blob: 5608af98a8bd885d990abca3bfab75d9a848112b [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Fred Draked0ba6362002-05-02 21:28:26 +00009- Deprecated features of xrange objects have been removed as
10 promised. The start, stop, and step attributes and the tolist()
11 method no longer exist. xrange repetition and slicing have been
12 removed.
13
Guido van Rossum7dab2422002-04-26 19:40:56 +000014- New builtin function enumerate(x), from PEP 279. Example:
15 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
16 The argument can be an arbitrary iterable object.
17
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000018- The assert statement no longer tests __debug__ at runtime. This means
19 that assert statements cannot be disabled by assigning a false value
20 to __debug__.
21
Walter Dörwald068325e2002-04-15 13:36:47 +000022- A method zfill() was added to str and unicode, that fills a numeric
23 string to the left with zeros. For example,
24 "+123".zfill(6) -> "+00123".
25
Guido van Rossum862fe3c2002-04-15 12:36:47 +000026- Complex numbers supported divmod() and the // and % operators, but
27 these make no sense. Since this was documented, they're being
28 deprecated now.
29
Guido van Rossum26dd8302002-04-26 20:11:29 +000030- String and unicode methods lstrip(), rstrip() and strip() now take
31 an optional argument that specifies the characters to strip. For
32 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000033
Guido van Rossumc69343b2002-04-12 19:22:48 +000034- Added a new dict method pop(key). This removes and returns the
35 value corresponding to key. [SF patch #539949]
36
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000037- Changed new-style class instantiation so that when C's __new__
38 method returns something that's not a C instance, its __init__ is
39 not called. [SF bug #537450]
40
Guido van Rossum181e41a2002-04-06 00:23:25 +000041- Fixed super() to work correctly with class methods. [SF bug #535444]
42
Guido van Rossum47834462002-04-04 15:21:33 +000043- A new built-in type, bool, has been added, as well as built-in
44 names for its two values, True and False. Comparisons and sundry
45 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000046 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000047 is backward compatible.
48
Guido van Rossum95b62a62002-03-29 01:07:24 +000049- Fixed two bugs reported as SF #535905: under certain conditions,
50 deallocating a deeply nested structure could cause a segfault in the
51 garbage collector, due to interaction with the "trashcan" code;
52 access to the current frame during destruction of a local variable
53 could access a pointer to freed memory.
54
Neil Schemenauer9d50d132002-03-22 17:06:59 +000055- The optional object allocator has been enabled by default.
56
Guido van Rossum8c842552002-03-14 23:05:54 +000057- If you try to pickle an instance of a class that has __slots__ but
58 doesn't define or override __getstate__, a TypeError is now raised.
59 This is done by adding a bozo __getstate__ to the class that always
60 raises TypeError. (Before, this would appear to be pickled, but the
61 state of the slots would be lost.)
62
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000063- PyErr_Display will provide file and line information for all exceptions
64 that have an attribute print_file_and_line, not just SyntaxErrors.
65
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000066- The UTF-8 codec will now encode and decode Unicode surrogates
67 correctly and without raising exceptions for unpaired ones.
68
Neal Norwitz649b7592002-01-01 19:07:13 +000069- file.xreadlines() now raises a ValueError if the file is closed:
70 Previously, an xreadlines object was returned which would raise
71 a ValueError when the xreadlines.next() method was called.
72
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000073- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +000074 An exception will now be raised if more than one argument is used.
75
Tim Petersaf8446f2001-12-21 21:36:50 +000076Extension modules
77
Tim Peters81b92512002-04-29 01:37:32 +000078- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +000079 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +000080 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +000081
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000082- posix.killpg and posix.mknod have been added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +000083
Martin v. Löwis2e64c342002-03-27 18:49:02 +000084- The locale module now exposes the C library's gettext interface.
85
Tim Petersfbf74f22002-03-14 19:06:01 +000086- A security hole ("double free") was found in zlib-1.1.3, a popular
87 third party compression library used by some Python modules. The
88 hole was quickly plugged in zlib-1.1.4, and the Windows build of
89 Python now ships with zlib-1.1.4.
90
Martin v. Löwis688357e2002-04-08 21:28:20 +000091- pwd, grp, and resource return enhanced tuples now, with symbolic
92 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +000093
Martin v. Löwis99866332002-03-01 10:27:01 +000094- array.array is now a type object. A new format character
95 'u' indicates Py_UNICODE arrays. For those, .tounicode and
96 .fromunicode methods are available. Arrays now support __iadd__
97 and __imul__.
98
Neal Norwitze790eae2002-01-01 21:14:12 +000099- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000100 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
101 is called.
102
Tim Petersaf8446f2001-12-21 21:36:50 +0000103Library
104
Tim Peters46c04e12002-05-05 20:40:00 +0000105- random.gauss() uses a piece of hidden state used by nothing else,
106 and the .seed() and .whseed() methods failed to reset it. In other
107 words, setting the seed didn't completely determine the sequence of
108 results produced by random.gauss(). It does now. Programs repeatedly
109 mixing calls to a seed method with calls to gauss() may see different
110 results now.
111
Fred Drake7f781c92002-05-01 20:33:53 +0000112- The pickle.Pickler class grew a clear_memo() method to mimic that
113 provided by cPickle.Pickler.
114
Tim Peters81b92512002-04-29 01:37:32 +0000115- difflib's SequenceMatcher class now does a dynamic analysis of
116 which elements are so frequent as to constitute noise. For
117 comparing files as sequences of lines, this generally works better
118 than the IS_LINE_JUNK function, and function ndiff's linejunk
119 argument defaults to None now as a result. A happy benefit is
120 that SequenceMatcher may run much faster now when applied
121 to large files with many duplicate lines (for example, C program
122 text with lots of repeated "}" and "return NULL;" lines).
123
Guido van Rossum256705b2002-04-23 13:29:43 +0000124- New Text.dump() method in Tkinter module.
125
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000126- New distutils commands for building packagers were added to
127 support pkgtool on Solaris and swinstall on HP-UX.
128
129- distutils now has a new abstract binary packager base class
130 command/bdist_packager, which simplifies writing packagers.
131 This will hopefully provide the missing bits to encourage
132 people to submit more packagers, e.g. for Debian, FreeBSD
133 and other systems.
134
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000135- The UTF-16, -LE and -BE now raise a NotImplementedError
136 for all calls to .readline(). Previously, they used to just
137 produce garbage or fail with an encoding error -- UTF-16 is
138 a 2-byte encoding and the C lib's line reading APIs don't
139 work well with these.
140
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000141- compileall now supports quiet operation.
142
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000143- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000144 connections.
145
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000146- socket module: the SSL support was broken out of the main
147 _socket module C helper and placed into a new _ssl helper
148 which now gets imported by socket.py if available and working.
149
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000150- encodings package: added aliases for all supported IANA character
151 sets
152
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000153- ftplib: to safeguard the user's privacy, anonymous login will use
154 "anonymous@" as default password, rather than the real user and host
155 name.
156
Fred Drake36736122002-01-10 13:50:31 +0000157- webbrowser: tightened up the command passed to os.system() so that
158 arbitrary shell code can't be executed because a bogus URL was
159 passed in.
160
Tim Peters11bd9942002-02-01 00:52:29 +0000161- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000162 gettext.find an optional all argument. Translations will now fallback
163 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000164
Martin v. Löwis9668b932002-01-12 11:27:42 +0000165- distutils bdist commands now offer a --skip-build option.
166
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000167- warnings.warn now accepts a Warning instance as first argument.
168
Fred Drakefed7e852002-04-04 19:36:15 +0000169- The xml.sax.expatreader.ExpatParser class will no longer create
170 circular references by using itself as the locator that gets passed
171 to the content handler implementation. [SF bug #535474]
172
Tim Petersaf8446f2001-12-21 21:36:50 +0000173Tools/Demos
174
Marc-André Lemburg46260092002-04-04 16:17:11 +0000175- freeze.py now produces binaries which can import shared modules,
176 unlike before when this failed due to missing symbol exports in
177 the generated binary.
178
Tim Petersaf8446f2001-12-21 21:36:50 +0000179Build
180
Tim Peters639295f2002-04-21 07:30:30 +0000181- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
182 say how or when to configure it, or how to turn it off.
183
Martin v. Löwis1142de32002-03-29 16:28:31 +0000184- On Unix, a shared libpython2.3.so can be created with --enable-shared.
185
Tim Peters8deda702002-03-30 10:06:07 +0000186- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
187 preprocessor symbols were eliminated. The internal decisions they
188 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000189
Fred Drake7d28b732002-05-02 21:17:00 +0000190- The tools used to build the documentation now work under Cygwin as
191 well as Unix.
192
Tim Petersaf8446f2001-12-21 21:36:50 +0000193C API
194
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000195- Added new macro PySequence_ITEM(o, i) that directly calls
196 sq_item without rechecking that o is a sequence and without
197 adjusting for negative indices.
198
Fred Draked0ba6362002-05-02 21:28:26 +0000199- PyRange_New() now raises ValueError if the fourth argument is not 1.
200 This is part of the removal of deprecated features of the xrange
201 object.
202
Guido van Rossum517c7d42002-04-26 02:49:14 +0000203- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
204 coercion if both arguments have the same type but this type has the
205 CHECKTYPES flag set. This is to better support proxies.
206
Neil Schemenauer9344b142002-04-12 23:00:08 +0000207- The type of tp_free has been changed from "void (*)(PyObject *)" to
208 "void (*)(void *)".
209
210- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
211
Guido van Rossum0986d822002-04-08 01:38:42 +0000212- A type can now inherit its metatype from its base type. Previously,
213 when PyType_Ready() was called, if ob_type was found to be NULL, it
214 was always set to &PyType_Type; now it is set to base->ob_type,
215 where base is tp_base, defaulting to &PyObject_Type.
216
217- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
218
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000219- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000220
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000221- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000222 without going through the buffer API.
223
Martin v. Löwis7198a522002-01-01 19:59:11 +0000224- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
225
Tim Peters10a3bb52001-12-25 19:07:38 +0000226- An old #define of ANY as void has been removed from pyport.h. This
227 hasn't been used since Python's pre-ANSI days, and the #define has
228 been marked as obsolete since then. SF bug 495548 says it created
229 conflicts with other packages, so keeping it around wasn't harmless.
230
Tim Petersaf8446f2001-12-21 21:36:50 +0000231- Because Python's magic number scheme broke on January 1st, we decided
232 to stop Python development. Thanks for all the fish!
233
Tim Petersfb05db22002-03-11 00:24:00 +0000234- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000235 scheme to a new one. See Python/import.c for details.
236
Tim Petersaf8446f2001-12-21 21:36:50 +0000237New platforms
238
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000239- GNU/Hurd is now supported.
240
Tim Petersaf8446f2001-12-21 21:36:50 +0000241Tests
242
243Windows
244
Tim Peters08e72952002-04-16 20:48:01 +0000245- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
246 of that has been fixed in the installer (disabled Wise's "delete in-
247 use files" uninstall option).
248
Guido van Rossum181e41a2002-04-06 00:23:25 +0000249- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
250
Tim Peters33187922002-04-04 20:02:04 +0000251- The installer now installs Start menu shortcuts under (the local
252 equivalent of) "All Users" when doing an Admin install.
253
Tim Petersfb05db22002-03-11 00:24:00 +0000254- file.truncate([newsize]) now works on Windows for all newsize values.
255 It used to fail if newsize didn't fit in 32 bits, reflecting a
256 limitation of MS _chsize (which is no longer used).
257
Tim Petersab034fa2002-02-01 11:27:43 +0000258- os.waitpid() is now implemented for Windows, and can be used to block
259 until a specified process exits. This is similar to, but not exactly
260 the same as, os.waitpid() on POSIX systems. If you're waiting for
261 a specific process whose pid was obtained from one of the spawn()
262 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000263 See the docs for details. The docs were changed to clarify that
264 spawn functions return, and waitpid requires, a process handle on
265 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000266
Tim Peters11bd9942002-02-01 00:52:29 +0000267- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000268 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000269 to a nasty problem: before 2.3, if you got a temp file on Windows, it
270 got wrapped in an object whose close() method first closed the
271 underlying file, then deleted the file. This usually worked fine.
272 However, the spawn family of functions on Windows create (at a low C
273 level) the same set of open files in the spawned process Q as were
274 open in the spawning process P. If a temp file f was among them, then
275 doing f.close() in P first closed P's C-level file handle on f, but Q's
276 C-level file handle on f remained open, so the attempt in P to delete f
277 blew up with a "Permission denied" error (Windows doesn't allow
278 deleting open files). This was surprising, subtle, and difficult to
279 work around.
280
281- The os module now exports all the symbolic constants usable with the
282 low-level os.open() on Windows: the new constants in 2.3 are
283 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
284 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
285 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
286 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
287 (so specify both if you want both; note that neither is useful unless
288 specified with O_CREAT too).
289
Tim Petersaf8446f2001-12-21 21:36:50 +0000290Mac
291
292
Tim Peters909c0912001-12-14 23:16:18 +0000293What's New in Python 2.2 final?
294Release date: 21-Dec-2001
295===============================
296
297Type/class unification and new-style classes
298
Barry Warsaw52acb492001-12-21 20:04:22 +0000299- pickle.py, cPickle: allow pickling instances of new-style classes
300 with a custom metaclass.
301
Tim Peters909c0912001-12-14 23:16:18 +0000302Core and builtins
303
Barry Warsaw52acb492001-12-21 20:04:22 +0000304- weakref proxy object: when comparing, unwrap both arguments if both
305 are proxies.
306
Tim Peters909c0912001-12-14 23:16:18 +0000307Extension modules
308
Barry Warsaw52acb492001-12-21 20:04:22 +0000309- binascii.b2a_base64(): fix a potential buffer overrun when encoding
310 very short strings.
311
312- cPickle: the obscure "fast" mode was suspected of causing stack
313 overflows on the Mac. Hopefully fixed this by setting the recursion
314 limit much smaller. If the limit is too low (it only affects
315 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
316 when compiling cPickle.c (or in pyconfig.h).
317
Tim Peters909c0912001-12-14 23:16:18 +0000318Library
319
Barry Warsaw52acb492001-12-21 20:04:22 +0000320- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
321 close or delete time).
322
323- rfc822.py: fixed a bug where the address '<>' was converted to None
324 instead of an empty string (also fixes the email.Utils module).
325
326- xmlrpclib.py: version 1.0.0; uses precision for doubles.
327
328- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000329 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000330
Tim Peters909c0912001-12-14 23:16:18 +0000331Tools/Demos
332
333Build
334
335C API
336
337New platforms
338
339Tests
340
341Windows
342
Barry Warsaw52acb492001-12-21 20:04:22 +0000343- distutils package: fixed broken Windows installers (bdist_wininst).
344
345- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
346 instances are deleted at process exit time.
347
348- socket.py: prevent mysterious warnings when socket instances are
349 deleted at process exit time.
350
351- posixmodule.c: fix a Windows crash with stat() of a filename ending
352 in backslash.
353
Tim Peters909c0912001-12-14 23:16:18 +0000354Mac
355
Barry Warsaw52acb492001-12-21 20:04:22 +0000356- The Carbon toolbox modules have been upgraded to Universal Headers
357 3.4, and experimental CoreGraphics and CarbonEvents modules have
358 been added. All only for framework-enabled MacOSX.
359
Tim Peters909c0912001-12-14 23:16:18 +0000360
Tim Peters6272dfd2001-12-13 19:34:00 +0000361What's New in Python 2.2c1?
362Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000363===========================
364
365Type/class unification and new-style classes
366
Barry Warsaw06557452001-12-14 20:47:12 +0000367- Guido's tutorial introduction to the new type/class features has
368 been extensively updated. See
369
370 http://www.python.org/2.2/descrintro.html
371
372 That remains the primary documentation in this area.
373
Guido van Rossum33bab012001-12-05 22:45:48 +0000374- Fixed a leak: instance variables declared with __slots__ were never
375 deleted!
376
Guido van Rossum4b800852001-12-03 00:54:52 +0000377- The "delete attribute" method of descriptor objects is called
378 __delete__, not __del__. In previous releases, it was mistakenly
379 called __del__, which created an unfortunate overloading condition
380 with finalizers. (The "get attribute" and "set attribute" methods
381 are still called __get__ and __set__, respectively.)
382
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000383- Some subtle issues with the super built-in were fixed:
384
385 (a) When super itself is subclassed, its __get__ method would still
386 return an instance of the base class (i.e., of super).
