blob: 2004456c17912ac83993b7da3b050c618f5daeb1 [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
Guido van Rossum2e4e0262002-06-04 05:58:34 +00009- The constructor for the module type now requires a name argument and
10 takes an optional docstring argument. Previously, this constructor
11 ignored its arguments. As a consequence, deriving a class from a
12 module (not from the module type) is now illegal; previously this
13 created an unnamed module, just like invoking the module type did.
14 [SF bug 563060]
15
Neal Norwitzd68f5172002-05-29 15:54:55 +000016- A new warning PendingDeprecationWarning was added to provide
17 direction on features which are in the process of being deprecated.
18 The warning will not be printed by default. To see the pending
19 deprecations, use -Walways::PendingDeprecationWarning::
20 as a command line option or warnings.filterwarnings() in code.
21
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000022- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000023 for 'str' and 'unicode', and can be used instead of
24 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000025 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000026 is an abstract base class and cannot be instantiated directly.
27
Fred Draked0ba6362002-05-02 21:28:26 +000028- Deprecated features of xrange objects have been removed as
29 promised. The start, stop, and step attributes and the tolist()
30 method no longer exist. xrange repetition and slicing have been
31 removed.
32
Guido van Rossum7dab2422002-04-26 19:40:56 +000033- New builtin function enumerate(x), from PEP 279. Example:
34 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
35 The argument can be an arbitrary iterable object.
36
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000037- The assert statement no longer tests __debug__ at runtime. This means
38 that assert statements cannot be disabled by assigning a false value
39 to __debug__.
40
Walter Dörwald068325e2002-04-15 13:36:47 +000041- A method zfill() was added to str and unicode, that fills a numeric
42 string to the left with zeros. For example,
43 "+123".zfill(6) -> "+00123".
44
Guido van Rossum862fe3c2002-04-15 12:36:47 +000045- Complex numbers supported divmod() and the // and % operators, but
46 these make no sense. Since this was documented, they're being
47 deprecated now.
48
Guido van Rossum26dd8302002-04-26 20:11:29 +000049- String and unicode methods lstrip(), rstrip() and strip() now take
50 an optional argument that specifies the characters to strip. For
51 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000052
Guido van Rossumc69343b2002-04-12 19:22:48 +000053- Added a new dict method pop(key). This removes and returns the
54 value corresponding to key. [SF patch #539949]
55
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000056- Changed new-style class instantiation so that when C's __new__
57 method returns something that's not a C instance, its __init__ is
58 not called. [SF bug #537450]
59
Guido van Rossum181e41a2002-04-06 00:23:25 +000060- Fixed super() to work correctly with class methods. [SF bug #535444]
61
Guido van Rossum47834462002-04-04 15:21:33 +000062- A new built-in type, bool, has been added, as well as built-in
63 names for its two values, True and False. Comparisons and sundry
64 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000065 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000066 is backward compatible.
67
Guido van Rossum95b62a62002-03-29 01:07:24 +000068- Fixed two bugs reported as SF #535905: under certain conditions,
69 deallocating a deeply nested structure could cause a segfault in the
70 garbage collector, due to interaction with the "trashcan" code;
71 access to the current frame during destruction of a local variable
72 could access a pointer to freed memory.
73
Neil Schemenauer9d50d132002-03-22 17:06:59 +000074- The optional object allocator has been enabled by default.
75
Guido van Rossum8c842552002-03-14 23:05:54 +000076- If you try to pickle an instance of a class that has __slots__ but
77 doesn't define or override __getstate__, a TypeError is now raised.
78 This is done by adding a bozo __getstate__ to the class that always
79 raises TypeError. (Before, this would appear to be pickled, but the
80 state of the slots would be lost.)
81
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000082- PyErr_Display will provide file and line information for all exceptions
83 that have an attribute print_file_and_line, not just SyntaxErrors.
84
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000085- The UTF-8 codec will now encode and decode Unicode surrogates
86 correctly and without raising exceptions for unpaired ones.
87
Neal Norwitz649b7592002-01-01 19:07:13 +000088- file.xreadlines() now raises a ValueError if the file is closed:
89 Previously, an xreadlines object was returned which would raise
90 a ValueError when the xreadlines.next() method was called.
91
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000092- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +000093 An exception will now be raised if more than one argument is used.
94
Tim Petersaf8446f2001-12-21 21:36:50 +000095Extension modules
96
Tim Peters81b92512002-04-29 01:37:32 +000097- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +000098 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +000099 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000100
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000101- posix.killpg and posix.mknod have been added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000102
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000103- The locale module now exposes the C library's gettext interface.
104
Tim Petersfbf74f22002-03-14 19:06:01 +0000105- A security hole ("double free") was found in zlib-1.1.3, a popular
106 third party compression library used by some Python modules. The
107 hole was quickly plugged in zlib-1.1.4, and the Windows build of
108 Python now ships with zlib-1.1.4.
109
Martin v. Löwis688357e2002-04-08 21:28:20 +0000110- pwd, grp, and resource return enhanced tuples now, with symbolic
111 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000112
Martin v. Löwis99866332002-03-01 10:27:01 +0000113- array.array is now a type object. A new format character
114 'u' indicates Py_UNICODE arrays. For those, .tounicode and
115 .fromunicode methods are available. Arrays now support __iadd__
116 and __imul__.
117
Neal Norwitze790eae2002-01-01 21:14:12 +0000118- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000119 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
120 is called.
121
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000122- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
123 been added where available.
124
Tim Petersaf8446f2001-12-21 21:36:50 +0000125Library
126
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000127- Stop using strings for exceptions. String objects used for exceptions
128 now derive from Exception. The objects changed were: Tkinter.TclError,
129 bdb.BdbQuit, macpath.norm_error, tabnanny.NannyNag, and xdrlib.Error.
130
Walter Dörwald474458d2002-06-04 15:16:29 +0000131- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
132 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
133 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
134 big endian systems were added to the codecs module. The old names
135 BOM32_* and BOM64_* were off by a factor of 2.
136
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000137- added degree/radian conversion functions to the math module.
138
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000139- ftplib.retrlines() now tests for callback is None rather than testing
140 for False. Was causing an error when given a callback object which
141 was callable but also returned len() as zero. The change may
142 create new breakage if the caller relied on the undocumented behavior
143 and called with callback set to [] or some other False value not
144 identical to None.
145
Tim Peters46c04e12002-05-05 20:40:00 +0000146- random.gauss() uses a piece of hidden state used by nothing else,
147 and the .seed() and .whseed() methods failed to reset it. In other
148 words, setting the seed didn't completely determine the sequence of
149 results produced by random.gauss(). It does now. Programs repeatedly
150 mixing calls to a seed method with calls to gauss() may see different
151 results now.
152
Fred Drake7f781c92002-05-01 20:33:53 +0000153- The pickle.Pickler class grew a clear_memo() method to mimic that
154 provided by cPickle.Pickler.
155
Tim Peters81b92512002-04-29 01:37:32 +0000156- difflib's SequenceMatcher class now does a dynamic analysis of
157 which elements are so frequent as to constitute noise. For
158 comparing files as sequences of lines, this generally works better
159 than the IS_LINE_JUNK function, and function ndiff's linejunk
160 argument defaults to None now as a result. A happy benefit is
161 that SequenceMatcher may run much faster now when applied
162 to large files with many duplicate lines (for example, C program
163 text with lots of repeated "}" and "return NULL;" lines).
164
Guido van Rossum256705b2002-04-23 13:29:43 +0000165- New Text.dump() method in Tkinter module.
166
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000167- New distutils commands for building packagers were added to
168 support pkgtool on Solaris and swinstall on HP-UX.
169
170- distutils now has a new abstract binary packager base class
171 command/bdist_packager, which simplifies writing packagers.
172 This will hopefully provide the missing bits to encourage
173 people to submit more packagers, e.g. for Debian, FreeBSD
174 and other systems.
175
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000176- The UTF-16, -LE and -BE now raise a NotImplementedError
177 for all calls to .readline(). Previously, they used to just
178 produce garbage or fail with an encoding error -- UTF-16 is
179 a 2-byte encoding and the C lib's line reading APIs don't
180 work well with these.
181
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000182- compileall now supports quiet operation.
183
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000184- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000185 connections.
186
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000187- socket module: the SSL support was broken out of the main
188 _socket module C helper and placed into a new _ssl helper
189 which now gets imported by socket.py if available and working.
190
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000191- encodings package: added aliases for all supported IANA character
192 sets
193
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000194- ftplib: to safeguard the user's privacy, anonymous login will use
195 "anonymous@" as default password, rather than the real user and host
196 name.
197
Fred Drake36736122002-01-10 13:50:31 +0000198- webbrowser: tightened up the command passed to os.system() so that
199 arbitrary shell code can't be executed because a bogus URL was
200 passed in.
201
Tim Peters11bd9942002-02-01 00:52:29 +0000202- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000203 gettext.find an optional all argument. Translations will now fallback
204 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000205
Martin v. Löwis9668b932002-01-12 11:27:42 +0000206- distutils bdist commands now offer a --skip-build option.
207
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000208- warnings.warn now accepts a Warning instance as first argument.
209
Fred Drakefed7e852002-04-04 19:36:15 +0000210- The xml.sax.expatreader.ExpatParser class will no longer create
211 circular references by using itself as the locator that gets passed
212 to the content handler implementation. [SF bug #535474]
213
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000214- The email.Parser.Parser class now properly parses strings regardless
215 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
216 or CRLF). Also, the Header class's constructor default arguments
217 has changed slightly so that an explicit maxlinelen value is always
218 honored.
219
Tim Petersaf8446f2001-12-21 21:36:50 +0000220Tools/Demos
221
Marc-André Lemburg46260092002-04-04 16:17:11 +0000222- freeze.py now produces binaries which can import shared modules,
223 unlike before when this failed due to missing symbol exports in
224 the generated binary.
225
Tim Petersaf8446f2001-12-21 21:36:50 +0000226Build
227
Tim Peters639295f2002-04-21 07:30:30 +0000228- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
229 say how or when to configure it, or how to turn it off.
230
Martin v. Löwis1142de32002-03-29 16:28:31 +0000231- On Unix, a shared libpython2.3.so can be created with --enable-shared.
232
Tim Peters8deda702002-03-30 10:06:07 +0000233- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
234 preprocessor symbols were eliminated. The internal decisions they
235 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000236
Fred Drake7d28b732002-05-02 21:17:00 +0000237- The tools used to build the documentation now work under Cygwin as
238 well as Unix.
239
Tim Petersaf8446f2001-12-21 21:36:50 +0000240C API
241
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000242- Added new macro PySequence_ITEM(o, i) that directly calls
243 sq_item without rechecking that o is a sequence and without
244 adjusting for negative indices.
245
Fred Draked0ba6362002-05-02 21:28:26 +0000246- PyRange_New() now raises ValueError if the fourth argument is not 1.
247 This is part of the removal of deprecated features of the xrange
248 object.
249
Guido van Rossum517c7d42002-04-26 02:49:14 +0000250- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
251 coercion if both arguments have the same type but this type has the
252 CHECKTYPES flag set. This is to better support proxies.
253
Neil Schemenauer9344b142002-04-12 23:00:08 +0000254- The type of tp_free has been changed from "void (*)(PyObject *)" to
255 "void (*)(void *)".
256
257- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
258
Guido van Rossum0986d822002-04-08 01:38:42 +0000259- A type can now inherit its metatype from its base type. Previously,
260 when PyType_Ready() was called, if ob_type was found to be NULL, it
261 was always set to &PyType_Type; now it is set to base->ob_type,
262 where base is tp_base, defaulting to &PyObject_Type.
263
264- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
265
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000266- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000267
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000268- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000269 without going through the buffer API.
270
Martin v. Löwis7198a522002-01-01 19:59:11 +0000271- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
272
Tim Peters10a3bb52001-12-25 19:07:38 +0000273- An old #define of ANY as void has been removed from pyport.h. This
274 hasn't been used since Python's pre-ANSI days, and the #define has
275 been marked as obsolete since then. SF bug 495548 says it created
276 conflicts with other packages, so keeping it around wasn't harmless.
277
Tim Petersaf8446f2001-12-21 21:36:50 +0000278- Because Python's magic number scheme broke on January 1st, we decided
279 to stop Python development. Thanks for all the fish!
280
Tim Petersfb05db22002-03-11 00:24:00 +0000281- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000282 scheme to a new one. See Python/import.c for details.
283
Tim Petersaf8446f2001-12-21 21:36:50 +0000284New platforms
285
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000286- GNU/Hurd is now supported.
287
Tim Petersaf8446f2001-12-21 21:36:50 +0000288Tests
289
290Windows
291
Tim Peters08e72952002-04-16 20:48:01 +0000292- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
293 of that has been fixed in the installer (disabled Wise's "delete in-
294 use files" uninstall option).
295
Guido van Rossum181e41a2002-04-06 00:23:25 +0000296- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
297
Tim Peters33187922002-04-04 20:02:04 +0000298- The installer now installs Start menu shortcuts under (the local
299 equivalent of) "All Users" when doing an Admin install.
300
Tim Petersfb05db22002-03-11 00:24:00 +0000301- file.truncate([newsize]) now works on Windows for all newsize values.
302 It used to fail if newsize didn't fit in 32 bits, reflecting a
303 limitation of MS _chsize (which is no longer used).
304
Tim Petersab034fa2002-02-01 11:27:43 +0000305- os.waitpid() is now implemented for Windows, and can be used to block
306 until a specified process exits. This is similar to, but not exactly
307 the same as, os.waitpid() on POSIX systems. If you're waiting for
308 a specific process whose pid was obtained from one of the spawn()
309 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000310 See the docs for details. The docs were changed to clarify that
311 spawn functions return, and waitpid requires, a process handle on
312 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000313
Tim Peters11bd9942002-02-01 00:52:29 +0000314- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000315 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000316 to a nasty problem: before 2.3, if you got a temp file on Windows, it
317 got wrapped in an object whose close() method first closed the
318 underlying file, then deleted the file. This usually worked fine.
319 However, the spawn family of functions on Windows create (at a low C
320 level) the same set of open files in the spawned process Q as were
321 open in the spawning process P. If a temp file f was among them, then
322 doing f.close() in P first closed P's C-level file handle on f, but Q's
323 C-level file handle on f remained open, so the attempt in P to delete f
324 blew up with a "Permission denied" error (Windows doesn't allow
325 deleting open files). This was surprising, subtle, and difficult to
326 work around.
327
328- The os module now exports all the symbolic constants usable with the
329 low-level os.open() on Windows: the new constants in 2.3 are
330 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
331 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
332 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
333 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
334 (so specify both if you want both; note that neither is useful unless
335 specified with O_CREAT too).
336
Tim Petersaf8446f2001-12-21 21:36:50 +0000337Mac
338
339
Tim Peters909c0912001-12-14 23:16:18 +0000340What's New in Python 2.2 final?
341Release date: 21-Dec-2001
342===============================
343
344Type/class unification and new-style classes
345
Barry Warsaw52acb492001-12-21 20:04:22 +0000346- pickle.py, cPickle: allow pickling instances of new-style classes
347 with a custom metaclass.
348
Tim Peters909c0912001-12-14 23:16:18 +0000349Core and builtins
350
Barry Warsaw52acb492001-12-21 20:04:22 +0000351- weakref proxy object: when comparing, unwrap both arguments if both
352 are proxies.
353
Tim Peters909c0912001-12-14 23:16:18 +0000354Extension modules
355
Barry Warsaw52acb492001-12-21 20:04:22 +0000356- binascii.b2a_base64(): fix a potential buffer overrun when encoding
357 very short strings.
358
359- cPickle: the obscure "fast" mode was suspected of causing stack
360 overflows on the Mac. Hopefully fixed this by setting the recursion
361 limit much smaller. If the limit is too low (it only affects
362 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
363 when compiling cPickle.c (or in pyconfig.h).
364
Tim Peters909c0912001-12-14 23:16:18 +0000365Library
366
Barry Warsaw52acb492001-12-21 20:04:22 +0000367- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
368 close or delete time).
369
370- rfc822.py: fixed a bug where the address '<>' was converted to None
371 instead of an empty string (also fixes the email.Utils module).
372
373- xmlrpclib.py: version 1.0.0; uses precision for doubles.
374
375- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000376 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000377
Tim Peters909c0912001-12-14 23:16:18 +0000378Tools/Demos
379
380Build
381
382C API
383
384New platforms
385
386Tests
387
388Windows
389
Barry Warsaw52acb492001-12-21 20:04:22 +0000390- distutils package: fixed broken Windows installers (bdist_wininst).
391
392- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
393 instances are deleted at process exit time.
394
395- socket.py: prevent mysterious warnings when socket instances are
396 deleted at process exit time.
397
398- posixmodule.c: fix a Windows crash with stat() of a filename ending
399 in backslash.
