prototypes in posixmodule.c.
2990
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002991- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002992 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002993
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002994- Fix largefile support on older NetBSD systems and OpenBSD by adding
2995 define for TELL64.
2996
2997
2998Tools and other miscellany
2999
3000- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3001
3002- freeze: The modulefinder now works with 2.0 opcodes.
3003
Tim Petersa3a3a032000-11-30 05:22:44 +00003004- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003005 Move hackery of sys.argv until after the Tk instance has been
3006 created, which allows the application-specific Tkinter
3007 initialization to be executed if present; also pass an explicit
3008 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003009
Jeremy Hylton1b618592000-09-26 05:32:36 +00003010
3011What's new in 2.0 beta 1?
3012=========================
3013
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003014Source Incompatibilities
3015------------------------
3016
3017None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3018such as single-argument append(), connect() and bind(), and changes to
3019str(long) and repr(float).
3020
3021
3022Binary Incompatibilities
3023------------------------
3024
3025- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3026with Python 2.0; these extensions will have to be rebuilt for Python
30272.0.
3028
3029- On Windows, attempting to import a third party extension built for
3030Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3031can do about this. Check your PYTHONPATH environment variable!
3032
3033- Python bytecode files (*.pyc and *.pyo) are not compatible between
3034releases.
3035
3036
3037Overview of Changes Since 1.6
3038-----------------------------
3039
3040There are many new modules (including brand new XML support through
3041the xml package, and i18n support through the gettext module); a list
3042of all new modules is included below. Lots of bugs have been fixed.
3043
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003044The process for making major new changes to the language has changed
3045since Python 1.6. Enhancements must now be documented by a Python
3046Enhancement Proposal (PEP) before they can be accepted.
3047
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003048There are several important syntax enhancements, described in more
3049detail below:
3050
3051 - Augmented assignment, e.g. x += 1
3052
3053 - List comprehensions, e.g. [x**2 for x in range(10)]
3054
3055 - Extended import statement, e.g. import Module as Name
3056
3057 - Extended print statement, e.g. print >> file, "Hello"
3058
3059Other important changes:
3060
3061 - Optional collection of cyclical garbage
3062
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003063Python Enhancement Proposal (PEP)
3064---------------------------------
3065
3066PEP stands for Python Enhancement Proposal. A PEP is a design
3067document providing information to the Python community, or describing
3068a new feature for Python. The PEP should provide a concise technical
3069specification of the feature and a rationale for the feature.
3070
3071We intend PEPs to be the primary mechanisms for proposing new
3072features, for collecting community input on an issue, and for
3073documenting the design decisions that have gone into Python. The PEP
3074author is responsible for building consensus within the community and
3075documenting dissenting opinions.
3076
3077The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003078
3079Augmented Assignment
3080--------------------
3081
3082This must have been the most-requested feature of the past years!
3083Eleven new assignment operators were added:
3084
Guido van Rossume905e952000-09-05 12:42:46 +00003085 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003086
3087For example,
3088
3089 A += B
3090
3091is similar to
3092
3093 A = A + B
3094
3095except that A is evaluated only once (relevant when A is something
3096like dict[index].attr).
3097
3098However, if A is a mutable object, A may be modified in place. Thus,
3099if A is a number or a string, A += B has the same effect as A = A+B
3100(except A is only evaluated once); but if a is a list, A += B has the
3101same effect as A.extend(B)!
3102
3103Classes and built-in object types can override the new operators in
3104order to implement the in-place behavior; the not-in-place behavior is
3105used automatically as a fallback when an object doesn't implement the
3106in-place behavior. For classes, the method name is derived from the
3107method name for the corresponding not-in-place operator by inserting
3108an 'i' in front of the name, e.g. __iadd__ implements in-place
3109__add__.
3110
3111Augmented assignment was implemented by Thomas Wouters.
3112
3113
3114List Comprehensions
3115-------------------
3116
3117This is a flexible new notation for lists whose elements are computed
3118from another list (or lists). The simplest form is:
3119
3120 [<expression> for <variable> in <sequence>]
3121
Guido van Rossum56db0952000-09-06 23:34:25 +00003122For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003123This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003124
3125You can also add a condition:
3126
3127 [<expression> for <variable> in <sequence> if <condition>]
3128
3129For example, [w for w in words if w == w.lower()] would yield the list
3130of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003131than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003132
3133You can also have nested for loops and more than one 'if' clause. For
3134example, here's a function that flattens a sequence of sequences::
3135
3136 def flatten(seq):
3137 return [x for subseq in seq for x in subseq]
3138
3139 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3140
3141This prints
3142
3143 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3144
3145List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003146Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003147
3148
3149Extended Import Statement
3150-------------------------
3151
3152Many people have asked for a way to import a module under a different
3153name. This can be accomplished like this:
3154
3155 import foo
3156 bar = foo
3157 del foo
3158
3159but this common idiom gets old quickly. A simple extension of the
3160import statement now allows this to be written as follows:
3161
3162 import foo as bar
3163
3164There's also a variant for 'from ... import':
3165
3166 from foo import bar as spam
3167
3168This also works with packages; e.g. you can write this:
3169
3170 import test.regrtest as regrtest
3171
3172Note that 'as' is not a new keyword -- it is recognized only in this
3173context (this is only possible because the syntax for the import
3174statement doesn't involve expressions).
