blob: 99c354784398a5ad9b8cc6af82557f4fd5a6155d [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Guido van Rossumc7c36502002-06-21 01:29:25 +00009- The __slots__ variable can now mention "private" names, and the
10 right thing will happen (e.g. __slots__ = ["__foo"]).
11
Walter Dörwald3430d702002-06-17 10:43:59 +000012- Unicode objects in sys.path are no longer ignored but treated
13 as directory names.
14
Guido van Rossum9562bcf2002-06-14 21:31:18 +000015- The built-ins slice() and buffer() are now callable types. The
16 types classobj (formerly class), code, function, instance, and
17 instancemethod (formerly instance-method), which have no built-in
18 names but are accessible through the types module, are now also
19 callable. The type dict-proxy is renamed to dictproxy.
20
Neal Norwitz1f68fc72002-06-14 00:50:42 +000021- Fixed string.startswith and string.endswith builtin methods
22 so they accept negative indices. [SF bug 493951]
23
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000024- Fixed a bug with a continue inside a try block and a yield in the
25 finally clause. [SF bug 567538]
26
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000027- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000028 with a third "stride" parameter. For example, "hello world"[::-1]
29 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000030
Guido van Rossum9f7549b2002-06-10 21:39:42 +000031- Cycles going through the __class__ link of a new-style instance are
32 now detected by the garbage collector.
33
Guido van Rossum9923ffe2002-06-04 19:52:53 +000034- Classes using __slots__ are now properly garbage collected.
35 [SF bug 519621]
36
37- Tightened the __slots__ rules: a slot name must be a valid Python
38 identifier.
39
Guido van Rossum2e4e0262002-06-04 05:58:34 +000040- The constructor for the module type now requires a name argument and
41 takes an optional docstring argument. Previously, this constructor
42 ignored its arguments. As a consequence, deriving a class from a
43 module (not from the module type) is now illegal; previously this
44 created an unnamed module, just like invoking the module type did.
45 [SF bug 563060]
46
Neal Norwitzd68f5172002-05-29 15:54:55 +000047- A new warning PendingDeprecationWarning was added to provide
48 direction on features which are in the process of being deprecated.
49 The warning will not be printed by default. To see the pending
50 deprecations, use -Walways::PendingDeprecationWarning::
51 as a command line option or warnings.filterwarnings() in code.
52
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000053- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000054 for 'str' and 'unicode', and can be used instead of
55 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000056 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000057 is an abstract base class and cannot be instantiated directly.
58
Fred Draked0ba6362002-05-02 21:28:26 +000059- Deprecated features of xrange objects have been removed as
60 promised. The start, stop, and step attributes and the tolist()
61 method no longer exist. xrange repetition and slicing have been
62 removed.
63
Guido van Rossum7dab2422002-04-26 19:40:56 +000064- New builtin function enumerate(x), from PEP 279. Example:
65 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
66 The argument can be an arbitrary iterable object.
67
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000068- The assert statement no longer tests __debug__ at runtime. This means
69 that assert statements cannot be disabled by assigning a false value
70 to __debug__.
71
Walter Dörwald068325e2002-04-15 13:36:47 +000072- A method zfill() was added to str and unicode, that fills a numeric
73 string to the left with zeros. For example,
74 "+123".zfill(6) -> "+00123".
75
Guido van Rossum862fe3c2002-04-15 12:36:47 +000076- Complex numbers supported divmod() and the // and % operators, but
77 these make no sense. Since this was documented, they're being
78 deprecated now.
79
Guido van Rossum26dd8302002-04-26 20:11:29 +000080- String and unicode methods lstrip(), rstrip() and strip() now take
81 an optional argument that specifies the characters to strip. For
82 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000083
Guido van Rossumc69343b2002-04-12 19:22:48 +000084- Added a new dict method pop(key). This removes and returns the
85 value corresponding to key. [SF patch #539949]
86
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000087- Changed new-style class instantiation so that when C's __new__
88 method returns something that's not a C instance, its __init__ is
89 not called. [SF bug #537450]
90
Guido van Rossum181e41a2002-04-06 00:23:25 +000091- Fixed super() to work correctly with class methods. [SF bug #535444]
92
Guido van Rossum47834462002-04-04 15:21:33 +000093- A new built-in type, bool, has been added, as well as built-in
94 names for its two values, True and False. Comparisons and sundry
95 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000096 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000097 is backward compatible.
98
Guido van Rossum95b62a62002-03-29 01:07:24 +000099- Fixed two bugs reported as SF #535905: under certain conditions,
100 deallocating a deeply nested structure could cause a segfault in the
101 garbage collector, due to interaction with the "trashcan" code;
102 access to the current frame during destruction of a local variable
103 could access a pointer to freed memory.
104
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000105- The optional object allocator ("pymalloc") has been enabled by
106 default. The recommended practice for memory allocation and
107 deallocation has been streamlined. A header file is included,
108 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
109 and lets them use the same API with Python versions from 1.5.2
110 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000111
Guido van Rossum8c842552002-03-14 23:05:54 +0000112- If you try to pickle an instance of a class that has __slots__ but
113 doesn't define or override __getstate__, a TypeError is now raised.
114 This is done by adding a bozo __getstate__ to the class that always
115 raises TypeError. (Before, this would appear to be pickled, but the
116 state of the slots would be lost.)
117
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000118- PyErr_Display will provide file and line information for all exceptions
119 that have an attribute print_file_and_line, not just SyntaxErrors.
120
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000121- The UTF-8 codec will now encode and decode Unicode surrogates
122 correctly and without raising exceptions for unpaired ones.
123
Neal Norwitz649b7592002-01-01 19:07:13 +0000124- file.xreadlines() now raises a ValueError if the file is closed:
125 Previously, an xreadlines object was returned which would raise
126 a ValueError when the xreadlines.next() method was called.
127
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000128- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000129 An exception will now be raised if more than one argument is used.
130
Tim Petersaf8446f2001-12-21 21:36:50 +0000131Extension modules
132
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000133- The 'new' module is no longer an extension, but a Python module that
134 only exists for backwards compatibility. Its contents are no longer
135 functions but callable type objects.
136
Tim Peters81b92512002-04-29 01:37:32 +0000137- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000138 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000139 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000140
Martin v. Löwis606edc12002-06-13 21:09:11 +0000141- posix.killpg, posix.mknod, and posix.getpgid have been added where
142 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000143
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000144- The locale module now exposes the C library's gettext interface.
145
Tim Petersfbf74f22002-03-14 19:06:01 +0000146- A security hole ("double free") was found in zlib-1.1.3, a popular
147 third party compression library used by some Python modules. The
148 hole was quickly plugged in zlib-1.1.4, and the Windows build of
149 Python now ships with zlib-1.1.4.
150
Martin v. Löwis688357e2002-04-08 21:28:20 +0000151- pwd, grp, and resource return enhanced tuples now, with symbolic
152 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000153
Martin v. Löwis99866332002-03-01 10:27:01 +0000154- array.array is now a type object. A new format character
155 'u' indicates Py_UNICODE arrays. For those, .tounicode and
156 .fromunicode methods are available. Arrays now support __iadd__
157 and __imul__.
158
Neal Norwitze790eae2002-01-01 21:14:12 +0000159- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000160 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
161 is called.
162
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000163- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
164 been added where available.
165
Tim Petersaf8446f2001-12-21 21:36:50 +0000166Library
167
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000168- Some fixes in the copy module: when an object is copied through its
169 __reduce__ method, there was no check for a __setstate__ method on
170 the result [SF patch 565085]; deepcopy should treat instances of
171 custom metaclasses the same way it treats instances of type 'type'
172 [SF patch 560794].
173
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000174- Sockets now support timeout mode. After s.settimeout(T), where T is
175 a float expressing seconds, subsequent operations raise an exception
176 if they cannot be completed within T seconds. To disable timeout
177 mode, use s.settimeout(None).
178
179- getopt.gnu_getopt was added. This supports GNU-style option
180 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000181
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000182- Stop using strings for exceptions. String objects used for
183 exceptions are now classes deriving from Exception. The objects
184 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
185 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000186
Walter Dörwald474458d2002-06-04 15:16:29 +0000187- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
188 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
189 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
190 big endian systems were added to the codecs module. The old names
191 BOM32_* and BOM64_* were off by a factor of 2.
192
Guido van Rossumf9257822002-06-18 20:43:18 +0000193- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000194
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000195- ftplib.retrlines() now tests for callback is None rather than testing
196 for False. Was causing an error when given a callback object which
197 was callable but also returned len() as zero. The change may
198 create new breakage if the caller relied on the undocumented behavior
199 and called with callback set to [] or some other False value not
200 identical to None.
201
Tim Peters46c04e12002-05-05 20:40:00 +0000202- random.gauss() uses a piece of hidden state used by nothing else,
203 and the .seed() and .whseed() methods failed to reset it. In other
204 words, setting the seed didn't completely determine the sequence of
205 results produced by random.gauss(). It does now. Programs repeatedly
206 mixing calls to a seed method with calls to gauss() may see different
207 results now.
208
Fred Drake7f781c92002-05-01 20:33:53 +0000209- The pickle.Pickler class grew a clear_memo() method to mimic that
210 provided by cPickle.Pickler.
211
Tim Peters81b92512002-04-29 01:37:32 +0000212- difflib's SequenceMatcher class now does a dynamic analysis of
213 which elements are so frequent as to constitute noise. For
214 comparing files as sequences of lines, this generally works better
215 than the IS_LINE_JUNK function, and function ndiff's linejunk
216 argument defaults to None now as a result. A happy benefit is
217 that SequenceMatcher may run much faster now when applied
218 to large files with many duplicate lines (for example, C program
219 text with lots of repeated "}" and "return NULL;" lines).
220
Guido van Rossum256705b2002-04-23 13:29:43 +0000221- New Text.dump() method in Tkinter module.
222
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000223- New distutils commands for building packagers were added to
224 support pkgtool on Solaris and swinstall on HP-UX.
225
226- distutils now has a new abstract binary packager base class
227 command/bdist_packager, which simplifies writing packagers.
228 This will hopefully provide the missing bits to encourage
229 people to submit more packagers, e.g. for Debian, FreeBSD
230 and other systems.
231
Guido van Rossumf9257822002-06-18 20:43:18 +0000232- The UTF-16, -LE and -BE stream readers now raise a
233 NotImplementedError for all calls to .readline(). Previously, they
234 used to just produce garbage or fail with an encoding error --
235 UTF-16 is a 2-byte encoding and the C lib's line reading APIs don't
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000236 work well with these.
237
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000238- compileall now supports quiet operation.
239
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000240- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000241 connections.
242
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000243- socket module: the SSL support was broken out of the main
244 _socket module C helper and placed into a new _ssl helper
245 which now gets imported by socket.py if available and working.
246
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000247- encodings package: added aliases for all supported IANA character
248 sets
249
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000250- ftplib: to safeguard the user's privacy, anonymous login will use
251 "anonymous@" as default password, rather than the real user and host
252 name.
253
Fred Drake36736122002-01-10 13:50:31 +0000254- webbrowser: tightened up the command passed to os.system() so that
255 arbitrary shell code can't be executed because a bogus URL was
256 passed in.
257
Tim Peters11bd9942002-02-01 00:52:29 +0000258- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000259 gettext.find an optional all argument. Translations will now fallback
260 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000261
Martin v. Löwis9668b932002-01-12 11:27:42 +0000262- distutils bdist commands now offer a --skip-build option.
263
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000264- warnings.warn now accepts a Warning instance as first argument.
265
Fred Drakefed7e852002-04-04 19:36:15 +0000266- The xml.sax.expatreader.ExpatParser class will no longer create
267 circular references by using itself as the locator that gets passed
268 to the content handler implementation. [SF bug #535474]
269
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000270- The email.Parser.Parser class now properly parses strings regardless
271 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
272 or CRLF). Also, the Header class's constructor default arguments
273 has changed slightly so that an explicit maxlinelen value is always
274 honored.
275
Tim Petersaf8446f2001-12-21 21:36:50 +0000276Tools/Demos
277
Marc-André Lemburg46260092002-04-04 16:17:11 +0000278- freeze.py now produces binaries which can import shared modules,
279 unlike before when this failed due to missing symbol exports in
280 the generated binary.
281
Tim Petersaf8446f2001-12-21 21:36:50 +0000282Build
283
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000284- The configure option --without-doc-strings can be used to remove the
285 doc strings from the builtin functions and modules; this reduces the
286 size of the executable.
287
Tim Peters639295f2002-04-21 07:30:30 +0000288- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
289 say how or when to configure it, or how to turn it off.
290
Martin v. Löwis1142de32002-03-29 16:28:31 +0000291- On Unix, a shared libpython2.3.so can be created with --enable-shared.
292
Tim Peters8deda702002-03-30 10:06:07 +0000293- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
294 preprocessor symbols were eliminated. The internal decisions they
295 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000296
Fred Drake7d28b732002-05-02 21:17:00 +0000297- The tools used to build the documentation now work under Cygwin as
298 well as Unix.
299
Skip Montanaro57454e52002-06-14 20:30:31 +0000300- The bsddb and dbm module builds have been changed to try and avoid version
301 skew problems and disable linkage with Berkeley DB 1.85 unless the
302 installer knows what s/he's doing. See the section on building these
303 modules in the README file for details.
304
Tim Petersaf8446f2001-12-21 21:36:50 +0000305C API
306
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000307- Added new macro PySequence_ITEM(o, i) that directly calls
308 sq_item without rechecking that o is a sequence and without
309 adjusting for negative indices.
310
Fred Draked0ba6362002-05-02 21:28:26 +0000311- PyRange_New() now raises ValueError if the fourth argument is not 1.
312 This is part of the removal of deprecated features of the xrange
313 object.
314
Guido van Rossum517c7d42002-04-26 02:49:14 +0000315- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
316 coercion if both arguments have the same type but this type has the
317 CHECKTYPES flag set. This is to better support proxies.
318
Neil Schemenauer9344b142002-04-12 23:00:08 +0000319- The type of tp_free has been changed from "void (*)(PyObject *)" to
320 "void (*)(void *)".
321
322- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
323
Guido van Rossum0986d822002-04-08 01:38:42 +0000324- A type can now inherit its metatype from its base type. Previously,
325 when PyType_Ready() was called, if ob_type was found to be NULL, it
326 was always set to &PyType_Type; now it is set to base->ob_type,
327 where base is tp_base, defaulting to &PyObject_Type.
328
329- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
330
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000331- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000332
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000333- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000334 without going through the buffer API.
335
Martin v. Löwis7198a522002-01-01 19:59:11 +0000336- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
337
Tim Peters10a3bb52001-12-25 19:07:38 +0000338- An old #define of ANY as void has been removed from pyport.h. This
339 hasn't been used since Python's pre-ANSI days, and the #define has
340 been marked as obsolete since then. SF bug 495548 says it created
341 conflicts with other packages, so keeping it around wasn't harmless.
342
Tim Petersaf8446f2001-12-21 21:36:50 +0000343- Because Python's magic number scheme broke on January 1st, we decided
344 to stop Python development. Thanks for all the fish!
345
Tim Petersfb05db22002-03-11 00:24:00 +0000346- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000347 scheme to a new one. See Python/import.c for details.
348
Tim Petersaf8446f2001-12-21 21:36:50 +0000349New platforms
350
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000351- AtheOS is now supported.
352
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000353- GNU/Hurd is now supported.
354
Tim Petersaf8446f2001-12-21 21:36:50 +0000355Tests
356
357Windows
358
Tim Peters08e72952002-04-16 20:48:01 +0000359- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
360 of that has been fixed in the installer (disabled Wise's "delete in-
361 use files" uninstall option).
