blob: 2c7646d22f48459f45c2b8420bd55e988f0c3b85 [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
Neal Norwitzd68f5172002-05-29 15:54:55 +00009- A new warning PendingDeprecationWarning was added to provide
10 direction on features which are in the process of being deprecated.
11 The warning will not be printed by default. To see the pending
12 deprecations, use -Walways::PendingDeprecationWarning::
13 as a command line option or warnings.filterwarnings() in code.
14
Guido van Rossumcacfc072002-05-24 19:01:59 +000015- A new type object, 'string', is added. This is a common base type
16 for 'str' and 'unicode', and can be used instead of
17 types.StringTypes, e.g. to test whether something is "a string":
18 isinstance(x, string) is True for Unicode and 8-bit strings. This
19 is an abstract base class and cannot be instantiated directly.
20
Fred Draked0ba6362002-05-02 21:28:26 +000021- Deprecated features of xrange objects have been removed as
22 promised. The start, stop, and step attributes and the tolist()
23 method no longer exist. xrange repetition and slicing have been
24 removed.
25
Guido van Rossum7dab2422002-04-26 19:40:56 +000026- New builtin function enumerate(x), from PEP 279. Example:
27 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
28 The argument can be an arbitrary iterable object.
29
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000030- The assert statement no longer tests __debug__ at runtime. This means
31 that assert statements cannot be disabled by assigning a false value
32 to __debug__.
33
Walter Dörwald068325e2002-04-15 13:36:47 +000034- A method zfill() was added to str and unicode, that fills a numeric
35 string to the left with zeros. For example,
36 "+123".zfill(6) -> "+00123".
37
Guido van Rossum862fe3c2002-04-15 12:36:47 +000038- Complex numbers supported divmod() and the // and % operators, but
39 these make no sense. Since this was documented, they're being
40 deprecated now.
41
Guido van Rossum26dd8302002-04-26 20:11:29 +000042- String and unicode methods lstrip(), rstrip() and strip() now take
43 an optional argument that specifies the characters to strip. For
44 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000045
Guido van Rossumc69343b2002-04-12 19:22:48 +000046- Added a new dict method pop(key). This removes and returns the
47 value corresponding to key. [SF patch #539949]
48
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000049- Changed new-style class instantiation so that when C's __new__
50 method returns something that's not a C instance, its __init__ is
51 not called. [SF bug #537450]
52
Guido van Rossum181e41a2002-04-06 00:23:25 +000053- Fixed super() to work correctly with class methods. [SF bug #535444]
54
Guido van Rossum47834462002-04-04 15:21:33 +000055- A new built-in type, bool, has been added, as well as built-in
56 names for its two values, True and False. Comparisons and sundry
57 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000058 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000059 is backward compatible.
60
Guido van Rossum95b62a62002-03-29 01:07:24 +000061- Fixed two bugs reported as SF #535905: under certain conditions,
62 deallocating a deeply nested structure could cause a segfault in the
63 garbage collector, due to interaction with the "trashcan" code;
64 access to the current frame during destruction of a local variable
65 could access a pointer to freed memory.
66
Neil Schemenauer9d50d132002-03-22 17:06:59 +000067- The optional object allocator has been enabled by default.
68
Guido van Rossum8c842552002-03-14 23:05:54 +000069- If you try to pickle an instance of a class that has __slots__ but
70 doesn't define or override __getstate__, a TypeError is now raised.
71 This is done by adding a bozo __getstate__ to the class that always
72 raises TypeError. (Before, this would appear to be pickled, but the
73 state of the slots would be lost.)
74
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000075- PyErr_Display will provide file and line information for all exceptions
76 that have an attribute print_file_and_line, not just SyntaxErrors.
77
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000078- The UTF-8 codec will now encode and decode Unicode surrogates
79 correctly and without raising exceptions for unpaired ones.
80
Neal Norwitz649b7592002-01-01 19:07:13 +000081- file.xreadlines() now raises a ValueError if the file is closed:
82 Previously, an xreadlines object was returned which would raise
83 a ValueError when the xreadlines.next() method was called.
84
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000085- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +000086 An exception will now be raised if more than one argument is used.
87
Tim Petersaf8446f2001-12-21 21:36:50 +000088Extension modules
89
Tim Peters81b92512002-04-29 01:37:32 +000090- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +000091 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +000092 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +000093
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000094- posix.killpg and posix.mknod have been added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +000095
Martin v. Löwis2e64c342002-03-27 18:49:02 +000096- The locale module now exposes the C library's gettext interface.
97
Tim Petersfbf74f22002-03-14 19:06:01 +000098- A security hole ("double free") was found in zlib-1.1.3, a popular
99 third party compression library used by some Python modules. The
100 hole was quickly plugged in zlib-1.1.4, and the Windows build of
101 Python now ships with zlib-1.1.4.
102
Martin v. Löwis688357e2002-04-08 21:28:20 +0000103- pwd, grp, and resource return enhanced tuples now, with symbolic
104 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000105
Martin v. Löwis99866332002-03-01 10:27:01 +0000106- array.array is now a type object. A new format character
107 'u' indicates Py_UNICODE arrays. For those, .tounicode and
108 .fromunicode methods are available. Arrays now support __iadd__
109 and __imul__.
110
Neal Norwitze790eae2002-01-01 21:14:12 +0000111- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000112 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
113 is called.
114
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000115- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
116 been added where available.
117
Tim Petersaf8446f2001-12-21 21:36:50 +0000118Library
119
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000120- added degree/radian conversion functions to the math module.
121
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000122- ftplib.retrlines() now tests for callback is None rather than testing
123 for False. Was causing an error when given a callback object which
124 was callable but also returned len() as zero. The change may
125 create new breakage if the caller relied on the undocumented behavior
126 and called with callback set to [] or some other False value not
127 identical to None.
128
Tim Peters46c04e12002-05-05 20:40:00 +0000129- random.gauss() uses a piece of hidden state used by nothing else,
130 and the .seed() and .whseed() methods failed to reset it. In other
131 words, setting the seed didn't completely determine the sequence of
132 results produced by random.gauss(). It does now. Programs repeatedly
133 mixing calls to a seed method with calls to gauss() may see different
134 results now.
135
Fred Drake7f781c92002-05-01 20:33:53 +0000136- The pickle.Pickler class grew a clear_memo() method to mimic that
137 provided by cPickle.Pickler.
138
Tim Peters81b92512002-04-29 01:37:32 +0000139- difflib's SequenceMatcher class now does a dynamic analysis of
140 which elements are so frequent as to constitute noise. For
141 comparing files as sequences of lines, this generally works better
142 than the IS_LINE_JUNK function, and function ndiff's linejunk
143 argument defaults to None now as a result. A happy benefit is
144 that SequenceMatcher may run much faster now when applied
145 to large files with many duplicate lines (for example, C program
146 text with lots of repeated "}" and "return NULL;" lines).
147
Guido van Rossum256705b2002-04-23 13:29:43 +0000148- New Text.dump() method in Tkinter module.
149
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000150- New distutils commands for building packagers were added to
151 support pkgtool on Solaris and swinstall on HP-UX.
152
153- distutils now has a new abstract binary packager base class
154 command/bdist_packager, which simplifies writing packagers.
155 This will hopefully provide the missing bits to encourage
156 people to submit more packagers, e.g. for Debian, FreeBSD
157 and other systems.
158
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000159- The UTF-16, -LE and -BE now raise a NotImplementedError
160 for all calls to .readline(). Previously, they used to just
161 produce garbage or fail with an encoding error -- UTF-16 is
162 a 2-byte encoding and the C lib's line reading APIs don't
163 work well with these.
164
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000165- compileall now supports quiet operation.
166
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000167- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000168 connections.
169
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000170- socket module: the SSL support was broken out of the main
171 _socket module C helper and placed into a new _ssl helper
172 which now gets imported by socket.py if available and working.
173
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000174- encodings package: added aliases for all supported IANA character
175 sets
176
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000177- ftplib: to safeguard the user's privacy, anonymous login will use
178 "anonymous@" as default password, rather than the real user and host
179 name.
180
Fred Drake36736122002-01-10 13:50:31 +0000181- webbrowser: tightened up the command passed to os.system() so that
182 arbitrary shell code can't be executed because a bogus URL was
183 passed in.
184
Tim Peters11bd9942002-02-01 00:52:29 +0000185- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000186 gettext.find an optional all argument. Translations will now fallback
187 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000188
Martin v. Löwis9668b932002-01-12 11:27:42 +0000189- distutils bdist commands now offer a --skip-build option.
190
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000191- warnings.warn now accepts a Warning instance as first argument.
192
Fred Drakefed7e852002-04-04 19:36:15 +0000193- The xml.sax.expatreader.ExpatParser class will no longer create
194 circular references by using itself as the locator that gets passed
195 to the content handler implementation. [SF bug #535474]
196
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000197- The email.Parser.Parser class now properly parses strings regardless
198 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
199 or CRLF). Also, the Header class's constructor default arguments
200 has changed slightly so that an explicit maxlinelen value is always
201 honored.
202
Tim Petersaf8446f2001-12-21 21:36:50 +0000203Tools/Demos
204
Marc-André Lemburg46260092002-04-04 16:17:11 +0000205- freeze.py now produces binaries which can import shared modules,
206 unlike before when this failed due to missing symbol exports in
207 the generated binary.
208
Tim Petersaf8446f2001-12-21 21:36:50 +0000209Build
210
Tim Peters639295f2002-04-21 07:30:30 +0000211- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
212 say how or when to configure it, or how to turn it off.
213
Martin v. Löwis1142de32002-03-29 16:28:31 +0000214- On Unix, a shared libpython2.3.so can be created with --enable-shared.
215
Tim Peters8deda702002-03-30 10:06:07 +0000216- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
217 preprocessor symbols were eliminated. The internal decisions they
218 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000219
Fred Drake7d28b732002-05-02 21:17:00 +0000220- The tools used to build the documentation now work under Cygwin as
221 well as Unix.
222
Tim Petersaf8446f2001-12-21 21:36:50 +0000223C API
224
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000225- Added new macro PySequence_ITEM(o, i) that directly calls
226 sq_item without rechecking that o is a sequence and without
227 adjusting for negative indices.
228
Fred Draked0ba6362002-05-02 21:28:26 +0000229- PyRange_New() now raises ValueError if the fourth argument is not 1.
230 This is part of the removal of deprecated features of the xrange
231 object.
232
Guido van Rossum517c7d42002-04-26 02:49:14 +0000233- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
234 coercion if both arguments have the same type but this type has the
235 CHECKTYPES flag set. This is to better support proxies.
236
Neil Schemenauer9344b142002-04-12 23:00:08 +0000237- The type of tp_free has been changed from "void (*)(PyObject *)" to
238 "void (*)(void *)".
239
240- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
241
Guido van Rossum0986d822002-04-08 01:38:42 +0000242- A type can now inherit its metatype from its base type. Previously,
243 when PyType_Ready() was called, if ob_type was found to be NULL, it
244 was always set to &PyType_Type; now it is set to base->ob_type,
245 where base is tp_base, defaulting to &PyObject_Type.
246
247- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
248
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000249- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000250
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000251- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000252 without going through the buffer API.
253
Martin v. Löwis7198a522002-01-01 19:59:11 +0000254- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
255
Tim Peters10a3bb52001-12-25 19:07:38 +0000256- An old #define of ANY as void has been removed from pyport.h. This
257 hasn't been used since Python's pre-ANSI days, and the #define has
258 been marked as obsolete since then. SF bug 495548 says it created
259 conflicts with other packages, so keeping it around wasn't harmless.
260
Tim Petersaf8446f2001-12-21 21:36:50 +0000261- Because Python's magic number scheme broke on January 1st, we decided
262 to stop Python development. Thanks for all the fish!
263
Tim Petersfb05db22002-03-11 00:24:00 +0000264- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000265 scheme to a new one. See Python/import.c for details.
266
Tim Petersaf8446f2001-12-21 21:36:50 +0000267New platforms
268
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000269- GNU/Hurd is now supported.
270
Tim Petersaf8446f2001-12-21 21:36:50 +0000271Tests
272
273Windows
274
Tim Peters08e72952002-04-16 20:48:01 +0000275- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
276 of that has been fixed in the installer (disabled Wise's "delete in-
277 use files" uninstall option).
278
Guido van Rossum181e41a2002-04-06 00:23:25 +0000279- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
280
Tim Peters33187922002-04-04 20:02:04 +0000281- The installer now installs Start menu shortcuts under (the local
282 equivalent of) "All Users" when doing an Admin install.
283
Tim Petersfb05db22002-03-11 00:24:00 +0000284- file.truncate([newsize]) now works on Windows for all newsize values.
285 It used to fail if newsize didn't fit in 32 bits, reflecting a
286 limitation of MS _chsize (which is no longer used).
287
Tim Petersab034fa2002-02-01 11:27:43 +0000288- os.waitpid() is now implemented for Windows, and can be used to block
289 until a specified process exits. This is similar to, but not exactly
290 the same as, os.waitpid() on POSIX systems. If you're waiting for
291 a specific process whose pid was obtained from one of the spawn()
292 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000293 See the docs for details. The docs were changed to clarify that
294 spawn functions return, and waitpid requires, a process handle on
295 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000296
Tim Peters11bd9942002-02-01 00:52:29 +0000297- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000298 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000299 to a nasty problem: before 2.3, if you got a temp file on Windows, it
300 got wrapped in an object whose close() method first closed the
301 underlying file, then deleted the file. This usually worked fine.
302 However, the spawn family of functions on Windows create (at a low C
303 level) the same set of open files in the spawned process Q as were
304 open in the spawning process P. If a temp file f was among them, then
305 doing f.close() in P first closed P's C-level file handle on f, but Q's
306 C-level file handle on f remained open, so the attempt in P to delete f
307 blew up with a "Permission denied" error (Windows doesn't allow
308 deleting open files). This was surprising, subtle, and difficult to
309 work around.
310
311- The os module now exports all the symbolic constants usable with the
312 low-level os.open() on Windows: the new constants in 2.3 are
313 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
314 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
315 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
316 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
317 (so specify both if you want both; note that neither is useful unless
318 specified with O_CREAT too).
319
Tim Petersaf8446f2001-12-21 21:36:50 +0000320Mac
321
322
Tim Peters909c0912001-12-14 23:16:18 +0000323What's New in Python 2.2 final?
324Release date: 21-Dec-2001
325===============================
326
327Type/class unification and new-style classes
328
Barry Warsaw52acb492001-12-21 20:04:22 +0000329- pickle.py, cPickle: allow pickling instances of new-style classes
330 with a custom metaclass.
331
Tim Peters909c0912001-12-14 23:16:18 +0000332Core and builtins
333
Barry Warsaw52acb492001-12-21 20:04:22 +0000334- weakref proxy object: when comparing, unwrap both arguments if both
335 are proxies.
336
Tim Peters909c0912001-12-14 23:16:18 +0000337Extension modules
338
Barry Warsaw52acb492001-12-21 20:04:22 +0000339- binascii.b2a_base64(): fix a potential buffer overrun when encoding
340 very short strings.
341
342- cPickle: the obscure "fast" mode was suspected of causing stack
343 overflows on the Mac. Hopefully fixed this by setting the recursion
344 limit much smaller. If the limit is too low (it only affects
345 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
346 when compiling cPickle.c (or in pyconfig.h).
347
Tim Peters909c0912001-12-14 23:16:18 +0000348Library
349
Barry Warsaw52acb492001-12-21 20:04:22 +0000350- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
351 close or delete time).
352
353- rfc822.py: fixed a bug where the address '<>' was converted to None
354 instead of an empty string (also fixes the email.Utils module).
355
356- xmlrpclib.py: version 1.0.0; uses precision for doubles.
357
358- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000359 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000360
Tim Peters909c0912001-12-14 23:16:18 +0000361Tools/Demos
362
363Build
364
365C API
366
367New platforms
368
369Tests
370
371Windows
372
Barry Warsaw52acb492001-12-21 20:04:22 +0000373- distutils package: fixed broken Windows installers (bdist_wininst).
374
375- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
376 instances are deleted at process exit time.
377
378- socket.py: prevent mysterious warnings when socket instances are
379 deleted at process exit time.
380
381- posixmodule.c: fix a Windows crash with stat() of a filename ending
382 in backslash.
383
Tim Peters909c0912001-12-14 23:16:18 +0000384Mac
385
Barry Warsaw52acb492001-12-21 20:04:22 +0000386- The Carbon toolbox modules have been upgraded to Universal Headers
387 3.4, and experimental CoreGraphics and CarbonEvents modules have
388 been added. All only for framework-enabled MacOSX.
389
Tim Peters909c0912001-12-14 23:16:18 +0000390
Tim Peters6272dfd2001-12-13 19:34:00 +0000391What's New in Python 2.2c1?
392Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000393===========================
394
395Type/class unification and new-style classes
396
Barry Warsaw06557452001-12-14 20:47:12 +0000397- Guido's tutorial introduction to the new type/class features has
398 been extensively updated. See
399
400 http://www.python.org/2.2/descrintro.html
401
402 That remains the primary documentation in this area.
403
Guido van Rossum33bab012001-12-05 22:45:48 +0000404- Fixed a leak: instance variables declared with __slots__ were never
405 deleted!
406
Guido van Rossum4b800852001-12-03 00:54:52 +0000407- The "delete attribute" method of descriptor objects is called
408 __delete__, not __del__. In previous releases, it was mistakenly
409 called __del__, which created an unfortunate overloading condition
410 with finalizers. (The "get attribute" and "set attribute" methods
411 are still called __get__ and __set__, respectively.)
412
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000413- Some subtle issues with the super built-in were fixed:
414
415 (a) When super itself is subclassed, its __get__ method would still
416 return an instance of the base class (i.e., of super).
417
418 (b) super(C, C()).__class__ would return C rather than super. This
419 is confusing. To fix this, I decided to change the semantics of
420 super so that it only applies to code attributes, not to data
421 attributes. After all, overriding data attributes is not
422 supported anyway.
423
424 (c) The __get__ method didn't check whether the argument was an
425 instance of the type used in creation of the super instance.
426
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000427- Previously, hash() of an instance of a subclass of a mutable type
428 (list or dictionary) would return some value, rather than raising
429 TypeError. This has been fixed. Also, directly calling
430 dict.__hash__ and list.__hash__ now raises the same TypeError
431 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000432
Guido van Rossumd331cb52001-12-05 19:46:42 +0000433- New-style objects now support deleting their __dict__. This is for
434 all intents and purposes equivalent to assigning a brand new empty
435 dictionary, but saves space if the object is not used further.
436
Tim Petersb3c9af12001-11-17 00:21:57 +0000437Core and builtins
438
Tim Peters3caca232001-12-06 06:23:26 +0000439- -Qnew now works as documented in PEP 238: when -Qnew is passed on
440 the command line, all occurrences of "/" use true division instead
441 of classic division. See the PEP for details. Note that "all"
442 means all instances in library and 3rd-party modules, as well as in
443 your own code. As the PEP says, -Qnew is intended for use only in
444 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000445 Note that test_coercion.py in the standard Python test suite fails
446 under -Qnew; this is expected, and won't be repaired until true
447 division becomes the default (in the meantime, test_coercion is
448 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000449
Fred Drake6c01e252001-12-14 17:08:12 +0000450- complex() now only allows the first argument to be a string
451 argument, and raises TypeError if either the second arg is a string
452 or if the second arg is specified when the first is a string.
453
Tim Petersb3c9af12001-11-17 00:21:57 +0000454Extension modules
455
Martin v. Löwis560da622001-11-24 09:24:51 +0000456- gc.get_referents was renamed to gc.get_referrers.
457
Tim Petersb3c9af12001-11-17 00:21:57 +0000458Library
459
Tim Peters25059d32001-12-07 20:35:43 +0000460- Functions in the os.spawn() family now release the global interpreter
461 lock around calling the platform spawn. They should always have done
462 this, but did not before 2.2c1. Multithreaded programs calling
463 an os.spawn function with P_WAIT will no longer block all Python threads
464 until the spawned program completes. It's possible that some programs
465 relies on blocking, although more likely by accident than by design.
466
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000467- webbrowser defaults to netscape.exe on OS/2 now.
468
Martin v. Löwis652e1912001-11-25 14:50:56 +0000469- Tix.ResizeHandle exposes detach_widget, hide, and show.
470
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000471- The charset alias windows_1252 has been added.
472
Barry Warsaw06557452001-12-14 20:47:12 +0000473- types.StringTypes is a tuple containing the defined string types;
474 usually this will be (str, unicode), but if Python was compiled
475 without Unicode support it will be just (str,).
476
477- The pulldom and minidom modules were synchronized to PyXML.
478
Tim Petersb3c9af12001-11-17 00:21:57 +0000479Tools/Demos
480
Barry Warsaw06557452001-12-14 20:47:12 +0000481- A new script called Tools/scripts/google.py was added, which fires
482 off a search on Google.
483
Tim Petersb3c9af12001-11-17 00:21:57 +0000484Build
485
Barry Warsaw06557452001-12-14 20:47:12 +0000486- Note that release builds of Python should arrange to define the
487 preprocessor symbol NDEBUG on the command line (or equivalent).
488 In the 2.2 pre-release series we tried to define this by magic in
489 Python.h instead, but it proved to cause problems for extension
490 authors. The Unix, Windows and Mac builds now all define NDEBUG in
491 release builds via cmdline (or equivalent) instead. Ports to
492 other platforms should do likewise.
493
Jack Jansen1999ef42001-12-06 21:47:20 +0000494- It is no longer necessary to use --with-suffix when building on a
495 case-insensitive file system (such as Mac OS X HFS+). In the build
496 directory an extension is used, but not in the installed python.
497
Tim Petersb3c9af12001-11-17 00:21:57 +0000498C API
499
Tim Petersf582b822001-12-11 18:51:08 +0000500- New function PyDict_MergeFromSeq2() exposes the builtin dict
501 constructor's logic for updating a dictionary from an iterable object
502 producing key-value pairs.
503
Tim Peterscffed4b2001-11-29 03:26:37 +0000504- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000505 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000506 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
507 dump core in some bad cases. This has been repaired. As a result,
508 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
509 previously went unchallenged.
510
Tim Petersb3c9af12001-11-17 00:21:57 +0000511New platforms
512
513Tests
514
515Windows
516
517Mac
518
Jack Jansenffa260f2001-12-06 21:14:00 +0000519- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
520 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000521
Barry Warsaw06557452001-12-14 20:47:12 +0000522- Changed logic for finding python home in Mac OS X framework Pythons.
523 Now sys.executable points to the executable again, in stead of to
524 the shared library. The latter is used only for locating the python
525 home.
526
527
Tim Peters84362bc2001-10-19 17:55:30 +0000528What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000529Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000530===========================
531
532Type/class unification and new-style classes
533
Guido van Rossum3d27df02001-11-15 20:27:54 +0000534- Multiple inheritance mixing new-style and classic classes in the
535 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000536
537 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000538 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000539
540 The MRO (method resolution order) for each base class is respected
541 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000542 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000543 This needs to be documented.
544
Tim Petersa427a2b2001-10-29 22:25:45 +0000545- The new builtin dictionary() constructor, and dictionary type, have
546 been renamed to dict. This reflects a decade of common usage.
547
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000548- dict() now accepts an iterable object producing 2-sequences. For
549 example, dict(d.items()) == d for any dictionary d. The argument,
550 and the elements of the argument, can be any iterable objects.
551
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000552- New-style classes can now have a __del__ method, which is called
553 when the instance is deleted (just like for classic classes).
554
Guido van Rossum12d955c2001-10-26 14:56:06 +0000555- Assignment to object.__dict__ is now possible, for objects that are
556 instances of new-style classes that have a __dict__ (unless the base
557 class forbids it).
558
Guido van Rossumc8e56452001-10-22 00:43:43 +0000559- Methods of built-in types now properly check for keyword arguments
560 (formerly these were silently ignored). The only built-in methods
561 that take keyword arguments are __call__, __init__ and __new__.
562
Guido van Rossum86443212001-10-27 22:28:54 +0000563- The socket function has been converted to a type; see below.
564
Tim Peters84362bc2001-10-19 17:55:30 +0000565Core and builtins
566
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000567- Assignment to __debug__ raises SyntaxError at compile-time. This
568 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000569 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000570
Guido van Rossum12d955c2001-10-26 14:56:06 +0000571- Clarified the error messages for unsupported operands to an operator
572 (like 1 + '').
573
Tim Peters84362bc2001-10-19 17:55:30 +0000574Extension modules
575
Tim Peters5ebfd362001-11-13 23:11:19 +0000576- mmap has a new keyword argument, "access", allowing a uniform way for
577 both Windows and Unix users to create read-only, write-through and
578 copy-on-write memory mappings. This was previously possible only on
579 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000580 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000581 platforms. Thanks to Jay T Miller for repairing this!
582
Tim Peters169ded02001-11-03 19:57:21 +0000583- By default, the gc.garbage list now contains only those instances in
584 unreachable cycles that have __del__ methods; in 2.1 it contained all
585 instances in unreachable cycles. "Instances" here has been generalized
586 to include instances of both new-style and old-style classes.
587
Guido van Rossum12d955c2001-10-26 14:56:06 +0000588- The socket module defines a new method for socket objects,
589 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000590 send() until all data has been sent. Also, the socket function has
591 been converted to a subclassable type, like list and tuple (etc.)
592 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000593
594- Various bugfixes to the curses module. There is now a test suite
595 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000596
Guido van Rossum692adf12001-10-30 03:03:03 +0000597- binascii.b2a_base64 no longer places an arbitrary restriction of 57
598 bytes on its input.
599
Tim Peters84362bc2001-10-19 17:55:30 +0000600Library
601
Tim Peters5ebfd362001-11-13 23:11:19 +0000602- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000603 convenience function.
604
Tim Peters75335872001-11-03 19:35:43 +0000605- Symbolic group names in regular expressions must be unique. For
606 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
607 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000608 Python 2.2 detects this error at regexp compilation time;
609 previously, the error went undetected, and results were
610 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
611 pattern.subn() methods have been rewritten in C. Also, an
612 experimental function/method finditer() has been added, which works
613 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000614
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000615- Tix exposes more commands through the classes DirSelectBox,
616 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
617 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
618 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
619
Tim Peters98791af2001-10-23 01:59:54 +0000620- Traceback objects are now scanned by cyclic garbage collection, so
621 cycles created by casual use of sys.exc_info() no longer cause
622 permanent memory leaks (provided garbage collection is enabled).
623
Guido van Rossum49192142001-10-24 20:51:44 +0000624- os.extsep -- a new variable needed by the RISCOS support. It is the
625 separator used by extensions, and is '.' on all platforms except
626 RISCOS, where it is '/'. There is no need to use this variable
627 unless you have a masochistic desire to port your code to RISCOS.
628
Barry Warsaw012852b2001-11-16 16:17:27 +0000629- mimetypes.py has optional support for non-standard, but commonly
630 found types. guess_type() and guess_extension() now accept an
631 optional `strict' flag, defaulting to true, which controls whether
632 recognize non-standard types or not. A few non-standard types we
633 know about have been added. Also, when run as a script, there are
634 new -l and -e options.
635
636- statcache is now deprecated.
637
638- email.Utils.formatdate() now produces the preferred RFC 2822 style
639 dates with numeric timezones (it used to produce obsolete dates
640 hard coded to "GMT" timezone). An optional `localtime' flag is
641 added to produce dates in the local timezone, with daylight savings
642 time properly taken into account.
643
644- In pickle and cPickle, instead of masking errors in load() by
645 transforming them into SystemError, we let the original exception
646 propagate out. Also, implement support for __safe_for_unpickling__
647 in pickle, as it already was supported in cPickle.
648
Tim Peters84362bc2001-10-19 17:55:30 +0000649Tools/Demos
650
651Build
652
Barry Warsaw012852b2001-11-16 16:17:27 +0000653- The dbm module is built using libdb1 if available. The bsddb module
654 is built with libdb3 if available.
655
656- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
657
Tim Peters84362bc2001-10-19 17:55:30 +0000658C API
659
Tim Peters1fc240e2001-10-26 05:06:50 +0000660- New function PySequence_Fast_GET_SIZE() returns the size of a non-
661 NULL result from PySequence_Fast(), more quickly than calling
662 PySequence_Size().
663
Barry Warsaw012852b2001-11-16 16:17:27 +0000664- New argument unpacking function PyArg_UnpackTuple() added.
665
666- New functions PyObject_CallFunctionObjArgs() and
667 PyObject_CallMethodObjArgs() have been added to make it more
668 convenient and efficient to call functions and methods from C.
669
670- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
671 possible that this will propagate errors it didn't before.
672
673- New function PyObject_CheckReadBuffer(), which returns true if its
674 argument supports the single-segment readable buffer interface.
675
Tim Peters84362bc2001-10-19 17:55:30 +0000676New platforms
677
Guido van Rossum86443212001-10-27 22:28:54 +0000678- We've finally confirmed that this release builds on HP-UX 11.00,
679 *with* threads, and passes the test suite.
680
Tim Peters7a33d8b2001-11-05 02:51:07 +0000681- Thanks to a series of patches from Michael Muller, Python may build
682 again under OS/2 Visual Age C++.
683
Guido van Rossum49192142001-10-24 20:51:44 +0000684- Updated RISCOS port by Dietmar Schwertberger.
685
Tim Peters84362bc2001-10-19 17:55:30 +0000686Tests
687
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000688- Added a test script for the curses module. It isn't run automatically;
689 regrtest.py must be run with '-u curses' to enable it.
690
Tim Peters84362bc2001-10-19 17:55:30 +0000691Windows
692
Barry Warsaw012852b2001-11-16 16:17:27 +0000693Mac
694
695- PythonScript has been moved to unsupported and is slated to be
696 removed completely in the next release.
697
698- It should now be possible to build applets that work on both OS9 and
699 OSX.
700
701- The core is now linked with CoreServices not Carbon; as a side
702 result, default 8bit encoding on OSX is now ASCII.
703
704- Python should now build on OSX 10.1.1
705
Tim Peters84362bc2001-10-19 17:55:30 +0000706
Tim Petersabf925f2001-09-28 21:53:42 +0000707What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000708Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000709===========================
710
711Type/class unification and new-style classes
712
Guido van Rossum687ae002001-10-15 22:03:32 +0000713- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000714 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000715 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000716 remains: the __dict__ of a new-style class is a read-only proxy; you
717 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000718 __defined__ attribute of new-style types no longer exists, for lack
719 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000720 future a __cache__ may be resurrected with a similar function, if I
721 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000722
Tim Peters1c9ca872001-10-04 06:43:12 +0000723- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
724 always returned None, even when there was a class docstring).
725
726- doctest now finds and runs docstrings attached to new-style classes,
727 class methods, static methods, and properties.
728
Guido van Rossum9074ef62001-10-16 21:34:49 +0000729Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000730
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000731- A very subtle syntactical pitfall in list comprehensions was fixed.
732 For example: [a+b for a in 'abc', for b in 'def']. The comma in
733 this example is a mistake. Previously, this would silently let 'a'
734 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
735 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
736 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
737 Note that [a for a in <singleton>] is a convoluted way to say
738 [<singleton>] anyway, so it's not like any expressiveness is lost.
739
Guido van Rossum9074ef62001-10-16 21:34:49 +0000740- getattr(obj, name, default) now only catches AttributeError, as
741 documented, rather than returning the default value for all
742 exceptions (which could mask bugs in a __getattr__ hook, for
743 example).
744
Fred Drakecb7a6b52001-10-22 18:41:51 +0000745- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000746 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000747 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000748 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000749
Guido van Rossum1c486092001-10-19 02:05:35 +0000750- unicode(obj) now behaves more like str(obj), accepting arbitrary
751 objects, and calling a __unicode__ method if it exists.
752 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000753 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000754
Barry Warsawf6fb1712001-10-19 05:35:40 +0000755- isinstance() now allows any object as the first argument and a
756 class, a type or something with a __bases__ tuple attribute for the
757 second argument. The second argument may also be a tuple of a
758 class, type, or something with __bases__, in which case isinstance()
759 will return true if the first argument is an instance of any of the
760 things contained in the second argument tuple. E.g.
761
762 isinstance(x, (A, B))
763
764 returns true if x is an instance of A or B.
765
Guido van Rossum9074ef62001-10-16 21:34:49 +0000766Extension modules
767
768- thread.start_new_thread() now returns the thread ID (previously None).
769
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000770- binascii has now two quopri support functions, a2b_qp and b2a_qp.
771
Guido van Rossumc524d952001-10-19 01:31:59 +0000772- readline now supports setting the startup_hook and the
773 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000774
Guido van Rossumc524d952001-10-19 01:31:59 +0000775- os and posix supports chroot(), setgroups() and unsetenv() where
776 available. The stat(), fstat(), statvfs() and fstatvfs() functions
777 now return "pseudo-sequences" -- the various fields can now be
778 accessed as attributes (e.g. os.stat("/").st_mtime) but for
779 backwards compatibility they also behave as a fixed-length sequence.
780 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000781 attributes.