400
Tim Peters909c0912001-12-14 23:16:18 +0000401Mac
402
Barry Warsaw52acb492001-12-21 20:04:22 +0000403- The Carbon toolbox modules have been upgraded to Universal Headers
404 3.4, and experimental CoreGraphics and CarbonEvents modules have
405 been added. All only for framework-enabled MacOSX.
406
Tim Peters909c0912001-12-14 23:16:18 +0000407
Tim Peters6272dfd2001-12-13 19:34:00 +0000408What's New in Python 2.2c1?
409Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000410===========================
411
412Type/class unification and new-style classes
413
Barry Warsaw06557452001-12-14 20:47:12 +0000414- Guido's tutorial introduction to the new type/class features has
415 been extensively updated. See
416
417 http://www.python.org/2.2/descrintro.html
418
419 That remains the primary documentation in this area.
420
Guido van Rossum33bab012001-12-05 22:45:48 +0000421- Fixed a leak: instance variables declared with __slots__ were never
422 deleted!
423
Guido van Rossum4b800852001-12-03 00:54:52 +0000424- The "delete attribute" method of descriptor objects is called
425 __delete__, not __del__. In previous releases, it was mistakenly
426 called __del__, which created an unfortunate overloading condition
427 with finalizers. (The "get attribute" and "set attribute" methods
428 are still called __get__ and __set__, respectively.)
429
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000430- Some subtle issues with the super built-in were fixed:
431
432 (a) When super itself is subclassed, its __get__ method would still
433 return an instance of the base class (i.e., of super).
434
435 (b) super(C, C()).__class__ would return C rather than super. This
436 is confusing. To fix this, I decided to change the semantics of
437 super so that it only applies to code attributes, not to data
438 attributes. After all, overriding data attributes is not
439 supported anyway.
440
441 (c) The __get__ method didn't check whether the argument was an
442 instance of the type used in creation of the super instance.
443
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000444- Previously, hash() of an instance of a subclass of a mutable type
445 (list or dictionary) would return some value, rather than raising
446 TypeError. This has been fixed. Also, directly calling
447 dict.__hash__ and list.__hash__ now raises the same TypeError
448 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000449
Guido van Rossumd331cb52001-12-05 19:46:42 +0000450- New-style objects now support deleting their __dict__. This is for
451 all intents and purposes equivalent to assigning a brand new empty
452 dictionary, but saves space if the object is not used further.
453
Tim Petersb3c9af12001-11-17 00:21:57 +0000454Core and builtins
455
Tim Peters3caca232001-12-06 06:23:26 +0000456- -Qnew now works as documented in PEP 238: when -Qnew is passed on
457 the command line, all occurrences of "/" use true division instead
458 of classic division. See the PEP for details. Note that "all"
459 means all instances in library and 3rd-party modules, as well as in
460 your own code. As the PEP says, -Qnew is intended for use only in
461 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000462 Note that test_coercion.py in the standard Python test suite fails
463 under -Qnew; this is expected, and won't be repaired until true
464 division becomes the default (in the meantime, test_coercion is
465 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000466
Fred Drake6c01e252001-12-14 17:08:12 +0000467- complex() now only allows the first argument to be a string
468 argument, and raises TypeError if either the second arg is a string
469 or if the second arg is specified when the first is a string.
470
Tim Petersb3c9af12001-11-17 00:21:57 +0000471Extension modules
472
Martin v. Löwis560da622001-11-24 09:24:51 +0000473- gc.get_referents was renamed to gc.get_referrers.
474
Tim Petersb3c9af12001-11-17 00:21:57 +0000475Library
476
Tim Peters25059d32001-12-07 20:35:43 +0000477- Functions in the os.spawn() family now release the global interpreter
478 lock around calling the platform spawn. They should always have done
479 this, but did not before 2.2c1. Multithreaded programs calling
480 an os.spawn function with P_WAIT will no longer block all Python threads
481 until the spawned program completes. It's possible that some programs
482 relies on blocking, although more likely by accident than by design.
483
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000484- webbrowser defaults to netscape.exe on OS/2 now.
485
Martin v. Löwis652e1912001-11-25 14:50:56 +0000486- Tix.ResizeHandle exposes detach_widget, hide, and show.
487
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000488- The charset alias windows_1252 has been added.
489
Barry Warsaw06557452001-12-14 20:47:12 +0000490- types.StringTypes is a tuple containing the defined string types;
491 usually this will be (str, unicode), but if Python was compiled
492 without Unicode support it will be just (str,).
493
494- The pulldom and minidom modules were synchronized to PyXML.
495
Tim Petersb3c9af12001-11-17 00:21:57 +0000496Tools/Demos
497
Barry Warsaw06557452001-12-14 20:47:12 +0000498- A new script called Tools/scripts/google.py was added, which fires
499 off a search on Google.
500
Tim Petersb3c9af12001-11-17 00:21:57 +0000501Build
502
Barry Warsaw06557452001-12-14 20:47:12 +0000503- Note that release builds of Python should arrange to define the
504 preprocessor symbol NDEBUG on the command line (or equivalent).
505 In the 2.2 pre-release series we tried to define this by magic in
506 Python.h instead, but it proved to cause problems for extension
507 authors. The Unix, Windows and Mac builds now all define NDEBUG in
508 release builds via cmdline (or equivalent) instead. Ports to
509 other platforms should do likewise.
510
Jack Jansen1999ef42001-12-06 21:47:20 +0000511- It is no longer necessary to use --with-suffix when building on a
512 case-insensitive file system (such as Mac OS X HFS+). In the build
513 directory an extension is used, but not in the installed python.
514
Tim Petersb3c9af12001-11-17 00:21:57 +0000515C API
516
Tim Petersf582b822001-12-11 18:51:08 +0000517- New function PyDict_MergeFromSeq2() exposes the builtin dict
518 constructor's logic for updating a dictionary from an iterable object
519 producing key-value pairs.
520
Tim Peterscffed4b2001-11-29 03:26:37 +0000521- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000522 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000523 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
524 dump core in some bad cases. This has been repaired. As a result,
525 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
526 previously went unchallenged.
527
Tim Petersb3c9af12001-11-17 00:21:57 +0000528New platforms
529
530Tests
531
532Windows
533
534Mac
535
Jack Jansenffa260f2001-12-06 21:14:00 +0000536- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
537 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000538
Barry Warsaw06557452001-12-14 20:47:12 +0000539- Changed logic for finding python home in Mac OS X framework Pythons.
540 Now sys.executable points to the executable again, in stead of to
541 the shared library. The latter is used only for locating the python
542 home.
543
544
Tim Peters84362bc2001-10-19 17:55:30 +0000545What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000546Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000547===========================
548
549Type/class unification and new-style classes
550
Guido van Rossum3d27df02001-11-15 20:27:54 +0000551- Multiple inheritance mixing new-style and classic classes in the
552 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000553
554 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000555 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000556
557 The MRO (method resolution order) for each base class is respected
558 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000559 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000560 This needs to be documented.
561
Tim Petersa427a2b2001-10-29 22:25:45 +0000562- The new builtin dictionary() constructor, and dictionary type, have
563 been renamed to dict. This reflects a decade of common usage.
564
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000565- dict() now accepts an iterable object producing 2-sequences. For
566 example, dict(d.items()) == d for any dictionary d. The argument,
567 and the elements of the argument, can be any iterable objects.
568
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000569- New-style classes can now have a __del__ method, which is called
570 when the instance is deleted (just like for classic classes).
571
Guido van Rossum12d955c2001-10-26 14:56:06 +0000572- Assignment to object.__dict__ is now possible, for objects that are
573 instances of new-style classes that have a __dict__ (unless the base
574 class forbids it).
575
Guido van Rossumc8e56452001-10-22 00:43:43 +0000576- Methods of built-in types now properly check for keyword arguments
577 (formerly these were silently ignored). The only built-in methods
578 that take keyword arguments are __call__, __init__ and __new__.
579
Guido van Rossum86443212001-10-27 22:28:54 +0000580- The socket function has been converted to a type; see below.
581
Tim Peters84362bc2001-10-19 17:55:30 +0000582Core and builtins
583
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000584- Assignment to __debug__ raises SyntaxError at compile-time. This
585 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000586 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000587
Guido van Rossum12d955c2001-10-26 14:56:06 +0000588- Clarified the error messages for unsupported operands to an operator
589 (like 1 + '').
590
Tim Peters84362bc2001-10-19 17:55:30 +0000591Extension modules
592
Tim Peters5ebfd362001-11-13 23:11:19 +0000593- mmap has a new keyword argument, "access", allowing a uniform way for
594 both Windows and Unix users to create read-only, write-through and
595 copy-on-write memory mappings. This was previously possible only on
596 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000597 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000598 platforms. Thanks to Jay T Miller for repairing this!
599
Tim Peters169ded02001-11-03 19:57:21 +0000600- By default, the gc.garbage list now contains only those instances in
601 unreachable cycles that have __del__ methods; in 2.1 it contained all
602 instances in unreachable cycles. "Instances" here has been generalized
603 to include instances of both new-style and old-style classes.
604
Guido van Rossum12d955c2001-10-26 14:56:06 +0000605- The socket module defines a new method for socket objects,
606 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000607 send() until all data has been sent. Also, the socket function has
608 been converted to a subclassable type, like list and tuple (etc.)
609 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000610
611- Various bugfixes to the curses module. There is now a test suite
612 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000613
Guido van Rossum692adf12001-10-30 03:03:03 +0000614- binascii.b2a_base64 no longer places an arbitrary restriction of 57
615 bytes on its input.
616
Tim Peters84362bc2001-10-19 17:55:30 +0000617Library
618
Tim Peters5ebfd362001-11-13 23:11:19 +0000619- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000620 convenience function.
621
Tim Peters75335872001-11-03 19:35:43 +0000622- Symbolic group names in regular expressions must be unique. For
623 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
624 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000625 Python 2.2 detects this error at regexp compilation time;
626 previously, the error went undetected, and results were
627 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
628 pattern.subn() methods have been rewritten in C. Also, an
629 experimental function/method finditer() has been added, which works
630 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000631
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000632- Tix exposes more commands through the classes DirSelectBox,
633 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
634 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
635 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
636
Tim Peters98791af2001-10-23 01:59:54 +0000637- Traceback objects are now scanned by cyclic garbage collection, so
638 cycles created by casual use of sys.exc_info() no longer cause
639 permanent memory leaks (provided garbage collection is enabled).
640
Guido van Rossum49192142001-10-24 20:51:44 +0000641- os.extsep -- a new variable needed by the RISCOS support. It is the
642 separator used by extensions, and is '.' on all platforms except
643 RISCOS, where it is '/'. There is no need to use this variable
644 unless you have a masochistic desire to port your code to RISCOS.
645
Barry Warsaw012852b2001-11-16 16:17:27 +0000646- mimetypes.py has optional support for non-standard, but commonly
647 found types. guess_type() and guess_extension() now accept an
648 optional `strict' flag, defaulting to true, which controls whether
649 recognize non-standard types or not. A few non-standard types we
650 know about have been added. Also, when run as a script, there are
651 new -l and -e options.
652
653- statcache is now deprecated.
654
655- email.Utils.formatdate() now produces the preferred RFC 2822 style
656 dates with numeric timezones (it used to produce obsolete dates
657 hard coded to "GMT" timezone). An optional `localtime' flag is
658 added to produce dates in the local timezone, with daylight savings
659 time properly taken into account.
660
661- In pickle and cPickle, instead of masking errors in load() by
662 transforming them into SystemError, we let the original exception
663 propagate out. Also, implement support for __safe_for_unpickling__
664 in pickle, as it already was supported in cPickle.
665
Tim Peters84362bc2001-10-19 17:55:30 +0000666Tools/Demos
667
668Build
669
Barry Warsaw012852b2001-11-16 16:17:27 +0000670- The dbm module is built using libdb1 if available. The bsddb module
671 is built with libdb3 if available.
672
673- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
674
Tim Peters84362bc2001-10-19 17:55:30 +0000675C API
676
Tim Peters1fc240e2001-10-26 05:06:50 +0000677- New function PySequence_Fast_GET_SIZE() returns the size of a non-
678 NULL result from PySequence_Fast(), more quickly than calling
679 PySequence_Size().
680
Barry Warsaw012852b2001-11-16 16:17:27 +0000681- New argument unpacking function PyArg_UnpackTuple() added.
682
683- New functions PyObject_CallFunctionObjArgs() and
684 PyObject_CallMethodObjArgs() have been added to make it more
685 convenient and efficient to call functions and methods from C.
686
687- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
688 possible that this will propagate errors it didn't before.
689
690- New function PyObject_CheckReadBuffer(), which returns true if its
691 argument supports the single-segment readable buffer interface.
692
Tim Peters84362bc2001-10-19 17:55:30 +0000693New platforms
694
Guido van Rossum86443212001-10-27 22:28:54 +0000695- We've finally confirmed that this release builds on HP-UX 11.00,
696 *with* threads, and passes the test suite.
697
Tim Peters7a33d8b2001-11-05 02:51:07 +0000698- Thanks to a series of patches from Michael Muller, Python may build
699 again under OS/2 Visual Age C++.
700
Guido van Rossum49192142001-10-24 20:51:44 +0000701- Updated RISCOS port by Dietmar Schwertberger.
702
Tim Peters84362bc2001-10-19 17:55:30 +0000703Tests
704
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000705- Added a test script for the curses module. It isn't run automatically;
706 regrtest.py must be run with '-u curses' to enable it.
707
Tim Peters84362bc2001-10-19 17:55:30 +0000708Windows
709
Barry Warsaw012852b2001-11-16 16:17:27 +0000710Mac
711
712- PythonScript has been moved to unsupported and is slated to be
713 removed completely in the next release.
714
715- It should now be possible to build applets that work on both OS9 and
716 OSX.
717
718- The core is now linked with CoreServices not Carbon; as a side
719 result, default 8bit encoding on OSX is now ASCII.
720
721- Python should now build on OSX 10.1.1
722
Tim Peters84362bc2001-10-19 17:55:30 +0000723
Tim Petersabf925f2001-09-28 21:53:42 +0000724What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000725Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000726===========================
727
728Type/class unification and new-style classes
729
Guido van Rossum687ae002001-10-15 22:03:32 +0000730- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000731 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000732 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000733 remains: the __dict__ of a new-style class is a read-only proxy; you
734 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000735 __defined__ attribute of new-style types no longer exists, for lack
736 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000737 future a __cache__ may be resurrected with a similar function, if I
738 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000739
Tim Peters1c9ca872001-10-04 06:43:12 +0000740- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
741 always returned None, even when there was a class docstring).
742
743- doctest now finds and runs docstrings attached to new-style classes,
744 class methods, static methods, and properties.
745
Guido van Rossum9074ef62001-10-16 21:34:49 +0000746Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000747
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000748- A very subtle syntactical pitfall in list comprehensions was fixed.
749 For example: [a+b for a in 'abc', for b in 'def']. The comma in
750 this example is a mistake. Previously, this would silently let 'a'
751 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
752 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
753 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
754 Note that [a for a in <singleton>] is a convoluted way to say
755 [<singleton>] anyway, so it's not like any expressiveness is lost.
756
Guido van Rossum9074ef62001-10-16 21:34:49 +0000757- getattr(obj, name, default) now only catches AttributeError, as
758 documented, rather than returning the default value for all
759 exceptions (which could mask bugs in a __getattr__ hook, for
760 example).
761
Fred Drakecb7a6b52001-10-22 18:41:51 +0000762- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000763 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000764 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000765 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000766
Guido van Rossum1c486092001-10-19 02:05:35 +0000767- unicode(obj) now behaves more like str(obj), accepting arbitrary
768 objects, and calling a __unicode__ method if it exists.
769 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000770 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000771
Barry Warsawf6fb1712001-10-19 05:35:40 +0000772- isinstance() now allows any object as the first argument and a
773 class, a type or something with a __bases__ tuple attribute for the
774 second argument. The second argument may also be a tuple of a
775 class, type, or something with __bases__, in which case isinstance()
776 will return true if the first argument is an instance of any of the
777 things contained in the second argument tuple. E.g.
778
779 isinstance(x, (A, B))
780
781 returns true if x is an instance of A or B.
782
Guido van Rossum9074ef62001-10-16 21:34:49 +0000783Extension modules
784
785- thread.start_new_thread() now returns the thread ID (previously None).
786
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000787- binascii has now two quopri support functions, a2b_qp and b2a_qp.
788
Guido van Rossumc524d952001-10-19 01:31:59 +0000789- readline now supports setting the startup_hook and the
790 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000791
Guido van Rossumc524d952001-10-19 01:31:59 +0000792- os and posix supports chroot(), setgroups() and unsetenv() where
793 available. The stat(), fstat(), statvfs() and fstatvfs() functions
794 now return "pseudo-sequences" -- the various fields can now be
795 accessed as attributes (e.g. os.stat("/").st_mtime) but for
796 backwards compatibility they also behave as a fixed-length sequence.
