blob: 7275ad4895f9bd90817504ce10ddd739f17a0398 [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
Walter Dörwald474458d2002-06-04 15:16:29 +0000127- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
128 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
129 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
130 big endian systems were added to the codecs module. The old names
131 BOM32_* and BOM64_* were off by a factor of 2.
132
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000133- added degree/radian conversion functions to the math module.
134
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000135- ftplib.retrlines() now tests for callback is None rather than testing
136 for False. Was causing an error when given a callback object which
137 was callable but also returned len() as zero. The change may
138 create new breakage if the caller relied on the undocumented behavior
139 and called with callback set to [] or some other False value not
140 identical to None.
141
Tim Peters46c04e12002-05-05 20:40:00 +0000142- random.gauss() uses a piece of hidden state used by nothing else,
143 and the .seed() and .whseed() methods failed to reset it. In other
144 words, setting the seed didn't completely determine the sequence of
145 results produced by random.gauss(). It does now. Programs repeatedly
146 mixing calls to a seed method with calls to gauss() may see different
147 results now.
148
Fred Drake7f781c92002-05-01 20:33:53 +0000149- The pickle.Pickler class grew a clear_memo() method to mimic that
150 provided by cPickle.Pickler.
151
Tim Peters81b92512002-04-29 01:37:32 +0000152- difflib's SequenceMatcher class now does a dynamic analysis of
153 which elements are so frequent as to constitute noise. For
154 comparing files as sequences of lines, this generally works better
155 than the IS_LINE_JUNK function, and function ndiff's linejunk
156 argument defaults to None now as a result. A happy benefit is
157 that SequenceMatcher may run much faster now when applied
158 to large files with many duplicate lines (for example, C program
159 text with lots of repeated "}" and "return NULL;" lines).
160
Guido van Rossum256705b2002-04-23 13:29:43 +0000161- New Text.dump() method in Tkinter module.
162
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000163- New distutils commands for building packagers were added to
164 support pkgtool on Solaris and swinstall on HP-UX.
165
166- distutils now has a new abstract binary packager base class
167 command/bdist_packager, which simplifies writing packagers.
168 This will hopefully provide the missing bits to encourage
169 people to submit more packagers, e.g. for Debian, FreeBSD
170 and other systems.
171
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000172- The UTF-16, -LE and -BE now raise a NotImplementedError
173 for all calls to .readline(). Previously, they used to just
174 produce garbage or fail with an encoding error -- UTF-16 is
175 a 2-byte encoding and the C lib's line reading APIs don't
176 work well with these.
177
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000178- compileall now supports quiet operation.
179
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000180- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000181 connections.
182
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000183- socket module: the SSL support was broken out of the main
184 _socket module C helper and placed into a new _ssl helper
185 which now gets imported by socket.py if available and working.
186
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000187- encodings package: added aliases for all supported IANA character
188 sets
189
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000190- ftplib: to safeguard the user's privacy, anonymous login will use
191 "anonymous@" as default password, rather than the real user and host
192 name.
193
Fred Drake36736122002-01-10 13:50:31 +0000194- webbrowser: tightened up the command passed to os.system() so that
195 arbitrary shell code can't be executed because a bogus URL was
196 passed in.
197
Tim Peters11bd9942002-02-01 00:52:29 +0000198- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000199 gettext.find an optional all argument. Translations will now fallback
200 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000201
Martin v. Löwis9668b932002-01-12 11:27:42 +0000202- distutils bdist commands now offer a --skip-build option.
203
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000204- warnings.warn now accepts a Warning instance as first argument.
205
Fred Drakefed7e852002-04-04 19:36:15 +0000206- The xml.sax.expatreader.ExpatParser class will no longer create
207 circular references by using itself as the locator that gets passed
208 to the content handler implementation. [SF bug #535474]
209
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000210- The email.Parser.Parser class now properly parses strings regardless
211 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
212 or CRLF). Also, the Header class's constructor default arguments
213 has changed slightly so that an explicit maxlinelen value is always
214 honored.
215
Tim Petersaf8446f2001-12-21 21:36:50 +0000216Tools/Demos
217
Marc-André Lemburg46260092002-04-04 16:17:11 +0000218- freeze.py now produces binaries which can import shared modules,
219 unlike before when this failed due to missing symbol exports in
220 the generated binary.
221
Tim Petersaf8446f2001-12-21 21:36:50 +0000222Build
223
Tim Peters639295f2002-04-21 07:30:30 +0000224- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
225 say how or when to configure it, or how to turn it off.
226
Martin v. Löwis1142de32002-03-29 16:28:31 +0000227- On Unix, a shared libpython2.3.so can be created with --enable-shared.
228
Tim Peters8deda702002-03-30 10:06:07 +0000229- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
230 preprocessor symbols were eliminated. The internal decisions they
231 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000232
Fred Drake7d28b732002-05-02 21:17:00 +0000233- The tools used to build the documentation now work under Cygwin as
234 well as Unix.
235
Tim Petersaf8446f2001-12-21 21:36:50 +0000236C API
237
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000238- Added new macro PySequence_ITEM(o, i) that directly calls
239 sq_item without rechecking that o is a sequence and without
240 adjusting for negative indices.
241
Fred Draked0ba6362002-05-02 21:28:26 +0000242- PyRange_New() now raises ValueError if the fourth argument is not 1.
243 This is part of the removal of deprecated features of the xrange
244 object.
245
Guido van Rossum517c7d42002-04-26 02:49:14 +0000246- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
247 coercion if both arguments have the same type but this type has the
248 CHECKTYPES flag set. This is to better support proxies.
249
Neil Schemenauer9344b142002-04-12 23:00:08 +0000250- The type of tp_free has been changed from "void (*)(PyObject *)" to
251 "void (*)(void *)".
252
253- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
254
Guido van Rossum0986d822002-04-08 01:38:42 +0000255- A type can now inherit its metatype from its base type. Previously,
256 when PyType_Ready() was called, if ob_type was found to be NULL, it
257 was always set to &PyType_Type; now it is set to base->ob_type,
258 where base is tp_base, defaulting to &PyObject_Type.
259
260- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
261
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000262- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000263
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000264- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000265 without going through the buffer API.
266
Martin v. Löwis7198a522002-01-01 19:59:11 +0000267- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
268
Tim Peters10a3bb52001-12-25 19:07:38 +0000269- An old #define of ANY as void has been removed from pyport.h. This
270 hasn't been used since Python's pre-ANSI days, and the #define has
271 been marked as obsolete since then. SF bug 495548 says it created
272 conflicts with other packages, so keeping it around wasn't harmless.
273
Tim Petersaf8446f2001-12-21 21:36:50 +0000274- Because Python's magic number scheme broke on January 1st, we decided
275 to stop Python development. Thanks for all the fish!
276
Tim Petersfb05db22002-03-11 00:24:00 +0000277- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000278 scheme to a new one. See Python/import.c for details.
279
Tim Petersaf8446f2001-12-21 21:36:50 +0000280New platforms
281
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000282- GNU/Hurd is now supported.
283
Tim Petersaf8446f2001-12-21 21:36:50 +0000284Tests
285
286Windows
287
Tim Peters08e72952002-04-16 20:48:01 +0000288- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
289 of that has been fixed in the installer (disabled Wise's "delete in-
290 use files" uninstall option).
291
Guido van Rossum181e41a2002-04-06 00:23:25 +0000292- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
293
Tim Peters33187922002-04-04 20:02:04 +0000294- The installer now installs Start menu shortcuts under (the local
295 equivalent of) "All Users" when doing an Admin install.
296
Tim Petersfb05db22002-03-11 00:24:00 +0000297- file.truncate([newsize]) now works on Windows for all newsize values.
298 It used to fail if newsize didn't fit in 32 bits, reflecting a
299 limitation of MS _chsize (which is no longer used).
300
Tim Petersab034fa2002-02-01 11:27:43 +0000301- os.waitpid() is now implemented for Windows, and can be used to block
302 until a specified process exits. This is similar to, but not exactly
303 the same as, os.waitpid() on POSIX systems. If you're waiting for
304 a specific process whose pid was obtained from one of the spawn()
305 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000306 See the docs for details. The docs were changed to clarify that
307 spawn functions return, and waitpid requires, a process handle on
308 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000309
Tim Peters11bd9942002-02-01 00:52:29 +0000310- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000311 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000312 to a nasty problem: before 2.3, if you got a temp file on Windows, it
313 got wrapped in an object whose close() method first closed the
314 underlying file, then deleted the file. This usually worked fine.
315 However, the spawn family of functions on Windows create (at a low C
316 level) the same set of open files in the spawned process Q as were
317 open in the spawning process P. If a temp file f was among them, then
318 doing f.close() in P first closed P's C-level file handle on f, but Q's
319 C-level file handle on f remained open, so the attempt in P to delete f
320 blew up with a "Permission denied" error (Windows doesn't allow
321 deleting open files). This was surprising, subtle, and difficult to
322 work around.
323
324- The os module now exports all the symbolic constants usable with the
325 low-level os.open() on Windows: the new constants in 2.3 are
326 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
327 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
328 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
329 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
330 (so specify both if you want both; note that neither is useful unless
331 specified with O_CREAT too).
332
Tim Petersaf8446f2001-12-21 21:36:50 +0000333Mac
334
335
Tim Peters909c0912001-12-14 23:16:18 +0000336What's New in Python 2.2 final?
337Release date: 21-Dec-2001
338===============================
339
340Type/class unification and new-style classes
341
Barry Warsaw52acb492001-12-21 20:04:22 +0000342- pickle.py, cPickle: allow pickling instances of new-style classes
343 with a custom metaclass.
344
Tim Peters909c0912001-12-14 23:16:18 +0000345Core and builtins
346
Barry Warsaw52acb492001-12-21 20:04:22 +0000347- weakref proxy object: when comparing, unwrap both arguments if both
348 are proxies.
349
Tim Peters909c0912001-12-14 23:16:18 +0000350Extension modules
351
Barry Warsaw52acb492001-12-21 20:04:22 +0000352- binascii.b2a_base64(): fix a potential buffer overrun when encoding
353 very short strings.
354
355- cPickle: the obscure "fast" mode was suspected of causing stack
356 overflows on the Mac. Hopefully fixed this by setting the recursion
357 limit much smaller. If the limit is too low (it only affects
358 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
359 when compiling cPickle.c (or in pyconfig.h).
360
Tim Peters909c0912001-12-14 23:16:18 +0000361Library
362
Barry Warsaw52acb492001-12-21 20:04:22 +0000363- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
364 close or delete time).
365
366- rfc822.py: fixed a bug where the address '<>' was converted to None
367 instead of an empty string (also fixes the email.Utils module).
368
369- xmlrpclib.py: version 1.0.0; uses precision for doubles.
370
371- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000372 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000373
Tim Peters909c0912001-12-14 23:16:18 +0000374Tools/Demos
375
376Build
377
378C API
379
380New platforms
381
382Tests
383
384Windows
385
Barry Warsaw52acb492001-12-21 20:04:22 +0000386- distutils package: fixed broken Windows installers (bdist_wininst).
387
388- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
389 instances are deleted at process exit time.
390
391- socket.py: prevent mysterious warnings when socket instances are
392 deleted at process exit time.
393
394- posixmodule.c: fix a Windows crash with stat() of a filename ending
395 in backslash.
396
Tim Peters909c0912001-12-14 23:16:18 +0000397Mac
398
Barry Warsaw52acb492001-12-21 20:04:22 +0000399- The Carbon toolbox modules have been upgraded to Universal Headers
400 3.4, and experimental CoreGraphics and CarbonEvents modules have
401 been added. All only for framework-enabled MacOSX.
402
Tim Peters909c0912001-12-14 23:16:18 +0000403
Tim Peters6272dfd2001-12-13 19:34:00 +0000404What's New in Python 2.2c1?
405Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000406===========================
407
408Type/class unification and new-style classes
409
Barry Warsaw06557452001-12-14 20:47:12 +0000410- Guido's tutorial introduction to the new type/class features has
411 been extensively updated. See
412
413 http://www.python.org/2.2/descrintro.html
414
415 That remains the primary documentation in this area.
416
Guido van Rossum33bab012001-12-05 22:45:48 +0000417- Fixed a leak: instance variables declared with __slots__ were never
418 deleted!
419
Guido van Rossum4b800852001-12-03 00:54:52 +0000420- The "delete attribute" method of descriptor objects is called
421 __delete__, not __del__. In previous releases, it was mistakenly
422 called __del__, which created an unfortunate overloading condition
423 with finalizers. (The "get attribute" and "set attribute" methods
424 are still called __get__ and __set__, respectively.)
425
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000426- Some subtle issues with the super built-in were fixed:
427
428 (a) When super itself is subclassed, its __get__ method would still
429 return an instance of the base class (i.e., of super).
430
431 (b) super(C, C()).__class__ would return C rather than super. This
432 is confusing. To fix this, I decided to change the semantics of
433 super so that it only applies to code attributes, not to data
434 attributes. After all, overriding data attributes is not
435 supported anyway.
436
437 (c) The __get__ method didn't check whether the argument was an
438 instance of the type used in creation of the super instance.
439
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000440- Previously, hash() of an instance of a subclass of a mutable type
441 (list or dictionary) would return some value, rather than raising
442 TypeError. This has been fixed. Also, directly calling
443 dict.__hash__ and list.__hash__ now raises the same TypeError
444 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000445
Guido van Rossumd331cb52001-12-05 19:46:42 +0000446- New-style objects now support deleting their __dict__. This is for
447 all intents and purposes equivalent to assigning a brand new empty
448 dictionary, but saves space if the object is not used further.
449
Tim Petersb3c9af12001-11-17 00:21:57 +0000450Core and builtins
451
Tim Peters3caca232001-12-06 06:23:26 +0000452- -Qnew now works as documented in PEP 238: when -Qnew is passed on
453 the command line, all occurrences of "/" use true division instead
454 of classic division. See the PEP for details. Note that "all"
455 means all instances in library and 3rd-party modules, as well as in
456 your own code. As the PEP says, -Qnew is intended for use only in
457 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000458 Note that test_coercion.py in the standard Python test suite fails
459 under -Qnew; this is expected, and won't be repaired until true
460 division becomes the default (in the meantime, test_coercion is
461 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000462
Fred Drake6c01e252001-12-14 17:08:12 +0000463- complex() now only allows the first argument to be a string
464 argument, and raises TypeError if either the second arg is a string
465 or if the second arg is specified when the first is a string.
466
Tim Petersb3c9af12001-11-17 00:21:57 +0000467Extension modules
468
Martin v. Löwis560da622001-11-24 09:24:51 +0000469- gc.get_referents was renamed to gc.get_referrers.
470
Tim Petersb3c9af12001-11-17 00:21:57 +0000471Library
472
Tim Peters25059d32001-12-07 20:35:43 +0000473- Functions in the os.spawn() family now release the global interpreter
474 lock around calling the platform spawn. They should always have done
475 this, but did not before 2.2c1. Multithreaded programs calling
476 an os.spawn function with P_WAIT will no longer block all Python threads
477 until the spawned program completes. It's possible that some programs
478 relies on blocking, although more likely by accident than by design.
479
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000480- webbrowser defaults to netscape.exe on OS/2 now.
481
Martin v. Löwis652e1912001-11-25 14:50:56 +0000482- Tix.ResizeHandle exposes detach_widget, hide, and show.
483
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000484- The charset alias windows_1252 has been added.
485
Barry Warsaw06557452001-12-14 20:47:12 +0000486- types.StringTypes is a tuple containing the defined string types;
487 usually this will be (str, unicode), but if Python was compiled
488 without Unicode support it will be just (str,).
489
490- The pulldom and minidom modules were synchronized to PyXML.
491
Tim Petersb3c9af12001-11-17 00:21:57 +0000492Tools/Demos
493
Barry Warsaw06557452001-12-14 20:47:12 +0000494- A new script called Tools/scripts/google.py was added, which fires
495 off a search on Google.
496
Tim Petersb3c9af12001-11-17 00:21:57 +0000497Build
498
Barry Warsaw06557452001-12-14 20:47:12 +0000499- Note that release builds of Python should arrange to define the
500 preprocessor symbol NDEBUG on the command line (or equivalent).