362
Guido van Rossum181e41a2002-04-06 00:23:25 +0000363- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
364
Tim Peters33187922002-04-04 20:02:04 +0000365- The installer now installs Start menu shortcuts under (the local
366 equivalent of) "All Users" when doing an Admin install.
367
Tim Petersfb05db22002-03-11 00:24:00 +0000368- file.truncate([newsize]) now works on Windows for all newsize values.
369 It used to fail if newsize didn't fit in 32 bits, reflecting a
370 limitation of MS _chsize (which is no longer used).
371
Tim Petersab034fa2002-02-01 11:27:43 +0000372- os.waitpid() is now implemented for Windows, and can be used to block
373 until a specified process exits. This is similar to, but not exactly
374 the same as, os.waitpid() on POSIX systems. If you're waiting for
375 a specific process whose pid was obtained from one of the spawn()
376 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000377 See the docs for details. The docs were changed to clarify that
378 spawn functions return, and waitpid requires, a process handle on
379 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000380
Tim Peters11bd9942002-02-01 00:52:29 +0000381- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000382 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000383 to a nasty problem: before 2.3, if you got a temp file on Windows, it
384 got wrapped in an object whose close() method first closed the
385 underlying file, then deleted the file. This usually worked fine.
386 However, the spawn family of functions on Windows create (at a low C
387 level) the same set of open files in the spawned process Q as were
388 open in the spawning process P. If a temp file f was among them, then
389 doing f.close() in P first closed P's C-level file handle on f, but Q's
390 C-level file handle on f remained open, so the attempt in P to delete f
391 blew up with a "Permission denied" error (Windows doesn't allow
392 deleting open files). This was surprising, subtle, and difficult to
393 work around.
394
395- The os module now exports all the symbolic constants usable with the
396 low-level os.open() on Windows: the new constants in 2.3 are
397 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
398 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
399 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
400 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
401 (so specify both if you want both; note that neither is useful unless
402 specified with O_CREAT too).
403
Tim Petersaf8446f2001-12-21 21:36:50 +0000404Mac
405
406
Tim Peters909c0912001-12-14 23:16:18 +0000407What's New in Python 2.2 final?
408Release date: 21-Dec-2001
409===============================
410
411Type/class unification and new-style classes
412
Barry Warsaw52acb492001-12-21 20:04:22 +0000413- pickle.py, cPickle: allow pickling instances of new-style classes
414 with a custom metaclass.
415
Tim Peters909c0912001-12-14 23:16:18 +0000416Core and builtins
417
Barry Warsaw52acb492001-12-21 20:04:22 +0000418- weakref proxy object: when comparing, unwrap both arguments if both
419 are proxies.
420
Tim Peters909c0912001-12-14 23:16:18 +0000421Extension modules
422
Barry Warsaw52acb492001-12-21 20:04:22 +0000423- binascii.b2a_base64(): fix a potential buffer overrun when encoding
424 very short strings.
425
426- cPickle: the obscure "fast" mode was suspected of causing stack
427 overflows on the Mac. Hopefully fixed this by setting the recursion
428 limit much smaller. If the limit is too low (it only affects
429 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
430 when compiling cPickle.c (or in pyconfig.h).
431
Tim Peters909c0912001-12-14 23:16:18 +0000432Library
433
Barry Warsaw52acb492001-12-21 20:04:22 +0000434- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
435 close or delete time).
436
437- rfc822.py: fixed a bug where the address '<>' was converted to None
438 instead of an empty string (also fixes the email.Utils module).
439
440- xmlrpclib.py: version 1.0.0; uses precision for doubles.
441
442- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000443 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000444
Tim Peters909c0912001-12-14 23:16:18 +0000445Tools/Demos
446
447Build
448
449C API
450
451New platforms
452
453Tests
454
455Windows
456
Barry Warsaw52acb492001-12-21 20:04:22 +0000457- distutils package: fixed broken Windows installers (bdist_wininst).
458
459- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
460 instances are deleted at process exit time.
461
462- socket.py: prevent mysterious warnings when socket instances are
463 deleted at process exit time.
464
465- posixmodule.c: fix a Windows crash with stat() of a filename ending
466 in backslash.
467
Tim Peters909c0912001-12-14 23:16:18 +0000468Mac
469
Barry Warsaw52acb492001-12-21 20:04:22 +0000470- The Carbon toolbox modules have been upgraded to Universal Headers
471 3.4, and experimental CoreGraphics and CarbonEvents modules have
472 been added. All only for framework-enabled MacOSX.
473
Tim Peters909c0912001-12-14 23:16:18 +0000474
Tim Peters6272dfd2001-12-13 19:34:00 +0000475What's New in Python 2.2c1?
476Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000477===========================
478
479Type/class unification and new-style classes
480
Barry Warsaw06557452001-12-14 20:47:12 +0000481- Guido's tutorial introduction to the new type/class features has
482 been extensively updated. See
483
484 http://www.python.org/2.2/descrintro.html
485
486 That remains the primary documentation in this area.
487
Guido van Rossum33bab012001-12-05 22:45:48 +0000488- Fixed a leak: instance variables declared with __slots__ were never
489 deleted!
490
Guido van Rossum4b800852001-12-03 00:54:52 +0000491- The "delete attribute" method of descriptor objects is called
492 __delete__, not __del__. In previous releases, it was mistakenly
493 called __del__, which created an unfortunate overloading condition
494 with finalizers. (The "get attribute" and "set attribute" methods
495 are still called __get__ and __set__, respectively.)
496
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000497- Some subtle issues with the super built-in were fixed:
498
499 (a) When super itself is subclassed, its __get__ method would still
500 return an instance of the base class (i.e., of super).
501
502 (b) super(C, C()).__class__ would return C rather than super. This
503 is confusing. To fix this, I decided to change the semantics of
504 super so that it only applies to code attributes, not to data
505 attributes. After all, overriding data attributes is not
506 supported anyway.
507
508 (c) The __get__ method didn't check whether the argument was an
509 instance of the type used in creation of the super instance.
510
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000511- Previously, hash() of an instance of a subclass of a mutable type
512 (list or dictionary) would return some value, rather than raising
513 TypeError. This has been fixed. Also, directly calling
514 dict.__hash__ and list.__hash__ now raises the same TypeError
515 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000516
Guido van Rossumd331cb52001-12-05 19:46:42 +0000517- New-style objects now support deleting their __dict__. This is for
518 all intents and purposes equivalent to assigning a brand new empty
519 dictionary, but saves space if the object is not used further.
520
Tim Petersb3c9af12001-11-17 00:21:57 +0000521Core and builtins
522
Tim Peters3caca232001-12-06 06:23:26 +0000523- -Qnew now works as documented in PEP 238: when -Qnew is passed on
524 the command line, all occurrences of "/" use true division instead
525 of classic division. See the PEP for details. Note that "all"
526 means all instances in library and 3rd-party modules, as well as in
527 your own code. As the PEP says, -Qnew is intended for use only in
528 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000529 Note that test_coercion.py in the standard Python test suite fails
530 under -Qnew; this is expected, and won't be repaired until true
531 division becomes the default (in the meantime, test_coercion is
532 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000533
Fred Drake6c01e252001-12-14 17:08:12 +0000534- complex() now only allows the first argument to be a string
535 argument, and raises TypeError if either the second arg is a string
536 or if the second arg is specified when the first is a string.
537
Tim Petersb3c9af12001-11-17 00:21:57 +0000538Extension modules
539
Martin v. Löwis560da622001-11-24 09:24:51 +0000540- gc.get_referents was renamed to gc.get_referrers.
541
Tim Petersb3c9af12001-11-17 00:21:57 +0000542Library
543
Tim Peters25059d32001-12-07 20:35:43 +0000544- Functions in the os.spawn() family now release the global interpreter
545 lock around calling the platform spawn. They should always have done
546 this, but did not before 2.2c1. Multithreaded programs calling
547 an os.spawn function with P_WAIT will no longer block all Python threads
548 until the spawned program completes. It's possible that some programs
549 relies on blocking, although more likely by accident than by design.
550
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000551- webbrowser defaults to netscape.exe on OS/2 now.
552
Martin v. Löwis652e1912001-11-25 14:50:56 +0000553- Tix.ResizeHandle exposes detach_widget, hide, and show.
554
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000555- The charset alias windows_1252 has been added.
556
Barry Warsaw06557452001-12-14 20:47:12 +0000557- types.StringTypes is a tuple containing the defined string types;
558 usually this will be (str, unicode), but if Python was compiled
559 without Unicode support it will be just (str,).
560
561- The pulldom and minidom modules were synchronized to PyXML.
562
Tim Petersb3c9af12001-11-17 00:21:57 +0000563Tools/Demos
564
Barry Warsaw06557452001-12-14 20:47:12 +0000565- A new script called Tools/scripts/google.py was added, which fires
566 off a search on Google.
567
Tim Petersb3c9af12001-11-17 00:21:57 +0000568Build
569
Barry Warsaw06557452001-12-14 20:47:12 +0000570- Note that release builds of Python should arrange to define the
571 preprocessor symbol NDEBUG on the command line (or equivalent).
572 In the 2.2 pre-release series we tried to define this by magic in
573 Python.h instead, but it proved to cause problems for extension
574 authors. The Unix, Windows and Mac builds now all define NDEBUG in
575 release builds via cmdline (or equivalent) instead. Ports to
576 other platforms should do likewise.
577
Jack Jansen1999ef42001-12-06 21:47:20 +0000578- It is no longer necessary to use --with-suffix when building on a
579 case-insensitive file system (such as Mac OS X HFS+). In the build
580 directory an extension is used, but not in the installed python.
581
Tim Petersb3c9af12001-11-17 00:21:57 +0000582C API
583
Tim Petersf582b822001-12-11 18:51:08 +0000584- New function PyDict_MergeFromSeq2() exposes the builtin dict
585 constructor's logic for updating a dictionary from an iterable object
586 producing key-value pairs.
587
Tim Peterscffed4b2001-11-29 03:26:37 +0000588- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000589 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000590 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
591 dump core in some bad cases. This has been repaired. As a result,
592 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
593 previously went unchallenged.
594
Tim Petersb3c9af12001-11-17 00:21:57 +0000595New platforms
596
597Tests
598
599Windows
600
601Mac
602
Jack Jansenffa260f2001-12-06 21:14:00 +0000603- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
604 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000605
Barry Warsaw06557452001-12-14 20:47:12 +0000606- Changed logic for finding python home in Mac OS X framework Pythons.
607 Now sys.executable points to the executable again, in stead of to
608 the shared library. The latter is used only for locating the python
609 home.
610
611
Tim Peters84362bc2001-10-19 17:55:30 +0000612What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000613Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000614===========================
615
616Type/class unification and new-style classes
617
Guido van Rossum3d27df02001-11-15 20:27:54 +0000618- Multiple inheritance mixing new-style and classic classes in the
619 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000620
621 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000622 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000623
624 The MRO (method resolution order) for each base class is respected
625 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000626 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000627 This needs to be documented.
628
Tim Petersa427a2b2001-10-29 22:25:45 +0000629- The new builtin dictionary() constructor, and dictionary type, have
630 been renamed to dict. This reflects a decade of common usage.
631
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000632- dict() now accepts an iterable object producing 2-sequences. For
633 example, dict(d.items()) == d for any dictionary d. The argument,
634 and the elements of the argument, can be any iterable objects.
635
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000636- New-style classes can now have a __del__ method, which is called
637 when the instance is deleted (just like for classic classes).
638
Guido van Rossum12d955c2001-10-26 14:56:06 +0000639- Assignment to object.__dict__ is now possible, for objects that are
640 instances of new-style classes that have a __dict__ (unless the base
641 class forbids it).
642
Guido van Rossumc8e56452001-10-22 00:43:43 +0000643- Methods of built-in types now properly check for keyword arguments
644 (formerly these were silently ignored). The only built-in methods
645 that take keyword arguments are __call__, __init__ and __new__.
646
Guido van Rossum86443212001-10-27 22:28:54 +0000647- The socket function has been converted to a type; see below.
648
Tim Peters84362bc2001-10-19 17:55:30 +0000649Core and builtins
650
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000651- Assignment to __debug__ raises SyntaxError at compile-time. This
652 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000653 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000654
Guido van Rossum12d955c2001-10-26 14:56:06 +0000655- Clarified the error messages for unsupported operands to an operator
656 (like 1 + '').
657
Tim Peters84362bc2001-10-19 17:55:30 +0000658Extension modules
659
Tim Peters5ebfd362001-11-13 23:11:19 +0000660- mmap has a new keyword argument, "access", allowing a uniform way for
661 both Windows and Unix users to create read-only, write-through and
662 copy-on-write memory mappings. This was previously possible only on
663 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000664 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000665 platforms. Thanks to Jay T Miller for repairing this!
666
Tim Peters169ded02001-11-03 19:57:21 +0000667- By default, the gc.garbage list now contains only those instances in
668 unreachable cycles that have __del__ methods; in 2.1 it contained all
669 instances in unreachable cycles. "Instances" here has been generalized
670 to include instances of both new-style and old-style classes.
671
Guido van Rossum12d955c2001-10-26 14:56:06 +0000672- The socket module defines a new method for socket objects,
673 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000674 send() until all data has been sent. Also, the socket function has
675 been converted to a subclassable type, like list and tuple (etc.)
676 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000677
678- Various bugfixes to the curses module. There is now a test suite
679 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000680
Guido van Rossum692adf12001-10-30 03:03:03 +0000681- binascii.b2a_base64 no longer places an arbitrary restriction of 57
682 bytes on its input.
683
Tim Peters84362bc2001-10-19 17:55:30 +0000684Library
685
Tim Peters5ebfd362001-11-13 23:11:19 +0000686- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000687 convenience function.
688
Tim Peters75335872001-11-03 19:35:43 +0000689- Symbolic group names in regular expressions must be unique. For
690 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
691 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000692 Python 2.2 detects this error at regexp compilation time;
693 previously, the error went undetected, and results were
694 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
695 pattern.subn() methods have been rewritten in C. Also, an
696 experimental function/method finditer() has been added, which works
697 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000698
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000699- Tix exposes more commands through the classes DirSelectBox,
700 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
701 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
702 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
703
Tim Peters98791af2001-10-23 01:59:54 +0000704- Traceback objects are now scanned by cyclic garbage collection, so
705 cycles created by casual use of sys.exc_info() no longer cause
706 permanent memory leaks (provided garbage collection is enabled).
707
Guido van Rossum49192142001-10-24 20:51:44 +0000708- os.extsep -- a new variable needed by the RISCOS support. It is the
709 separator used by extensions, and is '.' on all platforms except
710 RISCOS, where it is '/'. There is no need to use this variable
711 unless you have a masochistic desire to port your code to RISCOS.
712
Barry Warsaw012852b2001-11-16 16:17:27 +0000713- mimetypes.py has optional support for non-standard, but commonly
714 found types. guess_type() and guess_extension() now accept an
715 optional `strict' flag, defaulting to true, which controls whether
716 recognize non-standard types or not. A few non-standard types we
717 know about have been added. Also, when run as a script, there are
718 new -l and -e options.
719
720- statcache is now deprecated.
721
722- email.Utils.formatdate() now produces the preferred RFC 2822 style
723 dates with numeric timezones (it used to produce obsolete dates
724 hard coded to "GMT" timezone). An optional `localtime' flag is
725 added to produce dates in the local timezone, with daylight savings
726 time properly taken into account.