797 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000798 attributes.
799
800- time: localtime(), gmtime() and strptime() now return a
801 pseudo-sequence similar to the os.stat() return value, with
802 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000803
Guido van Rossum9074ef62001-10-16 21:34:49 +0000804- Decompression objects in the zlib module now accept an optional
805 second parameter to decompress() that specifies the maximum amount
806 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000807
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000808- optional SSL support in the socket module now exports OpenSSL
809 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
810 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000811 automatically seed its PRNG. Also, the keyfile and certfile
812 arguments to socket.ssl() are now optional.
813
814- posixmodule (and by extension, the os module on POSIX platforms) now
815 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000816
Guido van Rossum9074ef62001-10-16 21:34:49 +0000817Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000818
Tim Peters7402f792001-10-02 03:53:41 +0000819- doctest now excludes functions and classes not defined by the module
820 being tested, thanks to Tim Hochberg.
821
Fred Drakecb7a6b52001-10-22 18:41:51 +0000822- HotShot, a new profiler implemented using a C-based callback, has
823 been added. This substantially reduces the overhead of profiling,
824 but it is still quite preliminary. Support modules and
825 documentation will be added in upcoming releases (before 2.2 final).
826
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000827- profile now produces correct output in situations where an exception
828 raised in Python is cleared by C code (e.g. hasattr()). This used
829 to cause wrong output, including spurious claims of recursive
830 functions and attribution of time spent to the wrong function.
831
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000832 The code and documentation for the derived OldProfile and HotProfile
833 profiling classes was removed. The code hasn't worked for years (if
834 you tried to use them, they raised exceptions). OldProfile
835 intended to reproduce the behavior of the profiler Python used more
836 than 7 years ago, and isn't interesting anymore. HotProfile intended
837 to provide a faster profiler (but producing less information), and
838 that's a worthy goal we intend to meet via a different approach (but
839 without losing information).
840
Tim Peterscce092d2001-10-09 05:31:56 +0000841- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000842 a much better system-specific calibration constant. The constant can
843 now be specified in an instance constructor, or as a Profile class or
844 instance variable, instead of by editing profile.py's source code.
845 Calibration must still be done manually (see the docs for the profile
846 module).
847
848 Note that Profile.calibrate() must be overriden by subclasses.
849 Improving the accuracy required exploiting detailed knowledge of
850 profiler internals; the earlier method abstracted away the details
851 and measured a simplified model instead, but consequently computed
852 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000853
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000854- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000855 which indicates whether output is intended for the header 'Q'
856 encoding.
857
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000858- The SocketServer.ThreadingMixIn class now closes the request after
859 finish_request() returns. (Not when it errors out though.)
860
Barry Warsawf6fb1712001-10-19 05:35:40 +0000861- The nntplib module's NNTP.body() method has grown a `file' argument
862 to allow saving the message body to a file.
863
864- The email package has added a class email.Parser.HeaderParser which
865 only parses headers and does not recurse into the message's body.
866 Also, the module/class MIMEAudio has been added for representing
867 audio data (contributed by Anthony Baxter).
868
869- ftplib should be able to handle files > 2GB.
870
871- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
872 ON, and OFF.
873
Fred Drakecb7a6b52001-10-22 18:41:51 +0000874- xml.dom.minidom NodeList objects now support the length attribute
875 and item() method as required by the DOM specifications.
876
Guido van Rossumed554f62001-10-02 23:15:37 +0000877Tools/Demos
878
879- Demo/dns was removed. It no longer serves any purpose; a package
880 derived from it is now maintained by Anthony Baxter, see
881 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000882
Barry Warsawf6fb1712001-10-19 05:35:40 +0000883- The freeze tool has been made more robust, and two new options have
884 been added: -X and -E.
885
Tim Petersabf925f2001-09-28 21:53:42 +0000886Build
887
Barry Warsawf6fb1712001-10-19 05:35:40 +0000888- configure will use CXX in LINKCC if CXX is used to build main() and
889 the system requires to link a C++ main using the C++ compiler.
890
Tim Petersabf925f2001-09-28 21:53:42 +0000891C API
892
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000893- The documentation for the tp_compare slot is updated to require that
894 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
895 not correct. This is not yet enforced but will be enforced in
896 Python 2.3; even later, we may use -2 to indicate errors and +2 for
897 "NotImplemented". Right now, -1 should be used for an error return.
898
Tim Petersd38b1c72001-09-30 05:09:37 +0000899- PyLong_AsLongLong() now accepts int (as well as long) arguments.
900 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
901 as long) arguments.
902
Guido van Rossum3c288632001-10-16 21:13:49 +0000903- PyThread_start_new_thread() now returns a long int giving the thread
904 ID, if one can be calculated; it returns -1 for error, 0 if no
905 thread ID is calculated (this is an incompatible change, but only
906 the thread module used this API). This code has only really been
907 tested on Linux and Windows; other platforms please beware (and
908 report any bugs or strange behavior).
909
Guido van Rossum1c486092001-10-19 02:05:35 +0000910- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
911 input.
912
Tim Petersabf925f2001-09-28 21:53:42 +0000913New platforms
914
915Tests
916
917Windows
918
Tim Peters04cf1d32001-10-09 22:39:40 +0000919- Installer: If you install IDLE, and don't disable file-extension
920 registration, a new "Edit with IDLE" context (right-click) menu entry
921 is created for .py and .pyw files.
922
Tim Peters1ce3cf72001-10-01 17:58:40 +0000923- The signal module now supports SIGBREAK on Windows, thanks to Steven
924 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
925 action remains to call Win32 ExitProcess(). This can be changed via
926 signal.signal(). For example:
927
928 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
929 # (SIGINT) behavior.
930 import signal
931 signal.signal(signal.SIGBREAK,
932 signal.default_int_handler)
933
934 try:
935 while 1:
936 pass
937 except KeyboardInterrupt:
938 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
939 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
940 # program without the possibility for any Python-level cleanup).
941 print "Clean exit"
942
Tim Petersabf925f2001-09-28 21:53:42 +0000943
Tim Petersb07352e2001-09-08 01:25:47 +0000944What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000945Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000946===========================
947
Guido van Rossum808eea72001-09-25 04:15:41 +0000948Type/class unification and new-style classes
949
950- pydoc and inspect are now aware of new-style classes;
951 e.g. help(list) at the interactive prompt now shows proper
952 documentation for all operations on list objects.
953
954- Applications using Jim Fulton's ExtensionClass module can now safely
955 be used with Python 2.2. In particular, Zope 2.4.1 now works with
956 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
957 examples also work again. It is hoped that Gtk and Boost also work
958 with 2.2a4 and beyond. (If you can confirm this, please write
959 webmaster@python.org; if there are still problems, please open a bug
960 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000961
Tim Peters66c1a522001-09-24 21:17:50 +0000962- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000963 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +0000964 in the constructed property object. fget, fset and fdel weren't
965 discoverable from Python in 2.2a3. __doc__ is new, and allows to
966 associate a docstring with a property.
967
Guido van Rossum808eea72001-09-25 04:15:41 +0000968- Comparison overloading is now more completely implemented. For
969 example, a str subclass instance can properly be compared to a str
970 instance, and it can properly overload comparison. Ditto for most
971 other built-in object types.
972
973- The repr() of new-style classes has changed; instead of <type
974 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
975 *except* for built-in types, which are still rendered as <type
976 'Foo'> (to avoid upsetting existing code that might parse or
977 otherwise rely on repr() of certain type objects).
978
979- The repr() of new-style objects is now always <Foo object at XXX>;
980 previously, it was sometimes <Foo instance at XXX>.
981
982- For new-style classes, what was previously called __getattr__ is now
983 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000984 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000985 one in classic classes is defined which is called only if regular
986 attribute access raises AttributeError; to catch *all* attribute
987 access, you can use __getattribute__ (for new-style classes). If
988 both are defined, __getattribute__ is called first, and if it raises
989 AttributeError, __getattr__ is called.
990
991- The __class__ attribute of new-style objects can be assigned to.
992 The new class must have the same C-level object layout as the old
993 class.
994
995- The builtin file type can be subclassed now. In the usual pattern,
996 "file" is the name of the builtin type, and file() is a new builtin
997 constructor, with the same signature as the builtin open() function.
998 file() is now the preferred way to open a file.
999
1000- Previously, __new__ would only see sequential arguments passed to
1001 the type in a constructor call; __init__ would see both sequential
1002 and keyword arguments. This made no sense whatsoever any more, so
1003 now both __new__ and __init__ see all arguments.
1004
1005- Previously, hash() applied to an instance of a subclass of str or
1006 unicode always returned 0. This has been repaired.
1007
1008- Previously, an operation on an instance of a subclass of an
1009 immutable type (int, long, float, complex, tuple, str, unicode),
1010 where the subtype didn't override the operation (and so the
1011 operation was handled by the builtin type), could return that
1012 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001013 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001014 with the same value as s.
1015
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001016- Provisional support for pickling new-style objects has been added.
1017
Guido van Rossum808eea72001-09-25 04:15:41 +00001018Core
1019
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001020- file.writelines() now accepts any iterable object producing strings.
1021
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001022- PyUnicode_FromEncodedObject() now works very much like
1023 PyObject_Str(obj) in that it tries to use __str__/tp_str
1024 on the object if the object is not a string or buffer. This
1025 makes unicode() behave like str() when applied to non-string/buffer
1026 objects.
1027
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001028- PyFile_WriteObject now passes Unicode objects to the file's write
1029 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001030 of a print statement must support Unicode objects, i.e. they must
1031 at least convert them into ASCII strings.
1032
Guido van Rossum624c8af2001-09-18 15:21:04 +00001033- Thread scheduling on Solaris should be improved; it is no longer
1034 necessary to insert a small sleep at the start of a thread in order
1035 to let other runnable threads be scheduled.
1036
Tim Petersb07352e2001-09-08 01:25:47 +00001037Library
1038
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001039- StringIO.StringIO instances and cStringIO.StringIO instances support
1040 read character buffer compatible objects for their .write() methods.
1041 These objects are converted to strings and then handled as such
1042 by the instances.
1043
Barry Warsaw2f600732001-09-24 04:28:10 +00001044- The "email" package has been added. This is basically a port of the
1045 mimelib package <http://sf.net/projects/mimelib> with API changes
1046 and some implementations updated to use iterators and generators.
1047
Tim Peters8a9c2842001-09-22 21:30:22 +00001048- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1049 restores the ability of Tools/scripts/ndiff.py to start producing output
1050 before the entire comparison is complete.
1051
Barry Warsaw58b072d2001-09-22 04:44:21 +00001052- StringIO.StringIO instances and cStringIO.StringIO instances support
1053 iteration just like file objects (i.e. their .readline() method is
1054 called for each iteration until it returns an empty string).
1055
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001056- The codecs module has grown four new helper APIs to access
1057 builtin codecs: getencoder(), getdecoder(), getreader(),
1058 getwriter().
1059
Guido van Rossum624c8af2001-09-18 15:21:04 +00001060- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1061 simplifies writing XML RPC servers.
1062
Barry Warsaw647d5e82001-09-28 17:01:02 +00001063- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001064 after interpretation of symbolic links. On non-Unix systems, this
1065 is an alias for os.path.abspath().
1066
Tim Peters16a77ad2001-09-08 04:00:12 +00001067- operator.indexOf() (PySequence_Index() in the C API) now works with any
1068 iterable object.
1069
Guido van Rossum624c8af2001-09-18 15:21:04 +00001070- smtplib now supports various authentication and security features of
1071 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001072
Guido van Rossum624c8af2001-09-18 15:21:04 +00001073- hmac: a new module implementing keyed hashing for message
1074 authentication.
1075
1076- mimetypes now recognizes more extensions and file types. At the
1077 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001078
Guido van Rossum624c8af2001-09-18 15:21:04 +00001079- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001080 Python 2.2 bytecode generation. It has also been promoted from a
1081 Tool to a standard library package. (Tools/compiler still exists as
1082 a sample driver.)
1083
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001084Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001085
Tim Petersb07352e2001-09-08 01:25:47 +00001086Build
1087
Guido van Rossum624c8af2001-09-18 15:21:04 +00001088- Large file support (LFS) is now automatic when the platform supports
1089 it; no more manual configuration tweaks are needed. On Linux, at
1090 least, it's possible to have a system whose C library supports large
1091 files but whose kernel doesn't; in this case, large file support is
1092 still enabled but doesn't do you any good unless you upgrade your
1093 kernel or share your Python executable with another system whose
1094 kernel has large file support.
1095
1096- The configure script now supplies plausible defaults in a
1097 cross-compilation environment. This doesn't mean that the supplied
1098 values are always correct, or that cross-compilation now works
1099 flawlessly -- but it's a first step (and it shuts up most of
1100 autoconf's warnings about AC_TRY_RUN).
1101
1102- The Unix build is now a bit less chatty, courtesy of the parser
1103 generator. The build is completely silent (except for errors) when
1104 using "make -s", thanks to a -q option to setup.py.
1105
Tim Petersb07352e2001-09-08 01:25:47 +00001106C API
1107
Guido van Rossum624c8af2001-09-18 15:21:04 +00001108- The "structmember" API now supports some new flag bits to deny read
1109 and/or write access to attributes in restricted execution mode.
1110
Tim Petersb07352e2001-09-08 01:25:47 +00001111New platforms
1112
Guido van Rossum624c8af2001-09-18 15:21:04 +00001113- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1114 (http://familiar.handhelds.org).
1115
Tim Petersb07352e2001-09-08 01:25:47 +00001116Tests
1117
Tim Peters8a9c2842001-09-22 21:30:22 +00001118- The "classic" standard tests, which work by comparing stdout to
1119 an expected-output file under Lib/test/output/, no longer stop at
1120 the first mismatch. Instead the test is run to completion, and a
1121 variant of ndiff-style comparison is used to report all differences.
1122 This is much easier to understand than the previous style of reporting.
1123
1124- The unittest-based standard tests now use regrtest's test_main()
1125 convention, instead of running as a side-effect of merely being
1126 imported. This allows these tests to be run in more natural and
1127 flexible ways as unittests, outside the regrtest framework.
1128
1129- regrtest.py is much better integrated with unittest and doctest now,
1130 especially in regard to reporting errors.
1131
Tim Petersb07352e2001-09-08 01:25:47 +00001132Windows
1133
Guido van Rossum624c8af2001-09-18 15:21:04 +00001134- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001135 that support it (NTFS under Windows 2000). See "What's New in
1136 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001137
Tim Petersb07352e2001-09-08 01:25:47 +00001138
Tim Petersedc99312001-08-22 21:36:50 +00001139What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001140Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001141===========================
1142
1143Core
1144
Tim Peters9fffa3e2001-09-04 05:14:19 +00001145- Conversion of long to float now raises OverflowError if the long is too
1146 big to represent as a C double.
1147
Tim Peters32f453e2001-09-03 08:35:41 +00001148- The 3-argument builtin pow() no longer allows a third non-None argument
1149 if either of the first two arguments is a float, or if both are of
1150 integer types and the second argument is negative (in which latter case
1151 the arguments are converted to float, so this is really the same
1152 restriction).
1153
Tim Peters5d2b77c2001-09-03 05:47:38 +00001154- The builtin dir() now returns more information, and sometimes much
1155 more, generally naming all attributes of an object, and all attributes
1156 reachable from the object via its class, and from its class's base
1157 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1158 an empty list. In 2.2a3,
1159
1160 >>> dir([])
1161 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1162 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1163 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1164 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1165 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1166 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1167 'reverse', 'sort']
1168
1169 dir(module) continues to return only the module's attributes, though.
1170
Tim Petersbdee63f2001-09-02 03:40:59 +00001171- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001172 than raising OverflowError. This is a partial implementation of PEP
1173 237. You can use -Wdefault::OverflowWarning to enable a warning for
1174 this situation, and -Werror::OverflowWarning to revert to the old
1175 OverflowError exception.
1176
Guido van Rossum61c345f2001-09-04 03:26:15 +00001177- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001178 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001179 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1180 -Qold, meaning the / operator has its classic meaning and no
1181 warnings are issued. Using -Qwarn issues a run-time warning about
1182 all uses of classic division for int and long arguments; -Qwarnall
1183 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001184 (for use with fixdiv.py).
1185 [Note: the remainder of this paragraph (preserved below) became
1186 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1187 <obsolete>
1188 Using -Qnew is questionable; it turns on new division by default, but
1189 only in the __main__ module. You can usefully combine -Qwarn or
1190 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1191 warns about classic division everywhere else.
