blob: ff3fdc6b752b0609755236b2b12eb5c03c325bcc [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Fred Draked0ba6362002-05-02 21:28:26 +00009- Deprecated features of xrange objects have been removed as
10 promised. The start, stop, and step attributes and the tolist()
11 method no longer exist. xrange repetition and slicing have been
12 removed.
13
Guido van Rossum7dab2422002-04-26 19:40:56 +000014- New builtin function enumerate(x), from PEP 279. Example:
15 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
16 The argument can be an arbitrary iterable object.
17
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000018- The assert statement no longer tests __debug__ at runtime. This means
19 that assert statements cannot be disabled by assigning a false value
20 to __debug__.
21
Walter Dörwald068325e2002-04-15 13:36:47 +000022- A method zfill() was added to str and unicode, that fills a numeric
23 string to the left with zeros. For example,
24 "+123".zfill(6) -> "+00123".
25
Guido van Rossum862fe3c2002-04-15 12:36:47 +000026- Complex numbers supported divmod() and the // and % operators, but
27 these make no sense. Since this was documented, they're being
28 deprecated now.
29
Guido van Rossum26dd8302002-04-26 20:11:29 +000030- String and unicode methods lstrip(), rstrip() and strip() now take
31 an optional argument that specifies the characters to strip. For
32 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000033
Guido van Rossumc69343b2002-04-12 19:22:48 +000034- Added a new dict method pop(key). This removes and returns the
35 value corresponding to key. [SF patch #539949]
36
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000037- Changed new-style class instantiation so that when C's __new__
38 method returns something that's not a C instance, its __init__ is
39 not called. [SF bug #537450]
40
Guido van Rossum181e41a2002-04-06 00:23:25 +000041- Fixed super() to work correctly with class methods. [SF bug #535444]
42
Guido van Rossum47834462002-04-04 15:21:33 +000043- A new built-in type, bool, has been added, as well as built-in
44 names for its two values, True and False. Comparisons and sundry
45 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000046 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000047 is backward compatible.
48
Guido van Rossum95b62a62002-03-29 01:07:24 +000049- Fixed two bugs reported as SF #535905: under certain conditions,
50 deallocating a deeply nested structure could cause a segfault in the
51 garbage collector, due to interaction with the "trashcan" code;
52 access to the current frame during destruction of a local variable
53 could access a pointer to freed memory.
54
Neil Schemenauer9d50d132002-03-22 17:06:59 +000055- The optional object allocator has been enabled by default.
56
Guido van Rossum8c842552002-03-14 23:05:54 +000057- If you try to pickle an instance of a class that has __slots__ but
58 doesn't define or override __getstate__, a TypeError is now raised.
59 This is done by adding a bozo __getstate__ to the class that always
60 raises TypeError. (Before, this would appear to be pickled, but the
61 state of the slots would be lost.)
62
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000063- PyErr_Display will provide file and line information for all exceptions
64 that have an attribute print_file_and_line, not just SyntaxErrors.
65
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000066- The UTF-8 codec will now encode and decode Unicode surrogates
67 correctly and without raising exceptions for unpaired ones.
68
Neal Norwitz649b7592002-01-01 19:07:13 +000069- file.xreadlines() now raises a ValueError if the file is closed:
70 Previously, an xreadlines object was returned which would raise
71 a ValueError when the xreadlines.next() method was called.
72
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000073- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +000074 An exception will now be raised if more than one argument is used.
75
Tim Petersaf8446f2001-12-21 21:36:50 +000076Extension modules
77
Tim Peters81b92512002-04-29 01:37:32 +000078- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +000079 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +000080 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +000081
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000082- posix.killpg and posix.mknod have been added where available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +000083
Martin v. Löwis2e64c342002-03-27 18:49:02 +000084- The locale module now exposes the C library's gettext interface.
85
Tim Petersfbf74f22002-03-14 19:06:01 +000086- A security hole ("double free") was found in zlib-1.1.3, a popular
87 third party compression library used by some Python modules. The
88 hole was quickly plugged in zlib-1.1.4, and the Windows build of
89 Python now ships with zlib-1.1.4.
90
Martin v. Löwis688357e2002-04-08 21:28:20 +000091- pwd, grp, and resource return enhanced tuples now, with symbolic
92 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +000093
Martin v. Löwis99866332002-03-01 10:27:01 +000094- array.array is now a type object. A new format character
95 'u' indicates Py_UNICODE arrays. For those, .tounicode and
96 .fromunicode methods are available. Arrays now support __iadd__
97 and __imul__.
98
Neal Norwitze790eae2002-01-01 21:14:12 +000099- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000100 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
101 is called.
102
Tim Petersaf8446f2001-12-21 21:36:50 +0000103Library
104
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000105- added degree/radian conversion functions to the math module.
106
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000107- ftplib.retrlines() now tests for callback is None rather than testing
108 for False. Was causing an error when given a callback object which
109 was callable but also returned len() as zero. The change may
110 create new breakage if the caller relied on the undocumented behavior
111 and called with callback set to [] or some other False value not
112 identical to None.
113
Tim Peters46c04e12002-05-05 20:40:00 +0000114- random.gauss() uses a piece of hidden state used by nothing else,
115 and the .seed() and .whseed() methods failed to reset it. In other
116 words, setting the seed didn't completely determine the sequence of
117 results produced by random.gauss(). It does now. Programs repeatedly
118 mixing calls to a seed method with calls to gauss() may see different
119 results now.
120
Fred Drake7f781c92002-05-01 20:33:53 +0000121- The pickle.Pickler class grew a clear_memo() method to mimic that
122 provided by cPickle.Pickler.
123
Tim Peters81b92512002-04-29 01:37:32 +0000124- difflib's SequenceMatcher class now does a dynamic analysis of
125 which elements are so frequent as to constitute noise. For
126 comparing files as sequences of lines, this generally works better
127 than the IS_LINE_JUNK function, and function ndiff's linejunk
128 argument defaults to None now as a result. A happy benefit is
129 that SequenceMatcher may run much faster now when applied
130 to large files with many duplicate lines (for example, C program
131 text with lots of repeated "}" and "return NULL;" lines).
132
Guido van Rossum256705b2002-04-23 13:29:43 +0000133- New Text.dump() method in Tkinter module.
134
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000135- New distutils commands for building packagers were added to
136 support pkgtool on Solaris and swinstall on HP-UX.
137
138- distutils now has a new abstract binary packager base class
139 command/bdist_packager, which simplifies writing packagers.
140 This will hopefully provide the missing bits to encourage
141 people to submit more packagers, e.g. for Debian, FreeBSD
142 and other systems.
143
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000144- The UTF-16, -LE and -BE now raise a NotImplementedError
145 for all calls to .readline(). Previously, they used to just
146 produce garbage or fail with an encoding error -- UTF-16 is
147 a 2-byte encoding and the C lib's line reading APIs don't
148 work well with these.
149
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000150- compileall now supports quiet operation.
151
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000152- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000153 connections.
154
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000155- socket module: the SSL support was broken out of the main
156 _socket module C helper and placed into a new _ssl helper
157 which now gets imported by socket.py if available and working.
158
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000159- encodings package: added aliases for all supported IANA character
160 sets
161
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000162- ftplib: to safeguard the user's privacy, anonymous login will use
163 "anonymous@" as default password, rather than the real user and host
164 name.
165
Fred Drake36736122002-01-10 13:50:31 +0000166- webbrowser: tightened up the command passed to os.system() so that
167 arbitrary shell code can't be executed because a bogus URL was
168 passed in.
169
Tim Peters11bd9942002-02-01 00:52:29 +0000170- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000171 gettext.find an optional all argument. Translations will now fallback
172 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000173
Martin v. Löwis9668b932002-01-12 11:27:42 +0000174- distutils bdist commands now offer a --skip-build option.
175
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000176- warnings.warn now accepts a Warning instance as first argument.
177
Fred Drakefed7e852002-04-04 19:36:15 +0000178- The xml.sax.expatreader.ExpatParser class will no longer create
179 circular references by using itself as the locator that gets passed
180 to the content handler implementation. [SF bug #535474]
181
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000182- The email.Parser.Parser class now properly parses strings regardless
183 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
184 or CRLF). Also, the Header class's constructor default arguments
185 has changed slightly so that an explicit maxlinelen value is always
186 honored.
187
Tim Petersaf8446f2001-12-21 21:36:50 +0000188Tools/Demos
189
Marc-André Lemburg46260092002-04-04 16:17:11 +0000190- freeze.py now produces binaries which can import shared modules,
191 unlike before when this failed due to missing symbol exports in
192 the generated binary.
193
Tim Petersaf8446f2001-12-21 21:36:50 +0000194Build
195
Tim Peters639295f2002-04-21 07:30:30 +0000196- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
197 say how or when to configure it, or how to turn it off.
198
Martin v. Löwis1142de32002-03-29 16:28:31 +0000199- On Unix, a shared libpython2.3.so can be created with --enable-shared.
200
Tim Peters8deda702002-03-30 10:06:07 +0000201- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
202 preprocessor symbols were eliminated. The internal decisions they
203 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000204
Fred Drake7d28b732002-05-02 21:17:00 +0000205- The tools used to build the documentation now work under Cygwin as
206 well as Unix.
207
Tim Petersaf8446f2001-12-21 21:36:50 +0000208C API
209
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000210- Added new macro PySequence_ITEM(o, i) that directly calls
211 sq_item without rechecking that o is a sequence and without
212 adjusting for negative indices.
213
Fred Draked0ba6362002-05-02 21:28:26 +0000214- PyRange_New() now raises ValueError if the fourth argument is not 1.
215 This is part of the removal of deprecated features of the xrange
216 object.
217
Guido van Rossum517c7d42002-04-26 02:49:14 +0000218- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
219 coercion if both arguments have the same type but this type has the
220 CHECKTYPES flag set. This is to better support proxies.
221
Neil Schemenauer9344b142002-04-12 23:00:08 +0000222- The type of tp_free has been changed from "void (*)(PyObject *)" to
223 "void (*)(void *)".
224
225- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
226
Guido van Rossum0986d822002-04-08 01:38:42 +0000227- A type can now inherit its metatype from its base type. Previously,
228 when PyType_Ready() was called, if ob_type was found to be NULL, it
229 was always set to &PyType_Type; now it is set to base->ob_type,
230 where base is tp_base, defaulting to &PyObject_Type.
231
232- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
233
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000234- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000235
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000236- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000237 without going through the buffer API.
238
Martin v. Löwis7198a522002-01-01 19:59:11 +0000239- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
240
Tim Peters10a3bb52001-12-25 19:07:38 +0000241- An old #define of ANY as void has been removed from pyport.h. This
242 hasn't been used since Python's pre-ANSI days, and the #define has
243 been marked as obsolete since then. SF bug 495548 says it created
244 conflicts with other packages, so keeping it around wasn't harmless.
245
Tim Petersaf8446f2001-12-21 21:36:50 +0000246- Because Python's magic number scheme broke on January 1st, we decided
247 to stop Python development. Thanks for all the fish!
248
Tim Petersfb05db22002-03-11 00:24:00 +0000249- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000250 scheme to a new one. See Python/import.c for details.
251
Tim Petersaf8446f2001-12-21 21:36:50 +0000252New platforms
253
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000254- GNU/Hurd is now supported.
255
Tim Petersaf8446f2001-12-21 21:36:50 +0000256Tests
257
258Windows
259
Tim Peters08e72952002-04-16 20:48:01 +0000260- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
261 of that has been fixed in the installer (disabled Wise's "delete in-
262 use files" uninstall option).
263
Guido van Rossum181e41a2002-04-06 00:23:25 +0000264- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
265
Tim Peters33187922002-04-04 20:02:04 +0000266- The installer now installs Start menu shortcuts under (the local
267 equivalent of) "All Users" when doing an Admin install.
268
Tim Petersfb05db22002-03-11 00:24:00 +0000269- file.truncate([newsize]) now works on Windows for all newsize values.
270 It used to fail if newsize didn't fit in 32 bits, reflecting a
271 limitation of MS _chsize (which is no longer used).
272
Tim Petersab034fa2002-02-01 11:27:43 +0000273- os.waitpid() is now implemented for Windows, and can be used to block
274 until a specified process exits. This is similar to, but not exactly
275 the same as, os.waitpid() on POSIX systems. If you're waiting for
276 a specific process whose pid was obtained from one of the spawn()
277 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000278 See the docs for details. The docs were changed to clarify that
279 spawn functions return, and waitpid requires, a process handle on
280 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000281
Tim Peters11bd9942002-02-01 00:52:29 +0000282- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000283 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000284 to a nasty problem: before 2.3, if you got a temp file on Windows, it
285 got wrapped in an object whose close() method first closed the
286 underlying file, then deleted the file. This usually worked fine.
287 However, the spawn family of functions on Windows create (at a low C
288 level) the same set of open files in the spawned process Q as were
289 open in the spawning process P. If a temp file f was among them, then
290 doing f.close() in P first closed P's C-level file handle on f, but Q's
291 C-level file handle on f remained open, so the attempt in P to delete f
292 blew up with a "Permission denied" error (Windows doesn't allow
293 deleting open files). This was surprising, subtle, and difficult to
294 work around.
295
296- The os module now exports all the symbolic constants usable with the
297 low-level os.open() on Windows: the new constants in 2.3 are
298 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
299 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
300 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
301 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
302 (so specify both if you want both; note that neither is useful unless
303 specified with O_CREAT too).
304
Tim Petersaf8446f2001-12-21 21:36:50 +0000305Mac
306
307
Tim Peters909c0912001-12-14 23:16:18 +0000308What's New in Python 2.2 final?
309Release date: 21-Dec-2001
310===============================
311
312Type/class unification and new-style classes
313
Barry Warsaw52acb492001-12-21 20:04:22 +0000314- pickle.py, cPickle: allow pickling instances of new-style classes
315 with a custom metaclass.
316
Tim Peters909c0912001-12-14 23:16:18 +0000317Core and builtins
318
Barry Warsaw52acb492001-12-21 20:04:22 +0000319- weakref proxy object: when comparing, unwrap both arguments if both
320 are proxies.
321
Tim Peters909c0912001-12-14 23:16:18 +0000322Extension modules
323
Barry Warsaw52acb492001-12-21 20:04:22 +0000324- binascii.b2a_base64(): fix a potential buffer overrun when encoding
325 very short strings.
326
327- cPickle: the obscure "fast" mode was suspected of causing stack
328 overflows on the Mac. Hopefully fixed this by setting the recursion
329 limit much smaller. If the limit is too low (it only affects
330 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
331 when compiling cPickle.c (or in pyconfig.h).
332
Tim Peters909c0912001-12-14 23:16:18 +0000333Library
334
Barry Warsaw52acb492001-12-21 20:04:22 +0000335- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
336 close or delete time).
337
338- rfc822.py: fixed a bug where the address '<>' was converted to None
339 instead of an empty string (also fixes the email.Utils module).
340
341- xmlrpclib.py: version 1.0.0; uses precision for doubles.
342
343- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000344 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000345
Tim Peters909c0912001-12-14 23:16:18 +0000346Tools/Demos
347
348Build
349
350C API
351
352New platforms
353
354Tests
355
356Windows
357
Barry Warsaw52acb492001-12-21 20:04:22 +0000358- distutils package: fixed broken Windows installers (bdist_wininst).
359
360- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
361 instances are deleted at process exit time.
362
363- socket.py: prevent mysterious warnings when socket instances are
364 deleted at process exit time.
365
366- posixmodule.c: fix a Windows crash with stat() of a filename ending
367 in backslash.
368
Tim Peters909c0912001-12-14 23:16:18 +0000369Mac
370
Barry Warsaw52acb492001-12-21 20:04:22 +0000371- The Carbon toolbox modules have been upgraded to Universal Headers
372 3.4, and experimental CoreGraphics and CarbonEvents modules have
373 been added. All only for framework-enabled MacOSX.
374
Tim Peters909c0912001-12-14 23:16:18 +0000375
Tim Peters6272dfd2001-12-13 19:34:00 +0000376What's New in Python 2.2c1?
377Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000378===========================
379
380Type/class unification and new-style classes
381
Barry Warsaw06557452001-12-14 20:47:12 +0000382- Guido's tutorial introduction to the new type/class features has
383 been extensively updated. See
384
385 http://www.python.org/2.2/descrintro.html
386
387 That remains the primary documentation in this area.
388
Guido van Rossum33bab012001-12-05 22:45:48 +0000389- Fixed a leak: instance variables declared with __slots__ were never
390 deleted!