727
728- In pickle and cPickle, instead of masking errors in load() by
729 transforming them into SystemError, we let the original exception
730 propagate out. Also, implement support for __safe_for_unpickling__
731 in pickle, as it already was supported in cPickle.
732
Tim Peters84362bc2001-10-19 17:55:30 +0000733Tools/Demos
734
735Build
736
Barry Warsaw012852b2001-11-16 16:17:27 +0000737- The dbm module is built using libdb1 if available. The bsddb module
738 is built with libdb3 if available.
739
740- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
741
Tim Peters84362bc2001-10-19 17:55:30 +0000742C API
743
Tim Peters1fc240e2001-10-26 05:06:50 +0000744- New function PySequence_Fast_GET_SIZE() returns the size of a non-
745 NULL result from PySequence_Fast(), more quickly than calling
746 PySequence_Size().
747
Barry Warsaw012852b2001-11-16 16:17:27 +0000748- New argument unpacking function PyArg_UnpackTuple() added.
749
750- New functions PyObject_CallFunctionObjArgs() and
751 PyObject_CallMethodObjArgs() have been added to make it more
752 convenient and efficient to call functions and methods from C.
753
754- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
755 possible that this will propagate errors it didn't before.
756
757- New function PyObject_CheckReadBuffer(), which returns true if its
758 argument supports the single-segment readable buffer interface.
759
Tim Peters84362bc2001-10-19 17:55:30 +0000760New platforms
761
Guido van Rossum86443212001-10-27 22:28:54 +0000762- We've finally confirmed that this release builds on HP-UX 11.00,
763 *with* threads, and passes the test suite.
764
Tim Peters7a33d8b2001-11-05 02:51:07 +0000765- Thanks to a series of patches from Michael Muller, Python may build
766 again under OS/2 Visual Age C++.
767
Guido van Rossum49192142001-10-24 20:51:44 +0000768- Updated RISCOS port by Dietmar Schwertberger.
769
Tim Peters84362bc2001-10-19 17:55:30 +0000770Tests
771
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000772- Added a test script for the curses module. It isn't run automatically;
773 regrtest.py must be run with '-u curses' to enable it.
774
Tim Peters84362bc2001-10-19 17:55:30 +0000775Windows
776
Barry Warsaw012852b2001-11-16 16:17:27 +0000777Mac
778
779- PythonScript has been moved to unsupported and is slated to be
780 removed completely in the next release.
781
782- It should now be possible to build applets that work on both OS9 and
783 OSX.
784
785- The core is now linked with CoreServices not Carbon; as a side
786 result, default 8bit encoding on OSX is now ASCII.
787
788- Python should now build on OSX 10.1.1
789
Tim Peters84362bc2001-10-19 17:55:30 +0000790
Tim Petersabf925f2001-09-28 21:53:42 +0000791What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000792Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000793===========================
794
795Type/class unification and new-style classes
796
Guido van Rossum687ae002001-10-15 22:03:32 +0000797- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000798 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000799 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000800 remains: the __dict__ of a new-style class is a read-only proxy; you
801 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000802 __defined__ attribute of new-style types no longer exists, for lack
803 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000804 future a __cache__ may be resurrected with a similar function, if I
805 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000806
Tim Peters1c9ca872001-10-04 06:43:12 +0000807- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
808 always returned None, even when there was a class docstring).
809
810- doctest now finds and runs docstrings attached to new-style classes,
811 class methods, static methods, and properties.
812
Guido van Rossum9074ef62001-10-16 21:34:49 +0000813Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000814
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000815- A very subtle syntactical pitfall in list comprehensions was fixed.
816 For example: [a+b for a in 'abc', for b in 'def']. The comma in
817 this example is a mistake. Previously, this would silently let 'a'
818 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
819 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
820 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
821 Note that [a for a in <singleton>] is a convoluted way to say
822 [<singleton>] anyway, so it's not like any expressiveness is lost.
823
Guido van Rossum9074ef62001-10-16 21:34:49 +0000824- getattr(obj, name, default) now only catches AttributeError, as
825 documented, rather than returning the default value for all
826 exceptions (which could mask bugs in a __getattr__ hook, for
827 example).
828
Fred Drakecb7a6b52001-10-22 18:41:51 +0000829- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000830 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000831 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000832 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000833
Guido van Rossum1c486092001-10-19 02:05:35 +0000834- unicode(obj) now behaves more like str(obj), accepting arbitrary
835 objects, and calling a __unicode__ method if it exists.
836 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000837 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000838
Barry Warsawf6fb1712001-10-19 05:35:40 +0000839- isinstance() now allows any object as the first argument and a
840 class, a type or something with a __bases__ tuple attribute for the
841 second argument. The second argument may also be a tuple of a
842 class, type, or something with __bases__, in which case isinstance()
843 will return true if the first argument is an instance of any of the
844 things contained in the second argument tuple. E.g.
845
846 isinstance(x, (A, B))
847
848 returns true if x is an instance of A or B.
849
Guido van Rossum9074ef62001-10-16 21:34:49 +0000850Extension modules
851
852- thread.start_new_thread() now returns the thread ID (previously None).
853
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000854- binascii has now two quopri support functions, a2b_qp and b2a_qp.
855
Guido van Rossumc524d952001-10-19 01:31:59 +0000856- readline now supports setting the startup_hook and the
857 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000858
Guido van Rossumc524d952001-10-19 01:31:59 +0000859- os and posix supports chroot(), setgroups() and unsetenv() where
860 available. The stat(), fstat(), statvfs() and fstatvfs() functions
861 now return "pseudo-sequences" -- the various fields can now be
862 accessed as attributes (e.g. os.stat("/").st_mtime) but for
863 backwards compatibility they also behave as a fixed-length sequence.
864 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000865 attributes.
866
867- time: localtime(), gmtime() and strptime() now return a
868 pseudo-sequence similar to the os.stat() return value, with
869 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000870
Guido van Rossum9074ef62001-10-16 21:34:49 +0000871- Decompression objects in the zlib module now accept an optional
872 second parameter to decompress() that specifies the maximum amount
873 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000874
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000875- optional SSL support in the socket module now exports OpenSSL
876 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
877 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000878 automatically seed its PRNG. Also, the keyfile and certfile
879 arguments to socket.ssl() are now optional.
880
881- posixmodule (and by extension, the os module on POSIX platforms) now
882 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000883
Guido van Rossum9074ef62001-10-16 21:34:49 +0000884Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000885
Tim Peters7402f792001-10-02 03:53:41 +0000886- doctest now excludes functions and classes not defined by the module
887 being tested, thanks to Tim Hochberg.
888
Fred Drakecb7a6b52001-10-22 18:41:51 +0000889- HotShot, a new profiler implemented using a C-based callback, has
890 been added. This substantially reduces the overhead of profiling,
891 but it is still quite preliminary. Support modules and
892 documentation will be added in upcoming releases (before 2.2 final).
893
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000894- profile now produces correct output in situations where an exception
895 raised in Python is cleared by C code (e.g. hasattr()). This used
896 to cause wrong output, including spurious claims of recursive
897 functions and attribution of time spent to the wrong function.
898
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000899 The code and documentation for the derived OldProfile and HotProfile
900 profiling classes was removed. The code hasn't worked for years (if
901 you tried to use them, they raised exceptions). OldProfile
902 intended to reproduce the behavior of the profiler Python used more
903 than 7 years ago, and isn't interesting anymore. HotProfile intended
904 to provide a faster profiler (but producing less information), and
905 that's a worthy goal we intend to meet via a different approach (but
906 without losing information).
907
Tim Peterscce092d2001-10-09 05:31:56 +0000908- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000909 a much better system-specific calibration constant. The constant can
910 now be specified in an instance constructor, or as a Profile class or
911 instance variable, instead of by editing profile.py's source code.
912 Calibration must still be done manually (see the docs for the profile
913 module).
914
915 Note that Profile.calibrate() must be overriden by subclasses.
916 Improving the accuracy required exploiting detailed knowledge of
917 profiler internals; the earlier method abstracted away the details
918 and measured a simplified model instead, but consequently computed
919 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000920
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000921- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000922 which indicates whether output is intended for the header 'Q'
923 encoding.
924
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000925- The SocketServer.ThreadingMixIn class now closes the request after
926 finish_request() returns. (Not when it errors out though.)
927
Barry Warsawf6fb1712001-10-19 05:35:40 +0000928- The nntplib module's NNTP.body() method has grown a `file' argument
929 to allow saving the message body to a file.
930
931- The email package has added a class email.Parser.HeaderParser which
932 only parses headers and does not recurse into the message's body.
933 Also, the module/class MIMEAudio has been added for representing
934 audio data (contributed by Anthony Baxter).
935
936- ftplib should be able to handle files > 2GB.
937
938- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
939 ON, and OFF.
940
Fred Drakecb7a6b52001-10-22 18:41:51 +0000941- xml.dom.minidom NodeList objects now support the length attribute
942 and item() method as required by the DOM specifications.
943
Guido van Rossumed554f62001-10-02 23:15:37 +0000944Tools/Demos
945
946- Demo/dns was removed. It no longer serves any purpose; a package
947 derived from it is now maintained by Anthony Baxter, see
948 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000949
Barry Warsawf6fb1712001-10-19 05:35:40 +0000950- The freeze tool has been made more robust, and two new options have
951 been added: -X and -E.
952
Tim Petersabf925f2001-09-28 21:53:42 +0000953Build
954
Barry Warsawf6fb1712001-10-19 05:35:40 +0000955- configure will use CXX in LINKCC if CXX is used to build main() and
956 the system requires to link a C++ main using the C++ compiler.
957
Tim Petersabf925f2001-09-28 21:53:42 +0000958C API
959
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000960- The documentation for the tp_compare slot is updated to require that
961 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
962 not correct. This is not yet enforced but will be enforced in
963 Python 2.3; even later, we may use -2 to indicate errors and +2 for
964 "NotImplemented". Right now, -1 should be used for an error return.
965
Tim Petersd38b1c72001-09-30 05:09:37 +0000966- PyLong_AsLongLong() now accepts int (as well as long) arguments.
967 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
968 as long) arguments.
969
Guido van Rossum3c288632001-10-16 21:13:49 +0000970- PyThread_start_new_thread() now returns a long int giving the thread
971 ID, if one can be calculated; it returns -1 for error, 0 if no
972 thread ID is calculated (this is an incompatible change, but only
973 the thread module used this API). This code has only really been
974 tested on Linux and Windows; other platforms please beware (and
975 report any bugs or strange behavior).
976
Guido van Rossum1c486092001-10-19 02:05:35 +0000977- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
978 input.
979
Tim Petersabf925f2001-09-28 21:53:42 +0000980New platforms
981
982Tests
983
984Windows
985
Tim Peters04cf1d32001-10-09 22:39:40 +0000986- Installer: If you install IDLE, and don't disable file-extension
987 registration, a new "Edit with IDLE" context (right-click) menu entry
988 is created for .py and .pyw files.
989
Tim Peters1ce3cf72001-10-01 17:58:40 +0000990- The signal module now supports SIGBREAK on Windows, thanks to Steven
991 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
992 action remains to call Win32 ExitProcess(). This can be changed via
993 signal.signal(). For example:
994
995 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
996 # (SIGINT) behavior.
997 import signal
998 signal.signal(signal.SIGBREAK,
999 signal.default_int_handler)
1000
1001 try:
1002 while 1:
1003 pass
1004 except KeyboardInterrupt:
1005 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1006 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1007 # program without the possibility for any Python-level cleanup).
1008 print "Clean exit"
1009
Tim Petersabf925f2001-09-28 21:53:42 +00001010
Tim Petersb07352e2001-09-08 01:25:47 +00001011What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001012Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001013===========================
1014
Guido van Rossum808eea72001-09-25 04:15:41 +00001015Type/class unification and new-style classes
1016
1017- pydoc and inspect are now aware of new-style classes;
1018 e.g. help(list) at the interactive prompt now shows proper
1019 documentation for all operations on list objects.
1020
1021- Applications using Jim Fulton's ExtensionClass module can now safely
1022 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1023 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1024 examples also work again. It is hoped that Gtk and Boost also work
1025 with 2.2a4 and beyond. (If you can confirm this, please write
1026 webmaster@python.org; if there are still problems, please open a bug
1027 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001028
Tim Peters66c1a522001-09-24 21:17:50 +00001029- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001030 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001031 in the constructed property object. fget, fset and fdel weren't
1032 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1033 associate a docstring with a property.
1034
Guido van Rossum808eea72001-09-25 04:15:41 +00001035- Comparison overloading is now more completely implemented. For
1036 example, a str subclass instance can properly be compared to a str
1037 instance, and it can properly overload comparison. Ditto for most
1038 other built-in object types.
1039
1040- The repr() of new-style classes has changed; instead of <type
1041 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1042 *except* for built-in types, which are still rendered as <type
1043 'Foo'> (to avoid upsetting existing code that might parse or
1044 otherwise rely on repr() of certain type objects).
1045
1046- The repr() of new-style objects is now always <Foo object at XXX>;
1047 previously, it was sometimes <Foo instance at XXX>.
1048
1049- For new-style classes, what was previously called __getattr__ is now
1050 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001051 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001052 one in classic classes is defined which is called only if regular
1053 attribute access raises AttributeError; to catch *all* attribute
1054 access, you can use __getattribute__ (for new-style classes). If
1055 both are defined, __getattribute__ is called first, and if it raises
1056 AttributeError, __getattr__ is called.
1057
1058- The __class__ attribute of new-style objects can be assigned to.
1059 The new class must have the same C-level object layout as the old
1060 class.
1061
1062- The builtin file type can be subclassed now. In the usual pattern,
1063 "file" is the name of the builtin type, and file() is a new builtin
1064 constructor, with the same signature as the builtin open() function.
1065 file() is now the preferred way to open a file.
1066
1067- Previously, __new__ would only see sequential arguments passed to
1068 the type in a constructor call; __init__ would see both sequential
1069 and keyword arguments. This made no sense whatsoever any more, so
1070 now both __new__ and __init__ see all arguments.
1071
1072- Previously, hash() applied to an instance of a subclass of str or
1073 unicode always returned 0. This has been repaired.
1074
1075- Previously, an operation on an instance of a subclass of an
1076 immutable type (int, long, float, complex, tuple, str, unicode),
1077 where the subtype didn't override the operation (and so the
1078 operation was handled by the builtin type), could return that
1079 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001080 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001081 with the same value as s.
1082
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001083- Provisional support for pickling new-style objects has been added.
1084
Guido van Rossum808eea72001-09-25 04:15:41 +00001085Core
1086
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001087- file.writelines() now accepts any iterable object producing strings.
1088
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001089- PyUnicode_FromEncodedObject() now works very much like
1090 PyObject_Str(obj) in that it tries to use __str__/tp_str
1091 on the object if the object is not a string or buffer. This
1092 makes unicode() behave like str() when applied to non-string/buffer
1093 objects.
1094
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001095- PyFile_WriteObject now passes Unicode objects to the file's write
1096 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001097 of a print statement must support Unicode objects, i.e. they must
1098 at least convert them into ASCII strings.
1099
Guido van Rossum624c8af2001-09-18 15:21:04 +00001100- Thread scheduling on Solaris should be improved; it is no longer
1101 necessary to insert a small sleep at the start of a thread in order
1102 to let other runnable threads be scheduled.
1103
Tim Petersb07352e2001-09-08 01:25:47 +00001104Library
1105
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001106- StringIO.StringIO instances and cStringIO.StringIO instances support
1107 read character buffer compatible objects for their .write() methods.