1192 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001193
Tim Petersbdee63f2001-09-02 03:40:59 +00001194- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001195 long, float, str, unicode, and tuple. (The types complex, list and
1196 dictionary can also be subclassed; this was introduced earlier.)
1197 Note that restrictions apply when subclassing immutable built-in
1198 types: you can only affect the value of the instance by overloading
1199 __new__. You can add mutable attributes, and the subclass instances
1200 will have a __dict__ attribute, but you cannot change the "value"
1201 (as implemented by the base class) of an immutable subclass instance
1202 once it is created.
1203
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001204- The dictionary constructor now takes an optional argument, a
1205 mapping-like object, and initializes the dictionary from its
1206 (key, value) pairs.
1207
Tim Petersbdee63f2001-09-02 03:40:59 +00001208- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001209 "cooperative super calls" in a multiple inheritance setting. For an
1210 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1211
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001212- A new built-in type, property, has been added. This enables the
1213 creation of "properties". These are attributes implemented by
1214 getter and setter functions (or only one of these for read-only or
1215 write-only attributes), without the need to override __getattr__.
1216 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001217
Tim Petersbdee63f2001-09-02 03:40:59 +00001218- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001219 liberalized, to allow leading zeroes. Examples of literals now
1220 legal that were SyntaxErrors before:
1221
1222 00.0 0e3 0100j 07.5 00000000000000000008.
1223
Tim Petersbdee63f2001-09-02 03:40:59 +00001224- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001225 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1226
Tim Petersedc99312001-08-22 21:36:50 +00001227Library
1228
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001229- telnetlib includes symbolic names for the options, and support for
1230 setting an option negotiation callback.
1231
Tim Petersa40c7932001-09-05 22:36:56 +00001232- The new C standard no longer requires that math libraries set errno to
1233 ERANGE on overflow. For platform libraries that exploit this new
1234 freedom, Python's overflow-checking was wholly broken. A new overflow-
1235 checking scheme attempts to repair that, but may not be reliable on all
1236 platforms (C doesn't seem to provide anything both useful and portable
1237 in this area anymore).
1238
Martin v. Löwis44f86962001-09-05 13:44:54 +00001239- Asynchronous timeout actions are available through the new class
1240 threading.Timer.
1241
Tim Peters78526162001-09-05 00:53:45 +00001242- math.log and math.log10 now return sensible results for even huge
1243 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1244
Tim Petersbdee63f2001-09-02 03:40:59 +00001245- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001246 currently held. See the docs for the imp module.
1247
Tim Petersbdee63f2001-09-02 03:40:59 +00001248- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001249 dumps containing ints written on platforms where Python ints are 8 bytes.
1250 When read on a box where Python ints are 4 bytes, such values are
1251 converted to Python longs.
1252
Tim Petersbdee63f2001-09-02 03:40:59 +00001253- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001254 code objects is no longer allowed. This plugs a security hole.
1255
Steve Purcell6091cd62001-09-06 16:05:17 +00001256- unittest.TestResult instances no longer store references to tracebacks
1257 generated by test failures. This prevents unexpected dangling references
1258 to objects that should be garbage collected between tests.
1259
Tim Petersedc99312001-08-22 21:36:50 +00001260Tools
1261
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001262- Tools/scripts/fixdiv.py has been added which can be used to fix
1263 division operators as per PEP 238.
1264
Tim Petersedc99312001-08-22 21:36:50 +00001265Build
1266
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001267- If you are an adventurous person using Mac OS X you may want to look at
1268 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1269 application, which can be used for experimenting with Carbon or Cocoa.
1270 Discussion of this on pythonmac-sig, please.
1271
Tim Peters7eea37e2001-09-04 22:08:56 +00001272C API
1273
1274- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001275
Tim Peters9fffa3e2001-09-04 05:14:19 +00001276- Note that PyLong_AsDouble can fail! This has always been true, but no
1277 callers checked for it. It's more likely to fail now, because overflow
1278 errors are properly detected now. The proper way to check:
1279
1280 double x = PyLong_AsDouble(some_long_object);
1281 if (x == -1.0 && PyErr_Occurred()) {
1282 /* The conversion failed. */
1283 }
1284
Tim Petersbdee63f2001-09-02 03:40:59 +00001285- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001286 compile but will not participate in GC. To upgrade an extension
1287 module:
1288
1289 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001290
Neil Schemenauer4042c692001-08-30 15:38:01 +00001291 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1292 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001293
Neil Schemenauer4042c692001-08-30 15:38:01 +00001294 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1295 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001296
Neil Schemenauer4042c692001-08-30 15:38:01 +00001297 - remove PyGC_HEAD_SIZE from object size calculations
1298
1299 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1300
Tim Petersbdee63f2001-09-02 03:40:59 +00001301- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001302 These can be used safely to construct string objects from a
1303 sprintf-style format string (similar to the format string supported
1304 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001305
Tim Petersedc99312001-08-22 21:36:50 +00001306New platforms
1307
Tim Petersb7da0902001-09-02 23:01:43 +00001308- Stephen Hansen contributed patches sufficient to get a clean compile
1309 under Borland C (Windows), but he reports problems running it and ran
1310 out of time to complete the port. Volunteers? Expect a MemoryError
1311 when importing the types module; this is probably shallow, and
1312 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001313
Tim Petersedc99312001-08-22 21:36:50 +00001314Tests
1315
1316Windows
1317
Tim Peters6e13a562001-09-06 00:32:15 +00001318- Large file support is now enabled on Win32 platforms as well as on
1319 Win64. This means that, for example, you can use f.tell() and f.seek()
1320 to manipulate files larger than 2 gigabytes (provided you have enough
1321 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001322 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1323 filesize limit, and large file support makes no difference there.
1324 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1325 NTFS has no practical limit on file size, and files of any size can be
1326 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001327
Tim Petersbdee63f2001-09-02 03:40:59 +00001328- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001329 points to command.com (patch from Brian Quinlan).
1330
Tim Petersedc99312001-08-22 21:36:50 +00001331
Tim Peters20f51a72001-07-21 02:31:40 +00001332What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001333Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001334===========================
1335
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001336Build
1337
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001338- Tim Peters developed a brand new Windows installer using Wise 8.1,
1339 generously donated to us by Wise Solutions.
1340
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001341- configure supports a new option --enable-unicode, with the values
1342 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1343 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001344
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001345- A new configure option --enable-framework builds a Mac OS X framework,
1346 which "make frameworkinstall" will install. This provides a starting
1347 point for more mac-like functionality, join pythonmac-sig@python.org
1348 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001349
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001350- The NeXT platform is no longer supported.
1351
1352- The `new' module is now statically linked.
1353
Tim Peters0afb6092001-08-15 06:06:44 +00001354Tools
1355
1356- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001357 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001358 the module docstring for details.
1359
Tim Peters20f51a72001-07-21 02:31:40 +00001360Tests
1361
Tim Peters5e824c32001-08-12 22:25:01 +00001362- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001363 platforms, allowing to give clearer test result output. regrtest
1364 also has optional --use/-u switch to run normally disabled tests
1365 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001366
Tim Peters20f51a72001-07-21 02:31:40 +00001367- Several new tests in the standard test suite, with special thanks to
1368 Nick Mathewson.
1369
1370Core
1371
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001372- The floor division operator // has been added as outlined in PEP
1373 238. The / operator still provides classic division (and will until
1374 Python 3.0) unless "from __future__ import division" is included, in
1375 which case the / operator will provide true division. The operator
1376 module provides truediv() and floordiv() functions. Augmented
1377 assignment variants are included, as are the equivalent overloadable
1378 methods and C API methods. See the PEP for a full discussion:
1379 <http://python.sf.net/peps/pep-0238.html>
1380
Tim Peters6cd6a822001-08-17 22:11:27 +00001381- Future statements are now effective in simulated interactive shells
1382 (like IDLE). This should "just work" by magic, but read Michael
1383 Hudson's "Future statements in simulated shells" PEP 264 for full
1384 details: <http://python.sf.net/peps/pep-0264.html>.
1385
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001386- The type/class unification (PEP 252-253) was integrated into the
1387 trunk and is not so tentative any more (the exact specification of
1388 some features is still tentative). A lot of work has done on fixing
1389 bugs and adding robustness and features (performance still has to
1390 come a long way).
1391
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001392- Warnings about a mismatch in the Python API during extension import
1393 now use the Python warning framework (which makes it possible to
1394 write filters for these warnings).
1395
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001396- A function's __dict__ (aka func_dict) will now always be a
1397 dictionary. It used to be possible to delete it or set it to None,
1398 but now both actions raise TypeErrors. It is still legal to set it
1399 to a dictionary object. Getting func.__dict__ before any attributes
1400 have been assigned now returns an empty dictionary instead of None.
1401
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001402- A new command line option, -E, was added which disables the use of
1403 all environment variables, or at least those that are specifically
1404 significant to Python. Usually those have a name starting with
1405 "PYTHON". This was used to fix a problem where the tests fail if
1406 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1407 older distribution.
1408
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001409Library
1410
Tim Peters5e824c32001-08-12 22:25:01 +00001411- New class Differ and new functions ndiff() and restore() in difflib.py.
1412 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001413 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001414
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001415- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1416 value using the minimal quoting required for the value; more
1417 reliable than using xml.sax.saxutils.escape() for attribute values.
1418
1419- Readline completion support for cmd.Cmd was added.
1420
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001421- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1422
1423- Added function threading.BoundedSemaphore()
1424
1425- Added Ka-Ping Yee's cgitb.py module.
1426
1427- The `new' module now exposes the CO_xxx flags.
1428
Martin v. Löwis560da622001-11-24 09:24:51 +00001429- The gc module offers the get_referents function.
1430
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001431New platforms
1432
1433C API
1434
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001435- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1436 which provide a cross-platform implementations for the
1437 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1438 the standard sprintf() and vsprintf() C lib APIs, these versions
1439 apply bounds checking on the used buffer which enhances protection
1440 against buffer overruns.
1441
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001442- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001443 and extensions using different Unicode widths is rendered next to
1444 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001445 will result in an ImportError. Unicode extensions writers must make
1446 sure to check the Unicode width compatibility in their extensions by
1447 using at least one of the mangled Unicode APIs in the extension.
1448
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001449- Two new flags METH_NOARGS and METH_O are available in method definition
1450 tables to simplify implementation of methods with no arguments and a
1451 single untyped argument. Calling such methods is more efficient than
1452 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1453 deprecated.
1454
Tim Petersc1731372001-08-04 08:12:36 +00001455Windows
1456
1457- "import module" now compiles module.pyw if it exists and nothing else
1458 relevant is found.
1459
Tim Peters20f51a72001-07-21 02:31:40 +00001460
Guido van Rossum55a78992001-07-17 17:22:32 +00001461What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001462Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001463===========================
1464
1465Core
Tim Petersa814db52001-05-14 07:05:58 +00001466
Tim Peters6d6c1a32001-08-02 04:15:00 +00001467- TENTATIVELY, a large amount of code implementing much of what's
1468 described in PEP 252 (Making Types Look More Like Classes) and PEP
1469 253 (Subtyping Built-in Types) was added. This will be released
1470 with Python 2.2a1. Documentation will be provided separately
1471 through http://www.python.org/2.2/. The purpose of releasing this
1472 with Python 2.2a1 is to test backwards compatibility. It is
1473 possible, though not likely, that a decision is made not to release
1474 this code as part of 2.2 final, if any serious backwards
1475 incompapatibilities are found during alpha testing that cannot be
1476 repaired.
1477
Guido van Rossum55a78992001-07-17 17:22:32 +00001478- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001479 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001480 more 'yield' statements. See PEP 255. Since this adds a new
1481 keyword to the language, this feature must be enabled by including a
1482 future statement: "from __future__ import generators" (see PEP 236).
1483 Generators will become a standard feature in a future release
1484 (probably 2.3). Without this future statement, 'yield' remains an
1485 ordinary identifier, but a warning is issued each time it is used.
1486 (These warnings currently don't conform to the warnings framework of
1487 PEP 230; we intend to fix this in 2.2a2.)
1488
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001489- The UTF-16 codec was modified to be more RFC compliant. It will now
1490 only remove BOM characters at the start of the string and then
1491 only if running in native mode (UTF-16-LE and -BE won't remove a
1492 leading BMO character).
1493
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001494- Strings now have a new method .decode() to complement the already
1495 existing .encode() method. These two methods provide direct access
1496 to the corresponding decoders and encoders of the registered codecs.
1497
1498 To enhance the usability of the .encode() method, the special
1499 casing of Unicode object return values was dropped (Unicode objects
1500 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001501
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001502 Both methods will now return whatever the codec in charge of the
1503 requested encoding returns as object, e.g. Unicode codecs will
1504 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1505 will return u"äöü"). This enables codec writer to create codecs
1506 for various simple to use conversions.
1507
1508 New codecs were added to demonstrate these new features (the .encode()
1509 and .decode() columns indicate the type of the returned objects):
1510
1511 Name | .encode() | .decode() | Description
1512 ----------------------------------------------------------------------
1513 uu | string | string | UU codec (e.g. for email)
1514 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001515 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001516 zlib | string | string | zlib compression
1517 hex | string | string | 2-byte hex codec
1518 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1519
Mark Hammond2a0af792001-05-14 03:09:36 +00001520- Some operating systems now support the concept of a default Unicode
1521 encoding for file system operations. Notably, Windows supports 'mbcs'
1522 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001523 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001524 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001525
1526 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001527 functions that return filenames (such as os.listdir()) to return Python
1528 string objects pre-encoded using the default file system encoding for
1529 the platform. As this encoding is likely to be different from Python's
1530 default encoding, converting this name to a Unicode object before passing
1531 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001532 would attempt to use its default encoding (generally ASCII) rather than
1533 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001534
Tim Petersa814db52001-05-14 07:05:58 +00001535 In general, this change simply removes surprises when working with
1536 Unicode and the file system, making these operations work as you expect,
1537 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001538 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001539
Tim Peters61dff2b2001-05-08 15:43:37 +00001540- Float (and complex) literals in source code were evaluated to full
1541 precision only when running from a .py file; the same code loaded from a
1542 .pyc (or .pyo) file could suffer numeric differences starting at about the
1543 12th significant decimal digit. For example, on a machine with IEEE-754
1544 floating arithmetic,
1545
1546 x = 9007199254740992.0
1547 print long(x)
1548
1549 printed 9007199254740992 if run directly from .py, but 9007199254740000
1550 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1551 str(float) instead of repr(float) when building code objects. marshal
1552 now uses repr(float) instead, which should reproduce floats to full
1553 machine precision (assuming the platform C float<->string I/O conversion
1554 functions are of good quality).
1555
1556 This may cause floating-point results to change in some cases, and
1557 usually for the better, but may also cause numerically unstable
1558 algorithms to break.
1559
Tim Peters2f228e72001-05-13 00:19:31 +00001560- The implementation of dicts suffers fewer collisions, which has speed
1561 benefits. However, the order in which dict entries appear in dict.keys(),
1562 dict.values() and dict.items() may differ from previous releases for a
1563 given dict. Nothing is defined about this order, so no program should
1564 rely on it. Nevertheless, it's easy to write test cases that rely on the
1565 order by accident, typically because of printing the str() or repr() of a
1566 dict to an "expected results" file. See Lib/test/test_support.py's new
1567 sortdict(dict) function for a simple way to display a dict in sorted
1568 order.
1569
Tim Peters7a3bfc32001-06-12 01:22:22 +00001570- Many other small changes to dicts were made, resulting in faster
1571 operation along the most common code paths.
1572
Guido van Rossum10315822001-05-01 20:54:30 +00001573- Dictionary objects now support the "in" operator: "x in dict" means
1574 the same as dict.has_key(x).
1575
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001576- The update() method of dictionaries now accepts generic mapping
1577 objects. Specifically the argument object must support the .keys()
1578 and __getitem__() methods. This allows you to say, for example,
1579 {}.update(UserDict())
1580
Guido van Rossum10315822001-05-01 20:54:30 +00001581- Iterators were added; this is a generalized way of providing values
1582 to a for loop. See PEP 234. There's a new built-in function iter()
1583 to return an iterator. There's a new protocol to get the next value
1584 from an iterator using the next() method (in Python) or the
1585 tp_iternext slot (in C). There's a new protocol to get iterators
1586 using the __iter__() method (in Python) or the tp_iter slot (in C).
1587 Iterating (i.e. a for loop) over a dictionary generates its keys.
1588 Iterating over a file generates its lines.
1589
Tim Petersf553f892001-05-01 20:45:31 +00001590- The following functions were generalized to work nicely with iterator
1591 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001592 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001593 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1594 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001595 join() method of strings
1596 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001597 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1598 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001599 right-hand side of assignment statements with multiple targets, such as
1600 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001601
Tim Petersd85e1022001-05-11 21:51:48 +00001602- Accessing module attributes is significantly faster (for example,
1603 random.random or os.path or yourPythonModule.yourAttribute).