391
Guido van Rossum4b800852001-12-03 00:54:52 +0000392- The "delete attribute" method of descriptor objects is called
393 __delete__, not __del__. In previous releases, it was mistakenly
394 called __del__, which created an unfortunate overloading condition
395 with finalizers. (The "get attribute" and "set attribute" methods
396 are still called __get__ and __set__, respectively.)
397
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000398- Some subtle issues with the super built-in were fixed:
399
400 (a) When super itself is subclassed, its __get__ method would still
401 return an instance of the base class (i.e., of super).
402
403 (b) super(C, C()).__class__ would return C rather than super. This
404 is confusing. To fix this, I decided to change the semantics of
405 super so that it only applies to code attributes, not to data
406 attributes. After all, overriding data attributes is not
407 supported anyway.
408
409 (c) The __get__ method didn't check whether the argument was an
410 instance of the type used in creation of the super instance.
411
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000412- Previously, hash() of an instance of a subclass of a mutable type
413 (list or dictionary) would return some value, rather than raising
414 TypeError. This has been fixed. Also, directly calling
415 dict.__hash__ and list.__hash__ now raises the same TypeError
416 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000417
Guido van Rossumd331cb52001-12-05 19:46:42 +0000418- New-style objects now support deleting their __dict__. This is for
419 all intents and purposes equivalent to assigning a brand new empty
420 dictionary, but saves space if the object is not used further.
421
Tim Petersb3c9af12001-11-17 00:21:57 +0000422Core and builtins
423
Tim Peters3caca232001-12-06 06:23:26 +0000424- -Qnew now works as documented in PEP 238: when -Qnew is passed on
425 the command line, all occurrences of "/" use true division instead
426 of classic division. See the PEP for details. Note that "all"
427 means all instances in library and 3rd-party modules, as well as in
428 your own code. As the PEP says, -Qnew is intended for use only in
429 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000430 Note that test_coercion.py in the standard Python test suite fails
431 under -Qnew; this is expected, and won't be repaired until true
432 division becomes the default (in the meantime, test_coercion is
433 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000434
Fred Drake6c01e252001-12-14 17:08:12 +0000435- complex() now only allows the first argument to be a string
436 argument, and raises TypeError if either the second arg is a string
437 or if the second arg is specified when the first is a string.
438
Tim Petersb3c9af12001-11-17 00:21:57 +0000439Extension modules
440
Martin v. Löwis560da622001-11-24 09:24:51 +0000441- gc.get_referents was renamed to gc.get_referrers.
442
Tim Petersb3c9af12001-11-17 00:21:57 +0000443Library
444
Tim Peters25059d32001-12-07 20:35:43 +0000445- Functions in the os.spawn() family now release the global interpreter
446 lock around calling the platform spawn. They should always have done
447 this, but did not before 2.2c1. Multithreaded programs calling
448 an os.spawn function with P_WAIT will no longer block all Python threads
449 until the spawned program completes. It's possible that some programs
450 relies on blocking, although more likely by accident than by design.
451
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000452- webbrowser defaults to netscape.exe on OS/2 now.
453
Martin v. Löwis652e1912001-11-25 14:50:56 +0000454- Tix.ResizeHandle exposes detach_widget, hide, and show.
455
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000456- The charset alias windows_1252 has been added.
457
Barry Warsaw06557452001-12-14 20:47:12 +0000458- types.StringTypes is a tuple containing the defined string types;
459 usually this will be (str, unicode), but if Python was compiled
460 without Unicode support it will be just (str,).
461
462- The pulldom and minidom modules were synchronized to PyXML.
463
Tim Petersb3c9af12001-11-17 00:21:57 +0000464Tools/Demos
465
Barry Warsaw06557452001-12-14 20:47:12 +0000466- A new script called Tools/scripts/google.py was added, which fires
467 off a search on Google.
468
Tim Petersb3c9af12001-11-17 00:21:57 +0000469Build
470
Barry Warsaw06557452001-12-14 20:47:12 +0000471- Note that release builds of Python should arrange to define the
472 preprocessor symbol NDEBUG on the command line (or equivalent).
473 In the 2.2 pre-release series we tried to define this by magic in
474 Python.h instead, but it proved to cause problems for extension
475 authors. The Unix, Windows and Mac builds now all define NDEBUG in
476 release builds via cmdline (or equivalent) instead. Ports to
477 other platforms should do likewise.
478
Jack Jansen1999ef42001-12-06 21:47:20 +0000479- It is no longer necessary to use --with-suffix when building on a
480 case-insensitive file system (such as Mac OS X HFS+). In the build
481 directory an extension is used, but not in the installed python.
482
Tim Petersb3c9af12001-11-17 00:21:57 +0000483C API
484
Tim Petersf582b822001-12-11 18:51:08 +0000485- New function PyDict_MergeFromSeq2() exposes the builtin dict
486 constructor's logic for updating a dictionary from an iterable object
487 producing key-value pairs.
488
Tim Peterscffed4b2001-11-29 03:26:37 +0000489- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000490 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000491 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
492 dump core in some bad cases. This has been repaired. As a result,
493 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
494 previously went unchallenged.
495
Tim Petersb3c9af12001-11-17 00:21:57 +0000496New platforms
497
498Tests
499
500Windows
501
502Mac
503
Jack Jansenffa260f2001-12-06 21:14:00 +0000504- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
505 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000506
Barry Warsaw06557452001-12-14 20:47:12 +0000507- Changed logic for finding python home in Mac OS X framework Pythons.
508 Now sys.executable points to the executable again, in stead of to
509 the shared library. The latter is used only for locating the python
510 home.
511
512
Tim Peters84362bc2001-10-19 17:55:30 +0000513What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000514Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000515===========================
516
517Type/class unification and new-style classes
518
Guido van Rossum3d27df02001-11-15 20:27:54 +0000519- Multiple inheritance mixing new-style and classic classes in the
520 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000521
522 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000523 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000524
525 The MRO (method resolution order) for each base class is respected
526 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000527 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000528 This needs to be documented.
529
Tim Petersa427a2b2001-10-29 22:25:45 +0000530- The new builtin dictionary() constructor, and dictionary type, have
531 been renamed to dict. This reflects a decade of common usage.
532
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000533- dict() now accepts an iterable object producing 2-sequences. For
534 example, dict(d.items()) == d for any dictionary d. The argument,
535 and the elements of the argument, can be any iterable objects.
536
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000537- New-style classes can now have a __del__ method, which is called
538 when the instance is deleted (just like for classic classes).
539
Guido van Rossum12d955c2001-10-26 14:56:06 +0000540- Assignment to object.__dict__ is now possible, for objects that are
541 instances of new-style classes that have a __dict__ (unless the base
542 class forbids it).
543
Guido van Rossumc8e56452001-10-22 00:43:43 +0000544- Methods of built-in types now properly check for keyword arguments
545 (formerly these were silently ignored). The only built-in methods
546 that take keyword arguments are __call__, __init__ and __new__.
547
Guido van Rossum86443212001-10-27 22:28:54 +0000548- The socket function has been converted to a type; see below.
549
Tim Peters84362bc2001-10-19 17:55:30 +0000550Core and builtins
551
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000552- Assignment to __debug__ raises SyntaxError at compile-time. This
553 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000554 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000555
Guido van Rossum12d955c2001-10-26 14:56:06 +0000556- Clarified the error messages for unsupported operands to an operator
557 (like 1 + '').
558
Tim Peters84362bc2001-10-19 17:55:30 +0000559Extension modules
560
Tim Peters5ebfd362001-11-13 23:11:19 +0000561- mmap has a new keyword argument, "access", allowing a uniform way for
562 both Windows and Unix users to create read-only, write-through and
563 copy-on-write memory mappings. This was previously possible only on
564 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000565 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000566 platforms. Thanks to Jay T Miller for repairing this!
567
Tim Peters169ded02001-11-03 19:57:21 +0000568- By default, the gc.garbage list now contains only those instances in
569 unreachable cycles that have __del__ methods; in 2.1 it contained all
570 instances in unreachable cycles. "Instances" here has been generalized
571 to include instances of both new-style and old-style classes.
572
Guido van Rossum12d955c2001-10-26 14:56:06 +0000573- The socket module defines a new method for socket objects,
574 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000575 send() until all data has been sent. Also, the socket function has
576 been converted to a subclassable type, like list and tuple (etc.)
577 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000578
579- Various bugfixes to the curses module. There is now a test suite
580 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000581
Guido van Rossum692adf12001-10-30 03:03:03 +0000582- binascii.b2a_base64 no longer places an arbitrary restriction of 57
583 bytes on its input.
584
Tim Peters84362bc2001-10-19 17:55:30 +0000585Library
586
Tim Peters5ebfd362001-11-13 23:11:19 +0000587- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000588 convenience function.
589
Tim Peters75335872001-11-03 19:35:43 +0000590- Symbolic group names in regular expressions must be unique. For
591 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
592 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000593 Python 2.2 detects this error at regexp compilation time;
594 previously, the error went undetected, and results were
595 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
596 pattern.subn() methods have been rewritten in C. Also, an
597 experimental function/method finditer() has been added, which works
598 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000599
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000600- Tix exposes more commands through the classes DirSelectBox,
601 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
602 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
603 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
604
Tim Peters98791af2001-10-23 01:59:54 +0000605- Traceback objects are now scanned by cyclic garbage collection, so
606 cycles created by casual use of sys.exc_info() no longer cause
607 permanent memory leaks (provided garbage collection is enabled).
608
Guido van Rossum49192142001-10-24 20:51:44 +0000609- os.extsep -- a new variable needed by the RISCOS support. It is the
610 separator used by extensions, and is '.' on all platforms except
611 RISCOS, where it is '/'. There is no need to use this variable
612 unless you have a masochistic desire to port your code to RISCOS.
613
Barry Warsaw012852b2001-11-16 16:17:27 +0000614- mimetypes.py has optional support for non-standard, but commonly
615 found types. guess_type() and guess_extension() now accept an
616 optional `strict' flag, defaulting to true, which controls whether
617 recognize non-standard types or not. A few non-standard types we
618 know about have been added. Also, when run as a script, there are
619 new -l and -e options.
620
621- statcache is now deprecated.
622
623- email.Utils.formatdate() now produces the preferred RFC 2822 style
624 dates with numeric timezones (it used to produce obsolete dates
625 hard coded to "GMT" timezone). An optional `localtime' flag is
626 added to produce dates in the local timezone, with daylight savings
627 time properly taken into account.
628
629- In pickle and cPickle, instead of masking errors in load() by
630 transforming them into SystemError, we let the original exception
631 propagate out. Also, implement support for __safe_for_unpickling__
632 in pickle, as it already was supported in cPickle.
633
Tim Peters84362bc2001-10-19 17:55:30 +0000634Tools/Demos
635
636Build
637
Barry Warsaw012852b2001-11-16 16:17:27 +0000638- The dbm module is built using libdb1 if available. The bsddb module
639 is built with libdb3 if available.
640
641- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
642
Tim Peters84362bc2001-10-19 17:55:30 +0000643C API
644
Tim Peters1fc240e2001-10-26 05:06:50 +0000645- New function PySequence_Fast_GET_SIZE() returns the size of a non-
646 NULL result from PySequence_Fast(), more quickly than calling
647 PySequence_Size().
648
Barry Warsaw012852b2001-11-16 16:17:27 +0000649- New argument unpacking function PyArg_UnpackTuple() added.
650
651- New functions PyObject_CallFunctionObjArgs() and
652 PyObject_CallMethodObjArgs() have been added to make it more
653 convenient and efficient to call functions and methods from C.
654
655- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
656 possible that this will propagate errors it didn't before.
657
658- New function PyObject_CheckReadBuffer(), which returns true if its
659 argument supports the single-segment readable buffer interface.
660
Tim Peters84362bc2001-10-19 17:55:30 +0000661New platforms
662
Guido van Rossum86443212001-10-27 22:28:54 +0000663- We've finally confirmed that this release builds on HP-UX 11.00,
664 *with* threads, and passes the test suite.
665
Tim Peters7a33d8b2001-11-05 02:51:07 +0000666- Thanks to a series of patches from Michael Muller, Python may build
667 again under OS/2 Visual Age C++.
668
Guido van Rossum49192142001-10-24 20:51:44 +0000669- Updated RISCOS port by Dietmar Schwertberger.
670
Tim Peters84362bc2001-10-19 17:55:30 +0000671Tests
672
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000673- Added a test script for the curses module. It isn't run automatically;
674 regrtest.py must be run with '-u curses' to enable it.
675
Tim Peters84362bc2001-10-19 17:55:30 +0000676Windows
677
Barry Warsaw012852b2001-11-16 16:17:27 +0000678Mac
679
680- PythonScript has been moved to unsupported and is slated to be
681 removed completely in the next release.
682
683- It should now be possible to build applets that work on both OS9 and
684 OSX.
685
686- The core is now linked with CoreServices not Carbon; as a side
687 result, default 8bit encoding on OSX is now ASCII.
688
689- Python should now build on OSX 10.1.1
690
Tim Peters84362bc2001-10-19 17:55:30 +0000691
Tim Petersabf925f2001-09-28 21:53:42 +0000692What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000693Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000694===========================
695
696Type/class unification and new-style classes
697
Guido van Rossum687ae002001-10-15 22:03:32 +0000698- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000699 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000700 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000701 remains: the __dict__ of a new-style class is a read-only proxy; you
702 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000703 __defined__ attribute of new-style types no longer exists, for lack
704 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000705 future a __cache__ may be resurrected with a similar function, if I
706 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000707
Tim Peters1c9ca872001-10-04 06:43:12 +0000708- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
709 always returned None, even when there was a class docstring).
710
711- doctest now finds and runs docstrings attached to new-style classes,
712 class methods, static methods, and properties.
713
Guido van Rossum9074ef62001-10-16 21:34:49 +0000714Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000715
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000716- A very subtle syntactical pitfall in list comprehensions was fixed.
717 For example: [a+b for a in 'abc', for b in 'def']. The comma in
718 this example is a mistake. Previously, this would silently let 'a'
719 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
720 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
721 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
722 Note that [a for a in <singleton>] is a convoluted way to say
723 [<singleton>] anyway, so it's not like any expressiveness is lost.
724
Guido van Rossum9074ef62001-10-16 21:34:49 +0000725- getattr(obj, name, default) now only catches AttributeError, as
726 documented, rather than returning the default value for all
727 exceptions (which could mask bugs in a __getattr__ hook, for
728 example).
729
Fred Drakecb7a6b52001-10-22 18:41:51 +0000730- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000731 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000732 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000733 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000734
Guido van Rossum1c486092001-10-19 02:05:35 +0000735- unicode(obj) now behaves more like str(obj), accepting arbitrary
736 objects, and calling a __unicode__ method if it exists.
737 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000738 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000739
Barry Warsawf6fb1712001-10-19 05:35:40 +0000740- isinstance() now allows any object as the first argument and a
741 class, a type or something with a __bases__ tuple attribute for the
742 second argument. The second argument may also be a tuple of a
743 class, type, or something with __bases__, in which case isinstance()
744 will return true if the first argument is an instance of any of the
745 things contained in the second argument tuple. E.g.
746
747 isinstance(x, (A, B))
748
749 returns true if x is an instance of A or B.
750
Guido van Rossum9074ef62001-10-16 21:34:49 +0000751Extension modules
752
753- thread.start_new_thread() now returns the thread ID (previously None).
754
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000755- binascii has now two quopri support functions, a2b_qp and b2a_qp.
756
Guido van Rossumc524d952001-10-19 01:31:59 +0000757- readline now supports setting the startup_hook and the
758 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000759
Guido van Rossumc524d952001-10-19 01:31:59 +0000760- os and posix supports chroot(), setgroups() and unsetenv() where
761 available. The stat(), fstat(), statvfs() and fstatvfs() functions
762 now return "pseudo-sequences" -- the various fields can now be
763 accessed as attributes (e.g. os.stat("/").st_mtime) but for
764 backwards compatibility they also behave as a fixed-length sequence.
765 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000766 attributes.
767
768- time: localtime(), gmtime() and strptime() now return a
769 pseudo-sequence similar to the os.stat() return value, with
770 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000771
Guido van Rossum9074ef62001-10-16 21:34:49 +0000772- Decompression objects in the zlib module now accept an optional
773 second parameter to decompress() that specifies the maximum amount
774 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000775
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000776- optional SSL support in the socket module now exports OpenSSL
777 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
778 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000779 automatically seed its PRNG. Also, the keyfile and certfile
780 arguments to socket.ssl() are now optional.
781
782- posixmodule (and by extension, the os module on POSIX platforms) now
783 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000784
Guido van Rossum9074ef62001-10-16 21:34:49 +0000785Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000786
Tim Peters7402f792001-10-02 03:53:41 +0000787- doctest now excludes functions and classes not defined by the module
788 being tested, thanks to Tim Hochberg.