1108 These objects are converted to strings and then handled as such
1109 by the instances.
1110
Barry Warsaw2f600732001-09-24 04:28:10 +00001111- The "email" package has been added. This is basically a port of the
1112 mimelib package <http://sf.net/projects/mimelib> with API changes
1113 and some implementations updated to use iterators and generators.
1114
Tim Peters8a9c2842001-09-22 21:30:22 +00001115- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1116 restores the ability of Tools/scripts/ndiff.py to start producing output
1117 before the entire comparison is complete.
1118
Barry Warsaw58b072d2001-09-22 04:44:21 +00001119- StringIO.StringIO instances and cStringIO.StringIO instances support
1120 iteration just like file objects (i.e. their .readline() method is
1121 called for each iteration until it returns an empty string).
1122
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001123- The codecs module has grown four new helper APIs to access
1124 builtin codecs: getencoder(), getdecoder(), getreader(),
1125 getwriter().
1126
Guido van Rossum624c8af2001-09-18 15:21:04 +00001127- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1128 simplifies writing XML RPC servers.
1129
Barry Warsaw647d5e82001-09-28 17:01:02 +00001130- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001131 after interpretation of symbolic links. On non-Unix systems, this
1132 is an alias for os.path.abspath().
1133
Tim Peters16a77ad2001-09-08 04:00:12 +00001134- operator.indexOf() (PySequence_Index() in the C API) now works with any
1135 iterable object.
1136
Guido van Rossum624c8af2001-09-18 15:21:04 +00001137- smtplib now supports various authentication and security features of
1138 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001139
Guido van Rossum624c8af2001-09-18 15:21:04 +00001140- hmac: a new module implementing keyed hashing for message
1141 authentication.
1142
1143- mimetypes now recognizes more extensions and file types. At the
1144 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001145
Guido van Rossum624c8af2001-09-18 15:21:04 +00001146- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001147 Python 2.2 bytecode generation. It has also been promoted from a
1148 Tool to a standard library package. (Tools/compiler still exists as
1149 a sample driver.)
1150
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001151Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001152
Tim Petersb07352e2001-09-08 01:25:47 +00001153Build
1154
Guido van Rossum624c8af2001-09-18 15:21:04 +00001155- Large file support (LFS) is now automatic when the platform supports
1156 it; no more manual configuration tweaks are needed. On Linux, at
1157 least, it's possible to have a system whose C library supports large
1158 files but whose kernel doesn't; in this case, large file support is
1159 still enabled but doesn't do you any good unless you upgrade your
1160 kernel or share your Python executable with another system whose
1161 kernel has large file support.
1162
1163- The configure script now supplies plausible defaults in a
1164 cross-compilation environment. This doesn't mean that the supplied
1165 values are always correct, or that cross-compilation now works
1166 flawlessly -- but it's a first step (and it shuts up most of
1167 autoconf's warnings about AC_TRY_RUN).
1168
1169- The Unix build is now a bit less chatty, courtesy of the parser
1170 generator. The build is completely silent (except for errors) when
1171 using "make -s", thanks to a -q option to setup.py.
1172
Tim Petersb07352e2001-09-08 01:25:47 +00001173C API
1174
Guido van Rossum624c8af2001-09-18 15:21:04 +00001175- The "structmember" API now supports some new flag bits to deny read
1176 and/or write access to attributes in restricted execution mode.
1177
Tim Petersb07352e2001-09-08 01:25:47 +00001178New platforms
1179
Guido van Rossum624c8af2001-09-18 15:21:04 +00001180- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1181 (http://familiar.handhelds.org).
1182
Tim Petersb07352e2001-09-08 01:25:47 +00001183Tests
1184
Tim Peters8a9c2842001-09-22 21:30:22 +00001185- The "classic" standard tests, which work by comparing stdout to
1186 an expected-output file under Lib/test/output/, no longer stop at
1187 the first mismatch. Instead the test is run to completion, and a
1188 variant of ndiff-style comparison is used to report all differences.
1189 This is much easier to understand than the previous style of reporting.
1190
1191- The unittest-based standard tests now use regrtest's test_main()
1192 convention, instead of running as a side-effect of merely being
1193 imported. This allows these tests to be run in more natural and
1194 flexible ways as unittests, outside the regrtest framework.
1195
1196- regrtest.py is much better integrated with unittest and doctest now,
1197 especially in regard to reporting errors.
1198
Tim Petersb07352e2001-09-08 01:25:47 +00001199Windows
1200
Guido van Rossum624c8af2001-09-18 15:21:04 +00001201- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001202 that support it (NTFS under Windows 2000). See "What's New in
1203 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001204
Tim Petersb07352e2001-09-08 01:25:47 +00001205
Tim Petersedc99312001-08-22 21:36:50 +00001206What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001207Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001208===========================
1209
1210Core
1211
Tim Peters9fffa3e2001-09-04 05:14:19 +00001212- Conversion of long to float now raises OverflowError if the long is too
1213 big to represent as a C double.
1214
Tim Peters32f453e2001-09-03 08:35:41 +00001215- The 3-argument builtin pow() no longer allows a third non-None argument
1216 if either of the first two arguments is a float, or if both are of
1217 integer types and the second argument is negative (in which latter case
1218 the arguments are converted to float, so this is really the same
1219 restriction).
1220
Tim Peters5d2b77c2001-09-03 05:47:38 +00001221- The builtin dir() now returns more information, and sometimes much
1222 more, generally naming all attributes of an object, and all attributes
1223 reachable from the object via its class, and from its class's base
1224 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1225 an empty list. In 2.2a3,
1226
1227 >>> dir([])
1228 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1229 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1230 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1231 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1232 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1233 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1234 'reverse', 'sort']
1235
1236 dir(module) continues to return only the module's attributes, though.
1237
Tim Petersbdee63f2001-09-02 03:40:59 +00001238- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001239 than raising OverflowError. This is a partial implementation of PEP
1240 237. You can use -Wdefault::OverflowWarning to enable a warning for
1241 this situation, and -Werror::OverflowWarning to revert to the old
1242 OverflowError exception.
1243
Guido van Rossum61c345f2001-09-04 03:26:15 +00001244- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001245 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001246 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1247 -Qold, meaning the / operator has its classic meaning and no
1248 warnings are issued. Using -Qwarn issues a run-time warning about
1249 all uses of classic division for int and long arguments; -Qwarnall
1250 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001251 (for use with fixdiv.py).
1252 [Note: the remainder of this paragraph (preserved below) became
1253 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1254 <obsolete>
1255 Using -Qnew is questionable; it turns on new division by default, but
1256 only in the __main__ module. You can usefully combine -Qwarn or
1257 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1258 warns about classic division everywhere else.
1259 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001260
Tim Petersbdee63f2001-09-02 03:40:59 +00001261- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001262 long, float, str, unicode, and tuple. (The types complex, list and
1263 dictionary can also be subclassed; this was introduced earlier.)
1264 Note that restrictions apply when subclassing immutable built-in
1265 types: you can only affect the value of the instance by overloading
1266 __new__. You can add mutable attributes, and the subclass instances
1267 will have a __dict__ attribute, but you cannot change the "value"
1268 (as implemented by the base class) of an immutable subclass instance
1269 once it is created.
1270
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001271- The dictionary constructor now takes an optional argument, a
1272 mapping-like object, and initializes the dictionary from its
1273 (key, value) pairs.
1274
Tim Petersbdee63f2001-09-02 03:40:59 +00001275- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001276 "cooperative super calls" in a multiple inheritance setting. For an
1277 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1278
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001279- A new built-in type, property, has been added. This enables the
1280 creation of "properties". These are attributes implemented by
1281 getter and setter functions (or only one of these for read-only or
1282 write-only attributes), without the need to override __getattr__.
1283 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001284
Tim Petersbdee63f2001-09-02 03:40:59 +00001285- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001286 liberalized, to allow leading zeroes. Examples of literals now
1287 legal that were SyntaxErrors before:
1288
1289 00.0 0e3 0100j 07.5 00000000000000000008.
1290
Tim Petersbdee63f2001-09-02 03:40:59 +00001291- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001292 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1293
Tim Petersedc99312001-08-22 21:36:50 +00001294Library
1295
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001296- telnetlib includes symbolic names for the options, and support for
1297 setting an option negotiation callback.
1298
Tim Petersa40c7932001-09-05 22:36:56 +00001299- The new C standard no longer requires that math libraries set errno to
1300 ERANGE on overflow. For platform libraries that exploit this new
1301 freedom, Python's overflow-checking was wholly broken. A new overflow-
1302 checking scheme attempts to repair that, but may not be reliable on all
1303 platforms (C doesn't seem to provide anything both useful and portable
1304 in this area anymore).
1305
Martin v. Löwis44f86962001-09-05 13:44:54 +00001306- Asynchronous timeout actions are available through the new class
1307 threading.Timer.
1308
Tim Peters78526162001-09-05 00:53:45 +00001309- math.log and math.log10 now return sensible results for even huge
1310 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1311
Tim Petersbdee63f2001-09-02 03:40:59 +00001312- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001313 currently held. See the docs for the imp module.
1314
Tim Petersbdee63f2001-09-02 03:40:59 +00001315- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001316 dumps containing ints written on platforms where Python ints are 8 bytes.
1317 When read on a box where Python ints are 4 bytes, such values are
1318 converted to Python longs.
1319
Tim Petersbdee63f2001-09-02 03:40:59 +00001320- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001321 code objects is no longer allowed. This plugs a security hole.
1322
Steve Purcell6091cd62001-09-06 16:05:17 +00001323- unittest.TestResult instances no longer store references to tracebacks
1324 generated by test failures. This prevents unexpected dangling references
1325 to objects that should be garbage collected between tests.
1326
Tim Petersedc99312001-08-22 21:36:50 +00001327Tools
1328
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001329- Tools/scripts/fixdiv.py has been added which can be used to fix
1330 division operators as per PEP 238.
1331
Tim Petersedc99312001-08-22 21:36:50 +00001332Build
1333
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001334- If you are an adventurous person using Mac OS X you may want to look at
1335 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1336 application, which can be used for experimenting with Carbon or Cocoa.
1337 Discussion of this on pythonmac-sig, please.
1338
Tim Peters7eea37e2001-09-04 22:08:56 +00001339C API
1340
1341- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001342
Tim Peters9fffa3e2001-09-04 05:14:19 +00001343- Note that PyLong_AsDouble can fail! This has always been true, but no
1344 callers checked for it. It's more likely to fail now, because overflow
1345 errors are properly detected now. The proper way to check:
1346
1347 double x = PyLong_AsDouble(some_long_object);
1348 if (x == -1.0 && PyErr_Occurred()) {
1349 /* The conversion failed. */
1350 }
1351
Tim Petersbdee63f2001-09-02 03:40:59 +00001352- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001353 compile but will not participate in GC. To upgrade an extension
1354 module:
1355
1356 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001357
Neil Schemenauer4042c692001-08-30 15:38:01 +00001358 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1359 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001360
Neil Schemenauer4042c692001-08-30 15:38:01 +00001361 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1362 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001363
Neil Schemenauer4042c692001-08-30 15:38:01 +00001364 - remove PyGC_HEAD_SIZE from object size calculations
1365
1366 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1367
Tim Petersbdee63f2001-09-02 03:40:59 +00001368- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001369 These can be used safely to construct string objects from a
1370 sprintf-style format string (similar to the format string supported
1371 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001372
Tim Petersedc99312001-08-22 21:36:50 +00001373New platforms
1374
Tim Petersb7da0902001-09-02 23:01:43 +00001375- Stephen Hansen contributed patches sufficient to get a clean compile
1376 under Borland C (Windows), but he reports problems running it and ran
1377 out of time to complete the port. Volunteers? Expect a MemoryError
1378 when importing the types module; this is probably shallow, and
1379 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001380
Tim Petersedc99312001-08-22 21:36:50 +00001381Tests
1382
1383Windows
1384
Tim Peters6e13a562001-09-06 00:32:15 +00001385- Large file support is now enabled on Win32 platforms as well as on
1386 Win64. This means that, for example, you can use f.tell() and f.seek()
1387 to manipulate files larger than 2 gigabytes (provided you have enough
1388 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001389 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1390 filesize limit, and large file support makes no difference there.
1391 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1392 NTFS has no practical limit on file size, and files of any size can be
1393 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001394
Tim Petersbdee63f2001-09-02 03:40:59 +00001395- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001396 points to command.com (patch from Brian Quinlan).
1397
Tim Petersedc99312001-08-22 21:36:50 +00001398
Tim Peters20f51a72001-07-21 02:31:40 +00001399What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001400Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001401===========================
1402
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001403Build
1404
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001405- Tim Peters developed a brand new Windows installer using Wise 8.1,
1406 generously donated to us by Wise Solutions.
1407
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001408- configure supports a new option --enable-unicode, with the values
1409 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1410 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001411
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001412- A new configure option --enable-framework builds a Mac OS X framework,
1413 which "make frameworkinstall" will install. This provides a starting
1414 point for more mac-like functionality, join pythonmac-sig@python.org
1415 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001416
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001417- The NeXT platform is no longer supported.
1418
1419- The `new' module is now statically linked.
1420
Tim Peters0afb6092001-08-15 06:06:44 +00001421Tools
1422
1423- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001424 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001425 the module docstring for details.
1426
Tim Peters20f51a72001-07-21 02:31:40 +00001427Tests
1428
Tim Peters5e824c32001-08-12 22:25:01 +00001429- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001430 platforms, allowing to give clearer test result output. regrtest
1431 also has optional --use/-u switch to run normally disabled tests
1432 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001433
Tim Peters20f51a72001-07-21 02:31:40 +00001434- Several new tests in the standard test suite, with special thanks to
1435 Nick Mathewson.
1436
1437Core
1438
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001439- The floor division operator // has been added as outlined in PEP
1440 238. The / operator still provides classic division (and will until
1441 Python 3.0) unless "from __future__ import division" is included, in
1442 which case the / operator will provide true division. The operator
1443 module provides truediv() and floordiv() functions. Augmented
1444 assignment variants are included, as are the equivalent overloadable
1445 methods and C API methods. See the PEP for a full discussion:
1446 <http://python.sf.net/peps/pep-0238.html>
1447
Tim Peters6cd6a822001-08-17 22:11:27 +00001448- Future statements are now effective in simulated interactive shells
1449 (like IDLE). This should "just work" by magic, but read Michael
1450 Hudson's "Future statements in simulated shells" PEP 264 for full
1451 details: <http://python.sf.net/peps/pep-0264.html>.
1452
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001453- The type/class unification (PEP 252-253) was integrated into the
1454 trunk and is not so tentative any more (the exact specification of
1455 some features is still tentative). A lot of work has done on fixing
1456 bugs and adding robustness and features (performance still has to
1457 come a long way).
1458
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001459- Warnings about a mismatch in the Python API during extension import
1460 now use the Python warning framework (which makes it possible to
1461 write filters for these warnings).
1462
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001463- A function's __dict__ (aka func_dict) will now always be a
1464 dictionary. It used to be possible to delete it or set it to None,
1465 but now both actions raise TypeErrors. It is still legal to set it
1466 to a dictionary object. Getting func.__dict__ before any attributes
1467 have been assigned now returns an empty dictionary instead of None.
1468
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001469- A new command line option, -E, was added which disables the use of
1470 all environment variables, or at least those that are specifically
1471 significant to Python. Usually those have a name starting with
1472 "PYTHON". This was used to fix a problem where the tests fail if
1473 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1474 older distribution.