782
783- time: localtime(), gmtime() and strptime() now return a
784 pseudo-sequence similar to the os.stat() return value, with
785 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000786
Guido van Rossum9074ef62001-10-16 21:34:49 +0000787- Decompression objects in the zlib module now accept an optional
788 second parameter to decompress() that specifies the maximum amount
789 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000790
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000791- optional SSL support in the socket module now exports OpenSSL
792 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
793 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000794 automatically seed its PRNG. Also, the keyfile and certfile
795 arguments to socket.ssl() are now optional.
796
797- posixmodule (and by extension, the os module on POSIX platforms) now
798 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000799
Guido van Rossum9074ef62001-10-16 21:34:49 +0000800Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000801
Tim Peters7402f792001-10-02 03:53:41 +0000802- doctest now excludes functions and classes not defined by the module
803 being tested, thanks to Tim Hochberg.
804
Fred Drakecb7a6b52001-10-22 18:41:51 +0000805- HotShot, a new profiler implemented using a C-based callback, has
806 been added. This substantially reduces the overhead of profiling,
807 but it is still quite preliminary. Support modules and
808 documentation will be added in upcoming releases (before 2.2 final).
809
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000810- profile now produces correct output in situations where an exception
811 raised in Python is cleared by C code (e.g. hasattr()). This used
812 to cause wrong output, including spurious claims of recursive
813 functions and attribution of time spent to the wrong function.
814
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000815 The code and documentation for the derived OldProfile and HotProfile
816 profiling classes was removed. The code hasn't worked for years (if
817 you tried to use them, they raised exceptions). OldProfile
818 intended to reproduce the behavior of the profiler Python used more
819 than 7 years ago, and isn't interesting anymore. HotProfile intended
820 to provide a faster profiler (but producing less information), and
821 that's a worthy goal we intend to meet via a different approach (but
822 without losing information).
823
Tim Peterscce092d2001-10-09 05:31:56 +0000824- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000825 a much better system-specific calibration constant. The constant can
826 now be specified in an instance constructor, or as a Profile class or
827 instance variable, instead of by editing profile.py's source code.
828 Calibration must still be done manually (see the docs for the profile
829 module).
830
831 Note that Profile.calibrate() must be overriden by subclasses.
832 Improving the accuracy required exploiting detailed knowledge of
833 profiler internals; the earlier method abstracted away the details
834 and measured a simplified model instead, but consequently computed
835 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000836
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000837- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000838 which indicates whether output is intended for the header 'Q'
839 encoding.
840
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000841- The SocketServer.ThreadingMixIn class now closes the request after
842 finish_request() returns. (Not when it errors out though.)
843
Barry Warsawf6fb1712001-10-19 05:35:40 +0000844- The nntplib module's NNTP.body() method has grown a `file' argument
845 to allow saving the message body to a file.
846
847- The email package has added a class email.Parser.HeaderParser which
848 only parses headers and does not recurse into the message's body.
849 Also, the module/class MIMEAudio has been added for representing
850 audio data (contributed by Anthony Baxter).
851
852- ftplib should be able to handle files > 2GB.
853
854- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
855 ON, and OFF.
856
Fred Drakecb7a6b52001-10-22 18:41:51 +0000857- xml.dom.minidom NodeList objects now support the length attribute
858 and item() method as required by the DOM specifications.
859
Guido van Rossumed554f62001-10-02 23:15:37 +0000860Tools/Demos
861
862- Demo/dns was removed. It no longer serves any purpose; a package
863 derived from it is now maintained by Anthony Baxter, see
864 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000865
Barry Warsawf6fb1712001-10-19 05:35:40 +0000866- The freeze tool has been made more robust, and two new options have
867 been added: -X and -E.
868
Tim Petersabf925f2001-09-28 21:53:42 +0000869Build
870
Barry Warsawf6fb1712001-10-19 05:35:40 +0000871- configure will use CXX in LINKCC if CXX is used to build main() and
872 the system requires to link a C++ main using the C++ compiler.
873
Tim Petersabf925f2001-09-28 21:53:42 +0000874C API
875
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000876- The documentation for the tp_compare slot is updated to require that
877 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
878 not correct. This is not yet enforced but will be enforced in
879 Python 2.3; even later, we may use -2 to indicate errors and +2 for
880 "NotImplemented". Right now, -1 should be used for an error return.
881
Tim Petersd38b1c72001-09-30 05:09:37 +0000882- PyLong_AsLongLong() now accepts int (as well as long) arguments.
883 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
884 as long) arguments.
885
Guido van Rossum3c288632001-10-16 21:13:49 +0000886- PyThread_start_new_thread() now returns a long int giving the thread
887 ID, if one can be calculated; it returns -1 for error, 0 if no
888 thread ID is calculated (this is an incompatible change, but only
889 the thread module used this API). This code has only really been
890 tested on Linux and Windows; other platforms please beware (and
891 report any bugs or strange behavior).
892
Guido van Rossum1c486092001-10-19 02:05:35 +0000893- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
894 input.
895
Tim Petersabf925f2001-09-28 21:53:42 +0000896New platforms
897
898Tests
899
900Windows
901
Tim Peters04cf1d32001-10-09 22:39:40 +0000902- Installer: If you install IDLE, and don't disable file-extension
903 registration, a new "Edit with IDLE" context (right-click) menu entry
904 is created for .py and .pyw files.
905
Tim Peters1ce3cf72001-10-01 17:58:40 +0000906- The signal module now supports SIGBREAK on Windows, thanks to Steven
907 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
908 action remains to call Win32 ExitProcess(). This can be changed via
909 signal.signal(). For example:
910
911 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
912 # (SIGINT) behavior.
913 import signal
914 signal.signal(signal.SIGBREAK,
915 signal.default_int_handler)
916
917 try:
918 while 1:
919 pass
920 except KeyboardInterrupt:
921 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
922 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
923 # program without the possibility for any Python-level cleanup).
924 print "Clean exit"
925
Tim Petersabf925f2001-09-28 21:53:42 +0000926
Tim Petersb07352e2001-09-08 01:25:47 +0000927What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000928Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000929===========================
930
Guido van Rossum808eea72001-09-25 04:15:41 +0000931Type/class unification and new-style classes
932
933- pydoc and inspect are now aware of new-style classes;
934 e.g. help(list) at the interactive prompt now shows proper
935 documentation for all operations on list objects.
936
937- Applications using Jim Fulton's ExtensionClass module can now safely
938 be used with Python 2.2. In particular, Zope 2.4.1 now works with
939 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
940 examples also work again. It is hoped that Gtk and Boost also work
941 with 2.2a4 and beyond. (If you can confirm this, please write
942 webmaster@python.org; if there are still problems, please open a bug
943 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000944
Tim Peters66c1a522001-09-24 21:17:50 +0000945- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000946 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +0000947 in the constructed property object. fget, fset and fdel weren't
948 discoverable from Python in 2.2a3. __doc__ is new, and allows to
949 associate a docstring with a property.
950
Guido van Rossum808eea72001-09-25 04:15:41 +0000951- Comparison overloading is now more completely implemented. For
952 example, a str subclass instance can properly be compared to a str
953 instance, and it can properly overload comparison. Ditto for most
954 other built-in object types.
955
956- The repr() of new-style classes has changed; instead of <type
957 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
958 *except* for built-in types, which are still rendered as <type
959 'Foo'> (to avoid upsetting existing code that might parse or
960 otherwise rely on repr() of certain type objects).
961
962- The repr() of new-style objects is now always <Foo object at XXX>;
963 previously, it was sometimes <Foo instance at XXX>.
964
965- For new-style classes, what was previously called __getattr__ is now
966 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000967 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000968 one in classic classes is defined which is called only if regular
969 attribute access raises AttributeError; to catch *all* attribute
970 access, you can use __getattribute__ (for new-style classes). If
971 both are defined, __getattribute__ is called first, and if it raises
972 AttributeError, __getattr__ is called.
973
974- The __class__ attribute of new-style objects can be assigned to.
975 The new class must have the same C-level object layout as the old
976 class.
977
978- The builtin file type can be subclassed now. In the usual pattern,
979 "file" is the name of the builtin type, and file() is a new builtin
980 constructor, with the same signature as the builtin open() function.
981 file() is now the preferred way to open a file.
982
983- Previously, __new__ would only see sequential arguments passed to
984 the type in a constructor call; __init__ would see both sequential
985 and keyword arguments. This made no sense whatsoever any more, so
986 now both __new__ and __init__ see all arguments.
987
988- Previously, hash() applied to an instance of a subclass of str or
989 unicode always returned 0. This has been repaired.
990
991- Previously, an operation on an instance of a subclass of an
992 immutable type (int, long, float, complex, tuple, str, unicode),
993 where the subtype didn't override the operation (and so the
994 operation was handled by the builtin type), could return that
995 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000996 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +0000997 with the same value as s.
998
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000999- Provisional support for pickling new-style objects has been added.
1000
Guido van Rossum808eea72001-09-25 04:15:41 +00001001Core
1002
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001003- file.writelines() now accepts any iterable object producing strings.
1004
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001005- PyUnicode_FromEncodedObject() now works very much like
1006 PyObject_Str(obj) in that it tries to use __str__/tp_str
1007 on the object if the object is not a string or buffer. This
1008 makes unicode() behave like str() when applied to non-string/buffer
1009 objects.
1010
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001011- PyFile_WriteObject now passes Unicode objects to the file's write
1012 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001013 of a print statement must support Unicode objects, i.e. they must
1014 at least convert them into ASCII strings.
1015
Guido van Rossum624c8af2001-09-18 15:21:04 +00001016- Thread scheduling on Solaris should be improved; it is no longer
1017 necessary to insert a small sleep at the start of a thread in order
1018 to let other runnable threads be scheduled.
1019
Tim Petersb07352e2001-09-08 01:25:47 +00001020Library
1021
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001022- StringIO.StringIO instances and cStringIO.StringIO instances support
1023 read character buffer compatible objects for their .write() methods.
1024 These objects are converted to strings and then handled as such
1025 by the instances.
1026
Barry Warsaw2f600732001-09-24 04:28:10 +00001027- The "email" package has been added. This is basically a port of the
1028 mimelib package <http://sf.net/projects/mimelib> with API changes
1029 and some implementations updated to use iterators and generators.
1030
Tim Peters8a9c2842001-09-22 21:30:22 +00001031- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1032 restores the ability of Tools/scripts/ndiff.py to start producing output
1033 before the entire comparison is complete.
1034
Barry Warsaw58b072d2001-09-22 04:44:21 +00001035- StringIO.StringIO instances and cStringIO.StringIO instances support
1036 iteration just like file objects (i.e. their .readline() method is
1037 called for each iteration until it returns an empty string).
1038
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001039- The codecs module has grown four new helper APIs to access
1040 builtin codecs: getencoder(), getdecoder(), getreader(),
1041 getwriter().
1042
Guido van Rossum624c8af2001-09-18 15:21:04 +00001043- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1044 simplifies writing XML RPC servers.
1045
Barry Warsaw647d5e82001-09-28 17:01:02 +00001046- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001047 after interpretation of symbolic links. On non-Unix systems, this
1048 is an alias for os.path.abspath().
1049
Tim Peters16a77ad2001-09-08 04:00:12 +00001050- operator.indexOf() (PySequence_Index() in the C API) now works with any
1051 iterable object.
1052
Guido van Rossum624c8af2001-09-18 15:21:04 +00001053- smtplib now supports various authentication and security features of
1054 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001055
Guido van Rossum624c8af2001-09-18 15:21:04 +00001056- hmac: a new module implementing keyed hashing for message
1057 authentication.
1058
1059- mimetypes now recognizes more extensions and file types. At the
1060 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001061
Guido van Rossum624c8af2001-09-18 15:21:04 +00001062- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001063 Python 2.2 bytecode generation. It has also been promoted from a
1064 Tool to a standard library package. (Tools/compiler still exists as
1065 a sample driver.)
1066
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001067Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001068
Tim Petersb07352e2001-09-08 01:25:47 +00001069Build
1070
Guido van Rossum624c8af2001-09-18 15:21:04 +00001071- Large file support (LFS) is now automatic when the platform supports
1072 it; no more manual configuration tweaks are needed. On Linux, at
1073 least, it's possible to have a system whose C library supports large
1074 files but whose kernel doesn't; in this case, large file support is
1075 still enabled but doesn't do you any good unless you upgrade your
1076 kernel or share your Python executable with another system whose
1077 kernel has large file support.
1078
1079- The configure script now supplies plausible defaults in a
1080 cross-compilation environment. This doesn't mean that the supplied
1081 values are always correct, or that cross-compilation now works
1082 flawlessly -- but it's a first step (and it shuts up most of
1083 autoconf's warnings about AC_TRY_RUN).
1084
1085- The Unix build is now a bit less chatty, courtesy of the parser
1086 generator. The build is completely silent (except for errors) when
1087 using "make -s", thanks to a -q option to setup.py.
1088
Tim Petersb07352e2001-09-08 01:25:47 +00001089C API
1090
Guido van Rossum624c8af2001-09-18 15:21:04 +00001091- The "structmember" API now supports some new flag bits to deny read
1092 and/or write access to attributes in restricted execution mode.
1093
Tim Petersb07352e2001-09-08 01:25:47 +00001094New platforms
1095
Guido van Rossum624c8af2001-09-18 15:21:04 +00001096- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1097 (http://familiar.handhelds.org).
1098
Tim Petersb07352e2001-09-08 01:25:47 +00001099Tests
1100
Tim Peters8a9c2842001-09-22 21:30:22 +00001101- The "classic" standard tests, which work by comparing stdout to
1102 an expected-output file under Lib/test/output/, no longer stop at
1103 the first mismatch. Instead the test is run to completion, and a
1104 variant of ndiff-style comparison is used to report all differences.
1105 This is much easier to understand than the previous style of reporting.
1106
1107- The unittest-based standard tests now use regrtest's test_main()
1108 convention, instead of running as a side-effect of merely being
1109 imported. This allows these tests to be run in more natural and
1110 flexible ways as unittests, outside the regrtest framework.
1111
1112- regrtest.py is much better integrated with unittest and doctest now,
1113 especially in regard to reporting errors.
1114
Tim Petersb07352e2001-09-08 01:25:47 +00001115Windows
1116
Guido van Rossum624c8af2001-09-18 15:21:04 +00001117- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001118 that support it (NTFS under Windows 2000). See "What's New in
1119 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001120
Tim Petersb07352e2001-09-08 01:25:47 +00001121
Tim Petersedc99312001-08-22 21:36:50 +00001122What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001123Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001124===========================
1125
1126Core
1127
Tim Peters9fffa3e2001-09-04 05:14:19 +00001128- Conversion of long to float now raises OverflowError if the long is too
1129 big to represent as a C double.
1130
Tim Peters32f453e2001-09-03 08:35:41 +00001131- The 3-argument builtin pow() no longer allows a third non-None argument
1132 if either of the first two arguments is a float, or if both are of
1133 integer types and the second argument is negative (in which latter case
1134 the arguments are converted to float, so this is really the same
1135 restriction).
1136
Tim Peters5d2b77c2001-09-03 05:47:38 +00001137- The builtin dir() now returns more information, and sometimes much
1138 more, generally naming all attributes of an object, and all attributes
1139 reachable from the object via its class, and from its class's base
1140 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1141 an empty list. In 2.2a3,
1142
1143 >>> dir([])
1144 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1145 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1146 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1147 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1148 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1149 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1150 'reverse', 'sort']
1151
1152 dir(module) continues to return only the module's attributes, though.
1153
Tim Petersbdee63f2001-09-02 03:40:59 +00001154- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001155 than raising OverflowError. This is a partial implementation of PEP
1156 237. You can use -Wdefault::OverflowWarning to enable a warning for
1157 this situation, and -Werror::OverflowWarning to revert to the old
1158 OverflowError exception.
1159
Guido van Rossum61c345f2001-09-04 03:26:15 +00001160- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001161 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001162 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1163 -Qold, meaning the / operator has its classic meaning and no
1164 warnings are issued. Using -Qwarn issues a run-time warning about
1165 all uses of classic division for int and long arguments; -Qwarnall
1166 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001167 (for use with fixdiv.py).
1168 [Note: the remainder of this paragraph (preserved below) became
1169 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1170 <obsolete>
1171 Using -Qnew is questionable; it turns on new division by default, but
1172 only in the __main__ module. You can usefully combine -Qwarn or
1173 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1174 warns about classic division everywhere else.
1175 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001176
Tim Petersbdee63f2001-09-02 03:40:59 +00001177- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001178 long, float, str, unicode, and tuple. (The types complex, list and
1179 dictionary can also be subclassed; this was introduced earlier.)
1180 Note that restrictions apply when subclassing immutable built-in
1181 types: you can only affect the value of the instance by overloading
1182 __new__. You can add mutable attributes, and the subclass instances
1183 will have a __dict__ attribute, but you cannot change the "value"
1184 (as implemented by the base class) of an immutable subclass instance
1185 once it is created.