789
Fred Drakecb7a6b52001-10-22 18:41:51 +0000790- HotShot, a new profiler implemented using a C-based callback, has
791 been added. This substantially reduces the overhead of profiling,
792 but it is still quite preliminary. Support modules and
793 documentation will be added in upcoming releases (before 2.2 final).
794
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000795- profile now produces correct output in situations where an exception
796 raised in Python is cleared by C code (e.g. hasattr()). This used
797 to cause wrong output, including spurious claims of recursive
798 functions and attribution of time spent to the wrong function.
799
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000800 The code and documentation for the derived OldProfile and HotProfile
801 profiling classes was removed. The code hasn't worked for years (if
802 you tried to use them, they raised exceptions). OldProfile
803 intended to reproduce the behavior of the profiler Python used more
804 than 7 years ago, and isn't interesting anymore. HotProfile intended
805 to provide a faster profiler (but producing less information), and
806 that's a worthy goal we intend to meet via a different approach (but
807 without losing information).
808
Tim Peterscce092d2001-10-09 05:31:56 +0000809- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000810 a much better system-specific calibration constant. The constant can
811 now be specified in an instance constructor, or as a Profile class or
812 instance variable, instead of by editing profile.py's source code.
813 Calibration must still be done manually (see the docs for the profile
814 module).
815
816 Note that Profile.calibrate() must be overriden by subclasses.
817 Improving the accuracy required exploiting detailed knowledge of
818 profiler internals; the earlier method abstracted away the details
819 and measured a simplified model instead, but consequently computed
820 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000821
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000822- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000823 which indicates whether output is intended for the header 'Q'
824 encoding.
825
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000826- The SocketServer.ThreadingMixIn class now closes the request after
827 finish_request() returns. (Not when it errors out though.)
828
Barry Warsawf6fb1712001-10-19 05:35:40 +0000829- The nntplib module's NNTP.body() method has grown a `file' argument
830 to allow saving the message body to a file.
831
832- The email package has added a class email.Parser.HeaderParser which
833 only parses headers and does not recurse into the message's body.
834 Also, the module/class MIMEAudio has been added for representing
835 audio data (contributed by Anthony Baxter).
836
837- ftplib should be able to handle files > 2GB.
838
839- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
840 ON, and OFF.
841
Fred Drakecb7a6b52001-10-22 18:41:51 +0000842- xml.dom.minidom NodeList objects now support the length attribute
843 and item() method as required by the DOM specifications.
844
Guido van Rossumed554f62001-10-02 23:15:37 +0000845Tools/Demos
846
847- Demo/dns was removed. It no longer serves any purpose; a package
848 derived from it is now maintained by Anthony Baxter, see
849 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000850
Barry Warsawf6fb1712001-10-19 05:35:40 +0000851- The freeze tool has been made more robust, and two new options have
852 been added: -X and -E.
853
Tim Petersabf925f2001-09-28 21:53:42 +0000854Build
855
Barry Warsawf6fb1712001-10-19 05:35:40 +0000856- configure will use CXX in LINKCC if CXX is used to build main() and
857 the system requires to link a C++ main using the C++ compiler.
858
Tim Petersabf925f2001-09-28 21:53:42 +0000859C API
860
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000861- The documentation for the tp_compare slot is updated to require that
862 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
863 not correct. This is not yet enforced but will be enforced in
864 Python 2.3; even later, we may use -2 to indicate errors and +2 for
865 "NotImplemented". Right now, -1 should be used for an error return.
866
Tim Petersd38b1c72001-09-30 05:09:37 +0000867- PyLong_AsLongLong() now accepts int (as well as long) arguments.
868 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
869 as long) arguments.
870
Guido van Rossum3c288632001-10-16 21:13:49 +0000871- PyThread_start_new_thread() now returns a long int giving the thread
872 ID, if one can be calculated; it returns -1 for error, 0 if no
873 thread ID is calculated (this is an incompatible change, but only
874 the thread module used this API). This code has only really been
875 tested on Linux and Windows; other platforms please beware (and
876 report any bugs or strange behavior).
877
Guido van Rossum1c486092001-10-19 02:05:35 +0000878- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
879 input.
880
Tim Petersabf925f2001-09-28 21:53:42 +0000881New platforms
882
883Tests
884
885Windows
886
Tim Peters04cf1d32001-10-09 22:39:40 +0000887- Installer: If you install IDLE, and don't disable file-extension
888 registration, a new "Edit with IDLE" context (right-click) menu entry
889 is created for .py and .pyw files.
890
Tim Peters1ce3cf72001-10-01 17:58:40 +0000891- The signal module now supports SIGBREAK on Windows, thanks to Steven
892 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
893 action remains to call Win32 ExitProcess(). This can be changed via
894 signal.signal(). For example:
895
896 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
897 # (SIGINT) behavior.
898 import signal
899 signal.signal(signal.SIGBREAK,
900 signal.default_int_handler)
901
902 try:
903 while 1:
904 pass
905 except KeyboardInterrupt:
906 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
907 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
908 # program without the possibility for any Python-level cleanup).
909 print "Clean exit"
910
Tim Petersabf925f2001-09-28 21:53:42 +0000911
Tim Petersb07352e2001-09-08 01:25:47 +0000912What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000913Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000914===========================
915
Guido van Rossum808eea72001-09-25 04:15:41 +0000916Type/class unification and new-style classes
917
918- pydoc and inspect are now aware of new-style classes;
919 e.g. help(list) at the interactive prompt now shows proper
920 documentation for all operations on list objects.
921
922- Applications using Jim Fulton's ExtensionClass module can now safely
923 be used with Python 2.2. In particular, Zope 2.4.1 now works with
924 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
925 examples also work again. It is hoped that Gtk and Boost also work
926 with 2.2a4 and beyond. (If you can confirm this, please write
927 webmaster@python.org; if there are still problems, please open a bug
928 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000929
Tim Peters66c1a522001-09-24 21:17:50 +0000930- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000931 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +0000932 in the constructed property object. fget, fset and fdel weren't
933 discoverable from Python in 2.2a3. __doc__ is new, and allows to
934 associate a docstring with a property.
935
Guido van Rossum808eea72001-09-25 04:15:41 +0000936- Comparison overloading is now more completely implemented. For
937 example, a str subclass instance can properly be compared to a str
938 instance, and it can properly overload comparison. Ditto for most
939 other built-in object types.
940
941- The repr() of new-style classes has changed; instead of <type
942 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
943 *except* for built-in types, which are still rendered as <type
944 'Foo'> (to avoid upsetting existing code that might parse or
945 otherwise rely on repr() of certain type objects).
946
947- The repr() of new-style objects is now always <Foo object at XXX>;
948 previously, it was sometimes <Foo instance at XXX>.
949
950- For new-style classes, what was previously called __getattr__ is now
951 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000952 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000953 one in classic classes is defined which is called only if regular
954 attribute access raises AttributeError; to catch *all* attribute
955 access, you can use __getattribute__ (for new-style classes). If
956 both are defined, __getattribute__ is called first, and if it raises
957 AttributeError, __getattr__ is called.
958
959- The __class__ attribute of new-style objects can be assigned to.
960 The new class must have the same C-level object layout as the old
961 class.
962
963- The builtin file type can be subclassed now. In the usual pattern,
964 "file" is the name of the builtin type, and file() is a new builtin
965 constructor, with the same signature as the builtin open() function.
966 file() is now the preferred way to open a file.
967
968- Previously, __new__ would only see sequential arguments passed to
969 the type in a constructor call; __init__ would see both sequential
970 and keyword arguments. This made no sense whatsoever any more, so
971 now both __new__ and __init__ see all arguments.
972
973- Previously, hash() applied to an instance of a subclass of str or
974 unicode always returned 0. This has been repaired.
975
976- Previously, an operation on an instance of a subclass of an
977 immutable type (int, long, float, complex, tuple, str, unicode),
978 where the subtype didn't override the operation (and so the
979 operation was handled by the builtin type), could return that
980 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000981 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +0000982 with the same value as s.
983
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000984- Provisional support for pickling new-style objects has been added.
985
Guido van Rossum808eea72001-09-25 04:15:41 +0000986Core
987
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000988- file.writelines() now accepts any iterable object producing strings.
989
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000990- PyUnicode_FromEncodedObject() now works very much like
991 PyObject_Str(obj) in that it tries to use __str__/tp_str
992 on the object if the object is not a string or buffer. This
993 makes unicode() behave like str() when applied to non-string/buffer
994 objects.
995
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000996- PyFile_WriteObject now passes Unicode objects to the file's write
997 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000998 of a print statement must support Unicode objects, i.e. they must
999 at least convert them into ASCII strings.
1000
Guido van Rossum624c8af2001-09-18 15:21:04 +00001001- Thread scheduling on Solaris should be improved; it is no longer
1002 necessary to insert a small sleep at the start of a thread in order
1003 to let other runnable threads be scheduled.
1004
Tim Petersb07352e2001-09-08 01:25:47 +00001005Library
1006
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001007- StringIO.StringIO instances and cStringIO.StringIO instances support
1008 read character buffer compatible objects for their .write() methods.
1009 These objects are converted to strings and then handled as such
1010 by the instances.
1011
Barry Warsaw2f600732001-09-24 04:28:10 +00001012- The "email" package has been added. This is basically a port of the
1013 mimelib package <http://sf.net/projects/mimelib> with API changes
1014 and some implementations updated to use iterators and generators.
1015
Tim Peters8a9c2842001-09-22 21:30:22 +00001016- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1017 restores the ability of Tools/scripts/ndiff.py to start producing output
1018 before the entire comparison is complete.
1019
Barry Warsaw58b072d2001-09-22 04:44:21 +00001020- StringIO.StringIO instances and cStringIO.StringIO instances support
1021 iteration just like file objects (i.e. their .readline() method is
1022 called for each iteration until it returns an empty string).
1023
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001024- The codecs module has grown four new helper APIs to access
1025 builtin codecs: getencoder(), getdecoder(), getreader(),
1026 getwriter().
1027
Guido van Rossum624c8af2001-09-18 15:21:04 +00001028- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1029 simplifies writing XML RPC servers.
1030
Barry Warsaw647d5e82001-09-28 17:01:02 +00001031- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001032 after interpretation of symbolic links. On non-Unix systems, this
1033 is an alias for os.path.abspath().
1034
Tim Peters16a77ad2001-09-08 04:00:12 +00001035- operator.indexOf() (PySequence_Index() in the C API) now works with any
1036 iterable object.
1037
Guido van Rossum624c8af2001-09-18 15:21:04 +00001038- smtplib now supports various authentication and security features of
1039 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001040
Guido van Rossum624c8af2001-09-18 15:21:04 +00001041- hmac: a new module implementing keyed hashing for message
1042 authentication.
1043
1044- mimetypes now recognizes more extensions and file types. At the
1045 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001046
Guido van Rossum624c8af2001-09-18 15:21:04 +00001047- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001048 Python 2.2 bytecode generation. It has also been promoted from a
1049 Tool to a standard library package. (Tools/compiler still exists as
1050 a sample driver.)
1051
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001052Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001053
Tim Petersb07352e2001-09-08 01:25:47 +00001054Build
1055
Guido van Rossum624c8af2001-09-18 15:21:04 +00001056- Large file support (LFS) is now automatic when the platform supports
1057 it; no more manual configuration tweaks are needed. On Linux, at
1058 least, it's possible to have a system whose C library supports large
1059 files but whose kernel doesn't; in this case, large file support is
1060 still enabled but doesn't do you any good unless you upgrade your
1061 kernel or share your Python executable with another system whose
1062 kernel has large file support.
1063
1064- The configure script now supplies plausible defaults in a
1065 cross-compilation environment. This doesn't mean that the supplied
1066 values are always correct, or that cross-compilation now works
1067 flawlessly -- but it's a first step (and it shuts up most of
1068 autoconf's warnings about AC_TRY_RUN).
1069
1070- The Unix build is now a bit less chatty, courtesy of the parser
1071 generator. The build is completely silent (except for errors) when
1072 using "make -s", thanks to a -q option to setup.py.
1073
Tim Petersb07352e2001-09-08 01:25:47 +00001074C API
1075
Guido van Rossum624c8af2001-09-18 15:21:04 +00001076- The "structmember" API now supports some new flag bits to deny read
1077 and/or write access to attributes in restricted execution mode.
1078
Tim Petersb07352e2001-09-08 01:25:47 +00001079New platforms
1080
Guido van Rossum624c8af2001-09-18 15:21:04 +00001081- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1082 (http://familiar.handhelds.org).
1083
Tim Petersb07352e2001-09-08 01:25:47 +00001084Tests
1085
Tim Peters8a9c2842001-09-22 21:30:22 +00001086- The "classic" standard tests, which work by comparing stdout to
1087 an expected-output file under Lib/test/output/, no longer stop at
1088 the first mismatch. Instead the test is run to completion, and a
1089 variant of ndiff-style comparison is used to report all differences.
1090 This is much easier to understand than the previous style of reporting.
1091
1092- The unittest-based standard tests now use regrtest's test_main()
1093 convention, instead of running as a side-effect of merely being
1094 imported. This allows these tests to be run in more natural and
1095 flexible ways as unittests, outside the regrtest framework.
1096
1097- regrtest.py is much better integrated with unittest and doctest now,
1098 especially in regard to reporting errors.
1099
Tim Petersb07352e2001-09-08 01:25:47 +00001100Windows
1101
Guido van Rossum624c8af2001-09-18 15:21:04 +00001102- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001103 that support it (NTFS under Windows 2000). See "What's New in
1104 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001105
Tim Petersb07352e2001-09-08 01:25:47 +00001106
Tim Petersedc99312001-08-22 21:36:50 +00001107What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001108Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001109===========================
1110
1111Core
1112
Tim Peters9fffa3e2001-09-04 05:14:19 +00001113- Conversion of long to float now raises OverflowError if the long is too
1114 big to represent as a C double.
1115
Tim Peters32f453e2001-09-03 08:35:41 +00001116- The 3-argument builtin pow() no longer allows a third non-None argument
1117 if either of the first two arguments is a float, or if both are of
1118 integer types and the second argument is negative (in which latter case
1119 the arguments are converted to float, so this is really the same
1120 restriction).
1121
Tim Peters5d2b77c2001-09-03 05:47:38 +00001122- The builtin dir() now returns more information, and sometimes much
1123 more, generally naming all attributes of an object, and all attributes
1124 reachable from the object via its class, and from its class's base
1125 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1126 an empty list. In 2.2a3,
1127
1128 >>> dir([])
1129 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1130 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1131 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1132 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1133 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1134 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1135 'reverse', 'sort']
1136
1137 dir(module) continues to return only the module's attributes, though.
1138
Tim Petersbdee63f2001-09-02 03:40:59 +00001139- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001140 than raising OverflowError. This is a partial implementation of PEP
1141 237. You can use -Wdefault::OverflowWarning to enable a warning for
1142 this situation, and -Werror::OverflowWarning to revert to the old
1143 OverflowError exception.
1144
Guido van Rossum61c345f2001-09-04 03:26:15 +00001145- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001146 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001147 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1148 -Qold, meaning the / operator has its classic meaning and no
1149 warnings are issued. Using -Qwarn issues a run-time warning about
1150 all uses of classic division for int and long arguments; -Qwarnall
1151 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001152 (for use with fixdiv.py).
1153 [Note: the remainder of this paragraph (preserved below) became
1154 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1155 <obsolete>
1156 Using -Qnew is questionable; it turns on new division by default, but
1157 only in the __main__ module. You can usefully combine -Qwarn or
1158 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1159 warns about classic division everywhere else.
1160 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001161
Tim Petersbdee63f2001-09-02 03:40:59 +00001162- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001163 long, float, str, unicode, and tuple. (The types complex, list and
1164 dictionary can also be subclassed; this was introduced earlier.)
1165 Note that restrictions apply when subclassing immutable built-in
1166 types: you can only affect the value of the instance by overloading
1167 __new__. You can add mutable attributes, and the subclass instances
1168 will have a __dict__ attribute, but you cannot change the "value"
1169 (as implemented by the base class) of an immutable subclass instance
1170 once it is created.
1171
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001172- The dictionary constructor now takes an optional argument, a
1173 mapping-like object, and initializes the dictionary from its
1174 (key, value) pairs.
1175
Tim Petersbdee63f2001-09-02 03:40:59 +00001176- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001177 "cooperative super calls" in a multiple inheritance setting. For an
1178 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1179
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001180- A new built-in type, property, has been added. This enables the
1181 creation of "properties". These are attributes implemented by
1182 getter and setter functions (or only one of these for read-only or
1183 write-only attributes), without the need to override __getattr__.