387
388 (b) super(C, C()).__class__ would return C rather than super. This
389 is confusing. To fix this, I decided to change the semantics of
390 super so that it only applies to code attributes, not to data
391 attributes. After all, overriding data attributes is not
392 supported anyway.
393
394 (c) The __get__ method didn't check whether the argument was an
395 instance of the type used in creation of the super instance.
396
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000397- Previously, hash() of an instance of a subclass of a mutable type
398 (list or dictionary) would return some value, rather than raising
399 TypeError. This has been fixed. Also, directly calling
400 dict.__hash__ and list.__hash__ now raises the same TypeError
401 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000402
Guido van Rossumd331cb52001-12-05 19:46:42 +0000403- New-style objects now support deleting their __dict__. This is for
404 all intents and purposes equivalent to assigning a brand new empty
405 dictionary, but saves space if the object is not used further.
406
Tim Petersb3c9af12001-11-17 00:21:57 +0000407Core and builtins
408
Tim Peters3caca232001-12-06 06:23:26 +0000409- -Qnew now works as documented in PEP 238: when -Qnew is passed on
410 the command line, all occurrences of "/" use true division instead
411 of classic division. See the PEP for details. Note that "all"
412 means all instances in library and 3rd-party modules, as well as in
413 your own code. As the PEP says, -Qnew is intended for use only in
414 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000415 Note that test_coercion.py in the standard Python test suite fails
416 under -Qnew; this is expected, and won't be repaired until true
417 division becomes the default (in the meantime, test_coercion is
418 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000419
Fred Drake6c01e252001-12-14 17:08:12 +0000420- complex() now only allows the first argument to be a string
421 argument, and raises TypeError if either the second arg is a string
422 or if the second arg is specified when the first is a string.
423
Tim Petersb3c9af12001-11-17 00:21:57 +0000424Extension modules
425
Martin v. Löwis560da622001-11-24 09:24:51 +0000426- gc.get_referents was renamed to gc.get_referrers.
427
Tim Petersb3c9af12001-11-17 00:21:57 +0000428Library
429
Tim Peters25059d32001-12-07 20:35:43 +0000430- Functions in the os.spawn() family now release the global interpreter
431 lock around calling the platform spawn. They should always have done
432 this, but did not before 2.2c1. Multithreaded programs calling
433 an os.spawn function with P_WAIT will no longer block all Python threads
434 until the spawned program completes. It's possible that some programs
435 relies on blocking, although more likely by accident than by design.
436
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000437- webbrowser defaults to netscape.exe on OS/2 now.
438
Martin v. Löwis652e1912001-11-25 14:50:56 +0000439- Tix.ResizeHandle exposes detach_widget, hide, and show.
440
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000441- The charset alias windows_1252 has been added.
442
Barry Warsaw06557452001-12-14 20:47:12 +0000443- types.StringTypes is a tuple containing the defined string types;
444 usually this will be (str, unicode), but if Python was compiled
445 without Unicode support it will be just (str,).
446
447- The pulldom and minidom modules were synchronized to PyXML.
448
Tim Petersb3c9af12001-11-17 00:21:57 +0000449Tools/Demos
450
Barry Warsaw06557452001-12-14 20:47:12 +0000451- A new script called Tools/scripts/google.py was added, which fires
452 off a search on Google.
453
Tim Petersb3c9af12001-11-17 00:21:57 +0000454Build
455
Barry Warsaw06557452001-12-14 20:47:12 +0000456- Note that release builds of Python should arrange to define the
457 preprocessor symbol NDEBUG on the command line (or equivalent).
458 In the 2.2 pre-release series we tried to define this by magic in
459 Python.h instead, but it proved to cause problems for extension
460 authors. The Unix, Windows and Mac builds now all define NDEBUG in
461 release builds via cmdline (or equivalent) instead. Ports to
462 other platforms should do likewise.
463
Jack Jansen1999ef42001-12-06 21:47:20 +0000464- It is no longer necessary to use --with-suffix when building on a
465 case-insensitive file system (such as Mac OS X HFS+). In the build
466 directory an extension is used, but not in the installed python.
467
Tim Petersb3c9af12001-11-17 00:21:57 +0000468C API
469
Tim Petersf582b822001-12-11 18:51:08 +0000470- New function PyDict_MergeFromSeq2() exposes the builtin dict
471 constructor's logic for updating a dictionary from an iterable object
472 producing key-value pairs.
473
Tim Peterscffed4b2001-11-29 03:26:37 +0000474- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000475 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000476 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
477 dump core in some bad cases. This has been repaired. As a result,
478 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
479 previously went unchallenged.
480
Tim Petersb3c9af12001-11-17 00:21:57 +0000481New platforms
482
483Tests
484
485Windows
486
487Mac
488
Jack Jansenffa260f2001-12-06 21:14:00 +0000489- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
490 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000491
Barry Warsaw06557452001-12-14 20:47:12 +0000492- Changed logic for finding python home in Mac OS X framework Pythons.
493 Now sys.executable points to the executable again, in stead of to
494 the shared library. The latter is used only for locating the python
495 home.
496
497
Tim Peters84362bc2001-10-19 17:55:30 +0000498What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000499Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000500===========================
501
502Type/class unification and new-style classes
503
Guido van Rossum3d27df02001-11-15 20:27:54 +0000504- Multiple inheritance mixing new-style and classic classes in the
505 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000506
507 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000508 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000509
510 The MRO (method resolution order) for each base class is respected
511 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000512 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000513 This needs to be documented.
514
Tim Petersa427a2b2001-10-29 22:25:45 +0000515- The new builtin dictionary() constructor, and dictionary type, have
516 been renamed to dict. This reflects a decade of common usage.
517
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000518- dict() now accepts an iterable object producing 2-sequences. For
519 example, dict(d.items()) == d for any dictionary d. The argument,
520 and the elements of the argument, can be any iterable objects.
521
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000522- New-style classes can now have a __del__ method, which is called
523 when the instance is deleted (just like for classic classes).
524
Guido van Rossum12d955c2001-10-26 14:56:06 +0000525- Assignment to object.__dict__ is now possible, for objects that are
526 instances of new-style classes that have a __dict__ (unless the base
527 class forbids it).
528
Guido van Rossumc8e56452001-10-22 00:43:43 +0000529- Methods of built-in types now properly check for keyword arguments
530 (formerly these were silently ignored). The only built-in methods
531 that take keyword arguments are __call__, __init__ and __new__.
532
Guido van Rossum86443212001-10-27 22:28:54 +0000533- The socket function has been converted to a type; see below.
534
Tim Peters84362bc2001-10-19 17:55:30 +0000535Core and builtins
536
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000537- Assignment to __debug__ raises SyntaxError at compile-time. This
538 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000539 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000540
Guido van Rossum12d955c2001-10-26 14:56:06 +0000541- Clarified the error messages for unsupported operands to an operator
542 (like 1 + '').
543
Tim Peters84362bc2001-10-19 17:55:30 +0000544Extension modules
545
Tim Peters5ebfd362001-11-13 23:11:19 +0000546- mmap has a new keyword argument, "access", allowing a uniform way for
547 both Windows and Unix users to create read-only, write-through and
548 copy-on-write memory mappings. This was previously possible only on
549 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000550 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000551 platforms. Thanks to Jay T Miller for repairing this!
552
Tim Peters169ded02001-11-03 19:57:21 +0000553- By default, the gc.garbage list now contains only those instances in
554 unreachable cycles that have __del__ methods; in 2.1 it contained all
555 instances in unreachable cycles. "Instances" here has been generalized
556 to include instances of both new-style and old-style classes.
557
Guido van Rossum12d955c2001-10-26 14:56:06 +0000558- The socket module defines a new method for socket objects,
559 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000560 send() until all data has been sent. Also, the socket function has
561 been converted to a subclassable type, like list and tuple (etc.)
562 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000563
564- Various bugfixes to the curses module. There is now a test suite
565 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000566
Guido van Rossum692adf12001-10-30 03:03:03 +0000567- binascii.b2a_base64 no longer places an arbitrary restriction of 57
568 bytes on its input.
569
Tim Peters84362bc2001-10-19 17:55:30 +0000570Library
571
Tim Peters5ebfd362001-11-13 23:11:19 +0000572- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000573 convenience function.
574
Tim Peters75335872001-11-03 19:35:43 +0000575- Symbolic group names in regular expressions must be unique. For
576 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
577 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000578 Python 2.2 detects this error at regexp compilation time;
579 previously, the error went undetected, and results were
580 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
581 pattern.subn() methods have been rewritten in C. Also, an
582 experimental function/method finditer() has been added, which works
583 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000584
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000585- Tix exposes more commands through the classes DirSelectBox,
586 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
587 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
588 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
589
Tim Peters98791af2001-10-23 01:59:54 +0000590- Traceback objects are now scanned by cyclic garbage collection, so
591 cycles created by casual use of sys.exc_info() no longer cause
592 permanent memory leaks (provided garbage collection is enabled).
593
Guido van Rossum49192142001-10-24 20:51:44 +0000594- os.extsep -- a new variable needed by the RISCOS support. It is the
595 separator used by extensions, and is '.' on all platforms except
596 RISCOS, where it is '/'. There is no need to use this variable
597 unless you have a masochistic desire to port your code to RISCOS.
598
Barry Warsaw012852b2001-11-16 16:17:27 +0000599- mimetypes.py has optional support for non-standard, but commonly
600 found types. guess_type() and guess_extension() now accept an
601 optional `strict' flag, defaulting to true, which controls whether
602 recognize non-standard types or not. A few non-standard types we
603 know about have been added. Also, when run as a script, there are
604 new -l and -e options.
605
606- statcache is now deprecated.
607
608- email.Utils.formatdate() now produces the preferred RFC 2822 style
609 dates with numeric timezones (it used to produce obsolete dates
610 hard coded to "GMT" timezone). An optional `localtime' flag is
611 added to produce dates in the local timezone, with daylight savings
612 time properly taken into account.
613
614- In pickle and cPickle, instead of masking errors in load() by
615 transforming them into SystemError, we let the original exception
616 propagate out. Also, implement support for __safe_for_unpickling__
617 in pickle, as it already was supported in cPickle.
618
Tim Peters84362bc2001-10-19 17:55:30 +0000619Tools/Demos
620
621Build
622
Barry Warsaw012852b2001-11-16 16:17:27 +0000623- The dbm module is built using libdb1 if available. The bsddb module
624 is built with libdb3 if available.
625
626- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
627
Tim Peters84362bc2001-10-19 17:55:30 +0000628C API
629
Tim Peters1fc240e2001-10-26 05:06:50 +0000630- New function PySequence_Fast_GET_SIZE() returns the size of a non-
631 NULL result from PySequence_Fast(), more quickly than calling
632 PySequence_Size().
633
Barry Warsaw012852b2001-11-16 16:17:27 +0000634- New argument unpacking function PyArg_UnpackTuple() added.
635
636- New functions PyObject_CallFunctionObjArgs() and
637 PyObject_CallMethodObjArgs() have been added to make it more
638 convenient and efficient to call functions and methods from C.
639
640- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
641 possible that this will propagate errors it didn't before.
642
643- New function PyObject_CheckReadBuffer(), which returns true if its
644 argument supports the single-segment readable buffer interface.
645
Tim Peters84362bc2001-10-19 17:55:30 +0000646New platforms
647
Guido van Rossum86443212001-10-27 22:28:54 +0000648- We've finally confirmed that this release builds on HP-UX 11.00,
649 *with* threads, and passes the test suite.
650
Tim Peters7a33d8b2001-11-05 02:51:07 +0000651- Thanks to a series of patches from Michael Muller, Python may build
652 again under OS/2 Visual Age C++.
653
Guido van Rossum49192142001-10-24 20:51:44 +0000654- Updated RISCOS port by Dietmar Schwertberger.
655
Tim Peters84362bc2001-10-19 17:55:30 +0000656Tests
657
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000658- Added a test script for the curses module. It isn't run automatically;
659 regrtest.py must be run with '-u curses' to enable it.
660
Tim Peters84362bc2001-10-19 17:55:30 +0000661Windows
662
Barry Warsaw012852b2001-11-16 16:17:27 +0000663Mac
664
665- PythonScript has been moved to unsupported and is slated to be
666 removed completely in the next release.
667
668- It should now be possible to build applets that work on both OS9 and
669 OSX.
670
671- The core is now linked with CoreServices not Carbon; as a side
672 result, default 8bit encoding on OSX is now ASCII.
673
674- Python should now build on OSX 10.1.1
675
Tim Peters84362bc2001-10-19 17:55:30 +0000676
Tim Petersabf925f2001-09-28 21:53:42 +0000677What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000678Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000679===========================
680
681Type/class unification and new-style classes
682
Guido van Rossum687ae002001-10-15 22:03:32 +0000683- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000684 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000685 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000686 remains: the __dict__ of a new-style class is a read-only proxy; you
687 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000688 __defined__ attribute of new-style types no longer exists, for lack
689 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000690 future a __cache__ may be resurrected with a similar function, if I
691 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000692
Tim Peters1c9ca872001-10-04 06:43:12 +0000693- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
694 always returned None, even when there was a class docstring).
695
696- doctest now finds and runs docstrings attached to new-style classes,
697 class methods, static methods, and properties.
698
Guido van Rossum9074ef62001-10-16 21:34:49 +0000699Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000700
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000701- A very subtle syntactical pitfall in list comprehensions was fixed.
702 For example: [a+b for a in 'abc', for b in 'def']. The comma in
703 this example is a mistake. Previously, this would silently let 'a'
704 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
705 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
706 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
707 Note that [a for a in <singleton>] is a convoluted way to say
708 [<singleton>] anyway, so it's not like any expressiveness is lost.
709
Guido van Rossum9074ef62001-10-16 21:34:49 +0000710- getattr(obj, name, default) now only catches AttributeError, as
711 documented, rather than returning the default value for all
712 exceptions (which could mask bugs in a __getattr__ hook, for
713 example).
714
Fred Drakecb7a6b52001-10-22 18:41:51 +0000715- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000716 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000717 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000718 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000719
Guido van Rossum1c486092001-10-19 02:05:35 +0000720- unicode(obj) now behaves more like str(obj), accepting arbitrary
721 objects, and calling a __unicode__ method if it exists.
722 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000723 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000724
Barry Warsawf6fb1712001-10-19 05:35:40 +0000725- isinstance() now allows any object as the first argument and a
726 class, a type or something with a __bases__ tuple attribute for the
727 second argument. The second argument may also be a tuple of a
728 class, type, or something with __bases__, in which case isinstance()
729 will return true if the first argument is an instance of any of the
730 things contained in the second argument tuple. E.g.
731
732 isinstance(x, (A, B))
733
734 returns true if x is an instance of A or B.
735
Guido van Rossum9074ef62001-10-16 21:34:49 +0000736Extension modules
737
738- thread.start_new_thread() now returns the thread ID (previously None).
739
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000740- binascii has now two quopri support functions, a2b_qp and b2a_qp.
741
Guido van Rossumc524d952001-10-19 01:31:59 +0000742- readline now supports setting the startup_hook and the
743 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000744
Guido van Rossumc524d952001-10-19 01:31:59 +0000745- os and posix supports chroot(), setgroups() and unsetenv() where
746 available. The stat(), fstat(), statvfs() and fstatvfs() functions
747 now return "pseudo-sequences" -- the various fields can now be
748 accessed as attributes (e.g. os.stat("/").st_mtime) but for
749 backwards compatibility they also behave as a fixed-length sequence.
750 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000751 attributes.
752
753- time: localtime(), gmtime() and strptime() now return a
754 pseudo-sequence similar to the os.stat() return value, with
755 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000756
Guido van Rossum9074ef62001-10-16 21:34:49 +0000757- Decompression objects in the zlib module now accept an optional
758 second parameter to decompress() that specifies the maximum amount
759 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000760
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000761- optional SSL support in the socket module now exports OpenSSL
762 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
763 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000764 automatically seed its PRNG. Also, the keyfile and certfile
765 arguments to socket.ssl() are now optional.
766
767- posixmodule (and by extension, the os module on POSIX platforms) now
768 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000769
Guido van Rossum9074ef62001-10-16 21:34:49 +0000770Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000771
Tim Peters7402f792001-10-02 03:53:41 +0000772- doctest now excludes functions and classes not defined by the module
773 being tested, thanks to Tim Hochberg.
774
Fred Drakecb7a6b52001-10-22 18:41:51 +0000775- HotShot, a new profiler implemented using a C-based callback, has
776 been added. This substantially reduces the overhead of profiling,
777 but it is still quite preliminary. Support modules and
778 documentation will be added in upcoming releases (before 2.2 final).