1475
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001476Library
1477
Tim Peters5e824c32001-08-12 22:25:01 +00001478- New class Differ and new functions ndiff() and restore() in difflib.py.
1479 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001480 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001481
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001482- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1483 value using the minimal quoting required for the value; more
1484 reliable than using xml.sax.saxutils.escape() for attribute values.
1485
1486- Readline completion support for cmd.Cmd was added.
1487
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001488- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1489
1490- Added function threading.BoundedSemaphore()
1491
1492- Added Ka-Ping Yee's cgitb.py module.
1493
1494- The `new' module now exposes the CO_xxx flags.
1495
Martin v. Löwis560da622001-11-24 09:24:51 +00001496- The gc module offers the get_referents function.
1497
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001498New platforms
1499
1500C API
1501
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001502- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1503 which provide a cross-platform implementations for the
1504 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1505 the standard sprintf() and vsprintf() C lib APIs, these versions
1506 apply bounds checking on the used buffer which enhances protection
1507 against buffer overruns.
1508
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001509- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001510 and extensions using different Unicode widths is rendered next to
1511 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001512 will result in an ImportError. Unicode extensions writers must make
1513 sure to check the Unicode width compatibility in their extensions by
1514 using at least one of the mangled Unicode APIs in the extension.
1515
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001516- Two new flags METH_NOARGS and METH_O are available in method definition
1517 tables to simplify implementation of methods with no arguments and a
1518 single untyped argument. Calling such methods is more efficient than
1519 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1520 deprecated.
1521
Tim Petersc1731372001-08-04 08:12:36 +00001522Windows
1523
1524- "import module" now compiles module.pyw if it exists and nothing else
1525 relevant is found.
1526
Tim Peters20f51a72001-07-21 02:31:40 +00001527
Guido van Rossum55a78992001-07-17 17:22:32 +00001528What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001529Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001530===========================
1531
1532Core
Tim Petersa814db52001-05-14 07:05:58 +00001533
Tim Peters6d6c1a32001-08-02 04:15:00 +00001534- TENTATIVELY, a large amount of code implementing much of what's
1535 described in PEP 252 (Making Types Look More Like Classes) and PEP
1536 253 (Subtyping Built-in Types) was added. This will be released
1537 with Python 2.2a1. Documentation will be provided separately
1538 through http://www.python.org/2.2/. The purpose of releasing this
1539 with Python 2.2a1 is to test backwards compatibility. It is
1540 possible, though not likely, that a decision is made not to release
1541 this code as part of 2.2 final, if any serious backwards
1542 incompapatibilities are found during alpha testing that cannot be
1543 repaired.
1544
Guido van Rossum55a78992001-07-17 17:22:32 +00001545- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001546 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001547 more 'yield' statements. See PEP 255. Since this adds a new
1548 keyword to the language, this feature must be enabled by including a
1549 future statement: "from __future__ import generators" (see PEP 236).
1550 Generators will become a standard feature in a future release
1551 (probably 2.3). Without this future statement, 'yield' remains an
1552 ordinary identifier, but a warning is issued each time it is used.
1553 (These warnings currently don't conform to the warnings framework of
1554 PEP 230; we intend to fix this in 2.2a2.)
1555
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001556- The UTF-16 codec was modified to be more RFC compliant. It will now
1557 only remove BOM characters at the start of the string and then
1558 only if running in native mode (UTF-16-LE and -BE won't remove a
1559 leading BMO character).
1560
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001561- Strings now have a new method .decode() to complement the already
1562 existing .encode() method. These two methods provide direct access
1563 to the corresponding decoders and encoders of the registered codecs.
1564
1565 To enhance the usability of the .encode() method, the special
1566 casing of Unicode object return values was dropped (Unicode objects
1567 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001568
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001569 Both methods will now return whatever the codec in charge of the
1570 requested encoding returns as object, e.g. Unicode codecs will
1571 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1572 will return u"äöü"). This enables codec writer to create codecs
1573 for various simple to use conversions.
1574
1575 New codecs were added to demonstrate these new features (the .encode()
1576 and .decode() columns indicate the type of the returned objects):
1577
1578 Name | .encode() | .decode() | Description
1579 ----------------------------------------------------------------------
1580 uu | string | string | UU codec (e.g. for email)
1581 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001582 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001583 zlib | string | string | zlib compression
1584 hex | string | string | 2-byte hex codec
1585 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1586
Mark Hammond2a0af792001-05-14 03:09:36 +00001587- Some operating systems now support the concept of a default Unicode
1588 encoding for file system operations. Notably, Windows supports 'mbcs'
1589 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001590 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001591 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001592
1593 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001594 functions that return filenames (such as os.listdir()) to return Python
1595 string objects pre-encoded using the default file system encoding for
1596 the platform. As this encoding is likely to be different from Python's
1597 default encoding, converting this name to a Unicode object before passing
1598 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001599 would attempt to use its default encoding (generally ASCII) rather than
1600 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001601
Tim Petersa814db52001-05-14 07:05:58 +00001602 In general, this change simply removes surprises when working with
1603 Unicode and the file system, making these operations work as you expect,
1604 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001605 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001606
Tim Peters61dff2b2001-05-08 15:43:37 +00001607- Float (and complex) literals in source code were evaluated to full
1608 precision only when running from a .py file; the same code loaded from a
1609 .pyc (or .pyo) file could suffer numeric differences starting at about the
1610 12th significant decimal digit. For example, on a machine with IEEE-754
1611 floating arithmetic,
1612
1613 x = 9007199254740992.0
1614 print long(x)
1615
1616 printed 9007199254740992 if run directly from .py, but 9007199254740000
1617 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1618 str(float) instead of repr(float) when building code objects. marshal
1619 now uses repr(float) instead, which should reproduce floats to full
1620 machine precision (assuming the platform C float<->string I/O conversion
1621 functions are of good quality).
1622
1623 This may cause floating-point results to change in some cases, and
1624 usually for the better, but may also cause numerically unstable
1625 algorithms to break.
1626
Tim Peters2f228e72001-05-13 00:19:31 +00001627- The implementation of dicts suffers fewer collisions, which has speed
1628 benefits. However, the order in which dict entries appear in dict.keys(),
1629 dict.values() and dict.items() may differ from previous releases for a
1630 given dict. Nothing is defined about this order, so no program should
1631 rely on it. Nevertheless, it's easy to write test cases that rely on the
1632 order by accident, typically because of printing the str() or repr() of a
1633 dict to an "expected results" file. See Lib/test/test_support.py's new
1634 sortdict(dict) function for a simple way to display a dict in sorted
1635 order.
1636
Tim Peters7a3bfc32001-06-12 01:22:22 +00001637- Many other small changes to dicts were made, resulting in faster
1638 operation along the most common code paths.
1639
Guido van Rossum10315822001-05-01 20:54:30 +00001640- Dictionary objects now support the "in" operator: "x in dict" means
1641 the same as dict.has_key(x).
1642
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001643- The update() method of dictionaries now accepts generic mapping
1644 objects. Specifically the argument object must support the .keys()
1645 and __getitem__() methods. This allows you to say, for example,
1646 {}.update(UserDict())
1647
Guido van Rossum10315822001-05-01 20:54:30 +00001648- Iterators were added; this is a generalized way of providing values
1649 to a for loop. See PEP 234. There's a new built-in function iter()
1650 to return an iterator. There's a new protocol to get the next value
1651 from an iterator using the next() method (in Python) or the
1652 tp_iternext slot (in C). There's a new protocol to get iterators
1653 using the __iter__() method (in Python) or the tp_iter slot (in C).
1654 Iterating (i.e. a for loop) over a dictionary generates its keys.
1655 Iterating over a file generates its lines.
1656
Tim Petersf553f892001-05-01 20:45:31 +00001657- The following functions were generalized to work nicely with iterator
1658 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001659 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001660 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1661 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001662 join() method of strings
1663 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001664 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1665 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001666 right-hand side of assignment statements with multiple targets, such as
1667 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001668
Tim Petersd85e1022001-05-11 21:51:48 +00001669- Accessing module attributes is significantly faster (for example,
1670 random.random or os.path or yourPythonModule.yourAttribute).
1671
Tim Peterse63415e2001-05-08 04:38:29 +00001672- Comparing dictionary objects via == and != is faster, and now works even
1673 if the keys and values don't support comparisons other than ==.
1674
Tim Peters95bf9392001-05-10 08:32:44 +00001675- Comparing dictionaries in ways other than == and != is slower: there were
1676 insecurities in the dict comparison implementation that could cause Python
1677 to crash if the element comparison routines for the dict keys and/or
1678 values mutated the dicts. Making the code bulletproof slowed it down.
1679
Tim Peterseb28ef22001-06-02 05:27:19 +00001680- Collisions in dicts are resolved via a new approach, which can help
1681 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001682 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001683 faster now. Thanks to Christian Tismer for pointing out the cause and
1684 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001685
Tim Peters52e155e2001-06-16 05:42:57 +00001686- repr() is much faster for large containers (dict, list, tuple).
1687
1688
Tim Petersa814db52001-05-14 07:05:58 +00001689Library
1690
Fred Drake960fdf92001-07-20 18:38:26 +00001691- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1692 were added to the string module. These a locale-indenpendent
1693 constants, unlike letters, lowercase, and uppercase. These are now
1694 use in appropriate locations in the standard library.
1695
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001696- The flags used in dlopen calls can now be configured using
1697 sys.setdlopenflags and queried using sys.getdlopenflags.
1698
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001699- Fredrik Lundh's xmlrpclib is now a standard library module. This
1700 provides full client-side XML-RPC support. In addition,
1701 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1702 one asyncore-based). Thanks to Eric Raymond for the documentation.
1703
Guido van Rossum643d3912001-07-05 14:46:25 +00001704- The xrange() object is simplified: it no longer supports slicing,
1705 repetition, comparisons, efficient 'in' checking, the tolist()
1706 method, or the start, stop and step attributes. See PEP 260.
1707
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001708- A new function fnmatch.filter to filter lists of file names was added.
1709
Barry Warsawffd674d2001-05-22 16:00:10 +00001710- calendar.py uses month and day names based on the current locale.
1711
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001712- strop is now *really* obsolete (this was announced before with 1.6),
1713 and issues DeprecationWarning when used (except for the four items
1714 that are still imported into string.py).
1715
Tim Petersa814db52001-05-14 07:05:58 +00001716- Cookie.py now sorts key+value pairs by key in output strings.
1717
1718- pprint.isrecursive(object) didn't correctly identify recursive objects.
1719 Now it does.
1720
Tim Peters95b3f782001-05-14 18:39:41 +00001721- pprint functions now much faster for large containers (tuple, list, dict).
1722
Tim Peters7b9542a2001-06-10 23:40:19 +00001723- New 'q' and 'Q' format codes in the struct module, corresponding to C
1724 types "long long" and "unsigned long long" (on Windows, __int64). In
1725 native mode, these can be used only when the platform C compiler supports
1726 these types (when HAVE_LONG_LONG is #define'd by the Python config
1727 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001728 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1729 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001730
Guido van Rossum83213cc2001-06-12 16:48:52 +00001731- The site module installs a new built-in function 'help' that invokes
1732 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1733 it displays a message reminding the user to use 'help()' or
1734 'help(object)'.
1735
Tim Petersa814db52001-05-14 07:05:58 +00001736Tests
1737
1738- New test_mutants.py runs dict comparisons where the key and value
1739 comparison operators mutute the dicts randomly during comparison. This
1740 rapidly causes Python to crash under earlier releases (not for the faint
1741 of heart: it can also cause Win9x to freeze or reboot!).
1742
1743- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001744 pprint.isreadable() return sensible results. Also verifies that simple
1745 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001746
Tim Peters4324aa32001-05-28 22:30:08 +00001747C API
1748
1749- Removed the unused last_is_sticky argument from the internal
1750 _PyTuple_Resize(). If this affects you, you were cheating.
1751
1752
Guido van Rossum55a78992001-07-17 17:22:32 +00001753======================================================================
1754
1755
Guido van Rossumffe13be2001-04-16 18:46:45 +00001756What's New in Python 2.1 (final)?
1757=================================
1758
1759We only changed a few things since the last release candidate, all in
1760Python library code:
1761
1762- A bug in the locale module was fixed that affected locales which
1763 define no grouping for numeric formatting.
1764
1765- A few bugs in the weakref module's implementations of weak
1766 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1767 and the test suite was updated to check for these bugs.
1768
1769- An old bug in the os.path.walk() function (introduced in Python
1770 2.0!) was fixed: a non-existent file would cause an exception
1771 instead of being ignored.
1772
1773- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1774 PyChecker.
1775
1776
Guido van Rossum5b08f132001-04-16 02:05:23 +00001777What's New in Python 2.1c2?
1778===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001779
Guido van Rossum5b08f132001-04-16 02:05:23 +00001780A flurry of small changes, and one showstopper fixed in the nick of
1781time made it necessary to release another release candidate. The list
1782here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001783
Guido van Rossum5b08f132001-04-16 02:05:23 +00001784Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001785
Guido van Rossum5b08f132001-04-16 02:05:23 +00001786- Tim discovered a nasty bug in the dictionary code, caused by
1787 PyDict_Next() calling dict_resize(), and the GC code's use of
1788 PyDict_Next() violating an assumption in dict_items(). This was
1789 fixed with considerable amounts of band-aid, but the net effect is a
1790 saner and more robust implementation.
1791
1792- Made a bunch of symbols static that were accidentally global.
1793
1794Build and Ports
1795
1796- The setup.py script didn't check for a new enough version of zlib
1797 (1.1.3 is needed). Now it does.
1798
1799- Changed "make clean" target to also remove shared libraries.
1800
1801- Added a more general warning about the SGI Irix optimizer to README.
1802
1803Library
1804
1805- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1806 omitted the slash between host and file.html.
1807
1808- The mailbox module's _Mailbox class contained a completely broken
1809 and undocumented seek() method. Ripped it out.
1810
1811- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1812 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1813
1814- Fixed a few last-minute bugs in unittest.
1815
1816Extensions
1817
1818- Reverted the patch to the OpenSSL code in socketmodule.c to support
1819 RAND_status() and the EGD, and the subsequent patch that tried to
1820 fix it for pre-0.9.5 versions; the problem with the patch is that on
1821 some systems it issues a warning whenever socket is imported, and
1822 that's unacceptable.
1823
1824Tests
1825
1826- Fixed the pickle tests to work with "import test.test_pickle".
1827
1828- Tweaked test_locale.py to actually run the test Windows.
1829
1830- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1831 not "wb" (which is not a valid mode at all).
1832
1833- Fix pstats browser crashes. Import readline if it exists to make
1834 the user interface nicer.
1835
1836- Add "import thread" to the top of test modules that import the
1837 threading module (test_asynchat and test_threadedtempfile). This
1838 prevents test failures caused by a broken threading module resulting
1839 from a previously caught failed import.
1840
1841- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1842 needed on some platforms (e.g. Solaris 8) when the tests are run
1843 twice in succession.
1844
1845- Skip rather than fail test_sunaudiodev if no audio device is found.
1846
1847
1848What's New in Python 2.1c1?
1849===========================
1850
1851This list was significantly updated when 2.1c2 was released; the 2.1c1
1852release didn't mention most changes that were actually part of 2.1c1:
1853
1854Legal
1855
1856- Copyright was assigned to the Python Software Foundation (PSF) and a
1857 PSF license (very similar to the CNRI license) was added.
1858
1859- The CNRI copyright notice was updated to include 2001.
1860
1861Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001862
Guido van Rossumc9932722001-04-12 02:31:27 +00001863- After a public outcry, assignment to __debug__ is no longer illegal;
1864 instead, a warning is issued. It will become illegal in 2.2.