1186
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001187- The dictionary constructor now takes an optional argument, a
1188 mapping-like object, and initializes the dictionary from its
1189 (key, value) pairs.
1190
Tim Petersbdee63f2001-09-02 03:40:59 +00001191- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001192 "cooperative super calls" in a multiple inheritance setting. For an
1193 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1194
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001195- A new built-in type, property, has been added. This enables the
1196 creation of "properties". These are attributes implemented by
1197 getter and setter functions (or only one of these for read-only or
1198 write-only attributes), without the need to override __getattr__.
1199 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001200
Tim Petersbdee63f2001-09-02 03:40:59 +00001201- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001202 liberalized, to allow leading zeroes. Examples of literals now
1203 legal that were SyntaxErrors before:
1204
1205 00.0 0e3 0100j 07.5 00000000000000000008.
1206
Tim Petersbdee63f2001-09-02 03:40:59 +00001207- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001208 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1209
Tim Petersedc99312001-08-22 21:36:50 +00001210Library
1211
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001212- telnetlib includes symbolic names for the options, and support for
1213 setting an option negotiation callback.
1214
Tim Petersa40c7932001-09-05 22:36:56 +00001215- The new C standard no longer requires that math libraries set errno to
1216 ERANGE on overflow. For platform libraries that exploit this new
1217 freedom, Python's overflow-checking was wholly broken. A new overflow-
1218 checking scheme attempts to repair that, but may not be reliable on all
1219 platforms (C doesn't seem to provide anything both useful and portable
1220 in this area anymore).
1221
Martin v. Löwis44f86962001-09-05 13:44:54 +00001222- Asynchronous timeout actions are available through the new class
1223 threading.Timer.
1224
Tim Peters78526162001-09-05 00:53:45 +00001225- math.log and math.log10 now return sensible results for even huge
1226 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1227
Tim Petersbdee63f2001-09-02 03:40:59 +00001228- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001229 currently held. See the docs for the imp module.
1230
Tim Petersbdee63f2001-09-02 03:40:59 +00001231- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001232 dumps containing ints written on platforms where Python ints are 8 bytes.
1233 When read on a box where Python ints are 4 bytes, such values are
1234 converted to Python longs.
1235
Tim Petersbdee63f2001-09-02 03:40:59 +00001236- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001237 code objects is no longer allowed. This plugs a security hole.
1238
Steve Purcell6091cd62001-09-06 16:05:17 +00001239- unittest.TestResult instances no longer store references to tracebacks
1240 generated by test failures. This prevents unexpected dangling references
1241 to objects that should be garbage collected between tests.
1242
Tim Petersedc99312001-08-22 21:36:50 +00001243Tools
1244
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001245- Tools/scripts/fixdiv.py has been added which can be used to fix
1246 division operators as per PEP 238.
1247
Tim Petersedc99312001-08-22 21:36:50 +00001248Build
1249
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001250- If you are an adventurous person using Mac OS X you may want to look at
1251 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1252 application, which can be used for experimenting with Carbon or Cocoa.
1253 Discussion of this on pythonmac-sig, please.
1254
Tim Peters7eea37e2001-09-04 22:08:56 +00001255C API
1256
1257- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001258
Tim Peters9fffa3e2001-09-04 05:14:19 +00001259- Note that PyLong_AsDouble can fail! This has always been true, but no
1260 callers checked for it. It's more likely to fail now, because overflow
1261 errors are properly detected now. The proper way to check:
1262
1263 double x = PyLong_AsDouble(some_long_object);
1264 if (x == -1.0 && PyErr_Occurred()) {
1265 /* The conversion failed. */
1266 }
1267
Tim Petersbdee63f2001-09-02 03:40:59 +00001268- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001269 compile but will not participate in GC. To upgrade an extension
1270 module:
1271
1272 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001273
Neil Schemenauer4042c692001-08-30 15:38:01 +00001274 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1275 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001276
Neil Schemenauer4042c692001-08-30 15:38:01 +00001277 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1278 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001279
Neil Schemenauer4042c692001-08-30 15:38:01 +00001280 - remove PyGC_HEAD_SIZE from object size calculations
1281
1282 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1283
Tim Petersbdee63f2001-09-02 03:40:59 +00001284- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001285 These can be used safely to construct string objects from a
1286 sprintf-style format string (similar to the format string supported
1287 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001288
Tim Petersedc99312001-08-22 21:36:50 +00001289New platforms
1290
Tim Petersb7da0902001-09-02 23:01:43 +00001291- Stephen Hansen contributed patches sufficient to get a clean compile
1292 under Borland C (Windows), but he reports problems running it and ran
1293 out of time to complete the port. Volunteers? Expect a MemoryError
1294 when importing the types module; this is probably shallow, and
1295 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001296
Tim Petersedc99312001-08-22 21:36:50 +00001297Tests
1298
1299Windows
1300
Tim Peters6e13a562001-09-06 00:32:15 +00001301- Large file support is now enabled on Win32 platforms as well as on
1302 Win64. This means that, for example, you can use f.tell() and f.seek()
1303 to manipulate files larger than 2 gigabytes (provided you have enough
1304 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001305 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1306 filesize limit, and large file support makes no difference there.
1307 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1308 NTFS has no practical limit on file size, and files of any size can be
1309 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001310
Tim Petersbdee63f2001-09-02 03:40:59 +00001311- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001312 points to command.com (patch from Brian Quinlan).
1313
Tim Petersedc99312001-08-22 21:36:50 +00001314
Tim Peters20f51a72001-07-21 02:31:40 +00001315What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001316Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001317===========================
1318
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001319Build
1320
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001321- Tim Peters developed a brand new Windows installer using Wise 8.1,
1322 generously donated to us by Wise Solutions.
1323
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001324- configure supports a new option --enable-unicode, with the values
1325 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1326 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001327
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001328- A new configure option --enable-framework builds a Mac OS X framework,
1329 which "make frameworkinstall" will install. This provides a starting
1330 point for more mac-like functionality, join pythonmac-sig@python.org
1331 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001332
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001333- The NeXT platform is no longer supported.
1334
1335- The `new' module is now statically linked.
1336
Tim Peters0afb6092001-08-15 06:06:44 +00001337Tools
1338
1339- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001340 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001341 the module docstring for details.
1342
Tim Peters20f51a72001-07-21 02:31:40 +00001343Tests
1344
Tim Peters5e824c32001-08-12 22:25:01 +00001345- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001346 platforms, allowing to give clearer test result output. regrtest
1347 also has optional --use/-u switch to run normally disabled tests
1348 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001349
Tim Peters20f51a72001-07-21 02:31:40 +00001350- Several new tests in the standard test suite, with special thanks to
1351 Nick Mathewson.
1352
1353Core
1354
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001355- The floor division operator // has been added as outlined in PEP
1356 238. The / operator still provides classic division (and will until
1357 Python 3.0) unless "from __future__ import division" is included, in
1358 which case the / operator will provide true division. The operator
1359 module provides truediv() and floordiv() functions. Augmented
1360 assignment variants are included, as are the equivalent overloadable
1361 methods and C API methods. See the PEP for a full discussion:
1362 <http://python.sf.net/peps/pep-0238.html>
1363
Tim Peters6cd6a822001-08-17 22:11:27 +00001364- Future statements are now effective in simulated interactive shells
1365 (like IDLE). This should "just work" by magic, but read Michael
1366 Hudson's "Future statements in simulated shells" PEP 264 for full
1367 details: <http://python.sf.net/peps/pep-0264.html>.
1368
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001369- The type/class unification (PEP 252-253) was integrated into the
1370 trunk and is not so tentative any more (the exact specification of
1371 some features is still tentative). A lot of work has done on fixing
1372 bugs and adding robustness and features (performance still has to
1373 come a long way).
1374
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001375- Warnings about a mismatch in the Python API during extension import
1376 now use the Python warning framework (which makes it possible to
1377 write filters for these warnings).
1378
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001379- A function's __dict__ (aka func_dict) will now always be a
1380 dictionary. It used to be possible to delete it or set it to None,
1381 but now both actions raise TypeErrors. It is still legal to set it
1382 to a dictionary object. Getting func.__dict__ before any attributes
1383 have been assigned now returns an empty dictionary instead of None.
1384
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001385- A new command line option, -E, was added which disables the use of
1386 all environment variables, or at least those that are specifically
1387 significant to Python. Usually those have a name starting with
1388 "PYTHON". This was used to fix a problem where the tests fail if
1389 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1390 older distribution.
1391
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001392Library
1393
Tim Peters5e824c32001-08-12 22:25:01 +00001394- New class Differ and new functions ndiff() and restore() in difflib.py.
1395 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001396 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001397
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001398- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1399 value using the minimal quoting required for the value; more
1400 reliable than using xml.sax.saxutils.escape() for attribute values.
1401
1402- Readline completion support for cmd.Cmd was added.
1403
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001404- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1405
1406- Added function threading.BoundedSemaphore()
1407
1408- Added Ka-Ping Yee's cgitb.py module.
1409
1410- The `new' module now exposes the CO_xxx flags.
1411
Martin v. Löwis560da622001-11-24 09:24:51 +00001412- The gc module offers the get_referents function.
1413
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001414New platforms
1415
1416C API
1417
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001418- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1419 which provide a cross-platform implementations for the
1420 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1421 the standard sprintf() and vsprintf() C lib APIs, these versions
1422 apply bounds checking on the used buffer which enhances protection
1423 against buffer overruns.
1424
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001425- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001426 and extensions using different Unicode widths is rendered next to
1427 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001428 will result in an ImportError. Unicode extensions writers must make
1429 sure to check the Unicode width compatibility in their extensions by
1430 using at least one of the mangled Unicode APIs in the extension.
1431
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001432- Two new flags METH_NOARGS and METH_O are available in method definition
1433 tables to simplify implementation of methods with no arguments and a
1434 single untyped argument. Calling such methods is more efficient than
1435 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1436 deprecated.
1437
Tim Petersc1731372001-08-04 08:12:36 +00001438Windows
1439
1440- "import module" now compiles module.pyw if it exists and nothing else
1441 relevant is found.
1442
Tim Peters20f51a72001-07-21 02:31:40 +00001443
Guido van Rossum55a78992001-07-17 17:22:32 +00001444What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001445Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001446===========================
1447
1448Core
Tim Petersa814db52001-05-14 07:05:58 +00001449
Tim Peters6d6c1a32001-08-02 04:15:00 +00001450- TENTATIVELY, a large amount of code implementing much of what's
1451 described in PEP 252 (Making Types Look More Like Classes) and PEP
1452 253 (Subtyping Built-in Types) was added. This will be released
1453 with Python 2.2a1. Documentation will be provided separately
1454 through http://www.python.org/2.2/. The purpose of releasing this
1455 with Python 2.2a1 is to test backwards compatibility. It is
1456 possible, though not likely, that a decision is made not to release
1457 this code as part of 2.2 final, if any serious backwards
1458 incompapatibilities are found during alpha testing that cannot be
1459 repaired.
1460
Guido van Rossum55a78992001-07-17 17:22:32 +00001461- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001462 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001463 more 'yield' statements. See PEP 255. Since this adds a new
1464 keyword to the language, this feature must be enabled by including a
1465 future statement: "from __future__ import generators" (see PEP 236).
1466 Generators will become a standard feature in a future release
1467 (probably 2.3). Without this future statement, 'yield' remains an
1468 ordinary identifier, but a warning is issued each time it is used.
1469 (These warnings currently don't conform to the warnings framework of
1470 PEP 230; we intend to fix this in 2.2a2.)
1471
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001472- The UTF-16 codec was modified to be more RFC compliant. It will now
1473 only remove BOM characters at the start of the string and then
1474 only if running in native mode (UTF-16-LE and -BE won't remove a
1475 leading BMO character).
1476
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001477- Strings now have a new method .decode() to complement the already
1478 existing .encode() method. These two methods provide direct access
1479 to the corresponding decoders and encoders of the registered codecs.
1480
1481 To enhance the usability of the .encode() method, the special
1482 casing of Unicode object return values was dropped (Unicode objects
1483 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001484
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001485 Both methods will now return whatever the codec in charge of the
1486 requested encoding returns as object, e.g. Unicode codecs will
1487 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1488 will return u"äöü"). This enables codec writer to create codecs
1489 for various simple to use conversions.
1490
1491 New codecs were added to demonstrate these new features (the .encode()
1492 and .decode() columns indicate the type of the returned objects):
1493
1494 Name | .encode() | .decode() | Description
1495 ----------------------------------------------------------------------
1496 uu | string | string | UU codec (e.g. for email)
1497 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001498 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001499 zlib | string | string | zlib compression
1500 hex | string | string | 2-byte hex codec
1501 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1502
Mark Hammond2a0af792001-05-14 03:09:36 +00001503- Some operating systems now support the concept of a default Unicode
1504 encoding for file system operations. Notably, Windows supports 'mbcs'
1505 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001506 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001507 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001508
1509 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001510 functions that return filenames (such as os.listdir()) to return Python
1511 string objects pre-encoded using the default file system encoding for
1512 the platform. As this encoding is likely to be different from Python's
1513 default encoding, converting this name to a Unicode object before passing
1514 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001515 would attempt to use its default encoding (generally ASCII) rather than
1516 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001517
Tim Petersa814db52001-05-14 07:05:58 +00001518 In general, this change simply removes surprises when working with
1519 Unicode and the file system, making these operations work as you expect,
1520 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001521 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001522
Tim Peters61dff2b2001-05-08 15:43:37 +00001523- Float (and complex) literals in source code were evaluated to full
1524 precision only when running from a .py file; the same code loaded from a
1525 .pyc (or .pyo) file could suffer numeric differences starting at about the
1526 12th significant decimal digit. For example, on a machine with IEEE-754
1527 floating arithmetic,
1528
1529 x = 9007199254740992.0
1530 print long(x)
1531
1532 printed 9007199254740992 if run directly from .py, but 9007199254740000
1533 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1534 str(float) instead of repr(float) when building code objects. marshal
1535 now uses repr(float) instead, which should reproduce floats to full
1536 machine precision (assuming the platform C float<->string I/O conversion
1537 functions are of good quality).
1538
1539 This may cause floating-point results to change in some cases, and
1540 usually for the better, but may also cause numerically unstable
1541 algorithms to break.
1542
Tim Peters2f228e72001-05-13 00:19:31 +00001543- The implementation of dicts suffers fewer collisions, which has speed
1544 benefits. However, the order in which dict entries appear in dict.keys(),
1545 dict.values() and dict.items() may differ from previous releases for a
1546 given dict. Nothing is defined about this order, so no program should
1547 rely on it. Nevertheless, it's easy to write test cases that rely on the
1548 order by accident, typically because of printing the str() or repr() of a
1549 dict to an "expected results" file. See Lib/test/test_support.py's new
1550 sortdict(dict) function for a simple way to display a dict in sorted
1551 order.
1552
Tim Peters7a3bfc32001-06-12 01:22:22 +00001553- Many other small changes to dicts were made, resulting in faster
1554 operation along the most common code paths.
1555
Guido van Rossum10315822001-05-01 20:54:30 +00001556- Dictionary objects now support the "in" operator: "x in dict" means
1557 the same as dict.has_key(x).
1558
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001559- The update() method of dictionaries now accepts generic mapping
1560 objects. Specifically the argument object must support the .keys()
1561 and __getitem__() methods. This allows you to say, for example,
1562 {}.update(UserDict())
1563
Guido van Rossum10315822001-05-01 20:54:30 +00001564- Iterators were added; this is a generalized way of providing values
1565 to a for loop. See PEP 234. There's a new built-in function iter()
1566 to return an iterator. There's a new protocol to get the next value
1567 from an iterator using the next() method (in Python) or the
1568 tp_iternext slot (in C). There's a new protocol to get iterators
1569 using the __iter__() method (in Python) or the tp_iter slot (in C).
1570 Iterating (i.e. a for loop) over a dictionary generates its keys.
1571 Iterating over a file generates its lines.
1572
Tim Petersf553f892001-05-01 20:45:31 +00001573- The following functions were generalized to work nicely with iterator
1574 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001575 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001576 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1577 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001578 join() method of strings
1579 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001580 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1581 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001582 right-hand side of assignment statements with multiple targets, such as
1583 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001584
Tim Petersd85e1022001-05-11 21:51:48 +00001585- Accessing module attributes is significantly faster (for example,
1586 random.random or os.path or yourPythonModule.yourAttribute).
1587
Tim Peterse63415e2001-05-08 04:38:29 +00001588- Comparing dictionary objects via == and != is faster, and now works even
1589 if the keys and values don't support comparisons other than ==.