779
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000780- profile now produces correct output in situations where an exception
781 raised in Python is cleared by C code (e.g. hasattr()). This used
782 to cause wrong output, including spurious claims of recursive
783 functions and attribution of time spent to the wrong function.
784
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000785 The code and documentation for the derived OldProfile and HotProfile
786 profiling classes was removed. The code hasn't worked for years (if
787 you tried to use them, they raised exceptions). OldProfile
788 intended to reproduce the behavior of the profiler Python used more
789 than 7 years ago, and isn't interesting anymore. HotProfile intended
790 to provide a faster profiler (but producing less information), and
791 that's a worthy goal we intend to meet via a different approach (but
792 without losing information).
793
Tim Peterscce092d2001-10-09 05:31:56 +0000794- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000795 a much better system-specific calibration constant. The constant can
796 now be specified in an instance constructor, or as a Profile class or
797 instance variable, instead of by editing profile.py's source code.
798 Calibration must still be done manually (see the docs for the profile
799 module).
800
801 Note that Profile.calibrate() must be overriden by subclasses.
802 Improving the accuracy required exploiting detailed knowledge of
803 profiler internals; the earlier method abstracted away the details
804 and measured a simplified model instead, but consequently computed
805 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000806
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000807- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000808 which indicates whether output is intended for the header 'Q'
809 encoding.
810
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000811- The SocketServer.ThreadingMixIn class now closes the request after
812 finish_request() returns. (Not when it errors out though.)
813
Barry Warsawf6fb1712001-10-19 05:35:40 +0000814- The nntplib module's NNTP.body() method has grown a `file' argument
815 to allow saving the message body to a file.
816
817- The email package has added a class email.Parser.HeaderParser which
818 only parses headers and does not recurse into the message's body.
819 Also, the module/class MIMEAudio has been added for representing
820 audio data (contributed by Anthony Baxter).
821
822- ftplib should be able to handle files > 2GB.
823
824- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
825 ON, and OFF.
826
Fred Drakecb7a6b52001-10-22 18:41:51 +0000827- xml.dom.minidom NodeList objects now support the length attribute
828 and item() method as required by the DOM specifications.
829
Guido van Rossumed554f62001-10-02 23:15:37 +0000830Tools/Demos
831
832- Demo/dns was removed. It no longer serves any purpose; a package
833 derived from it is now maintained by Anthony Baxter, see
834 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000835
Barry Warsawf6fb1712001-10-19 05:35:40 +0000836- The freeze tool has been made more robust, and two new options have
837 been added: -X and -E.
838
Tim Petersabf925f2001-09-28 21:53:42 +0000839Build
840
Barry Warsawf6fb1712001-10-19 05:35:40 +0000841- configure will use CXX in LINKCC if CXX is used to build main() and
842 the system requires to link a C++ main using the C++ compiler.
843
Tim Petersabf925f2001-09-28 21:53:42 +0000844C API
845
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000846- The documentation for the tp_compare slot is updated to require that
847 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
848 not correct. This is not yet enforced but will be enforced in
849 Python 2.3; even later, we may use -2 to indicate errors and +2 for
850 "NotImplemented". Right now, -1 should be used for an error return.
851
Tim Petersd38b1c72001-09-30 05:09:37 +0000852- PyLong_AsLongLong() now accepts int (as well as long) arguments.
853 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
854 as long) arguments.
855
Guido van Rossum3c288632001-10-16 21:13:49 +0000856- PyThread_start_new_thread() now returns a long int giving the thread
857 ID, if one can be calculated; it returns -1 for error, 0 if no
858 thread ID is calculated (this is an incompatible change, but only
859 the thread module used this API). This code has only really been
860 tested on Linux and Windows; other platforms please beware (and
861 report any bugs or strange behavior).
862
Guido van Rossum1c486092001-10-19 02:05:35 +0000863- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
864 input.
865
Tim Petersabf925f2001-09-28 21:53:42 +0000866New platforms
867
868Tests
869
870Windows
871
Tim Peters04cf1d32001-10-09 22:39:40 +0000872- Installer: If you install IDLE, and don't disable file-extension
873 registration, a new "Edit with IDLE" context (right-click) menu entry
874 is created for .py and .pyw files.
875
Tim Peters1ce3cf72001-10-01 17:58:40 +0000876- The signal module now supports SIGBREAK on Windows, thanks to Steven
877 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
878 action remains to call Win32 ExitProcess(). This can be changed via
879 signal.signal(). For example:
880
881 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
882 # (SIGINT) behavior.
883 import signal
884 signal.signal(signal.SIGBREAK,
885 signal.default_int_handler)
886
887 try:
888 while 1:
889 pass
890 except KeyboardInterrupt:
891 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
892 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
893 # program without the possibility for any Python-level cleanup).
894 print "Clean exit"
895
Tim Petersabf925f2001-09-28 21:53:42 +0000896
Tim Petersb07352e2001-09-08 01:25:47 +0000897What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000898Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000899===========================
900
Guido van Rossum808eea72001-09-25 04:15:41 +0000901Type/class unification and new-style classes
902
903- pydoc and inspect are now aware of new-style classes;
904 e.g. help(list) at the interactive prompt now shows proper
905 documentation for all operations on list objects.
906
907- Applications using Jim Fulton's ExtensionClass module can now safely
908 be used with Python 2.2. In particular, Zope 2.4.1 now works with
909 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
910 examples also work again. It is hoped that Gtk and Boost also work
911 with 2.2a4 and beyond. (If you can confirm this, please write
912 webmaster@python.org; if there are still problems, please open a bug
913 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000914
Tim Peters66c1a522001-09-24 21:17:50 +0000915- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000916 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +0000917 in the constructed property object. fget, fset and fdel weren't
918 discoverable from Python in 2.2a3. __doc__ is new, and allows to
919 associate a docstring with a property.
920
Guido van Rossum808eea72001-09-25 04:15:41 +0000921- Comparison overloading is now more completely implemented. For
922 example, a str subclass instance can properly be compared to a str
923 instance, and it can properly overload comparison. Ditto for most
924 other built-in object types.
925
926- The repr() of new-style classes has changed; instead of <type
927 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
928 *except* for built-in types, which are still rendered as <type
929 'Foo'> (to avoid upsetting existing code that might parse or
930 otherwise rely on repr() of certain type objects).
931
932- The repr() of new-style objects is now always <Foo object at XXX>;
933 previously, it was sometimes <Foo instance at XXX>.
934
935- For new-style classes, what was previously called __getattr__ is now
936 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000937 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000938 one in classic classes is defined which is called only if regular
939 attribute access raises AttributeError; to catch *all* attribute
940 access, you can use __getattribute__ (for new-style classes). If
941 both are defined, __getattribute__ is called first, and if it raises
942 AttributeError, __getattr__ is called.
943
944- The __class__ attribute of new-style objects can be assigned to.
945 The new class must have the same C-level object layout as the old
946 class.
947
948- The builtin file type can be subclassed now. In the usual pattern,
949 "file" is the name of the builtin type, and file() is a new builtin
950 constructor, with the same signature as the builtin open() function.
951 file() is now the preferred way to open a file.
952
953- Previously, __new__ would only see sequential arguments passed to
954 the type in a constructor call; __init__ would see both sequential
955 and keyword arguments. This made no sense whatsoever any more, so
956 now both __new__ and __init__ see all arguments.
957
958- Previously, hash() applied to an instance of a subclass of str or
959 unicode always returned 0. This has been repaired.
960
961- Previously, an operation on an instance of a subclass of an
962 immutable type (int, long, float, complex, tuple, str, unicode),
963 where the subtype didn't override the operation (and so the
964 operation was handled by the builtin type), could return that
965 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000966 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +0000967 with the same value as s.
968
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000969- Provisional support for pickling new-style objects has been added.
970
Guido van Rossum808eea72001-09-25 04:15:41 +0000971Core
972
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000973- file.writelines() now accepts any iterable object producing strings.
974
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000975- PyUnicode_FromEncodedObject() now works very much like
976 PyObject_Str(obj) in that it tries to use __str__/tp_str
977 on the object if the object is not a string or buffer. This
978 makes unicode() behave like str() when applied to non-string/buffer
979 objects.
980
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000981- PyFile_WriteObject now passes Unicode objects to the file's write
982 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000983 of a print statement must support Unicode objects, i.e. they must
984 at least convert them into ASCII strings.
985
Guido van Rossum624c8af2001-09-18 15:21:04 +0000986- Thread scheduling on Solaris should be improved; it is no longer
987 necessary to insert a small sleep at the start of a thread in order
988 to let other runnable threads be scheduled.
989
Tim Petersb07352e2001-09-08 01:25:47 +0000990Library
991
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000992- StringIO.StringIO instances and cStringIO.StringIO instances support
993 read character buffer compatible objects for their .write() methods.
994 These objects are converted to strings and then handled as such
995 by the instances.
996
Barry Warsaw2f600732001-09-24 04:28:10 +0000997- The "email" package has been added. This is basically a port of the
998 mimelib package <http://sf.net/projects/mimelib> with API changes
999 and some implementations updated to use iterators and generators.
1000
Tim Peters8a9c2842001-09-22 21:30:22 +00001001- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1002 restores the ability of Tools/scripts/ndiff.py to start producing output
1003 before the entire comparison is complete.
1004
Barry Warsaw58b072d2001-09-22 04:44:21 +00001005- StringIO.StringIO instances and cStringIO.StringIO instances support
1006 iteration just like file objects (i.e. their .readline() method is
1007 called for each iteration until it returns an empty string).
1008
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001009- The codecs module has grown four new helper APIs to access
1010 builtin codecs: getencoder(), getdecoder(), getreader(),
1011 getwriter().
1012
Guido van Rossum624c8af2001-09-18 15:21:04 +00001013- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1014 simplifies writing XML RPC servers.
1015
Barry Warsaw647d5e82001-09-28 17:01:02 +00001016- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001017 after interpretation of symbolic links. On non-Unix systems, this
1018 is an alias for os.path.abspath().
1019
Tim Peters16a77ad2001-09-08 04:00:12 +00001020- operator.indexOf() (PySequence_Index() in the C API) now works with any
1021 iterable object.
1022
Guido van Rossum624c8af2001-09-18 15:21:04 +00001023- smtplib now supports various authentication and security features of
1024 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001025
Guido van Rossum624c8af2001-09-18 15:21:04 +00001026- hmac: a new module implementing keyed hashing for message
1027 authentication.
1028
1029- mimetypes now recognizes more extensions and file types. At the
1030 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001031
Guido van Rossum624c8af2001-09-18 15:21:04 +00001032- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001033 Python 2.2 bytecode generation. It has also been promoted from a
1034 Tool to a standard library package. (Tools/compiler still exists as
1035 a sample driver.)
1036
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001037Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001038
Tim Petersb07352e2001-09-08 01:25:47 +00001039Build
1040
Guido van Rossum624c8af2001-09-18 15:21:04 +00001041- Large file support (LFS) is now automatic when the platform supports
1042 it; no more manual configuration tweaks are needed. On Linux, at
1043 least, it's possible to have a system whose C library supports large
1044 files but whose kernel doesn't; in this case, large file support is
1045 still enabled but doesn't do you any good unless you upgrade your
1046 kernel or share your Python executable with another system whose
1047 kernel has large file support.
1048
1049- The configure script now supplies plausible defaults in a
1050 cross-compilation environment. This doesn't mean that the supplied
1051 values are always correct, or that cross-compilation now works
1052 flawlessly -- but it's a first step (and it shuts up most of
1053 autoconf's warnings about AC_TRY_RUN).
1054
1055- The Unix build is now a bit less chatty, courtesy of the parser
1056 generator. The build is completely silent (except for errors) when
1057 using "make -s", thanks to a -q option to setup.py.
1058
Tim Petersb07352e2001-09-08 01:25:47 +00001059C API
1060
Guido van Rossum624c8af2001-09-18 15:21:04 +00001061- The "structmember" API now supports some new flag bits to deny read
1062 and/or write access to attributes in restricted execution mode.
1063
Tim Petersb07352e2001-09-08 01:25:47 +00001064New platforms
1065
Guido van Rossum624c8af2001-09-18 15:21:04 +00001066- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1067 (http://familiar.handhelds.org).
1068
Tim Petersb07352e2001-09-08 01:25:47 +00001069Tests
1070
Tim Peters8a9c2842001-09-22 21:30:22 +00001071- The "classic" standard tests, which work by comparing stdout to
1072 an expected-output file under Lib/test/output/, no longer stop at
1073 the first mismatch. Instead the test is run to completion, and a
1074 variant of ndiff-style comparison is used to report all differences.
1075 This is much easier to understand than the previous style of reporting.
1076
1077- The unittest-based standard tests now use regrtest's test_main()
1078 convention, instead of running as a side-effect of merely being
1079 imported. This allows these tests to be run in more natural and
1080 flexible ways as unittests, outside the regrtest framework.
1081
1082- regrtest.py is much better integrated with unittest and doctest now,
1083 especially in regard to reporting errors.
1084
Tim Petersb07352e2001-09-08 01:25:47 +00001085Windows
1086
Guido van Rossum624c8af2001-09-18 15:21:04 +00001087- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001088 that support it (NTFS under Windows 2000). See "What's New in
1089 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001090
Tim Petersb07352e2001-09-08 01:25:47 +00001091
Tim Petersedc99312001-08-22 21:36:50 +00001092What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001093Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001094===========================
1095
1096Core
1097
Tim Peters9fffa3e2001-09-04 05:14:19 +00001098- Conversion of long to float now raises OverflowError if the long is too
1099 big to represent as a C double.
1100
Tim Peters32f453e2001-09-03 08:35:41 +00001101- The 3-argument builtin pow() no longer allows a third non-None argument
1102 if either of the first two arguments is a float, or if both are of
1103 integer types and the second argument is negative (in which latter case
1104 the arguments are converted to float, so this is really the same
1105 restriction).
1106
Tim Peters5d2b77c2001-09-03 05:47:38 +00001107- The builtin dir() now returns more information, and sometimes much
1108 more, generally naming all attributes of an object, and all attributes
1109 reachable from the object via its class, and from its class's base
1110 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1111 an empty list. In 2.2a3,
1112
1113 >>> dir([])
1114 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1115 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1116 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1117 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1118 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1119 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1120 'reverse', 'sort']
1121
1122 dir(module) continues to return only the module's attributes, though.
1123
Tim Petersbdee63f2001-09-02 03:40:59 +00001124- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001125 than raising OverflowError. This is a partial implementation of PEP
1126 237. You can use -Wdefault::OverflowWarning to enable a warning for
1127 this situation, and -Werror::OverflowWarning to revert to the old
1128 OverflowError exception.
1129
Guido van Rossum61c345f2001-09-04 03:26:15 +00001130- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001131 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001132 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1133 -Qold, meaning the / operator has its classic meaning and no
1134 warnings are issued. Using -Qwarn issues a run-time warning about
1135 all uses of classic division for int and long arguments; -Qwarnall
1136 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001137 (for use with fixdiv.py).
1138 [Note: the remainder of this paragraph (preserved below) became
1139 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1140 <obsolete>
1141 Using -Qnew is questionable; it turns on new division by default, but
1142 only in the __main__ module. You can usefully combine -Qwarn or
1143 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1144 warns about classic division everywhere else.
1145 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001146
Tim Petersbdee63f2001-09-02 03:40:59 +00001147- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001148 long, float, str, unicode, and tuple. (The types complex, list and
1149 dictionary can also be subclassed; this was introduced earlier.)
1150 Note that restrictions apply when subclassing immutable built-in
1151 types: you can only affect the value of the instance by overloading
1152 __new__. You can add mutable attributes, and the subclass instances
1153 will have a __dict__ attribute, but you cannot change the "value"
1154 (as implemented by the base class) of an immutable subclass instance
1155 once it is created.
1156
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001157- The dictionary constructor now takes an optional argument, a
1158 mapping-like object, and initializes the dictionary from its
1159 (key, value) pairs.
1160
Tim Petersbdee63f2001-09-02 03:40:59 +00001161- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001162 "cooperative super calls" in a multiple inheritance setting. For an
1163 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1164
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001165- A new built-in type, property, has been added. This enables the
1166 creation of "properties". These are attributes implemented by
1167 getter and setter functions (or only one of these for read-only or
1168 write-only attributes), without the need to override __getattr__.
1169 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001170
Tim Petersbdee63f2001-09-02 03:40:59 +00001171- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001172 liberalized, to allow leading zeroes. Examples of literals now
1173 legal that were SyntaxErrors before:
1174
1175 00.0 0e3 0100j 07.5 00000000000000000008.