1604
Tim Peterse63415e2001-05-08 04:38:29 +00001605- Comparing dictionary objects via == and != is faster, and now works even
1606 if the keys and values don't support comparisons other than ==.
1607
Tim Peters95bf9392001-05-10 08:32:44 +00001608- Comparing dictionaries in ways other than == and != is slower: there were
1609 insecurities in the dict comparison implementation that could cause Python
1610 to crash if the element comparison routines for the dict keys and/or
1611 values mutated the dicts. Making the code bulletproof slowed it down.
1612
Tim Peterseb28ef22001-06-02 05:27:19 +00001613- Collisions in dicts are resolved via a new approach, which can help
1614 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001615 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001616 faster now. Thanks to Christian Tismer for pointing out the cause and
1617 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001618
Tim Peters52e155e2001-06-16 05:42:57 +00001619- repr() is much faster for large containers (dict, list, tuple).
1620
1621
Tim Petersa814db52001-05-14 07:05:58 +00001622Library
1623
Fred Drake960fdf92001-07-20 18:38:26 +00001624- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1625 were added to the string module. These a locale-indenpendent
1626 constants, unlike letters, lowercase, and uppercase. These are now
1627 use in appropriate locations in the standard library.
1628
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001629- The flags used in dlopen calls can now be configured using
1630 sys.setdlopenflags and queried using sys.getdlopenflags.
1631
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001632- Fredrik Lundh's xmlrpclib is now a standard library module. This
1633 provides full client-side XML-RPC support. In addition,
1634 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1635 one asyncore-based). Thanks to Eric Raymond for the documentation.
1636
Guido van Rossum643d3912001-07-05 14:46:25 +00001637- The xrange() object is simplified: it no longer supports slicing,
1638 repetition, comparisons, efficient 'in' checking, the tolist()
1639 method, or the start, stop and step attributes. See PEP 260.
1640
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001641- A new function fnmatch.filter to filter lists of file names was added.
1642
Barry Warsawffd674d2001-05-22 16:00:10 +00001643- calendar.py uses month and day names based on the current locale.
1644
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001645- strop is now *really* obsolete (this was announced before with 1.6),
1646 and issues DeprecationWarning when used (except for the four items
1647 that are still imported into string.py).
1648
Tim Petersa814db52001-05-14 07:05:58 +00001649- Cookie.py now sorts key+value pairs by key in output strings.
1650
1651- pprint.isrecursive(object) didn't correctly identify recursive objects.
1652 Now it does.
1653
Tim Peters95b3f782001-05-14 18:39:41 +00001654- pprint functions now much faster for large containers (tuple, list, dict).
1655
Tim Peters7b9542a2001-06-10 23:40:19 +00001656- New 'q' and 'Q' format codes in the struct module, corresponding to C
1657 types "long long" and "unsigned long long" (on Windows, __int64). In
1658 native mode, these can be used only when the platform C compiler supports
1659 these types (when HAVE_LONG_LONG is #define'd by the Python config
1660 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001661 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1662 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001663
Guido van Rossum83213cc2001-06-12 16:48:52 +00001664- The site module installs a new built-in function 'help' that invokes
1665 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1666 it displays a message reminding the user to use 'help()' or
1667 'help(object)'.
1668
Tim Petersa814db52001-05-14 07:05:58 +00001669Tests
1670
1671- New test_mutants.py runs dict comparisons where the key and value
1672 comparison operators mutute the dicts randomly during comparison. This
1673 rapidly causes Python to crash under earlier releases (not for the faint
1674 of heart: it can also cause Win9x to freeze or reboot!).
1675
1676- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001677 pprint.isreadable() return sensible results. Also verifies that simple
1678 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001679
Tim Peters4324aa32001-05-28 22:30:08 +00001680C API
1681
1682- Removed the unused last_is_sticky argument from the internal
1683 _PyTuple_Resize(). If this affects you, you were cheating.
1684
1685
Guido van Rossum55a78992001-07-17 17:22:32 +00001686======================================================================
1687
1688
Guido van Rossumffe13be2001-04-16 18:46:45 +00001689What's New in Python 2.1 (final)?
1690=================================
1691
1692We only changed a few things since the last release candidate, all in
1693Python library code:
1694
1695- A bug in the locale module was fixed that affected locales which
1696 define no grouping for numeric formatting.
1697
1698- A few bugs in the weakref module's implementations of weak
1699 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1700 and the test suite was updated to check for these bugs.
1701
1702- An old bug in the os.path.walk() function (introduced in Python
1703 2.0!) was fixed: a non-existent file would cause an exception
1704 instead of being ignored.
1705
1706- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1707 PyChecker.
1708
1709
Guido van Rossum5b08f132001-04-16 02:05:23 +00001710What's New in Python 2.1c2?
1711===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001712
Guido van Rossum5b08f132001-04-16 02:05:23 +00001713A flurry of small changes, and one showstopper fixed in the nick of
1714time made it necessary to release another release candidate. The list
1715here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001716
Guido van Rossum5b08f132001-04-16 02:05:23 +00001717Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001718
Guido van Rossum5b08f132001-04-16 02:05:23 +00001719- Tim discovered a nasty bug in the dictionary code, caused by
1720 PyDict_Next() calling dict_resize(), and the GC code's use of
1721 PyDict_Next() violating an assumption in dict_items(). This was
1722 fixed with considerable amounts of band-aid, but the net effect is a
1723 saner and more robust implementation.
1724
1725- Made a bunch of symbols static that were accidentally global.
1726
1727Build and Ports
1728
1729- The setup.py script didn't check for a new enough version of zlib
1730 (1.1.3 is needed). Now it does.
1731
1732- Changed "make clean" target to also remove shared libraries.
1733
1734- Added a more general warning about the SGI Irix optimizer to README.
1735
1736Library
1737
1738- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1739 omitted the slash between host and file.html.
1740
1741- The mailbox module's _Mailbox class contained a completely broken
1742 and undocumented seek() method. Ripped it out.
1743
1744- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1745 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1746
1747- Fixed a few last-minute bugs in unittest.
1748
1749Extensions
1750
1751- Reverted the patch to the OpenSSL code in socketmodule.c to support
1752 RAND_status() and the EGD, and the subsequent patch that tried to
1753 fix it for pre-0.9.5 versions; the problem with the patch is that on
1754 some systems it issues a warning whenever socket is imported, and
1755 that's unacceptable.
1756
1757Tests
1758
1759- Fixed the pickle tests to work with "import test.test_pickle".
1760
1761- Tweaked test_locale.py to actually run the test Windows.
1762
1763- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1764 not "wb" (which is not a valid mode at all).
1765
1766- Fix pstats browser crashes. Import readline if it exists to make
1767 the user interface nicer.
1768
1769- Add "import thread" to the top of test modules that import the
1770 threading module (test_asynchat and test_threadedtempfile). This
1771 prevents test failures caused by a broken threading module resulting
1772 from a previously caught failed import.
1773
1774- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1775 needed on some platforms (e.g. Solaris 8) when the tests are run
1776 twice in succession.
1777
1778- Skip rather than fail test_sunaudiodev if no audio device is found.
1779
1780
1781What's New in Python 2.1c1?
1782===========================
1783
1784This list was significantly updated when 2.1c2 was released; the 2.1c1
1785release didn't mention most changes that were actually part of 2.1c1:
1786
1787Legal
1788
1789- Copyright was assigned to the Python Software Foundation (PSF) and a
1790 PSF license (very similar to the CNRI license) was added.
1791
1792- The CNRI copyright notice was updated to include 2001.
1793
1794Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001795
Guido van Rossumc9932722001-04-12 02:31:27 +00001796- After a public outcry, assignment to __debug__ is no longer illegal;
1797 instead, a warning is issued. It will become illegal in 2.2.
1798
Guido van Rossum5b08f132001-04-16 02:05:23 +00001799- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1800 "%#x" now always prepends "0x", even if the value is zero.
1801
1802- Fixed some nits in the bytecode compiler.
1803
1804- Fixed core dumps when calling certain kinds of non-functions.
1805
1806- Fixed various core dumps caused by reference count bugs.
1807
1808Build and Ports
1809
1810- Use INSTALL_SCRIPT to install script files.
1811
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001812- New port: SCO Unixware 7, by Billy G. Allie.
1813
Guido van Rossum5b08f132001-04-16 02:05:23 +00001814- Updated RISCOS port.
1815
1816- Updated BeOS port and notes.
1817
1818- Various other porting problems resolved.
1819
1820Library
1821
1822- The TERMIOS and SOCKET modules are now truly obsolete and
1823 unnecessary. Their symbols are incorporated in the termios and
1824 socket modules.
1825
1826- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1827 better tests for pickling.
1828
1829- threading: make Condition.wait() robust against KeyboardInterrupt.
1830
1831- zipfile: add support to zipfile to support opening an archive
1832 represented by an open file rather than a file name. Fix bug where
1833 the archive was not properly closed. Fixed a bug in this bugfix
1834 where flush() was called for a read-only file.
1835
1836- imputil: added an uninstall() method to the ImportManager.
1837
1838- Canvas: fixed bugs in lower() and tkraise() methods.
1839
1840- SocketServer: API change (added overridable close_request() method)
1841 so that the TCP server can explicitly close the request.
1842
1843- pstats: Eric Raymond added a simple interactive statistics browser,
1844 invoked when the module is run as a script.
1845
1846- locale: fixed a problem in format().
1847
1848- webbrowser: made it work when the BROWSER environment variable has a
1849 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1850 KDE 2. Fixed some other nits.
1851
1852- unittest: changes to allow using a different exception than
1853 AssertionError, and added a few more function aliases. Some other
1854 small changes.
1855
1856- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1857
1858- asynchat: fixed a critical bug in asynchat that slipped through the
1859 2.1b2 release. Fixed another rare bug.
1860
1861- Fix some unqualified except: clauses (always a bad code example).
1862
1863XML
1864
1865- pyexpat: new API get_version_string().
1866
1867- Fixed some minidom bugs.
1868
1869Extensions
1870
1871- Fixed a core dump in _weakref. Removed the weakref.mapping()
1872 function (it adds nothing to the API).
1873
1874- Rationalized the use of header files in the readline module, to make
1875 it compile (albeit with some warnings) with the very recent readline
1876 4.2, without breaking for earlier versions.
1877
1878- Hopefully fixed a buffering problem in linuxaudiodev.
1879
1880- Attempted a fix to make the OpenSSL support in the socket module
1881 work again with pre-0.9.5 versions of OpenSSL.
1882
1883Tests
1884
1885- Added a test case for asynchat and asyncore.
1886
1887- Removed coupling between tests where one test failing could break
1888 another.
1889
1890Tools
1891
1892- Ping added an interactive help browser to pydoc, fixed some nits
1893 in the rest of the pydoc code, and added some features to his
1894 inspect module.
1895
1896- An updated python-mode.el version 4.1 which integrates Ken
1897 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1898 much nicer in XEmacs and Emacs. When stepping through your program
1899 with pdb, in either the shell window or the *Python* window, the
1900 source file and line will be tracked by an arrow. Very cool!
1901
1902- IDLE: syntax warnings in interactive mode are changed into errors.
1903
1904- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001905 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001906
1907- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001908
Barry Warsaw11e89c72001-04-11 20:37:57 +00001909
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001910What's New in Python 2.1 beta 2?
1911================================
1912
Guido van Rossum053ae352001-03-22 14:17:21 +00001913(Unlisted are many fixed bugs, more documentation, etc.)
1914
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001915Core language, builtins, and interpreter
1916
Guido van Rossum053ae352001-03-22 14:17:21 +00001917- The nested scopes work (enabled by "from __future__ import
1918 nested_scopes") is completed; in particular, the future now extends
1919 into code executed through exec, eval() and execfile(), and into the
1920 interactive interpreter.
1921
1922- When calling a base class method (e.g. BaseClass.__init__(self)),
1923 this is now allowed even if self is not strictly spoken a class
1924 instance (e.g. when using metaclasses or the Don Beaudry hook).
1925
1926- Slice objects are now comparable but not hashable; this prevents
1927 dict[:] from being accepted but meaningless.
1928
1929- Complex division is now calculated using less braindead algorithms.
1930 This doesn't change semantics except it's more likely to give useful
1931 results in extreme cases. Complex repr() now uses full precision
1932 like float repr().
1933
1934- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1935
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001936- It is illegal to assign to the name __debug__, which is set when the
1937 interpreter starts. It is effectively a compile-time constant.
1938
1939- A warning will be issued if a global statement for a variable
1940 follows a use or assignment of that variable.
1941
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001942Standard library
1943
Guido van Rossum053ae352001-03-22 14:17:21 +00001944- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1945 inspired by JUnit), is now part of the standard library. You now
1946 have a choice of two testing frameworks: unittest requires you to
1947 write testcases as separate code, doctest gathers them from
1948 docstrings. Both approaches have their advantages and
1949 disadvantages.
1950
1951- A new module Tix was added, which wraps the Tix extension library
1952 for Tk. With that module, it is not necessary to statically link
1953 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1954 require" command. See Demo/tix/.
1955
1956- tzparse.py is now obsolete.
1957
1958- In gzip.py, the seek() and tell() methods are removed -- they were
1959 non-functional anyway, and it's better if callers can test for their
1960 existence with hasattr().
1961
1962Python/C API
1963
1964- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1965 that's already in the dictionary during a PyDict_Next() iteration.
1966 This used to fail occasionally when a dictionary resize operation
1967 could be triggered that would rehash all the keys. All other
1968 modifications to the dictionary are still off-limits during a
1969 PyDict_Next() iteration!
1970
1971- New extended APIs related to passing compiler variables around.
1972
1973- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1974 implement isinstance() and issubclass().
1975
1976- Py_BuildValue() now has a "D" conversion to create a Python complex
1977 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001978
Fred Drake4e262a92001-03-22 18:26:47 +00001979- Extensions types which support weak references must now set the
1980 field allocated for the weak reference machinery to NULL themselves;
1981 this is done to avoid the cost of checking each object for having a
1982 weakly referencable type in PyObject_INIT(), since most types are
1983 not weakly referencable.
1984
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001985- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1986 free variables and cell variables to and from the frame's f_locals.
1987
1988- Variants of several functions defined in pythonrun.h have been added
1989 to support the nested_scopes future statement. The variants all end
1990 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1991 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1992 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001993 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001994
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001995Distutils
1996
1997- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1998 into the release tree.
1999
Tim Peters0e57abf2001-05-02 07:39:38 +00002000- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002001 (an uninstaller, more customization of the installer's display)
2002
2003- from Jack Jansen: added Mac-specific code to generate a dialog for
2004 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002005 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002006 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002007
2008- added 'platforms' and 'keywords' to the set of metadata that can be
2009 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002010
2011- applied patches from Jason Tishler to make the compiler class work with
2012 Cygwin.
2013
2014
Tim Peters2fe289a2001-03-01 22:19:38 +00002015What's New in Python 2.1 beta 1?
2016================================
Tim Petersd66595f2001-02-04 03:09:53 +00002017
2018Core language, builtins, and interpreter
2019
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002020- Following an outcry from the community about the amount of code
2021 broken by the nested scopes feature introduced in 2.1a2, we decided
2022 to make this feature optional, and to wait until Python 2.2 (or at
2023 least 6 months) to make it standard. The option can be enabled on a
2024 per-module basis by adding "from __future__ import nested_scopes" at
2025 the beginning of a module (before any other statements, but after
2026 comments and an optional docstring). See PEP 236 (Back to the
2027 __future__) for a description of the __future__ statement. PEP 227
2028 (Statically Nested Scopes) has been updated to reflect this change,
2029 and to clarify the semantics in a number of endcases.
2030
2031- The nested scopes code, when enabled, has been hardened, and most
2032 bugs and memory leaks in it have been fixed.
2033
2034- Compile-time warnings are now generated for a number of conditions
2035 that will break or change in meaning when nested scopes are enabled:
2036
2037 - Using "from...import *" or "exec" without in-clause in a function
2038 scope that also defines a lambda or nested function with one or
2039 more free (non-local) variables. The presence of the import* or
2040 bare exec makes it impossible for the compiler to determine the
2041 exact set of local variables in the outer scope, which makes it
2042 impossible to determine the bindings for free variables in the
2043 inner scope. To avoid the warning about import *, change it into
2044 an import of explicitly name object, or move the import* statement
2045 to the global scope; to avoid the warning about bare exec, use
2046 exec...in... (a good idea anyway -- there's a possibility that
2047 bare exec will be deprecated in the future).
2048
2049 - Use of a global variable in a nested scope with the same name as a
2050 local variable in a surrounding scope. This will change in
2051 meaning with nested scopes: the name in the inner scope will
2052 reference the variable in the outer scope rather than the global
2053 of the same name. To avoid the warning, either rename the outer
2054 variable, or use a global statement in the inner function.