1590
Tim Peters95bf9392001-05-10 08:32:44 +00001591- Comparing dictionaries in ways other than == and != is slower: there were
1592 insecurities in the dict comparison implementation that could cause Python
1593 to crash if the element comparison routines for the dict keys and/or
1594 values mutated the dicts. Making the code bulletproof slowed it down.
1595
Tim Peterseb28ef22001-06-02 05:27:19 +00001596- Collisions in dicts are resolved via a new approach, which can help
1597 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001598 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001599 faster now. Thanks to Christian Tismer for pointing out the cause and
1600 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001601
Tim Peters52e155e2001-06-16 05:42:57 +00001602- repr() is much faster for large containers (dict, list, tuple).
1603
1604
Tim Petersa814db52001-05-14 07:05:58 +00001605Library
1606
Fred Drake960fdf92001-07-20 18:38:26 +00001607- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1608 were added to the string module. These a locale-indenpendent
1609 constants, unlike letters, lowercase, and uppercase. These are now
1610 use in appropriate locations in the standard library.
1611
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001612- The flags used in dlopen calls can now be configured using
1613 sys.setdlopenflags and queried using sys.getdlopenflags.
1614
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001615- Fredrik Lundh's xmlrpclib is now a standard library module. This
1616 provides full client-side XML-RPC support. In addition,
1617 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1618 one asyncore-based). Thanks to Eric Raymond for the documentation.
1619
Guido van Rossum643d3912001-07-05 14:46:25 +00001620- The xrange() object is simplified: it no longer supports slicing,
1621 repetition, comparisons, efficient 'in' checking, the tolist()
1622 method, or the start, stop and step attributes. See PEP 260.
1623
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001624- A new function fnmatch.filter to filter lists of file names was added.
1625
Barry Warsawffd674d2001-05-22 16:00:10 +00001626- calendar.py uses month and day names based on the current locale.
1627
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001628- strop is now *really* obsolete (this was announced before with 1.6),
1629 and issues DeprecationWarning when used (except for the four items
1630 that are still imported into string.py).
1631
Tim Petersa814db52001-05-14 07:05:58 +00001632- Cookie.py now sorts key+value pairs by key in output strings.
1633
1634- pprint.isrecursive(object) didn't correctly identify recursive objects.
1635 Now it does.
1636
Tim Peters95b3f782001-05-14 18:39:41 +00001637- pprint functions now much faster for large containers (tuple, list, dict).
1638
Tim Peters7b9542a2001-06-10 23:40:19 +00001639- New 'q' and 'Q' format codes in the struct module, corresponding to C
1640 types "long long" and "unsigned long long" (on Windows, __int64). In
1641 native mode, these can be used only when the platform C compiler supports
1642 these types (when HAVE_LONG_LONG is #define'd by the Python config
1643 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001644 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1645 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001646
Guido van Rossum83213cc2001-06-12 16:48:52 +00001647- The site module installs a new built-in function 'help' that invokes
1648 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1649 it displays a message reminding the user to use 'help()' or
1650 'help(object)'.
1651
Tim Petersa814db52001-05-14 07:05:58 +00001652Tests
1653
1654- New test_mutants.py runs dict comparisons where the key and value
1655 comparison operators mutute the dicts randomly during comparison. This
1656 rapidly causes Python to crash under earlier releases (not for the faint
1657 of heart: it can also cause Win9x to freeze or reboot!).
1658
1659- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001660 pprint.isreadable() return sensible results. Also verifies that simple
1661 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001662
Tim Peters4324aa32001-05-28 22:30:08 +00001663C API
1664
1665- Removed the unused last_is_sticky argument from the internal
1666 _PyTuple_Resize(). If this affects you, you were cheating.
1667
1668
Guido van Rossum55a78992001-07-17 17:22:32 +00001669======================================================================
1670
1671
Guido van Rossumffe13be2001-04-16 18:46:45 +00001672What's New in Python 2.1 (final)?
1673=================================
1674
1675We only changed a few things since the last release candidate, all in
1676Python library code:
1677
1678- A bug in the locale module was fixed that affected locales which
1679 define no grouping for numeric formatting.
1680
1681- A few bugs in the weakref module's implementations of weak
1682 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1683 and the test suite was updated to check for these bugs.
1684
1685- An old bug in the os.path.walk() function (introduced in Python
1686 2.0!) was fixed: a non-existent file would cause an exception
1687 instead of being ignored.
1688
1689- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1690 PyChecker.
1691
1692
Guido van Rossum5b08f132001-04-16 02:05:23 +00001693What's New in Python 2.1c2?
1694===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001695
Guido van Rossum5b08f132001-04-16 02:05:23 +00001696A flurry of small changes, and one showstopper fixed in the nick of
1697time made it necessary to release another release candidate. The list
1698here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001699
Guido van Rossum5b08f132001-04-16 02:05:23 +00001700Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001701
Guido van Rossum5b08f132001-04-16 02:05:23 +00001702- Tim discovered a nasty bug in the dictionary code, caused by
1703 PyDict_Next() calling dict_resize(), and the GC code's use of
1704 PyDict_Next() violating an assumption in dict_items(). This was
1705 fixed with considerable amounts of band-aid, but the net effect is a
1706 saner and more robust implementation.
1707
1708- Made a bunch of symbols static that were accidentally global.
1709
1710Build and Ports
1711
1712- The setup.py script didn't check for a new enough version of zlib
1713 (1.1.3 is needed). Now it does.
1714
1715- Changed "make clean" target to also remove shared libraries.
1716
1717- Added a more general warning about the SGI Irix optimizer to README.
1718
1719Library
1720
1721- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1722 omitted the slash between host and file.html.
1723
1724- The mailbox module's _Mailbox class contained a completely broken
1725 and undocumented seek() method. Ripped it out.
1726
1727- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1728 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1729
1730- Fixed a few last-minute bugs in unittest.
1731
1732Extensions
1733
1734- Reverted the patch to the OpenSSL code in socketmodule.c to support
1735 RAND_status() and the EGD, and the subsequent patch that tried to
1736 fix it for pre-0.9.5 versions; the problem with the patch is that on
1737 some systems it issues a warning whenever socket is imported, and
1738 that's unacceptable.
1739
1740Tests
1741
1742- Fixed the pickle tests to work with "import test.test_pickle".
1743
1744- Tweaked test_locale.py to actually run the test Windows.
1745
1746- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1747 not "wb" (which is not a valid mode at all).
1748
1749- Fix pstats browser crashes. Import readline if it exists to make
1750 the user interface nicer.
1751
1752- Add "import thread" to the top of test modules that import the
1753 threading module (test_asynchat and test_threadedtempfile). This
1754 prevents test failures caused by a broken threading module resulting
1755 from a previously caught failed import.
1756
1757- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1758 needed on some platforms (e.g. Solaris 8) when the tests are run
1759 twice in succession.
1760
1761- Skip rather than fail test_sunaudiodev if no audio device is found.
1762
1763
1764What's New in Python 2.1c1?
1765===========================
1766
1767This list was significantly updated when 2.1c2 was released; the 2.1c1
1768release didn't mention most changes that were actually part of 2.1c1:
1769
1770Legal
1771
1772- Copyright was assigned to the Python Software Foundation (PSF) and a
1773 PSF license (very similar to the CNRI license) was added.
1774
1775- The CNRI copyright notice was updated to include 2001.
1776
1777Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001778
Guido van Rossumc9932722001-04-12 02:31:27 +00001779- After a public outcry, assignment to __debug__ is no longer illegal;
1780 instead, a warning is issued. It will become illegal in 2.2.
1781
Guido van Rossum5b08f132001-04-16 02:05:23 +00001782- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1783 "%#x" now always prepends "0x", even if the value is zero.
1784
1785- Fixed some nits in the bytecode compiler.
1786
1787- Fixed core dumps when calling certain kinds of non-functions.
1788
1789- Fixed various core dumps caused by reference count bugs.
1790
1791Build and Ports
1792
1793- Use INSTALL_SCRIPT to install script files.
1794
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001795- New port: SCO Unixware 7, by Billy G. Allie.
1796
Guido van Rossum5b08f132001-04-16 02:05:23 +00001797- Updated RISCOS port.
1798
1799- Updated BeOS port and notes.
1800
1801- Various other porting problems resolved.
1802
1803Library
1804
1805- The TERMIOS and SOCKET modules are now truly obsolete and
1806 unnecessary. Their symbols are incorporated in the termios and
1807 socket modules.
1808
1809- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1810 better tests for pickling.
1811
1812- threading: make Condition.wait() robust against KeyboardInterrupt.
1813
1814- zipfile: add support to zipfile to support opening an archive
1815 represented by an open file rather than a file name. Fix bug where
1816 the archive was not properly closed. Fixed a bug in this bugfix
1817 where flush() was called for a read-only file.
1818
1819- imputil: added an uninstall() method to the ImportManager.
1820
1821- Canvas: fixed bugs in lower() and tkraise() methods.
1822
1823- SocketServer: API change (added overridable close_request() method)
1824 so that the TCP server can explicitly close the request.
1825
1826- pstats: Eric Raymond added a simple interactive statistics browser,
1827 invoked when the module is run as a script.
1828
1829- locale: fixed a problem in format().
1830
1831- webbrowser: made it work when the BROWSER environment variable has a
1832 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1833 KDE 2. Fixed some other nits.
1834
1835- unittest: changes to allow using a different exception than
1836 AssertionError, and added a few more function aliases. Some other
1837 small changes.
1838
1839- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1840
1841- asynchat: fixed a critical bug in asynchat that slipped through the
1842 2.1b2 release. Fixed another rare bug.
1843
1844- Fix some unqualified except: clauses (always a bad code example).
1845
1846XML
1847
1848- pyexpat: new API get_version_string().
1849
1850- Fixed some minidom bugs.
1851
1852Extensions
1853
1854- Fixed a core dump in _weakref. Removed the weakref.mapping()
1855 function (it adds nothing to the API).
1856
1857- Rationalized the use of header files in the readline module, to make
1858 it compile (albeit with some warnings) with the very recent readline
1859 4.2, without breaking for earlier versions.
1860
1861- Hopefully fixed a buffering problem in linuxaudiodev.
1862
1863- Attempted a fix to make the OpenSSL support in the socket module
1864 work again with pre-0.9.5 versions of OpenSSL.
1865
1866Tests
1867
1868- Added a test case for asynchat and asyncore.
1869
1870- Removed coupling between tests where one test failing could break
1871 another.
1872
1873Tools
1874
1875- Ping added an interactive help browser to pydoc, fixed some nits
1876 in the rest of the pydoc code, and added some features to his
1877 inspect module.
1878
1879- An updated python-mode.el version 4.1 which integrates Ken
1880 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1881 much nicer in XEmacs and Emacs. When stepping through your program
1882 with pdb, in either the shell window or the *Python* window, the
1883 source file and line will be tracked by an arrow. Very cool!
1884
1885- IDLE: syntax warnings in interactive mode are changed into errors.
1886
1887- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001888 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001889
1890- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001891
Barry Warsaw11e89c72001-04-11 20:37:57 +00001892
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001893What's New in Python 2.1 beta 2?
1894================================
1895
Guido van Rossum053ae352001-03-22 14:17:21 +00001896(Unlisted are many fixed bugs, more documentation, etc.)
1897
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001898Core language, builtins, and interpreter
1899
Guido van Rossum053ae352001-03-22 14:17:21 +00001900- The nested scopes work (enabled by "from __future__ import
1901 nested_scopes") is completed; in particular, the future now extends
1902 into code executed through exec, eval() and execfile(), and into the
1903 interactive interpreter.
1904
1905- When calling a base class method (e.g. BaseClass.__init__(self)),
1906 this is now allowed even if self is not strictly spoken a class
1907 instance (e.g. when using metaclasses or the Don Beaudry hook).
1908
1909- Slice objects are now comparable but not hashable; this prevents
1910 dict[:] from being accepted but meaningless.
1911
1912- Complex division is now calculated using less braindead algorithms.
1913 This doesn't change semantics except it's more likely to give useful
1914 results in extreme cases. Complex repr() now uses full precision
1915 like float repr().
1916
1917- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1918
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001919- It is illegal to assign to the name __debug__, which is set when the
1920 interpreter starts. It is effectively a compile-time constant.
1921
1922- A warning will be issued if a global statement for a variable
1923 follows a use or assignment of that variable.
1924
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001925Standard library
1926
Guido van Rossum053ae352001-03-22 14:17:21 +00001927- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1928 inspired by JUnit), is now part of the standard library. You now
1929 have a choice of two testing frameworks: unittest requires you to
1930 write testcases as separate code, doctest gathers them from
1931 docstrings. Both approaches have their advantages and
1932 disadvantages.
1933
1934- A new module Tix was added, which wraps the Tix extension library
1935 for Tk. With that module, it is not necessary to statically link
1936 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1937 require" command. See Demo/tix/.
1938
1939- tzparse.py is now obsolete.
1940
1941- In gzip.py, the seek() and tell() methods are removed -- they were
1942 non-functional anyway, and it's better if callers can test for their
1943 existence with hasattr().
1944
1945Python/C API
1946
1947- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1948 that's already in the dictionary during a PyDict_Next() iteration.
1949 This used to fail occasionally when a dictionary resize operation
1950 could be triggered that would rehash all the keys. All other
1951 modifications to the dictionary are still off-limits during a
1952 PyDict_Next() iteration!
1953
1954- New extended APIs related to passing compiler variables around.
1955
1956- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1957 implement isinstance() and issubclass().
1958
1959- Py_BuildValue() now has a "D" conversion to create a Python complex
1960 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001961
Fred Drake4e262a92001-03-22 18:26:47 +00001962- Extensions types which support weak references must now set the
1963 field allocated for the weak reference machinery to NULL themselves;
1964 this is done to avoid the cost of checking each object for having a
1965 weakly referencable type in PyObject_INIT(), since most types are
1966 not weakly referencable.
1967
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001968- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1969 free variables and cell variables to and from the frame's f_locals.
1970
1971- Variants of several functions defined in pythonrun.h have been added
1972 to support the nested_scopes future statement. The variants all end
1973 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1974 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1975 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001976 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001977
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001978Distutils
1979
1980- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1981 into the release tree.
1982
Tim Peters0e57abf2001-05-02 07:39:38 +00001983- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001984 (an uninstaller, more customization of the installer's display)
1985
1986- from Jack Jansen: added Mac-specific code to generate a dialog for
1987 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001988 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001989 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001990
1991- added 'platforms' and 'keywords' to the set of metadata that can be
1992 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001993
1994- applied patches from Jason Tishler to make the compiler class work with
1995 Cygwin.
1996
1997
Tim Peters2fe289a2001-03-01 22:19:38 +00001998What's New in Python 2.1 beta 1?
1999================================
Tim Petersd66595f2001-02-04 03:09:53 +00002000
2001Core language, builtins, and interpreter
2002
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002003- Following an outcry from the community about the amount of code
2004 broken by the nested scopes feature introduced in 2.1a2, we decided
2005 to make this feature optional, and to wait until Python 2.2 (or at
2006 least 6 months) to make it standard. The option can be enabled on a
2007 per-module basis by adding "from __future__ import nested_scopes" at
2008 the beginning of a module (before any other statements, but after
2009 comments and an optional docstring). See PEP 236 (Back to the
2010 __future__) for a description of the __future__ statement. PEP 227
2011 (Statically Nested Scopes) has been updated to reflect this change,
2012 and to clarify the semantics in a number of endcases.
2013
2014- The nested scopes code, when enabled, has been hardened, and most
2015 bugs and memory leaks in it have been fixed.
2016
2017- Compile-time warnings are now generated for a number of conditions
2018 that will break or change in meaning when nested scopes are enabled:
2019
2020 - Using "from...import *" or "exec" without in-clause in a function
2021 scope that also defines a lambda or nested function with one or
2022 more free (non-local) variables. The presence of the import* or
2023 bare exec makes it impossible for the compiler to determine the
2024 exact set of local variables in the outer scope, which makes it
2025 impossible to determine the bindings for free variables in the
2026 inner scope. To avoid the warning about import *, change it into
2027 an import of explicitly name object, or move the import* statement
2028 to the global scope; to avoid the warning about bare exec, use
2029 exec...in... (a good idea anyway -- there's a possibility that
2030 bare exec will be deprecated in the future).
2031
2032 - Use of a global variable in a nested scope with the same name as a
2033 local variable in a surrounding scope. This will change in
2034 meaning with nested scopes: the name in the inner scope will
2035 reference the variable in the outer scope rather than the global
2036 of the same name. To avoid the warning, either rename the outer
2037 variable, or use a global statement in the inner function.