1176
Tim Petersbdee63f2001-09-02 03:40:59 +00001177- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001178 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1179
Tim Petersedc99312001-08-22 21:36:50 +00001180Library
1181
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001182- telnetlib includes symbolic names for the options, and support for
1183 setting an option negotiation callback.
1184
Tim Petersa40c7932001-09-05 22:36:56 +00001185- The new C standard no longer requires that math libraries set errno to
1186 ERANGE on overflow. For platform libraries that exploit this new
1187 freedom, Python's overflow-checking was wholly broken. A new overflow-
1188 checking scheme attempts to repair that, but may not be reliable on all
1189 platforms (C doesn't seem to provide anything both useful and portable
1190 in this area anymore).
1191
Martin v. Löwis44f86962001-09-05 13:44:54 +00001192- Asynchronous timeout actions are available through the new class
1193 threading.Timer.
1194
Tim Peters78526162001-09-05 00:53:45 +00001195- math.log and math.log10 now return sensible results for even huge
1196 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1197
Tim Petersbdee63f2001-09-02 03:40:59 +00001198- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001199 currently held. See the docs for the imp module.
1200
Tim Petersbdee63f2001-09-02 03:40:59 +00001201- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001202 dumps containing ints written on platforms where Python ints are 8 bytes.
1203 When read on a box where Python ints are 4 bytes, such values are
1204 converted to Python longs.
1205
Tim Petersbdee63f2001-09-02 03:40:59 +00001206- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001207 code objects is no longer allowed. This plugs a security hole.
1208
Steve Purcell6091cd62001-09-06 16:05:17 +00001209- unittest.TestResult instances no longer store references to tracebacks
1210 generated by test failures. This prevents unexpected dangling references
1211 to objects that should be garbage collected between tests.
1212
Tim Petersedc99312001-08-22 21:36:50 +00001213Tools
1214
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001215- Tools/scripts/fixdiv.py has been added which can be used to fix
1216 division operators as per PEP 238.
1217
Tim Petersedc99312001-08-22 21:36:50 +00001218Build
1219
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001220- If you are an adventurous person using Mac OS X you may want to look at
1221 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1222 application, which can be used for experimenting with Carbon or Cocoa.
1223 Discussion of this on pythonmac-sig, please.
1224
Tim Peters7eea37e2001-09-04 22:08:56 +00001225C API
1226
1227- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001228
Tim Peters9fffa3e2001-09-04 05:14:19 +00001229- Note that PyLong_AsDouble can fail! This has always been true, but no
1230 callers checked for it. It's more likely to fail now, because overflow
1231 errors are properly detected now. The proper way to check:
1232
1233 double x = PyLong_AsDouble(some_long_object);
1234 if (x == -1.0 && PyErr_Occurred()) {
1235 /* The conversion failed. */
1236 }
1237
Tim Petersbdee63f2001-09-02 03:40:59 +00001238- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001239 compile but will not participate in GC. To upgrade an extension
1240 module:
1241
1242 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001243
Neil Schemenauer4042c692001-08-30 15:38:01 +00001244 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1245 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001246
Neil Schemenauer4042c692001-08-30 15:38:01 +00001247 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1248 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001249
Neil Schemenauer4042c692001-08-30 15:38:01 +00001250 - remove PyGC_HEAD_SIZE from object size calculations
1251
1252 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1253
Tim Petersbdee63f2001-09-02 03:40:59 +00001254- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001255 These can be used safely to construct string objects from a
1256 sprintf-style format string (similar to the format string supported
1257 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001258
Tim Petersedc99312001-08-22 21:36:50 +00001259New platforms
1260
Tim Petersb7da0902001-09-02 23:01:43 +00001261- Stephen Hansen contributed patches sufficient to get a clean compile
1262 under Borland C (Windows), but he reports problems running it and ran
1263 out of time to complete the port. Volunteers? Expect a MemoryError
1264 when importing the types module; this is probably shallow, and
1265 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001266
Tim Petersedc99312001-08-22 21:36:50 +00001267Tests
1268
1269Windows
1270
Tim Peters6e13a562001-09-06 00:32:15 +00001271- Large file support is now enabled on Win32 platforms as well as on
1272 Win64. This means that, for example, you can use f.tell() and f.seek()
1273 to manipulate files larger than 2 gigabytes (provided you have enough
1274 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001275 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1276 filesize limit, and large file support makes no difference there.
1277 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1278 NTFS has no practical limit on file size, and files of any size can be
1279 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001280
Tim Petersbdee63f2001-09-02 03:40:59 +00001281- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001282 points to command.com (patch from Brian Quinlan).
1283
Tim Petersedc99312001-08-22 21:36:50 +00001284
Tim Peters20f51a72001-07-21 02:31:40 +00001285What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001286Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001287===========================
1288
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001289Build
1290
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001291- Tim Peters developed a brand new Windows installer using Wise 8.1,
1292 generously donated to us by Wise Solutions.
1293
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001294- configure supports a new option --enable-unicode, with the values
1295 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1296 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001297
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001298- A new configure option --enable-framework builds a Mac OS X framework,
1299 which "make frameworkinstall" will install. This provides a starting
1300 point for more mac-like functionality, join pythonmac-sig@python.org
1301 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001302
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001303- The NeXT platform is no longer supported.
1304
1305- The `new' module is now statically linked.
1306
Tim Peters0afb6092001-08-15 06:06:44 +00001307Tools
1308
1309- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001310 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001311 the module docstring for details.
1312
Tim Peters20f51a72001-07-21 02:31:40 +00001313Tests
1314
Tim Peters5e824c32001-08-12 22:25:01 +00001315- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001316 platforms, allowing to give clearer test result output. regrtest
1317 also has optional --use/-u switch to run normally disabled tests
1318 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001319
Tim Peters20f51a72001-07-21 02:31:40 +00001320- Several new tests in the standard test suite, with special thanks to
1321 Nick Mathewson.
1322
1323Core
1324
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001325- The floor division operator // has been added as outlined in PEP
1326 238. The / operator still provides classic division (and will until
1327 Python 3.0) unless "from __future__ import division" is included, in
1328 which case the / operator will provide true division. The operator
1329 module provides truediv() and floordiv() functions. Augmented
1330 assignment variants are included, as are the equivalent overloadable
1331 methods and C API methods. See the PEP for a full discussion:
1332 <http://python.sf.net/peps/pep-0238.html>
1333
Tim Peters6cd6a822001-08-17 22:11:27 +00001334- Future statements are now effective in simulated interactive shells
1335 (like IDLE). This should "just work" by magic, but read Michael
1336 Hudson's "Future statements in simulated shells" PEP 264 for full
1337 details: <http://python.sf.net/peps/pep-0264.html>.
1338
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001339- The type/class unification (PEP 252-253) was integrated into the
1340 trunk and is not so tentative any more (the exact specification of
1341 some features is still tentative). A lot of work has done on fixing
1342 bugs and adding robustness and features (performance still has to
1343 come a long way).
1344
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001345- Warnings about a mismatch in the Python API during extension import
1346 now use the Python warning framework (which makes it possible to
1347 write filters for these warnings).
1348
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001349- A function's __dict__ (aka func_dict) will now always be a
1350 dictionary. It used to be possible to delete it or set it to None,
1351 but now both actions raise TypeErrors. It is still legal to set it
1352 to a dictionary object. Getting func.__dict__ before any attributes
1353 have been assigned now returns an empty dictionary instead of None.
1354
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001355- A new command line option, -E, was added which disables the use of
1356 all environment variables, or at least those that are specifically
1357 significant to Python. Usually those have a name starting with
1358 "PYTHON". This was used to fix a problem where the tests fail if
1359 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1360 older distribution.
1361
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001362Library
1363
Tim Peters5e824c32001-08-12 22:25:01 +00001364- New class Differ and new functions ndiff() and restore() in difflib.py.
1365 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001366 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001367
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001368- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1369 value using the minimal quoting required for the value; more
1370 reliable than using xml.sax.saxutils.escape() for attribute values.
1371
1372- Readline completion support for cmd.Cmd was added.
1373
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001374- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1375
1376- Added function threading.BoundedSemaphore()
1377
1378- Added Ka-Ping Yee's cgitb.py module.
1379
1380- The `new' module now exposes the CO_xxx flags.
1381
Martin v. Löwis560da622001-11-24 09:24:51 +00001382- The gc module offers the get_referents function.
1383
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001384New platforms
1385
1386C API
1387
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001388- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1389 which provide a cross-platform implementations for the
1390 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1391 the standard sprintf() and vsprintf() C lib APIs, these versions
1392 apply bounds checking on the used buffer which enhances protection
1393 against buffer overruns.
1394
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001395- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001396 and extensions using different Unicode widths is rendered next to
1397 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001398 will result in an ImportError. Unicode extensions writers must make
1399 sure to check the Unicode width compatibility in their extensions by
1400 using at least one of the mangled Unicode APIs in the extension.
1401
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001402- Two new flags METH_NOARGS and METH_O are available in method definition
1403 tables to simplify implementation of methods with no arguments and a
1404 single untyped argument. Calling such methods is more efficient than
1405 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1406 deprecated.
1407
Tim Petersc1731372001-08-04 08:12:36 +00001408Windows
1409
1410- "import module" now compiles module.pyw if it exists and nothing else
1411 relevant is found.
1412
Tim Peters20f51a72001-07-21 02:31:40 +00001413
Guido van Rossum55a78992001-07-17 17:22:32 +00001414What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001415Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001416===========================
1417
1418Core
Tim Petersa814db52001-05-14 07:05:58 +00001419
Tim Peters6d6c1a32001-08-02 04:15:00 +00001420- TENTATIVELY, a large amount of code implementing much of what's
1421 described in PEP 252 (Making Types Look More Like Classes) and PEP
1422 253 (Subtyping Built-in Types) was added. This will be released
1423 with Python 2.2a1. Documentation will be provided separately
1424 through http://www.python.org/2.2/. The purpose of releasing this
1425 with Python 2.2a1 is to test backwards compatibility. It is
1426 possible, though not likely, that a decision is made not to release
1427 this code as part of 2.2 final, if any serious backwards
1428 incompapatibilities are found during alpha testing that cannot be
1429 repaired.
1430
Guido van Rossum55a78992001-07-17 17:22:32 +00001431- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001432 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001433 more 'yield' statements. See PEP 255. Since this adds a new
1434 keyword to the language, this feature must be enabled by including a
1435 future statement: "from __future__ import generators" (see PEP 236).
1436 Generators will become a standard feature in a future release
1437 (probably 2.3). Without this future statement, 'yield' remains an
1438 ordinary identifier, but a warning is issued each time it is used.
1439 (These warnings currently don't conform to the warnings framework of
1440 PEP 230; we intend to fix this in 2.2a2.)
1441
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001442- The UTF-16 codec was modified to be more RFC compliant. It will now
1443 only remove BOM characters at the start of the string and then
1444 only if running in native mode (UTF-16-LE and -BE won't remove a
1445 leading BMO character).
1446
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001447- Strings now have a new method .decode() to complement the already
1448 existing .encode() method. These two methods provide direct access
1449 to the corresponding decoders and encoders of the registered codecs.
1450
1451 To enhance the usability of the .encode() method, the special
1452 casing of Unicode object return values was dropped (Unicode objects
1453 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001454
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001455 Both methods will now return whatever the codec in charge of the
1456 requested encoding returns as object, e.g. Unicode codecs will
1457 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1458 will return u"äöü"). This enables codec writer to create codecs
1459 for various simple to use conversions.
1460
1461 New codecs were added to demonstrate these new features (the .encode()
1462 and .decode() columns indicate the type of the returned objects):
1463
1464 Name | .encode() | .decode() | Description
1465 ----------------------------------------------------------------------
1466 uu | string | string | UU codec (e.g. for email)
1467 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001468 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001469 zlib | string | string | zlib compression
1470 hex | string | string | 2-byte hex codec
1471 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1472
Mark Hammond2a0af792001-05-14 03:09:36 +00001473- Some operating systems now support the concept of a default Unicode
1474 encoding for file system operations. Notably, Windows supports 'mbcs'
1475 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001476 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001477 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001478
1479 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001480 functions that return filenames (such as os.listdir()) to return Python
1481 string objects pre-encoded using the default file system encoding for
1482 the platform. As this encoding is likely to be different from Python's
1483 default encoding, converting this name to a Unicode object before passing
1484 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001485 would attempt to use its default encoding (generally ASCII) rather than
1486 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001487
Tim Petersa814db52001-05-14 07:05:58 +00001488 In general, this change simply removes surprises when working with
1489 Unicode and the file system, making these operations work as you expect,
1490 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001491 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001492
Tim Peters61dff2b2001-05-08 15:43:37 +00001493- Float (and complex) literals in source code were evaluated to full
1494 precision only when running from a .py file; the same code loaded from a
1495 .pyc (or .pyo) file could suffer numeric differences starting at about the
1496 12th significant decimal digit. For example, on a machine with IEEE-754
1497 floating arithmetic,
1498
1499 x = 9007199254740992.0
1500 print long(x)
1501
1502 printed 9007199254740992 if run directly from .py, but 9007199254740000
1503 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1504 str(float) instead of repr(float) when building code objects. marshal
1505 now uses repr(float) instead, which should reproduce floats to full
1506 machine precision (assuming the platform C float<->string I/O conversion
1507 functions are of good quality).
1508
1509 This may cause floating-point results to change in some cases, and
1510 usually for the better, but may also cause numerically unstable
1511 algorithms to break.
1512
Tim Peters2f228e72001-05-13 00:19:31 +00001513- The implementation of dicts suffers fewer collisions, which has speed
1514 benefits. However, the order in which dict entries appear in dict.keys(),
1515 dict.values() and dict.items() may differ from previous releases for a
1516 given dict. Nothing is defined about this order, so no program should
1517 rely on it. Nevertheless, it's easy to write test cases that rely on the
1518 order by accident, typically because of printing the str() or repr() of a
1519 dict to an "expected results" file. See Lib/test/test_support.py's new
1520 sortdict(dict) function for a simple way to display a dict in sorted
1521 order.
1522
Tim Peters7a3bfc32001-06-12 01:22:22 +00001523- Many other small changes to dicts were made, resulting in faster
1524 operation along the most common code paths.
1525
Guido van Rossum10315822001-05-01 20:54:30 +00001526- Dictionary objects now support the "in" operator: "x in dict" means
1527 the same as dict.has_key(x).
1528
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001529- The update() method of dictionaries now accepts generic mapping
1530 objects. Specifically the argument object must support the .keys()
1531 and __getitem__() methods. This allows you to say, for example,
1532 {}.update(UserDict())
1533
Guido van Rossum10315822001-05-01 20:54:30 +00001534- Iterators were added; this is a generalized way of providing values
1535 to a for loop. See PEP 234. There's a new built-in function iter()
1536 to return an iterator. There's a new protocol to get the next value
1537 from an iterator using the next() method (in Python) or the
1538 tp_iternext slot (in C). There's a new protocol to get iterators
1539 using the __iter__() method (in Python) or the tp_iter slot (in C).
1540 Iterating (i.e. a for loop) over a dictionary generates its keys.
1541 Iterating over a file generates its lines.
1542
Tim Petersf553f892001-05-01 20:45:31 +00001543- The following functions were generalized to work nicely with iterator
1544 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001545 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001546 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1547 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001548 join() method of strings
1549 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001550 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1551 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001552 right-hand side of assignment statements with multiple targets, such as
1553 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001554
Tim Petersd85e1022001-05-11 21:51:48 +00001555- Accessing module attributes is significantly faster (for example,
1556 random.random or os.path or yourPythonModule.yourAttribute).
1557
Tim Peterse63415e2001-05-08 04:38:29 +00001558- Comparing dictionary objects via == and != is faster, and now works even
1559 if the keys and values don't support comparisons other than ==.
1560
Tim Peters95bf9392001-05-10 08:32:44 +00001561- Comparing dictionaries in ways other than == and != is slower: there were
1562 insecurities in the dict comparison implementation that could cause Python
1563 to crash if the element comparison routines for the dict keys and/or
1564 values mutated the dicts. Making the code bulletproof slowed it down.
1565
Tim Peterseb28ef22001-06-02 05:27:19 +00001566- Collisions in dicts are resolved via a new approach, which can help
1567 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001568 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001569 faster now. Thanks to Christian Tismer for pointing out the cause and
1570 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001571
Tim Peters52e155e2001-06-16 05:42:57 +00001572- repr() is much faster for large containers (dict, list, tuple).