501 In the 2.2 pre-release series we tried to define this by magic in
502 Python.h instead, but it proved to cause problems for extension
503 authors. The Unix, Windows and Mac builds now all define NDEBUG in
504 release builds via cmdline (or equivalent) instead. Ports to
505 other platforms should do likewise.
506
Jack Jansen1999ef42001-12-06 21:47:20 +0000507- It is no longer necessary to use --with-suffix when building on a
508 case-insensitive file system (such as Mac OS X HFS+). In the build
509 directory an extension is used, but not in the installed python.
510
Tim Petersb3c9af12001-11-17 00:21:57 +0000511C API
512
Tim Petersf582b822001-12-11 18:51:08 +0000513- New function PyDict_MergeFromSeq2() exposes the builtin dict
514 constructor's logic for updating a dictionary from an iterable object
515 producing key-value pairs.
516
Tim Peterscffed4b2001-11-29 03:26:37 +0000517- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000518 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000519 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
520 dump core in some bad cases. This has been repaired. As a result,
521 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
522 previously went unchallenged.
523
Tim Petersb3c9af12001-11-17 00:21:57 +0000524New platforms
525
526Tests
527
528Windows
529
530Mac
531
Jack Jansenffa260f2001-12-06 21:14:00 +0000532- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
533 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000534
Barry Warsaw06557452001-12-14 20:47:12 +0000535- Changed logic for finding python home in Mac OS X framework Pythons.
536 Now sys.executable points to the executable again, in stead of to
537 the shared library. The latter is used only for locating the python
538 home.
539
540
Tim Peters84362bc2001-10-19 17:55:30 +0000541What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000542Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000543===========================
544
545Type/class unification and new-style classes
546
Guido van Rossum3d27df02001-11-15 20:27:54 +0000547- Multiple inheritance mixing new-style and classic classes in the
548 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000549
550 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000551 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000552
553 The MRO (method resolution order) for each base class is respected
554 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000555 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000556 This needs to be documented.
557
Tim Petersa427a2b2001-10-29 22:25:45 +0000558- The new builtin dictionary() constructor, and dictionary type, have
559 been renamed to dict. This reflects a decade of common usage.
560
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000561- dict() now accepts an iterable object producing 2-sequences. For
562 example, dict(d.items()) == d for any dictionary d. The argument,
563 and the elements of the argument, can be any iterable objects.
564
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000565- New-style classes can now have a __del__ method, which is called
566 when the instance is deleted (just like for classic classes).
567
Guido van Rossum12d955c2001-10-26 14:56:06 +0000568- Assignment to object.__dict__ is now possible, for objects that are
569 instances of new-style classes that have a __dict__ (unless the base
570 class forbids it).
571
Guido van Rossumc8e56452001-10-22 00:43:43 +0000572- Methods of built-in types now properly check for keyword arguments
573 (formerly these were silently ignored). The only built-in methods
574 that take keyword arguments are __call__, __init__ and __new__.
575
Guido van Rossum86443212001-10-27 22:28:54 +0000576- The socket function has been converted to a type; see below.
577
Tim Peters84362bc2001-10-19 17:55:30 +0000578Core and builtins
579
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000580- Assignment to __debug__ raises SyntaxError at compile-time. This
581 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000582 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000583
Guido van Rossum12d955c2001-10-26 14:56:06 +0000584- Clarified the error messages for unsupported operands to an operator
585 (like 1 + '').
586
Tim Peters84362bc2001-10-19 17:55:30 +0000587Extension modules
588
Tim Peters5ebfd362001-11-13 23:11:19 +0000589- mmap has a new keyword argument, "access", allowing a uniform way for
590 both Windows and Unix users to create read-only, write-through and
591 copy-on-write memory mappings. This was previously possible only on
592 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000593 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000594 platforms. Thanks to Jay T Miller for repairing this!
595
Tim Peters169ded02001-11-03 19:57:21 +0000596- By default, the gc.garbage list now contains only those instances in
597 unreachable cycles that have __del__ methods; in 2.1 it contained all
598 instances in unreachable cycles. "Instances" here has been generalized
599 to include instances of both new-style and old-style classes.
600
Guido van Rossum12d955c2001-10-26 14:56:06 +0000601- The socket module defines a new method for socket objects,
602 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000603 send() until all data has been sent. Also, the socket function has
604 been converted to a subclassable type, like list and tuple (etc.)
605 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000606
607- Various bugfixes to the curses module. There is now a test suite
608 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000609
Guido van Rossum692adf12001-10-30 03:03:03 +0000610- binascii.b2a_base64 no longer places an arbitrary restriction of 57
611 bytes on its input.
612
Tim Peters84362bc2001-10-19 17:55:30 +0000613Library
614
Tim Peters5ebfd362001-11-13 23:11:19 +0000615- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000616 convenience function.
617
Tim Peters75335872001-11-03 19:35:43 +0000618- Symbolic group names in regular expressions must be unique. For
619 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
620 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000621 Python 2.2 detects this error at regexp compilation time;
622 previously, the error went undetected, and results were
623 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
624 pattern.subn() methods have been rewritten in C. Also, an
625 experimental function/method finditer() has been added, which works
626 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000627
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000628- Tix exposes more commands through the classes DirSelectBox,
629 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
630 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
631 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
632
Tim Peters98791af2001-10-23 01:59:54 +0000633- Traceback objects are now scanned by cyclic garbage collection, so
634 cycles created by casual use of sys.exc_info() no longer cause
635 permanent memory leaks (provided garbage collection is enabled).
636
Guido van Rossum49192142001-10-24 20:51:44 +0000637- os.extsep -- a new variable needed by the RISCOS support. It is the
638 separator used by extensions, and is '.' on all platforms except
639 RISCOS, where it is '/'. There is no need to use this variable
640 unless you have a masochistic desire to port your code to RISCOS.
641
Barry Warsaw012852b2001-11-16 16:17:27 +0000642- mimetypes.py has optional support for non-standard, but commonly
643 found types. guess_type() and guess_extension() now accept an
644 optional `strict' flag, defaulting to true, which controls whether
645 recognize non-standard types or not. A few non-standard types we
646 know about have been added. Also, when run as a script, there are
647 new -l and -e options.
648
649- statcache is now deprecated.
650
651- email.Utils.formatdate() now produces the preferred RFC 2822 style
652 dates with numeric timezones (it used to produce obsolete dates
653 hard coded to "GMT" timezone). An optional `localtime' flag is
654 added to produce dates in the local timezone, with daylight savings
655 time properly taken into account.
656
657- In pickle and cPickle, instead of masking errors in load() by
658 transforming them into SystemError, we let the original exception
659 propagate out. Also, implement support for __safe_for_unpickling__
660 in pickle, as it already was supported in cPickle.
661
Tim Peters84362bc2001-10-19 17:55:30 +0000662Tools/Demos
663
664Build
665
Barry Warsaw012852b2001-11-16 16:17:27 +0000666- The dbm module is built using libdb1 if available. The bsddb module
667 is built with libdb3 if available.
668
669- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
670
Tim Peters84362bc2001-10-19 17:55:30 +0000671C API
672
Tim Peters1fc240e2001-10-26 05:06:50 +0000673- New function PySequence_Fast_GET_SIZE() returns the size of a non-
674 NULL result from PySequence_Fast(), more quickly than calling
675 PySequence_Size().
676
Barry Warsaw012852b2001-11-16 16:17:27 +0000677- New argument unpacking function PyArg_UnpackTuple() added.
678
679- New functions PyObject_CallFunctionObjArgs() and
680 PyObject_CallMethodObjArgs() have been added to make it more
681 convenient and efficient to call functions and methods from C.
682
683- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
684 possible that this will propagate errors it didn't before.
685
686- New function PyObject_CheckReadBuffer(), which returns true if its
687 argument supports the single-segment readable buffer interface.
688
Tim Peters84362bc2001-10-19 17:55:30 +0000689New platforms
690
Guido van Rossum86443212001-10-27 22:28:54 +0000691- We've finally confirmed that this release builds on HP-UX 11.00,
692 *with* threads, and passes the test suite.
693
Tim Peters7a33d8b2001-11-05 02:51:07 +0000694- Thanks to a series of patches from Michael Muller, Python may build
695 again under OS/2 Visual Age C++.
696
Guido van Rossum49192142001-10-24 20:51:44 +0000697- Updated RISCOS port by Dietmar Schwertberger.
698
Tim Peters84362bc2001-10-19 17:55:30 +0000699Tests
700
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000701- Added a test script for the curses module. It isn't run automatically;
702 regrtest.py must be run with '-u curses' to enable it.
703
Tim Peters84362bc2001-10-19 17:55:30 +0000704Windows
705
Barry Warsaw012852b2001-11-16 16:17:27 +0000706Mac
707
708- PythonScript has been moved to unsupported and is slated to be
709 removed completely in the next release.
710
711- It should now be possible to build applets that work on both OS9 and
712 OSX.
713
714- The core is now linked with CoreServices not Carbon; as a side
715 result, default 8bit encoding on OSX is now ASCII.
716
717- Python should now build on OSX 10.1.1
718
Tim Peters84362bc2001-10-19 17:55:30 +0000719
Tim Petersabf925f2001-09-28 21:53:42 +0000720What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000721Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000722===========================
723
724Type/class unification and new-style classes
725
Guido van Rossum687ae002001-10-15 22:03:32 +0000726- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000727 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000728 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000729 remains: the __dict__ of a new-style class is a read-only proxy; you
730 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000731 __defined__ attribute of new-style types no longer exists, for lack
732 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000733 future a __cache__ may be resurrected with a similar function, if I
734 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000735
Tim Peters1c9ca872001-10-04 06:43:12 +0000736- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
737 always returned None, even when there was a class docstring).
738
739- doctest now finds and runs docstrings attached to new-style classes,
740 class methods, static methods, and properties.
741
Guido van Rossum9074ef62001-10-16 21:34:49 +0000742Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000743
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000744- A very subtle syntactical pitfall in list comprehensions was fixed.
745 For example: [a+b for a in 'abc', for b in 'def']. The comma in
746 this example is a mistake. Previously, this would silently let 'a'
747 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
748 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
749 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
750 Note that [a for a in <singleton>] is a convoluted way to say
751 [<singleton>] anyway, so it's not like any expressiveness is lost.
752
Guido van Rossum9074ef62001-10-16 21:34:49 +0000753- getattr(obj, name, default) now only catches AttributeError, as
754 documented, rather than returning the default value for all
755 exceptions (which could mask bugs in a __getattr__ hook, for
756 example).
757
Fred Drakecb7a6b52001-10-22 18:41:51 +0000758- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000759 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000760 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000761 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000762
Guido van Rossum1c486092001-10-19 02:05:35 +0000763- unicode(obj) now behaves more like str(obj), accepting arbitrary
764 objects, and calling a __unicode__ method if it exists.
765 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000766 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000767
Barry Warsawf6fb1712001-10-19 05:35:40 +0000768- isinstance() now allows any object as the first argument and a
769 class, a type or something with a __bases__ tuple attribute for the
770 second argument. The second argument may also be a tuple of a
771 class, type, or something with __bases__, in which case isinstance()
772 will return true if the first argument is an instance of any of the
773 things contained in the second argument tuple. E.g.
774
775 isinstance(x, (A, B))
776
777 returns true if x is an instance of A or B.
778
Guido van Rossum9074ef62001-10-16 21:34:49 +0000779Extension modules
780
781- thread.start_new_thread() now returns the thread ID (previously None).
782
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000783- binascii has now two quopri support functions, a2b_qp and b2a_qp.
784
Guido van Rossumc524d952001-10-19 01:31:59 +0000785- readline now supports setting the startup_hook and the
786 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000787
Guido van Rossumc524d952001-10-19 01:31:59 +0000788- os and posix supports chroot(), setgroups() and unsetenv() where
789 available. The stat(), fstat(), statvfs() and fstatvfs() functions
790 now return "pseudo-sequences" -- the various fields can now be
791 accessed as attributes (e.g. os.stat("/").st_mtime) but for
792 backwards compatibility they also behave as a fixed-length sequence.
793 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000794 attributes.
795
796- time: localtime(), gmtime() and strptime() now return a
797 pseudo-sequence similar to the os.stat() return value, with
798 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000799
Guido van Rossum9074ef62001-10-16 21:34:49 +0000800- Decompression objects in the zlib module now accept an optional
801 second parameter to decompress() that specifies the maximum amount
802 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000803
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000804- optional SSL support in the socket module now exports OpenSSL
805 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
806 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000807 automatically seed its PRNG. Also, the keyfile and certfile
808 arguments to socket.ssl() are now optional.
809
810- posixmodule (and by extension, the os module on POSIX platforms) now
811 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000812
Guido van Rossum9074ef62001-10-16 21:34:49 +0000813Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000814
Tim Peters7402f792001-10-02 03:53:41 +0000815- doctest now excludes functions and classes not defined by the module
816 being tested, thanks to Tim Hochberg.
817
Fred Drakecb7a6b52001-10-22 18:41:51 +0000818- HotShot, a new profiler implemented using a C-based callback, has
819 been added. This substantially reduces the overhead of profiling,
820 but it is still quite preliminary. Support modules and
821 documentation will be added in upcoming releases (before 2.2 final).
822
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000823- profile now produces correct output in situations where an exception
824 raised in Python is cleared by C code (e.g. hasattr()). This used
825 to cause wrong output, including spurious claims of recursive
826 functions and attribution of time spent to the wrong function.
827
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000828 The code and documentation for the derived OldProfile and HotProfile
829 profiling classes was removed. The code hasn't worked for years (if
830 you tried to use them, they raised exceptions). OldProfile
831 intended to reproduce the behavior of the profiler Python used more
832 than 7 years ago, and isn't interesting anymore. HotProfile intended
833 to provide a faster profiler (but producing less information), and
834 that's a worthy goal we intend to meet via a different approach (but
835 without losing information).
836
Tim Peterscce092d2001-10-09 05:31:56 +0000837- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000838 a much better system-specific calibration constant. The constant can
839 now be specified in an instance constructor, or as a Profile class or
840 instance variable, instead of by editing profile.py's source code.
841 Calibration must still be done manually (see the docs for the profile
842 module).
843
844 Note that Profile.calibrate() must be overriden by subclasses.
845 Improving the accuracy required exploiting detailed knowledge of
846 profiler internals; the earlier method abstracted away the details
847 and measured a simplified model instead, but consequently computed
848 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000849
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000850- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000851 which indicates whether output is intended for the header 'Q'
852 encoding.
853
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000854- The SocketServer.ThreadingMixIn class now closes the request after
855 finish_request() returns. (Not when it errors out though.)
856
Barry Warsawf6fb1712001-10-19 05:35:40 +0000857- The nntplib module's NNTP.body() method has grown a `file' argument
858 to allow saving the message body to a file.
859
860- The email package has added a class email.Parser.HeaderParser which
861 only parses headers and does not recurse into the message's body.
862 Also, the module/class MIMEAudio has been added for representing
863 audio data (contributed by Anthony Baxter).
864
865- ftplib should be able to handle files > 2GB.
866
867- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
868 ON, and OFF.
869
Fred Drakecb7a6b52001-10-22 18:41:51 +0000870- xml.dom.minidom NodeList objects now support the length attribute
871 and item() method as required by the DOM specifications.
872
Guido van Rossumed554f62001-10-02 23:15:37 +0000873Tools/Demos
874
875- Demo/dns was removed. It no longer serves any purpose; a package
876 derived from it is now maintained by Anthony Baxter, see
877 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000878
Barry Warsawf6fb1712001-10-19 05:35:40 +0000879- The freeze tool has been made more robust, and two new options have
880 been added: -X and -E.
881
Tim Petersabf925f2001-09-28 21:53:42 +0000882Build
883
Barry Warsawf6fb1712001-10-19 05:35:40 +0000884- configure will use CXX in LINKCC if CXX is used to build main() and
885 the system requires to link a C++ main using the C++ compiler.