2055
Neil Schemenauera35c6882001-02-27 04:45:05 +00002056- An optional object allocator has been included. This allocator is
2057 optimized for Python objects and should be faster and use less memory
2058 than the standard system allocator. It is not enabled by default
2059 because of possible thread safety problems. The allocator is only
2060 protected by the Python interpreter lock and it is possible that some
2061 extension modules require a thread safe allocator. The object
2062 allocator can be enabled by providing the "--with-pymalloc" option to
2063 configure.
2064
Tim Petersd66595f2001-02-04 03:09:53 +00002065Standard library
2066
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002067- pyexpat now detects the expat version if expat.h defines it. A
2068 number of additional handlers are provided, which are only available
2069 since expat 1.95. In addition, the methods SetParamEntityParsing and
2070 GetInputContext of Parser objects are available with 1.95.x
2071 only. Parser objects now provide the ordered_attributes and
2072 specified_attributes attributes. A new module expat.model was added,
2073 which offers a number of additional constants if 1.95.x is used.
2074
2075- xml.dom offers the new functions registerDOMImplementation and
2076 getDOMImplementation.
2077
2078- xml.dom.minidom offers a toprettyxml method. A number of DOM
2079 conformance issues have been resolved. In particular, Element now
2080 has an hasAttributes method, and the handling of namespaces was
2081 improved.
2082
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002083- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2084 getting information about live Python code, and pydoc.py, a module
2085 for interactively converting docstrings to HTML or text.
2086 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002087 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002088 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2089 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002090
Tim Peters1eff7962001-03-01 02:31:33 +00002091- New library module difflib.py, primarily packaging the SequenceMatcher
2092 class at the heart of the popular ndiff.py file-comparison tool.
2093
2094- doctest.py (a framework for verifying Python code examples in docstrings)
2095 is now part of the std library.
2096
Tim Petersd66595f2001-02-04 03:09:53 +00002097Windows changes
2098
Guido van Rossume3955a82001-03-02 14:05:59 +00002099- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2100 small GUI that lets you browse the module docstrings using your
2101 default web browser.
2102
Tim Peters1eff7962001-03-01 02:31:33 +00002103- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2104 Platforms) is implemented. See
2105
2106 http://python.sourceforge.net/peps/pep-0235.html
2107
2108 for full details, especially the "Current Lower-Left Semantics" section.
2109 The new Windows import rules are simpler than before:
2110
2111 A. If the PYTHONCASEOK environment variable exists, same as
2112 before: silently accept the first case-insensitive match of any
2113 kind; raise ImportError if none found.
2114
2115 B. Else search sys.path for the first case-sensitive match; raise
2116 ImportError if none found.
2117
2118 The same rules have been implented on other platforms with case-
2119 insensitive but case-preserving filesystems too (including Cygwin, and
2120 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002121
Tim Peters25a9ce32001-02-19 07:06:36 +00002122- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2123 what it's supposed to do (and does do under NT and 2000) via direct
2124 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002125 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002126 all Win9x systems before.
2127
Tim Peters1eff7962001-03-01 02:31:33 +00002128- Build: Subproject _test (effectively) renamed to _testcapi.
2129
Tim Peters2fe289a2001-03-01 22:19:38 +00002130New platforms
2131
2132- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2133 Thanks to Steven Majewski!
2134
2135- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2136 Tishler!
2137
Guido van Rossum9089b272001-03-02 06:49:50 +00002138- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2139 Schwertberger! See RISCOS/README for more information -- it seems
2140 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002141 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002142
Tim Peters25a9ce32001-02-19 07:06:36 +00002143
Tim Petersd7b5e882001-01-25 03:36:26 +00002144What's New in Python 2.1 alpha 2?
2145=================================
Tim Peters40ead762001-01-27 05:35:26 +00002146
Tim Petersd7b5e882001-01-25 03:36:26 +00002147Core language, builtins, and interpreter
2148
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002149- Scopes nest. If a name is used in a function or class, but is not
2150 local, the definition in the nearest enclosing function scope will
2151 be used. One consequence of this change is that lambda statements
2152 could reference variables in the namespaces where the lambda is
2153 defined. In some unusual cases, this change will break code.
2154
2155 In all previous version of Python, names were resolved in exactly
2156 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002157 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002158 function A is defined within a function B, the names bound in B are
2159 not visible in A. The new rules make names bound in B visible in A,
2160 unless A contains a name binding that hides the binding in B.
2161
2162 Section 4.1 of the reference manual describes the new scoping rules
2163 in detail. The test script in Lib/test/test_scope.py demonstrates
2164 some of the effects of the change.
2165
2166 The new rules will cause existing code to break if it defines nested
2167 functions where an outer function has local variables with the same
2168 name as globals or builtins used by the inner function. Example:
2169
2170 def munge(str):
2171 def helper(x):
2172 return str(x)
2173 if type(str) != type(''):
2174 str = helper(str)
2175 return str.strip()
2176
2177 Under the old rules, the name str in helper() is bound to the
2178 builtin function str(). Under the new rules, it will be bound to
2179 the argument named str and an error will occur when helper() is
2180 called.
2181
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002182- The compiler will report a SyntaxError if "from ... import *" occurs
2183 in a function or class scope. The language reference has documented
2184 that this case is illegal, but the compiler never checked for it.
2185 The recent introduction of nested scope makes the meaning of this
2186 form of name binding ambiguous. In a future release, the compiler
2187 may allow this form when there is no possibility of ambiguity.
2188
Tim Peters40ead762001-01-27 05:35:26 +00002189- repr(string) is easier to read, now using hex escapes instead of octal,
2190 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2191
2192 >>> "\texample \r\n" + chr(0) + chr(255)
2193 '\texample \r\n\x00\xff' # in 2.1
2194 '\011example \015\012\000\377' # in 2.0
2195
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002196- Functions are now compared and hashed by identity, not by value, since
2197 the func_code attribute is writable.
2198
Fred Drakefb9d7122001-02-01 20:00:40 +00002199- Weak references (PEP 205) have been added. This involves a few
2200 changes in the core, an extension module (_weakref), and a Python
2201 module (weakref). The weakref module is the public interface. It
2202 includes support for "explicit" weak references, proxy objects, and
2203 mappings with weakly held values.
2204
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002205- A 'continue' statement can now appear in a try block within the body
2206 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002207 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002208
Tim Petersd7b5e882001-01-25 03:36:26 +00002209Standard library
2210
Barry Warsaw30dbd142001-01-31 22:14:01 +00002211- mailbox.py now has a new class, PortableUnixMailbox which is
2212 identical to UnixMailbox but uses a more portable scheme for
2213 determining From_ separators. Also, the constructors for all the
2214 classes in this module have a new optional `factory' argument, which
2215 is a callable used when new message classes must be instantiated by
2216 the next() method.
2217
Tim Petersd7b5e882001-01-25 03:36:26 +00002218- random.py is now self-contained, and offers all the functionality of
2219 the now-deprecated whrandom.py. See the docs for details. random.py
2220 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002221 and restoring the internal state of the generator; and jumpahead(n),
2222 for quickly forcing the internal state to be the same as if n calls to
2223 random() had been made. The latter is particularly useful for multi-
2224 threaded programs, creating one instance of the random.Random() class for
2225 each thread, then using .jumpahead() to force each instance to use a
2226 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002227
Tim Peters0de88fc2001-02-01 04:59:18 +00002228- random.py's seed() function is new. For bit-for-bit compatibility with
2229 prior releases, use the whseed function instead. The new seed function
2230 addresses two problems: (1) The old function couldn't produce more than
2231 about 2**24 distinct internal states; the new one about 2**45 (the best
2232 that can be done in the Wichmann-Hill generator). (2) The old function
2233 sometimes produced identical internal states when passed distinct
2234 integers, and there was no simple way to predict when that would happen;
2235 the new one guarantees to produce distinct internal states for all
2236 arguments in [0, 27814431486576L).
2237
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002238- The socket module now supports raw packets on Linux. The socket
2239 family is AF_PACKET.
2240
Tim Peters9ea17ac2001-02-02 05:57:15 +00002241- test_capi.py is a start at running tests of the Python C API. The tests
2242 are implemented by the new Modules/_testmodule.c.
2243
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002244- A new extension module, _symtable, provides provisional access to the
2245 internal symbol table used by the Python compiler. A higher-level
2246 interface will be added on top of _symtable in a future release.
2247
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002248- Removed the obsolete soundex module.
2249
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002250- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2251 the isSameNode method; NamedNodeMap the get method.
2252
2253- xml.sax.expatreader supports the lexical handler property; it
2254 generates comment, startCDATA, and endCDATA events.
2255
Tim Petersee826f82001-01-31 19:39:44 +00002256Windows changes
2257
2258- Build procedure: the zlib project is built in a different way that
2259 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002260 the zlib binary used. See PCbuild\readme.txt for details. Your old
2261 zlib-related directories can be deleted; you'll need to download fresh
2262 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002263
Tim Peters9ea17ac2001-02-02 05:57:15 +00002264- Build: New subproject _test for the benefit of test_capi.py (see above).
2265
Tim Petersb16c56f2001-02-02 21:24:51 +00002266- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2267 interface to some Python compiler internals).
2268
2269- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002270 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002271
Tim Petersa3a3a032000-11-30 05:22:44 +00002272What's New in Python 2.1 alpha 1?
2273=================================
2274
2275Core language, builtins, and interpreter
2276
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002277- There is a new Unicode companion to the PyObject_Str() API
2278 called PyObject_Unicode(). It behaves in the same way as the
2279 former, but assures that the returned value is an Unicode object
2280 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002281
Guido van Rossumf98eda02001-01-17 15:54:45 +00002282- The comparison operators support "rich comparison overloading" (PEP
2283 207). C extension types can provide a rich comparison function in
2284 the new tp_richcompare slot in the type object. The cmp() function
2285 and the C function PyObject_Compare() first try the new rich
2286 comparison operators before trying the old 3-way comparison. There
2287 is also a new C API PyObject_RichCompare() (which also falls back on
2288 the old 3-way comparison, but does not constrain the outcome of the
2289 rich comparison to a Boolean result).
2290
2291 The rich comparison function takes two objects (at least one of
2292 which is guaranteed to have the type that provided the function) and
2293 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2294 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2295 object, which may be NotImplemented (in which case the tp_compare
2296 slot function is used as a fallback, if defined).
2297
2298 Classes can overload individual comparison operators by defining one
2299 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002300 __ge__. There are no explicit "reflected argument" versions of
2301 these; instead, __lt__ and __gt__ are each other's reflection,
2302 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2303 reflection (similar at the C level). No other implications are
2304 made; in particular, Python does not assume that == is the Boolean
2305 inverse of !=, or that < is the Boolean inverse of >=. This makes
2306 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002307
2308 Classes or types that want to implement (in)equality tests but not
2309 the ordering operators (i.e. unordered types) should implement ==
2310 and !=, and raise an error for the ordering operators.
2311
Guido van Rossuma88479f2001-01-18 14:28:08 +00002312 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002313 Boolean; e.g. a matrix type might want to return a matrix of bits
2314 for A < B, giving elementwise comparisons. Such types should ensure
2315 that any interpretation of their value in a Boolean context raises
2316 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2317 at the C level) to always raise an exception.
2318
Guido van Rossuma88479f2001-01-18 14:28:08 +00002319- Complex numbers use rich comparisons to define == and != but raise
2320 an exception for <, <=, > and >=. Unfortunately, this also means
2321 that cmp() of two complex numbers raises an exception when the two
2322 numbers differ. Since it is not mathematically meaningful to compare
2323 complex numbers except for equality, I hope that this doesn't break
2324 too much code.
2325
Tim Peters3389f192001-02-18 08:48:49 +00002326- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002327 not defined by the language, other than that it's arbitrary but
2328 consistent (see the Reference Manual). An implementation detail changed
2329 in 2.1a1 such that None now compares less than any other object. Code
2330 relying on this new behavior (like code that relied on the previous
2331 behavior) does so at its own risk.
2332
Barry Warsaw573b5412001-01-15 20:43:18 +00002333- Functions and methods now support getting and setting arbitrarily
2334 named attributes (PEP 232). Functions have a new __dict__
2335 (a.k.a. func_dict) which hold the function attributes. Methods get
2336 and set attributes on their underlying im_func. It is a TypeError
2337 to set an attribute on a bound method.
2338
Guido van Rossum051e3352001-01-15 19:11:10 +00002339- The xrange() object implementation has been improved so that
2340 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2341 limitation that in this case len(xrange(sys.maxint)) can't be
2342 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2343 work fine as long as the index i doesn't actually reach 2**31.
2344 (Python uses regular ints for sequence and string indices; fixing
2345 that is much more work.)
2346
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002347- Two changes to from...import:
2348
Guido van Rossumba381232001-02-03 15:06:40 +00002349 1) "from M import X" now works even if (after loading module M)
2350 sys.modules['M'] is not a real module; it's basically a getattr()
2351 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002352
2353 2) "from M import *" now looks for M.__all__ to decide which names to
2354 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2355 filters out names starting with '_' as before. Whether or not
2356 __all__ exists, there's no restriction on the type of M.
2357
Guido van Rossumf61f1662001-01-10 20:13:55 +00002358- File objects have a new method, xreadlines(). This is the fastest
2359 way to iterate over all lines in a file:
2360
2361 for line in file.xreadlines():
2362 ...do something to line...
2363
2364 See the xreadlines module (mentioned below) for how to do this for
2365 other file-like objects.
2366
2367- Even if you don't use file.xreadlines(), you may expect a speedup on
2368 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002369 quite a bit in platform-specific ways: on systems (like Linux) that
2370 support flockfile(), getc_unlocked(), and funlockfile(), those are
2371 used by default. On systems (like Windows) without getc_unlocked(),
2372 a complicated (but still thread-safe) method using fgets() is used by
2373 default.
2374
Tim Petersd52269b2001-01-25 06:23:18 +00002375 You can force use of the fgets() method by #define'ing
2376 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002377 getc_unlocked()).
2378
Tim Petersd52269b2001-01-25 06:23:18 +00002379 You can force fgets() not to be used by #define'ing
2380 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002381 test_bufio.py fails -- and let us know if it does!).
2382
2383- In addition, the fileinput module, while still slower than the other
2384 methods on most platforms, has been sped up too, by using
2385 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002386
2387- Support for run-time warnings has been added, including a new
2388 command line option (-W) to specify the disposition of warnings.
2389 See the description of the warnings module below.
2390
2391- Extensive changes have been made to the coercion code. This mostly
2392 affects extension modules (which can now implement mixed-type
2393 numerical operators without having to use coercion), but
2394 occasionally, in boundary cases the coercion semantics have changed
2395 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002396 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002397 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002398 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002399
Guido van Rossumf98eda02001-01-17 15:54:45 +00002400- In connection with the coercion changes, a new built-in singleton
2401 object, NotImplemented is defined. This can be returned for
2402 operations that wish to indicate they are not implemented for a
2403 particular combination of arguments. From C, this is
2404 Py_NotImplemented.
2405
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002406- The interpreter accepts now bytecode files on the command line even
2407 if they do not have a .pyc or .pyo extension. On Linux, after executing
2408
Martin v. Löwise214baa2001-02-04 22:37:56 +00002409import imp,sys,string
2410magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2411reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2412open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002413
2414 any byte code file can be used as an executable (i.e. as an argument
2415 to execve(2)).
2416
Tim Peters9940b802000-12-01 07:59:35 +00002417- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002418 character. In 1.6 and earlier, they never produced a sign,
2419 and raised an error if the value of the long was too large
2420 to fit in a Python int. In 2.0, they produced a sign if and
2421 only if too large to fit in an int. This was inconsistent
2422 across platforms (because the size of an int varies across
2423 platforms), and inconsistent with hex() and oct(). Example:
2424
2425 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002426 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002427 'ffffffbe' # in 2.0 and before, on 32-bit machines
2428 >>> hex(-0x42L)
2429 '-0x42L' # in all versions of Python
2430
Tim Peters9940b802000-12-01 07:59:35 +00002431 The behavior of %d formats for negative Python longs remains
2432 the same as in 2.0 (although in 1.6 and before, they raised
2433 an error if the long didn't fit in a Python int).
2434
2435 %u formats don't make sense for Python longs, but are allowed
2436 and treated the same as %d in 2.1. In 2.0, a negative long
2437 formatted via %u produced a sign if and only if too large to
2438 fit in an int. In 1.6 and earlier, a negative long formatted
2439 via %u raised an error if it was too big to fit in an int.