1573
1574
Tim Petersa814db52001-05-14 07:05:58 +00001575Library
1576
Fred Drake960fdf92001-07-20 18:38:26 +00001577- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1578 were added to the string module. These a locale-indenpendent
1579 constants, unlike letters, lowercase, and uppercase. These are now
1580 use in appropriate locations in the standard library.
1581
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001582- The flags used in dlopen calls can now be configured using
1583 sys.setdlopenflags and queried using sys.getdlopenflags.
1584
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001585- Fredrik Lundh's xmlrpclib is now a standard library module. This
1586 provides full client-side XML-RPC support. In addition,
1587 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1588 one asyncore-based). Thanks to Eric Raymond for the documentation.
1589
Guido van Rossum643d3912001-07-05 14:46:25 +00001590- The xrange() object is simplified: it no longer supports slicing,
1591 repetition, comparisons, efficient 'in' checking, the tolist()
1592 method, or the start, stop and step attributes. See PEP 260.
1593
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001594- A new function fnmatch.filter to filter lists of file names was added.
1595
Barry Warsawffd674d2001-05-22 16:00:10 +00001596- calendar.py uses month and day names based on the current locale.
1597
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001598- strop is now *really* obsolete (this was announced before with 1.6),
1599 and issues DeprecationWarning when used (except for the four items
1600 that are still imported into string.py).
1601
Tim Petersa814db52001-05-14 07:05:58 +00001602- Cookie.py now sorts key+value pairs by key in output strings.
1603
1604- pprint.isrecursive(object) didn't correctly identify recursive objects.
1605 Now it does.
1606
Tim Peters95b3f782001-05-14 18:39:41 +00001607- pprint functions now much faster for large containers (tuple, list, dict).
1608
Tim Peters7b9542a2001-06-10 23:40:19 +00001609- New 'q' and 'Q' format codes in the struct module, corresponding to C
1610 types "long long" and "unsigned long long" (on Windows, __int64). In
1611 native mode, these can be used only when the platform C compiler supports
1612 these types (when HAVE_LONG_LONG is #define'd by the Python config
1613 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001614 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1615 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001616
Guido van Rossum83213cc2001-06-12 16:48:52 +00001617- The site module installs a new built-in function 'help' that invokes
1618 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1619 it displays a message reminding the user to use 'help()' or
1620 'help(object)'.
1621
Tim Petersa814db52001-05-14 07:05:58 +00001622Tests
1623
1624- New test_mutants.py runs dict comparisons where the key and value
1625 comparison operators mutute the dicts randomly during comparison. This
1626 rapidly causes Python to crash under earlier releases (not for the faint
1627 of heart: it can also cause Win9x to freeze or reboot!).
1628
1629- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001630 pprint.isreadable() return sensible results. Also verifies that simple
1631 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001632
Tim Peters4324aa32001-05-28 22:30:08 +00001633C API
1634
1635- Removed the unused last_is_sticky argument from the internal
1636 _PyTuple_Resize(). If this affects you, you were cheating.
1637
1638
Guido van Rossum55a78992001-07-17 17:22:32 +00001639======================================================================
1640
1641
Guido van Rossumffe13be2001-04-16 18:46:45 +00001642What's New in Python 2.1 (final)?
1643=================================
1644
1645We only changed a few things since the last release candidate, all in
1646Python library code:
1647
1648- A bug in the locale module was fixed that affected locales which
1649 define no grouping for numeric formatting.
1650
1651- A few bugs in the weakref module's implementations of weak
1652 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1653 and the test suite was updated to check for these bugs.
1654
1655- An old bug in the os.path.walk() function (introduced in Python
1656 2.0!) was fixed: a non-existent file would cause an exception
1657 instead of being ignored.
1658
1659- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1660 PyChecker.
1661
1662
Guido van Rossum5b08f132001-04-16 02:05:23 +00001663What's New in Python 2.1c2?
1664===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001665
Guido van Rossum5b08f132001-04-16 02:05:23 +00001666A flurry of small changes, and one showstopper fixed in the nick of
1667time made it necessary to release another release candidate. The list
1668here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001669
Guido van Rossum5b08f132001-04-16 02:05:23 +00001670Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001671
Guido van Rossum5b08f132001-04-16 02:05:23 +00001672- Tim discovered a nasty bug in the dictionary code, caused by
1673 PyDict_Next() calling dict_resize(), and the GC code's use of
1674 PyDict_Next() violating an assumption in dict_items(). This was
1675 fixed with considerable amounts of band-aid, but the net effect is a
1676 saner and more robust implementation.
1677
1678- Made a bunch of symbols static that were accidentally global.
1679
1680Build and Ports
1681
1682- The setup.py script didn't check for a new enough version of zlib
1683 (1.1.3 is needed). Now it does.
1684
1685- Changed "make clean" target to also remove shared libraries.
1686
1687- Added a more general warning about the SGI Irix optimizer to README.
1688
1689Library
1690
1691- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1692 omitted the slash between host and file.html.
1693
1694- The mailbox module's _Mailbox class contained a completely broken
1695 and undocumented seek() method. Ripped it out.
1696
1697- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1698 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1699
1700- Fixed a few last-minute bugs in unittest.
1701
1702Extensions
1703
1704- Reverted the patch to the OpenSSL code in socketmodule.c to support
1705 RAND_status() and the EGD, and the subsequent patch that tried to
1706 fix it for pre-0.9.5 versions; the problem with the patch is that on
1707 some systems it issues a warning whenever socket is imported, and
1708 that's unacceptable.
1709
1710Tests
1711
1712- Fixed the pickle tests to work with "import test.test_pickle".
1713
1714- Tweaked test_locale.py to actually run the test Windows.
1715
1716- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1717 not "wb" (which is not a valid mode at all).
1718
1719- Fix pstats browser crashes. Import readline if it exists to make
1720 the user interface nicer.
1721
1722- Add "import thread" to the top of test modules that import the
1723 threading module (test_asynchat and test_threadedtempfile). This
1724 prevents test failures caused by a broken threading module resulting
1725 from a previously caught failed import.
1726
1727- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1728 needed on some platforms (e.g. Solaris 8) when the tests are run
1729 twice in succession.
1730
1731- Skip rather than fail test_sunaudiodev if no audio device is found.
1732
1733
1734What's New in Python 2.1c1?
1735===========================
1736
1737This list was significantly updated when 2.1c2 was released; the 2.1c1
1738release didn't mention most changes that were actually part of 2.1c1:
1739
1740Legal
1741
1742- Copyright was assigned to the Python Software Foundation (PSF) and a
1743 PSF license (very similar to the CNRI license) was added.
1744
1745- The CNRI copyright notice was updated to include 2001.
1746
1747Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001748
Guido van Rossumc9932722001-04-12 02:31:27 +00001749- After a public outcry, assignment to __debug__ is no longer illegal;
1750 instead, a warning is issued. It will become illegal in 2.2.
1751
Guido van Rossum5b08f132001-04-16 02:05:23 +00001752- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1753 "%#x" now always prepends "0x", even if the value is zero.
1754
1755- Fixed some nits in the bytecode compiler.
1756
1757- Fixed core dumps when calling certain kinds of non-functions.
1758
1759- Fixed various core dumps caused by reference count bugs.
1760
1761Build and Ports
1762
1763- Use INSTALL_SCRIPT to install script files.
1764
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001765- New port: SCO Unixware 7, by Billy G. Allie.
1766
Guido van Rossum5b08f132001-04-16 02:05:23 +00001767- Updated RISCOS port.
1768
1769- Updated BeOS port and notes.
1770
1771- Various other porting problems resolved.
1772
1773Library
1774
1775- The TERMIOS and SOCKET modules are now truly obsolete and
1776 unnecessary. Their symbols are incorporated in the termios and
1777 socket modules.
1778
1779- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1780 better tests for pickling.
1781
1782- threading: make Condition.wait() robust against KeyboardInterrupt.
1783
1784- zipfile: add support to zipfile to support opening an archive
1785 represented by an open file rather than a file name. Fix bug where
1786 the archive was not properly closed. Fixed a bug in this bugfix
1787 where flush() was called for a read-only file.
1788
1789- imputil: added an uninstall() method to the ImportManager.
1790
1791- Canvas: fixed bugs in lower() and tkraise() methods.
1792
1793- SocketServer: API change (added overridable close_request() method)
1794 so that the TCP server can explicitly close the request.
1795
1796- pstats: Eric Raymond added a simple interactive statistics browser,
1797 invoked when the module is run as a script.
1798
1799- locale: fixed a problem in format().
1800
1801- webbrowser: made it work when the BROWSER environment variable has a
1802 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1803 KDE 2. Fixed some other nits.
1804
1805- unittest: changes to allow using a different exception than
1806 AssertionError, and added a few more function aliases. Some other
1807 small changes.
1808
1809- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1810
1811- asynchat: fixed a critical bug in asynchat that slipped through the
1812 2.1b2 release. Fixed another rare bug.
1813
1814- Fix some unqualified except: clauses (always a bad code example).
1815
1816XML
1817
1818- pyexpat: new API get_version_string().
1819
1820- Fixed some minidom bugs.
1821
1822Extensions
1823
1824- Fixed a core dump in _weakref. Removed the weakref.mapping()
1825 function (it adds nothing to the API).
1826
1827- Rationalized the use of header files in the readline module, to make
1828 it compile (albeit with some warnings) with the very recent readline
1829 4.2, without breaking for earlier versions.
1830
1831- Hopefully fixed a buffering problem in linuxaudiodev.
1832
1833- Attempted a fix to make the OpenSSL support in the socket module
1834 work again with pre-0.9.5 versions of OpenSSL.
1835
1836Tests
1837
1838- Added a test case for asynchat and asyncore.
1839
1840- Removed coupling between tests where one test failing could break
1841 another.
1842
1843Tools
1844
1845- Ping added an interactive help browser to pydoc, fixed some nits
1846 in the rest of the pydoc code, and added some features to his
1847 inspect module.
1848
1849- An updated python-mode.el version 4.1 which integrates Ken
1850 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1851 much nicer in XEmacs and Emacs. When stepping through your program
1852 with pdb, in either the shell window or the *Python* window, the
1853 source file and line will be tracked by an arrow. Very cool!
1854
1855- IDLE: syntax warnings in interactive mode are changed into errors.
1856
1857- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001858 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001859
1860- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001861
Barry Warsaw11e89c72001-04-11 20:37:57 +00001862
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001863What's New in Python 2.1 beta 2?
1864================================
1865
Guido van Rossum053ae352001-03-22 14:17:21 +00001866(Unlisted are many fixed bugs, more documentation, etc.)
1867
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001868Core language, builtins, and interpreter
1869
Guido van Rossum053ae352001-03-22 14:17:21 +00001870- The nested scopes work (enabled by "from __future__ import
1871 nested_scopes") is completed; in particular, the future now extends
1872 into code executed through exec, eval() and execfile(), and into the
1873 interactive interpreter.
1874
1875- When calling a base class method (e.g. BaseClass.__init__(self)),
1876 this is now allowed even if self is not strictly spoken a class
1877 instance (e.g. when using metaclasses or the Don Beaudry hook).
1878
1879- Slice objects are now comparable but not hashable; this prevents
1880 dict[:] from being accepted but meaningless.
1881
1882- Complex division is now calculated using less braindead algorithms.
1883 This doesn't change semantics except it's more likely to give useful
1884 results in extreme cases. Complex repr() now uses full precision
1885 like float repr().
1886
1887- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1888
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001889- It is illegal to assign to the name __debug__, which is set when the
1890 interpreter starts. It is effectively a compile-time constant.
1891
1892- A warning will be issued if a global statement for a variable
1893 follows a use or assignment of that variable.
1894
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001895Standard library
1896
Guido van Rossum053ae352001-03-22 14:17:21 +00001897- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1898 inspired by JUnit), is now part of the standard library. You now
1899 have a choice of two testing frameworks: unittest requires you to
1900 write testcases as separate code, doctest gathers them from
1901 docstrings. Both approaches have their advantages and
1902 disadvantages.
1903
1904- A new module Tix was added, which wraps the Tix extension library
1905 for Tk. With that module, it is not necessary to statically link
1906 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1907 require" command. See Demo/tix/.
1908
1909- tzparse.py is now obsolete.
1910
1911- In gzip.py, the seek() and tell() methods are removed -- they were
1912 non-functional anyway, and it's better if callers can test for their
1913 existence with hasattr().
1914
1915Python/C API
1916
1917- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1918 that's already in the dictionary during a PyDict_Next() iteration.
1919 This used to fail occasionally when a dictionary resize operation
1920 could be triggered that would rehash all the keys. All other
1921 modifications to the dictionary are still off-limits during a
1922 PyDict_Next() iteration!
1923
1924- New extended APIs related to passing compiler variables around.
1925
1926- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1927 implement isinstance() and issubclass().
1928
1929- Py_BuildValue() now has a "D" conversion to create a Python complex
1930 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001931
Fred Drake4e262a92001-03-22 18:26:47 +00001932- Extensions types which support weak references must now set the
1933 field allocated for the weak reference machinery to NULL themselves;
1934 this is done to avoid the cost of checking each object for having a
1935 weakly referencable type in PyObject_INIT(), since most types are
1936 not weakly referencable.
1937
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001938- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1939 free variables and cell variables to and from the frame's f_locals.
1940
1941- Variants of several functions defined in pythonrun.h have been added
1942 to support the nested_scopes future statement. The variants all end
1943 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1944 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1945 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001946 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001947
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001948Distutils
1949
1950- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1951 into the release tree.
1952
Tim Peters0e57abf2001-05-02 07:39:38 +00001953- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001954 (an uninstaller, more customization of the installer's display)
1955
1956- from Jack Jansen: added Mac-specific code to generate a dialog for
1957 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001958 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001959 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001960
1961- added 'platforms' and 'keywords' to the set of metadata that can be
1962 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001963
1964- applied patches from Jason Tishler to make the compiler class work with
1965 Cygwin.
1966
1967
Tim Peters2fe289a2001-03-01 22:19:38 +00001968What's New in Python 2.1 beta 1?
1969================================
Tim Petersd66595f2001-02-04 03:09:53 +00001970
1971Core language, builtins, and interpreter
1972
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001973- Following an outcry from the community about the amount of code
1974 broken by the nested scopes feature introduced in 2.1a2, we decided
1975 to make this feature optional, and to wait until Python 2.2 (or at
1976 least 6 months) to make it standard. The option can be enabled on a
1977 per-module basis by adding "from __future__ import nested_scopes" at
1978 the beginning of a module (before any other statements, but after
1979 comments and an optional docstring). See PEP 236 (Back to the
1980 __future__) for a description of the __future__ statement. PEP 227
1981 (Statically Nested Scopes) has been updated to reflect this change,
1982 and to clarify the semantics in a number of endcases.
1983
1984- The nested scopes code, when enabled, has been hardened, and most
1985 bugs and memory leaks in it have been fixed.
1986
1987- Compile-time warnings are now generated for a number of conditions
1988 that will break or change in meaning when nested scopes are enabled:
1989
1990 - Using "from...import *" or "exec" without in-clause in a function
1991 scope that also defines a lambda or nested function with one or
1992 more free (non-local) variables. The presence of the import* or
1993 bare exec makes it impossible for the compiler to determine the
1994 exact set of local variables in the outer scope, which makes it
1995 impossible to determine the bindings for free variables in the
1996 inner scope. To avoid the warning about import *, change it into
1997 an import of explicitly name object, or move the import* statement
1998 to the global scope; to avoid the warning about bare exec, use
1999 exec...in... (a good idea anyway -- there's a possibility that
2000 bare exec will be deprecated in the future).
2001
2002 - Use of a global variable in a nested scope with the same name as a
2003 local variable in a surrounding scope. This will change in
2004 meaning with nested scopes: the name in the inner scope will
2005 reference the variable in the outer scope rather than the global
2006 of the same name. To avoid the warning, either rename the outer
2007 variable, or use a global statement in the inner function.
2008
Neil Schemenauera35c6882001-02-27 04:45:05 +00002009- An optional object allocator has been included. This allocator is
2010 optimized for Python objects and should be faster and use less memory
2011 than the standard system allocator. It is not enabled by default
2012 because of possible thread safety problems. The allocator is only
2013 protected by the Python interpreter lock and it is possible that some
2014 extension modules require a thread safe allocator. The object
2015 allocator can be enabled by providing the "--with-pymalloc" option to
2016 configure.