886
Tim Petersabf925f2001-09-28 21:53:42 +0000887C API
888
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000889- The documentation for the tp_compare slot is updated to require that
890 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
891 not correct. This is not yet enforced but will be enforced in
892 Python 2.3; even later, we may use -2 to indicate errors and +2 for
893 "NotImplemented". Right now, -1 should be used for an error return.
894
Tim Petersd38b1c72001-09-30 05:09:37 +0000895- PyLong_AsLongLong() now accepts int (as well as long) arguments.
896 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
897 as long) arguments.
898
Guido van Rossum3c288632001-10-16 21:13:49 +0000899- PyThread_start_new_thread() now returns a long int giving the thread
900 ID, if one can be calculated; it returns -1 for error, 0 if no
901 thread ID is calculated (this is an incompatible change, but only
902 the thread module used this API). This code has only really been
903 tested on Linux and Windows; other platforms please beware (and
904 report any bugs or strange behavior).
905
Guido van Rossum1c486092001-10-19 02:05:35 +0000906- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
907 input.
908
Tim Petersabf925f2001-09-28 21:53:42 +0000909New platforms
910
911Tests
912
913Windows
914
Tim Peters04cf1d32001-10-09 22:39:40 +0000915- Installer: If you install IDLE, and don't disable file-extension
916 registration, a new "Edit with IDLE" context (right-click) menu entry
917 is created for .py and .pyw files.
918
Tim Peters1ce3cf72001-10-01 17:58:40 +0000919- The signal module now supports SIGBREAK on Windows, thanks to Steven
920 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
921 action remains to call Win32 ExitProcess(). This can be changed via
922 signal.signal(). For example:
923
924 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
925 # (SIGINT) behavior.
926 import signal
927 signal.signal(signal.SIGBREAK,
928 signal.default_int_handler)
929
930 try:
931 while 1:
932 pass
933 except KeyboardInterrupt:
934 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
935 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
936 # program without the possibility for any Python-level cleanup).
937 print "Clean exit"
938
Tim Petersabf925f2001-09-28 21:53:42 +0000939
Tim Petersb07352e2001-09-08 01:25:47 +0000940What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000941Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000942===========================
943
Guido van Rossum808eea72001-09-25 04:15:41 +0000944Type/class unification and new-style classes
945
946- pydoc and inspect are now aware of new-style classes;
947 e.g. help(list) at the interactive prompt now shows proper
948 documentation for all operations on list objects.
949
950- Applications using Jim Fulton's ExtensionClass module can now safely
951 be used with Python 2.2. In particular, Zope 2.4.1 now works with
952 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
953 examples also work again. It is hoped that Gtk and Boost also work
954 with 2.2a4 and beyond. (If you can confirm this, please write
955 webmaster@python.org; if there are still problems, please open a bug
956 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000957
Tim Peters66c1a522001-09-24 21:17:50 +0000958- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000959 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +0000960 in the constructed property object. fget, fset and fdel weren't
961 discoverable from Python in 2.2a3. __doc__ is new, and allows to
962 associate a docstring with a property.
963
Guido van Rossum808eea72001-09-25 04:15:41 +0000964- Comparison overloading is now more completely implemented. For
965 example, a str subclass instance can properly be compared to a str
966 instance, and it can properly overload comparison. Ditto for most
967 other built-in object types.
968
969- The repr() of new-style classes has changed; instead of <type
970 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
971 *except* for built-in types, which are still rendered as <type
972 'Foo'> (to avoid upsetting existing code that might parse or
973 otherwise rely on repr() of certain type objects).
974
975- The repr() of new-style objects is now always <Foo object at XXX>;
976 previously, it was sometimes <Foo instance at XXX>.
977
978- For new-style classes, what was previously called __getattr__ is now
979 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000980 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000981 one in classic classes is defined which is called only if regular
982 attribute access raises AttributeError; to catch *all* attribute
983 access, you can use __getattribute__ (for new-style classes). If
984 both are defined, __getattribute__ is called first, and if it raises
985 AttributeError, __getattr__ is called.
986
987- The __class__ attribute of new-style objects can be assigned to.
988 The new class must have the same C-level object layout as the old
989 class.
990
991- The builtin file type can be subclassed now. In the usual pattern,
992 "file" is the name of the builtin type, and file() is a new builtin
993 constructor, with the same signature as the builtin open() function.
994 file() is now the preferred way to open a file.
995
996- Previously, __new__ would only see sequential arguments passed to
997 the type in a constructor call; __init__ would see both sequential
998 and keyword arguments. This made no sense whatsoever any more, so
999 now both __new__ and __init__ see all arguments.
1000
1001- Previously, hash() applied to an instance of a subclass of str or
1002 unicode always returned 0. This has been repaired.
1003
1004- Previously, an operation on an instance of a subclass of an
1005 immutable type (int, long, float, complex, tuple, str, unicode),
1006 where the subtype didn't override the operation (and so the
1007 operation was handled by the builtin type), could return that
1008 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001009 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001010 with the same value as s.
1011
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001012- Provisional support for pickling new-style objects has been added.
1013
Guido van Rossum808eea72001-09-25 04:15:41 +00001014Core
1015
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001016- file.writelines() now accepts any iterable object producing strings.
1017
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001018- PyUnicode_FromEncodedObject() now works very much like
1019 PyObject_Str(obj) in that it tries to use __str__/tp_str
1020 on the object if the object is not a string or buffer. This
1021 makes unicode() behave like str() when applied to non-string/buffer
1022 objects.
1023
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001024- PyFile_WriteObject now passes Unicode objects to the file's write
1025 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001026 of a print statement must support Unicode objects, i.e. they must
1027 at least convert them into ASCII strings.
1028
Guido van Rossum624c8af2001-09-18 15:21:04 +00001029- Thread scheduling on Solaris should be improved; it is no longer
1030 necessary to insert a small sleep at the start of a thread in order
1031 to let other runnable threads be scheduled.
1032
Tim Petersb07352e2001-09-08 01:25:47 +00001033Library
1034
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001035- StringIO.StringIO instances and cStringIO.StringIO instances support
1036 read character buffer compatible objects for their .write() methods.
1037 These objects are converted to strings and then handled as such
1038 by the instances.
1039
Barry Warsaw2f600732001-09-24 04:28:10 +00001040- The "email" package has been added. This is basically a port of the
1041 mimelib package <http://sf.net/projects/mimelib> with API changes
1042 and some implementations updated to use iterators and generators.
1043
Tim Peters8a9c2842001-09-22 21:30:22 +00001044- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1045 restores the ability of Tools/scripts/ndiff.py to start producing output
1046 before the entire comparison is complete.
1047
Barry Warsaw58b072d2001-09-22 04:44:21 +00001048- StringIO.StringIO instances and cStringIO.StringIO instances support
1049 iteration just like file objects (i.e. their .readline() method is
1050 called for each iteration until it returns an empty string).
1051
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001052- The codecs module has grown four new helper APIs to access
1053 builtin codecs: getencoder(), getdecoder(), getreader(),
1054 getwriter().
1055
Guido van Rossum624c8af2001-09-18 15:21:04 +00001056- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1057 simplifies writing XML RPC servers.
1058
Barry Warsaw647d5e82001-09-28 17:01:02 +00001059- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001060 after interpretation of symbolic links. On non-Unix systems, this
1061 is an alias for os.path.abspath().
1062
Tim Peters16a77ad2001-09-08 04:00:12 +00001063- operator.indexOf() (PySequence_Index() in the C API) now works with any
1064 iterable object.
1065
Guido van Rossum624c8af2001-09-18 15:21:04 +00001066- smtplib now supports various authentication and security features of
1067 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001068
Guido van Rossum624c8af2001-09-18 15:21:04 +00001069- hmac: a new module implementing keyed hashing for message
1070 authentication.
1071
1072- mimetypes now recognizes more extensions and file types. At the
1073 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001074
Guido van Rossum624c8af2001-09-18 15:21:04 +00001075- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001076 Python 2.2 bytecode generation. It has also been promoted from a
1077 Tool to a standard library package. (Tools/compiler still exists as
1078 a sample driver.)
1079
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001080Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001081
Tim Petersb07352e2001-09-08 01:25:47 +00001082Build
1083
Guido van Rossum624c8af2001-09-18 15:21:04 +00001084- Large file support (LFS) is now automatic when the platform supports
1085 it; no more manual configuration tweaks are needed. On Linux, at
1086 least, it's possible to have a system whose C library supports large
1087 files but whose kernel doesn't; in this case, large file support is
1088 still enabled but doesn't do you any good unless you upgrade your
1089 kernel or share your Python executable with another system whose
1090 kernel has large file support.
1091
1092- The configure script now supplies plausible defaults in a
1093 cross-compilation environment. This doesn't mean that the supplied
1094 values are always correct, or that cross-compilation now works
1095 flawlessly -- but it's a first step (and it shuts up most of
1096 autoconf's warnings about AC_TRY_RUN).
1097
1098- The Unix build is now a bit less chatty, courtesy of the parser
1099 generator. The build is completely silent (except for errors) when
1100 using "make -s", thanks to a -q option to setup.py.
1101
Tim Petersb07352e2001-09-08 01:25:47 +00001102C API
1103
Guido van Rossum624c8af2001-09-18 15:21:04 +00001104- The "structmember" API now supports some new flag bits to deny read
1105 and/or write access to attributes in restricted execution mode.
1106
Tim Petersb07352e2001-09-08 01:25:47 +00001107New platforms
1108
Guido van Rossum624c8af2001-09-18 15:21:04 +00001109- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1110 (http://familiar.handhelds.org).
1111
Tim Petersb07352e2001-09-08 01:25:47 +00001112Tests
1113
Tim Peters8a9c2842001-09-22 21:30:22 +00001114- The "classic" standard tests, which work by comparing stdout to
1115 an expected-output file under Lib/test/output/, no longer stop at
1116 the first mismatch. Instead the test is run to completion, and a
1117 variant of ndiff-style comparison is used to report all differences.
1118 This is much easier to understand than the previous style of reporting.
1119
1120- The unittest-based standard tests now use regrtest's test_main()
1121 convention, instead of running as a side-effect of merely being
1122 imported. This allows these tests to be run in more natural and
1123 flexible ways as unittests, outside the regrtest framework.
1124
1125- regrtest.py is much better integrated with unittest and doctest now,
1126 especially in regard to reporting errors.
1127
Tim Petersb07352e2001-09-08 01:25:47 +00001128Windows
1129
Guido van Rossum624c8af2001-09-18 15:21:04 +00001130- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001131 that support it (NTFS under Windows 2000). See "What's New in
1132 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001133
Tim Petersb07352e2001-09-08 01:25:47 +00001134
Tim Petersedc99312001-08-22 21:36:50 +00001135What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001136Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001137===========================
1138
1139Core
1140
Tim Peters9fffa3e2001-09-04 05:14:19 +00001141- Conversion of long to float now raises OverflowError if the long is too
1142 big to represent as a C double.
1143
Tim Peters32f453e2001-09-03 08:35:41 +00001144- The 3-argument builtin pow() no longer allows a third non-None argument
1145 if either of the first two arguments is a float, or if both are of
1146 integer types and the second argument is negative (in which latter case
1147 the arguments are converted to float, so this is really the same
1148 restriction).
1149
Tim Peters5d2b77c2001-09-03 05:47:38 +00001150- The builtin dir() now returns more information, and sometimes much
1151 more, generally naming all attributes of an object, and all attributes
1152 reachable from the object via its class, and from its class's base
1153 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1154 an empty list. In 2.2a3,
1155
1156 >>> dir([])
1157 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1158 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1159 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1160 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1161 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1162 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1163 'reverse', 'sort']
1164
1165 dir(module) continues to return only the module's attributes, though.
1166
Tim Petersbdee63f2001-09-02 03:40:59 +00001167- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001168 than raising OverflowError. This is a partial implementation of PEP
1169 237. You can use -Wdefault::OverflowWarning to enable a warning for
1170 this situation, and -Werror::OverflowWarning to revert to the old
1171 OverflowError exception.
1172
Guido van Rossum61c345f2001-09-04 03:26:15 +00001173- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001174 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001175 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1176 -Qold, meaning the / operator has its classic meaning and no
1177 warnings are issued. Using -Qwarn issues a run-time warning about
1178 all uses of classic division for int and long arguments; -Qwarnall
1179 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001180 (for use with fixdiv.py).
1181 [Note: the remainder of this paragraph (preserved below) became
1182 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1183 <obsolete>
1184 Using -Qnew is questionable; it turns on new division by default, but
1185 only in the __main__ module. You can usefully combine -Qwarn or
1186 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1187 warns about classic division everywhere else.
1188 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001189
Tim Petersbdee63f2001-09-02 03:40:59 +00001190- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001191 long, float, str, unicode, and tuple. (The types complex, list and
1192 dictionary can also be subclassed; this was introduced earlier.)
1193 Note that restrictions apply when subclassing immutable built-in
1194 types: you can only affect the value of the instance by overloading
1195 __new__. You can add mutable attributes, and the subclass instances
1196 will have a __dict__ attribute, but you cannot change the "value"
1197 (as implemented by the base class) of an immutable subclass instance
1198 once it is created.
1199
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001200- The dictionary constructor now takes an optional argument, a
1201 mapping-like object, and initializes the dictionary from its
1202 (key, value) pairs.
1203
Tim Petersbdee63f2001-09-02 03:40:59 +00001204- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001205 "cooperative super calls" in a multiple inheritance setting. For an
1206 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1207
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001208- A new built-in type, property, has been added. This enables the
1209 creation of "properties". These are attributes implemented by
1210 getter and setter functions (or only one of these for read-only or
1211 write-only attributes), without the need to override __getattr__.
1212 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001213
Tim Petersbdee63f2001-09-02 03:40:59 +00001214- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001215 liberalized, to allow leading zeroes. Examples of literals now
1216 legal that were SyntaxErrors before:
1217
1218 00.0 0e3 0100j 07.5 00000000000000000008.
1219
Tim Petersbdee63f2001-09-02 03:40:59 +00001220- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001221 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1222
Tim Petersedc99312001-08-22 21:36:50 +00001223Library
1224
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001225- telnetlib includes symbolic names for the options, and support for
1226 setting an option negotiation callback.
1227
Tim Petersa40c7932001-09-05 22:36:56 +00001228- The new C standard no longer requires that math libraries set errno to
1229 ERANGE on overflow. For platform libraries that exploit this new
1230 freedom, Python's overflow-checking was wholly broken. A new overflow-
1231 checking scheme attempts to repair that, but may not be reliable on all
1232 platforms (C doesn't seem to provide anything both useful and portable
1233 in this area anymore).
1234
Martin v. Löwis44f86962001-09-05 13:44:54 +00001235- Asynchronous timeout actions are available through the new class
1236 threading.Timer.
1237
Tim Peters78526162001-09-05 00:53:45 +00001238- math.log and math.log10 now return sensible results for even huge
1239 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1240
Tim Petersbdee63f2001-09-02 03:40:59 +00001241- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001242 currently held. See the docs for the imp module.
1243
Tim Petersbdee63f2001-09-02 03:40:59 +00001244- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001245 dumps containing ints written on platforms where Python ints are 8 bytes.
1246 When read on a box where Python ints are 4 bytes, such values are
1247 converted to Python longs.
1248
Tim Petersbdee63f2001-09-02 03:40:59 +00001249- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001250 code objects is no longer allowed. This plugs a security hole.
1251
Steve Purcell6091cd62001-09-06 16:05:17 +00001252- unittest.TestResult instances no longer store references to tracebacks
1253 generated by test failures. This prevents unexpected dangling references
1254 to objects that should be garbage collected between tests.
1255
Tim Petersedc99312001-08-22 21:36:50 +00001256Tools
1257
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001258- Tools/scripts/fixdiv.py has been added which can be used to fix
1259 division operators as per PEP 238.
1260
Tim Petersedc99312001-08-22 21:36:50 +00001261Build
1262
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001263- If you are an adventurous person using Mac OS X you may want to look at
1264 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1265 application, which can be used for experimenting with Carbon or Cocoa.