1184 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001185
Tim Petersbdee63f2001-09-02 03:40:59 +00001186- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001187 liberalized, to allow leading zeroes. Examples of literals now
1188 legal that were SyntaxErrors before:
1189
1190 00.0 0e3 0100j 07.5 00000000000000000008.
1191
Tim Petersbdee63f2001-09-02 03:40:59 +00001192- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001193 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1194
Tim Petersedc99312001-08-22 21:36:50 +00001195Library
1196
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001197- telnetlib includes symbolic names for the options, and support for
1198 setting an option negotiation callback.
1199
Tim Petersa40c7932001-09-05 22:36:56 +00001200- The new C standard no longer requires that math libraries set errno to
1201 ERANGE on overflow. For platform libraries that exploit this new
1202 freedom, Python's overflow-checking was wholly broken. A new overflow-
1203 checking scheme attempts to repair that, but may not be reliable on all
1204 platforms (C doesn't seem to provide anything both useful and portable
1205 in this area anymore).
1206
Martin v. Löwis44f86962001-09-05 13:44:54 +00001207- Asynchronous timeout actions are available through the new class
1208 threading.Timer.
1209
Tim Peters78526162001-09-05 00:53:45 +00001210- math.log and math.log10 now return sensible results for even huge
1211 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1212
Tim Petersbdee63f2001-09-02 03:40:59 +00001213- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001214 currently held. See the docs for the imp module.
1215
Tim Petersbdee63f2001-09-02 03:40:59 +00001216- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001217 dumps containing ints written on platforms where Python ints are 8 bytes.
1218 When read on a box where Python ints are 4 bytes, such values are
1219 converted to Python longs.
1220
Tim Petersbdee63f2001-09-02 03:40:59 +00001221- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001222 code objects is no longer allowed. This plugs a security hole.
1223
Steve Purcell6091cd62001-09-06 16:05:17 +00001224- unittest.TestResult instances no longer store references to tracebacks
1225 generated by test failures. This prevents unexpected dangling references
1226 to objects that should be garbage collected between tests.
1227
Tim Petersedc99312001-08-22 21:36:50 +00001228Tools
1229
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001230- Tools/scripts/fixdiv.py has been added which can be used to fix
1231 division operators as per PEP 238.
1232
Tim Petersedc99312001-08-22 21:36:50 +00001233Build
1234
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001235- If you are an adventurous person using Mac OS X you may want to look at
1236 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1237 application, which can be used for experimenting with Carbon or Cocoa.
1238 Discussion of this on pythonmac-sig, please.
1239
Tim Peters7eea37e2001-09-04 22:08:56 +00001240C API
1241
1242- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001243
Tim Peters9fffa3e2001-09-04 05:14:19 +00001244- Note that PyLong_AsDouble can fail! This has always been true, but no
1245 callers checked for it. It's more likely to fail now, because overflow
1246 errors are properly detected now. The proper way to check:
1247
1248 double x = PyLong_AsDouble(some_long_object);
1249 if (x == -1.0 && PyErr_Occurred()) {
1250 /* The conversion failed. */
1251 }
1252
Tim Petersbdee63f2001-09-02 03:40:59 +00001253- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001254 compile but will not participate in GC. To upgrade an extension
1255 module:
1256
1257 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001258
Neil Schemenauer4042c692001-08-30 15:38:01 +00001259 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1260 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001261
Neil Schemenauer4042c692001-08-30 15:38:01 +00001262 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1263 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001264
Neil Schemenauer4042c692001-08-30 15:38:01 +00001265 - remove PyGC_HEAD_SIZE from object size calculations
1266
1267 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1268
Tim Petersbdee63f2001-09-02 03:40:59 +00001269- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001270 These can be used safely to construct string objects from a
1271 sprintf-style format string (similar to the format string supported
1272 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001273
Tim Petersedc99312001-08-22 21:36:50 +00001274New platforms
1275
Tim Petersb7da0902001-09-02 23:01:43 +00001276- Stephen Hansen contributed patches sufficient to get a clean compile
1277 under Borland C (Windows), but he reports problems running it and ran
1278 out of time to complete the port. Volunteers? Expect a MemoryError
1279 when importing the types module; this is probably shallow, and
1280 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001281
Tim Petersedc99312001-08-22 21:36:50 +00001282Tests
1283
1284Windows
1285
Tim Peters6e13a562001-09-06 00:32:15 +00001286- Large file support is now enabled on Win32 platforms as well as on
1287 Win64. This means that, for example, you can use f.tell() and f.seek()
1288 to manipulate files larger than 2 gigabytes (provided you have enough
1289 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001290 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1291 filesize limit, and large file support makes no difference there.
1292 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1293 NTFS has no practical limit on file size, and files of any size can be
1294 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001295
Tim Petersbdee63f2001-09-02 03:40:59 +00001296- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001297 points to command.com (patch from Brian Quinlan).
1298
Tim Petersedc99312001-08-22 21:36:50 +00001299
Tim Peters20f51a72001-07-21 02:31:40 +00001300What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001301Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001302===========================
1303
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001304Build
1305
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001306- Tim Peters developed a brand new Windows installer using Wise 8.1,
1307 generously donated to us by Wise Solutions.
1308
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001309- configure supports a new option --enable-unicode, with the values
1310 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1311 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001312
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001313- A new configure option --enable-framework builds a Mac OS X framework,
1314 which "make frameworkinstall" will install. This provides a starting
1315 point for more mac-like functionality, join pythonmac-sig@python.org
1316 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001317
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001318- The NeXT platform is no longer supported.
1319
1320- The `new' module is now statically linked.
1321
Tim Peters0afb6092001-08-15 06:06:44 +00001322Tools
1323
1324- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001325 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001326 the module docstring for details.
1327
Tim Peters20f51a72001-07-21 02:31:40 +00001328Tests
1329
Tim Peters5e824c32001-08-12 22:25:01 +00001330- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001331 platforms, allowing to give clearer test result output. regrtest
1332 also has optional --use/-u switch to run normally disabled tests
1333 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001334
Tim Peters20f51a72001-07-21 02:31:40 +00001335- Several new tests in the standard test suite, with special thanks to
1336 Nick Mathewson.
1337
1338Core
1339
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001340- The floor division operator // has been added as outlined in PEP
1341 238. The / operator still provides classic division (and will until
1342 Python 3.0) unless "from __future__ import division" is included, in
1343 which case the / operator will provide true division. The operator
1344 module provides truediv() and floordiv() functions. Augmented
1345 assignment variants are included, as are the equivalent overloadable
1346 methods and C API methods. See the PEP for a full discussion:
1347 <http://python.sf.net/peps/pep-0238.html>
1348
Tim Peters6cd6a822001-08-17 22:11:27 +00001349- Future statements are now effective in simulated interactive shells
1350 (like IDLE). This should "just work" by magic, but read Michael
1351 Hudson's "Future statements in simulated shells" PEP 264 for full
1352 details: <http://python.sf.net/peps/pep-0264.html>.
1353
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001354- The type/class unification (PEP 252-253) was integrated into the
1355 trunk and is not so tentative any more (the exact specification of
1356 some features is still tentative). A lot of work has done on fixing
1357 bugs and adding robustness and features (performance still has to
1358 come a long way).
1359
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001360- Warnings about a mismatch in the Python API during extension import
1361 now use the Python warning framework (which makes it possible to
1362 write filters for these warnings).
1363
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001364- A function's __dict__ (aka func_dict) will now always be a
1365 dictionary. It used to be possible to delete it or set it to None,
1366 but now both actions raise TypeErrors. It is still legal to set it
1367 to a dictionary object. Getting func.__dict__ before any attributes
1368 have been assigned now returns an empty dictionary instead of None.
1369
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001370- A new command line option, -E, was added which disables the use of
1371 all environment variables, or at least those that are specifically
1372 significant to Python. Usually those have a name starting with
1373 "PYTHON". This was used to fix a problem where the tests fail if
1374 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1375 older distribution.
1376
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001377Library
1378
Tim Peters5e824c32001-08-12 22:25:01 +00001379- New class Differ and new functions ndiff() and restore() in difflib.py.
1380 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001381 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001382
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001383- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1384 value using the minimal quoting required for the value; more
1385 reliable than using xml.sax.saxutils.escape() for attribute values.
1386
1387- Readline completion support for cmd.Cmd was added.
1388
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001389- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1390
1391- Added function threading.BoundedSemaphore()
1392
1393- Added Ka-Ping Yee's cgitb.py module.
1394
1395- The `new' module now exposes the CO_xxx flags.
1396
Martin v. Löwis560da622001-11-24 09:24:51 +00001397- The gc module offers the get_referents function.
1398
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001399New platforms
1400
1401C API
1402
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001403- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1404 which provide a cross-platform implementations for the
1405 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1406 the standard sprintf() and vsprintf() C lib APIs, these versions
1407 apply bounds checking on the used buffer which enhances protection
1408 against buffer overruns.
1409
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001410- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001411 and extensions using different Unicode widths is rendered next to
1412 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001413 will result in an ImportError. Unicode extensions writers must make
1414 sure to check the Unicode width compatibility in their extensions by
1415 using at least one of the mangled Unicode APIs in the extension.
1416
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001417- Two new flags METH_NOARGS and METH_O are available in method definition
1418 tables to simplify implementation of methods with no arguments and a
1419 single untyped argument. Calling such methods is more efficient than
1420 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1421 deprecated.
1422
Tim Petersc1731372001-08-04 08:12:36 +00001423Windows
1424
1425- "import module" now compiles module.pyw if it exists and nothing else
1426 relevant is found.
1427
Tim Peters20f51a72001-07-21 02:31:40 +00001428
Guido van Rossum55a78992001-07-17 17:22:32 +00001429What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001430Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001431===========================
1432
1433Core
Tim Petersa814db52001-05-14 07:05:58 +00001434
Tim Peters6d6c1a32001-08-02 04:15:00 +00001435- TENTATIVELY, a large amount of code implementing much of what's
1436 described in PEP 252 (Making Types Look More Like Classes) and PEP
1437 253 (Subtyping Built-in Types) was added. This will be released
1438 with Python 2.2a1. Documentation will be provided separately
1439 through http://www.python.org/2.2/. The purpose of releasing this
1440 with Python 2.2a1 is to test backwards compatibility. It is
1441 possible, though not likely, that a decision is made not to release
1442 this code as part of 2.2 final, if any serious backwards
1443 incompapatibilities are found during alpha testing that cannot be
1444 repaired.
1445
Guido van Rossum55a78992001-07-17 17:22:32 +00001446- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001447 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001448 more 'yield' statements. See PEP 255. Since this adds a new
1449 keyword to the language, this feature must be enabled by including a
1450 future statement: "from __future__ import generators" (see PEP 236).
1451 Generators will become a standard feature in a future release
1452 (probably 2.3). Without this future statement, 'yield' remains an
1453 ordinary identifier, but a warning is issued each time it is used.
1454 (These warnings currently don't conform to the warnings framework of
1455 PEP 230; we intend to fix this in 2.2a2.)
1456
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001457- The UTF-16 codec was modified to be more RFC compliant. It will now
1458 only remove BOM characters at the start of the string and then
1459 only if running in native mode (UTF-16-LE and -BE won't remove a
1460 leading BMO character).
1461
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001462- Strings now have a new method .decode() to complement the already
1463 existing .encode() method. These two methods provide direct access
1464 to the corresponding decoders and encoders of the registered codecs.
1465
1466 To enhance the usability of the .encode() method, the special
1467 casing of Unicode object return values was dropped (Unicode objects
1468 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001469
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001470 Both methods will now return whatever the codec in charge of the
1471 requested encoding returns as object, e.g. Unicode codecs will
1472 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1473 will return u"äöü"). This enables codec writer to create codecs
1474 for various simple to use conversions.
1475
1476 New codecs were added to demonstrate these new features (the .encode()
1477 and .decode() columns indicate the type of the returned objects):
1478
1479 Name | .encode() | .decode() | Description
1480 ----------------------------------------------------------------------
1481 uu | string | string | UU codec (e.g. for email)
1482 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001483 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001484 zlib | string | string | zlib compression
1485 hex | string | string | 2-byte hex codec
1486 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1487
Mark Hammond2a0af792001-05-14 03:09:36 +00001488- Some operating systems now support the concept of a default Unicode
1489 encoding for file system operations. Notably, Windows supports 'mbcs'
1490 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001491 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001492 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001493
1494 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001495 functions that return filenames (such as os.listdir()) to return Python
1496 string objects pre-encoded using the default file system encoding for
1497 the platform. As this encoding is likely to be different from Python's
1498 default encoding, converting this name to a Unicode object before passing
1499 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001500 would attempt to use its default encoding (generally ASCII) rather than
1501 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001502
Tim Petersa814db52001-05-14 07:05:58 +00001503 In general, this change simply removes surprises when working with
1504 Unicode and the file system, making these operations work as you expect,
1505 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001506 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001507
Tim Peters61dff2b2001-05-08 15:43:37 +00001508- Float (and complex) literals in source code were evaluated to full
1509 precision only when running from a .py file; the same code loaded from a
1510 .pyc (or .pyo) file could suffer numeric differences starting at about the
1511 12th significant decimal digit. For example, on a machine with IEEE-754
1512 floating arithmetic,
1513
1514 x = 9007199254740992.0
1515 print long(x)
1516
1517 printed 9007199254740992 if run directly from .py, but 9007199254740000
1518 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1519 str(float) instead of repr(float) when building code objects. marshal
1520 now uses repr(float) instead, which should reproduce floats to full
1521 machine precision (assuming the platform C float<->string I/O conversion
1522 functions are of good quality).
1523
1524 This may cause floating-point results to change in some cases, and
1525 usually for the better, but may also cause numerically unstable
1526 algorithms to break.
1527
Tim Peters2f228e72001-05-13 00:19:31 +00001528- The implementation of dicts suffers fewer collisions, which has speed
1529 benefits. However, the order in which dict entries appear in dict.keys(),
1530 dict.values() and dict.items() may differ from previous releases for a
1531 given dict. Nothing is defined about this order, so no program should
1532 rely on it. Nevertheless, it's easy to write test cases that rely on the
1533 order by accident, typically because of printing the str() or repr() of a
1534 dict to an "expected results" file. See Lib/test/test_support.py's new
1535 sortdict(dict) function for a simple way to display a dict in sorted
1536 order.
1537
Tim Peters7a3bfc32001-06-12 01:22:22 +00001538- Many other small changes to dicts were made, resulting in faster
1539 operation along the most common code paths.
1540
Guido van Rossum10315822001-05-01 20:54:30 +00001541- Dictionary objects now support the "in" operator: "x in dict" means
1542 the same as dict.has_key(x).
1543
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001544- The update() method of dictionaries now accepts generic mapping
1545 objects. Specifically the argument object must support the .keys()
1546 and __getitem__() methods. This allows you to say, for example,
1547 {}.update(UserDict())
1548
Guido van Rossum10315822001-05-01 20:54:30 +00001549- Iterators were added; this is a generalized way of providing values
1550 to a for loop. See PEP 234. There's a new built-in function iter()
1551 to return an iterator. There's a new protocol to get the next value
1552 from an iterator using the next() method (in Python) or the
1553 tp_iternext slot (in C). There's a new protocol to get iterators
1554 using the __iter__() method (in Python) or the tp_iter slot (in C).
1555 Iterating (i.e. a for loop) over a dictionary generates its keys.
1556 Iterating over a file generates its lines.
1557
Tim Petersf553f892001-05-01 20:45:31 +00001558- The following functions were generalized to work nicely with iterator
1559 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001560 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001561 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1562 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001563 join() method of strings
1564 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001565 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1566 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001567 right-hand side of assignment statements with multiple targets, such as
1568 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001569
Tim Petersd85e1022001-05-11 21:51:48 +00001570- Accessing module attributes is significantly faster (for example,
1571 random.random or os.path or yourPythonModule.yourAttribute).
1572
Tim Peterse63415e2001-05-08 04:38:29 +00001573- Comparing dictionary objects via == and != is faster, and now works even
1574 if the keys and values don't support comparisons other than ==.
1575
Tim Peters95bf9392001-05-10 08:32:44 +00001576- Comparing dictionaries in ways other than == and != is slower: there were
1577 insecurities in the dict comparison implementation that could cause Python
1578 to crash if the element comparison routines for the dict keys and/or
1579 values mutated the dicts. Making the code bulletproof slowed it down.