2017
Tim Petersd66595f2001-02-04 03:09:53 +00002018Standard library
2019
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002020- pyexpat now detects the expat version if expat.h defines it. A
2021 number of additional handlers are provided, which are only available
2022 since expat 1.95. In addition, the methods SetParamEntityParsing and
2023 GetInputContext of Parser objects are available with 1.95.x
2024 only. Parser objects now provide the ordered_attributes and
2025 specified_attributes attributes. A new module expat.model was added,
2026 which offers a number of additional constants if 1.95.x is used.
2027
2028- xml.dom offers the new functions registerDOMImplementation and
2029 getDOMImplementation.
2030
2031- xml.dom.minidom offers a toprettyxml method. A number of DOM
2032 conformance issues have been resolved. In particular, Element now
2033 has an hasAttributes method, and the handling of namespaces was
2034 improved.
2035
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002036- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2037 getting information about live Python code, and pydoc.py, a module
2038 for interactively converting docstrings to HTML or text.
2039 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002040 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002041 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2042 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002043
Tim Peters1eff7962001-03-01 02:31:33 +00002044- New library module difflib.py, primarily packaging the SequenceMatcher
2045 class at the heart of the popular ndiff.py file-comparison tool.
2046
2047- doctest.py (a framework for verifying Python code examples in docstrings)
2048 is now part of the std library.
2049
Tim Petersd66595f2001-02-04 03:09:53 +00002050Windows changes
2051
Guido van Rossume3955a82001-03-02 14:05:59 +00002052- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2053 small GUI that lets you browse the module docstrings using your
2054 default web browser.
2055
Tim Peters1eff7962001-03-01 02:31:33 +00002056- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2057 Platforms) is implemented. See
2058
2059 http://python.sourceforge.net/peps/pep-0235.html
2060
2061 for full details, especially the "Current Lower-Left Semantics" section.
2062 The new Windows import rules are simpler than before:
2063
2064 A. If the PYTHONCASEOK environment variable exists, same as
2065 before: silently accept the first case-insensitive match of any
2066 kind; raise ImportError if none found.
2067
2068 B. Else search sys.path for the first case-sensitive match; raise
2069 ImportError if none found.
2070
2071 The same rules have been implented on other platforms with case-
2072 insensitive but case-preserving filesystems too (including Cygwin, and
2073 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002074
Tim Peters25a9ce32001-02-19 07:06:36 +00002075- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2076 what it's supposed to do (and does do under NT and 2000) via direct
2077 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002078 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002079 all Win9x systems before.
2080
Tim Peters1eff7962001-03-01 02:31:33 +00002081- Build: Subproject _test (effectively) renamed to _testcapi.
2082
Tim Peters2fe289a2001-03-01 22:19:38 +00002083New platforms
2084
2085- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2086 Thanks to Steven Majewski!
2087
2088- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2089 Tishler!
2090
Guido van Rossum9089b272001-03-02 06:49:50 +00002091- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2092 Schwertberger! See RISCOS/README for more information -- it seems
2093 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002094 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002095
Tim Peters25a9ce32001-02-19 07:06:36 +00002096
Tim Petersd7b5e882001-01-25 03:36:26 +00002097What's New in Python 2.1 alpha 2?
2098=================================
Tim Peters40ead762001-01-27 05:35:26 +00002099
Tim Petersd7b5e882001-01-25 03:36:26 +00002100Core language, builtins, and interpreter
2101
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002102- Scopes nest. If a name is used in a function or class, but is not
2103 local, the definition in the nearest enclosing function scope will
2104 be used. One consequence of this change is that lambda statements
2105 could reference variables in the namespaces where the lambda is
2106 defined. In some unusual cases, this change will break code.
2107
2108 In all previous version of Python, names were resolved in exactly
2109 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002110 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002111 function A is defined within a function B, the names bound in B are
2112 not visible in A. The new rules make names bound in B visible in A,
2113 unless A contains a name binding that hides the binding in B.
2114
2115 Section 4.1 of the reference manual describes the new scoping rules
2116 in detail. The test script in Lib/test/test_scope.py demonstrates
2117 some of the effects of the change.
2118
2119 The new rules will cause existing code to break if it defines nested
2120 functions where an outer function has local variables with the same
2121 name as globals or builtins used by the inner function. Example:
2122
2123 def munge(str):
2124 def helper(x):
2125 return str(x)
2126 if type(str) != type(''):
2127 str = helper(str)
2128 return str.strip()
2129
2130 Under the old rules, the name str in helper() is bound to the
2131 builtin function str(). Under the new rules, it will be bound to
2132 the argument named str and an error will occur when helper() is
2133 called.
2134
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002135- The compiler will report a SyntaxError if "from ... import *" occurs
2136 in a function or class scope. The language reference has documented
2137 that this case is illegal, but the compiler never checked for it.
2138 The recent introduction of nested scope makes the meaning of this
2139 form of name binding ambiguous. In a future release, the compiler
2140 may allow this form when there is no possibility of ambiguity.
2141
Tim Peters40ead762001-01-27 05:35:26 +00002142- repr(string) is easier to read, now using hex escapes instead of octal,
2143 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2144
2145 >>> "\texample \r\n" + chr(0) + chr(255)
2146 '\texample \r\n\x00\xff' # in 2.1
2147 '\011example \015\012\000\377' # in 2.0
2148
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002149- Functions are now compared and hashed by identity, not by value, since
2150 the func_code attribute is writable.
2151
Fred Drakefb9d7122001-02-01 20:00:40 +00002152- Weak references (PEP 205) have been added. This involves a few
2153 changes in the core, an extension module (_weakref), and a Python
2154 module (weakref). The weakref module is the public interface. It
2155 includes support for "explicit" weak references, proxy objects, and
2156 mappings with weakly held values.
2157
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002158- A 'continue' statement can now appear in a try block within the body
2159 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002160 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002161
Tim Petersd7b5e882001-01-25 03:36:26 +00002162Standard library
2163
Barry Warsaw30dbd142001-01-31 22:14:01 +00002164- mailbox.py now has a new class, PortableUnixMailbox which is
2165 identical to UnixMailbox but uses a more portable scheme for
2166 determining From_ separators. Also, the constructors for all the
2167 classes in this module have a new optional `factory' argument, which
2168 is a callable used when new message classes must be instantiated by
2169 the next() method.
2170
Tim Petersd7b5e882001-01-25 03:36:26 +00002171- random.py is now self-contained, and offers all the functionality of
2172 the now-deprecated whrandom.py. See the docs for details. random.py
2173 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002174 and restoring the internal state of the generator; and jumpahead(n),
2175 for quickly forcing the internal state to be the same as if n calls to
2176 random() had been made. The latter is particularly useful for multi-
2177 threaded programs, creating one instance of the random.Random() class for
2178 each thread, then using .jumpahead() to force each instance to use a
2179 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002180
Tim Peters0de88fc2001-02-01 04:59:18 +00002181- random.py's seed() function is new. For bit-for-bit compatibility with
2182 prior releases, use the whseed function instead. The new seed function
2183 addresses two problems: (1) The old function couldn't produce more than
2184 about 2**24 distinct internal states; the new one about 2**45 (the best
2185 that can be done in the Wichmann-Hill generator). (2) The old function
2186 sometimes produced identical internal states when passed distinct
2187 integers, and there was no simple way to predict when that would happen;
2188 the new one guarantees to produce distinct internal states for all
2189 arguments in [0, 27814431486576L).
2190
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002191- The socket module now supports raw packets on Linux. The socket
2192 family is AF_PACKET.
2193
Tim Peters9ea17ac2001-02-02 05:57:15 +00002194- test_capi.py is a start at running tests of the Python C API. The tests
2195 are implemented by the new Modules/_testmodule.c.
2196
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002197- A new extension module, _symtable, provides provisional access to the
2198 internal symbol table used by the Python compiler. A higher-level
2199 interface will be added on top of _symtable in a future release.
2200
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002201- Removed the obsolete soundex module.
2202
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002203- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2204 the isSameNode method; NamedNodeMap the get method.
2205
2206- xml.sax.expatreader supports the lexical handler property; it
2207 generates comment, startCDATA, and endCDATA events.
2208
Tim Petersee826f82001-01-31 19:39:44 +00002209Windows changes
2210
2211- Build procedure: the zlib project is built in a different way that
2212 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002213 the zlib binary used. See PCbuild\readme.txt for details. Your old
2214 zlib-related directories can be deleted; you'll need to download fresh
2215 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002216
Tim Peters9ea17ac2001-02-02 05:57:15 +00002217- Build: New subproject _test for the benefit of test_capi.py (see above).
2218
Tim Petersb16c56f2001-02-02 21:24:51 +00002219- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2220 interface to some Python compiler internals).
2221
2222- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002223 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002224
Tim Petersa3a3a032000-11-30 05:22:44 +00002225What's New in Python 2.1 alpha 1?
2226=================================
2227
2228Core language, builtins, and interpreter
2229
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002230- There is a new Unicode companion to the PyObject_Str() API
2231 called PyObject_Unicode(). It behaves in the same way as the
2232 former, but assures that the returned value is an Unicode object
2233 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002234
Guido van Rossumf98eda02001-01-17 15:54:45 +00002235- The comparison operators support "rich comparison overloading" (PEP
2236 207). C extension types can provide a rich comparison function in
2237 the new tp_richcompare slot in the type object. The cmp() function
2238 and the C function PyObject_Compare() first try the new rich
2239 comparison operators before trying the old 3-way comparison. There
2240 is also a new C API PyObject_RichCompare() (which also falls back on
2241 the old 3-way comparison, but does not constrain the outcome of the
2242 rich comparison to a Boolean result).
2243
2244 The rich comparison function takes two objects (at least one of
2245 which is guaranteed to have the type that provided the function) and
2246 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2247 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2248 object, which may be NotImplemented (in which case the tp_compare
2249 slot function is used as a fallback, if defined).
2250
2251 Classes can overload individual comparison operators by defining one
2252 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002253 __ge__. There are no explicit "reflected argument" versions of
2254 these; instead, __lt__ and __gt__ are each other's reflection,
2255 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2256 reflection (similar at the C level). No other implications are
2257 made; in particular, Python does not assume that == is the Boolean
2258 inverse of !=, or that < is the Boolean inverse of >=. This makes
2259 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002260
2261 Classes or types that want to implement (in)equality tests but not
2262 the ordering operators (i.e. unordered types) should implement ==
2263 and !=, and raise an error for the ordering operators.
2264
Guido van Rossuma88479f2001-01-18 14:28:08 +00002265 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002266 Boolean; e.g. a matrix type might want to return a matrix of bits
2267 for A < B, giving elementwise comparisons. Such types should ensure
2268 that any interpretation of their value in a Boolean context raises
2269 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2270 at the C level) to always raise an exception.
2271
Guido van Rossuma88479f2001-01-18 14:28:08 +00002272- Complex numbers use rich comparisons to define == and != but raise
2273 an exception for <, <=, > and >=. Unfortunately, this also means
2274 that cmp() of two complex numbers raises an exception when the two
2275 numbers differ. Since it is not mathematically meaningful to compare
2276 complex numbers except for equality, I hope that this doesn't break
2277 too much code.
2278
Tim Peters3389f192001-02-18 08:48:49 +00002279- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002280 not defined by the language, other than that it's arbitrary but
2281 consistent (see the Reference Manual). An implementation detail changed
2282 in 2.1a1 such that None now compares less than any other object. Code
2283 relying on this new behavior (like code that relied on the previous
2284 behavior) does so at its own risk.
2285
Barry Warsaw573b5412001-01-15 20:43:18 +00002286- Functions and methods now support getting and setting arbitrarily
2287 named attributes (PEP 232). Functions have a new __dict__
2288 (a.k.a. func_dict) which hold the function attributes. Methods get
2289 and set attributes on their underlying im_func. It is a TypeError
2290 to set an attribute on a bound method.
2291
Guido van Rossum051e3352001-01-15 19:11:10 +00002292- The xrange() object implementation has been improved so that
2293 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2294 limitation that in this case len(xrange(sys.maxint)) can't be
2295 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2296 work fine as long as the index i doesn't actually reach 2**31.
2297 (Python uses regular ints for sequence and string indices; fixing
2298 that is much more work.)
2299
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002300- Two changes to from...import:
2301
Guido van Rossumba381232001-02-03 15:06:40 +00002302 1) "from M import X" now works even if (after loading module M)
2303 sys.modules['M'] is not a real module; it's basically a getattr()
2304 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002305
2306 2) "from M import *" now looks for M.__all__ to decide which names to
2307 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2308 filters out names starting with '_' as before. Whether or not
2309 __all__ exists, there's no restriction on the type of M.
2310
Guido van Rossumf61f1662001-01-10 20:13:55 +00002311- File objects have a new method, xreadlines(). This is the fastest
2312 way to iterate over all lines in a file:
2313
2314 for line in file.xreadlines():
2315 ...do something to line...
2316
2317 See the xreadlines module (mentioned below) for how to do this for
2318 other file-like objects.
2319
2320- Even if you don't use file.xreadlines(), you may expect a speedup on
2321 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002322 quite a bit in platform-specific ways: on systems (like Linux) that
2323 support flockfile(), getc_unlocked(), and funlockfile(), those are
2324 used by default. On systems (like Windows) without getc_unlocked(),
2325 a complicated (but still thread-safe) method using fgets() is used by
2326 default.
2327
Tim Petersd52269b2001-01-25 06:23:18 +00002328 You can force use of the fgets() method by #define'ing
2329 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002330 getc_unlocked()).
2331
Tim Petersd52269b2001-01-25 06:23:18 +00002332 You can force fgets() not to be used by #define'ing
2333 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002334 test_bufio.py fails -- and let us know if it does!).
2335
2336- In addition, the fileinput module, while still slower than the other
2337 methods on most platforms, has been sped up too, by using
2338 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002339
2340- Support for run-time warnings has been added, including a new
2341 command line option (-W) to specify the disposition of warnings.
2342 See the description of the warnings module below.
2343
2344- Extensive changes have been made to the coercion code. This mostly
2345 affects extension modules (which can now implement mixed-type
2346 numerical operators without having to use coercion), but
2347 occasionally, in boundary cases the coercion semantics have changed
2348 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002349 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002350 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002351 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002352
Guido van Rossumf98eda02001-01-17 15:54:45 +00002353- In connection with the coercion changes, a new built-in singleton
2354 object, NotImplemented is defined. This can be returned for
2355 operations that wish to indicate they are not implemented for a
2356 particular combination of arguments. From C, this is
2357 Py_NotImplemented.
2358
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002359- The interpreter accepts now bytecode files on the command line even
2360 if they do not have a .pyc or .pyo extension. On Linux, after executing
2361
Martin v. Löwise214baa2001-02-04 22:37:56 +00002362import imp,sys,string
2363magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2364reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2365open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002366
2367 any byte code file can be used as an executable (i.e. as an argument
2368 to execve(2)).
2369
Tim Peters9940b802000-12-01 07:59:35 +00002370- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002371 character. In 1.6 and earlier, they never produced a sign,
2372 and raised an error if the value of the long was too large
2373 to fit in a Python int. In 2.0, they produced a sign if and
2374 only if too large to fit in an int. This was inconsistent
2375 across platforms (because the size of an int varies across
2376 platforms), and inconsistent with hex() and oct(). Example:
2377
2378 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002379 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002380 'ffffffbe' # in 2.0 and before, on 32-bit machines
2381 >>> hex(-0x42L)
2382 '-0x42L' # in all versions of Python
2383
Tim Peters9940b802000-12-01 07:59:35 +00002384 The behavior of %d formats for negative Python longs remains
2385 the same as in 2.0 (although in 1.6 and before, they raised
2386 an error if the long didn't fit in a Python int).
2387
2388 %u formats don't make sense for Python longs, but are allowed
2389 and treated the same as %d in 2.1. In 2.0, a negative long
2390 formatted via %u produced a sign if and only if too large to
2391 fit in an int. In 1.6 and earlier, a negative long formatted
2392 via %u raised an error if it was too big to fit in an int.
2393
Guido van Rossum3661d392000-12-12 22:10:31 +00002394- Dictionary objects have an odd new method, popitem(). This removes
2395 an arbitrary item from the dictionary and returns it (in the form of
2396 a (key, value) pair). This can be useful for algorithms that use a
2397 dictionary as a bag of "to do" items and repeatedly need to pick one
2398 item. Such algorithms normally end up running in quadratic time;
2399 using popitem() they can usually be made to run in linear time.
2400
Tim Peters36cdad12000-12-29 02:06:45 +00002401Standard library
2402
Thomas Woutersfe385252001-01-19 23:16:56 +00002403- In the time module, the time argument to the functions strftime,
2404 localtime, gmtime, asctime and ctime is now optional, defaulting to
2405 the current time (in the local timezone).