1266 Discussion of this on pythonmac-sig, please.
1267
Tim Peters7eea37e2001-09-04 22:08:56 +00001268C API
1269
1270- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001271
Tim Peters9fffa3e2001-09-04 05:14:19 +00001272- Note that PyLong_AsDouble can fail! This has always been true, but no
1273 callers checked for it. It's more likely to fail now, because overflow
1274 errors are properly detected now. The proper way to check:
1275
1276 double x = PyLong_AsDouble(some_long_object);
1277 if (x == -1.0 && PyErr_Occurred()) {
1278 /* The conversion failed. */
1279 }
1280
Tim Petersbdee63f2001-09-02 03:40:59 +00001281- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001282 compile but will not participate in GC. To upgrade an extension
1283 module:
1284
1285 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001286
Neil Schemenauer4042c692001-08-30 15:38:01 +00001287 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1288 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001289
Neil Schemenauer4042c692001-08-30 15:38:01 +00001290 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1291 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001292
Neil Schemenauer4042c692001-08-30 15:38:01 +00001293 - remove PyGC_HEAD_SIZE from object size calculations
1294
1295 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1296
Tim Petersbdee63f2001-09-02 03:40:59 +00001297- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001298 These can be used safely to construct string objects from a
1299 sprintf-style format string (similar to the format string supported
1300 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001301
Tim Petersedc99312001-08-22 21:36:50 +00001302New platforms
1303
Tim Petersb7da0902001-09-02 23:01:43 +00001304- Stephen Hansen contributed patches sufficient to get a clean compile
1305 under Borland C (Windows), but he reports problems running it and ran
1306 out of time to complete the port. Volunteers? Expect a MemoryError
1307 when importing the types module; this is probably shallow, and
1308 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001309
Tim Petersedc99312001-08-22 21:36:50 +00001310Tests
1311
1312Windows
1313
Tim Peters6e13a562001-09-06 00:32:15 +00001314- Large file support is now enabled on Win32 platforms as well as on
1315 Win64. This means that, for example, you can use f.tell() and f.seek()
1316 to manipulate files larger than 2 gigabytes (provided you have enough
1317 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001318 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1319 filesize limit, and large file support makes no difference there.
1320 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1321 NTFS has no practical limit on file size, and files of any size can be
1322 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001323
Tim Petersbdee63f2001-09-02 03:40:59 +00001324- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001325 points to command.com (patch from Brian Quinlan).
1326
Tim Petersedc99312001-08-22 21:36:50 +00001327
Tim Peters20f51a72001-07-21 02:31:40 +00001328What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001329Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001330===========================
1331
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001332Build
1333
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001334- Tim Peters developed a brand new Windows installer using Wise 8.1,
1335 generously donated to us by Wise Solutions.
1336
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001337- configure supports a new option --enable-unicode, with the values
1338 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1339 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001340
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001341- A new configure option --enable-framework builds a Mac OS X framework,
1342 which "make frameworkinstall" will install. This provides a starting
1343 point for more mac-like functionality, join pythonmac-sig@python.org
1344 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001345
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001346- The NeXT platform is no longer supported.
1347
1348- The `new' module is now statically linked.
1349
Tim Peters0afb6092001-08-15 06:06:44 +00001350Tools
1351
1352- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001353 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001354 the module docstring for details.
1355
Tim Peters20f51a72001-07-21 02:31:40 +00001356Tests
1357
Tim Peters5e824c32001-08-12 22:25:01 +00001358- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001359 platforms, allowing to give clearer test result output. regrtest
1360 also has optional --use/-u switch to run normally disabled tests
1361 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001362
Tim Peters20f51a72001-07-21 02:31:40 +00001363- Several new tests in the standard test suite, with special thanks to
1364 Nick Mathewson.
1365
1366Core
1367
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001368- The floor division operator // has been added as outlined in PEP
1369 238. The / operator still provides classic division (and will until
1370 Python 3.0) unless "from __future__ import division" is included, in
1371 which case the / operator will provide true division. The operator
1372 module provides truediv() and floordiv() functions. Augmented
1373 assignment variants are included, as are the equivalent overloadable
1374 methods and C API methods. See the PEP for a full discussion:
1375 <http://python.sf.net/peps/pep-0238.html>
1376
Tim Peters6cd6a822001-08-17 22:11:27 +00001377- Future statements are now effective in simulated interactive shells
1378 (like IDLE). This should "just work" by magic, but read Michael
1379 Hudson's "Future statements in simulated shells" PEP 264 for full
1380 details: <http://python.sf.net/peps/pep-0264.html>.
1381
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001382- The type/class unification (PEP 252-253) was integrated into the
1383 trunk and is not so tentative any more (the exact specification of
1384 some features is still tentative). A lot of work has done on fixing
1385 bugs and adding robustness and features (performance still has to
1386 come a long way).
1387
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001388- Warnings about a mismatch in the Python API during extension import
1389 now use the Python warning framework (which makes it possible to
1390 write filters for these warnings).
1391
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001392- A function's __dict__ (aka func_dict) will now always be a
1393 dictionary. It used to be possible to delete it or set it to None,
1394 but now both actions raise TypeErrors. It is still legal to set it
1395 to a dictionary object. Getting func.__dict__ before any attributes
1396 have been assigned now returns an empty dictionary instead of None.
1397
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001398- A new command line option, -E, was added which disables the use of
1399 all environment variables, or at least those that are specifically
1400 significant to Python. Usually those have a name starting with
1401 "PYTHON". This was used to fix a problem where the tests fail if
1402 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1403 older distribution.
1404
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001405Library
1406
Tim Peters5e824c32001-08-12 22:25:01 +00001407- New class Differ and new functions ndiff() and restore() in difflib.py.
1408 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001409 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001410
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001411- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1412 value using the minimal quoting required for the value; more
1413 reliable than using xml.sax.saxutils.escape() for attribute values.
1414
1415- Readline completion support for cmd.Cmd was added.
1416
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001417- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1418
1419- Added function threading.BoundedSemaphore()
1420
1421- Added Ka-Ping Yee's cgitb.py module.
1422
1423- The `new' module now exposes the CO_xxx flags.
1424
Martin v. Löwis560da622001-11-24 09:24:51 +00001425- The gc module offers the get_referents function.
1426
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001427New platforms
1428
1429C API
1430
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001431- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1432 which provide a cross-platform implementations for the
1433 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1434 the standard sprintf() and vsprintf() C lib APIs, these versions
1435 apply bounds checking on the used buffer which enhances protection
1436 against buffer overruns.
1437
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001438- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001439 and extensions using different Unicode widths is rendered next to
1440 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001441 will result in an ImportError. Unicode extensions writers must make
1442 sure to check the Unicode width compatibility in their extensions by
1443 using at least one of the mangled Unicode APIs in the extension.
1444
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001445- Two new flags METH_NOARGS and METH_O are available in method definition
1446 tables to simplify implementation of methods with no arguments and a
1447 single untyped argument. Calling such methods is more efficient than
1448 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1449 deprecated.
1450
Tim Petersc1731372001-08-04 08:12:36 +00001451Windows
1452
1453- "import module" now compiles module.pyw if it exists and nothing else
1454 relevant is found.
1455
Tim Peters20f51a72001-07-21 02:31:40 +00001456
Guido van Rossum55a78992001-07-17 17:22:32 +00001457What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001458Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001459===========================
1460
1461Core
Tim Petersa814db52001-05-14 07:05:58 +00001462
Tim Peters6d6c1a32001-08-02 04:15:00 +00001463- TENTATIVELY, a large amount of code implementing much of what's
1464 described in PEP 252 (Making Types Look More Like Classes) and PEP
1465 253 (Subtyping Built-in Types) was added. This will be released
1466 with Python 2.2a1. Documentation will be provided separately
1467 through http://www.python.org/2.2/. The purpose of releasing this
1468 with Python 2.2a1 is to test backwards compatibility. It is
1469 possible, though not likely, that a decision is made not to release
1470 this code as part of 2.2 final, if any serious backwards
1471 incompapatibilities are found during alpha testing that cannot be
1472 repaired.
1473
Guido van Rossum55a78992001-07-17 17:22:32 +00001474- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001475 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001476 more 'yield' statements. See PEP 255. Since this adds a new
1477 keyword to the language, this feature must be enabled by including a
1478 future statement: "from __future__ import generators" (see PEP 236).
1479 Generators will become a standard feature in a future release
1480 (probably 2.3). Without this future statement, 'yield' remains an
1481 ordinary identifier, but a warning is issued each time it is used.
1482 (These warnings currently don't conform to the warnings framework of
1483 PEP 230; we intend to fix this in 2.2a2.)
1484
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001485- The UTF-16 codec was modified to be more RFC compliant. It will now
1486 only remove BOM characters at the start of the string and then
1487 only if running in native mode (UTF-16-LE and -BE won't remove a
1488 leading BMO character).
1489
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001490- Strings now have a new method .decode() to complement the already
1491 existing .encode() method. These two methods provide direct access
1492 to the corresponding decoders and encoders of the registered codecs.
1493
1494 To enhance the usability of the .encode() method, the special
1495 casing of Unicode object return values was dropped (Unicode objects
1496 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001497
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001498 Both methods will now return whatever the codec in charge of the
1499 requested encoding returns as object, e.g. Unicode codecs will
1500 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1501 will return u"äöü"). This enables codec writer to create codecs
1502 for various simple to use conversions.
1503
1504 New codecs were added to demonstrate these new features (the .encode()
1505 and .decode() columns indicate the type of the returned objects):
1506
1507 Name | .encode() | .decode() | Description
1508 ----------------------------------------------------------------------
1509 uu | string | string | UU codec (e.g. for email)
1510 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001511 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001512 zlib | string | string | zlib compression
1513 hex | string | string | 2-byte hex codec
1514 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1515
Mark Hammond2a0af792001-05-14 03:09:36 +00001516- Some operating systems now support the concept of a default Unicode
1517 encoding for file system operations. Notably, Windows supports 'mbcs'
1518 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001519 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001520 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001521
1522 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001523 functions that return filenames (such as os.listdir()) to return Python
1524 string objects pre-encoded using the default file system encoding for
1525 the platform. As this encoding is likely to be different from Python's
1526 default encoding, converting this name to a Unicode object before passing
1527 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001528 would attempt to use its default encoding (generally ASCII) rather than
1529 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001530
Tim Petersa814db52001-05-14 07:05:58 +00001531 In general, this change simply removes surprises when working with
1532 Unicode and the file system, making these operations work as you expect,
1533 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001534 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001535
Tim Peters61dff2b2001-05-08 15:43:37 +00001536- Float (and complex) literals in source code were evaluated to full
1537 precision only when running from a .py file; the same code loaded from a
1538 .pyc (or .pyo) file could suffer numeric differences starting at about the
1539 12th significant decimal digit. For example, on a machine with IEEE-754
1540 floating arithmetic,
1541
1542 x = 9007199254740992.0
1543 print long(x)
1544
1545 printed 9007199254740992 if run directly from .py, but 9007199254740000
1546 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1547 str(float) instead of repr(float) when building code objects. marshal
1548 now uses repr(float) instead, which should reproduce floats to full
1549 machine precision (assuming the platform C float<->string I/O conversion
1550 functions are of good quality).
1551
1552 This may cause floating-point results to change in some cases, and
1553 usually for the better, but may also cause numerically unstable
1554 algorithms to break.
1555
Tim Peters2f228e72001-05-13 00:19:31 +00001556- The implementation of dicts suffers fewer collisions, which has speed
1557 benefits. However, the order in which dict entries appear in dict.keys(),
1558 dict.values() and dict.items() may differ from previous releases for a
1559 given dict. Nothing is defined about this order, so no program should
1560 rely on it. Nevertheless, it's easy to write test cases that rely on the
1561 order by accident, typically because of printing the str() or repr() of a
1562 dict to an "expected results" file. See Lib/test/test_support.py's new
1563 sortdict(dict) function for a simple way to display a dict in sorted
1564 order.
1565
Tim Peters7a3bfc32001-06-12 01:22:22 +00001566- Many other small changes to dicts were made, resulting in faster
1567 operation along the most common code paths.
1568
Guido van Rossum10315822001-05-01 20:54:30 +00001569- Dictionary objects now support the "in" operator: "x in dict" means
1570 the same as dict.has_key(x).
1571
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001572- The update() method of dictionaries now accepts generic mapping
1573 objects. Specifically the argument object must support the .keys()
1574 and __getitem__() methods. This allows you to say, for example,
1575 {}.update(UserDict())
1576
Guido van Rossum10315822001-05-01 20:54:30 +00001577- Iterators were added; this is a generalized way of providing values
1578 to a for loop. See PEP 234. There's a new built-in function iter()
1579 to return an iterator. There's a new protocol to get the next value
1580 from an iterator using the next() method (in Python) or the
1581 tp_iternext slot (in C). There's a new protocol to get iterators
1582 using the __iter__() method (in Python) or the tp_iter slot (in C).
1583 Iterating (i.e. a for loop) over a dictionary generates its keys.
1584 Iterating over a file generates its lines.
1585
Tim Petersf553f892001-05-01 20:45:31 +00001586- The following functions were generalized to work nicely with iterator
1587 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001588 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001589 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1590 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001591 join() method of strings
1592 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001593 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1594 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001595 right-hand side of assignment statements with multiple targets, such as
1596 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001597
Tim Petersd85e1022001-05-11 21:51:48 +00001598- Accessing module attributes is significantly faster (for example,
1599 random.random or os.path or yourPythonModule.yourAttribute).
1600
Tim Peterse63415e2001-05-08 04:38:29 +00001601- Comparing dictionary objects via == and != is faster, and now works even
1602 if the keys and values don't support comparisons other than ==.
1603
Tim Peters95bf9392001-05-10 08:32:44 +00001604- Comparing dictionaries in ways other than == and != is slower: there were
1605 insecurities in the dict comparison implementation that could cause Python
1606 to crash if the element comparison routines for the dict keys and/or
1607 values mutated the dicts. Making the code bulletproof slowed it down.
1608
Tim Peterseb28ef22001-06-02 05:27:19 +00001609- Collisions in dicts are resolved via a new approach, which can help
1610 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001611 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001612 faster now. Thanks to Christian Tismer for pointing out the cause and
1613 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001614
Tim Peters52e155e2001-06-16 05:42:57 +00001615- repr() is much faster for large containers (dict, list, tuple).
1616
1617
Tim Petersa814db52001-05-14 07:05:58 +00001618Library
1619
Fred Drake960fdf92001-07-20 18:38:26 +00001620- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1621 were added to the string module. These a locale-indenpendent
1622 constants, unlike letters, lowercase, and uppercase. These are now
1623 use in appropriate locations in the standard library.
1624
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001625- The flags used in dlopen calls can now be configured using
1626 sys.setdlopenflags and queried using sys.getdlopenflags.
1627
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001628- Fredrik Lundh's xmlrpclib is now a standard library module. This
1629 provides full client-side XML-RPC support. In addition,
1630 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1631 one asyncore-based). Thanks to Eric Raymond for the documentation.
1632
Guido van Rossum643d3912001-07-05 14:46:25 +00001633- The xrange() object is simplified: it no longer supports slicing,
1634 repetition, comparisons, efficient 'in' checking, the tolist()
1635 method, or the start, stop and step attributes. See PEP 260.
1636
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001637- A new function fnmatch.filter to filter lists of file names was added.
1638
Barry Warsawffd674d2001-05-22 16:00:10 +00001639- calendar.py uses month and day names based on the current locale.
1640
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001641- strop is now *really* obsolete (this was announced before with 1.6),
1642 and issues DeprecationWarning when used (except for the four items
1643 that are still imported into string.py).
1644
Tim Petersa814db52001-05-14 07:05:58 +00001645- Cookie.py now sorts key+value pairs by key in output strings.
1646
1647- pprint.isrecursive(object) didn't correctly identify recursive objects.
1648 Now it does.
1649
Tim Peters95b3f782001-05-14 18:39:41 +00001650- pprint functions now much faster for large containers (tuple, list, dict).