3175
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003176Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003177
3178
3179Extended Print Statement
3180------------------------
3181
3182Easily the most controversial new feature, this extension to the print
3183statement adds an option to make the output go to a different file
3184than the default sys.stdout.
3185
3186For example, to write an error message to sys.stderr, you can now
3187write:
3188
3189 print >> sys.stderr, "Error: bad dog!"
3190
3191As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003192evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003193
3194 print >> None, "Hello world"
3195
3196is equivalent to
3197
3198 print "Hello world"
3199
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003200Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003201
3202
3203Optional Collection of Cyclical Garbage
3204---------------------------------------
3205
3206Python is now equipped with a garbage collector that can hunt down
3207cyclical references between Python objects. It's no replacement for
3208reference counting; in fact, it depends on the reference counts being
3209correct, and decides that a set of objects belong to a cycle if all
3210their reference counts can be accounted for from their references to
3211each other. This devious scheme was first proposed by Eric Tiedemann,
3212and brought to implementation by Neil Schemenauer.
3213
3214There's a module "gc" that lets you control some parameters of the
3215garbage collection. There's also an option to the configure script
3216that lets you enable or disable the garbage collection. In 2.0b1,
3217it's on by default, so that we (hopefully) can collect decent user
3218experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003219performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003220off by default in the final 2.0 release.
3221
3222
3223Smaller Changes
3224---------------
3225
3226A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3227map(None, seq1, seq2, ...) when the sequences have the same length;
3228i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3229the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003230zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003231
3232sys.version_info is a tuple (major, minor, micro, level, serial).
3233
3234Dictionaries have an odd new method, setdefault(key, default).
3235dict.setdefault(key, default) returns dict[key] if it exists; if not,
3236it sets dict[key] to default and returns that value. Thus:
3237
3238 dict.setdefault(key, []).append(item)
3239
3240does the same work as this common idiom:
3241
3242 if not dict.has_key(key):
3243 dict[key] = []
3244 dict[key].append(item)
3245
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003246There are two new variants of SyntaxError that are raised for
3247indentation-related errors: IndentationError and TabError.
3248
3249Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3250escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003251
3252The limits on the size of expressions and file in Python source code
3253have been raised from 2**16 to 2**32. Previous versions of Python
3254were limited because the maximum argument size the Python VM accepted
3255was 2**16. This limited the size of object constructor expressions,
3256e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3257limit was raised thanks to a patch by Charles Waldman that effectively
3258fixes the problem. It is now much more likely that you will be
3259limited by available memory than by an arbitrary limit in Python.
3260
3261The interpreter's maximum recursion depth can be modified by Python
3262programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3263limit is the maximum number of recursive calls that can be made by
3264Python code. The limit exists to prevent infinite recursion from
3265overflowing the C stack and causing a core dump. The default value is
32661000. The maximum safe value for a particular platform can be found
3267by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003268
3269New Modules and Packages
3270------------------------
3271
3272atexit - for registering functions to be called when Python exits.
3273
3274imputil - Greg Stein's alternative API for writing custom import
3275hooks.
3276
3277pyexpat - an interface to the Expat XML parser, contributed by Paul
3278Prescod.
3279
3280xml - a new package with XML support code organized (so far) in three
3281subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3282would fill a volume. There's a special feature whereby a
3283user-installed package named _xmlplus overrides the standard
3284xmlpackage; this is intended to give the XML SIG a hook to distribute
3285backwards-compatible updates to the standard xml package.
3286
3287webbrowser - a platform-independent API to launch a web browser.
3288
3289
Guido van Rossume905e952000-09-05 12:42:46 +00003290Changed Modules
3291---------------
3292
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003293array -- new methods for array objects: count, extend, index, pop, and
3294remove
3295
3296binascii -- new functions b2a_hex and a2b_hex that convert between
3297binary data and its hex representation
3298
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003299calendar -- Many new functions that support features including control
3300over which day of the week is the first day, returning strings instead
3301of printing them. Also new symbolic constants for days of week,
3302e.g. MONDAY, ..., SUNDAY.
3303
3304cgi -- FieldStorage objects have a getvalue method that works like a
3305dictionary's get method and returns the value attribute of the object.
3306
3307ConfigParser -- The parser object has new methods has_option,
3308remove_section, remove_option, set, and write. They allow the module
3309to be used for writing config files as well as reading them.