2406
Guido van Rossumda91f222001-01-15 16:36:08 +00002407- The ftplib module now defaults to passive mode, which is deemed a
2408 more useful default given that clients are often inside firewalls
2409 these days. Note that this could break if ftplib is used to connect
2410 to a *server* that is inside a firewall, from outside; this is
2411 expected to be a very rare situation. To fix that, you can call
2412 ftp.set_pasv(0).
2413
Martin v. Löwis10a27872001-01-13 09:54:41 +00002414- The module site now treats .pth files not only for path configuration,
2415 but also supports extensions to the initialization code: Lines starting
2416 with import are executed.
2417
Guido van Rossumf61f1662001-01-10 20:13:55 +00002418- There's a new module, warnings, which implements a mechanism for
2419 issuing and filtering warnings. There are some new built-in
2420 exceptions that serve as warning categories, and a new command line
2421 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2422 turns warnings into errors). warnings.warn(message[, category])
2423 issues a warning message; this can also be called from C as
2424 PyErr_Warn(category, message).
2425
2426- A new module xreadlines was added. This exports a single factory
2427 function, xreadlines(). The intention is that this code is the
2428 absolutely fastest way to iterate over all lines in an open
2429 file(-like) object:
2430
2431 import xreadlines
2432 for line in xreadlines.xreadlines(file):
2433 ...do something to line...
2434
2435 This is equivalent to the previous the speed record holder using
2436 file.readlines(sizehint). Note that if file is a real file object
2437 (as opposed to a file-like object), this is equivalent:
2438
2439 for line in file.xreadlines():
2440 ...do something to line...
2441
Tim Peters36cdad12000-12-29 02:06:45 +00002442- The bisect module has new functions bisect_left, insort_left,
2443 bisect_right and insort_right. The old names bisect and insort
2444 are now aliases for bisect_right and insort_right. XXX_right
2445 and XXX_left methods differ in what happens when the new element
2446 compares equal to one or more elements already in the list: the
2447 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002448 right. Code that doesn't care where equal elements end up should
2449 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002450
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002451- The new curses.panel module wraps the panel library that forms part
2452 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2453
Guido van Rossumf61f1662001-01-10 20:13:55 +00002454- The SocketServer module now sets the allow_reuse_address flag by
2455 default in the TCPServer class.
2456
2457- A new function, sys._getframe(), returns the stack frame pointer of
2458 the caller. This is intended only as a building block for
2459 higher-level mechanisms such as string interpolation.
2460
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002461- The pyexpat module supports a number of new handlers, which are
2462 available only in expat 1.2. If invocation of a callback fails, it
2463 will report an additional frame in the traceback. Parser objects
2464 participate now in garbage collection. If expat reports an unknown
2465 encoding, pyexpat will try to use a Python codec; that works only
2466 for single-byte charsets. The parser type objects is exposed as
2467 XMLParserObject.
2468
2469- xml.dom now offers standard definitions for symbolic node type and
2470 exception code constants, and a hierarchy of DOM exceptions. minidom
2471 was adjusted to use them.
2472
2473- The conformance of xml.dom.minidom to the DOM specification was
2474 improved. It detects a number of additional error cases; the
2475 previous/next relationship works even when the tree is modified;
2476 Node supports the normalize() method; NamedNodeMap, DocumentType and
2477 DOMImplementation classes were added; Element supports the
2478 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2479 method.
2480
Guido van Rossumf61f1662001-01-10 20:13:55 +00002481Build issues
2482
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002483- For Unix (and Unix-compatible) builds, configuration and building of
2484 extension modules is now greatly automated. Rather than having to
2485 edit the Modules/Setup file to indicate which modules should be
2486 built and where their include files and libraries are, a
2487 distutils-based setup.py script now takes care of building most
2488 extension modules. All extension modules built this way are built
2489 as shared libraries. Only a few modules that must be linked
2490 statically are still listed in the Setup file; you won't need to
2491 edit their configuration.
2492
2493- Python should now build out of the box on Cygwin. If it doesn't,
2494 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002495
2496- Python now always uses its own (renamed) implementation of getopt()
2497 -- there's too much variation among C library getopt()
2498 implementations.
2499
2500- C++ compilers are better supported; the CXX macro is always set to a
2501 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002502
Tim Petersd92dfe02000-12-12 01:18:41 +00002503Windows changes
2504
2505- select module: By default under Windows, a select() call
2506 can specify no more than 64 sockets. Python now boosts
2507 this Microsoft default to 512. If you need even more than
2508 that, see the MS docs (you'll need to #define FD_SETSIZE
2509 and recompile Python from source).
2510
Guido van Rossumf61f1662001-01-10 20:13:55 +00002511- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2512 subdirectory is no more!
2513
Tim Petersa3a3a032000-11-30 05:22:44 +00002514
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002515What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002516=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002517
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002518Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002519changes are in the file HISTORY. If you are making the jump directly
2520from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2521HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002522
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002523Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2524the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2525http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002526
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002527--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002528
2529======================================================================
2530
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002531What's new in 2.0 (since release candidate 1)?
2532==============================================
2533
2534Standard library
2535
2536- The copy_reg module was modified to clarify its intended use: to
2537 register pickle support for extension types, not for classes.
2538 pickle() will raise a TypeError if it is passed a class.
2539
2540- Fixed a bug in gettext's "normalize and expand" code that prevented
2541 it from finding an existing .mo file.
2542
2543- Restored support for HTTP/0.9 servers in httplib.
2544
Tim Peters989b7b92000-10-16 20:24:53 +00002545- The math module was changed to stop raising OverflowError in case of
2546 underflow, and return 0 instead in underflow cases. Whether Python
2547 used to raise OverflowError in case of underflow was platform-
2548 dependent (it did when the platform math library set errno to ERANGE
2549 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002550
2551- Fixed a bug in StringIO that occurred when the file position was not
2552 at the end of the file and write() was called with enough data to
2553 extend past the end of the file.
2554
2555- Fixed a bug that caused Tkinter error messages to get lost on
2556 Windows. The bug was fixed by replacing direct use of
2557 interp->result with Tcl_GetStringResult(interp).
2558
2559- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2560 redirect response.
2561
2562- Several changes were made to distutils: Some debugging code was
2563 removed from util. Fixed the installer used when an external zip
2564 program (like WinZip) is not found; the source code for this
2565 installer is in Misc/distutils. check_lib() was modified to behave
2566 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2567 test for whether installed modules are on sys.path was changed to
2568 use both normcase() and normpath().
2569
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002570- Several minor bugs were fixed in the xml package (the minidom,
2571 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002572
2573- The regression test driver (regrtest.py) behavior when invoked with
2574 -l changed: It now reports a count of objects that are recognized as
2575 garbage but not freed by the garbage collector.
2576
Tim Peters989b7b92000-10-16 20:24:53 +00002577- The regression test for the math module was changed to test
2578 exceptional behavior when the test is run in verbose mode. Python
2579 cannot yet guarantee consistent exception behavior across platforms,
2580 so the exception part of test_math is run only in verbose mode, and
2581 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002582
2583Internals
2584
2585- PyOS_CheckStack() has been disabled on Win64, where it caused
2586 test_sre to fail.
2587
2588Build issues
2589
2590- Changed compiler flags, so that gcc is always invoked with -Wall and
2591 -Wstrict-prototypes. Users compiling Python with GCC should see
2592 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002593 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002594 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002595
Tim Petersa3a3a032000-11-30 05:22:44 +00002596- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002597
2598Tools and other miscellany
2599
2600- The compiler in Tools/compiler was updated to support the new
2601 language features introduced in 2.0: extended print statement, list
2602 comprehensions, and augmented assignments. The new compiler should
2603 also be backwards compatible with Python 1.5.2; the compiler will
2604 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002605 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002606
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002607What's new in 2.0 release candidate 1 (since beta 2)?
2608=====================================================
2609
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002610What is release candidate 1?
2611
2612We believe that release candidate 1 will fix all known bugs that we
2613intend to fix for the 2.0 final release. This release should be a bit
2614more stable than the previous betas. We would like to see even more
2615widespread testing before the final release, so we are producing this
2616release candidate. The final release will be exactly the same unless
2617any show-stopping (or brown bag) bugs are found by testers of the
2618release candidate.
2619
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002620All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002621to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002622
2623Core language, builtins, and interpreter
2624
2625- A bug that caused crashes when __coerce__ was used with augmented
2626 assignment, e.g. +=, was fixed.
2627
2628- Raise ZeroDivisionError when raising zero to a negative number,
2629 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2630 power operator and the result of math.pow(0.0, -2.0) will vary by
2631 platform. On Linux, it raises a ValueError.
2632
2633- A bug in Unicode string interpolation was fixed that occasionally
2634 caused errors with formats including "%%". For example, the
2635 following expression "%% %s" % u"abc" no longer raises a TypeError.
2636
2637- Compilation of deeply nested expressions raises MemoryError instead
2638 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2639
2640- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2641 rendering them useless. They are now written in binary mode again.
2642
2643Standard library
2644
2645- Keyword arguments are now accepted for most pattern and match object
2646 methods in SRE, the standard regular expression engine.
2647
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002648- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002649 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002650
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002651- Several bugs in the Unicode handling and error handling in _tkinter
2652 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002653
2654- Fix memory management errors in Merge() and Tkapp_Call() routines.
2655
2656- Several changes were made to cStringIO to make it compatible with
2657 the file-like object interface and with StringIO. If operations are
2658 performed on a closed object, an exception is raised. The truncate
2659 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002660 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002661
2662- There were many changes made to the linuxaudiodev module and its
2663 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002664 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002665
2666 Note that this module is named poorly, because it should work
2667 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002668 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002669
2670 The module now raises exceptions when errors occur instead of
2671 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2672 audio) and defines a getptr() method that calls the
2673 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2674
2675- The library_version attribute, introduced in an earlier beta, was
2676 removed because it can not be supported with early versions of the C
2677 readline library, which provides no way to determine the version at
2678 compile-time.
2679
2680- The binascii module is now enabled on Win64.
2681
Tim Peters46446d62000-10-09 21:19:31 +00002682- tokenize.py no longer suffers "recursion depth" errors when parsing
2683 programs with very long string literals.
2684
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002685Internals
2686
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002687- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002688 which is called when the interpreter starts up to determine where
2689 the standard library is installed. These vulnerabilities affect all
2690 previous versions of Python and can be exploited by setting very
2691 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2692 setuid Python script, although use of the wrapper in
2693 Misc/setuid-prog.c will eliminate the vulnerability.
2694
2695- Fixed garbage collection bugs in instance creation that were
2696 triggered when errors occurred during initialization. The solution,
2697 applied in cPickle and in PyInstance_New(), is to call
2698 PyObject_GC_Init() after the initialization of the object's
2699 container attributes is complete.
2700
2701- pyexpat adds definitions of PyModule_AddStringConstant and
2702 PyModule_AddObject if the Python version is less than 2.0, which
2703 provides compatibility with PyXML on Python 1.5.2.
2704
2705- If the platform has a bogus definition for LONG_BIT (the number of
2706 bits in a long), an error will be reported at compile time.
2707
2708- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2709 collection crashes and possibly other, unreported crashes.
2710
2711- Fixed a memory leak in _PyUnicode_Fini().
2712
2713Build issues
2714
2715- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002716 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002717 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002718
2719- The mmap.PAGESIZE constant is now initialized using sysconf when
2720 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2721
2722- The md5 file should now compile on all platforms.
2723
2724- The select module now compiles on platforms that do not define
2725 POLLRDNORM and related constants.
2726
2727- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002728 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002729
Jeremy Hylton10921202000-10-09 18:34:12 +00002730- BeOS: A number of changes were made to the build and installation
2731 process. ar-fake now operates on a directory of object files.
2732 dl_export.h is gone, and its macros now appear on the mwcc command
2733 line during build on PPC BeOS.
2734
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002735- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002736 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002737
2738- Cygwin: Support for shared libraries, Tkinter, and sockets.
2739
2740- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2741
2742Tools and other miscellany
2743
2744- Removed debugging prints from main used with freeze.
2745
Tim Peters46446d62000-10-09 21:19:31 +00002746- IDLE auto-indent no longer crashes when it encounters Unicode
2747 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002748
2749What's new in 2.0 beta 2 (since beta 1)?
2750========================================
2751
2752Core language, builtins, and interpreter
2753
Tim Peters482c0212000-09-26 06:33:09 +00002754- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002755 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002756
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002757- Add -h and -V command line options to print the usage message and
2758 Python version number and exit immediately.
2759
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002760- eval() and exec accept Unicode objects as code parameters.
2761
2762- getattr() and setattr() now also accept Unicode objects for the
2763 attribute name, which are converted to strings using the default
2764 encoding before lookup.
2765
2766- Multiplication on string and Unicode now does proper bounds
2767 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2768 string is too long."
2769
2770- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002771 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002772
Jeremy Hylton1b618592000-09-26 05:32:36 +00002773
2774Standard library and extensions
2775
Guido van Rossum5b08f132001-04-16 02:05:23 +00002776- socket module: the OpenSSL code now adds support for RAND_status()
2777 and EGD (Entropy Gathering Device).
2778
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002779- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002780 argument checking; it still takes no arguments.
2781
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002782- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002783
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002784- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002785
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002786- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002787
2788- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002789 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002790
2791- copy: Copy Unicode objects atomically.
2792
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002793- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002794
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002795- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002796
Fred Drake67233bc2000-09-26 16:40:27 +00002797- dbm: Add get() and setdefault() methods to dbm object. Add constant
2798 `library' to module that names the library used. Added doc strings
2799 and method names to error messages. Uses configure to determine
2800 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2801 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002802
2803- distutils: Update to version 0.9.3.
2804
2805- dl: Add several dl.RTLD_ constants.
2806
2807- fpectl: Now supported on FreeBSD.
2808
2809- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2810 found by the collector will be saved in gc.garbage. This is useful
2811 for debugging a program that creates reference cycles.
2812
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002813- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002814 of HTTP class. Do not close socket on zero-length response. Do not
2815 crash when server sends invalid content-length header.
2816
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002817- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002818
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002819- marshal: When reading a short, sign-extend on platforms where shorts
2820 are bigger than 16 bits. When reading a long, repair the unportable
2821 sign extension that was being done for 64-bit machines. (It assumed
2822 that signed right shift sign-extends.)
2823
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002824- operator: Add contains(), invert(), __invert__() as aliases for
2825 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002826
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002827- os: Add support for popen2() and popen3() on all platforms where
2828 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002829
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002830- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002831 clicking on a file in Explorer (or passing the file name to the
2832 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002833
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002834- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002835 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002836
2837- pickle: Now raises ValueError when an invalid pickle that contains
2838 a non-string repr where a string repr was expected. This behavior
2839 matches cPickle.
2840
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002841- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002842
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002843- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002844
2845- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002846 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002847 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002848
2849- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002850 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002851
2852- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002853 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002854 few cycles during startup since the first call to
2855 setdefaultencoding() will initialize the codec registry and the
2856 encodings package.
2857
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002858- socket: Support for size hint in readlines() method of object returned
2859 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002860
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002861- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002862 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002863 is followed by whitespace.
2864
Tim Petersa3a3a032000-11-30 05:22:44 +00002865- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002866
2867- struct: Check ranges for bytes and shorts.
2868
2869- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002870 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002871
2872- Tkinter: Image objects are now guaranteed to have unique ids. Set
2873 event.delta to zero if Tk version doesn't support mousewheel.
2874 Removed some debugging prints.
2875
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002876- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002877
Fred Drake67233bc2000-09-26 16:40:27 +00002878- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002879 which works around a bug in Norton AntiVirus 2000 that leads directly
2880 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002881
2882- xml: New version detection code allows PyXML to override standard
2883 XML package if PyXML version is greater than 0.6.1.
2884
Fred Drake64bb3802000-09-26 16:21:35 +00002885- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2886 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2887 tree only for nodes which are sufficiently interesting to a specific
2888 application. Does not provide the HTML-specific extensions. Still
2889 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002890
Fred Drake64bb3802000-09-26 16:21:35 +00002891- xml.sax: SAX 2 support for Python, including all the handler
2892 interfaces needed to process XML 1.0 compliant XML. Some
2893 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002894
Fred Drake64bb3802000-09-26 16:21:35 +00002895- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2896 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002897
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002898
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899C API
2900
2901- Add three new convenience functions for module initialization --
2902 PyModule_AddObject(), PyModule_AddIntConstant(), and
2903 PyModule_AddStringConstant().
2904
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002905- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002906 removed and add #error to Python.h if NULL isn't defined after
2907 #include of stdio.h.