1651
Tim Peters7b9542a2001-06-10 23:40:19 +00001652- New 'q' and 'Q' format codes in the struct module, corresponding to C
1653 types "long long" and "unsigned long long" (on Windows, __int64). In
1654 native mode, these can be used only when the platform C compiler supports
1655 these types (when HAVE_LONG_LONG is #define'd by the Python config
1656 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001657 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1658 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001659
Guido van Rossum83213cc2001-06-12 16:48:52 +00001660- The site module installs a new built-in function 'help' that invokes
1661 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1662 it displays a message reminding the user to use 'help()' or
1663 'help(object)'.
1664
Tim Petersa814db52001-05-14 07:05:58 +00001665Tests
1666
1667- New test_mutants.py runs dict comparisons where the key and value
1668 comparison operators mutute the dicts randomly during comparison. This
1669 rapidly causes Python to crash under earlier releases (not for the faint
1670 of heart: it can also cause Win9x to freeze or reboot!).
1671
1672- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001673 pprint.isreadable() return sensible results. Also verifies that simple
1674 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001675
Tim Peters4324aa32001-05-28 22:30:08 +00001676C API
1677
1678- Removed the unused last_is_sticky argument from the internal
1679 _PyTuple_Resize(). If this affects you, you were cheating.
1680
1681
Guido van Rossum55a78992001-07-17 17:22:32 +00001682======================================================================
1683
1684
Guido van Rossumffe13be2001-04-16 18:46:45 +00001685What's New in Python 2.1 (final)?
1686=================================
1687
1688We only changed a few things since the last release candidate, all in
1689Python library code:
1690
1691- A bug in the locale module was fixed that affected locales which
1692 define no grouping for numeric formatting.
1693
1694- A few bugs in the weakref module's implementations of weak
1695 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1696 and the test suite was updated to check for these bugs.
1697
1698- An old bug in the os.path.walk() function (introduced in Python
1699 2.0!) was fixed: a non-existent file would cause an exception
1700 instead of being ignored.
1701
1702- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1703 PyChecker.
1704
1705
Guido van Rossum5b08f132001-04-16 02:05:23 +00001706What's New in Python 2.1c2?
1707===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001708
Guido van Rossum5b08f132001-04-16 02:05:23 +00001709A flurry of small changes, and one showstopper fixed in the nick of
1710time made it necessary to release another release candidate. The list
1711here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001712
Guido van Rossum5b08f132001-04-16 02:05:23 +00001713Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001714
Guido van Rossum5b08f132001-04-16 02:05:23 +00001715- Tim discovered a nasty bug in the dictionary code, caused by
1716 PyDict_Next() calling dict_resize(), and the GC code's use of
1717 PyDict_Next() violating an assumption in dict_items(). This was
1718 fixed with considerable amounts of band-aid, but the net effect is a
1719 saner and more robust implementation.
1720
1721- Made a bunch of symbols static that were accidentally global.
1722
1723Build and Ports
1724
1725- The setup.py script didn't check for a new enough version of zlib
1726 (1.1.3 is needed). Now it does.
1727
1728- Changed "make clean" target to also remove shared libraries.
1729
1730- Added a more general warning about the SGI Irix optimizer to README.
1731
1732Library
1733
1734- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1735 omitted the slash between host and file.html.
1736
1737- The mailbox module's _Mailbox class contained a completely broken
1738 and undocumented seek() method. Ripped it out.
1739
1740- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1741 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1742
1743- Fixed a few last-minute bugs in unittest.
1744
1745Extensions
1746
1747- Reverted the patch to the OpenSSL code in socketmodule.c to support
1748 RAND_status() and the EGD, and the subsequent patch that tried to
1749 fix it for pre-0.9.5 versions; the problem with the patch is that on
1750 some systems it issues a warning whenever socket is imported, and
1751 that's unacceptable.
1752
1753Tests
1754
1755- Fixed the pickle tests to work with "import test.test_pickle".
1756
1757- Tweaked test_locale.py to actually run the test Windows.
1758
1759- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1760 not "wb" (which is not a valid mode at all).
1761
1762- Fix pstats browser crashes. Import readline if it exists to make
1763 the user interface nicer.
1764
1765- Add "import thread" to the top of test modules that import the
1766 threading module (test_asynchat and test_threadedtempfile). This
1767 prevents test failures caused by a broken threading module resulting
1768 from a previously caught failed import.
1769
1770- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1771 needed on some platforms (e.g. Solaris 8) when the tests are run
1772 twice in succession.
1773
1774- Skip rather than fail test_sunaudiodev if no audio device is found.
1775
1776
1777What's New in Python 2.1c1?
1778===========================
1779
1780This list was significantly updated when 2.1c2 was released; the 2.1c1
1781release didn't mention most changes that were actually part of 2.1c1:
1782
1783Legal
1784
1785- Copyright was assigned to the Python Software Foundation (PSF) and a
1786 PSF license (very similar to the CNRI license) was added.
1787
1788- The CNRI copyright notice was updated to include 2001.
1789
1790Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001791
Guido van Rossumc9932722001-04-12 02:31:27 +00001792- After a public outcry, assignment to __debug__ is no longer illegal;
1793 instead, a warning is issued. It will become illegal in 2.2.
1794
Guido van Rossum5b08f132001-04-16 02:05:23 +00001795- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1796 "%#x" now always prepends "0x", even if the value is zero.
1797
1798- Fixed some nits in the bytecode compiler.
1799
1800- Fixed core dumps when calling certain kinds of non-functions.
1801
1802- Fixed various core dumps caused by reference count bugs.
1803
1804Build and Ports
1805
1806- Use INSTALL_SCRIPT to install script files.
1807
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001808- New port: SCO Unixware 7, by Billy G. Allie.
1809
Guido van Rossum5b08f132001-04-16 02:05:23 +00001810- Updated RISCOS port.
1811
1812- Updated BeOS port and notes.
1813
1814- Various other porting problems resolved.
1815
1816Library
1817
1818- The TERMIOS and SOCKET modules are now truly obsolete and
1819 unnecessary. Their symbols are incorporated in the termios and
1820 socket modules.
1821
1822- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1823 better tests for pickling.
1824
1825- threading: make Condition.wait() robust against KeyboardInterrupt.
1826
1827- zipfile: add support to zipfile to support opening an archive
1828 represented by an open file rather than a file name. Fix bug where
1829 the archive was not properly closed. Fixed a bug in this bugfix
1830 where flush() was called for a read-only file.
1831
1832- imputil: added an uninstall() method to the ImportManager.
1833
1834- Canvas: fixed bugs in lower() and tkraise() methods.
1835
1836- SocketServer: API change (added overridable close_request() method)
1837 so that the TCP server can explicitly close the request.
1838
1839- pstats: Eric Raymond added a simple interactive statistics browser,
1840 invoked when the module is run as a script.
1841
1842- locale: fixed a problem in format().
1843
1844- webbrowser: made it work when the BROWSER environment variable has a
1845 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1846 KDE 2. Fixed some other nits.
1847
1848- unittest: changes to allow using a different exception than
1849 AssertionError, and added a few more function aliases. Some other
1850 small changes.
1851
1852- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1853
1854- asynchat: fixed a critical bug in asynchat that slipped through the
1855 2.1b2 release. Fixed another rare bug.
1856
1857- Fix some unqualified except: clauses (always a bad code example).
1858
1859XML
1860
1861- pyexpat: new API get_version_string().
1862
1863- Fixed some minidom bugs.
1864
1865Extensions
1866
1867- Fixed a core dump in _weakref. Removed the weakref.mapping()
1868 function (it adds nothing to the API).
1869
1870- Rationalized the use of header files in the readline module, to make
1871 it compile (albeit with some warnings) with the very recent readline
1872 4.2, without breaking for earlier versions.
1873
1874- Hopefully fixed a buffering problem in linuxaudiodev.
1875
1876- Attempted a fix to make the OpenSSL support in the socket module
1877 work again with pre-0.9.5 versions of OpenSSL.
1878
1879Tests
1880
1881- Added a test case for asynchat and asyncore.
1882
1883- Removed coupling between tests where one test failing could break
1884 another.
1885
1886Tools
1887
1888- Ping added an interactive help browser to pydoc, fixed some nits
1889 in the rest of the pydoc code, and added some features to his
1890 inspect module.
1891
1892- An updated python-mode.el version 4.1 which integrates Ken
1893 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1894 much nicer in XEmacs and Emacs. When stepping through your program
1895 with pdb, in either the shell window or the *Python* window, the
1896 source file and line will be tracked by an arrow. Very cool!
1897
1898- IDLE: syntax warnings in interactive mode are changed into errors.
1899
1900- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001901 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001902
1903- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001904
Barry Warsaw11e89c72001-04-11 20:37:57 +00001905
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001906What's New in Python 2.1 beta 2?
1907================================
1908
Guido van Rossum053ae352001-03-22 14:17:21 +00001909(Unlisted are many fixed bugs, more documentation, etc.)
1910
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001911Core language, builtins, and interpreter
1912
Guido van Rossum053ae352001-03-22 14:17:21 +00001913- The nested scopes work (enabled by "from __future__ import
1914 nested_scopes") is completed; in particular, the future now extends
1915 into code executed through exec, eval() and execfile(), and into the
1916 interactive interpreter.
1917
1918- When calling a base class method (e.g. BaseClass.__init__(self)),
1919 this is now allowed even if self is not strictly spoken a class
1920 instance (e.g. when using metaclasses or the Don Beaudry hook).
1921
1922- Slice objects are now comparable but not hashable; this prevents
1923 dict[:] from being accepted but meaningless.
1924
1925- Complex division is now calculated using less braindead algorithms.
1926 This doesn't change semantics except it's more likely to give useful
1927 results in extreme cases. Complex repr() now uses full precision
1928 like float repr().
1929
1930- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1931
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001932- It is illegal to assign to the name __debug__, which is set when the
1933 interpreter starts. It is effectively a compile-time constant.
1934
1935- A warning will be issued if a global statement for a variable
1936 follows a use or assignment of that variable.
1937
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001938Standard library
1939
Guido van Rossum053ae352001-03-22 14:17:21 +00001940- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1941 inspired by JUnit), is now part of the standard library. You now
1942 have a choice of two testing frameworks: unittest requires you to
1943 write testcases as separate code, doctest gathers them from
1944 docstrings. Both approaches have their advantages and
1945 disadvantages.
1946
1947- A new module Tix was added, which wraps the Tix extension library
1948 for Tk. With that module, it is not necessary to statically link
1949 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1950 require" command. See Demo/tix/.
1951
1952- tzparse.py is now obsolete.
1953
1954- In gzip.py, the seek() and tell() methods are removed -- they were
1955 non-functional anyway, and it's better if callers can test for their
1956 existence with hasattr().
1957
1958Python/C API
1959
1960- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1961 that's already in the dictionary during a PyDict_Next() iteration.
1962 This used to fail occasionally when a dictionary resize operation
1963 could be triggered that would rehash all the keys. All other
1964 modifications to the dictionary are still off-limits during a
1965 PyDict_Next() iteration!
1966
1967- New extended APIs related to passing compiler variables around.
1968
1969- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1970 implement isinstance() and issubclass().
1971
1972- Py_BuildValue() now has a "D" conversion to create a Python complex
1973 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001974
Fred Drake4e262a92001-03-22 18:26:47 +00001975- Extensions types which support weak references must now set the
1976 field allocated for the weak reference machinery to NULL themselves;
1977 this is done to avoid the cost of checking each object for having a
1978 weakly referencable type in PyObject_INIT(), since most types are
1979 not weakly referencable.
1980
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001981- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1982 free variables and cell variables to and from the frame's f_locals.
1983
1984- Variants of several functions defined in pythonrun.h have been added
1985 to support the nested_scopes future statement. The variants all end
1986 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1987 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1988 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001989 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001990
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001991Distutils
1992
1993- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1994 into the release tree.
1995
Tim Peters0e57abf2001-05-02 07:39:38 +00001996- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001997 (an uninstaller, more customization of the installer's display)
1998
1999- from Jack Jansen: added Mac-specific code to generate a dialog for
2000 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002001 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002002 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002003
2004- added 'platforms' and 'keywords' to the set of metadata that can be
2005 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002006
2007- applied patches from Jason Tishler to make the compiler class work with
2008 Cygwin.
2009
2010
Tim Peters2fe289a2001-03-01 22:19:38 +00002011What's New in Python 2.1 beta 1?
2012================================
Tim Petersd66595f2001-02-04 03:09:53 +00002013
2014Core language, builtins, and interpreter
2015
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002016- Following an outcry from the community about the amount of code
2017 broken by the nested scopes feature introduced in 2.1a2, we decided
2018 to make this feature optional, and to wait until Python 2.2 (or at
2019 least 6 months) to make it standard. The option can be enabled on a
2020 per-module basis by adding "from __future__ import nested_scopes" at
2021 the beginning of a module (before any other statements, but after
2022 comments and an optional docstring). See PEP 236 (Back to the
2023 __future__) for a description of the __future__ statement. PEP 227
2024 (Statically Nested Scopes) has been updated to reflect this change,
2025 and to clarify the semantics in a number of endcases.
2026
2027- The nested scopes code, when enabled, has been hardened, and most
2028 bugs and memory leaks in it have been fixed.
2029
2030- Compile-time warnings are now generated for a number of conditions
2031 that will break or change in meaning when nested scopes are enabled:
2032
2033 - Using "from...import *" or "exec" without in-clause in a function
2034 scope that also defines a lambda or nested function with one or
2035 more free (non-local) variables. The presence of the import* or
2036 bare exec makes it impossible for the compiler to determine the
2037 exact set of local variables in the outer scope, which makes it
2038 impossible to determine the bindings for free variables in the
2039 inner scope. To avoid the warning about import *, change it into
2040 an import of explicitly name object, or move the import* statement
2041 to the global scope; to avoid the warning about bare exec, use
2042 exec...in... (a good idea anyway -- there's a possibility that
2043 bare exec will be deprecated in the future).
2044
2045 - Use of a global variable in a nested scope with the same name as a
2046 local variable in a surrounding scope. This will change in
2047 meaning with nested scopes: the name in the inner scope will
2048 reference the variable in the outer scope rather than the global
2049 of the same name. To avoid the warning, either rename the outer
2050 variable, or use a global statement in the inner function.
2051
Neil Schemenauera35c6882001-02-27 04:45:05 +00002052- An optional object allocator has been included. This allocator is
2053 optimized for Python objects and should be faster and use less memory
2054 than the standard system allocator. It is not enabled by default
2055 because of possible thread safety problems. The allocator is only
2056 protected by the Python interpreter lock and it is possible that some
2057 extension modules require a thread safe allocator. The object
2058 allocator can be enabled by providing the "--with-pymalloc" option to
2059 configure.
2060
Tim Petersd66595f2001-02-04 03:09:53 +00002061Standard library
2062
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002063- pyexpat now detects the expat version if expat.h defines it. A
2064 number of additional handlers are provided, which are only available
2065 since expat 1.95. In addition, the methods SetParamEntityParsing and
2066 GetInputContext of Parser objects are available with 1.95.x
2067 only. Parser objects now provide the ordered_attributes and
2068 specified_attributes attributes. A new module expat.model was added,
2069 which offers a number of additional constants if 1.95.x is used.
2070
2071- xml.dom offers the new functions registerDOMImplementation and
2072 getDOMImplementation.
2073
2074- xml.dom.minidom offers a toprettyxml method. A number of DOM
2075 conformance issues have been resolved. In particular, Element now
2076 has an hasAttributes method, and the handling of namespaces was
2077 improved.
2078
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002079- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2080 getting information about live Python code, and pydoc.py, a module
2081 for interactively converting docstrings to HTML or text.
2082 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002083 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002084 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2085 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002086
Tim Peters1eff7962001-03-01 02:31:33 +00002087- New library module difflib.py, primarily packaging the SequenceMatcher
2088 class at the heart of the popular ndiff.py file-comparison tool.
2089
2090- doctest.py (a framework for verifying Python code examples in docstrings)
2091 is now part of the std library.
2092
Tim Petersd66595f2001-02-04 03:09:53 +00002093Windows changes
2094
Guido van Rossume3955a82001-03-02 14:05:59 +00002095- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2096 small GUI that lets you browse the module docstrings using your
2097 default web browser.