1580
Tim Peterseb28ef22001-06-02 05:27:19 +00001581- Collisions in dicts are resolved via a new approach, which can help
1582 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001583 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001584 faster now. Thanks to Christian Tismer for pointing out the cause and
1585 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001586
Tim Peters52e155e2001-06-16 05:42:57 +00001587- repr() is much faster for large containers (dict, list, tuple).
1588
1589
Tim Petersa814db52001-05-14 07:05:58 +00001590Library
1591
Fred Drake960fdf92001-07-20 18:38:26 +00001592- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1593 were added to the string module. These a locale-indenpendent
1594 constants, unlike letters, lowercase, and uppercase. These are now
1595 use in appropriate locations in the standard library.
1596
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001597- The flags used in dlopen calls can now be configured using
1598 sys.setdlopenflags and queried using sys.getdlopenflags.
1599
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001600- Fredrik Lundh's xmlrpclib is now a standard library module. This
1601 provides full client-side XML-RPC support. In addition,
1602 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1603 one asyncore-based). Thanks to Eric Raymond for the documentation.
1604
Guido van Rossum643d3912001-07-05 14:46:25 +00001605- The xrange() object is simplified: it no longer supports slicing,
1606 repetition, comparisons, efficient 'in' checking, the tolist()
1607 method, or the start, stop and step attributes. See PEP 260.
1608
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001609- A new function fnmatch.filter to filter lists of file names was added.
1610
Barry Warsawffd674d2001-05-22 16:00:10 +00001611- calendar.py uses month and day names based on the current locale.
1612
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001613- strop is now *really* obsolete (this was announced before with 1.6),
1614 and issues DeprecationWarning when used (except for the four items
1615 that are still imported into string.py).
1616
Tim Petersa814db52001-05-14 07:05:58 +00001617- Cookie.py now sorts key+value pairs by key in output strings.
1618
1619- pprint.isrecursive(object) didn't correctly identify recursive objects.
1620 Now it does.
1621
Tim Peters95b3f782001-05-14 18:39:41 +00001622- pprint functions now much faster for large containers (tuple, list, dict).
1623
Tim Peters7b9542a2001-06-10 23:40:19 +00001624- New 'q' and 'Q' format codes in the struct module, corresponding to C
1625 types "long long" and "unsigned long long" (on Windows, __int64). In
1626 native mode, these can be used only when the platform C compiler supports
1627 these types (when HAVE_LONG_LONG is #define'd by the Python config
1628 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001629 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1630 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001631
Guido van Rossum83213cc2001-06-12 16:48:52 +00001632- The site module installs a new built-in function 'help' that invokes
1633 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1634 it displays a message reminding the user to use 'help()' or
1635 'help(object)'.
1636
Tim Petersa814db52001-05-14 07:05:58 +00001637Tests
1638
1639- New test_mutants.py runs dict comparisons where the key and value
1640 comparison operators mutute the dicts randomly during comparison. This
1641 rapidly causes Python to crash under earlier releases (not for the faint
1642 of heart: it can also cause Win9x to freeze or reboot!).
1643
1644- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001645 pprint.isreadable() return sensible results. Also verifies that simple
1646 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001647
Tim Peters4324aa32001-05-28 22:30:08 +00001648C API
1649
1650- Removed the unused last_is_sticky argument from the internal
1651 _PyTuple_Resize(). If this affects you, you were cheating.
1652
1653
Guido van Rossum55a78992001-07-17 17:22:32 +00001654======================================================================
1655
1656
Guido van Rossumffe13be2001-04-16 18:46:45 +00001657What's New in Python 2.1 (final)?
1658=================================
1659
1660We only changed a few things since the last release candidate, all in
1661Python library code:
1662
1663- A bug in the locale module was fixed that affected locales which
1664 define no grouping for numeric formatting.
1665
1666- A few bugs in the weakref module's implementations of weak
1667 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1668 and the test suite was updated to check for these bugs.
1669
1670- An old bug in the os.path.walk() function (introduced in Python
1671 2.0!) was fixed: a non-existent file would cause an exception
1672 instead of being ignored.
1673
1674- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1675 PyChecker.
1676
1677
Guido van Rossum5b08f132001-04-16 02:05:23 +00001678What's New in Python 2.1c2?
1679===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001680
Guido van Rossum5b08f132001-04-16 02:05:23 +00001681A flurry of small changes, and one showstopper fixed in the nick of
1682time made it necessary to release another release candidate. The list
1683here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001684
Guido van Rossum5b08f132001-04-16 02:05:23 +00001685Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001686
Guido van Rossum5b08f132001-04-16 02:05:23 +00001687- Tim discovered a nasty bug in the dictionary code, caused by
1688 PyDict_Next() calling dict_resize(), and the GC code's use of
1689 PyDict_Next() violating an assumption in dict_items(). This was
1690 fixed with considerable amounts of band-aid, but the net effect is a
1691 saner and more robust implementation.
1692
1693- Made a bunch of symbols static that were accidentally global.
1694
1695Build and Ports
1696
1697- The setup.py script didn't check for a new enough version of zlib
1698 (1.1.3 is needed). Now it does.
1699
1700- Changed "make clean" target to also remove shared libraries.
1701
1702- Added a more general warning about the SGI Irix optimizer to README.
1703
1704Library
1705
1706- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1707 omitted the slash between host and file.html.
1708
1709- The mailbox module's _Mailbox class contained a completely broken
1710 and undocumented seek() method. Ripped it out.
1711
1712- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1713 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1714
1715- Fixed a few last-minute bugs in unittest.
1716
1717Extensions
1718
1719- Reverted the patch to the OpenSSL code in socketmodule.c to support
1720 RAND_status() and the EGD, and the subsequent patch that tried to
1721 fix it for pre-0.9.5 versions; the problem with the patch is that on
1722 some systems it issues a warning whenever socket is imported, and
1723 that's unacceptable.
1724
1725Tests
1726
1727- Fixed the pickle tests to work with "import test.test_pickle".
1728
1729- Tweaked test_locale.py to actually run the test Windows.
1730
1731- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1732 not "wb" (which is not a valid mode at all).
1733
1734- Fix pstats browser crashes. Import readline if it exists to make
1735 the user interface nicer.
1736
1737- Add "import thread" to the top of test modules that import the
1738 threading module (test_asynchat and test_threadedtempfile). This
1739 prevents test failures caused by a broken threading module resulting
1740 from a previously caught failed import.
1741
1742- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1743 needed on some platforms (e.g. Solaris 8) when the tests are run
1744 twice in succession.
1745
1746- Skip rather than fail test_sunaudiodev if no audio device is found.
1747
1748
1749What's New in Python 2.1c1?
1750===========================
1751
1752This list was significantly updated when 2.1c2 was released; the 2.1c1
1753release didn't mention most changes that were actually part of 2.1c1:
1754
1755Legal
1756
1757- Copyright was assigned to the Python Software Foundation (PSF) and a
1758 PSF license (very similar to the CNRI license) was added.
1759
1760- The CNRI copyright notice was updated to include 2001.
1761
1762Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001763
Guido van Rossumc9932722001-04-12 02:31:27 +00001764- After a public outcry, assignment to __debug__ is no longer illegal;
1765 instead, a warning is issued. It will become illegal in 2.2.
1766
Guido van Rossum5b08f132001-04-16 02:05:23 +00001767- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1768 "%#x" now always prepends "0x", even if the value is zero.
1769
1770- Fixed some nits in the bytecode compiler.
1771
1772- Fixed core dumps when calling certain kinds of non-functions.
1773
1774- Fixed various core dumps caused by reference count bugs.
1775
1776Build and Ports
1777
1778- Use INSTALL_SCRIPT to install script files.
1779
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001780- New port: SCO Unixware 7, by Billy G. Allie.
1781
Guido van Rossum5b08f132001-04-16 02:05:23 +00001782- Updated RISCOS port.
1783
1784- Updated BeOS port and notes.
1785
1786- Various other porting problems resolved.
1787
1788Library
1789
1790- The TERMIOS and SOCKET modules are now truly obsolete and
1791 unnecessary. Their symbols are incorporated in the termios and
1792 socket modules.
1793
1794- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1795 better tests for pickling.
1796
1797- threading: make Condition.wait() robust against KeyboardInterrupt.
1798
1799- zipfile: add support to zipfile to support opening an archive
1800 represented by an open file rather than a file name. Fix bug where
1801 the archive was not properly closed. Fixed a bug in this bugfix
1802 where flush() was called for a read-only file.
1803
1804- imputil: added an uninstall() method to the ImportManager.
1805
1806- Canvas: fixed bugs in lower() and tkraise() methods.
1807
1808- SocketServer: API change (added overridable close_request() method)
1809 so that the TCP server can explicitly close the request.
1810
1811- pstats: Eric Raymond added a simple interactive statistics browser,
1812 invoked when the module is run as a script.
1813
1814- locale: fixed a problem in format().
1815
1816- webbrowser: made it work when the BROWSER environment variable has a
1817 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1818 KDE 2. Fixed some other nits.
1819
1820- unittest: changes to allow using a different exception than
1821 AssertionError, and added a few more function aliases. Some other
1822 small changes.
1823
1824- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1825
1826- asynchat: fixed a critical bug in asynchat that slipped through the
1827 2.1b2 release. Fixed another rare bug.
1828
1829- Fix some unqualified except: clauses (always a bad code example).
1830
1831XML
1832
1833- pyexpat: new API get_version_string().
1834
1835- Fixed some minidom bugs.
1836
1837Extensions
1838
1839- Fixed a core dump in _weakref. Removed the weakref.mapping()
1840 function (it adds nothing to the API).
1841
1842- Rationalized the use of header files in the readline module, to make
1843 it compile (albeit with some warnings) with the very recent readline
1844 4.2, without breaking for earlier versions.
1845
1846- Hopefully fixed a buffering problem in linuxaudiodev.
1847
1848- Attempted a fix to make the OpenSSL support in the socket module
1849 work again with pre-0.9.5 versions of OpenSSL.
1850
1851Tests
1852
1853- Added a test case for asynchat and asyncore.
1854
1855- Removed coupling between tests where one test failing could break
1856 another.
1857
1858Tools
1859
1860- Ping added an interactive help browser to pydoc, fixed some nits
1861 in the rest of the pydoc code, and added some features to his
1862 inspect module.
1863
1864- An updated python-mode.el version 4.1 which integrates Ken
1865 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1866 much nicer in XEmacs and Emacs. When stepping through your program
1867 with pdb, in either the shell window or the *Python* window, the
1868 source file and line will be tracked by an arrow. Very cool!
1869
1870- IDLE: syntax warnings in interactive mode are changed into errors.
1871
1872- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001873 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001874
1875- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001876
Barry Warsaw11e89c72001-04-11 20:37:57 +00001877
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001878What's New in Python 2.1 beta 2?
1879================================
1880
Guido van Rossum053ae352001-03-22 14:17:21 +00001881(Unlisted are many fixed bugs, more documentation, etc.)
1882
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001883Core language, builtins, and interpreter
1884
Guido van Rossum053ae352001-03-22 14:17:21 +00001885- The nested scopes work (enabled by "from __future__ import
1886 nested_scopes") is completed; in particular, the future now extends
1887 into code executed through exec, eval() and execfile(), and into the
1888 interactive interpreter.
1889
1890- When calling a base class method (e.g. BaseClass.__init__(self)),
1891 this is now allowed even if self is not strictly spoken a class
1892 instance (e.g. when using metaclasses or the Don Beaudry hook).
1893
1894- Slice objects are now comparable but not hashable; this prevents
1895 dict[:] from being accepted but meaningless.
1896
1897- Complex division is now calculated using less braindead algorithms.
1898 This doesn't change semantics except it's more likely to give useful
1899 results in extreme cases. Complex repr() now uses full precision
1900 like float repr().
1901
1902- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1903
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001904- It is illegal to assign to the name __debug__, which is set when the
1905 interpreter starts. It is effectively a compile-time constant.
1906
1907- A warning will be issued if a global statement for a variable
1908 follows a use or assignment of that variable.
1909
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001910Standard library
1911
Guido van Rossum053ae352001-03-22 14:17:21 +00001912- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1913 inspired by JUnit), is now part of the standard library. You now
1914 have a choice of two testing frameworks: unittest requires you to
1915 write testcases as separate code, doctest gathers them from
1916 docstrings. Both approaches have their advantages and
1917 disadvantages.
1918
1919- A new module Tix was added, which wraps the Tix extension library
1920 for Tk. With that module, it is not necessary to statically link
1921 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1922 require" command. See Demo/tix/.
1923
1924- tzparse.py is now obsolete.
1925
1926- In gzip.py, the seek() and tell() methods are removed -- they were
1927 non-functional anyway, and it's better if callers can test for their
1928 existence with hasattr().
1929
1930Python/C API
1931
1932- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1933 that's already in the dictionary during a PyDict_Next() iteration.
1934 This used to fail occasionally when a dictionary resize operation
1935 could be triggered that would rehash all the keys. All other
1936 modifications to the dictionary are still off-limits during a
1937 PyDict_Next() iteration!
1938
1939- New extended APIs related to passing compiler variables around.
1940
1941- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1942 implement isinstance() and issubclass().
1943
1944- Py_BuildValue() now has a "D" conversion to create a Python complex
1945 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001946
Fred Drake4e262a92001-03-22 18:26:47 +00001947- Extensions types which support weak references must now set the
1948 field allocated for the weak reference machinery to NULL themselves;
1949 this is done to avoid the cost of checking each object for having a
1950 weakly referencable type in PyObject_INIT(), since most types are
1951 not weakly referencable.
1952
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001953- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1954 free variables and cell variables to and from the frame's f_locals.
1955
1956- Variants of several functions defined in pythonrun.h have been added
1957 to support the nested_scopes future statement. The variants all end
1958 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1959 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1960 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001961 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001962
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001963Distutils
1964
1965- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1966 into the release tree.
1967
Tim Peters0e57abf2001-05-02 07:39:38 +00001968- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001969 (an uninstaller, more customization of the installer's display)
1970
1971- from Jack Jansen: added Mac-specific code to generate a dialog for
1972 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001973 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001974 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001975
1976- added 'platforms' and 'keywords' to the set of metadata that can be
1977 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001978
1979- applied patches from Jason Tishler to make the compiler class work with
1980 Cygwin.
1981
1982
Tim Peters2fe289a2001-03-01 22:19:38 +00001983What's New in Python 2.1 beta 1?
1984================================
Tim Petersd66595f2001-02-04 03:09:53 +00001985
1986Core language, builtins, and interpreter
1987
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001988- Following an outcry from the community about the amount of code
1989 broken by the nested scopes feature introduced in 2.1a2, we decided
1990 to make this feature optional, and to wait until Python 2.2 (or at
1991 least 6 months) to make it standard. The option can be enabled on a
1992 per-module basis by adding "from __future__ import nested_scopes" at
1993 the beginning of a module (before any other statements, but after
1994 comments and an optional docstring). See PEP 236 (Back to the
1995 __future__) for a description of the __future__ statement. PEP 227
1996 (Statically Nested Scopes) has been updated to reflect this change,
1997 and to clarify the semantics in a number of endcases.
1998
1999- The nested scopes code, when enabled, has been hardened, and most
2000 bugs and memory leaks in it have been fixed.
2001
2002- Compile-time warnings are now generated for a number of conditions
2003 that will break or change in meaning when nested scopes are enabled:
2004
2005 - Using "from...import *" or "exec" without in-clause in a function
2006 scope that also defines a lambda or nested function with one or
2007 more free (non-local) variables. The presence of the import* or
2008 bare exec makes it impossible for the compiler to determine the
2009 exact set of local variables in the outer scope, which makes it
2010 impossible to determine the bindings for free variables in the
2011 inner scope. To avoid the warning about import *, change it into
2012 an import of explicitly name object, or move the import* statement
2013 to the global scope; to avoid the warning about bare exec, use
2014 exec...in... (a good idea anyway -- there's a possibility that
2015 bare exec will be deprecated in the future).
2016
2017 - Use of a global variable in a nested scope with the same name as a
2018 local variable in a surrounding scope. This will change in
2019 meaning with nested scopes: the name in the inner scope will
2020 reference the variable in the outer scope rather than the global
2021 of the same name. To avoid the warning, either rename the outer
2022 variable, or use a global statement in the inner function.
2023
Neil Schemenauera35c6882001-02-27 04:45:05 +00002024- An optional object allocator has been included. This allocator is
2025 optimized for Python objects and should be faster and use less memory
2026 than the standard system allocator. It is not enabled by default
2027 because of possible thread safety problems. The allocator is only
2028 protected by the Python interpreter lock and it is possible that some
2029 extension modules require a thread safe allocator. The object
2030 allocator can be enabled by providing the "--with-pymalloc" option to
2031 configure.