1865
Guido van Rossum5b08f132001-04-16 02:05:23 +00001866- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1867 "%#x" now always prepends "0x", even if the value is zero.
1868
1869- Fixed some nits in the bytecode compiler.
1870
1871- Fixed core dumps when calling certain kinds of non-functions.
1872
1873- Fixed various core dumps caused by reference count bugs.
1874
1875Build and Ports
1876
1877- Use INSTALL_SCRIPT to install script files.
1878
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001879- New port: SCO Unixware 7, by Billy G. Allie.
1880
Guido van Rossum5b08f132001-04-16 02:05:23 +00001881- Updated RISCOS port.
1882
1883- Updated BeOS port and notes.
1884
1885- Various other porting problems resolved.
1886
1887Library
1888
1889- The TERMIOS and SOCKET modules are now truly obsolete and
1890 unnecessary. Their symbols are incorporated in the termios and
1891 socket modules.
1892
1893- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1894 better tests for pickling.
1895
1896- threading: make Condition.wait() robust against KeyboardInterrupt.
1897
1898- zipfile: add support to zipfile to support opening an archive
1899 represented by an open file rather than a file name. Fix bug where
1900 the archive was not properly closed. Fixed a bug in this bugfix
1901 where flush() was called for a read-only file.
1902
1903- imputil: added an uninstall() method to the ImportManager.
1904
1905- Canvas: fixed bugs in lower() and tkraise() methods.
1906
1907- SocketServer: API change (added overridable close_request() method)
1908 so that the TCP server can explicitly close the request.
1909
1910- pstats: Eric Raymond added a simple interactive statistics browser,
1911 invoked when the module is run as a script.
1912
1913- locale: fixed a problem in format().
1914
1915- webbrowser: made it work when the BROWSER environment variable has a
1916 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1917 KDE 2. Fixed some other nits.
1918
1919- unittest: changes to allow using a different exception than
1920 AssertionError, and added a few more function aliases. Some other
1921 small changes.
1922
1923- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1924
1925- asynchat: fixed a critical bug in asynchat that slipped through the
1926 2.1b2 release. Fixed another rare bug.
1927
1928- Fix some unqualified except: clauses (always a bad code example).
1929
1930XML
1931
1932- pyexpat: new API get_version_string().
1933
1934- Fixed some minidom bugs.
1935
1936Extensions
1937
1938- Fixed a core dump in _weakref. Removed the weakref.mapping()
1939 function (it adds nothing to the API).
1940
1941- Rationalized the use of header files in the readline module, to make
1942 it compile (albeit with some warnings) with the very recent readline
1943 4.2, without breaking for earlier versions.
1944
1945- Hopefully fixed a buffering problem in linuxaudiodev.
1946
1947- Attempted a fix to make the OpenSSL support in the socket module
1948 work again with pre-0.9.5 versions of OpenSSL.
1949
1950Tests
1951
1952- Added a test case for asynchat and asyncore.
1953
1954- Removed coupling between tests where one test failing could break
1955 another.
1956
1957Tools
1958
1959- Ping added an interactive help browser to pydoc, fixed some nits
1960 in the rest of the pydoc code, and added some features to his
1961 inspect module.
1962
1963- An updated python-mode.el version 4.1 which integrates Ken
1964 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1965 much nicer in XEmacs and Emacs. When stepping through your program
1966 with pdb, in either the shell window or the *Python* window, the
1967 source file and line will be tracked by an arrow. Very cool!
1968
1969- IDLE: syntax warnings in interactive mode are changed into errors.
1970
1971- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001972 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001973
1974- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001975
Barry Warsaw11e89c72001-04-11 20:37:57 +00001976
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001977What's New in Python 2.1 beta 2?
1978================================
1979
Guido van Rossum053ae352001-03-22 14:17:21 +00001980(Unlisted are many fixed bugs, more documentation, etc.)
1981
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001982Core language, builtins, and interpreter
1983
Guido van Rossum053ae352001-03-22 14:17:21 +00001984- The nested scopes work (enabled by "from __future__ import
1985 nested_scopes") is completed; in particular, the future now extends
1986 into code executed through exec, eval() and execfile(), and into the
1987 interactive interpreter.
1988
1989- When calling a base class method (e.g. BaseClass.__init__(self)),
1990 this is now allowed even if self is not strictly spoken a class
1991 instance (e.g. when using metaclasses or the Don Beaudry hook).
1992
1993- Slice objects are now comparable but not hashable; this prevents
1994 dict[:] from being accepted but meaningless.
1995
1996- Complex division is now calculated using less braindead algorithms.
1997 This doesn't change semantics except it's more likely to give useful
1998 results in extreme cases. Complex repr() now uses full precision
1999 like float repr().
2000
2001- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2002
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002003- It is illegal to assign to the name __debug__, which is set when the
2004 interpreter starts. It is effectively a compile-time constant.
2005
2006- A warning will be issued if a global statement for a variable
2007 follows a use or assignment of that variable.
2008
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002009Standard library
2010
Guido van Rossum053ae352001-03-22 14:17:21 +00002011- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2012 inspired by JUnit), is now part of the standard library. You now
2013 have a choice of two testing frameworks: unittest requires you to
2014 write testcases as separate code, doctest gathers them from
2015 docstrings. Both approaches have their advantages and
2016 disadvantages.
2017
2018- A new module Tix was added, which wraps the Tix extension library
2019 for Tk. With that module, it is not necessary to statically link
2020 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2021 require" command. See Demo/tix/.
2022
2023- tzparse.py is now obsolete.
2024
2025- In gzip.py, the seek() and tell() methods are removed -- they were
2026 non-functional anyway, and it's better if callers can test for their
2027 existence with hasattr().
2028
2029Python/C API
2030
2031- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2032 that's already in the dictionary during a PyDict_Next() iteration.
2033 This used to fail occasionally when a dictionary resize operation
2034 could be triggered that would rehash all the keys. All other
2035 modifications to the dictionary are still off-limits during a
2036 PyDict_Next() iteration!
2037
2038- New extended APIs related to passing compiler variables around.
2039
2040- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2041 implement isinstance() and issubclass().
2042
2043- Py_BuildValue() now has a "D" conversion to create a Python complex
2044 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002045
Fred Drake4e262a92001-03-22 18:26:47 +00002046- Extensions types which support weak references must now set the
2047 field allocated for the weak reference machinery to NULL themselves;
2048 this is done to avoid the cost of checking each object for having a
2049 weakly referencable type in PyObject_INIT(), since most types are
2050 not weakly referencable.
2051
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002052- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2053 free variables and cell variables to and from the frame's f_locals.
2054
2055- Variants of several functions defined in pythonrun.h have been added
2056 to support the nested_scopes future statement. The variants all end
2057 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2058 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2059 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002060 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002061
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002062Distutils
2063
2064- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2065 into the release tree.
2066
Tim Peters0e57abf2001-05-02 07:39:38 +00002067- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002068 (an uninstaller, more customization of the installer's display)
2069
2070- from Jack Jansen: added Mac-specific code to generate a dialog for
2071 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002072 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002073 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002074
2075- added 'platforms' and 'keywords' to the set of metadata that can be
2076 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002077
2078- applied patches from Jason Tishler to make the compiler class work with
2079 Cygwin.
2080
2081
Tim Peters2fe289a2001-03-01 22:19:38 +00002082What's New in Python 2.1 beta 1?
2083================================
Tim Petersd66595f2001-02-04 03:09:53 +00002084
2085Core language, builtins, and interpreter
2086
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002087- Following an outcry from the community about the amount of code
2088 broken by the nested scopes feature introduced in 2.1a2, we decided
2089 to make this feature optional, and to wait until Python 2.2 (or at
2090 least 6 months) to make it standard. The option can be enabled on a
2091 per-module basis by adding "from __future__ import nested_scopes" at
2092 the beginning of a module (before any other statements, but after
2093 comments and an optional docstring). See PEP 236 (Back to the
2094 __future__) for a description of the __future__ statement. PEP 227
2095 (Statically Nested Scopes) has been updated to reflect this change,
2096 and to clarify the semantics in a number of endcases.
2097
2098- The nested scopes code, when enabled, has been hardened, and most
2099 bugs and memory leaks in it have been fixed.
2100
2101- Compile-time warnings are now generated for a number of conditions
2102 that will break or change in meaning when nested scopes are enabled:
2103
2104 - Using "from...import *" or "exec" without in-clause in a function
2105 scope that also defines a lambda or nested function with one or
2106 more free (non-local) variables. The presence of the import* or
2107 bare exec makes it impossible for the compiler to determine the
2108 exact set of local variables in the outer scope, which makes it
2109 impossible to determine the bindings for free variables in the
2110 inner scope. To avoid the warning about import *, change it into
2111 an import of explicitly name object, or move the import* statement
2112 to the global scope; to avoid the warning about bare exec, use
2113 exec...in... (a good idea anyway -- there's a possibility that
2114 bare exec will be deprecated in the future).
2115
2116 - Use of a global variable in a nested scope with the same name as a
2117 local variable in a surrounding scope. This will change in
2118 meaning with nested scopes: the name in the inner scope will
2119 reference the variable in the outer scope rather than the global
2120 of the same name. To avoid the warning, either rename the outer
2121 variable, or use a global statement in the inner function.
2122
Neil Schemenauera35c6882001-02-27 04:45:05 +00002123- An optional object allocator has been included. This allocator is
2124 optimized for Python objects and should be faster and use less memory
2125 than the standard system allocator. It is not enabled by default
2126 because of possible thread safety problems. The allocator is only
2127 protected by the Python interpreter lock and it is possible that some
2128 extension modules require a thread safe allocator. The object
2129 allocator can be enabled by providing the "--with-pymalloc" option to
2130 configure.
2131
Tim Petersd66595f2001-02-04 03:09:53 +00002132Standard library
2133
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002134- pyexpat now detects the expat version if expat.h defines it. A
2135 number of additional handlers are provided, which are only available
2136 since expat 1.95. In addition, the methods SetParamEntityParsing and
2137 GetInputContext of Parser objects are available with 1.95.x
2138 only. Parser objects now provide the ordered_attributes and
2139 specified_attributes attributes. A new module expat.model was added,
2140 which offers a number of additional constants if 1.95.x is used.
2141
2142- xml.dom offers the new functions registerDOMImplementation and
2143 getDOMImplementation.
2144
2145- xml.dom.minidom offers a toprettyxml method. A number of DOM
2146 conformance issues have been resolved. In particular, Element now
2147 has an hasAttributes method, and the handling of namespaces was
2148 improved.
2149
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002150- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2151 getting information about live Python code, and pydoc.py, a module
2152 for interactively converting docstrings to HTML or text.
2153 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002154 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002155 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2156 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002157
Tim Peters1eff7962001-03-01 02:31:33 +00002158- New library module difflib.py, primarily packaging the SequenceMatcher
2159 class at the heart of the popular ndiff.py file-comparison tool.
2160
2161- doctest.py (a framework for verifying Python code examples in docstrings)
2162 is now part of the std library.
2163
Tim Petersd66595f2001-02-04 03:09:53 +00002164Windows changes
2165
Guido van Rossume3955a82001-03-02 14:05:59 +00002166- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2167 small GUI that lets you browse the module docstrings using your
2168 default web browser.
2169
Tim Peters1eff7962001-03-01 02:31:33 +00002170- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2171 Platforms) is implemented. See
2172
2173 http://python.sourceforge.net/peps/pep-0235.html
2174
2175 for full details, especially the "Current Lower-Left Semantics" section.
2176 The new Windows import rules are simpler than before:
2177
2178 A. If the PYTHONCASEOK environment variable exists, same as
2179 before: silently accept the first case-insensitive match of any
2180 kind; raise ImportError if none found.
2181
2182 B. Else search sys.path for the first case-sensitive match; raise
2183 ImportError if none found.
2184
2185 The same rules have been implented on other platforms with case-
2186 insensitive but case-preserving filesystems too (including Cygwin, and
2187 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002188
Tim Peters25a9ce32001-02-19 07:06:36 +00002189- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2190 what it's supposed to do (and does do under NT and 2000) via direct
2191 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002192 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002193 all Win9x systems before.
2194
Tim Peters1eff7962001-03-01 02:31:33 +00002195- Build: Subproject _test (effectively) renamed to _testcapi.
2196
Tim Peters2fe289a2001-03-01 22:19:38 +00002197New platforms
2198
2199- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2200 Thanks to Steven Majewski!
2201
2202- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2203 Tishler!
2204
Guido van Rossum9089b272001-03-02 06:49:50 +00002205- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2206 Schwertberger! See RISCOS/README for more information -- it seems
2207 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002208 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002209
Tim Peters25a9ce32001-02-19 07:06:36 +00002210
Tim Petersd7b5e882001-01-25 03:36:26 +00002211What's New in Python 2.1 alpha 2?
2212=================================
Tim Peters40ead762001-01-27 05:35:26 +00002213
Tim Petersd7b5e882001-01-25 03:36:26 +00002214Core language, builtins, and interpreter
2215
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002216- Scopes nest. If a name is used in a function or class, but is not
2217 local, the definition in the nearest enclosing function scope will
2218 be used. One consequence of this change is that lambda statements
2219 could reference variables in the namespaces where the lambda is
2220 defined. In some unusual cases, this change will break code.
2221
2222 In all previous version of Python, names were resolved in exactly
2223 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002224 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002225 function A is defined within a function B, the names bound in B are
2226 not visible in A. The new rules make names bound in B visible in A,
2227 unless A contains a name binding that hides the binding in B.
2228
2229 Section 4.1 of the reference manual describes the new scoping rules
2230 in detail. The test script in Lib/test/test_scope.py demonstrates
2231 some of the effects of the change.
2232
2233 The new rules will cause existing code to break if it defines nested
2234 functions where an outer function has local variables with the same
2235 name as globals or builtins used by the inner function. Example:
2236
2237 def munge(str):
2238 def helper(x):
2239 return str(x)
2240 if type(str) != type(''):
2241 str = helper(str)
2242 return str.strip()
2243
2244 Under the old rules, the name str in helper() is bound to the
2245 builtin function str(). Under the new rules, it will be bound to
2246 the argument named str and an error will occur when helper() is
2247 called.
2248
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002249- The compiler will report a SyntaxError if "from ... import *" occurs
2250 in a function or class scope. The language reference has documented
2251 that this case is illegal, but the compiler never checked for it.
2252 The recent introduction of nested scope makes the meaning of this
2253 form of name binding ambiguous. In a future release, the compiler
2254 may allow this form when there is no possibility of ambiguity.
2255
Tim Peters40ead762001-01-27 05:35:26 +00002256- repr(string) is easier to read, now using hex escapes instead of octal,
2257 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2258
2259 >>> "\texample \r\n" + chr(0) + chr(255)
2260 '\texample \r\n\x00\xff' # in 2.1
2261 '\011example \015\012\000\377' # in 2.0
2262
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002263- Functions are now compared and hashed by identity, not by value, since
2264 the func_code attribute is writable.
2265
Fred Drakefb9d7122001-02-01 20:00:40 +00002266- Weak references (PEP 205) have been added. This involves a few
2267 changes in the core, an extension module (_weakref), and a Python
2268 module (weakref). The weakref module is the public interface. It
2269 includes support for "explicit" weak references, proxy objects, and
2270 mappings with weakly held values.