2098
Tim Peters1eff7962001-03-01 02:31:33 +00002099- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2100 Platforms) is implemented. See
2101
2102 http://python.sourceforge.net/peps/pep-0235.html
2103
2104 for full details, especially the "Current Lower-Left Semantics" section.
2105 The new Windows import rules are simpler than before:
2106
2107 A. If the PYTHONCASEOK environment variable exists, same as
2108 before: silently accept the first case-insensitive match of any
2109 kind; raise ImportError if none found.
2110
2111 B. Else search sys.path for the first case-sensitive match; raise
2112 ImportError if none found.
2113
2114 The same rules have been implented on other platforms with case-
2115 insensitive but case-preserving filesystems too (including Cygwin, and
2116 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002117
Tim Peters25a9ce32001-02-19 07:06:36 +00002118- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2119 what it's supposed to do (and does do under NT and 2000) via direct
2120 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002121 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002122 all Win9x systems before.
2123
Tim Peters1eff7962001-03-01 02:31:33 +00002124- Build: Subproject _test (effectively) renamed to _testcapi.
2125
Tim Peters2fe289a2001-03-01 22:19:38 +00002126New platforms
2127
2128- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2129 Thanks to Steven Majewski!
2130
2131- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2132 Tishler!
2133
Guido van Rossum9089b272001-03-02 06:49:50 +00002134- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2135 Schwertberger! See RISCOS/README for more information -- it seems
2136 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002137 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002138
Tim Peters25a9ce32001-02-19 07:06:36 +00002139
Tim Petersd7b5e882001-01-25 03:36:26 +00002140What's New in Python 2.1 alpha 2?
2141=================================
Tim Peters40ead762001-01-27 05:35:26 +00002142
Tim Petersd7b5e882001-01-25 03:36:26 +00002143Core language, builtins, and interpreter
2144
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002145- Scopes nest. If a name is used in a function or class, but is not
2146 local, the definition in the nearest enclosing function scope will
2147 be used. One consequence of this change is that lambda statements
2148 could reference variables in the namespaces where the lambda is
2149 defined. In some unusual cases, this change will break code.
2150
2151 In all previous version of Python, names were resolved in exactly
2152 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002153 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002154 function A is defined within a function B, the names bound in B are
2155 not visible in A. The new rules make names bound in B visible in A,
2156 unless A contains a name binding that hides the binding in B.
2157
2158 Section 4.1 of the reference manual describes the new scoping rules
2159 in detail. The test script in Lib/test/test_scope.py demonstrates
2160 some of the effects of the change.
2161
2162 The new rules will cause existing code to break if it defines nested
2163 functions where an outer function has local variables with the same
2164 name as globals or builtins used by the inner function. Example:
2165
2166 def munge(str):
2167 def helper(x):
2168 return str(x)
2169 if type(str) != type(''):
2170 str = helper(str)
2171 return str.strip()
2172
2173 Under the old rules, the name str in helper() is bound to the
2174 builtin function str(). Under the new rules, it will be bound to
2175 the argument named str and an error will occur when helper() is
2176 called.
2177
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002178- The compiler will report a SyntaxError if "from ... import *" occurs
2179 in a function or class scope. The language reference has documented
2180 that this case is illegal, but the compiler never checked for it.
2181 The recent introduction of nested scope makes the meaning of this
2182 form of name binding ambiguous. In a future release, the compiler
2183 may allow this form when there is no possibility of ambiguity.
2184
Tim Peters40ead762001-01-27 05:35:26 +00002185- repr(string) is easier to read, now using hex escapes instead of octal,
2186 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2187
2188 >>> "\texample \r\n" + chr(0) + chr(255)
2189 '\texample \r\n\x00\xff' # in 2.1
2190 '\011example \015\012\000\377' # in 2.0
2191
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002192- Functions are now compared and hashed by identity, not by value, since
2193 the func_code attribute is writable.
2194
Fred Drakefb9d7122001-02-01 20:00:40 +00002195- Weak references (PEP 205) have been added. This involves a few
2196 changes in the core, an extension module (_weakref), and a Python
2197 module (weakref). The weakref module is the public interface. It
2198 includes support for "explicit" weak references, proxy objects, and
2199 mappings with weakly held values.
2200
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002201- A 'continue' statement can now appear in a try block within the body
2202 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002203 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002204
Tim Petersd7b5e882001-01-25 03:36:26 +00002205Standard library
2206
Barry Warsaw30dbd142001-01-31 22:14:01 +00002207- mailbox.py now has a new class, PortableUnixMailbox which is
2208 identical to UnixMailbox but uses a more portable scheme for
2209 determining From_ separators. Also, the constructors for all the
2210 classes in this module have a new optional `factory' argument, which
2211 is a callable used when new message classes must be instantiated by
2212 the next() method.
2213
Tim Petersd7b5e882001-01-25 03:36:26 +00002214- random.py is now self-contained, and offers all the functionality of
2215 the now-deprecated whrandom.py. See the docs for details. random.py
2216 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002217 and restoring the internal state of the generator; and jumpahead(n),
2218 for quickly forcing the internal state to be the same as if n calls to
2219 random() had been made. The latter is particularly useful for multi-
2220 threaded programs, creating one instance of the random.Random() class for
2221 each thread, then using .jumpahead() to force each instance to use a
2222 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002223
Tim Peters0de88fc2001-02-01 04:59:18 +00002224- random.py's seed() function is new. For bit-for-bit compatibility with
2225 prior releases, use the whseed function instead. The new seed function
2226 addresses two problems: (1) The old function couldn't produce more than
2227 about 2**24 distinct internal states; the new one about 2**45 (the best
2228 that can be done in the Wichmann-Hill generator). (2) The old function
2229 sometimes produced identical internal states when passed distinct
2230 integers, and there was no simple way to predict when that would happen;
2231 the new one guarantees to produce distinct internal states for all
2232 arguments in [0, 27814431486576L).
2233
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002234- The socket module now supports raw packets on Linux. The socket
2235 family is AF_PACKET.
2236
Tim Peters9ea17ac2001-02-02 05:57:15 +00002237- test_capi.py is a start at running tests of the Python C API. The tests
2238 are implemented by the new Modules/_testmodule.c.
2239
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002240- A new extension module, _symtable, provides provisional access to the
2241 internal symbol table used by the Python compiler. A higher-level
2242 interface will be added on top of _symtable in a future release.
2243
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002244- Removed the obsolete soundex module.
2245
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002246- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2247 the isSameNode method; NamedNodeMap the get method.
2248
2249- xml.sax.expatreader supports the lexical handler property; it
2250 generates comment, startCDATA, and endCDATA events.
2251
Tim Petersee826f82001-01-31 19:39:44 +00002252Windows changes
2253
2254- Build procedure: the zlib project is built in a different way that
2255 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002256 the zlib binary used. See PCbuild\readme.txt for details. Your old
2257 zlib-related directories can be deleted; you'll need to download fresh
2258 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002259
Tim Peters9ea17ac2001-02-02 05:57:15 +00002260- Build: New subproject _test for the benefit of test_capi.py (see above).
2261
Tim Petersb16c56f2001-02-02 21:24:51 +00002262- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2263 interface to some Python compiler internals).
2264
2265- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002266 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002267
Tim Petersa3a3a032000-11-30 05:22:44 +00002268What's New in Python 2.1 alpha 1?
2269=================================
2270
2271Core language, builtins, and interpreter
2272
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002273- There is a new Unicode companion to the PyObject_Str() API
2274 called PyObject_Unicode(). It behaves in the same way as the
2275 former, but assures that the returned value is an Unicode object
2276 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002277
Guido van Rossumf98eda02001-01-17 15:54:45 +00002278- The comparison operators support "rich comparison overloading" (PEP
2279 207). C extension types can provide a rich comparison function in
2280 the new tp_richcompare slot in the type object. The cmp() function
2281 and the C function PyObject_Compare() first try the new rich
2282 comparison operators before trying the old 3-way comparison. There
2283 is also a new C API PyObject_RichCompare() (which also falls back on
2284 the old 3-way comparison, but does not constrain the outcome of the
2285 rich comparison to a Boolean result).
2286
2287 The rich comparison function takes two objects (at least one of
2288 which is guaranteed to have the type that provided the function) and
2289 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2290 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2291 object, which may be NotImplemented (in which case the tp_compare
2292 slot function is used as a fallback, if defined).
2293
2294 Classes can overload individual comparison operators by defining one
2295 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002296 __ge__. There are no explicit "reflected argument" versions of
2297 these; instead, __lt__ and __gt__ are each other's reflection,
2298 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2299 reflection (similar at the C level). No other implications are
2300 made; in particular, Python does not assume that == is the Boolean
2301 inverse of !=, or that < is the Boolean inverse of >=. This makes
2302 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002303
2304 Classes or types that want to implement (in)equality tests but not
2305 the ordering operators (i.e. unordered types) should implement ==
2306 and !=, and raise an error for the ordering operators.
2307
Guido van Rossuma88479f2001-01-18 14:28:08 +00002308 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002309 Boolean; e.g. a matrix type might want to return a matrix of bits
2310 for A < B, giving elementwise comparisons. Such types should ensure
2311 that any interpretation of their value in a Boolean context raises
2312 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2313 at the C level) to always raise an exception.
2314
Guido van Rossuma88479f2001-01-18 14:28:08 +00002315- Complex numbers use rich comparisons to define == and != but raise
2316 an exception for <, <=, > and >=. Unfortunately, this also means
2317 that cmp() of two complex numbers raises an exception when the two
2318 numbers differ. Since it is not mathematically meaningful to compare
2319 complex numbers except for equality, I hope that this doesn't break
2320 too much code.
2321
Tim Peters3389f192001-02-18 08:48:49 +00002322- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002323 not defined by the language, other than that it's arbitrary but
2324 consistent (see the Reference Manual). An implementation detail changed
2325 in 2.1a1 such that None now compares less than any other object. Code
2326 relying on this new behavior (like code that relied on the previous
2327 behavior) does so at its own risk.
2328
Barry Warsaw573b5412001-01-15 20:43:18 +00002329- Functions and methods now support getting and setting arbitrarily
2330 named attributes (PEP 232). Functions have a new __dict__
2331 (a.k.a. func_dict) which hold the function attributes. Methods get
2332 and set attributes on their underlying im_func. It is a TypeError
2333 to set an attribute on a bound method.
2334
Guido van Rossum051e3352001-01-15 19:11:10 +00002335- The xrange() object implementation has been improved so that
2336 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2337 limitation that in this case len(xrange(sys.maxint)) can't be
2338 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2339 work fine as long as the index i doesn't actually reach 2**31.
2340 (Python uses regular ints for sequence and string indices; fixing
2341 that is much more work.)
2342
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002343- Two changes to from...import:
2344
Guido van Rossumba381232001-02-03 15:06:40 +00002345 1) "from M import X" now works even if (after loading module M)
2346 sys.modules['M'] is not a real module; it's basically a getattr()
2347 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002348
2349 2) "from M import *" now looks for M.__all__ to decide which names to
2350 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2351 filters out names starting with '_' as before. Whether or not
2352 __all__ exists, there's no restriction on the type of M.
2353
Guido van Rossumf61f1662001-01-10 20:13:55 +00002354- File objects have a new method, xreadlines(). This is the fastest
2355 way to iterate over all lines in a file:
2356
2357 for line in file.xreadlines():
2358 ...do something to line...
2359
2360 See the xreadlines module (mentioned below) for how to do this for
2361 other file-like objects.
2362
2363- Even if you don't use file.xreadlines(), you may expect a speedup on
2364 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002365 quite a bit in platform-specific ways: on systems (like Linux) that
2366 support flockfile(), getc_unlocked(), and funlockfile(), those are
2367 used by default. On systems (like Windows) without getc_unlocked(),
2368 a complicated (but still thread-safe) method using fgets() is used by
2369 default.
2370
Tim Petersd52269b2001-01-25 06:23:18 +00002371 You can force use of the fgets() method by #define'ing
2372 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002373 getc_unlocked()).
2374
Tim Petersd52269b2001-01-25 06:23:18 +00002375 You can force fgets() not to be used by #define'ing
2376 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002377 test_bufio.py fails -- and let us know if it does!).
2378
2379- In addition, the fileinput module, while still slower than the other
2380 methods on most platforms, has been sped up too, by using
2381 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002382
2383- Support for run-time warnings has been added, including a new
2384 command line option (-W) to specify the disposition of warnings.
2385 See the description of the warnings module below.
2386
2387- Extensive changes have been made to the coercion code. This mostly
2388 affects extension modules (which can now implement mixed-type
2389 numerical operators without having to use coercion), but
2390 occasionally, in boundary cases the coercion semantics have changed
2391 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002392 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002393 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002394 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002395
Guido van Rossumf98eda02001-01-17 15:54:45 +00002396- In connection with the coercion changes, a new built-in singleton
2397 object, NotImplemented is defined. This can be returned for
2398 operations that wish to indicate they are not implemented for a
2399 particular combination of arguments. From C, this is
2400 Py_NotImplemented.
2401
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002402- The interpreter accepts now bytecode files on the command line even
2403 if they do not have a .pyc or .pyo extension. On Linux, after executing
2404
Martin v. Löwise214baa2001-02-04 22:37:56 +00002405import imp,sys,string
2406magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2407reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2408open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002409
2410 any byte code file can be used as an executable (i.e. as an argument
2411 to execve(2)).
2412
Tim Peters9940b802000-12-01 07:59:35 +00002413- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002414 character. In 1.6 and earlier, they never produced a sign,
2415 and raised an error if the value of the long was too large
2416 to fit in a Python int. In 2.0, they produced a sign if and
2417 only if too large to fit in an int. This was inconsistent
2418 across platforms (because the size of an int varies across
2419 platforms), and inconsistent with hex() and oct(). Example:
2420
2421 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002422 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002423 'ffffffbe' # in 2.0 and before, on 32-bit machines
2424 >>> hex(-0x42L)
2425 '-0x42L' # in all versions of Python
2426
Tim Peters9940b802000-12-01 07:59:35 +00002427 The behavior of %d formats for negative Python longs remains
2428 the same as in 2.0 (although in 1.6 and before, they raised
2429 an error if the long didn't fit in a Python int).
2430
2431 %u formats don't make sense for Python longs, but are allowed
2432 and treated the same as %d in 2.1. In 2.0, a negative long
2433 formatted via %u produced a sign if and only if too large to
2434 fit in an int. In 1.6 and earlier, a negative long formatted
2435 via %u raised an error if it was too big to fit in an int.
2436
Guido van Rossum3661d392000-12-12 22:10:31 +00002437- Dictionary objects have an odd new method, popitem(). This removes
2438 an arbitrary item from the dictionary and returns it (in the form of
2439 a (key, value) pair). This can be useful for algorithms that use a
2440 dictionary as a bag of "to do" items and repeatedly need to pick one
2441 item. Such algorithms normally end up running in quadratic time;
2442 using popitem() they can usually be made to run in linear time.
2443
Tim Peters36cdad12000-12-29 02:06:45 +00002444Standard library
2445
Thomas Woutersfe385252001-01-19 23:16:56 +00002446- In the time module, the time argument to the functions strftime,
2447 localtime, gmtime, asctime and ctime is now optional, defaulting to
2448 the current time (in the local timezone).
2449
Guido van Rossumda91f222001-01-15 16:36:08 +00002450- The ftplib module now defaults to passive mode, which is deemed a
2451 more useful default given that clients are often inside firewalls
2452 these days. Note that this could break if ftplib is used to connect
2453 to a *server* that is inside a firewall, from outside; this is
2454 expected to be a very rare situation. To fix that, you can call
2455 ftp.set_pasv(0).
2456
Martin v. Löwis10a27872001-01-13 09:54:41 +00002457- The module site now treats .pth files not only for path configuration,
2458 but also supports extensions to the initialization code: Lines starting
2459 with import are executed.