2032
Tim Petersd66595f2001-02-04 03:09:53 +00002033Standard library
2034
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002035- pyexpat now detects the expat version if expat.h defines it. A
2036 number of additional handlers are provided, which are only available
2037 since expat 1.95. In addition, the methods SetParamEntityParsing and
2038 GetInputContext of Parser objects are available with 1.95.x
2039 only. Parser objects now provide the ordered_attributes and
2040 specified_attributes attributes. A new module expat.model was added,
2041 which offers a number of additional constants if 1.95.x is used.
2042
2043- xml.dom offers the new functions registerDOMImplementation and
2044 getDOMImplementation.
2045
2046- xml.dom.minidom offers a toprettyxml method. A number of DOM
2047 conformance issues have been resolved. In particular, Element now
2048 has an hasAttributes method, and the handling of namespaces was
2049 improved.
2050
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002051- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2052 getting information about live Python code, and pydoc.py, a module
2053 for interactively converting docstrings to HTML or text.
2054 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002055 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002056 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2057 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002058
Tim Peters1eff7962001-03-01 02:31:33 +00002059- New library module difflib.py, primarily packaging the SequenceMatcher
2060 class at the heart of the popular ndiff.py file-comparison tool.
2061
2062- doctest.py (a framework for verifying Python code examples in docstrings)
2063 is now part of the std library.
2064
Tim Petersd66595f2001-02-04 03:09:53 +00002065Windows changes
2066
Guido van Rossume3955a82001-03-02 14:05:59 +00002067- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2068 small GUI that lets you browse the module docstrings using your
2069 default web browser.
2070
Tim Peters1eff7962001-03-01 02:31:33 +00002071- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2072 Platforms) is implemented. See
2073
2074 http://python.sourceforge.net/peps/pep-0235.html
2075
2076 for full details, especially the "Current Lower-Left Semantics" section.
2077 The new Windows import rules are simpler than before:
2078
2079 A. If the PYTHONCASEOK environment variable exists, same as
2080 before: silently accept the first case-insensitive match of any
2081 kind; raise ImportError if none found.
2082
2083 B. Else search sys.path for the first case-sensitive match; raise
2084 ImportError if none found.
2085
2086 The same rules have been implented on other platforms with case-
2087 insensitive but case-preserving filesystems too (including Cygwin, and
2088 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002089
Tim Peters25a9ce32001-02-19 07:06:36 +00002090- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2091 what it's supposed to do (and does do under NT and 2000) via direct
2092 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002093 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002094 all Win9x systems before.
2095
Tim Peters1eff7962001-03-01 02:31:33 +00002096- Build: Subproject _test (effectively) renamed to _testcapi.
2097
Tim Peters2fe289a2001-03-01 22:19:38 +00002098New platforms
2099
2100- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2101 Thanks to Steven Majewski!
2102
2103- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2104 Tishler!
2105
Guido van Rossum9089b272001-03-02 06:49:50 +00002106- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2107 Schwertberger! See RISCOS/README for more information -- it seems
2108 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002109 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002110
Tim Peters25a9ce32001-02-19 07:06:36 +00002111
Tim Petersd7b5e882001-01-25 03:36:26 +00002112What's New in Python 2.1 alpha 2?
2113=================================
Tim Peters40ead762001-01-27 05:35:26 +00002114
Tim Petersd7b5e882001-01-25 03:36:26 +00002115Core language, builtins, and interpreter
2116
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002117- Scopes nest. If a name is used in a function or class, but is not
2118 local, the definition in the nearest enclosing function scope will
2119 be used. One consequence of this change is that lambda statements
2120 could reference variables in the namespaces where the lambda is
2121 defined. In some unusual cases, this change will break code.
2122
2123 In all previous version of Python, names were resolved in exactly
2124 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002125 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002126 function A is defined within a function B, the names bound in B are
2127 not visible in A. The new rules make names bound in B visible in A,
2128 unless A contains a name binding that hides the binding in B.
2129
2130 Section 4.1 of the reference manual describes the new scoping rules
2131 in detail. The test script in Lib/test/test_scope.py demonstrates
2132 some of the effects of the change.
2133
2134 The new rules will cause existing code to break if it defines nested
2135 functions where an outer function has local variables with the same
2136 name as globals or builtins used by the inner function. Example:
2137
2138 def munge(str):
2139 def helper(x):
2140 return str(x)
2141 if type(str) != type(''):
2142 str = helper(str)
2143 return str.strip()
2144
2145 Under the old rules, the name str in helper() is bound to the
2146 builtin function str(). Under the new rules, it will be bound to
2147 the argument named str and an error will occur when helper() is
2148 called.
2149
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002150- The compiler will report a SyntaxError if "from ... import *" occurs
2151 in a function or class scope. The language reference has documented
2152 that this case is illegal, but the compiler never checked for it.
2153 The recent introduction of nested scope makes the meaning of this
2154 form of name binding ambiguous. In a future release, the compiler
2155 may allow this form when there is no possibility of ambiguity.
2156
Tim Peters40ead762001-01-27 05:35:26 +00002157- repr(string) is easier to read, now using hex escapes instead of octal,
2158 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2159
2160 >>> "\texample \r\n" + chr(0) + chr(255)
2161 '\texample \r\n\x00\xff' # in 2.1
2162 '\011example \015\012\000\377' # in 2.0
2163
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002164- Functions are now compared and hashed by identity, not by value, since
2165 the func_code attribute is writable.
2166
Fred Drakefb9d7122001-02-01 20:00:40 +00002167- Weak references (PEP 205) have been added. This involves a few
2168 changes in the core, an extension module (_weakref), and a Python
2169 module (weakref). The weakref module is the public interface. It
2170 includes support for "explicit" weak references, proxy objects, and
2171 mappings with weakly held values.
2172
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002173- A 'continue' statement can now appear in a try block within the body
2174 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002175 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002176
Tim Petersd7b5e882001-01-25 03:36:26 +00002177Standard library
2178
Barry Warsaw30dbd142001-01-31 22:14:01 +00002179- mailbox.py now has a new class, PortableUnixMailbox which is
2180 identical to UnixMailbox but uses a more portable scheme for
2181 determining From_ separators. Also, the constructors for all the
2182 classes in this module have a new optional `factory' argument, which
2183 is a callable used when new message classes must be instantiated by
2184 the next() method.
2185
Tim Petersd7b5e882001-01-25 03:36:26 +00002186- random.py is now self-contained, and offers all the functionality of
2187 the now-deprecated whrandom.py. See the docs for details. random.py
2188 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002189 and restoring the internal state of the generator; and jumpahead(n),
2190 for quickly forcing the internal state to be the same as if n calls to
2191 random() had been made. The latter is particularly useful for multi-
2192 threaded programs, creating one instance of the random.Random() class for
2193 each thread, then using .jumpahead() to force each instance to use a
2194 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002195
Tim Peters0de88fc2001-02-01 04:59:18 +00002196- random.py's seed() function is new. For bit-for-bit compatibility with
2197 prior releases, use the whseed function instead. The new seed function
2198 addresses two problems: (1) The old function couldn't produce more than
2199 about 2**24 distinct internal states; the new one about 2**45 (the best
2200 that can be done in the Wichmann-Hill generator). (2) The old function
2201 sometimes produced identical internal states when passed distinct
2202 integers, and there was no simple way to predict when that would happen;
2203 the new one guarantees to produce distinct internal states for all
2204 arguments in [0, 27814431486576L).
2205
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002206- The socket module now supports raw packets on Linux. The socket
2207 family is AF_PACKET.
2208
Tim Peters9ea17ac2001-02-02 05:57:15 +00002209- test_capi.py is a start at running tests of the Python C API. The tests
2210 are implemented by the new Modules/_testmodule.c.
2211
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002212- A new extension module, _symtable, provides provisional access to the
2213 internal symbol table used by the Python compiler. A higher-level
2214 interface will be added on top of _symtable in a future release.
2215
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002216- Removed the obsolete soundex module.
2217
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002218- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2219 the isSameNode method; NamedNodeMap the get method.
2220
2221- xml.sax.expatreader supports the lexical handler property; it
2222 generates comment, startCDATA, and endCDATA events.
2223
Tim Petersee826f82001-01-31 19:39:44 +00002224Windows changes
2225
2226- Build procedure: the zlib project is built in a different way that
2227 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002228 the zlib binary used. See PCbuild\readme.txt for details. Your old
2229 zlib-related directories can be deleted; you'll need to download fresh
2230 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002231
Tim Peters9ea17ac2001-02-02 05:57:15 +00002232- Build: New subproject _test for the benefit of test_capi.py (see above).
2233
Tim Petersb16c56f2001-02-02 21:24:51 +00002234- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2235 interface to some Python compiler internals).
2236
2237- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002238 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002239
Tim Petersa3a3a032000-11-30 05:22:44 +00002240What's New in Python 2.1 alpha 1?
2241=================================
2242
2243Core language, builtins, and interpreter
2244
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002245- There is a new Unicode companion to the PyObject_Str() API
2246 called PyObject_Unicode(). It behaves in the same way as the
2247 former, but assures that the returned value is an Unicode object
2248 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002249
Guido van Rossumf98eda02001-01-17 15:54:45 +00002250- The comparison operators support "rich comparison overloading" (PEP
2251 207). C extension types can provide a rich comparison function in
2252 the new tp_richcompare slot in the type object. The cmp() function
2253 and the C function PyObject_Compare() first try the new rich
2254 comparison operators before trying the old 3-way comparison. There
2255 is also a new C API PyObject_RichCompare() (which also falls back on
2256 the old 3-way comparison, but does not constrain the outcome of the
2257 rich comparison to a Boolean result).
2258
2259 The rich comparison function takes two objects (at least one of
2260 which is guaranteed to have the type that provided the function) and
2261 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2262 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2263 object, which may be NotImplemented (in which case the tp_compare
2264 slot function is used as a fallback, if defined).
2265
2266 Classes can overload individual comparison operators by defining one
2267 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002268 __ge__. There are no explicit "reflected argument" versions of
2269 these; instead, __lt__ and __gt__ are each other's reflection,
2270 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2271 reflection (similar at the C level). No other implications are
2272 made; in particular, Python does not assume that == is the Boolean
2273 inverse of !=, or that < is the Boolean inverse of >=. This makes
2274 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002275
2276 Classes or types that want to implement (in)equality tests but not
2277 the ordering operators (i.e. unordered types) should implement ==
2278 and !=, and raise an error for the ordering operators.
2279
Guido van Rossuma88479f2001-01-18 14:28:08 +00002280 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002281 Boolean; e.g. a matrix type might want to return a matrix of bits
2282 for A < B, giving elementwise comparisons. Such types should ensure
2283 that any interpretation of their value in a Boolean context raises
2284 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2285 at the C level) to always raise an exception.
2286
Guido van Rossuma88479f2001-01-18 14:28:08 +00002287- Complex numbers use rich comparisons to define == and != but raise
2288 an exception for <, <=, > and >=. Unfortunately, this also means
2289 that cmp() of two complex numbers raises an exception when the two
2290 numbers differ. Since it is not mathematically meaningful to compare
2291 complex numbers except for equality, I hope that this doesn't break
2292 too much code.
2293
Tim Peters3389f192001-02-18 08:48:49 +00002294- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002295 not defined by the language, other than that it's arbitrary but
2296 consistent (see the Reference Manual). An implementation detail changed
2297 in 2.1a1 such that None now compares less than any other object. Code
2298 relying on this new behavior (like code that relied on the previous
2299 behavior) does so at its own risk.
2300
Barry Warsaw573b5412001-01-15 20:43:18 +00002301- Functions and methods now support getting and setting arbitrarily
2302 named attributes (PEP 232). Functions have a new __dict__
2303 (a.k.a. func_dict) which hold the function attributes. Methods get
2304 and set attributes on their underlying im_func. It is a TypeError
2305 to set an attribute on a bound method.
2306
Guido van Rossum051e3352001-01-15 19:11:10 +00002307- The xrange() object implementation has been improved so that
2308 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2309 limitation that in this case len(xrange(sys.maxint)) can't be
2310 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2311 work fine as long as the index i doesn't actually reach 2**31.
2312 (Python uses regular ints for sequence and string indices; fixing
2313 that is much more work.)
2314
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002315- Two changes to from...import:
2316
Guido van Rossumba381232001-02-03 15:06:40 +00002317 1) "from M import X" now works even if (after loading module M)
2318 sys.modules['M'] is not a real module; it's basically a getattr()
2319 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002320
2321 2) "from M import *" now looks for M.__all__ to decide which names to
2322 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2323 filters out names starting with '_' as before. Whether or not
2324 __all__ exists, there's no restriction on the type of M.
2325
Guido van Rossumf61f1662001-01-10 20:13:55 +00002326- File objects have a new method, xreadlines(). This is the fastest
2327 way to iterate over all lines in a file:
2328
2329 for line in file.xreadlines():
2330 ...do something to line...
2331
2332 See the xreadlines module (mentioned below) for how to do this for
2333 other file-like objects.
2334
2335- Even if you don't use file.xreadlines(), you may expect a speedup on
2336 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002337 quite a bit in platform-specific ways: on systems (like Linux) that
2338 support flockfile(), getc_unlocked(), and funlockfile(), those are
2339 used by default. On systems (like Windows) without getc_unlocked(),
2340 a complicated (but still thread-safe) method using fgets() is used by
2341 default.
2342
Tim Petersd52269b2001-01-25 06:23:18 +00002343 You can force use of the fgets() method by #define'ing
2344 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002345 getc_unlocked()).
2346
Tim Petersd52269b2001-01-25 06:23:18 +00002347 You can force fgets() not to be used by #define'ing
2348 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002349 test_bufio.py fails -- and let us know if it does!).
2350
2351- In addition, the fileinput module, while still slower than the other
2352 methods on most platforms, has been sped up too, by using
2353 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002354
2355- Support for run-time warnings has been added, including a new
2356 command line option (-W) to specify the disposition of warnings.
2357 See the description of the warnings module below.
2358
2359- Extensive changes have been made to the coercion code. This mostly
2360 affects extension modules (which can now implement mixed-type
2361 numerical operators without having to use coercion), but
2362 occasionally, in boundary cases the coercion semantics have changed
2363 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002364 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002365 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002366 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002367
Guido van Rossumf98eda02001-01-17 15:54:45 +00002368- In connection with the coercion changes, a new built-in singleton
2369 object, NotImplemented is defined. This can be returned for
2370 operations that wish to indicate they are not implemented for a
2371 particular combination of arguments. From C, this is
2372 Py_NotImplemented.
2373
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002374- The interpreter accepts now bytecode files on the command line even
2375 if they do not have a .pyc or .pyo extension. On Linux, after executing
2376
Martin v. Löwise214baa2001-02-04 22:37:56 +00002377import imp,sys,string
2378magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2379reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2380open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002381
2382 any byte code file can be used as an executable (i.e. as an argument
2383 to execve(2)).
2384
Tim Peters9940b802000-12-01 07:59:35 +00002385- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002386 character. In 1.6 and earlier, they never produced a sign,
2387 and raised an error if the value of the long was too large
2388 to fit in a Python int. In 2.0, they produced a sign if and
2389 only if too large to fit in an int. This was inconsistent
2390 across platforms (because the size of an int varies across
2391 platforms), and inconsistent with hex() and oct(). Example:
2392
2393 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002394 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002395 'ffffffbe' # in 2.0 and before, on 32-bit machines
2396 >>> hex(-0x42L)
2397 '-0x42L' # in all versions of Python
2398
Tim Peters9940b802000-12-01 07:59:35 +00002399 The behavior of %d formats for negative Python longs remains
2400 the same as in 2.0 (although in 1.6 and before, they raised
2401 an error if the long didn't fit in a Python int).
2402
2403 %u formats don't make sense for Python longs, but are allowed
2404 and treated the same as %d in 2.1. In 2.0, a negative long
2405 formatted via %u produced a sign if and only if too large to
2406 fit in an int. In 1.6 and earlier, a negative long formatted
2407 via %u raised an error if it was too big to fit in an int.
2408
Guido van Rossum3661d392000-12-12 22:10:31 +00002409- Dictionary objects have an odd new method, popitem(). This removes
2410 an arbitrary item from the dictionary and returns it (in the form of
2411 a (key, value) pair). This can be useful for algorithms that use a
2412 dictionary as a bag of "to do" items and repeatedly need to pick one
2413 item. Such algorithms normally end up running in quadratic time;
2414 using popitem() they can usually be made to run in linear time.