2440
Guido van Rossum3661d392000-12-12 22:10:31 +00002441- Dictionary objects have an odd new method, popitem(). This removes
2442 an arbitrary item from the dictionary and returns it (in the form of
2443 a (key, value) pair). This can be useful for algorithms that use a
2444 dictionary as a bag of "to do" items and repeatedly need to pick one
2445 item. Such algorithms normally end up running in quadratic time;
2446 using popitem() they can usually be made to run in linear time.
2447
Tim Peters36cdad12000-12-29 02:06:45 +00002448Standard library
2449
Thomas Woutersfe385252001-01-19 23:16:56 +00002450- In the time module, the time argument to the functions strftime,
2451 localtime, gmtime, asctime and ctime is now optional, defaulting to
2452 the current time (in the local timezone).
2453
Guido van Rossumda91f222001-01-15 16:36:08 +00002454- The ftplib module now defaults to passive mode, which is deemed a
2455 more useful default given that clients are often inside firewalls
2456 these days. Note that this could break if ftplib is used to connect
2457 to a *server* that is inside a firewall, from outside; this is
2458 expected to be a very rare situation. To fix that, you can call
2459 ftp.set_pasv(0).
2460
Martin v. Löwis10a27872001-01-13 09:54:41 +00002461- The module site now treats .pth files not only for path configuration,
2462 but also supports extensions to the initialization code: Lines starting
2463 with import are executed.
2464
Guido van Rossumf61f1662001-01-10 20:13:55 +00002465- There's a new module, warnings, which implements a mechanism for
2466 issuing and filtering warnings. There are some new built-in
2467 exceptions that serve as warning categories, and a new command line
2468 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2469 turns warnings into errors). warnings.warn(message[, category])
2470 issues a warning message; this can also be called from C as
2471 PyErr_Warn(category, message).
2472
2473- A new module xreadlines was added. This exports a single factory
2474 function, xreadlines(). The intention is that this code is the
2475 absolutely fastest way to iterate over all lines in an open
2476 file(-like) object:
2477
2478 import xreadlines
2479 for line in xreadlines.xreadlines(file):
2480 ...do something to line...
2481
2482 This is equivalent to the previous the speed record holder using
2483 file.readlines(sizehint). Note that if file is a real file object
2484 (as opposed to a file-like object), this is equivalent:
2485
2486 for line in file.xreadlines():
2487 ...do something to line...
2488
Tim Peters36cdad12000-12-29 02:06:45 +00002489- The bisect module has new functions bisect_left, insort_left,
2490 bisect_right and insort_right. The old names bisect and insort
2491 are now aliases for bisect_right and insort_right. XXX_right
2492 and XXX_left methods differ in what happens when the new element
2493 compares equal to one or more elements already in the list: the
2494 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002495 right. Code that doesn't care where equal elements end up should
2496 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002497
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002498- The new curses.panel module wraps the panel library that forms part
2499 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2500
Guido van Rossumf61f1662001-01-10 20:13:55 +00002501- The SocketServer module now sets the allow_reuse_address flag by
2502 default in the TCPServer class.
2503
2504- A new function, sys._getframe(), returns the stack frame pointer of
2505 the caller. This is intended only as a building block for
2506 higher-level mechanisms such as string interpolation.
2507
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002508- The pyexpat module supports a number of new handlers, which are
2509 available only in expat 1.2. If invocation of a callback fails, it
2510 will report an additional frame in the traceback. Parser objects
2511 participate now in garbage collection. If expat reports an unknown
2512 encoding, pyexpat will try to use a Python codec; that works only
2513 for single-byte charsets. The parser type objects is exposed as
2514 XMLParserObject.
2515
2516- xml.dom now offers standard definitions for symbolic node type and
2517 exception code constants, and a hierarchy of DOM exceptions. minidom
2518 was adjusted to use them.
2519
2520- The conformance of xml.dom.minidom to the DOM specification was
2521 improved. It detects a number of additional error cases; the
2522 previous/next relationship works even when the tree is modified;
2523 Node supports the normalize() method; NamedNodeMap, DocumentType and
2524 DOMImplementation classes were added; Element supports the
2525 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2526 method.
2527
Guido van Rossumf61f1662001-01-10 20:13:55 +00002528Build issues
2529
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002530- For Unix (and Unix-compatible) builds, configuration and building of
2531 extension modules is now greatly automated. Rather than having to
2532 edit the Modules/Setup file to indicate which modules should be
2533 built and where their include files and libraries are, a
2534 distutils-based setup.py script now takes care of building most
2535 extension modules. All extension modules built this way are built
2536 as shared libraries. Only a few modules that must be linked
2537 statically are still listed in the Setup file; you won't need to
2538 edit their configuration.
2539
2540- Python should now build out of the box on Cygwin. If it doesn't,
2541 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002542
2543- Python now always uses its own (renamed) implementation of getopt()
2544 -- there's too much variation among C library getopt()
2545 implementations.
2546
2547- C++ compilers are better supported; the CXX macro is always set to a
2548 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002549
Tim Petersd92dfe02000-12-12 01:18:41 +00002550Windows changes
2551
2552- select module: By default under Windows, a select() call
2553 can specify no more than 64 sockets. Python now boosts
2554 this Microsoft default to 512. If you need even more than
2555 that, see the MS docs (you'll need to #define FD_SETSIZE
2556 and recompile Python from source).
2557
Guido van Rossumf61f1662001-01-10 20:13:55 +00002558- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2559 subdirectory is no more!
2560
Tim Petersa3a3a032000-11-30 05:22:44 +00002561
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002562What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002563=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002564
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002565Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002566changes are in the file HISTORY. If you are making the jump directly
2567from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2568HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002569
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002570Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2571the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2572http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002573
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002574--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002575
2576======================================================================
2577
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002578What's new in 2.0 (since release candidate 1)?
2579==============================================
2580
2581Standard library
2582
2583- The copy_reg module was modified to clarify its intended use: to
2584 register pickle support for extension types, not for classes.
2585 pickle() will raise a TypeError if it is passed a class.
2586
2587- Fixed a bug in gettext's "normalize and expand" code that prevented
2588 it from finding an existing .mo file.
2589
2590- Restored support for HTTP/0.9 servers in httplib.
2591
Tim Peters989b7b92000-10-16 20:24:53 +00002592- The math module was changed to stop raising OverflowError in case of
2593 underflow, and return 0 instead in underflow cases. Whether Python
2594 used to raise OverflowError in case of underflow was platform-
2595 dependent (it did when the platform math library set errno to ERANGE
2596 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002597
2598- Fixed a bug in StringIO that occurred when the file position was not
2599 at the end of the file and write() was called with enough data to
2600 extend past the end of the file.
2601
2602- Fixed a bug that caused Tkinter error messages to get lost on
2603 Windows. The bug was fixed by replacing direct use of
2604 interp->result with Tcl_GetStringResult(interp).
2605
2606- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2607 redirect response.
2608
2609- Several changes were made to distutils: Some debugging code was
2610 removed from util. Fixed the installer used when an external zip
2611 program (like WinZip) is not found; the source code for this
2612 installer is in Misc/distutils. check_lib() was modified to behave
2613 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2614 test for whether installed modules are on sys.path was changed to
2615 use both normcase() and normpath().
2616
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002617- Several minor bugs were fixed in the xml package (the minidom,
2618 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002619
2620- The regression test driver (regrtest.py) behavior when invoked with
2621 -l changed: It now reports a count of objects that are recognized as
2622 garbage but not freed by the garbage collector.
2623
Tim Peters989b7b92000-10-16 20:24:53 +00002624- The regression test for the math module was changed to test
2625 exceptional behavior when the test is run in verbose mode. Python
2626 cannot yet guarantee consistent exception behavior across platforms,
2627 so the exception part of test_math is run only in verbose mode, and
2628 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002629
2630Internals
2631
2632- PyOS_CheckStack() has been disabled on Win64, where it caused
2633 test_sre to fail.
2634
2635Build issues
2636
2637- Changed compiler flags, so that gcc is always invoked with -Wall and
2638 -Wstrict-prototypes. Users compiling Python with GCC should see
2639 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002640 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002641 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002642
Tim Petersa3a3a032000-11-30 05:22:44 +00002643- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002644
2645Tools and other miscellany
2646
2647- The compiler in Tools/compiler was updated to support the new
2648 language features introduced in 2.0: extended print statement, list
2649 comprehensions, and augmented assignments. The new compiler should
2650 also be backwards compatible with Python 1.5.2; the compiler will
2651 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002652 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002653
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002654What's new in 2.0 release candidate 1 (since beta 2)?
2655=====================================================
2656
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002657What is release candidate 1?
2658
2659We believe that release candidate 1 will fix all known bugs that we
2660intend to fix for the 2.0 final release. This release should be a bit
2661more stable than the previous betas. We would like to see even more
2662widespread testing before the final release, so we are producing this
2663release candidate. The final release will be exactly the same unless
2664any show-stopping (or brown bag) bugs are found by testers of the
2665release candidate.
2666
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002667All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002668to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002669
2670Core language, builtins, and interpreter
2671
2672- A bug that caused crashes when __coerce__ was used with augmented
2673 assignment, e.g. +=, was fixed.
2674
2675- Raise ZeroDivisionError when raising zero to a negative number,
2676 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2677 power operator and the result of math.pow(0.0, -2.0) will vary by
2678 platform. On Linux, it raises a ValueError.
2679
2680- A bug in Unicode string interpolation was fixed that occasionally
2681 caused errors with formats including "%%". For example, the
2682 following expression "%% %s" % u"abc" no longer raises a TypeError.
2683
2684- Compilation of deeply nested expressions raises MemoryError instead
2685 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2686
2687- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2688 rendering them useless. They are now written in binary mode again.
2689
2690Standard library
2691
2692- Keyword arguments are now accepted for most pattern and match object
2693 methods in SRE, the standard regular expression engine.
2694
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002695- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002696 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002697
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002698- Several bugs in the Unicode handling and error handling in _tkinter
2699 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002700
2701- Fix memory management errors in Merge() and Tkapp_Call() routines.
2702
2703- Several changes were made to cStringIO to make it compatible with
2704 the file-like object interface and with StringIO. If operations are
2705 performed on a closed object, an exception is raised. The truncate
2706 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002707 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002708
2709- There were many changes made to the linuxaudiodev module and its
2710 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002711 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002712
2713 Note that this module is named poorly, because it should work
2714 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002715 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002716
2717 The module now raises exceptions when errors occur instead of
2718 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2719 audio) and defines a getptr() method that calls the
2720 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2721
2722- The library_version attribute, introduced in an earlier beta, was
2723 removed because it can not be supported with early versions of the C
2724 readline library, which provides no way to determine the version at
2725 compile-time.
2726
2727- The binascii module is now enabled on Win64.
2728
Tim Peters46446d62000-10-09 21:19:31 +00002729- tokenize.py no longer suffers "recursion depth" errors when parsing
2730 programs with very long string literals.
2731
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002732Internals
2733
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002734- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002735 which is called when the interpreter starts up to determine where
2736 the standard library is installed. These vulnerabilities affect all
2737 previous versions of Python and can be exploited by setting very
2738 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2739 setuid Python script, although use of the wrapper in
2740 Misc/setuid-prog.c will eliminate the vulnerability.
2741
2742- Fixed garbage collection bugs in instance creation that were
2743 triggered when errors occurred during initialization. The solution,
2744 applied in cPickle and in PyInstance_New(), is to call
2745 PyObject_GC_Init() after the initialization of the object's
2746 container attributes is complete.
2747
2748- pyexpat adds definitions of PyModule_AddStringConstant and
2749 PyModule_AddObject if the Python version is less than 2.0, which
2750 provides compatibility with PyXML on Python 1.5.2.
2751
2752- If the platform has a bogus definition for LONG_BIT (the number of
2753 bits in a long), an error will be reported at compile time.
2754
2755- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2756 collection crashes and possibly other, unreported crashes.
2757
2758- Fixed a memory leak in _PyUnicode_Fini().
2759
2760Build issues
2761
2762- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002763 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002764 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002765
2766- The mmap.PAGESIZE constant is now initialized using sysconf when
2767 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2768
2769- The md5 file should now compile on all platforms.
2770
2771- The select module now compiles on platforms that do not define
2772 POLLRDNORM and related constants.
2773
2774- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002775 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002776
Jeremy Hylton10921202000-10-09 18:34:12 +00002777- BeOS: A number of changes were made to the build and installation
2778 process. ar-fake now operates on a directory of object files.
2779 dl_export.h is gone, and its macros now appear on the mwcc command
2780 line during build on PPC BeOS.
2781
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002782- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002783 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002784
2785- Cygwin: Support for shared libraries, Tkinter, and sockets.
2786
2787- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2788
2789Tools and other miscellany
2790
2791- Removed debugging prints from main used with freeze.
2792
Tim Peters46446d62000-10-09 21:19:31 +00002793- IDLE auto-indent no longer crashes when it encounters Unicode
2794 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002795
2796What's new in 2.0 beta 2 (since beta 1)?
2797========================================
2798
2799Core language, builtins, and interpreter
2800
Tim Peters482c0212000-09-26 06:33:09 +00002801- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002802 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002803
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002804- Add -h and -V command line options to print the usage message and
2805 Python version number and exit immediately.
2806
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002807- eval() and exec accept Unicode objects as code parameters.
2808
2809- getattr() and setattr() now also accept Unicode objects for the
2810 attribute name, which are converted to strings using the default
2811 encoding before lookup.
2812
2813- Multiplication on string and Unicode now does proper bounds
2814 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2815 string is too long."
2816
2817- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002818 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002819
Jeremy Hylton1b618592000-09-26 05:32:36 +00002820
2821Standard library and extensions
2822
Guido van Rossum5b08f132001-04-16 02:05:23 +00002823- socket module: the OpenSSL code now adds support for RAND_status()
2824 and EGD (Entropy Gathering Device).
2825
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002826- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002827 argument checking; it still takes no arguments.
2828
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002829- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002830
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002831- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002832
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002833- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002834
2835- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002836 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002837
2838- copy: Copy Unicode objects atomically.
2839
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002840- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002841
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002842- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002843
Fred Drake67233bc2000-09-26 16:40:27 +00002844- dbm: Add get() and setdefault() methods to dbm object. Add constant
2845 `library' to module that names the library used. Added doc strings
2846 and method names to error messages. Uses configure to determine
2847 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2848 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002849
2850- distutils: Update to version 0.9.3.
2851
2852- dl: Add several dl.RTLD_ constants.
2853
2854- fpectl: Now supported on FreeBSD.
2855
2856- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2857 found by the collector will be saved in gc.garbage. This is useful
2858 for debugging a program that creates reference cycles.
2859
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002860- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002861 of HTTP class. Do not close socket on zero-length response. Do not
2862 crash when server sends invalid content-length header.
2863
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002864- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002865
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002866- marshal: When reading a short, sign-extend on platforms where shorts
2867 are bigger than 16 bits. When reading a long, repair the unportable
2868 sign extension that was being done for 64-bit machines. (It assumed
2869 that signed right shift sign-extends.)
2870
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002871- operator: Add contains(), invert(), __invert__() as aliases for
2872 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002873
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002874- os: Add support for popen2() and popen3() on all platforms where
2875 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002876
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002877- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002878 clicking on a file in Explorer (or passing the file name to the
2879 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002880
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002881- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002882 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002883
2884- pickle: Now raises ValueError when an invalid pickle that contains
2885 a non-string repr where a string repr was expected. This behavior
2886 matches cPickle.
2887
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002888- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002889
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002890- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002891
2892- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002893 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002894 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002895
2896- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002897 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002898
2899- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002900 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002901 few cycles during startup since the first call to
2902 setdefaultencoding() will initialize the codec registry and the
2903 encodings package.
2904
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002905- socket: Support for size hint in readlines() method of object returned
2906 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002907
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002908- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002909 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002910 is followed by whitespace.
2911
Tim Petersa3a3a032000-11-30 05:22:44 +00002912- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002913
2914- struct: Check ranges for bytes and shorts.
2915
2916- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002917 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002918
2919- Tkinter: Image objects are now guaranteed to have unique ids. Set
2920 event.delta to zero if Tk version doesn't support mousewheel.
2921 Removed some debugging prints.
2922
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002923- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002924
Fred Drake67233bc2000-09-26 16:40:27 +00002925- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002926 which works around a bug in Norton AntiVirus 2000 that leads directly
2927 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002928
2929- xml: New version detection code allows PyXML to override standard
2930 XML package if PyXML version is greater than 0.6.1.
2931
Fred Drake64bb3802000-09-26 16:21:35 +00002932- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2933 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2934 tree only for nodes which are sufficiently interesting to a specific
2935 application. Does not provide the HTML-specific extensions. Still
2936 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002937
Fred Drake64bb3802000-09-26 16:21:35 +00002938- xml.sax: SAX 2 support for Python, including all the handler
2939 interfaces needed to process XML 1.0 compliant XML. Some
2940 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002941
Fred Drake64bb3802000-09-26 16:21:35 +00002942- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2943 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002944
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002945
Jeremy Hylton1b618592000-09-26 05:32:36 +00002946C API
2947
2948- Add three new convenience functions for module initialization --
2949 PyModule_AddObject(), PyModule_AddIntConstant(), and
2950 PyModule_AddStringConstant().
2951
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002952- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002953 removed and add #error to Python.h if NULL isn't defined after
2954 #include of stdio.h.