3310
3311ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003312optionally support the RFC 959 REST command.
3313
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003314gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003315
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003316httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3317the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003318
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003319locale -- implement getdefaultlocale for Win32 and Macintosh
3320
3321marshal -- no longer dumps core when marshaling deeply nested or
3322recursive data structures
3323
3324os -- new functions isatty, seteuid, setegid, setreuid, setregid
3325
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003326os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3327support under Unix.
3328
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003329os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003330
3331os.path -- fix semantics of os.path.commonprefix
3332
3333smtplib -- support for sending very long messages
3334
3335socket -- new function getfqdn()
3336
3337readline -- new functions to read, write and truncate history files.
3338The readline section of the library reference manual contains an
3339example.
3340
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003341select -- add interface to poll system call
3342
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003343shutil -- new copyfileobj function
3344
3345SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3346HTTP server.
3347
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003348Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003349
3350urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003351e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003352
3353whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003354
3355
3356Obsolete Modules
3357----------------
3358
3359None. However note that 1.6 made a whole slew of modules obsolete:
3360stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3361poly, zmod, strop, util, whatsound.
3362
3363
3364Changed, New, Obsolete Tools
3365----------------------------
3366
Tim Peters8b092332000-09-05 20:15:25 +00003367None.
Guido van Rossume905e952000-09-05 12:42:46 +00003368
3369
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003370C-level Changes
3371---------------
3372
3373Several cleanup jobs were carried out throughout the source code.
3374
3375All C code was converted to ANSI C; we got rid of all uses of the
3376Py_PROTO() macro, which makes the header files a lot more readable.
3377
3378Most of the portability hacks were moved to a new header file,
3379pyport.h; several other new header files were added and some old
3380header files were removed, in an attempt to create a more rational set
3381of header files. (Few of these ever need to be included explicitly;
3382they are all included by Python.h.)
3383
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003384Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003385and Win64, especially for the new Intel Itanium processor. Mick also
3386added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003387
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003388The C APIs to return an object's size have been update to consistently
3389use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3390previous versions, the abstract interfaces used PyXXX_Length and the
3391concrete interfaces used PyXXX_Size. The old names,
3392e.g. PyObject_Length, are still available for backwards compatibility
3393at the API level, but are deprecated.
3394
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003395The PyOS_CheckStack function has been implemented on Windows by
3396Fredrik Lundh. It prevents Python from failing with a stack overflow
3397on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003398
3399The GC changes resulted in creation of two new slots on object,
3400tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003401the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003402
3403The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003404C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003405
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003406PyErr_Format has been updated to automatically calculate the size of
3407the buffer needed to hold the formatted result string. This change
3408prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003409
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003410New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003411
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003412PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3413that are the same as their non-Ex counterparts except they take an
3414extra flag argument that tells them to close the file when done.
3415
3416XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003417
Tim Peters8b092332000-09-05 20:15:25 +00003418
3419Windows Changes
3420---------------
3421
3422New popen2/popen3/peopen4 in os module (see Changed Modules above).
3423
3424os.popen is much more usable on Windows 95 and 98. See Microsoft
3425Knowledge Base article Q150956. The Win9x workaround described there
3426is implemented by the new w9xpopen.exe helper in the root of your
3427Python installation. Note that Python uses this internally; it is not
3428a standalone program.
3429
3430Administrator privileges are no longer required to install Python
3431on Windows NT or Windows 2000. If you have administrator privileges,
3432Python's registry info will be written under HKEY_LOCAL_MACHINE.
3433Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003434under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003435uses of Python, but will prevent some advanced uses from working
3436(for example, running a Python script as an NT service, or possibly
3437from CGI).
3438
3439[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3440installer; instead, it installs the needed Tcl/Tk files directly in the
3441Python directory. If you already have a Tcl/Tk installation, this
3442wastes some disk space (about 4 Megs) but avoids problems with
3443conflicting Tcl/Tk installations, and makes it much easier for Python
3444to ensure that Tcl/Tk can find all its files.
3445
3446[This was new in 1.6] The Windows installer now installs by default in
3447\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3448
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003449
3450Updates to the changes between 1.5.2 and 1.6
3451--------------------------------------------
3452
3453The 1.6 NEWS file can't be changed after the release is done, so here
3454is some late-breaking news:
3455
3456New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3457and changes to getlocale() and setlocale().
3458
3459The new module is now enabled per default.
3460
3461It is not true that the encodings codecs cannot be used for normal
3462strings: the string.encode() (which is also present on 8-bit strings
3463!) allows using them for 8-bit strings too, e.g. to convert files from
3464cp1252 (Windows) to latin-1 or vice-versa.
3465
3466Japanese codecs are available from Tamito KAJIYAMA:
3467http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3468
3469
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003470======================================================================