2460
Guido van Rossumf61f1662001-01-10 20:13:55 +00002461- There's a new module, warnings, which implements a mechanism for
2462 issuing and filtering warnings. There are some new built-in
2463 exceptions that serve as warning categories, and a new command line
2464 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2465 turns warnings into errors). warnings.warn(message[, category])
2466 issues a warning message; this can also be called from C as
2467 PyErr_Warn(category, message).
2468
2469- A new module xreadlines was added. This exports a single factory
2470 function, xreadlines(). The intention is that this code is the
2471 absolutely fastest way to iterate over all lines in an open
2472 file(-like) object:
2473
2474 import xreadlines
2475 for line in xreadlines.xreadlines(file):
2476 ...do something to line...
2477
2478 This is equivalent to the previous the speed record holder using
2479 file.readlines(sizehint). Note that if file is a real file object
2480 (as opposed to a file-like object), this is equivalent:
2481
2482 for line in file.xreadlines():
2483 ...do something to line...
2484
Tim Peters36cdad12000-12-29 02:06:45 +00002485- The bisect module has new functions bisect_left, insort_left,
2486 bisect_right and insort_right. The old names bisect and insort
2487 are now aliases for bisect_right and insort_right. XXX_right
2488 and XXX_left methods differ in what happens when the new element
2489 compares equal to one or more elements already in the list: the
2490 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002491 right. Code that doesn't care where equal elements end up should
2492 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002493
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002494- The new curses.panel module wraps the panel library that forms part
2495 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2496
Guido van Rossumf61f1662001-01-10 20:13:55 +00002497- The SocketServer module now sets the allow_reuse_address flag by
2498 default in the TCPServer class.
2499
2500- A new function, sys._getframe(), returns the stack frame pointer of
2501 the caller. This is intended only as a building block for
2502 higher-level mechanisms such as string interpolation.
2503
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002504- The pyexpat module supports a number of new handlers, which are
2505 available only in expat 1.2. If invocation of a callback fails, it
2506 will report an additional frame in the traceback. Parser objects
2507 participate now in garbage collection. If expat reports an unknown
2508 encoding, pyexpat will try to use a Python codec; that works only
2509 for single-byte charsets. The parser type objects is exposed as
2510 XMLParserObject.
2511
2512- xml.dom now offers standard definitions for symbolic node type and
2513 exception code constants, and a hierarchy of DOM exceptions. minidom
2514 was adjusted to use them.
2515
2516- The conformance of xml.dom.minidom to the DOM specification was
2517 improved. It detects a number of additional error cases; the
2518 previous/next relationship works even when the tree is modified;
2519 Node supports the normalize() method; NamedNodeMap, DocumentType and
2520 DOMImplementation classes were added; Element supports the
2521 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2522 method.
2523
Guido van Rossumf61f1662001-01-10 20:13:55 +00002524Build issues
2525
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002526- For Unix (and Unix-compatible) builds, configuration and building of
2527 extension modules is now greatly automated. Rather than having to
2528 edit the Modules/Setup file to indicate which modules should be
2529 built and where their include files and libraries are, a
2530 distutils-based setup.py script now takes care of building most
2531 extension modules. All extension modules built this way are built
2532 as shared libraries. Only a few modules that must be linked
2533 statically are still listed in the Setup file; you won't need to
2534 edit their configuration.
2535
2536- Python should now build out of the box on Cygwin. If it doesn't,
2537 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002538
2539- Python now always uses its own (renamed) implementation of getopt()
2540 -- there's too much variation among C library getopt()
2541 implementations.
2542
2543- C++ compilers are better supported; the CXX macro is always set to a
2544 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002545
Tim Petersd92dfe02000-12-12 01:18:41 +00002546Windows changes
2547
2548- select module: By default under Windows, a select() call
2549 can specify no more than 64 sockets. Python now boosts
2550 this Microsoft default to 512. If you need even more than
2551 that, see the MS docs (you'll need to #define FD_SETSIZE
2552 and recompile Python from source).
2553
Guido van Rossumf61f1662001-01-10 20:13:55 +00002554- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2555 subdirectory is no more!
2556
Tim Petersa3a3a032000-11-30 05:22:44 +00002557
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002558What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002559=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002560
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002561Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002562changes are in the file HISTORY. If you are making the jump directly
2563from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2564HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002565
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002566Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2567the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2568http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002569
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002570--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002571
2572======================================================================
2573
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002574What's new in 2.0 (since release candidate 1)?
2575==============================================
2576
2577Standard library
2578
2579- The copy_reg module was modified to clarify its intended use: to
2580 register pickle support for extension types, not for classes.
2581 pickle() will raise a TypeError if it is passed a class.
2582
2583- Fixed a bug in gettext's "normalize and expand" code that prevented
2584 it from finding an existing .mo file.
2585
2586- Restored support for HTTP/0.9 servers in httplib.
2587
Tim Peters989b7b92000-10-16 20:24:53 +00002588- The math module was changed to stop raising OverflowError in case of
2589 underflow, and return 0 instead in underflow cases. Whether Python
2590 used to raise OverflowError in case of underflow was platform-
2591 dependent (it did when the platform math library set errno to ERANGE
2592 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002593
2594- Fixed a bug in StringIO that occurred when the file position was not
2595 at the end of the file and write() was called with enough data to
2596 extend past the end of the file.
2597
2598- Fixed a bug that caused Tkinter error messages to get lost on
2599 Windows. The bug was fixed by replacing direct use of
2600 interp->result with Tcl_GetStringResult(interp).
2601
2602- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2603 redirect response.
2604
2605- Several changes were made to distutils: Some debugging code was
2606 removed from util. Fixed the installer used when an external zip
2607 program (like WinZip) is not found; the source code for this
2608 installer is in Misc/distutils. check_lib() was modified to behave
2609 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2610 test for whether installed modules are on sys.path was changed to
2611 use both normcase() and normpath().
2612
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002613- Several minor bugs were fixed in the xml package (the minidom,
2614 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002615
2616- The regression test driver (regrtest.py) behavior when invoked with
2617 -l changed: It now reports a count of objects that are recognized as
2618 garbage but not freed by the garbage collector.
2619
Tim Peters989b7b92000-10-16 20:24:53 +00002620- The regression test for the math module was changed to test
2621 exceptional behavior when the test is run in verbose mode. Python
2622 cannot yet guarantee consistent exception behavior across platforms,
2623 so the exception part of test_math is run only in verbose mode, and
2624 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002625
2626Internals
2627
2628- PyOS_CheckStack() has been disabled on Win64, where it caused
2629 test_sre to fail.
2630
2631Build issues
2632
2633- Changed compiler flags, so that gcc is always invoked with -Wall and
2634 -Wstrict-prototypes. Users compiling Python with GCC should see
2635 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002636 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002637 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002638
Tim Petersa3a3a032000-11-30 05:22:44 +00002639- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002640
2641Tools and other miscellany
2642
2643- The compiler in Tools/compiler was updated to support the new
2644 language features introduced in 2.0: extended print statement, list
2645 comprehensions, and augmented assignments. The new compiler should
2646 also be backwards compatible with Python 1.5.2; the compiler will
2647 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002648 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002649
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002650What's new in 2.0 release candidate 1 (since beta 2)?
2651=====================================================
2652
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002653What is release candidate 1?
2654
2655We believe that release candidate 1 will fix all known bugs that we
2656intend to fix for the 2.0 final release. This release should be a bit
2657more stable than the previous betas. We would like to see even more
2658widespread testing before the final release, so we are producing this
2659release candidate. The final release will be exactly the same unless
2660any show-stopping (or brown bag) bugs are found by testers of the
2661release candidate.
2662
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002663All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002664to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002665
2666Core language, builtins, and interpreter
2667
2668- A bug that caused crashes when __coerce__ was used with augmented
2669 assignment, e.g. +=, was fixed.
2670
2671- Raise ZeroDivisionError when raising zero to a negative number,
2672 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2673 power operator and the result of math.pow(0.0, -2.0) will vary by
2674 platform. On Linux, it raises a ValueError.
2675
2676- A bug in Unicode string interpolation was fixed that occasionally
2677 caused errors with formats including "%%". For example, the
2678 following expression "%% %s" % u"abc" no longer raises a TypeError.
2679
2680- Compilation of deeply nested expressions raises MemoryError instead
2681 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2682
2683- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2684 rendering them useless. They are now written in binary mode again.
2685
2686Standard library
2687
2688- Keyword arguments are now accepted for most pattern and match object
2689 methods in SRE, the standard regular expression engine.
2690
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002691- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002692 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002693
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002694- Several bugs in the Unicode handling and error handling in _tkinter
2695 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002696
2697- Fix memory management errors in Merge() and Tkapp_Call() routines.
2698
2699- Several changes were made to cStringIO to make it compatible with
2700 the file-like object interface and with StringIO. If operations are
2701 performed on a closed object, an exception is raised. The truncate
2702 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002703 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002704
2705- There were many changes made to the linuxaudiodev module and its
2706 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002707 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002708
2709 Note that this module is named poorly, because it should work
2710 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002711 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002712
2713 The module now raises exceptions when errors occur instead of
2714 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2715 audio) and defines a getptr() method that calls the
2716 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2717
2718- The library_version attribute, introduced in an earlier beta, was
2719 removed because it can not be supported with early versions of the C
2720 readline library, which provides no way to determine the version at
2721 compile-time.
2722
2723- The binascii module is now enabled on Win64.
2724
Tim Peters46446d62000-10-09 21:19:31 +00002725- tokenize.py no longer suffers "recursion depth" errors when parsing
2726 programs with very long string literals.
2727
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002728Internals
2729
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002730- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002731 which is called when the interpreter starts up to determine where
2732 the standard library is installed. These vulnerabilities affect all
2733 previous versions of Python and can be exploited by setting very
2734 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2735 setuid Python script, although use of the wrapper in
2736 Misc/setuid-prog.c will eliminate the vulnerability.
2737
2738- Fixed garbage collection bugs in instance creation that were
2739 triggered when errors occurred during initialization. The solution,
2740 applied in cPickle and in PyInstance_New(), is to call
2741 PyObject_GC_Init() after the initialization of the object's
2742 container attributes is complete.
2743
2744- pyexpat adds definitions of PyModule_AddStringConstant and
2745 PyModule_AddObject if the Python version is less than 2.0, which
2746 provides compatibility with PyXML on Python 1.5.2.
2747
2748- If the platform has a bogus definition for LONG_BIT (the number of
2749 bits in a long), an error will be reported at compile time.
2750
2751- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2752 collection crashes and possibly other, unreported crashes.
2753
2754- Fixed a memory leak in _PyUnicode_Fini().
2755
2756Build issues
2757
2758- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002759 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002760 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002761
2762- The mmap.PAGESIZE constant is now initialized using sysconf when
2763 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2764
2765- The md5 file should now compile on all platforms.
2766
2767- The select module now compiles on platforms that do not define
2768 POLLRDNORM and related constants.
2769
2770- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002771 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002772
Jeremy Hylton10921202000-10-09 18:34:12 +00002773- BeOS: A number of changes were made to the build and installation
2774 process. ar-fake now operates on a directory of object files.
2775 dl_export.h is gone, and its macros now appear on the mwcc command
2776 line during build on PPC BeOS.
2777
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002778- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002779 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002780
2781- Cygwin: Support for shared libraries, Tkinter, and sockets.
2782
2783- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2784
2785Tools and other miscellany
2786
2787- Removed debugging prints from main used with freeze.
2788
Tim Peters46446d62000-10-09 21:19:31 +00002789- IDLE auto-indent no longer crashes when it encounters Unicode
2790 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002791
2792What's new in 2.0 beta 2 (since beta 1)?
2793========================================
2794
2795Core language, builtins, and interpreter
2796
Tim Peters482c0212000-09-26 06:33:09 +00002797- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002799
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002800- Add -h and -V command line options to print the usage message and
2801 Python version number and exit immediately.
2802
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002803- eval() and exec accept Unicode objects as code parameters.
2804
2805- getattr() and setattr() now also accept Unicode objects for the
2806 attribute name, which are converted to strings using the default
2807 encoding before lookup.
2808
2809- Multiplication on string and Unicode now does proper bounds
2810 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2811 string is too long."
2812
2813- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002814 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002815
Jeremy Hylton1b618592000-09-26 05:32:36 +00002816
2817Standard library and extensions
2818
Guido van Rossum5b08f132001-04-16 02:05:23 +00002819- socket module: the OpenSSL code now adds support for RAND_status()
2820 and EGD (Entropy Gathering Device).
2821
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002822- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002823 argument checking; it still takes no arguments.
2824
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002825- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002826
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002827- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002828
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002829- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002830
2831- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002832 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002833
2834- copy: Copy Unicode objects atomically.
2835
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002836- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002837
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002838- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002839
Fred Drake67233bc2000-09-26 16:40:27 +00002840- dbm: Add get() and setdefault() methods to dbm object. Add constant
2841 `library' to module that names the library used. Added doc strings
2842 and method names to error messages. Uses configure to determine
2843 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2844 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002845
2846- distutils: Update to version 0.9.3.
2847
2848- dl: Add several dl.RTLD_ constants.
2849
2850- fpectl: Now supported on FreeBSD.
2851
2852- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2853 found by the collector will be saved in gc.garbage. This is useful
2854 for debugging a program that creates reference cycles.
2855
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002856- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002857 of HTTP class. Do not close socket on zero-length response. Do not
2858 crash when server sends invalid content-length header.
2859
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002860- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002861
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002862- marshal: When reading a short, sign-extend on platforms where shorts
2863 are bigger than 16 bits. When reading a long, repair the unportable
2864 sign extension that was being done for 64-bit machines. (It assumed
2865 that signed right shift sign-extends.)
2866
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002867- operator: Add contains(), invert(), __invert__() as aliases for
2868 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002869
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002870- os: Add support for popen2() and popen3() on all platforms where
2871 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002872
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002873- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002874 clicking on a file in Explorer (or passing the file name to the
2875 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002876
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002877- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002878 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002879
2880- pickle: Now raises ValueError when an invalid pickle that contains
2881 a non-string repr where a string repr was expected. This behavior
2882 matches cPickle.
2883
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002884- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002885
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002886- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002887
2888- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002889 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002890 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002891
2892- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002893 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002894
2895- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002896 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002897 few cycles during startup since the first call to
2898 setdefaultencoding() will initialize the codec registry and the
2899 encodings package.
2900
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002901- socket: Support for size hint in readlines() method of object returned
2902 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002903
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002904- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002905 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002906 is followed by whitespace.
2907
Tim Petersa3a3a032000-11-30 05:22:44 +00002908- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002909
2910- struct: Check ranges for bytes and shorts.
2911
2912- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002913 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002914
2915- Tkinter: Image objects are now guaranteed to have unique ids. Set
2916 event.delta to zero if Tk version doesn't support mousewheel.
2917 Removed some debugging prints.
2918
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002919- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002920
Fred Drake67233bc2000-09-26 16:40:27 +00002921- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002922 which works around a bug in Norton AntiVirus 2000 that leads directly
2923 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002924
2925- xml: New version detection code allows PyXML to override standard
2926 XML package if PyXML version is greater than 0.6.1.
2927
Fred Drake64bb3802000-09-26 16:21:35 +00002928- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2929 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2930 tree only for nodes which are sufficiently interesting to a specific
2931 application. Does not provide the HTML-specific extensions. Still
2932 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002933
Fred Drake64bb3802000-09-26 16:21:35 +00002934- xml.sax: SAX 2 support for Python, including all the handler
2935 interfaces needed to process XML 1.0 compliant XML. Some
2936 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002937
Fred Drake64bb3802000-09-26 16:21:35 +00002938- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2939 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002940
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002941
Jeremy Hylton1b618592000-09-26 05:32:36 +00002942C API
2943
2944- Add three new convenience functions for module initialization --
2945 PyModule_AddObject(), PyModule_AddIntConstant(), and
2946 PyModule_AddStringConstant().
2947
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002948- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002949 removed and add #error to Python.h if NULL isn't defined after
2950 #include of stdio.h.
2951
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002952- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002953 backwards compatibility (at the source level) with old extensions.
2954
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002955- A wrapper API was added for signal() and sigaction(). Instead of
2956 either function, always use PyOS_getsig() to get a signal handler
2957 and PyOS_setsig() to set one. A new convenience typedef
2958 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002959
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002960- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002961 internal data buffer and size of a string object -- or the default
2962 encoded version of a Unicode object.