2415
Tim Peters36cdad12000-12-29 02:06:45 +00002416Standard library
2417
Thomas Woutersfe385252001-01-19 23:16:56 +00002418- In the time module, the time argument to the functions strftime,
2419 localtime, gmtime, asctime and ctime is now optional, defaulting to
2420 the current time (in the local timezone).
2421
Guido van Rossumda91f222001-01-15 16:36:08 +00002422- The ftplib module now defaults to passive mode, which is deemed a
2423 more useful default given that clients are often inside firewalls
2424 these days. Note that this could break if ftplib is used to connect
2425 to a *server* that is inside a firewall, from outside; this is
2426 expected to be a very rare situation. To fix that, you can call
2427 ftp.set_pasv(0).
2428
Martin v. Löwis10a27872001-01-13 09:54:41 +00002429- The module site now treats .pth files not only for path configuration,
2430 but also supports extensions to the initialization code: Lines starting
2431 with import are executed.
2432
Guido van Rossumf61f1662001-01-10 20:13:55 +00002433- There's a new module, warnings, which implements a mechanism for
2434 issuing and filtering warnings. There are some new built-in
2435 exceptions that serve as warning categories, and a new command line
2436 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2437 turns warnings into errors). warnings.warn(message[, category])
2438 issues a warning message; this can also be called from C as
2439 PyErr_Warn(category, message).
2440
2441- A new module xreadlines was added. This exports a single factory
2442 function, xreadlines(). The intention is that this code is the
2443 absolutely fastest way to iterate over all lines in an open
2444 file(-like) object:
2445
2446 import xreadlines
2447 for line in xreadlines.xreadlines(file):
2448 ...do something to line...
2449
2450 This is equivalent to the previous the speed record holder using
2451 file.readlines(sizehint). Note that if file is a real file object
2452 (as opposed to a file-like object), this is equivalent:
2453
2454 for line in file.xreadlines():
2455 ...do something to line...
2456
Tim Peters36cdad12000-12-29 02:06:45 +00002457- The bisect module has new functions bisect_left, insort_left,
2458 bisect_right and insort_right. The old names bisect and insort
2459 are now aliases for bisect_right and insort_right. XXX_right
2460 and XXX_left methods differ in what happens when the new element
2461 compares equal to one or more elements already in the list: the
2462 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002463 right. Code that doesn't care where equal elements end up should
2464 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002465
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002466- The new curses.panel module wraps the panel library that forms part
2467 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2468
Guido van Rossumf61f1662001-01-10 20:13:55 +00002469- The SocketServer module now sets the allow_reuse_address flag by
2470 default in the TCPServer class.
2471
2472- A new function, sys._getframe(), returns the stack frame pointer of
2473 the caller. This is intended only as a building block for
2474 higher-level mechanisms such as string interpolation.
2475
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002476- The pyexpat module supports a number of new handlers, which are
2477 available only in expat 1.2. If invocation of a callback fails, it
2478 will report an additional frame in the traceback. Parser objects
2479 participate now in garbage collection. If expat reports an unknown
2480 encoding, pyexpat will try to use a Python codec; that works only
2481 for single-byte charsets. The parser type objects is exposed as
2482 XMLParserObject.
2483
2484- xml.dom now offers standard definitions for symbolic node type and
2485 exception code constants, and a hierarchy of DOM exceptions. minidom
2486 was adjusted to use them.
2487
2488- The conformance of xml.dom.minidom to the DOM specification was
2489 improved. It detects a number of additional error cases; the
2490 previous/next relationship works even when the tree is modified;
2491 Node supports the normalize() method; NamedNodeMap, DocumentType and
2492 DOMImplementation classes were added; Element supports the
2493 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2494 method.
2495
Guido van Rossumf61f1662001-01-10 20:13:55 +00002496Build issues
2497
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002498- For Unix (and Unix-compatible) builds, configuration and building of
2499 extension modules is now greatly automated. Rather than having to
2500 edit the Modules/Setup file to indicate which modules should be
2501 built and where their include files and libraries are, a
2502 distutils-based setup.py script now takes care of building most
2503 extension modules. All extension modules built this way are built
2504 as shared libraries. Only a few modules that must be linked
2505 statically are still listed in the Setup file; you won't need to
2506 edit their configuration.
2507
2508- Python should now build out of the box on Cygwin. If it doesn't,
2509 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002510
2511- Python now always uses its own (renamed) implementation of getopt()
2512 -- there's too much variation among C library getopt()
2513 implementations.
2514
2515- C++ compilers are better supported; the CXX macro is always set to a
2516 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002517
Tim Petersd92dfe02000-12-12 01:18:41 +00002518Windows changes
2519
2520- select module: By default under Windows, a select() call
2521 can specify no more than 64 sockets. Python now boosts
2522 this Microsoft default to 512. If you need even more than
2523 that, see the MS docs (you'll need to #define FD_SETSIZE
2524 and recompile Python from source).
2525
Guido van Rossumf61f1662001-01-10 20:13:55 +00002526- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2527 subdirectory is no more!
2528
Tim Petersa3a3a032000-11-30 05:22:44 +00002529
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002530What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002531=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002532
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002533Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002534changes are in the file HISTORY. If you are making the jump directly
2535from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2536HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002537
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002538Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2539the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2540http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002541
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002542--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002543
2544======================================================================
2545
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002546What's new in 2.0 (since release candidate 1)?
2547==============================================
2548
2549Standard library
2550
2551- The copy_reg module was modified to clarify its intended use: to
2552 register pickle support for extension types, not for classes.
2553 pickle() will raise a TypeError if it is passed a class.
2554
2555- Fixed a bug in gettext's "normalize and expand" code that prevented
2556 it from finding an existing .mo file.
2557
2558- Restored support for HTTP/0.9 servers in httplib.
2559
Tim Peters989b7b92000-10-16 20:24:53 +00002560- The math module was changed to stop raising OverflowError in case of
2561 underflow, and return 0 instead in underflow cases. Whether Python
2562 used to raise OverflowError in case of underflow was platform-
2563 dependent (it did when the platform math library set errno to ERANGE
2564 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002565
2566- Fixed a bug in StringIO that occurred when the file position was not
2567 at the end of the file and write() was called with enough data to
2568 extend past the end of the file.
2569
2570- Fixed a bug that caused Tkinter error messages to get lost on
2571 Windows. The bug was fixed by replacing direct use of
2572 interp->result with Tcl_GetStringResult(interp).
2573
2574- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2575 redirect response.
2576
2577- Several changes were made to distutils: Some debugging code was
2578 removed from util. Fixed the installer used when an external zip
2579 program (like WinZip) is not found; the source code for this
2580 installer is in Misc/distutils. check_lib() was modified to behave
2581 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2582 test for whether installed modules are on sys.path was changed to
2583 use both normcase() and normpath().
2584
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002585- Several minor bugs were fixed in the xml package (the minidom,
2586 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002587
2588- The regression test driver (regrtest.py) behavior when invoked with
2589 -l changed: It now reports a count of objects that are recognized as
2590 garbage but not freed by the garbage collector.
2591
Tim Peters989b7b92000-10-16 20:24:53 +00002592- The regression test for the math module was changed to test
2593 exceptional behavior when the test is run in verbose mode. Python
2594 cannot yet guarantee consistent exception behavior across platforms,
2595 so the exception part of test_math is run only in verbose mode, and
2596 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002597
2598Internals
2599
2600- PyOS_CheckStack() has been disabled on Win64, where it caused
2601 test_sre to fail.
2602
2603Build issues
2604
2605- Changed compiler flags, so that gcc is always invoked with -Wall and
2606 -Wstrict-prototypes. Users compiling Python with GCC should see
2607 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002608 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002609 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002610
Tim Petersa3a3a032000-11-30 05:22:44 +00002611- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002612
2613Tools and other miscellany
2614
2615- The compiler in Tools/compiler was updated to support the new
2616 language features introduced in 2.0: extended print statement, list
2617 comprehensions, and augmented assignments. The new compiler should
2618 also be backwards compatible with Python 1.5.2; the compiler will
2619 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002620 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002621
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002622What's new in 2.0 release candidate 1 (since beta 2)?
2623=====================================================
2624
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002625What is release candidate 1?
2626
2627We believe that release candidate 1 will fix all known bugs that we
2628intend to fix for the 2.0 final release. This release should be a bit
2629more stable than the previous betas. We would like to see even more
2630widespread testing before the final release, so we are producing this
2631release candidate. The final release will be exactly the same unless
2632any show-stopping (or brown bag) bugs are found by testers of the
2633release candidate.
2634
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002635All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002636to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002637
2638Core language, builtins, and interpreter
2639
2640- A bug that caused crashes when __coerce__ was used with augmented
2641 assignment, e.g. +=, was fixed.
2642
2643- Raise ZeroDivisionError when raising zero to a negative number,
2644 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2645 power operator and the result of math.pow(0.0, -2.0) will vary by
2646 platform. On Linux, it raises a ValueError.
2647
2648- A bug in Unicode string interpolation was fixed that occasionally
2649 caused errors with formats including "%%". For example, the
2650 following expression "%% %s" % u"abc" no longer raises a TypeError.
2651
2652- Compilation of deeply nested expressions raises MemoryError instead
2653 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2654
2655- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2656 rendering them useless. They are now written in binary mode again.
2657
2658Standard library
2659
2660- Keyword arguments are now accepted for most pattern and match object
2661 methods in SRE, the standard regular expression engine.
2662
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002663- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002664 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002665
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002666- Several bugs in the Unicode handling and error handling in _tkinter
2667 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002668
2669- Fix memory management errors in Merge() and Tkapp_Call() routines.
2670
2671- Several changes were made to cStringIO to make it compatible with
2672 the file-like object interface and with StringIO. If operations are
2673 performed on a closed object, an exception is raised. The truncate
2674 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002675 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002676
2677- There were many changes made to the linuxaudiodev module and its
2678 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002679 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002680
2681 Note that this module is named poorly, because it should work
2682 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002683 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002684
2685 The module now raises exceptions when errors occur instead of
2686 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2687 audio) and defines a getptr() method that calls the
2688 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2689
2690- The library_version attribute, introduced in an earlier beta, was
2691 removed because it can not be supported with early versions of the C
2692 readline library, which provides no way to determine the version at
2693 compile-time.
2694
2695- The binascii module is now enabled on Win64.
2696
Tim Peters46446d62000-10-09 21:19:31 +00002697- tokenize.py no longer suffers "recursion depth" errors when parsing
2698 programs with very long string literals.
2699
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002700Internals
2701
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002702- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002703 which is called when the interpreter starts up to determine where
2704 the standard library is installed. These vulnerabilities affect all
2705 previous versions of Python and can be exploited by setting very
2706 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2707 setuid Python script, although use of the wrapper in
2708 Misc/setuid-prog.c will eliminate the vulnerability.
2709
2710- Fixed garbage collection bugs in instance creation that were
2711 triggered when errors occurred during initialization. The solution,
2712 applied in cPickle and in PyInstance_New(), is to call
2713 PyObject_GC_Init() after the initialization of the object's
2714 container attributes is complete.
2715
2716- pyexpat adds definitions of PyModule_AddStringConstant and
2717 PyModule_AddObject if the Python version is less than 2.0, which
2718 provides compatibility with PyXML on Python 1.5.2.
2719
2720- If the platform has a bogus definition for LONG_BIT (the number of
2721 bits in a long), an error will be reported at compile time.
2722
2723- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2724 collection crashes and possibly other, unreported crashes.
2725
2726- Fixed a memory leak in _PyUnicode_Fini().
2727
2728Build issues
2729
2730- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002731 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002732 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002733
2734- The mmap.PAGESIZE constant is now initialized using sysconf when
2735 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2736
2737- The md5 file should now compile on all platforms.
2738
2739- The select module now compiles on platforms that do not define
2740 POLLRDNORM and related constants.
2741
2742- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002743 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002744
Jeremy Hylton10921202000-10-09 18:34:12 +00002745- BeOS: A number of changes were made to the build and installation
2746 process. ar-fake now operates on a directory of object files.
2747 dl_export.h is gone, and its macros now appear on the mwcc command
2748 line during build on PPC BeOS.
2749
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002750- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002751 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002752
2753- Cygwin: Support for shared libraries, Tkinter, and sockets.
2754
2755- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2756
2757Tools and other miscellany
2758
2759- Removed debugging prints from main used with freeze.
2760
Tim Peters46446d62000-10-09 21:19:31 +00002761- IDLE auto-indent no longer crashes when it encounters Unicode
2762 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002763
2764What's new in 2.0 beta 2 (since beta 1)?
2765========================================
2766
2767Core language, builtins, and interpreter
2768
Tim Peters482c0212000-09-26 06:33:09 +00002769- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002770 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002771
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002772- Add -h and -V command line options to print the usage message and
2773 Python version number and exit immediately.
2774
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002775- eval() and exec accept Unicode objects as code parameters.
2776
2777- getattr() and setattr() now also accept Unicode objects for the
2778 attribute name, which are converted to strings using the default
2779 encoding before lookup.
2780
2781- Multiplication on string and Unicode now does proper bounds
2782 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2783 string is too long."
2784
2785- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002786 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002787
Jeremy Hylton1b618592000-09-26 05:32:36 +00002788
2789Standard library and extensions
2790
Guido van Rossum5b08f132001-04-16 02:05:23 +00002791- socket module: the OpenSSL code now adds support for RAND_status()
2792 and EGD (Entropy Gathering Device).
2793
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002794- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002795 argument checking; it still takes no arguments.
2796
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002797- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002798
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002799- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002800
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002801- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002802
2803- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002804 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002805
2806- copy: Copy Unicode objects atomically.
2807
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002808- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002809
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002810- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002811
Fred Drake67233bc2000-09-26 16:40:27 +00002812- dbm: Add get() and setdefault() methods to dbm object. Add constant
2813 `library' to module that names the library used. Added doc strings
2814 and method names to error messages. Uses configure to determine
2815 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2816 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002817
2818- distutils: Update to version 0.9.3.
2819
2820- dl: Add several dl.RTLD_ constants.
2821
2822- fpectl: Now supported on FreeBSD.
2823
2824- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2825 found by the collector will be saved in gc.garbage. This is useful
2826 for debugging a program that creates reference cycles.
2827
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002828- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002829 of HTTP class. Do not close socket on zero-length response. Do not
2830 crash when server sends invalid content-length header.
2831
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002832- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002833
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002834- marshal: When reading a short, sign-extend on platforms where shorts
2835 are bigger than 16 bits. When reading a long, repair the unportable
2836 sign extension that was being done for 64-bit machines. (It assumed
2837 that signed right shift sign-extends.)
2838
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002839- operator: Add contains(), invert(), __invert__() as aliases for
2840 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002841
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002842- os: Add support for popen2() and popen3() on all platforms where
2843 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002844
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002845- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002846 clicking on a file in Explorer (or passing the file name to the
2847 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002848
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002849- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002850 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002851
2852- pickle: Now raises ValueError when an invalid pickle that contains
2853 a non-string repr where a string repr was expected. This behavior
2854 matches cPickle.
2855
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002856- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002857
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002858- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002859
2860- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002861 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002862 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002863
2864- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002865 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002866
2867- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002868 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002869 few cycles during startup since the first call to
2870 setdefaultencoding() will initialize the codec registry and the
2871 encodings package.
2872
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002873- socket: Support for size hint in readlines() method of object returned
2874 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002875
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002876- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002877 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002878 is followed by whitespace.
2879
Tim Petersa3a3a032000-11-30 05:22:44 +00002880- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002881
2882- struct: Check ranges for bytes and shorts.
2883
2884- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002885 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002886
2887- Tkinter: Image objects are now guaranteed to have unique ids. Set
2888 event.delta to zero if Tk version doesn't support mousewheel.
2889 Removed some debugging prints.
2890
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002891- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002892
Fred Drake67233bc2000-09-26 16:40:27 +00002893- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002894 which works around a bug in Norton AntiVirus 2000 that leads directly
2895 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002896
2897- xml: New version detection code allows PyXML to override standard
2898 XML package if PyXML version is greater than 0.6.1.
2899
Fred Drake64bb3802000-09-26 16:21:35 +00002900- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2901 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2902 tree only for nodes which are sufficiently interesting to a specific
2903 application. Does not provide the HTML-specific extensions. Still
2904 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002905
Fred Drake64bb3802000-09-26 16:21:35 +00002906- xml.sax: SAX 2 support for Python, including all the handler
2907 interfaces needed to process XML 1.0 compliant XML. Some
2908 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002909
Fred Drake64bb3802000-09-26 16:21:35 +00002910- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2911 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002912
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002913
Jeremy Hylton1b618592000-09-26 05:32:36 +00002914C API
2915
2916- Add three new convenience functions for module initialization --
2917 PyModule_AddObject(), PyModule_AddIntConstant(), and
2918 PyModule_AddStringConstant().
2919
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002920- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002921 removed and add #error to Python.h if NULL isn't defined after
2922 #include of stdio.h.