2271
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002272- A 'continue' statement can now appear in a try block within the body
2273 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002274 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002275
Tim Petersd7b5e882001-01-25 03:36:26 +00002276Standard library
2277
Barry Warsaw30dbd142001-01-31 22:14:01 +00002278- mailbox.py now has a new class, PortableUnixMailbox which is
2279 identical to UnixMailbox but uses a more portable scheme for
2280 determining From_ separators. Also, the constructors for all the
2281 classes in this module have a new optional `factory' argument, which
2282 is a callable used when new message classes must be instantiated by
2283 the next() method.
2284
Tim Petersd7b5e882001-01-25 03:36:26 +00002285- random.py is now self-contained, and offers all the functionality of
2286 the now-deprecated whrandom.py. See the docs for details. random.py
2287 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002288 and restoring the internal state of the generator; and jumpahead(n),
2289 for quickly forcing the internal state to be the same as if n calls to
2290 random() had been made. The latter is particularly useful for multi-
2291 threaded programs, creating one instance of the random.Random() class for
2292 each thread, then using .jumpahead() to force each instance to use a
2293 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002294
Tim Peters0de88fc2001-02-01 04:59:18 +00002295- random.py's seed() function is new. For bit-for-bit compatibility with
2296 prior releases, use the whseed function instead. The new seed function
2297 addresses two problems: (1) The old function couldn't produce more than
2298 about 2**24 distinct internal states; the new one about 2**45 (the best
2299 that can be done in the Wichmann-Hill generator). (2) The old function
2300 sometimes produced identical internal states when passed distinct
2301 integers, and there was no simple way to predict when that would happen;
2302 the new one guarantees to produce distinct internal states for all
2303 arguments in [0, 27814431486576L).
2304
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002305- The socket module now supports raw packets on Linux. The socket
2306 family is AF_PACKET.
2307
Tim Peters9ea17ac2001-02-02 05:57:15 +00002308- test_capi.py is a start at running tests of the Python C API. The tests
2309 are implemented by the new Modules/_testmodule.c.
2310
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002311- A new extension module, _symtable, provides provisional access to the
2312 internal symbol table used by the Python compiler. A higher-level
2313 interface will be added on top of _symtable in a future release.
2314
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002315- Removed the obsolete soundex module.
2316
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002317- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2318 the isSameNode method; NamedNodeMap the get method.
2319
2320- xml.sax.expatreader supports the lexical handler property; it
2321 generates comment, startCDATA, and endCDATA events.
2322
Tim Petersee826f82001-01-31 19:39:44 +00002323Windows changes
2324
2325- Build procedure: the zlib project is built in a different way that
2326 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002327 the zlib binary used. See PCbuild\readme.txt for details. Your old
2328 zlib-related directories can be deleted; you'll need to download fresh
2329 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002330
Tim Peters9ea17ac2001-02-02 05:57:15 +00002331- Build: New subproject _test for the benefit of test_capi.py (see above).
2332
Tim Petersb16c56f2001-02-02 21:24:51 +00002333- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2334 interface to some Python compiler internals).
2335
2336- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002337 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002338
Tim Petersa3a3a032000-11-30 05:22:44 +00002339What's New in Python 2.1 alpha 1?
2340=================================
2341
2342Core language, builtins, and interpreter
2343
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002344- There is a new Unicode companion to the PyObject_Str() API
2345 called PyObject_Unicode(). It behaves in the same way as the
2346 former, but assures that the returned value is an Unicode object
2347 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002348
Guido van Rossumf98eda02001-01-17 15:54:45 +00002349- The comparison operators support "rich comparison overloading" (PEP
2350 207). C extension types can provide a rich comparison function in
2351 the new tp_richcompare slot in the type object. The cmp() function
2352 and the C function PyObject_Compare() first try the new rich
2353 comparison operators before trying the old 3-way comparison. There
2354 is also a new C API PyObject_RichCompare() (which also falls back on
2355 the old 3-way comparison, but does not constrain the outcome of the
2356 rich comparison to a Boolean result).
2357
2358 The rich comparison function takes two objects (at least one of
2359 which is guaranteed to have the type that provided the function) and
2360 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2361 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2362 object, which may be NotImplemented (in which case the tp_compare
2363 slot function is used as a fallback, if defined).
2364
2365 Classes can overload individual comparison operators by defining one
2366 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002367 __ge__. There are no explicit "reflected argument" versions of
2368 these; instead, __lt__ and __gt__ are each other's reflection,
2369 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2370 reflection (similar at the C level). No other implications are
2371 made; in particular, Python does not assume that == is the Boolean
2372 inverse of !=, or that < is the Boolean inverse of >=. This makes
2373 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002374
2375 Classes or types that want to implement (in)equality tests but not
2376 the ordering operators (i.e. unordered types) should implement ==
2377 and !=, and raise an error for the ordering operators.
2378
Guido van Rossuma88479f2001-01-18 14:28:08 +00002379 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002380 Boolean; e.g. a matrix type might want to return a matrix of bits
2381 for A < B, giving elementwise comparisons. Such types should ensure
2382 that any interpretation of their value in a Boolean context raises
2383 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2384 at the C level) to always raise an exception.
2385
Guido van Rossuma88479f2001-01-18 14:28:08 +00002386- Complex numbers use rich comparisons to define == and != but raise
2387 an exception for <, <=, > and >=. Unfortunately, this also means
2388 that cmp() of two complex numbers raises an exception when the two
2389 numbers differ. Since it is not mathematically meaningful to compare
2390 complex numbers except for equality, I hope that this doesn't break
2391 too much code.
2392
Tim Peters3389f192001-02-18 08:48:49 +00002393- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002394 not defined by the language, other than that it's arbitrary but
2395 consistent (see the Reference Manual). An implementation detail changed
2396 in 2.1a1 such that None now compares less than any other object. Code
2397 relying on this new behavior (like code that relied on the previous
2398 behavior) does so at its own risk.
2399
Barry Warsaw573b5412001-01-15 20:43:18 +00002400- Functions and methods now support getting and setting arbitrarily
2401 named attributes (PEP 232). Functions have a new __dict__
2402 (a.k.a. func_dict) which hold the function attributes. Methods get
2403 and set attributes on their underlying im_func. It is a TypeError
2404 to set an attribute on a bound method.
2405
Guido van Rossum051e3352001-01-15 19:11:10 +00002406- The xrange() object implementation has been improved so that
2407 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2408 limitation that in this case len(xrange(sys.maxint)) can't be
2409 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2410 work fine as long as the index i doesn't actually reach 2**31.
2411 (Python uses regular ints for sequence and string indices; fixing
2412 that is much more work.)
2413
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002414- Two changes to from...import:
2415
Guido van Rossumba381232001-02-03 15:06:40 +00002416 1) "from M import X" now works even if (after loading module M)
2417 sys.modules['M'] is not a real module; it's basically a getattr()
2418 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002419
2420 2) "from M import *" now looks for M.__all__ to decide which names to
2421 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2422 filters out names starting with '_' as before. Whether or not
2423 __all__ exists, there's no restriction on the type of M.
2424
Guido van Rossumf61f1662001-01-10 20:13:55 +00002425- File objects have a new method, xreadlines(). This is the fastest
2426 way to iterate over all lines in a file:
2427
2428 for line in file.xreadlines():
2429 ...do something to line...
2430
2431 See the xreadlines module (mentioned below) for how to do this for
2432 other file-like objects.
2433
2434- Even if you don't use file.xreadlines(), you may expect a speedup on
2435 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002436 quite a bit in platform-specific ways: on systems (like Linux) that
2437 support flockfile(), getc_unlocked(), and funlockfile(), those are
2438 used by default. On systems (like Windows) without getc_unlocked(),
2439 a complicated (but still thread-safe) method using fgets() is used by
2440 default.
2441
Tim Petersd52269b2001-01-25 06:23:18 +00002442 You can force use of the fgets() method by #define'ing
2443 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002444 getc_unlocked()).
2445
Tim Petersd52269b2001-01-25 06:23:18 +00002446 You can force fgets() not to be used by #define'ing
2447 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002448 test_bufio.py fails -- and let us know if it does!).
2449
2450- In addition, the fileinput module, while still slower than the other
2451 methods on most platforms, has been sped up too, by using
2452 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002453
2454- Support for run-time warnings has been added, including a new
2455 command line option (-W) to specify the disposition of warnings.
2456 See the description of the warnings module below.
2457
2458- Extensive changes have been made to the coercion code. This mostly
2459 affects extension modules (which can now implement mixed-type
2460 numerical operators without having to use coercion), but
2461 occasionally, in boundary cases the coercion semantics have changed
2462 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002463 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002464 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002465 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002466
Guido van Rossumf98eda02001-01-17 15:54:45 +00002467- In connection with the coercion changes, a new built-in singleton
2468 object, NotImplemented is defined. This can be returned for
2469 operations that wish to indicate they are not implemented for a
2470 particular combination of arguments. From C, this is
2471 Py_NotImplemented.
2472
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002473- The interpreter accepts now bytecode files on the command line even
2474 if they do not have a .pyc or .pyo extension. On Linux, after executing
2475
Martin v. Löwise214baa2001-02-04 22:37:56 +00002476import imp,sys,string
2477magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2478reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2479open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002480
2481 any byte code file can be used as an executable (i.e. as an argument
2482 to execve(2)).
2483
Tim Peters9940b802000-12-01 07:59:35 +00002484- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002485 character. In 1.6 and earlier, they never produced a sign,
2486 and raised an error if the value of the long was too large
2487 to fit in a Python int. In 2.0, they produced a sign if and
2488 only if too large to fit in an int. This was inconsistent
2489 across platforms (because the size of an int varies across
2490 platforms), and inconsistent with hex() and oct(). Example:
2491
2492 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002493 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002494 'ffffffbe' # in 2.0 and before, on 32-bit machines
2495 >>> hex(-0x42L)
2496 '-0x42L' # in all versions of Python
2497
Tim Peters9940b802000-12-01 07:59:35 +00002498 The behavior of %d formats for negative Python longs remains
2499 the same as in 2.0 (although in 1.6 and before, they raised
2500 an error if the long didn't fit in a Python int).
2501
2502 %u formats don't make sense for Python longs, but are allowed
2503 and treated the same as %d in 2.1. In 2.0, a negative long
2504 formatted via %u produced a sign if and only if too large to
2505 fit in an int. In 1.6 and earlier, a negative long formatted
2506 via %u raised an error if it was too big to fit in an int.
2507
Guido van Rossum3661d392000-12-12 22:10:31 +00002508- Dictionary objects have an odd new method, popitem(). This removes
2509 an arbitrary item from the dictionary and returns it (in the form of
2510 a (key, value) pair). This can be useful for algorithms that use a
2511 dictionary as a bag of "to do" items and repeatedly need to pick one
2512 item. Such algorithms normally end up running in quadratic time;
2513 using popitem() they can usually be made to run in linear time.
2514
Tim Peters36cdad12000-12-29 02:06:45 +00002515Standard library
2516
Thomas Woutersfe385252001-01-19 23:16:56 +00002517- In the time module, the time argument to the functions strftime,
2518 localtime, gmtime, asctime and ctime is now optional, defaulting to
2519 the current time (in the local timezone).
2520
Guido van Rossumda91f222001-01-15 16:36:08 +00002521- The ftplib module now defaults to passive mode, which is deemed a
2522 more useful default given that clients are often inside firewalls
2523 these days. Note that this could break if ftplib is used to connect
2524 to a *server* that is inside a firewall, from outside; this is
2525 expected to be a very rare situation. To fix that, you can call
2526 ftp.set_pasv(0).
2527
Martin v. Löwis10a27872001-01-13 09:54:41 +00002528- The module site now treats .pth files not only for path configuration,
2529 but also supports extensions to the initialization code: Lines starting
2530 with import are executed.
2531
Guido van Rossumf61f1662001-01-10 20:13:55 +00002532- There's a new module, warnings, which implements a mechanism for
2533 issuing and filtering warnings. There are some new built-in
2534 exceptions that serve as warning categories, and a new command line
2535 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2536 turns warnings into errors). warnings.warn(message[, category])
2537 issues a warning message; this can also be called from C as
2538 PyErr_Warn(category, message).
2539
2540- A new module xreadlines was added. This exports a single factory
2541 function, xreadlines(). The intention is that this code is the
2542 absolutely fastest way to iterate over all lines in an open
2543 file(-like) object:
2544
2545 import xreadlines
2546 for line in xreadlines.xreadlines(file):
2547 ...do something to line...
2548
2549 This is equivalent to the previous the speed record holder using
2550 file.readlines(sizehint). Note that if file is a real file object
2551 (as opposed to a file-like object), this is equivalent:
2552
2553 for line in file.xreadlines():
2554 ...do something to line...
2555
Tim Peters36cdad12000-12-29 02:06:45 +00002556- The bisect module has new functions bisect_left, insort_left,
2557 bisect_right and insort_right. The old names bisect and insort
2558 are now aliases for bisect_right and insort_right. XXX_right
2559 and XXX_left methods differ in what happens when the new element
2560 compares equal to one or more elements already in the list: the
2561 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002562 right. Code that doesn't care where equal elements end up should
2563 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002564
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002565- The new curses.panel module wraps the panel library that forms part
2566 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2567
Guido van Rossumf61f1662001-01-10 20:13:55 +00002568- The SocketServer module now sets the allow_reuse_address flag by
2569 default in the TCPServer class.
2570
2571- A new function, sys._getframe(), returns the stack frame pointer of
2572 the caller. This is intended only as a building block for
2573 higher-level mechanisms such as string interpolation.
2574
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002575- The pyexpat module supports a number of new handlers, which are
2576 available only in expat 1.2. If invocation of a callback fails, it
2577 will report an additional frame in the traceback. Parser objects
2578 participate now in garbage collection. If expat reports an unknown
2579 encoding, pyexpat will try to use a Python codec; that works only
2580 for single-byte charsets. The parser type objects is exposed as
2581 XMLParserObject.
2582
2583- xml.dom now offers standard definitions for symbolic node type and
2584 exception code constants, and a hierarchy of DOM exceptions. minidom
2585 was adjusted to use them.
2586
2587- The conformance of xml.dom.minidom to the DOM specification was
2588 improved. It detects a number of additional error cases; the
2589 previous/next relationship works even when the tree is modified;
2590 Node supports the normalize() method; NamedNodeMap, DocumentType and
2591 DOMImplementation classes were added; Element supports the
2592 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2593 method.
2594
Guido van Rossumf61f1662001-01-10 20:13:55 +00002595Build issues
2596
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002597- For Unix (and Unix-compatible) builds, configuration and building of
2598 extension modules is now greatly automated. Rather than having to
2599 edit the Modules/Setup file to indicate which modules should be
2600 built and where their include files and libraries are, a
2601 distutils-based setup.py script now takes care of building most
2602 extension modules. All extension modules built this way are built
2603 as shared libraries. Only a few modules that must be linked
2604 statically are still listed in the Setup file; you won't need to
2605 edit their configuration.
2606
2607- Python should now build out of the box on Cygwin. If it doesn't,
2608 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002609
2610- Python now always uses its own (renamed) implementation of getopt()
2611 -- there's too much variation among C library getopt()
2612 implementations.
2613
2614- C++ compilers are better supported; the CXX macro is always set to a
2615 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002616
Tim Petersd92dfe02000-12-12 01:18:41 +00002617Windows changes
2618
2619- select module: By default under Windows, a select() call
2620 can specify no more than 64 sockets. Python now boosts
2621 this Microsoft default to 512. If you need even more than
2622 that, see the MS docs (you'll need to #define FD_SETSIZE
2623 and recompile Python from source).