2963
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002964- PyString_Size() and PyString_AsString() accept Unicode objects.
2965
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002966- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002967 exists). INT_MAX and LONG_MAX will always be defined, even if
2968 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002969
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002970- PyFloat_FromString takes a second argument, pend, that was
2971 effectively useless. It is now officially useless but preserved for
2972 backwards compatibility. If the pend argument is not NULL, *pend is
2973 set to NULL.
2974
2975- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2976 for the attribute name. See note on getattr() above.
2977
2978- A few bug fixes to argument processing for Unicode.
2979 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2980 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2981 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002982 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002983
2984- Py_BuildValue accepts B format (for bgen-generated code).
2985
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002986
Jeremy Hylton1b618592000-09-26 05:32:36 +00002987Internals
2988
2989- On Unix, fix code for finding Python installation directory so that
2990 it works when argv[0] is a relative path.
2991
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002992- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002993 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002994 rather than by generating a copy of the object.
2995
Tim Peters482c0212000-09-26 06:33:09 +00002996- Several of the internal Unicode tables are much smaller now, and
2997 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002998
Jeremy Hylton97693b02000-09-26 17:42:51 +00002999- In the garbage collector: Fixed bug in collection of tuples. Fixed
3000 bug that caused some instances to be removed from the container set
3001 while they were still live. Fixed parsing in gc.set_debug() for
3002 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003003
3004- Fixed refcount problem in instance deallocation that only occurred
3005 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3006
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003007- On Windows, getpythonregpath is now protected against null data in
3008 registry key.
3009
3010- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003011 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003012
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003013
Jeremy Hylton1b618592000-09-26 05:32:36 +00003014Build and platform-specific issues
3015
3016- Better support of GNU Pth via --with-pth configure option.
3017
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003018- Python/C API now properly exposed to dynamically-loaded extension
3019 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003020
3021- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3022 Don't define MS_SYNC to be zero when it is undefined. Added missing
3023 prototypes in posixmodule.c.
3024
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003025- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003026 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003027
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003028- Fix largefile support on older NetBSD systems and OpenBSD by adding
3029 define for TELL64.
3030
3031
3032Tools and other miscellany
3033
3034- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3035
3036- freeze: The modulefinder now works with 2.0 opcodes.
3037
Tim Petersa3a3a032000-11-30 05:22:44 +00003038- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003039 Move hackery of sys.argv until after the Tk instance has been
3040 created, which allows the application-specific Tkinter
3041 initialization to be executed if present; also pass an explicit
3042 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003043
Jeremy Hylton1b618592000-09-26 05:32:36 +00003044
3045What's new in 2.0 beta 1?
3046=========================
3047
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003048Source Incompatibilities
3049------------------------
3050
3051None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3052such as single-argument append(), connect() and bind(), and changes to
3053str(long) and repr(float).
3054
3055
3056Binary Incompatibilities
3057------------------------
3058
3059- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3060with Python 2.0; these extensions will have to be rebuilt for Python
30612.0.
3062
3063- On Windows, attempting to import a third party extension built for
3064Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3065can do about this. Check your PYTHONPATH environment variable!
3066
3067- Python bytecode files (*.pyc and *.pyo) are not compatible between
3068releases.
3069
3070
3071Overview of Changes Since 1.6
3072-----------------------------
3073
3074There are many new modules (including brand new XML support through
3075the xml package, and i18n support through the gettext module); a list
3076of all new modules is included below. Lots of bugs have been fixed.
3077
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003078The process for making major new changes to the language has changed
3079since Python 1.6. Enhancements must now be documented by a Python
3080Enhancement Proposal (PEP) before they can be accepted.
3081
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003082There are several important syntax enhancements, described in more
3083detail below:
3084
3085 - Augmented assignment, e.g. x += 1
3086
3087 - List comprehensions, e.g. [x**2 for x in range(10)]
3088
3089 - Extended import statement, e.g. import Module as Name
3090
3091 - Extended print statement, e.g. print >> file, "Hello"
3092
3093Other important changes:
3094
3095 - Optional collection of cyclical garbage
3096
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003097Python Enhancement Proposal (PEP)
3098---------------------------------
3099
3100PEP stands for Python Enhancement Proposal. A PEP is a design
3101document providing information to the Python community, or describing
3102a new feature for Python. The PEP should provide a concise technical
3103specification of the feature and a rationale for the feature.
3104
3105We intend PEPs to be the primary mechanisms for proposing new
3106features, for collecting community input on an issue, and for
3107documenting the design decisions that have gone into Python. The PEP
3108author is responsible for building consensus within the community and
3109documenting dissenting opinions.
3110
3111The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003112
3113Augmented Assignment
3114--------------------
3115
3116This must have been the most-requested feature of the past years!
3117Eleven new assignment operators were added:
3118
Guido van Rossume905e952000-09-05 12:42:46 +00003119 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003120
3121For example,
3122
3123 A += B
3124
3125is similar to
3126
3127 A = A + B
3128
3129except that A is evaluated only once (relevant when A is something
3130like dict[index].attr).
3131
3132However, if A is a mutable object, A may be modified in place. Thus,
3133if A is a number or a string, A += B has the same effect as A = A+B
3134(except A is only evaluated once); but if a is a list, A += B has the
3135same effect as A.extend(B)!
3136
3137Classes and built-in object types can override the new operators in
3138order to implement the in-place behavior; the not-in-place behavior is
3139used automatically as a fallback when an object doesn't implement the
3140in-place behavior. For classes, the method name is derived from the
3141method name for the corresponding not-in-place operator by inserting
3142an 'i' in front of the name, e.g. __iadd__ implements in-place
3143__add__.
3144
3145Augmented assignment was implemented by Thomas Wouters.
3146
3147
3148List Comprehensions
3149-------------------
3150
3151This is a flexible new notation for lists whose elements are computed
3152from another list (or lists). The simplest form is:
3153
3154 [<expression> for <variable> in <sequence>]
3155
Guido van Rossum56db0952000-09-06 23:34:25 +00003156For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003157This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003158
3159You can also add a condition:
3160
3161 [<expression> for <variable> in <sequence> if <condition>]
3162
3163For example, [w for w in words if w == w.lower()] would yield the list
3164of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003165than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003166
3167You can also have nested for loops and more than one 'if' clause. For
3168example, here's a function that flattens a sequence of sequences::
3169
3170 def flatten(seq):
3171 return [x for subseq in seq for x in subseq]
3172
3173 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3174
3175This prints
3176
3177 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3178
3179List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003180Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003181
3182
3183Extended Import Statement
3184-------------------------
3185
3186Many people have asked for a way to import a module under a different
3187name. This can be accomplished like this:
3188
3189 import foo
3190 bar = foo
3191 del foo
3192
3193but this common idiom gets old quickly. A simple extension of the
3194import statement now allows this to be written as follows:
3195
3196 import foo as bar
3197
3198There's also a variant for 'from ... import':
3199
3200 from foo import bar as spam
3201
3202This also works with packages; e.g. you can write this:
3203
3204 import test.regrtest as regrtest
3205
3206Note that 'as' is not a new keyword -- it is recognized only in this
3207context (this is only possible because the syntax for the import
3208statement doesn't involve expressions).
3209
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003210Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003211
3212
3213Extended Print Statement
3214------------------------
3215
3216Easily the most controversial new feature, this extension to the print
3217statement adds an option to make the output go to a different file
3218than the default sys.stdout.
3219
3220For example, to write an error message to sys.stderr, you can now
3221write:
3222
3223 print >> sys.stderr, "Error: bad dog!"
3224
3225As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003226evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003227
3228 print >> None, "Hello world"
3229
3230is equivalent to
3231
3232 print "Hello world"
3233
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003234Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003235
3236
3237Optional Collection of Cyclical Garbage
3238---------------------------------------
3239
3240Python is now equipped with a garbage collector that can hunt down
3241cyclical references between Python objects. It's no replacement for
3242reference counting; in fact, it depends on the reference counts being
3243correct, and decides that a set of objects belong to a cycle if all
3244their reference counts can be accounted for from their references to
3245each other. This devious scheme was first proposed by Eric Tiedemann,
3246and brought to implementation by Neil Schemenauer.
3247
3248There's a module "gc" that lets you control some parameters of the
3249garbage collection. There's also an option to the configure script
3250that lets you enable or disable the garbage collection. In 2.0b1,
3251it's on by default, so that we (hopefully) can collect decent user
3252experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003253performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003254off by default in the final 2.0 release.
3255
3256
3257Smaller Changes
3258---------------
3259
3260A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3261map(None, seq1, seq2, ...) when the sequences have the same length;
3262i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3263the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003264zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003265
3266sys.version_info is a tuple (major, minor, micro, level, serial).
3267
3268Dictionaries have an odd new method, setdefault(key, default).
3269dict.setdefault(key, default) returns dict[key] if it exists; if not,
3270it sets dict[key] to default and returns that value. Thus:
3271
3272 dict.setdefault(key, []).append(item)
3273
3274does the same work as this common idiom:
3275
3276 if not dict.has_key(key):
3277 dict[key] = []
3278 dict[key].append(item)
3279
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003280There are two new variants of SyntaxError that are raised for
3281indentation-related errors: IndentationError and TabError.
3282
3283Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3284escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003285
3286The limits on the size of expressions and file in Python source code
3287have been raised from 2**16 to 2**32. Previous versions of Python
3288were limited because the maximum argument size the Python VM accepted
3289was 2**16. This limited the size of object constructor expressions,
3290e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3291limit was raised thanks to a patch by Charles Waldman that effectively
3292fixes the problem. It is now much more likely that you will be
3293limited by available memory than by an arbitrary limit in Python.
3294
3295The interpreter's maximum recursion depth can be modified by Python
3296programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3297limit is the maximum number of recursive calls that can be made by
3298Python code. The limit exists to prevent infinite recursion from
3299overflowing the C stack and causing a core dump. The default value is
33001000. The maximum safe value for a particular platform can be found
3301by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003302
3303New Modules and Packages
3304------------------------
3305
3306atexit - for registering functions to be called when Python exits.
3307
3308imputil - Greg Stein's alternative API for writing custom import
3309hooks.
3310
3311pyexpat - an interface to the Expat XML parser, contributed by Paul
3312Prescod.
3313
3314xml - a new package with XML support code organized (so far) in three
3315subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3316would fill a volume. There's a special feature whereby a
3317user-installed package named _xmlplus overrides the standard
3318xmlpackage; this is intended to give the XML SIG a hook to distribute
3319backwards-compatible updates to the standard xml package.
3320
3321webbrowser - a platform-independent API to launch a web browser.
3322
3323
Guido van Rossume905e952000-09-05 12:42:46 +00003324Changed Modules
3325---------------
3326
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003327array -- new methods for array objects: count, extend, index, pop, and
3328remove
3329
3330binascii -- new functions b2a_hex and a2b_hex that convert between
3331binary data and its hex representation
3332
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003333calendar -- Many new functions that support features including control
3334over which day of the week is the first day, returning strings instead
3335of printing them. Also new symbolic constants for days of week,
3336e.g. MONDAY, ..., SUNDAY.
3337
3338cgi -- FieldStorage objects have a getvalue method that works like a
3339dictionary's get method and returns the value attribute of the object.
3340
3341ConfigParser -- The parser object has new methods has_option,
3342remove_section, remove_option, set, and write. They allow the module
3343to be used for writing config files as well as reading them.
3344
3345ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003346optionally support the RFC 959 REST command.
3347
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003348gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003349
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003350httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3351the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003352
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003353locale -- implement getdefaultlocale for Win32 and Macintosh
3354
3355marshal -- no longer dumps core when marshaling deeply nested or
3356recursive data structures
3357
3358os -- new functions isatty, seteuid, setegid, setreuid, setregid
3359
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003360os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3361support under Unix.
3362
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003363os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003364
3365os.path -- fix semantics of os.path.commonprefix
3366
3367smtplib -- support for sending very long messages
3368
3369socket -- new function getfqdn()
3370
3371readline -- new functions to read, write and truncate history files.
3372The readline section of the library reference manual contains an
3373example.
3374
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003375select -- add interface to poll system call
3376
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003377shutil -- new copyfileobj function
3378
3379SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3380HTTP server.
3381
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003382Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003383
3384urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003385e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003386
3387whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003388
3389
3390Obsolete Modules
3391----------------
3392
3393None. However note that 1.6 made a whole slew of modules obsolete:
3394stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3395poly, zmod, strop, util, whatsound.
3396
3397
3398Changed, New, Obsolete Tools
3399----------------------------
3400
Tim Peters8b092332000-09-05 20:15:25 +00003401None.
Guido van Rossume905e952000-09-05 12:42:46 +00003402
3403
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003404C-level Changes
3405---------------
3406
3407Several cleanup jobs were carried out throughout the source code.
3408
3409All C code was converted to ANSI C; we got rid of all uses of the
3410Py_PROTO() macro, which makes the header files a lot more readable.
3411
3412Most of the portability hacks were moved to a new header file,
3413pyport.h; several other new header files were added and some old
3414header files were removed, in an attempt to create a more rational set
3415of header files. (Few of these ever need to be included explicitly;
3416they are all included by Python.h.)
3417
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003418Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003419and Win64, especially for the new Intel Itanium processor. Mick also
3420added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003421
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003422The C APIs to return an object's size have been update to consistently
3423use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3424previous versions, the abstract interfaces used PyXXX_Length and the
3425concrete interfaces used PyXXX_Size. The old names,
3426e.g. PyObject_Length, are still available for backwards compatibility
3427at the API level, but are deprecated.
3428
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003429The PyOS_CheckStack function has been implemented on Windows by
3430Fredrik Lundh. It prevents Python from failing with a stack overflow
3431on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003432
3433The GC changes resulted in creation of two new slots on object,
3434tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003435the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003436
3437The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003438C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003439
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003440PyErr_Format has been updated to automatically calculate the size of
3441the buffer needed to hold the formatted result string. This change
3442prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003443
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003444New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003445
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003446PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3447that are the same as their non-Ex counterparts except they take an
3448extra flag argument that tells them to close the file when done.
3449
3450XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003451
Tim Peters8b092332000-09-05 20:15:25 +00003452
3453Windows Changes
3454---------------
3455
3456New popen2/popen3/peopen4 in os module (see Changed Modules above).
3457
3458os.popen is much more usable on Windows 95 and 98. See Microsoft
3459Knowledge Base article Q150956. The Win9x workaround described there
3460is implemented by the new w9xpopen.exe helper in the root of your
3461Python installation. Note that Python uses this internally; it is not
3462a standalone program.
3463
3464Administrator privileges are no longer required to install Python
3465on Windows NT or Windows 2000. If you have administrator privileges,
3466Python's registry info will be written under HKEY_LOCAL_MACHINE.
3467Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003468under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003469uses of Python, but will prevent some advanced uses from working
3470(for example, running a Python script as an NT service, or possibly
3471from CGI).
3472
3473[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3474installer; instead, it installs the needed Tcl/Tk files directly in the
3475Python directory. If you already have a Tcl/Tk installation, this
3476wastes some disk space (about 4 Megs) but avoids problems with
3477conflicting Tcl/Tk installations, and makes it much easier for Python
3478to ensure that Tcl/Tk can find all its files.
3479
3480[This was new in 1.6] The Windows installer now installs by default in
3481\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3482
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003483
3484Updates to the changes between 1.5.2 and 1.6
3485--------------------------------------------
3486
3487The 1.6 NEWS file can't be changed after the release is done, so here
3488is some late-breaking news:
3489
3490New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3491and changes to getlocale() and setlocale().
3492
3493The new module is now enabled per default.
3494
3495It is not true that the encodings codecs cannot be used for normal
3496strings: the string.encode() (which is also present on 8-bit strings
3497!) allows using them for 8-bit strings too, e.g. to convert files from
3498cp1252 (Windows) to latin-1 or vice-versa.
3499
3500Japanese codecs are available from Tamito KAJIYAMA:
3501http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3502
3503
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003504======================================================================