2038
Neil Schemenauera35c6882001-02-27 04:45:05 +00002039- An optional object allocator has been included. This allocator is
2040 optimized for Python objects and should be faster and use less memory
2041 than the standard system allocator. It is not enabled by default
2042 because of possible thread safety problems. The allocator is only
2043 protected by the Python interpreter lock and it is possible that some
2044 extension modules require a thread safe allocator. The object
2045 allocator can be enabled by providing the "--with-pymalloc" option to
2046 configure.
2047
Tim Petersd66595f2001-02-04 03:09:53 +00002048Standard library
2049
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002050- pyexpat now detects the expat version if expat.h defines it. A
2051 number of additional handlers are provided, which are only available
2052 since expat 1.95. In addition, the methods SetParamEntityParsing and
2053 GetInputContext of Parser objects are available with 1.95.x
2054 only. Parser objects now provide the ordered_attributes and
2055 specified_attributes attributes. A new module expat.model was added,
2056 which offers a number of additional constants if 1.95.x is used.
2057
2058- xml.dom offers the new functions registerDOMImplementation and
2059 getDOMImplementation.
2060
2061- xml.dom.minidom offers a toprettyxml method. A number of DOM
2062 conformance issues have been resolved. In particular, Element now
2063 has an hasAttributes method, and the handling of namespaces was
2064 improved.
2065
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002066- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2067 getting information about live Python code, and pydoc.py, a module
2068 for interactively converting docstrings to HTML or text.
2069 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002070 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002071 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2072 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002073
Tim Peters1eff7962001-03-01 02:31:33 +00002074- New library module difflib.py, primarily packaging the SequenceMatcher
2075 class at the heart of the popular ndiff.py file-comparison tool.
2076
2077- doctest.py (a framework for verifying Python code examples in docstrings)
2078 is now part of the std library.
2079
Tim Petersd66595f2001-02-04 03:09:53 +00002080Windows changes
2081
Guido van Rossume3955a82001-03-02 14:05:59 +00002082- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2083 small GUI that lets you browse the module docstrings using your
2084 default web browser.
2085
Tim Peters1eff7962001-03-01 02:31:33 +00002086- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2087 Platforms) is implemented. See
2088
2089 http://python.sourceforge.net/peps/pep-0235.html
2090
2091 for full details, especially the "Current Lower-Left Semantics" section.
2092 The new Windows import rules are simpler than before:
2093
2094 A. If the PYTHONCASEOK environment variable exists, same as
2095 before: silently accept the first case-insensitive match of any
2096 kind; raise ImportError if none found.
2097
2098 B. Else search sys.path for the first case-sensitive match; raise
2099 ImportError if none found.
2100
2101 The same rules have been implented on other platforms with case-
2102 insensitive but case-preserving filesystems too (including Cygwin, and
2103 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002104
Tim Peters25a9ce32001-02-19 07:06:36 +00002105- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2106 what it's supposed to do (and does do under NT and 2000) via direct
2107 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002108 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002109 all Win9x systems before.
2110
Tim Peters1eff7962001-03-01 02:31:33 +00002111- Build: Subproject _test (effectively) renamed to _testcapi.
2112
Tim Peters2fe289a2001-03-01 22:19:38 +00002113New platforms
2114
2115- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2116 Thanks to Steven Majewski!
2117
2118- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2119 Tishler!
2120
Guido van Rossum9089b272001-03-02 06:49:50 +00002121- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2122 Schwertberger! See RISCOS/README for more information -- it seems
2123 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002124 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002125
Tim Peters25a9ce32001-02-19 07:06:36 +00002126
Tim Petersd7b5e882001-01-25 03:36:26 +00002127What's New in Python 2.1 alpha 2?
2128=================================
Tim Peters40ead762001-01-27 05:35:26 +00002129
Tim Petersd7b5e882001-01-25 03:36:26 +00002130Core language, builtins, and interpreter
2131
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002132- Scopes nest. If a name is used in a function or class, but is not
2133 local, the definition in the nearest enclosing function scope will
2134 be used. One consequence of this change is that lambda statements
2135 could reference variables in the namespaces where the lambda is
2136 defined. In some unusual cases, this change will break code.
2137
2138 In all previous version of Python, names were resolved in exactly
2139 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002140 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002141 function A is defined within a function B, the names bound in B are
2142 not visible in A. The new rules make names bound in B visible in A,
2143 unless A contains a name binding that hides the binding in B.
2144
2145 Section 4.1 of the reference manual describes the new scoping rules
2146 in detail. The test script in Lib/test/test_scope.py demonstrates
2147 some of the effects of the change.
2148
2149 The new rules will cause existing code to break if it defines nested
2150 functions where an outer function has local variables with the same
2151 name as globals or builtins used by the inner function. Example:
2152
2153 def munge(str):
2154 def helper(x):
2155 return str(x)
2156 if type(str) != type(''):
2157 str = helper(str)
2158 return str.strip()
2159
2160 Under the old rules, the name str in helper() is bound to the
2161 builtin function str(). Under the new rules, it will be bound to
2162 the argument named str and an error will occur when helper() is
2163 called.
2164
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002165- The compiler will report a SyntaxError if "from ... import *" occurs
2166 in a function or class scope. The language reference has documented
2167 that this case is illegal, but the compiler never checked for it.
2168 The recent introduction of nested scope makes the meaning of this
2169 form of name binding ambiguous. In a future release, the compiler
2170 may allow this form when there is no possibility of ambiguity.
2171
Tim Peters40ead762001-01-27 05:35:26 +00002172- repr(string) is easier to read, now using hex escapes instead of octal,
2173 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2174
2175 >>> "\texample \r\n" + chr(0) + chr(255)
2176 '\texample \r\n\x00\xff' # in 2.1
2177 '\011example \015\012\000\377' # in 2.0
2178
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002179- Functions are now compared and hashed by identity, not by value, since
2180 the func_code attribute is writable.
2181
Fred Drakefb9d7122001-02-01 20:00:40 +00002182- Weak references (PEP 205) have been added. This involves a few
2183 changes in the core, an extension module (_weakref), and a Python
2184 module (weakref). The weakref module is the public interface. It
2185 includes support for "explicit" weak references, proxy objects, and
2186 mappings with weakly held values.
2187
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002188- A 'continue' statement can now appear in a try block within the body
2189 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002190 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002191
Tim Petersd7b5e882001-01-25 03:36:26 +00002192Standard library
2193
Barry Warsaw30dbd142001-01-31 22:14:01 +00002194- mailbox.py now has a new class, PortableUnixMailbox which is
2195 identical to UnixMailbox but uses a more portable scheme for
2196 determining From_ separators. Also, the constructors for all the
2197 classes in this module have a new optional `factory' argument, which
2198 is a callable used when new message classes must be instantiated by
2199 the next() method.
2200
Tim Petersd7b5e882001-01-25 03:36:26 +00002201- random.py is now self-contained, and offers all the functionality of
2202 the now-deprecated whrandom.py. See the docs for details. random.py
2203 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002204 and restoring the internal state of the generator; and jumpahead(n),
2205 for quickly forcing the internal state to be the same as if n calls to
2206 random() had been made. The latter is particularly useful for multi-
2207 threaded programs, creating one instance of the random.Random() class for
2208 each thread, then using .jumpahead() to force each instance to use a
2209 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002210
Tim Peters0de88fc2001-02-01 04:59:18 +00002211- random.py's seed() function is new. For bit-for-bit compatibility with
2212 prior releases, use the whseed function instead. The new seed function
2213 addresses two problems: (1) The old function couldn't produce more than
2214 about 2**24 distinct internal states; the new one about 2**45 (the best
2215 that can be done in the Wichmann-Hill generator). (2) The old function
2216 sometimes produced identical internal states when passed distinct
2217 integers, and there was no simple way to predict when that would happen;
2218 the new one guarantees to produce distinct internal states for all
2219 arguments in [0, 27814431486576L).
2220
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002221- The socket module now supports raw packets on Linux. The socket
2222 family is AF_PACKET.
2223
Tim Peters9ea17ac2001-02-02 05:57:15 +00002224- test_capi.py is a start at running tests of the Python C API. The tests
2225 are implemented by the new Modules/_testmodule.c.
2226
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002227- A new extension module, _symtable, provides provisional access to the
2228 internal symbol table used by the Python compiler. A higher-level
2229 interface will be added on top of _symtable in a future release.
2230
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002231- Removed the obsolete soundex module.
2232
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002233- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2234 the isSameNode method; NamedNodeMap the get method.
2235
2236- xml.sax.expatreader supports the lexical handler property; it
2237 generates comment, startCDATA, and endCDATA events.
2238
Tim Petersee826f82001-01-31 19:39:44 +00002239Windows changes
2240
2241- Build procedure: the zlib project is built in a different way that
2242 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002243 the zlib binary used. See PCbuild\readme.txt for details. Your old
2244 zlib-related directories can be deleted; you'll need to download fresh
2245 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002246
Tim Peters9ea17ac2001-02-02 05:57:15 +00002247- Build: New subproject _test for the benefit of test_capi.py (see above).
2248
Tim Petersb16c56f2001-02-02 21:24:51 +00002249- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2250 interface to some Python compiler internals).
2251
2252- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002253 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002254
Tim Petersa3a3a032000-11-30 05:22:44 +00002255What's New in Python 2.1 alpha 1?
2256=================================
2257
2258Core language, builtins, and interpreter
2259
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002260- There is a new Unicode companion to the PyObject_Str() API
2261 called PyObject_Unicode(). It behaves in the same way as the
2262 former, but assures that the returned value is an Unicode object
2263 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002264
Guido van Rossumf98eda02001-01-17 15:54:45 +00002265- The comparison operators support "rich comparison overloading" (PEP
2266 207). C extension types can provide a rich comparison function in
2267 the new tp_richcompare slot in the type object. The cmp() function
2268 and the C function PyObject_Compare() first try the new rich
2269 comparison operators before trying the old 3-way comparison. There
2270 is also a new C API PyObject_RichCompare() (which also falls back on
2271 the old 3-way comparison, but does not constrain the outcome of the
2272 rich comparison to a Boolean result).
2273
2274 The rich comparison function takes two objects (at least one of
2275 which is guaranteed to have the type that provided the function) and
2276 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2277 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2278 object, which may be NotImplemented (in which case the tp_compare
2279 slot function is used as a fallback, if defined).
2280
2281 Classes can overload individual comparison operators by defining one
2282 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002283 __ge__. There are no explicit "reflected argument" versions of
2284 these; instead, __lt__ and __gt__ are each other's reflection,
2285 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2286 reflection (similar at the C level). No other implications are
2287 made; in particular, Python does not assume that == is the Boolean
2288 inverse of !=, or that < is the Boolean inverse of >=. This makes
2289 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002290
2291 Classes or types that want to implement (in)equality tests but not
2292 the ordering operators (i.e. unordered types) should implement ==
2293 and !=, and raise an error for the ordering operators.
2294
Guido van Rossuma88479f2001-01-18 14:28:08 +00002295 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002296 Boolean; e.g. a matrix type might want to return a matrix of bits
2297 for A < B, giving elementwise comparisons. Such types should ensure
2298 that any interpretation of their value in a Boolean context raises
2299 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2300 at the C level) to always raise an exception.
2301
Guido van Rossuma88479f2001-01-18 14:28:08 +00002302- Complex numbers use rich comparisons to define == and != but raise
2303 an exception for <, <=, > and >=. Unfortunately, this also means
2304 that cmp() of two complex numbers raises an exception when the two
2305 numbers differ. Since it is not mathematically meaningful to compare
2306 complex numbers except for equality, I hope that this doesn't break
2307 too much code.
2308
Tim Peters3389f192001-02-18 08:48:49 +00002309- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002310 not defined by the language, other than that it's arbitrary but
2311 consistent (see the Reference Manual). An implementation detail changed
2312 in 2.1a1 such that None now compares less than any other object. Code
2313 relying on this new behavior (like code that relied on the previous
2314 behavior) does so at its own risk.
2315
Barry Warsaw573b5412001-01-15 20:43:18 +00002316- Functions and methods now support getting and setting arbitrarily
2317 named attributes (PEP 232). Functions have a new __dict__
2318 (a.k.a. func_dict) which hold the function attributes. Methods get
2319 and set attributes on their underlying im_func. It is a TypeError
2320 to set an attribute on a bound method.
2321
Guido van Rossum051e3352001-01-15 19:11:10 +00002322- The xrange() object implementation has been improved so that
2323 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2324 limitation that in this case len(xrange(sys.maxint)) can't be
2325 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2326 work fine as long as the index i doesn't actually reach 2**31.
2327 (Python uses regular ints for sequence and string indices; fixing
2328 that is much more work.)
2329
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002330- Two changes to from...import:
2331
Guido van Rossumba381232001-02-03 15:06:40 +00002332 1) "from M import X" now works even if (after loading module M)
2333 sys.modules['M'] is not a real module; it's basically a getattr()
2334 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002335
2336 2) "from M import *" now looks for M.__all__ to decide which names to
2337 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2338 filters out names starting with '_' as before. Whether or not
2339 __all__ exists, there's no restriction on the type of M.
2340
Guido van Rossumf61f1662001-01-10 20:13:55 +00002341- File objects have a new method, xreadlines(). This is the fastest
2342 way to iterate over all lines in a file:
2343
2344 for line in file.xreadlines():
2345 ...do something to line...
2346
2347 See the xreadlines module (mentioned below) for how to do this for
2348 other file-like objects.
2349
2350- Even if you don't use file.xreadlines(), you may expect a speedup on
2351 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002352 quite a bit in platform-specific ways: on systems (like Linux) that
2353 support flockfile(), getc_unlocked(), and funlockfile(), those are
2354 used by default. On systems (like Windows) without getc_unlocked(),
2355 a complicated (but still thread-safe) method using fgets() is used by
2356 default.
2357
Tim Petersd52269b2001-01-25 06:23:18 +00002358 You can force use of the fgets() method by #define'ing
2359 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002360 getc_unlocked()).
2361
Tim Petersd52269b2001-01-25 06:23:18 +00002362 You can force fgets() not to be used by #define'ing
2363 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002364 test_bufio.py fails -- and let us know if it does!).
2365
2366- In addition, the fileinput module, while still slower than the other
2367 methods on most platforms, has been sped up too, by using
2368 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002369
2370- Support for run-time warnings has been added, including a new
2371 command line option (-W) to specify the disposition of warnings.
2372 See the description of the warnings module below.
2373
2374- Extensive changes have been made to the coercion code. This mostly
2375 affects extension modules (which can now implement mixed-type
2376 numerical operators without having to use coercion), but
2377 occasionally, in boundary cases the coercion semantics have changed
2378 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002379 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002380 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002381 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002382
Guido van Rossumf98eda02001-01-17 15:54:45 +00002383- In connection with the coercion changes, a new built-in singleton
2384 object, NotImplemented is defined. This can be returned for
2385 operations that wish to indicate they are not implemented for a
2386 particular combination of arguments. From C, this is
2387 Py_NotImplemented.
2388
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002389- The interpreter accepts now bytecode files on the command line even
2390 if they do not have a .pyc or .pyo extension. On Linux, after executing
2391
Martin v. Löwise214baa2001-02-04 22:37:56 +00002392import imp,sys,string
2393magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2394reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2395open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002396
2397 any byte code file can be used as an executable (i.e. as an argument
2398 to execve(2)).
2399
Tim Peters9940b802000-12-01 07:59:35 +00002400- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002401 character. In 1.6 and earlier, they never produced a sign,
2402 and raised an error if the value of the long was too large
2403 to fit in a Python int. In 2.0, they produced a sign if and
2404 only if too large to fit in an int. This was inconsistent
2405 across platforms (because the size of an int varies across
2406 platforms), and inconsistent with hex() and oct(). Example:
2407
2408 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002409 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002410 'ffffffbe' # in 2.0 and before, on 32-bit machines
2411 >>> hex(-0x42L)
2412 '-0x42L' # in all versions of Python
2413
Tim Peters9940b802000-12-01 07:59:35 +00002414 The behavior of %d formats for negative Python longs remains
2415 the same as in 2.0 (although in 1.6 and before, they raised
2416 an error if the long didn't fit in a Python int).
2417
2418 %u formats don't make sense for Python longs, but are allowed
2419 and treated the same as %d in 2.1. In 2.0, a negative long
2420 formatted via %u produced a sign if and only if too large to
2421 fit in an int. In 1.6 and earlier, a negative long formatted
2422 via %u raised an error if it was too big to fit in an int.
2423
Guido van Rossum3661d392000-12-12 22:10:31 +00002424- Dictionary objects have an odd new method, popitem(). This removes
2425 an arbitrary item from the dictionary and returns it (in the form of
2426 a (key, value) pair). This can be useful for algorithms that use a
2427 dictionary as a bag of "to do" items and repeatedly need to pick one
2428 item. Such algorithms normally end up running in quadratic time;
2429 using popitem() they can usually be made to run in linear time.