2923
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002924- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002925 backwards compatibility (at the source level) with old extensions.
2926
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002927- A wrapper API was added for signal() and sigaction(). Instead of
2928 either function, always use PyOS_getsig() to get a signal handler
2929 and PyOS_setsig() to set one. A new convenience typedef
2930 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002931
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002932- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002933 internal data buffer and size of a string object -- or the default
2934 encoded version of a Unicode object.
2935
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002936- PyString_Size() and PyString_AsString() accept Unicode objects.
2937
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002938- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002939 exists). INT_MAX and LONG_MAX will always be defined, even if
2940 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002941
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002942- PyFloat_FromString takes a second argument, pend, that was
2943 effectively useless. It is now officially useless but preserved for
2944 backwards compatibility. If the pend argument is not NULL, *pend is
2945 set to NULL.
2946
2947- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2948 for the attribute name. See note on getattr() above.
2949
2950- A few bug fixes to argument processing for Unicode.
2951 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2952 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2953 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002954 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002955
2956- Py_BuildValue accepts B format (for bgen-generated code).
2957
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002958
Jeremy Hylton1b618592000-09-26 05:32:36 +00002959Internals
2960
2961- On Unix, fix code for finding Python installation directory so that
2962 it works when argv[0] is a relative path.
2963
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002964- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002965 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002966 rather than by generating a copy of the object.
2967
Tim Peters482c0212000-09-26 06:33:09 +00002968- Several of the internal Unicode tables are much smaller now, and
2969 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002970
Jeremy Hylton97693b02000-09-26 17:42:51 +00002971- In the garbage collector: Fixed bug in collection of tuples. Fixed
2972 bug that caused some instances to be removed from the container set
2973 while they were still live. Fixed parsing in gc.set_debug() for
2974 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002975
2976- Fixed refcount problem in instance deallocation that only occurred
2977 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2978
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002979- On Windows, getpythonregpath is now protected against null data in
2980 registry key.
2981
2982- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002983 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002984
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002985
Jeremy Hylton1b618592000-09-26 05:32:36 +00002986Build and platform-specific issues
2987
2988- Better support of GNU Pth via --with-pth configure option.
2989
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002990- Python/C API now properly exposed to dynamically-loaded extension
2991 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002992
2993- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2994 Don't define MS_SYNC to be zero when it is undefined. Added missing
2995 prototypes in posixmodule.c.
2996
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002997- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002998 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002999
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003000- Fix largefile support on older NetBSD systems and OpenBSD by adding
3001 define for TELL64.
3002
3003
3004Tools and other miscellany
3005
3006- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3007
3008- freeze: The modulefinder now works with 2.0 opcodes.
3009
Tim Petersa3a3a032000-11-30 05:22:44 +00003010- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003011 Move hackery of sys.argv until after the Tk instance has been
3012 created, which allows the application-specific Tkinter
3013 initialization to be executed if present; also pass an explicit
3014 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003015
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016
3017What's new in 2.0 beta 1?
3018=========================
3019
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003020Source Incompatibilities
3021------------------------
3022
3023None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3024such as single-argument append(), connect() and bind(), and changes to
3025str(long) and repr(float).
3026
3027
3028Binary Incompatibilities
3029------------------------
3030
3031- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3032with Python 2.0; these extensions will have to be rebuilt for Python
30332.0.
3034
3035- On Windows, attempting to import a third party extension built for
3036Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3037can do about this. Check your PYTHONPATH environment variable!
3038
3039- Python bytecode files (*.pyc and *.pyo) are not compatible between
3040releases.
3041
3042
3043Overview of Changes Since 1.6
3044-----------------------------
3045
3046There are many new modules (including brand new XML support through
3047the xml package, and i18n support through the gettext module); a list
3048of all new modules is included below. Lots of bugs have been fixed.
3049
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003050The process for making major new changes to the language has changed
3051since Python 1.6. Enhancements must now be documented by a Python
3052Enhancement Proposal (PEP) before they can be accepted.
3053
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003054There are several important syntax enhancements, described in more
3055detail below:
3056
3057 - Augmented assignment, e.g. x += 1
3058
3059 - List comprehensions, e.g. [x**2 for x in range(10)]
3060
3061 - Extended import statement, e.g. import Module as Name
3062
3063 - Extended print statement, e.g. print >> file, "Hello"
3064
3065Other important changes:
3066
3067 - Optional collection of cyclical garbage
3068
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003069Python Enhancement Proposal (PEP)
3070---------------------------------
3071
3072PEP stands for Python Enhancement Proposal. A PEP is a design
3073document providing information to the Python community, or describing
3074a new feature for Python. The PEP should provide a concise technical
3075specification of the feature and a rationale for the feature.
3076
3077We intend PEPs to be the primary mechanisms for proposing new
3078features, for collecting community input on an issue, and for
3079documenting the design decisions that have gone into Python. The PEP
3080author is responsible for building consensus within the community and
3081documenting dissenting opinions.
3082
3083The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003084
3085Augmented Assignment
3086--------------------
3087
3088This must have been the most-requested feature of the past years!
3089Eleven new assignment operators were added:
3090
Guido van Rossume905e952000-09-05 12:42:46 +00003091 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003092
3093For example,
3094
3095 A += B
3096
3097is similar to
3098
3099 A = A + B
3100
3101except that A is evaluated only once (relevant when A is something
3102like dict[index].attr).
3103
3104However, if A is a mutable object, A may be modified in place. Thus,
3105if A is a number or a string, A += B has the same effect as A = A+B
3106(except A is only evaluated once); but if a is a list, A += B has the
3107same effect as A.extend(B)!
3108
3109Classes and built-in object types can override the new operators in
3110order to implement the in-place behavior; the not-in-place behavior is
3111used automatically as a fallback when an object doesn't implement the
3112in-place behavior. For classes, the method name is derived from the
3113method name for the corresponding not-in-place operator by inserting
3114an 'i' in front of the name, e.g. __iadd__ implements in-place
3115__add__.
3116
3117Augmented assignment was implemented by Thomas Wouters.
3118
3119
3120List Comprehensions
3121-------------------
3122
3123This is a flexible new notation for lists whose elements are computed
3124from another list (or lists). The simplest form is:
3125
3126 [<expression> for <variable> in <sequence>]
3127
Guido van Rossum56db0952000-09-06 23:34:25 +00003128For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003129This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003130
3131You can also add a condition:
3132
3133 [<expression> for <variable> in <sequence> if <condition>]
3134
3135For example, [w for w in words if w == w.lower()] would yield the list
3136of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003137than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003138
3139You can also have nested for loops and more than one 'if' clause. For
3140example, here's a function that flattens a sequence of sequences::
3141
3142 def flatten(seq):
3143 return [x for subseq in seq for x in subseq]
3144
3145 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3146
3147This prints
3148
3149 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3150
3151List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003152Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003153
3154
3155Extended Import Statement
3156-------------------------
3157
3158Many people have asked for a way to import a module under a different
3159name. This can be accomplished like this:
3160
3161 import foo
3162 bar = foo
3163 del foo
3164
3165but this common idiom gets old quickly. A simple extension of the
3166import statement now allows this to be written as follows:
3167
3168 import foo as bar
3169
3170There's also a variant for 'from ... import':
3171
3172 from foo import bar as spam
3173
3174This also works with packages; e.g. you can write this:
3175
3176 import test.regrtest as regrtest
3177
3178Note that 'as' is not a new keyword -- it is recognized only in this
3179context (this is only possible because the syntax for the import
3180statement doesn't involve expressions).
3181
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003182Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003183
3184
3185Extended Print Statement
3186------------------------
3187
3188Easily the most controversial new feature, this extension to the print
3189statement adds an option to make the output go to a different file
3190than the default sys.stdout.
3191
3192For example, to write an error message to sys.stderr, you can now
3193write:
3194
3195 print >> sys.stderr, "Error: bad dog!"
3196
3197As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003198evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003199
3200 print >> None, "Hello world"
3201
3202is equivalent to
3203
3204 print "Hello world"
3205
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003206Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003207
3208
3209Optional Collection of Cyclical Garbage
3210---------------------------------------
3211
3212Python is now equipped with a garbage collector that can hunt down
3213cyclical references between Python objects. It's no replacement for
3214reference counting; in fact, it depends on the reference counts being
3215correct, and decides that a set of objects belong to a cycle if all
3216their reference counts can be accounted for from their references to
3217each other. This devious scheme was first proposed by Eric Tiedemann,
3218and brought to implementation by Neil Schemenauer.
3219
3220There's a module "gc" that lets you control some parameters of the
3221garbage collection. There's also an option to the configure script
3222that lets you enable or disable the garbage collection. In 2.0b1,
3223it's on by default, so that we (hopefully) can collect decent user
3224experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003225performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003226off by default in the final 2.0 release.
3227
3228
3229Smaller Changes
3230---------------
3231
3232A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3233map(None, seq1, seq2, ...) when the sequences have the same length;
3234i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3235the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003236zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003237
3238sys.version_info is a tuple (major, minor, micro, level, serial).
3239
3240Dictionaries have an odd new method, setdefault(key, default).
3241dict.setdefault(key, default) returns dict[key] if it exists; if not,
3242it sets dict[key] to default and returns that value. Thus:
3243
3244 dict.setdefault(key, []).append(item)
3245
3246does the same work as this common idiom:
3247
3248 if not dict.has_key(key):
3249 dict[key] = []
3250 dict[key].append(item)
3251
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003252There are two new variants of SyntaxError that are raised for
3253indentation-related errors: IndentationError and TabError.
3254
3255Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3256escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003257
3258The limits on the size of expressions and file in Python source code
3259have been raised from 2**16 to 2**32. Previous versions of Python
3260were limited because the maximum argument size the Python VM accepted
3261was 2**16. This limited the size of object constructor expressions,
3262e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3263limit was raised thanks to a patch by Charles Waldman that effectively
3264fixes the problem. It is now much more likely that you will be
3265limited by available memory than by an arbitrary limit in Python.
3266
3267The interpreter's maximum recursion depth can be modified by Python
3268programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3269limit is the maximum number of recursive calls that can be made by
3270Python code. The limit exists to prevent infinite recursion from
3271overflowing the C stack and causing a core dump. The default value is
32721000. The maximum safe value for a particular platform can be found
3273by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003274
3275New Modules and Packages
3276------------------------
3277
3278atexit - for registering functions to be called when Python exits.
3279
3280imputil - Greg Stein's alternative API for writing custom import
3281hooks.
3282
3283pyexpat - an interface to the Expat XML parser, contributed by Paul
3284Prescod.
3285
3286xml - a new package with XML support code organized (so far) in three
3287subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3288would fill a volume. There's a special feature whereby a
3289user-installed package named _xmlplus overrides the standard
3290xmlpackage; this is intended to give the XML SIG a hook to distribute
3291backwards-compatible updates to the standard xml package.
3292
3293webbrowser - a platform-independent API to launch a web browser.
3294
3295
Guido van Rossume905e952000-09-05 12:42:46 +00003296Changed Modules
3297---------------
3298
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003299array -- new methods for array objects: count, extend, index, pop, and
3300remove
3301
3302binascii -- new functions b2a_hex and a2b_hex that convert between
3303binary data and its hex representation
3304
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003305calendar -- Many new functions that support features including control
3306over which day of the week is the first day, returning strings instead
3307of printing them. Also new symbolic constants for days of week,
3308e.g. MONDAY, ..., SUNDAY.
3309
3310cgi -- FieldStorage objects have a getvalue method that works like a
3311dictionary's get method and returns the value attribute of the object.
3312
3313ConfigParser -- The parser object has new methods has_option,
3314remove_section, remove_option, set, and write. They allow the module
3315to be used for writing config files as well as reading them.
3316
3317ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003318optionally support the RFC 959 REST command.
3319
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003320gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003321
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003322httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3323the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003324
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003325locale -- implement getdefaultlocale for Win32 and Macintosh
3326
3327marshal -- no longer dumps core when marshaling deeply nested or
3328recursive data structures
3329
3330os -- new functions isatty, seteuid, setegid, setreuid, setregid
3331
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003332os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3333support under Unix.
3334
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003335os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003336
3337os.path -- fix semantics of os.path.commonprefix
3338
3339smtplib -- support for sending very long messages
3340
3341socket -- new function getfqdn()
3342
3343readline -- new functions to read, write and truncate history files.
3344The readline section of the library reference manual contains an
3345example.
3346
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003347select -- add interface to poll system call
3348
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003349shutil -- new copyfileobj function
3350
3351SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3352HTTP server.
3353
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003354Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003355
3356urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003357e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003358
3359whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003360
3361
3362Obsolete Modules
3363----------------
3364
3365None. However note that 1.6 made a whole slew of modules obsolete:
3366stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3367poly, zmod, strop, util, whatsound.
3368
3369
3370Changed, New, Obsolete Tools
3371----------------------------
3372
Tim Peters8b092332000-09-05 20:15:25 +00003373None.
Guido van Rossume905e952000-09-05 12:42:46 +00003374
3375
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003376C-level Changes
3377---------------
3378
3379Several cleanup jobs were carried out throughout the source code.
3380
3381All C code was converted to ANSI C; we got rid of all uses of the
3382Py_PROTO() macro, which makes the header files a lot more readable.
3383
3384Most of the portability hacks were moved to a new header file,
3385pyport.h; several other new header files were added and some old
3386header files were removed, in an attempt to create a more rational set
3387of header files. (Few of these ever need to be included explicitly;
3388they are all included by Python.h.)
3389
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003390Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003391and Win64, especially for the new Intel Itanium processor. Mick also
3392added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003393
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003394The C APIs to return an object's size have been update to consistently
3395use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3396previous versions, the abstract interfaces used PyXXX_Length and the
3397concrete interfaces used PyXXX_Size. The old names,
3398e.g. PyObject_Length, are still available for backwards compatibility
3399at the API level, but are deprecated.
3400
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003401The PyOS_CheckStack function has been implemented on Windows by
3402Fredrik Lundh. It prevents Python from failing with a stack overflow
3403on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003404
3405The GC changes resulted in creation of two new slots on object,
3406tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003407the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003408
3409The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003410C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003411
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003412PyErr_Format has been updated to automatically calculate the size of
3413the buffer needed to hold the formatted result string. This change
3414prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003415
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003416New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003417
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003418PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3419that are the same as their non-Ex counterparts except they take an
3420extra flag argument that tells them to close the file when done.
3421
3422XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003423
Tim Peters8b092332000-09-05 20:15:25 +00003424
3425Windows Changes
3426---------------
3427
3428New popen2/popen3/peopen4 in os module (see Changed Modules above).
3429
3430os.popen is much more usable on Windows 95 and 98. See Microsoft
3431Knowledge Base article Q150956. The Win9x workaround described there
3432is implemented by the new w9xpopen.exe helper in the root of your
3433Python installation. Note that Python uses this internally; it is not
3434a standalone program.
3435
3436Administrator privileges are no longer required to install Python
3437on Windows NT or Windows 2000. If you have administrator privileges,
3438Python's registry info will be written under HKEY_LOCAL_MACHINE.
3439Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003440under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003441uses of Python, but will prevent some advanced uses from working
3442(for example, running a Python script as an NT service, or possibly
3443from CGI).
3444
3445[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3446installer; instead, it installs the needed Tcl/Tk files directly in the
3447Python directory. If you already have a Tcl/Tk installation, this
3448wastes some disk space (about 4 Megs) but avoids problems with
3449conflicting Tcl/Tk installations, and makes it much easier for Python
3450to ensure that Tcl/Tk can find all its files.
3451
3452[This was new in 1.6] The Windows installer now installs by default in
3453\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3454
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003455
3456Updates to the changes between 1.5.2 and 1.6
3457--------------------------------------------
3458
3459The 1.6 NEWS file can't be changed after the release is done, so here
3460is some late-breaking news:
3461
3462New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3463and changes to getlocale() and setlocale().
3464
3465The new module is now enabled per default.
3466
3467It is not true that the encodings codecs cannot be used for normal
3468strings: the string.encode() (which is also present on 8-bit strings
3469!) allows using them for 8-bit strings too, e.g. to convert files from
3470cp1252 (Windows) to latin-1 or vice-versa.
3471
3472Japanese codecs are available from Tamito KAJIYAMA:
3473http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3474
3475
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003476======================================================================