2908
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002909- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002910 backwards compatibility (at the source level) with old extensions.
2911
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002912- A wrapper API was added for signal() and sigaction(). Instead of
2913 either function, always use PyOS_getsig() to get a signal handler
2914 and PyOS_setsig() to set one. A new convenience typedef
2915 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002916
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002917- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002918 internal data buffer and size of a string object -- or the default
2919 encoded version of a Unicode object.
2920
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002921- PyString_Size() and PyString_AsString() accept Unicode objects.
2922
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002923- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002924 exists). INT_MAX and LONG_MAX will always be defined, even if
2925 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002926
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002927- PyFloat_FromString takes a second argument, pend, that was
2928 effectively useless. It is now officially useless but preserved for
2929 backwards compatibility. If the pend argument is not NULL, *pend is
2930 set to NULL.
2931
2932- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2933 for the attribute name. See note on getattr() above.
2934
2935- A few bug fixes to argument processing for Unicode.
2936 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2937 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2938 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002939 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002940
2941- Py_BuildValue accepts B format (for bgen-generated code).
2942
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002943
Jeremy Hylton1b618592000-09-26 05:32:36 +00002944Internals
2945
2946- On Unix, fix code for finding Python installation directory so that
2947 it works when argv[0] is a relative path.
2948
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002949- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002950 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002951 rather than by generating a copy of the object.
2952
Tim Peters482c0212000-09-26 06:33:09 +00002953- Several of the internal Unicode tables are much smaller now, and
2954 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002955
Jeremy Hylton97693b02000-09-26 17:42:51 +00002956- In the garbage collector: Fixed bug in collection of tuples. Fixed
2957 bug that caused some instances to be removed from the container set
2958 while they were still live. Fixed parsing in gc.set_debug() for
2959 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002960
2961- Fixed refcount problem in instance deallocation that only occurred
2962 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2963
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002964- On Windows, getpythonregpath is now protected against null data in
2965 registry key.
2966
2967- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002968 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002969
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002970
Jeremy Hylton1b618592000-09-26 05:32:36 +00002971Build and platform-specific issues
2972
2973- Better support of GNU Pth via --with-pth configure option.
2974
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002975- Python/C API now properly exposed to dynamically-loaded extension
2976 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002977
2978- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2979 Don't define MS_SYNC to be zero when it is undefined. Added missing
2980 prototypes in posixmodule.c.
2981
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002982- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002983 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002984
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002985- Fix largefile support on older NetBSD systems and OpenBSD by adding
2986 define for TELL64.
2987
2988
2989Tools and other miscellany
2990
2991- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2992
2993- freeze: The modulefinder now works with 2.0 opcodes.
2994
Tim Petersa3a3a032000-11-30 05:22:44 +00002995- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002996 Move hackery of sys.argv until after the Tk instance has been
2997 created, which allows the application-specific Tkinter
2998 initialization to be executed if present; also pass an explicit
2999 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003000
Jeremy Hylton1b618592000-09-26 05:32:36 +00003001
3002What's new in 2.0 beta 1?
3003=========================
3004
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003005Source Incompatibilities
3006------------------------
3007
3008None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3009such as single-argument append(), connect() and bind(), and changes to
3010str(long) and repr(float).
3011
3012
3013Binary Incompatibilities
3014------------------------
3015
3016- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3017with Python 2.0; these extensions will have to be rebuilt for Python
30182.0.
3019
3020- On Windows, attempting to import a third party extension built for
3021Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3022can do about this. Check your PYTHONPATH environment variable!
3023
3024- Python bytecode files (*.pyc and *.pyo) are not compatible between
3025releases.
3026
3027
3028Overview of Changes Since 1.6
3029-----------------------------
3030
3031There are many new modules (including brand new XML support through
3032the xml package, and i18n support through the gettext module); a list
3033of all new modules is included below. Lots of bugs have been fixed.
3034
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003035The process for making major new changes to the language has changed
3036since Python 1.6. Enhancements must now be documented by a Python
3037Enhancement Proposal (PEP) before they can be accepted.
3038
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003039There are several important syntax enhancements, described in more
3040detail below:
3041
3042 - Augmented assignment, e.g. x += 1
3043
3044 - List comprehensions, e.g. [x**2 for x in range(10)]
3045
3046 - Extended import statement, e.g. import Module as Name
3047
3048 - Extended print statement, e.g. print >> file, "Hello"
3049
3050Other important changes:
3051
3052 - Optional collection of cyclical garbage
3053
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003054Python Enhancement Proposal (PEP)
3055---------------------------------
3056
3057PEP stands for Python Enhancement Proposal. A PEP is a design
3058document providing information to the Python community, or describing
3059a new feature for Python. The PEP should provide a concise technical
3060specification of the feature and a rationale for the feature.
3061
3062We intend PEPs to be the primary mechanisms for proposing new
3063features, for collecting community input on an issue, and for
3064documenting the design decisions that have gone into Python. The PEP
3065author is responsible for building consensus within the community and
3066documenting dissenting opinions.
3067
3068The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003069
3070Augmented Assignment
3071--------------------
3072
3073This must have been the most-requested feature of the past years!
3074Eleven new assignment operators were added:
3075
Guido van Rossume905e952000-09-05 12:42:46 +00003076 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003077
3078For example,
3079
3080 A += B
3081
3082is similar to
3083
3084 A = A + B
3085
3086except that A is evaluated only once (relevant when A is something
3087like dict[index].attr).
3088
3089However, if A is a mutable object, A may be modified in place. Thus,
3090if A is a number or a string, A += B has the same effect as A = A+B
3091(except A is only evaluated once); but if a is a list, A += B has the
3092same effect as A.extend(B)!
3093
3094Classes and built-in object types can override the new operators in
3095order to implement the in-place behavior; the not-in-place behavior is
3096used automatically as a fallback when an object doesn't implement the
3097in-place behavior. For classes, the method name is derived from the
3098method name for the corresponding not-in-place operator by inserting
3099an 'i' in front of the name, e.g. __iadd__ implements in-place
3100__add__.
3101
3102Augmented assignment was implemented by Thomas Wouters.
3103
3104
3105List Comprehensions
3106-------------------
3107
3108This is a flexible new notation for lists whose elements are computed
3109from another list (or lists). The simplest form is:
3110
3111 [<expression> for <variable> in <sequence>]
3112
Guido van Rossum56db0952000-09-06 23:34:25 +00003113For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003114This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003115
3116You can also add a condition:
3117
3118 [<expression> for <variable> in <sequence> if <condition>]
3119
3120For example, [w for w in words if w == w.lower()] would yield the list
3121of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003122than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003123
3124You can also have nested for loops and more than one 'if' clause. For
3125example, here's a function that flattens a sequence of sequences::
3126
3127 def flatten(seq):
3128 return [x for subseq in seq for x in subseq]
3129
3130 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3131
3132This prints
3133
3134 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3135
3136List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003137Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003138
3139
3140Extended Import Statement
3141-------------------------
3142
3143Many people have asked for a way to import a module under a different
3144name. This can be accomplished like this:
3145
3146 import foo
3147 bar = foo
3148 del foo
3149
3150but this common idiom gets old quickly. A simple extension of the
3151import statement now allows this to be written as follows:
3152
3153 import foo as bar
3154
3155There's also a variant for 'from ... import':
3156
3157 from foo import bar as spam
3158
3159This also works with packages; e.g. you can write this:
3160
3161 import test.regrtest as regrtest
3162
3163Note that 'as' is not a new keyword -- it is recognized only in this
3164context (this is only possible because the syntax for the import
3165statement doesn't involve expressions).
3166
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003167Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003168
3169
3170Extended Print Statement
3171------------------------
3172
3173Easily the most controversial new feature, this extension to the print
3174statement adds an option to make the output go to a different file
3175than the default sys.stdout.
3176
3177For example, to write an error message to sys.stderr, you can now
3178write:
3179
3180 print >> sys.stderr, "Error: bad dog!"
3181
3182As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003183evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003184
3185 print >> None, "Hello world"
3186
3187is equivalent to
3188
3189 print "Hello world"
3190
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003191Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003192
3193
3194Optional Collection of Cyclical Garbage
3195---------------------------------------
3196
3197Python is now equipped with a garbage collector that can hunt down
3198cyclical references between Python objects. It's no replacement for
3199reference counting; in fact, it depends on the reference counts being
3200correct, and decides that a set of objects belong to a cycle if all
3201their reference counts can be accounted for from their references to
3202each other. This devious scheme was first proposed by Eric Tiedemann,
3203and brought to implementation by Neil Schemenauer.
3204
3205There's a module "gc" that lets you control some parameters of the
3206garbage collection. There's also an option to the configure script
3207that lets you enable or disable the garbage collection. In 2.0b1,
3208it's on by default, so that we (hopefully) can collect decent user
3209experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003210performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003211off by default in the final 2.0 release.
3212
3213
3214Smaller Changes
3215---------------
3216
3217A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3218map(None, seq1, seq2, ...) when the sequences have the same length;
3219i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3220the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003221zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003222
3223sys.version_info is a tuple (major, minor, micro, level, serial).
3224
3225Dictionaries have an odd new method, setdefault(key, default).
3226dict.setdefault(key, default) returns dict[key] if it exists; if not,
3227it sets dict[key] to default and returns that value. Thus:
3228
3229 dict.setdefault(key, []).append(item)
3230
3231does the same work as this common idiom:
3232
3233 if not dict.has_key(key):
3234 dict[key] = []
3235 dict[key].append(item)
3236
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003237There are two new variants of SyntaxError that are raised for
3238indentation-related errors: IndentationError and TabError.
3239
3240Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3241escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003242
3243The limits on the size of expressions and file in Python source code
3244have been raised from 2**16 to 2**32. Previous versions of Python
3245were limited because the maximum argument size the Python VM accepted
3246was 2**16. This limited the size of object constructor expressions,
3247e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3248limit was raised thanks to a patch by Charles Waldman that effectively
3249fixes the problem. It is now much more likely that you will be
3250limited by available memory than by an arbitrary limit in Python.
3251
3252The interpreter's maximum recursion depth can be modified by Python
3253programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3254limit is the maximum number of recursive calls that can be made by
3255Python code. The limit exists to prevent infinite recursion from
3256overflowing the C stack and causing a core dump. The default value is
32571000. The maximum safe value for a particular platform can be found
3258by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003259
3260New Modules and Packages
3261------------------------
3262
3263atexit - for registering functions to be called when Python exits.
3264
3265imputil - Greg Stein's alternative API for writing custom import
3266hooks.
3267
3268pyexpat - an interface to the Expat XML parser, contributed by Paul
3269Prescod.
3270
3271xml - a new package with XML support code organized (so far) in three
3272subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3273would fill a volume. There's a special feature whereby a
3274user-installed package named _xmlplus overrides the standard
3275xmlpackage; this is intended to give the XML SIG a hook to distribute
3276backwards-compatible updates to the standard xml package.
3277
3278webbrowser - a platform-independent API to launch a web browser.
3279
3280
Guido van Rossume905e952000-09-05 12:42:46 +00003281Changed Modules
3282---------------
3283
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003284array -- new methods for array objects: count, extend, index, pop, and
3285remove
3286
3287binascii -- new functions b2a_hex and a2b_hex that convert between
3288binary data and its hex representation
3289
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003290calendar -- Many new functions that support features including control
3291over which day of the week is the first day, returning strings instead
3292of printing them. Also new symbolic constants for days of week,
3293e.g. MONDAY, ..., SUNDAY.
3294
3295cgi -- FieldStorage objects have a getvalue method that works like a
3296dictionary's get method and returns the value attribute of the object.
3297
3298ConfigParser -- The parser object has new methods has_option,
3299remove_section, remove_option, set, and write. They allow the module
3300to be used for writing config files as well as reading them.
3301
3302ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003303optionally support the RFC 959 REST command.
3304
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003305gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003306
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003307httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3308the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003309
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003310locale -- implement getdefaultlocale for Win32 and Macintosh
3311
3312marshal -- no longer dumps core when marshaling deeply nested or
3313recursive data structures
3314
3315os -- new functions isatty, seteuid, setegid, setreuid, setregid
3316
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003317os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3318support under Unix.
3319
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003320os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003321
3322os.path -- fix semantics of os.path.commonprefix
3323
3324smtplib -- support for sending very long messages
3325
3326socket -- new function getfqdn()
3327
3328readline -- new functions to read, write and truncate history files.
3329The readline section of the library reference manual contains an
3330example.
3331
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003332select -- add interface to poll system call
3333
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003334shutil -- new copyfileobj function
3335
3336SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3337HTTP server.
3338
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003339Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003340
3341urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003342e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003343
3344whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003345
3346
3347Obsolete Modules
3348----------------
3349
3350None. However note that 1.6 made a whole slew of modules obsolete:
3351stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3352poly, zmod, strop, util, whatsound.
3353
3354
3355Changed, New, Obsolete Tools
3356----------------------------
3357
Tim Peters8b092332000-09-05 20:15:25 +00003358None.
Guido van Rossume905e952000-09-05 12:42:46 +00003359
3360
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003361C-level Changes
3362---------------
3363
3364Several cleanup jobs were carried out throughout the source code.
3365
3366All C code was converted to ANSI C; we got rid of all uses of the
3367Py_PROTO() macro, which makes the header files a lot more readable.
3368
3369Most of the portability hacks were moved to a new header file,
3370pyport.h; several other new header files were added and some old
3371header files were removed, in an attempt to create a more rational set
3372of header files. (Few of these ever need to be included explicitly;
3373they are all included by Python.h.)
3374
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003375Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003376and Win64, especially for the new Intel Itanium processor. Mick also
3377added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003378
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003379The C APIs to return an object's size have been update to consistently
3380use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3381previous versions, the abstract interfaces used PyXXX_Length and the
3382concrete interfaces used PyXXX_Size. The old names,
3383e.g. PyObject_Length, are still available for backwards compatibility
3384at the API level, but are deprecated.
3385
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003386The PyOS_CheckStack function has been implemented on Windows by
3387Fredrik Lundh. It prevents Python from failing with a stack overflow
3388on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003389
3390The GC changes resulted in creation of two new slots on object,
3391tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003392the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003393
3394The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003395C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003396
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003397PyErr_Format has been updated to automatically calculate the size of
3398the buffer needed to hold the formatted result string. This change
3399prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003400
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003401New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003402
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003403PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3404that are the same as their non-Ex counterparts except they take an
3405extra flag argument that tells them to close the file when done.
3406
3407XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003408
Tim Peters8b092332000-09-05 20:15:25 +00003409
3410Windows Changes
3411---------------
3412
3413New popen2/popen3/peopen4 in os module (see Changed Modules above).
3414
3415os.popen is much more usable on Windows 95 and 98. See Microsoft
3416Knowledge Base article Q150956. The Win9x workaround described there
3417is implemented by the new w9xpopen.exe helper in the root of your
3418Python installation. Note that Python uses this internally; it is not
3419a standalone program.
3420
3421Administrator privileges are no longer required to install Python
3422on Windows NT or Windows 2000. If you have administrator privileges,
3423Python's registry info will be written under HKEY_LOCAL_MACHINE.
3424Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003425under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003426uses of Python, but will prevent some advanced uses from working
3427(for example, running a Python script as an NT service, or possibly
3428from CGI).
3429
3430[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3431installer; instead, it installs the needed Tcl/Tk files directly in the
3432Python directory. If you already have a Tcl/Tk installation, this
3433wastes some disk space (about 4 Megs) but avoids problems with
3434conflicting Tcl/Tk installations, and makes it much easier for Python
3435to ensure that Tcl/Tk can find all its files.
3436
3437[This was new in 1.6] The Windows installer now installs by default in
3438\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3439
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003440
3441Updates to the changes between 1.5.2 and 1.6
3442--------------------------------------------
3443
3444The 1.6 NEWS file can't be changed after the release is done, so here
3445is some late-breaking news:
3446
3447New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3448and changes to getlocale() and setlocale().
3449
3450The new module is now enabled per default.
3451
3452It is not true that the encodings codecs cannot be used for normal
3453strings: the string.encode() (which is also present on 8-bit strings
3454!) allows using them for 8-bit strings too, e.g. to convert files from
3455cp1252 (Windows) to latin-1 or vice-versa.
3456
3457Japanese codecs are available from Tamito KAJIYAMA:
3458http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3459
3460
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003461======================================================================