2430
Tim Peters36cdad12000-12-29 02:06:45 +00002431Standard library
2432
Thomas Woutersfe385252001-01-19 23:16:56 +00002433- In the time module, the time argument to the functions strftime,
2434 localtime, gmtime, asctime and ctime is now optional, defaulting to
2435 the current time (in the local timezone).
2436
Guido van Rossumda91f222001-01-15 16:36:08 +00002437- The ftplib module now defaults to passive mode, which is deemed a
2438 more useful default given that clients are often inside firewalls
2439 these days. Note that this could break if ftplib is used to connect
2440 to a *server* that is inside a firewall, from outside; this is
2441 expected to be a very rare situation. To fix that, you can call
2442 ftp.set_pasv(0).
2443
Martin v. Löwis10a27872001-01-13 09:54:41 +00002444- The module site now treats .pth files not only for path configuration,
2445 but also supports extensions to the initialization code: Lines starting
2446 with import are executed.
2447
Guido van Rossumf61f1662001-01-10 20:13:55 +00002448- There's a new module, warnings, which implements a mechanism for
2449 issuing and filtering warnings. There are some new built-in
2450 exceptions that serve as warning categories, and a new command line
2451 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2452 turns warnings into errors). warnings.warn(message[, category])
2453 issues a warning message; this can also be called from C as
2454 PyErr_Warn(category, message).
2455
2456- A new module xreadlines was added. This exports a single factory
2457 function, xreadlines(). The intention is that this code is the
2458 absolutely fastest way to iterate over all lines in an open
2459 file(-like) object:
2460
2461 import xreadlines
2462 for line in xreadlines.xreadlines(file):
2463 ...do something to line...
2464
2465 This is equivalent to the previous the speed record holder using
2466 file.readlines(sizehint). Note that if file is a real file object
2467 (as opposed to a file-like object), this is equivalent:
2468
2469 for line in file.xreadlines():
2470 ...do something to line...
2471
Tim Peters36cdad12000-12-29 02:06:45 +00002472- The bisect module has new functions bisect_left, insort_left,
2473 bisect_right and insort_right. The old names bisect and insort
2474 are now aliases for bisect_right and insort_right. XXX_right
2475 and XXX_left methods differ in what happens when the new element
2476 compares equal to one or more elements already in the list: the
2477 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002478 right. Code that doesn't care where equal elements end up should
2479 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002480
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002481- The new curses.panel module wraps the panel library that forms part
2482 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2483
Guido van Rossumf61f1662001-01-10 20:13:55 +00002484- The SocketServer module now sets the allow_reuse_address flag by
2485 default in the TCPServer class.
2486
2487- A new function, sys._getframe(), returns the stack frame pointer of
2488 the caller. This is intended only as a building block for
2489 higher-level mechanisms such as string interpolation.
2490
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002491- The pyexpat module supports a number of new handlers, which are
2492 available only in expat 1.2. If invocation of a callback fails, it
2493 will report an additional frame in the traceback. Parser objects
2494 participate now in garbage collection. If expat reports an unknown
2495 encoding, pyexpat will try to use a Python codec; that works only
2496 for single-byte charsets. The parser type objects is exposed as
2497 XMLParserObject.
2498
2499- xml.dom now offers standard definitions for symbolic node type and
2500 exception code constants, and a hierarchy of DOM exceptions. minidom
2501 was adjusted to use them.
2502
2503- The conformance of xml.dom.minidom to the DOM specification was
2504 improved. It detects a number of additional error cases; the
2505 previous/next relationship works even when the tree is modified;
2506 Node supports the normalize() method; NamedNodeMap, DocumentType and
2507 DOMImplementation classes were added; Element supports the
2508 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2509 method.
2510
Guido van Rossumf61f1662001-01-10 20:13:55 +00002511Build issues
2512
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002513- For Unix (and Unix-compatible) builds, configuration and building of
2514 extension modules is now greatly automated. Rather than having to
2515 edit the Modules/Setup file to indicate which modules should be
2516 built and where their include files and libraries are, a
2517 distutils-based setup.py script now takes care of building most
2518 extension modules. All extension modules built this way are built
2519 as shared libraries. Only a few modules that must be linked
2520 statically are still listed in the Setup file; you won't need to
2521 edit their configuration.
2522
2523- Python should now build out of the box on Cygwin. If it doesn't,
2524 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002525
2526- Python now always uses its own (renamed) implementation of getopt()
2527 -- there's too much variation among C library getopt()
2528 implementations.
2529
2530- C++ compilers are better supported; the CXX macro is always set to a
2531 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002532
Tim Petersd92dfe02000-12-12 01:18:41 +00002533Windows changes
2534
2535- select module: By default under Windows, a select() call
2536 can specify no more than 64 sockets. Python now boosts
2537 this Microsoft default to 512. If you need even more than
2538 that, see the MS docs (you'll need to #define FD_SETSIZE
2539 and recompile Python from source).
2540
Guido van Rossumf61f1662001-01-10 20:13:55 +00002541- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2542 subdirectory is no more!
2543
Tim Petersa3a3a032000-11-30 05:22:44 +00002544
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002545What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002546=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002547
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002548Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002549changes are in the file HISTORY. If you are making the jump directly
2550from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2551HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002552
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002553Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2554the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2555http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002556
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002557--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002558
2559======================================================================
2560
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002561What's new in 2.0 (since release candidate 1)?
2562==============================================
2563
2564Standard library
2565
2566- The copy_reg module was modified to clarify its intended use: to
2567 register pickle support for extension types, not for classes.
2568 pickle() will raise a TypeError if it is passed a class.
2569
2570- Fixed a bug in gettext's "normalize and expand" code that prevented
2571 it from finding an existing .mo file.
2572
2573- Restored support for HTTP/0.9 servers in httplib.
2574
Tim Peters989b7b92000-10-16 20:24:53 +00002575- The math module was changed to stop raising OverflowError in case of
2576 underflow, and return 0 instead in underflow cases. Whether Python
2577 used to raise OverflowError in case of underflow was platform-
2578 dependent (it did when the platform math library set errno to ERANGE
2579 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002580
2581- Fixed a bug in StringIO that occurred when the file position was not
2582 at the end of the file and write() was called with enough data to
2583 extend past the end of the file.
2584
2585- Fixed a bug that caused Tkinter error messages to get lost on
2586 Windows. The bug was fixed by replacing direct use of
2587 interp->result with Tcl_GetStringResult(interp).
2588
2589- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2590 redirect response.
2591
2592- Several changes were made to distutils: Some debugging code was
2593 removed from util. Fixed the installer used when an external zip
2594 program (like WinZip) is not found; the source code for this
2595 installer is in Misc/distutils. check_lib() was modified to behave
2596 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2597 test for whether installed modules are on sys.path was changed to
2598 use both normcase() and normpath().
2599
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002600- Several minor bugs were fixed in the xml package (the minidom,
2601 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002602
2603- The regression test driver (regrtest.py) behavior when invoked with
2604 -l changed: It now reports a count of objects that are recognized as
2605 garbage but not freed by the garbage collector.
2606
Tim Peters989b7b92000-10-16 20:24:53 +00002607- The regression test for the math module was changed to test
2608 exceptional behavior when the test is run in verbose mode. Python
2609 cannot yet guarantee consistent exception behavior across platforms,
2610 so the exception part of test_math is run only in verbose mode, and
2611 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002612
2613Internals
2614
2615- PyOS_CheckStack() has been disabled on Win64, where it caused
2616 test_sre to fail.
2617
2618Build issues
2619
2620- Changed compiler flags, so that gcc is always invoked with -Wall and
2621 -Wstrict-prototypes. Users compiling Python with GCC should see
2622 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002623 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002624 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002625
Tim Petersa3a3a032000-11-30 05:22:44 +00002626- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002627
2628Tools and other miscellany
2629
2630- The compiler in Tools/compiler was updated to support the new
2631 language features introduced in 2.0: extended print statement, list
2632 comprehensions, and augmented assignments. The new compiler should
2633 also be backwards compatible with Python 1.5.2; the compiler will
2634 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002635 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002636
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002637What's new in 2.0 release candidate 1 (since beta 2)?
2638=====================================================
2639
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002640What is release candidate 1?
2641
2642We believe that release candidate 1 will fix all known bugs that we
2643intend to fix for the 2.0 final release. This release should be a bit
2644more stable than the previous betas. We would like to see even more
2645widespread testing before the final release, so we are producing this
2646release candidate. The final release will be exactly the same unless
2647any show-stopping (or brown bag) bugs are found by testers of the
2648release candidate.
2649
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002650All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002651to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002652
2653Core language, builtins, and interpreter
2654
2655- A bug that caused crashes when __coerce__ was used with augmented
2656 assignment, e.g. +=, was fixed.
2657
2658- Raise ZeroDivisionError when raising zero to a negative number,
2659 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2660 power operator and the result of math.pow(0.0, -2.0) will vary by
2661 platform. On Linux, it raises a ValueError.
2662
2663- A bug in Unicode string interpolation was fixed that occasionally
2664 caused errors with formats including "%%". For example, the
2665 following expression "%% %s" % u"abc" no longer raises a TypeError.
2666
2667- Compilation of deeply nested expressions raises MemoryError instead
2668 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2669
2670- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2671 rendering them useless. They are now written in binary mode again.
2672
2673Standard library
2674
2675- Keyword arguments are now accepted for most pattern and match object
2676 methods in SRE, the standard regular expression engine.
2677
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002678- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002679 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002680
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002681- Several bugs in the Unicode handling and error handling in _tkinter
2682 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002683
2684- Fix memory management errors in Merge() and Tkapp_Call() routines.
2685
2686- Several changes were made to cStringIO to make it compatible with
2687 the file-like object interface and with StringIO. If operations are
2688 performed on a closed object, an exception is raised. The truncate
2689 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002690 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002691
2692- There were many changes made to the linuxaudiodev module and its
2693 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002694 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002695
2696 Note that this module is named poorly, because it should work
2697 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002698 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002699
2700 The module now raises exceptions when errors occur instead of
2701 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2702 audio) and defines a getptr() method that calls the
2703 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2704
2705- The library_version attribute, introduced in an earlier beta, was
2706 removed because it can not be supported with early versions of the C
2707 readline library, which provides no way to determine the version at
2708 compile-time.
2709
2710- The binascii module is now enabled on Win64.
2711
Tim Peters46446d62000-10-09 21:19:31 +00002712- tokenize.py no longer suffers "recursion depth" errors when parsing
2713 programs with very long string literals.
2714
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002715Internals
2716
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002717- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002718 which is called when the interpreter starts up to determine where
2719 the standard library is installed. These vulnerabilities affect all
2720 previous versions of Python and can be exploited by setting very
2721 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2722 setuid Python script, although use of the wrapper in
2723 Misc/setuid-prog.c will eliminate the vulnerability.
2724
2725- Fixed garbage collection bugs in instance creation that were
2726 triggered when errors occurred during initialization. The solution,
2727 applied in cPickle and in PyInstance_New(), is to call
2728 PyObject_GC_Init() after the initialization of the object's
2729 container attributes is complete.
2730
2731- pyexpat adds definitions of PyModule_AddStringConstant and
2732 PyModule_AddObject if the Python version is less than 2.0, which
2733 provides compatibility with PyXML on Python 1.5.2.
2734
2735- If the platform has a bogus definition for LONG_BIT (the number of
2736 bits in a long), an error will be reported at compile time.
2737
2738- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2739 collection crashes and possibly other, unreported crashes.
2740
2741- Fixed a memory leak in _PyUnicode_Fini().
2742
2743Build issues
2744
2745- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002746 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002747 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002748
2749- The mmap.PAGESIZE constant is now initialized using sysconf when
2750 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2751
2752- The md5 file should now compile on all platforms.
2753
2754- The select module now compiles on platforms that do not define
2755 POLLRDNORM and related constants.
2756
2757- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002758 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002759
Jeremy Hylton10921202000-10-09 18:34:12 +00002760- BeOS: A number of changes were made to the build and installation
2761 process. ar-fake now operates on a directory of object files.
2762 dl_export.h is gone, and its macros now appear on the mwcc command
2763 line during build on PPC BeOS.
2764
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002765- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002766 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002767
2768- Cygwin: Support for shared libraries, Tkinter, and sockets.
2769
2770- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2771
2772Tools and other miscellany
2773
2774- Removed debugging prints from main used with freeze.
2775
Tim Peters46446d62000-10-09 21:19:31 +00002776- IDLE auto-indent no longer crashes when it encounters Unicode
2777 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002778
2779What's new in 2.0 beta 2 (since beta 1)?
2780========================================
2781
2782Core language, builtins, and interpreter
2783
Tim Peters482c0212000-09-26 06:33:09 +00002784- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002785 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002786
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002787- Add -h and -V command line options to print the usage message and
2788 Python version number and exit immediately.
2789
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002790- eval() and exec accept Unicode objects as code parameters.
2791
2792- getattr() and setattr() now also accept Unicode objects for the
2793 attribute name, which are converted to strings using the default
2794 encoding before lookup.
2795
2796- Multiplication on string and Unicode now does proper bounds
2797 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2798 string is too long."
2799
2800- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002801 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002802
Jeremy Hylton1b618592000-09-26 05:32:36 +00002803
2804Standard library and extensions
2805
Guido van Rossum5b08f132001-04-16 02:05:23 +00002806- socket module: the OpenSSL code now adds support for RAND_status()
2807 and EGD (Entropy Gathering Device).
2808
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002809- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002810 argument checking; it still takes no arguments.
2811
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002812- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002813
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002814- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002815
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002816- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002817
2818- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002819 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002820
2821- copy: Copy Unicode objects atomically.
2822
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002823- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002824
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002825- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002826
Fred Drake67233bc2000-09-26 16:40:27 +00002827- dbm: Add get() and setdefault() methods to dbm object. Add constant
2828 `library' to module that names the library used. Added doc strings
2829 and method names to error messages. Uses configure to determine
2830 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2831 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002832
2833- distutils: Update to version 0.9.3.
2834
2835- dl: Add several dl.RTLD_ constants.
2836
2837- fpectl: Now supported on FreeBSD.
2838
2839- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2840 found by the collector will be saved in gc.garbage. This is useful
2841 for debugging a program that creates reference cycles.
2842
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002843- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002844 of HTTP class. Do not close socket on zero-length response. Do not
2845 crash when server sends invalid content-length header.
2846
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002847- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002848
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002849- marshal: When reading a short, sign-extend on platforms where shorts
2850 are bigger than 16 bits. When reading a long, repair the unportable
2851 sign extension that was being done for 64-bit machines. (It assumed
2852 that signed right shift sign-extends.)
2853
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002854- operator: Add contains(), invert(), __invert__() as aliases for
2855 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002856
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002857- os: Add support for popen2() and popen3() on all platforms where
2858 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002859
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002860- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002861 clicking on a file in Explorer (or passing the file name to the
2862 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002863
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002864- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002865 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002866
2867- pickle: Now raises ValueError when an invalid pickle that contains
2868 a non-string repr where a string repr was expected. This behavior
2869 matches cPickle.
2870
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002871- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002872
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002873- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002874
2875- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002876 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002877 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002878
2879- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002880 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002881
2882- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002883 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002884 few cycles during startup since the first call to
2885 setdefaultencoding() will initialize the codec registry and the
2886 encodings package.
2887
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002888- socket: Support for size hint in readlines() method of object returned
2889 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002890
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002891- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002892 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002893 is followed by whitespace.
2894
Tim Petersa3a3a032000-11-30 05:22:44 +00002895- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002896
2897- struct: Check ranges for bytes and shorts.
2898
2899- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002900 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002901
2902- Tkinter: Image objects are now guaranteed to have unique ids. Set
2903 event.delta to zero if Tk version doesn't support mousewheel.
2904 Removed some debugging prints.
2905
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002906- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002907
Fred Drake67233bc2000-09-26 16:40:27 +00002908- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002909 which works around a bug in Norton AntiVirus 2000 that leads directly
2910 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002911
2912- xml: New version detection code allows PyXML to override standard
2913 XML package if PyXML version is greater than 0.6.1.
2914
Fred Drake64bb3802000-09-26 16:21:35 +00002915- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2916 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2917 tree only for nodes which are sufficiently interesting to a specific
2918 application. Does not provide the HTML-specific extensions. Still
2919 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002920
Fred Drake64bb3802000-09-26 16:21:35 +00002921- xml.sax: SAX 2 support for Python, including all the handler
2922 interfaces needed to process XML 1.0 compliant XML. Some
2923 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002924
Fred Drake64bb3802000-09-26 16:21:35 +00002925- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2926 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002927
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002928
Jeremy Hylton1b618592000-09-26 05:32:36 +00002929C API
2930
2931- Add three new convenience functions for module initialization --
2932 PyModule_AddObject(), PyModule_AddIntConstant(), and
2933 PyModule_AddStringConstant().
2934
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002935- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002936 removed and add #error to Python.h if NULL isn't defined after
2937 #include of stdio.h.