2955
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002956- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002957 backwards compatibility (at the source level) with old extensions.
2958
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002959- A wrapper API was added for signal() and sigaction(). Instead of
2960 either function, always use PyOS_getsig() to get a signal handler
2961 and PyOS_setsig() to set one. A new convenience typedef
2962 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002963
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002964- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002965 internal data buffer and size of a string object -- or the default
2966 encoded version of a Unicode object.
2967
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002968- PyString_Size() and PyString_AsString() accept Unicode objects.
2969
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002970- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002971 exists). INT_MAX and LONG_MAX will always be defined, even if
2972 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002973
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002974- PyFloat_FromString takes a second argument, pend, that was
2975 effectively useless. It is now officially useless but preserved for
2976 backwards compatibility. If the pend argument is not NULL, *pend is
2977 set to NULL.
2978
2979- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2980 for the attribute name. See note on getattr() above.
2981
2982- A few bug fixes to argument processing for Unicode.
2983 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2984 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2985 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002986 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002987
2988- Py_BuildValue accepts B format (for bgen-generated code).
2989
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002990
Jeremy Hylton1b618592000-09-26 05:32:36 +00002991Internals
2992
2993- On Unix, fix code for finding Python installation directory so that
2994 it works when argv[0] is a relative path.
2995
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002996- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002997 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002998 rather than by generating a copy of the object.
2999
Tim Peters482c0212000-09-26 06:33:09 +00003000- Several of the internal Unicode tables are much smaller now, and
3001 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003002
Jeremy Hylton97693b02000-09-26 17:42:51 +00003003- In the garbage collector: Fixed bug in collection of tuples. Fixed
3004 bug that caused some instances to be removed from the container set
3005 while they were still live. Fixed parsing in gc.set_debug() for
3006 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003007
3008- Fixed refcount problem in instance deallocation that only occurred
3009 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3010
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003011- On Windows, getpythonregpath is now protected against null data in
3012 registry key.
3013
3014- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003015 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003016
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003017
Jeremy Hylton1b618592000-09-26 05:32:36 +00003018Build and platform-specific issues
3019
3020- Better support of GNU Pth via --with-pth configure option.
3021
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003022- Python/C API now properly exposed to dynamically-loaded extension
3023 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024
3025- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3026 Don't define MS_SYNC to be zero when it is undefined. Added missing
3027 prototypes in posixmodule.c.
3028
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003029- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003030 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003031
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003032- Fix largefile support on older NetBSD systems and OpenBSD by adding
3033 define for TELL64.
3034
3035
3036Tools and other miscellany
3037
3038- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3039
3040- freeze: The modulefinder now works with 2.0 opcodes.
3041
Tim Petersa3a3a032000-11-30 05:22:44 +00003042- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003043 Move hackery of sys.argv until after the Tk instance has been
3044 created, which allows the application-specific Tkinter
3045 initialization to be executed if present; also pass an explicit
3046 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003047
Jeremy Hylton1b618592000-09-26 05:32:36 +00003048
3049What's new in 2.0 beta 1?
3050=========================
3051
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003052Source Incompatibilities
3053------------------------
3054
3055None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3056such as single-argument append(), connect() and bind(), and changes to
3057str(long) and repr(float).
3058
3059
3060Binary Incompatibilities
3061------------------------
3062
3063- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3064with Python 2.0; these extensions will have to be rebuilt for Python
30652.0.
3066
3067- On Windows, attempting to import a third party extension built for
3068Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3069can do about this. Check your PYTHONPATH environment variable!
3070
3071- Python bytecode files (*.pyc and *.pyo) are not compatible between
3072releases.
3073
3074
3075Overview of Changes Since 1.6
3076-----------------------------
3077
3078There are many new modules (including brand new XML support through
3079the xml package, and i18n support through the gettext module); a list
3080of all new modules is included below. Lots of bugs have been fixed.
3081
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003082The process for making major new changes to the language has changed
3083since Python 1.6. Enhancements must now be documented by a Python
3084Enhancement Proposal (PEP) before they can be accepted.
3085
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003086There are several important syntax enhancements, described in more
3087detail below:
3088
3089 - Augmented assignment, e.g. x += 1
3090
3091 - List comprehensions, e.g. [x**2 for x in range(10)]
3092
3093 - Extended import statement, e.g. import Module as Name
3094
3095 - Extended print statement, e.g. print >> file, "Hello"
3096
3097Other important changes:
3098
3099 - Optional collection of cyclical garbage
3100
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003101Python Enhancement Proposal (PEP)
3102---------------------------------
3103
3104PEP stands for Python Enhancement Proposal. A PEP is a design
3105document providing information to the Python community, or describing
3106a new feature for Python. The PEP should provide a concise technical
3107specification of the feature and a rationale for the feature.
3108
3109We intend PEPs to be the primary mechanisms for proposing new
3110features, for collecting community input on an issue, and for
3111documenting the design decisions that have gone into Python. The PEP
3112author is responsible for building consensus within the community and
3113documenting dissenting opinions.
3114
3115The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003116
3117Augmented Assignment
3118--------------------
3119
3120This must have been the most-requested feature of the past years!
3121Eleven new assignment operators were added:
3122
Guido van Rossume905e952000-09-05 12:42:46 +00003123 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003124
3125For example,
3126
3127 A += B
3128
3129is similar to
3130
3131 A = A + B
3132
3133except that A is evaluated only once (relevant when A is something
3134like dict[index].attr).
3135
3136However, if A is a mutable object, A may be modified in place. Thus,
3137if A is a number or a string, A += B has the same effect as A = A+B
3138(except A is only evaluated once); but if a is a list, A += B has the
3139same effect as A.extend(B)!
3140
3141Classes and built-in object types can override the new operators in
3142order to implement the in-place behavior; the not-in-place behavior is
3143used automatically as a fallback when an object doesn't implement the
3144in-place behavior. For classes, the method name is derived from the
3145method name for the corresponding not-in-place operator by inserting
3146an 'i' in front of the name, e.g. __iadd__ implements in-place
3147__add__.
3148
3149Augmented assignment was implemented by Thomas Wouters.
3150
3151
3152List Comprehensions
3153-------------------
3154
3155This is a flexible new notation for lists whose elements are computed
3156from another list (or lists). The simplest form is:
3157
3158 [<expression> for <variable> in <sequence>]
3159
Guido van Rossum56db0952000-09-06 23:34:25 +00003160For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003161This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003162
3163You can also add a condition:
3164
3165 [<expression> for <variable> in <sequence> if <condition>]
3166
3167For example, [w for w in words if w == w.lower()] would yield the list
3168of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003169than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003170
3171You can also have nested for loops and more than one 'if' clause. For
3172example, here's a function that flattens a sequence of sequences::
3173
3174 def flatten(seq):
3175 return [x for subseq in seq for x in subseq]
3176
3177 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3178
3179This prints
3180
3181 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3182
3183List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003184Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003185
3186
3187Extended Import Statement
3188-------------------------
3189
3190Many people have asked for a way to import a module under a different
3191name. This can be accomplished like this:
3192
3193 import foo
3194 bar = foo
3195 del foo
3196
3197but this common idiom gets old quickly. A simple extension of the
3198import statement now allows this to be written as follows:
3199
3200 import foo as bar
3201
3202There's also a variant for 'from ... import':
3203
3204 from foo import bar as spam
3205
3206This also works with packages; e.g. you can write this:
3207
3208 import test.regrtest as regrtest
3209
3210Note that 'as' is not a new keyword -- it is recognized only in this
3211context (this is only possible because the syntax for the import
3212statement doesn't involve expressions).
3213
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003214Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003215
3216
3217Extended Print Statement
3218------------------------
3219
3220Easily the most controversial new feature, this extension to the print
3221statement adds an option to make the output go to a different file
3222than the default sys.stdout.
3223
3224For example, to write an error message to sys.stderr, you can now
3225write:
3226
3227 print >> sys.stderr, "Error: bad dog!"
3228
3229As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003230evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003231
3232 print >> None, "Hello world"
3233
3234is equivalent to
3235
3236 print "Hello world"
3237
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003238Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003239
3240
3241Optional Collection of Cyclical Garbage
3242---------------------------------------
3243
3244Python is now equipped with a garbage collector that can hunt down
3245cyclical references between Python objects. It's no replacement for
3246reference counting; in fact, it depends on the reference counts being
3247correct, and decides that a set of objects belong to a cycle if all
3248their reference counts can be accounted for from their references to
3249each other. This devious scheme was first proposed by Eric Tiedemann,
3250and brought to implementation by Neil Schemenauer.
3251
3252There's a module "gc" that lets you control some parameters of the
3253garbage collection. There's also an option to the configure script
3254that lets you enable or disable the garbage collection. In 2.0b1,
3255it's on by default, so that we (hopefully) can collect decent user
3256experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003257performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003258off by default in the final 2.0 release.
3259
3260
3261Smaller Changes
3262---------------
3263
3264A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3265map(None, seq1, seq2, ...) when the sequences have the same length;
3266i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3267the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003268zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003269
3270sys.version_info is a tuple (major, minor, micro, level, serial).
3271
3272Dictionaries have an odd new method, setdefault(key, default).
3273dict.setdefault(key, default) returns dict[key] if it exists; if not,
3274it sets dict[key] to default and returns that value. Thus:
3275
3276 dict.setdefault(key, []).append(item)
3277
3278does the same work as this common idiom:
3279
3280 if not dict.has_key(key):
3281 dict[key] = []
3282 dict[key].append(item)
3283
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003284There are two new variants of SyntaxError that are raised for
3285indentation-related errors: IndentationError and TabError.
3286
3287Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3288escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003289
3290The limits on the size of expressions and file in Python source code
3291have been raised from 2**16 to 2**32. Previous versions of Python
3292were limited because the maximum argument size the Python VM accepted
3293was 2**16. This limited the size of object constructor expressions,
3294e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3295limit was raised thanks to a patch by Charles Waldman that effectively
3296fixes the problem. It is now much more likely that you will be
3297limited by available memory than by an arbitrary limit in Python.
3298
3299The interpreter's maximum recursion depth can be modified by Python
3300programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3301limit is the maximum number of recursive calls that can be made by
3302Python code. The limit exists to prevent infinite recursion from
3303overflowing the C stack and causing a core dump. The default value is
33041000. The maximum safe value for a particular platform can be found
3305by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003306
3307New Modules and Packages
3308------------------------
3309
3310atexit - for registering functions to be called when Python exits.
3311
3312imputil - Greg Stein's alternative API for writing custom import
3313hooks.
3314
3315pyexpat - an interface to the Expat XML parser, contributed by Paul
3316Prescod.
3317
3318xml - a new package with XML support code organized (so far) in three
3319subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3320would fill a volume. There's a special feature whereby a
3321user-installed package named _xmlplus overrides the standard
3322xmlpackage; this is intended to give the XML SIG a hook to distribute
3323backwards-compatible updates to the standard xml package.
3324
3325webbrowser - a platform-independent API to launch a web browser.
3326
3327
Guido van Rossume905e952000-09-05 12:42:46 +00003328Changed Modules
3329---------------
3330
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003331array -- new methods for array objects: count, extend, index, pop, and
3332remove
3333
3334binascii -- new functions b2a_hex and a2b_hex that convert between
3335binary data and its hex representation
3336
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003337calendar -- Many new functions that support features including control
3338over which day of the week is the first day, returning strings instead
3339of printing them. Also new symbolic constants for days of week,
3340e.g. MONDAY, ..., SUNDAY.
3341
3342cgi -- FieldStorage objects have a getvalue method that works like a
3343dictionary's get method and returns the value attribute of the object.
3344
3345ConfigParser -- The parser object has new methods has_option,
3346remove_section, remove_option, set, and write. They allow the module
3347to be used for writing config files as well as reading them.
3348
3349ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003350optionally support the RFC 959 REST command.
3351
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003352gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003353
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003354httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3355the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003356
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003357locale -- implement getdefaultlocale for Win32 and Macintosh
3358
3359marshal -- no longer dumps core when marshaling deeply nested or
3360recursive data structures
3361
3362os -- new functions isatty, seteuid, setegid, setreuid, setregid
3363
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003364os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3365support under Unix.
3366
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003367os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003368
3369os.path -- fix semantics of os.path.commonprefix
3370
3371smtplib -- support for sending very long messages
3372
3373socket -- new function getfqdn()
3374
3375readline -- new functions to read, write and truncate history files.
3376The readline section of the library reference manual contains an
3377example.
3378
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003379select -- add interface to poll system call
3380
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003381shutil -- new copyfileobj function
3382
3383SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3384HTTP server.
3385
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003386Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003387
3388urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003389e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003390
3391whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003392
3393
3394Obsolete Modules
3395----------------
3396
3397None. However note that 1.6 made a whole slew of modules obsolete:
3398stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3399poly, zmod, strop, util, whatsound.
3400
3401
3402Changed, New, Obsolete Tools
3403----------------------------
3404
Tim Peters8b092332000-09-05 20:15:25 +00003405None.
Guido van Rossume905e952000-09-05 12:42:46 +00003406
3407
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003408C-level Changes
3409---------------
3410
3411Several cleanup jobs were carried out throughout the source code.
3412
3413All C code was converted to ANSI C; we got rid of all uses of the
3414Py_PROTO() macro, which makes the header files a lot more readable.
3415
3416Most of the portability hacks were moved to a new header file,
3417pyport.h; several other new header files were added and some old
3418header files were removed, in an attempt to create a more rational set
3419of header files. (Few of these ever need to be included explicitly;
3420they are all included by Python.h.)
3421
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003422Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003423and Win64, especially for the new Intel Itanium processor. Mick also
3424added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003425
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003426The C APIs to return an object's size have been update to consistently
3427use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3428previous versions, the abstract interfaces used PyXXX_Length and the
3429concrete interfaces used PyXXX_Size. The old names,
3430e.g. PyObject_Length, are still available for backwards compatibility
3431at the API level, but are deprecated.
3432
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003433The PyOS_CheckStack function has been implemented on Windows by
3434Fredrik Lundh. It prevents Python from failing with a stack overflow
3435on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003436
3437The GC changes resulted in creation of two new slots on object,
3438tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003439the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003440
3441The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003442C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003443
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003444PyErr_Format has been updated to automatically calculate the size of
3445the buffer needed to hold the formatted result string. This change
3446prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003447
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003448New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003449
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003450PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3451that are the same as their non-Ex counterparts except they take an
3452extra flag argument that tells them to close the file when done.
3453
3454XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003455
Tim Peters8b092332000-09-05 20:15:25 +00003456
3457Windows Changes
3458---------------
3459
3460New popen2/popen3/peopen4 in os module (see Changed Modules above).
3461
3462os.popen is much more usable on Windows 95 and 98. See Microsoft
3463Knowledge Base article Q150956. The Win9x workaround described there
3464is implemented by the new w9xpopen.exe helper in the root of your
3465Python installation. Note that Python uses this internally; it is not
3466a standalone program.
3467
3468Administrator privileges are no longer required to install Python
3469on Windows NT or Windows 2000. If you have administrator privileges,
3470Python's registry info will be written under HKEY_LOCAL_MACHINE.
3471Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003472under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003473uses of Python, but will prevent some advanced uses from working
3474(for example, running a Python script as an NT service, or possibly
3475from CGI).
3476
3477[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3478installer; instead, it installs the needed Tcl/Tk files directly in the
3479Python directory. If you already have a Tcl/Tk installation, this
3480wastes some disk space (about 4 Megs) but avoids problems with
3481conflicting Tcl/Tk installations, and makes it much easier for Python
3482to ensure that Tcl/Tk can find all its files.
3483
3484[This was new in 1.6] The Windows installer now installs by default in
3485\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3486
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003487
3488Updates to the changes between 1.5.2 and 1.6
3489--------------------------------------------
3490
3491The 1.6 NEWS file can't be changed after the release is done, so here
3492is some late-breaking news:
3493
3494New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3495and changes to getlocale() and setlocale().
3496
3497The new module is now enabled per default.
3498
3499It is not true that the encodings codecs cannot be used for normal
3500strings: the string.encode() (which is also present on 8-bit strings
3501!) allows using them for 8-bit strings too, e.g. to convert files from
3502cp1252 (Windows) to latin-1 or vice-versa.
3503
3504Japanese codecs are available from Tamito KAJIYAMA:
3505http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3506
3507
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003508======================================================================