2938
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002939- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002940 backwards compatibility (at the source level) with old extensions.
2941
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002942- A wrapper API was added for signal() and sigaction(). Instead of
2943 either function, always use PyOS_getsig() to get a signal handler
2944 and PyOS_setsig() to set one. A new convenience typedef
2945 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002946
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002947- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002948 internal data buffer and size of a string object -- or the default
2949 encoded version of a Unicode object.
2950
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002951- PyString_Size() and PyString_AsString() accept Unicode objects.
2952
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002953- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002954 exists). INT_MAX and LONG_MAX will always be defined, even if
2955 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002956
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002957- PyFloat_FromString takes a second argument, pend, that was
2958 effectively useless. It is now officially useless but preserved for
2959 backwards compatibility. If the pend argument is not NULL, *pend is
2960 set to NULL.
2961
2962- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2963 for the attribute name. See note on getattr() above.
2964
2965- A few bug fixes to argument processing for Unicode.
2966 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2967 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2968 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002969 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002970
2971- Py_BuildValue accepts B format (for bgen-generated code).
2972
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002973
Jeremy Hylton1b618592000-09-26 05:32:36 +00002974Internals
2975
2976- On Unix, fix code for finding Python installation directory so that
2977 it works when argv[0] is a relative path.
2978
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002979- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002980 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002981 rather than by generating a copy of the object.
2982
Tim Peters482c0212000-09-26 06:33:09 +00002983- Several of the internal Unicode tables are much smaller now, and
2984 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002985
Jeremy Hylton97693b02000-09-26 17:42:51 +00002986- In the garbage collector: Fixed bug in collection of tuples. Fixed
2987 bug that caused some instances to be removed from the container set
2988 while they were still live. Fixed parsing in gc.set_debug() for
2989 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002990
2991- Fixed refcount problem in instance deallocation that only occurred
2992 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2993
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002994- On Windows, getpythonregpath is now protected against null data in
2995 registry key.
2996
2997- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002998 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002999
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003000
Jeremy Hylton1b618592000-09-26 05:32:36 +00003001Build and platform-specific issues
3002
3003- Better support of GNU Pth via --with-pth configure option.
3004
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003005- Python/C API now properly exposed to dynamically-loaded extension
3006 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003007
3008- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3009 Don't define MS_SYNC to be zero when it is undefined. Added missing
3010 prototypes in posixmodule.c.
3011
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003012- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003013 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003014
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003015- Fix largefile support on older NetBSD systems and OpenBSD by adding
3016 define for TELL64.
3017
3018
3019Tools and other miscellany
3020
3021- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3022
3023- freeze: The modulefinder now works with 2.0 opcodes.
3024
Tim Petersa3a3a032000-11-30 05:22:44 +00003025- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003026 Move hackery of sys.argv until after the Tk instance has been
3027 created, which allows the application-specific Tkinter
3028 initialization to be executed if present; also pass an explicit
3029 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003030
Jeremy Hylton1b618592000-09-26 05:32:36 +00003031
3032What's new in 2.0 beta 1?
3033=========================
3034
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003035Source Incompatibilities
3036------------------------
3037
3038None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3039such as single-argument append(), connect() and bind(), and changes to
3040str(long) and repr(float).
3041
3042
3043Binary Incompatibilities
3044------------------------
3045
3046- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3047with Python 2.0; these extensions will have to be rebuilt for Python
30482.0.
3049
3050- On Windows, attempting to import a third party extension built for
3051Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3052can do about this. Check your PYTHONPATH environment variable!
3053
3054- Python bytecode files (*.pyc and *.pyo) are not compatible between
3055releases.
3056
3057
3058Overview of Changes Since 1.6
3059-----------------------------
3060
3061There are many new modules (including brand new XML support through
3062the xml package, and i18n support through the gettext module); a list
3063of all new modules is included below. Lots of bugs have been fixed.
3064
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003065The process for making major new changes to the language has changed
3066since Python 1.6. Enhancements must now be documented by a Python
3067Enhancement Proposal (PEP) before they can be accepted.
3068
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003069There are several important syntax enhancements, described in more
3070detail below:
3071
3072 - Augmented assignment, e.g. x += 1
3073
3074 - List comprehensions, e.g. [x**2 for x in range(10)]
3075
3076 - Extended import statement, e.g. import Module as Name
3077
3078 - Extended print statement, e.g. print >> file, "Hello"
3079
3080Other important changes:
3081
3082 - Optional collection of cyclical garbage
3083
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003084Python Enhancement Proposal (PEP)
3085---------------------------------
3086
3087PEP stands for Python Enhancement Proposal. A PEP is a design
3088document providing information to the Python community, or describing
3089a new feature for Python. The PEP should provide a concise technical
3090specification of the feature and a rationale for the feature.
3091
3092We intend PEPs to be the primary mechanisms for proposing new
3093features, for collecting community input on an issue, and for
3094documenting the design decisions that have gone into Python. The PEP
3095author is responsible for building consensus within the community and
3096documenting dissenting opinions.
3097
3098The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003099
3100Augmented Assignment
3101--------------------
3102
3103This must have been the most-requested feature of the past years!
3104Eleven new assignment operators were added:
3105
Guido van Rossume905e952000-09-05 12:42:46 +00003106 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003107
3108For example,
3109
3110 A += B
3111
3112is similar to
3113
3114 A = A + B
3115
3116except that A is evaluated only once (relevant when A is something
3117like dict[index].attr).
3118
3119However, if A is a mutable object, A may be modified in place. Thus,
3120if A is a number or a string, A += B has the same effect as A = A+B
3121(except A is only evaluated once); but if a is a list, A += B has the
3122same effect as A.extend(B)!
3123
3124Classes and built-in object types can override the new operators in
3125order to implement the in-place behavior; the not-in-place behavior is
3126used automatically as a fallback when an object doesn't implement the
3127in-place behavior. For classes, the method name is derived from the
3128method name for the corresponding not-in-place operator by inserting
3129an 'i' in front of the name, e.g. __iadd__ implements in-place
3130__add__.
3131
3132Augmented assignment was implemented by Thomas Wouters.
3133
3134
3135List Comprehensions
3136-------------------
3137
3138This is a flexible new notation for lists whose elements are computed
3139from another list (or lists). The simplest form is:
3140
3141 [<expression> for <variable> in <sequence>]
3142
Guido van Rossum56db0952000-09-06 23:34:25 +00003143For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003144This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003145
3146You can also add a condition:
3147
3148 [<expression> for <variable> in <sequence> if <condition>]
3149
3150For example, [w for w in words if w == w.lower()] would yield the list
3151of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003152than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003153
3154You can also have nested for loops and more than one 'if' clause. For
3155example, here's a function that flattens a sequence of sequences::
3156
3157 def flatten(seq):
3158 return [x for subseq in seq for x in subseq]
3159
3160 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3161
3162This prints
3163
3164 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3165
3166List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003167Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003168
3169
3170Extended Import Statement
3171-------------------------
3172
3173Many people have asked for a way to import a module under a different
3174name. This can be accomplished like this:
3175
3176 import foo
3177 bar = foo
3178 del foo
3179
3180but this common idiom gets old quickly. A simple extension of the
3181import statement now allows this to be written as follows:
3182
3183 import foo as bar
3184
3185There's also a variant for 'from ... import':
3186
3187 from foo import bar as spam
3188
3189This also works with packages; e.g. you can write this:
3190
3191 import test.regrtest as regrtest
3192
3193Note that 'as' is not a new keyword -- it is recognized only in this
3194context (this is only possible because the syntax for the import
3195statement doesn't involve expressions).
3196
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003197Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003198
3199
3200Extended Print Statement
3201------------------------
3202
3203Easily the most controversial new feature, this extension to the print
3204statement adds an option to make the output go to a different file
3205than the default sys.stdout.
3206
3207For example, to write an error message to sys.stderr, you can now
3208write:
3209
3210 print >> sys.stderr, "Error: bad dog!"
3211
3212As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003213evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003214
3215 print >> None, "Hello world"
3216
3217is equivalent to
3218
3219 print "Hello world"
3220
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003221Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003222
3223
3224Optional Collection of Cyclical Garbage
3225---------------------------------------
3226
3227Python is now equipped with a garbage collector that can hunt down
3228cyclical references between Python objects. It's no replacement for
3229reference counting; in fact, it depends on the reference counts being
3230correct, and decides that a set of objects belong to a cycle if all
3231their reference counts can be accounted for from their references to
3232each other. This devious scheme was first proposed by Eric Tiedemann,
3233and brought to implementation by Neil Schemenauer.
3234
3235There's a module "gc" that lets you control some parameters of the
3236garbage collection. There's also an option to the configure script
3237that lets you enable or disable the garbage collection. In 2.0b1,
3238it's on by default, so that we (hopefully) can collect decent user
3239experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003240performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003241off by default in the final 2.0 release.
3242
3243
3244Smaller Changes
3245---------------
3246
3247A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3248map(None, seq1, seq2, ...) when the sequences have the same length;
3249i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3250the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003251zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003252
3253sys.version_info is a tuple (major, minor, micro, level, serial).
3254
3255Dictionaries have an odd new method, setdefault(key, default).
3256dict.setdefault(key, default) returns dict[key] if it exists; if not,
3257it sets dict[key] to default and returns that value. Thus:
3258
3259 dict.setdefault(key, []).append(item)
3260
3261does the same work as this common idiom:
3262
3263 if not dict.has_key(key):
3264 dict[key] = []
3265 dict[key].append(item)
3266
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003267There are two new variants of SyntaxError that are raised for
3268indentation-related errors: IndentationError and TabError.
3269
3270Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3271escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003272
3273The limits on the size of expressions and file in Python source code
3274have been raised from 2**16 to 2**32. Previous versions of Python
3275were limited because the maximum argument size the Python VM accepted
3276was 2**16. This limited the size of object constructor expressions,
3277e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3278limit was raised thanks to a patch by Charles Waldman that effectively
3279fixes the problem. It is now much more likely that you will be
3280limited by available memory than by an arbitrary limit in Python.
3281
3282The interpreter's maximum recursion depth can be modified by Python
3283programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3284limit is the maximum number of recursive calls that can be made by
3285Python code. The limit exists to prevent infinite recursion from
3286overflowing the C stack and causing a core dump. The default value is
32871000. The maximum safe value for a particular platform can be found
3288by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003289
3290New Modules and Packages
3291------------------------
3292
3293atexit - for registering functions to be called when Python exits.
3294
3295imputil - Greg Stein's alternative API for writing custom import
3296hooks.
3297
3298pyexpat - an interface to the Expat XML parser, contributed by Paul
3299Prescod.
3300
3301xml - a new package with XML support code organized (so far) in three
3302subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3303would fill a volume. There's a special feature whereby a
3304user-installed package named _xmlplus overrides the standard
3305xmlpackage; this is intended to give the XML SIG a hook to distribute
3306backwards-compatible updates to the standard xml package.
3307
3308webbrowser - a platform-independent API to launch a web browser.
3309
3310
Guido van Rossume905e952000-09-05 12:42:46 +00003311Changed Modules
3312---------------
3313
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003314array -- new methods for array objects: count, extend, index, pop, and
3315remove
3316
3317binascii -- new functions b2a_hex and a2b_hex that convert between
3318binary data and its hex representation
3319
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003320calendar -- Many new functions that support features including control
3321over which day of the week is the first day, returning strings instead
3322of printing them. Also new symbolic constants for days of week,
3323e.g. MONDAY, ..., SUNDAY.
3324
3325cgi -- FieldStorage objects have a getvalue method that works like a
3326dictionary's get method and returns the value attribute of the object.
3327
3328ConfigParser -- The parser object has new methods has_option,
3329remove_section, remove_option, set, and write. They allow the module
3330to be used for writing config files as well as reading them.
3331
3332ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003333optionally support the RFC 959 REST command.
3334
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003335gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003336
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003337httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3338the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003339
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003340locale -- implement getdefaultlocale for Win32 and Macintosh
3341
3342marshal -- no longer dumps core when marshaling deeply nested or
3343recursive data structures
3344
3345os -- new functions isatty, seteuid, setegid, setreuid, setregid
3346
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003347os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3348support under Unix.
3349
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003350os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003351
3352os.path -- fix semantics of os.path.commonprefix
3353
3354smtplib -- support for sending very long messages
3355
3356socket -- new function getfqdn()
3357
3358readline -- new functions to read, write and truncate history files.
3359The readline section of the library reference manual contains an
3360example.
3361
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003362select -- add interface to poll system call
3363
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003364shutil -- new copyfileobj function
3365
3366SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3367HTTP server.
3368
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003369Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003370
3371urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003372e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003373
3374whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003375
3376
3377Obsolete Modules
3378----------------
3379
3380None. However note that 1.6 made a whole slew of modules obsolete:
3381stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3382poly, zmod, strop, util, whatsound.
3383
3384
3385Changed, New, Obsolete Tools
3386----------------------------
3387
Tim Peters8b092332000-09-05 20:15:25 +00003388None.
Guido van Rossume905e952000-09-05 12:42:46 +00003389
3390
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003391C-level Changes
3392---------------
3393
3394Several cleanup jobs were carried out throughout the source code.
3395
3396All C code was converted to ANSI C; we got rid of all uses of the
3397Py_PROTO() macro, which makes the header files a lot more readable.
3398
3399Most of the portability hacks were moved to a new header file,
3400pyport.h; several other new header files were added and some old
3401header files were removed, in an attempt to create a more rational set
3402of header files. (Few of these ever need to be included explicitly;
3403they are all included by Python.h.)
3404
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003405Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003406and Win64, especially for the new Intel Itanium processor. Mick also
3407added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003408
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003409The C APIs to return an object's size have been update to consistently
3410use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3411previous versions, the abstract interfaces used PyXXX_Length and the
3412concrete interfaces used PyXXX_Size. The old names,
3413e.g. PyObject_Length, are still available for backwards compatibility
3414at the API level, but are deprecated.
3415
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003416The PyOS_CheckStack function has been implemented on Windows by
3417Fredrik Lundh. It prevents Python from failing with a stack overflow
3418on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003419
3420The GC changes resulted in creation of two new slots on object,
3421tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003422the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003423
3424The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003425C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003426
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003427PyErr_Format has been updated to automatically calculate the size of
3428the buffer needed to hold the formatted result string. This change
3429prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003430
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003431New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003432
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003433PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3434that are the same as their non-Ex counterparts except they take an
3435extra flag argument that tells them to close the file when done.
3436
3437XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003438
Tim Peters8b092332000-09-05 20:15:25 +00003439
3440Windows Changes
3441---------------
3442
3443New popen2/popen3/peopen4 in os module (see Changed Modules above).
3444
3445os.popen is much more usable on Windows 95 and 98. See Microsoft
3446Knowledge Base article Q150956. The Win9x workaround described there
3447is implemented by the new w9xpopen.exe helper in the root of your
3448Python installation. Note that Python uses this internally; it is not
3449a standalone program.
3450
3451Administrator privileges are no longer required to install Python
3452on Windows NT or Windows 2000. If you have administrator privileges,
3453Python's registry info will be written under HKEY_LOCAL_MACHINE.
3454Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003455under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003456uses of Python, but will prevent some advanced uses from working
3457(for example, running a Python script as an NT service, or possibly
3458from CGI).
3459
3460[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3461installer; instead, it installs the needed Tcl/Tk files directly in the
3462Python directory. If you already have a Tcl/Tk installation, this
3463wastes some disk space (about 4 Megs) but avoids problems with
3464conflicting Tcl/Tk installations, and makes it much easier for Python
3465to ensure that Tcl/Tk can find all its files.
3466
3467[This was new in 1.6] The Windows installer now installs by default in
3468\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3469
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003470
3471Updates to the changes between 1.5.2 and 1.6
3472--------------------------------------------
3473
3474The 1.6 NEWS file can't be changed after the release is done, so here
3475is some late-breaking news:
3476
3477New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3478and changes to getlocale() and setlocale().
3479
3480The new module is now enabled per default.
3481
3482It is not true that the encodings codecs cannot be used for normal
3483strings: the string.encode() (which is also present on 8-bit strings
3484!) allows using them for 8-bit strings too, e.g. to convert files from
3485cp1252 (Windows) to latin-1 or vice-versa.
3486
3487Japanese codecs are available from Tamito KAJIYAMA:
3488http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3489
3490
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003491======================================================================