2624
Guido van Rossumf61f1662001-01-10 20:13:55 +00002625- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2626 subdirectory is no more!
2627
Tim Petersa3a3a032000-11-30 05:22:44 +00002628
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002629What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002630=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002631
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002632Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002633changes are in the file HISTORY. If you are making the jump directly
2634from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2635HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002636
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002637Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2638the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2639http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002640
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002641--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002642
2643======================================================================
2644
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002645What's new in 2.0 (since release candidate 1)?
2646==============================================
2647
2648Standard library
2649
2650- The copy_reg module was modified to clarify its intended use: to
2651 register pickle support for extension types, not for classes.
2652 pickle() will raise a TypeError if it is passed a class.
2653
2654- Fixed a bug in gettext's "normalize and expand" code that prevented
2655 it from finding an existing .mo file.
2656
2657- Restored support for HTTP/0.9 servers in httplib.
2658
Tim Peters989b7b92000-10-16 20:24:53 +00002659- The math module was changed to stop raising OverflowError in case of
2660 underflow, and return 0 instead in underflow cases. Whether Python
2661 used to raise OverflowError in case of underflow was platform-
2662 dependent (it did when the platform math library set errno to ERANGE
2663 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002664
2665- Fixed a bug in StringIO that occurred when the file position was not
2666 at the end of the file and write() was called with enough data to
2667 extend past the end of the file.
2668
2669- Fixed a bug that caused Tkinter error messages to get lost on
2670 Windows. The bug was fixed by replacing direct use of
2671 interp->result with Tcl_GetStringResult(interp).
2672
2673- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2674 redirect response.
2675
2676- Several changes were made to distutils: Some debugging code was
2677 removed from util. Fixed the installer used when an external zip
2678 program (like WinZip) is not found; the source code for this
2679 installer is in Misc/distutils. check_lib() was modified to behave
2680 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2681 test for whether installed modules are on sys.path was changed to
2682 use both normcase() and normpath().
2683
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002684- Several minor bugs were fixed in the xml package (the minidom,
2685 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002686
2687- The regression test driver (regrtest.py) behavior when invoked with
2688 -l changed: It now reports a count of objects that are recognized as
2689 garbage but not freed by the garbage collector.
2690
Tim Peters989b7b92000-10-16 20:24:53 +00002691- The regression test for the math module was changed to test
2692 exceptional behavior when the test is run in verbose mode. Python
2693 cannot yet guarantee consistent exception behavior across platforms,
2694 so the exception part of test_math is run only in verbose mode, and
2695 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002696
2697Internals
2698
2699- PyOS_CheckStack() has been disabled on Win64, where it caused
2700 test_sre to fail.
2701
2702Build issues
2703
2704- Changed compiler flags, so that gcc is always invoked with -Wall and
2705 -Wstrict-prototypes. Users compiling Python with GCC should see
2706 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002707 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002708 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002709
Tim Petersa3a3a032000-11-30 05:22:44 +00002710- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002711
2712Tools and other miscellany
2713
2714- The compiler in Tools/compiler was updated to support the new
2715 language features introduced in 2.0: extended print statement, list
2716 comprehensions, and augmented assignments. The new compiler should
2717 also be backwards compatible with Python 1.5.2; the compiler will
2718 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002719 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002720
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002721What's new in 2.0 release candidate 1 (since beta 2)?
2722=====================================================
2723
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002724What is release candidate 1?
2725
2726We believe that release candidate 1 will fix all known bugs that we
2727intend to fix for the 2.0 final release. This release should be a bit
2728more stable than the previous betas. We would like to see even more
2729widespread testing before the final release, so we are producing this
2730release candidate. The final release will be exactly the same unless
2731any show-stopping (or brown bag) bugs are found by testers of the
2732release candidate.
2733
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002734All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002735to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002736
2737Core language, builtins, and interpreter
2738
2739- A bug that caused crashes when __coerce__ was used with augmented
2740 assignment, e.g. +=, was fixed.
2741
2742- Raise ZeroDivisionError when raising zero to a negative number,
2743 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2744 power operator and the result of math.pow(0.0, -2.0) will vary by
2745 platform. On Linux, it raises a ValueError.
2746
2747- A bug in Unicode string interpolation was fixed that occasionally
2748 caused errors with formats including "%%". For example, the
2749 following expression "%% %s" % u"abc" no longer raises a TypeError.
2750
2751- Compilation of deeply nested expressions raises MemoryError instead
2752 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2753
2754- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2755 rendering them useless. They are now written in binary mode again.
2756
2757Standard library
2758
2759- Keyword arguments are now accepted for most pattern and match object
2760 methods in SRE, the standard regular expression engine.
2761
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002762- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002763 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002764
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002765- Several bugs in the Unicode handling and error handling in _tkinter
2766 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002767
2768- Fix memory management errors in Merge() and Tkapp_Call() routines.
2769
2770- Several changes were made to cStringIO to make it compatible with
2771 the file-like object interface and with StringIO. If operations are
2772 performed on a closed object, an exception is raised. The truncate
2773 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002774 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002775
2776- There were many changes made to the linuxaudiodev module and its
2777 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002778 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002779
2780 Note that this module is named poorly, because it should work
2781 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002782 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002783
2784 The module now raises exceptions when errors occur instead of
2785 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2786 audio) and defines a getptr() method that calls the
2787 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2788
2789- The library_version attribute, introduced in an earlier beta, was
2790 removed because it can not be supported with early versions of the C
2791 readline library, which provides no way to determine the version at
2792 compile-time.
2793
2794- The binascii module is now enabled on Win64.
2795
Tim Peters46446d62000-10-09 21:19:31 +00002796- tokenize.py no longer suffers "recursion depth" errors when parsing
2797 programs with very long string literals.
2798
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002799Internals
2800
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002801- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002802 which is called when the interpreter starts up to determine where
2803 the standard library is installed. These vulnerabilities affect all
2804 previous versions of Python and can be exploited by setting very
2805 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2806 setuid Python script, although use of the wrapper in
2807 Misc/setuid-prog.c will eliminate the vulnerability.
2808
2809- Fixed garbage collection bugs in instance creation that were
2810 triggered when errors occurred during initialization. The solution,
2811 applied in cPickle and in PyInstance_New(), is to call
2812 PyObject_GC_Init() after the initialization of the object's
2813 container attributes is complete.
2814
2815- pyexpat adds definitions of PyModule_AddStringConstant and
2816 PyModule_AddObject if the Python version is less than 2.0, which
2817 provides compatibility with PyXML on Python 1.5.2.
2818
2819- If the platform has a bogus definition for LONG_BIT (the number of
2820 bits in a long), an error will be reported at compile time.
2821
2822- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2823 collection crashes and possibly other, unreported crashes.
2824
2825- Fixed a memory leak in _PyUnicode_Fini().
2826
2827Build issues
2828
2829- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002830 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002831 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002832
2833- The mmap.PAGESIZE constant is now initialized using sysconf when
2834 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2835
2836- The md5 file should now compile on all platforms.
2837
2838- The select module now compiles on platforms that do not define
2839 POLLRDNORM and related constants.
2840
2841- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002842 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002843
Jeremy Hylton10921202000-10-09 18:34:12 +00002844- BeOS: A number of changes were made to the build and installation
2845 process. ar-fake now operates on a directory of object files.
2846 dl_export.h is gone, and its macros now appear on the mwcc command
2847 line during build on PPC BeOS.
2848
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002849- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002850 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002851
2852- Cygwin: Support for shared libraries, Tkinter, and sockets.
2853
2854- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2855
2856Tools and other miscellany
2857
2858- Removed debugging prints from main used with freeze.
2859
Tim Peters46446d62000-10-09 21:19:31 +00002860- IDLE auto-indent no longer crashes when it encounters Unicode
2861 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002862
2863What's new in 2.0 beta 2 (since beta 1)?
2864========================================
2865
2866Core language, builtins, and interpreter
2867
Tim Peters482c0212000-09-26 06:33:09 +00002868- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002869 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002870
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002871- Add -h and -V command line options to print the usage message and
2872 Python version number and exit immediately.
2873
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002874- eval() and exec accept Unicode objects as code parameters.
2875
2876- getattr() and setattr() now also accept Unicode objects for the
2877 attribute name, which are converted to strings using the default
2878 encoding before lookup.
2879
2880- Multiplication on string and Unicode now does proper bounds
2881 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2882 string is too long."
2883
2884- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002885 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002886
Jeremy Hylton1b618592000-09-26 05:32:36 +00002887
2888Standard library and extensions
2889
Guido van Rossum5b08f132001-04-16 02:05:23 +00002890- socket module: the OpenSSL code now adds support for RAND_status()
2891 and EGD (Entropy Gathering Device).
2892
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002893- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002894 argument checking; it still takes no arguments.
2895
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002896- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002897
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002898- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002900- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002901
2902- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002903 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002904
2905- copy: Copy Unicode objects atomically.
2906
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002907- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002908
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002909- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002910
Fred Drake67233bc2000-09-26 16:40:27 +00002911- dbm: Add get() and setdefault() methods to dbm object. Add constant
2912 `library' to module that names the library used. Added doc strings
2913 and method names to error messages. Uses configure to determine
2914 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2915 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002916
2917- distutils: Update to version 0.9.3.
2918
2919- dl: Add several dl.RTLD_ constants.
2920
2921- fpectl: Now supported on FreeBSD.
2922
2923- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2924 found by the collector will be saved in gc.garbage. This is useful
2925 for debugging a program that creates reference cycles.
2926
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002927- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002928 of HTTP class. Do not close socket on zero-length response. Do not
2929 crash when server sends invalid content-length header.
2930
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002931- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002932
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002933- marshal: When reading a short, sign-extend on platforms where shorts
2934 are bigger than 16 bits. When reading a long, repair the unportable
2935 sign extension that was being done for 64-bit machines. (It assumed
2936 that signed right shift sign-extends.)
2937
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002938- operator: Add contains(), invert(), __invert__() as aliases for
2939 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002940
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002941- os: Add support for popen2() and popen3() on all platforms where
2942 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002943
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002944- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002945 clicking on a file in Explorer (or passing the file name to the
2946 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002947
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002948- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002949 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002950
2951- pickle: Now raises ValueError when an invalid pickle that contains
2952 a non-string repr where a string repr was expected. This behavior
2953 matches cPickle.
2954
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002955- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002956
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002957- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002958
2959- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002960 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002961 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002962
2963- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002964 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002965
2966- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002967 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002968 few cycles during startup since the first call to
2969 setdefaultencoding() will initialize the codec registry and the
2970 encodings package.
2971
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002972- socket: Support for size hint in readlines() method of object returned
2973 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002974
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002975- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002976 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002977 is followed by whitespace.
2978
Tim Petersa3a3a032000-11-30 05:22:44 +00002979- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002980
2981- struct: Check ranges for bytes and shorts.
2982
2983- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002984 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002985
2986- Tkinter: Image objects are now guaranteed to have unique ids. Set
2987 event.delta to zero if Tk version doesn't support mousewheel.
2988 Removed some debugging prints.
2989
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002990- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002991
Fred Drake67233bc2000-09-26 16:40:27 +00002992- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002993 which works around a bug in Norton AntiVirus 2000 that leads directly
2994 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002995
2996- xml: New version detection code allows PyXML to override standard
2997 XML package if PyXML version is greater than 0.6.1.
2998
Fred Drake64bb3802000-09-26 16:21:35 +00002999- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3000 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3001 tree only for nodes which are sufficiently interesting to a specific
3002 application. Does not provide the HTML-specific extensions. Still
3003 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003004
Fred Drake64bb3802000-09-26 16:21:35 +00003005- xml.sax: SAX 2 support for Python, including all the handler
3006 interfaces needed to process XML 1.0 compliant XML. Some
3007 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003008
Fred Drake64bb3802000-09-26 16:21:35 +00003009- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3010 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003011
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003012
Jeremy Hylton1b618592000-09-26 05:32:36 +00003013C API
3014
3015- Add three new convenience functions for module initialization --
3016 PyModule_AddObject(), PyModule_AddIntConstant(), and
3017 PyModule_AddStringConstant().
3018
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003019- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003020 removed and add #error to Python.h if NULL isn't defined after
3021 #include of stdio.h.
3022
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003023- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024 backwards compatibility (at the source level) with old extensions.
3025
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003026- A wrapper API was added for signal() and sigaction(). Instead of
3027 either function, always use PyOS_getsig() to get a signal handler
3028 and PyOS_setsig() to set one. A new convenience typedef
3029 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003030
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003031- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003032 internal data buffer and size of a string object -- or the default
3033 encoded version of a Unicode object.
3034
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003035- PyString_Size() and PyString_AsString() accept Unicode objects.
3036
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003037- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003038 exists). INT_MAX and LONG_MAX will always be defined, even if
3039 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003040
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003041- PyFloat_FromString takes a second argument, pend, that was
3042 effectively useless. It is now officially useless but preserved for
3043 backwards compatibility. If the pend argument is not NULL, *pend is
3044 set to NULL.
3045
3046- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3047 for the attribute name. See note on getattr() above.
3048
3049- A few bug fixes to argument processing for Unicode.
3050 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3051 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3052 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003053 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003054
3055- Py_BuildValue accepts B format (for bgen-generated code).
3056
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003057
Jeremy Hylton1b618592000-09-26 05:32:36 +00003058Internals
3059
3060- On Unix, fix code for finding Python installation directory so that
3061 it works when argv[0] is a relative path.
3062
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003063- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003064 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003065 rather than by generating a copy of the object.
3066
Tim Peters482c0212000-09-26 06:33:09 +00003067- Several of the internal Unicode tables are much smaller now, and
3068 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003069
Jeremy Hylton97693b02000-09-26 17:42:51 +00003070- In the garbage collector: Fixed bug in collection of tuples. Fixed
3071 bug that caused some instances to be removed from the container set
3072 while they were still live. Fixed parsing in gc.set_debug() for
3073 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003074
3075- Fixed refcount problem in instance deallocation that only occurred
3076 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3077
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003078- On Windows, getpythonregpath is now protected against null data in
3079 registry key.
3080
3081- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003082 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003083
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003084
Jeremy Hylton1b618592000-09-26 05:32:36 +00003085Build and platform-specific issues
3086
3087- Better support of GNU Pth via --with-pth configure option.
3088
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003089- Python/C API now properly exposed to dynamically-loaded extension
3090 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003091
3092- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3093 Don't define MS_SYNC to be zero when it is undefined. Added missing
3094 prototypes in posixmodule.c.
3095
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003096- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003097 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003098
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003099- Fix largefile support on older NetBSD systems and OpenBSD by adding
3100 define for TELL64.
3101
3102
3103Tools and other miscellany
3104
3105- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3106
3107- freeze: The modulefinder now works with 2.0 opcodes.
3108
Tim Petersa3a3a032000-11-30 05:22:44 +00003109- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003110 Move hackery of sys.argv until after the Tk instance has been
3111 created, which allows the application-specific Tkinter
3112 initialization to be executed if present; also pass an explicit
3113 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003114
Jeremy Hylton1b618592000-09-26 05:32:36 +00003115
3116What's new in 2.0 beta 1?
3117=========================
3118
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003119Source Incompatibilities
3120------------------------
3121
3122None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3123such as single-argument append(), connect() and bind(), and changes to
3124str(long) and repr(float).
3125
3126
3127Binary Incompatibilities
3128------------------------
3129
3130- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3131with Python 2.0; these extensions will have to be rebuilt for Python
31322.0.
3133
3134- On Windows, attempting to import a third party extension built for
3135Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3136can do about this. Check your PYTHONPATH environment variable!
3137
3138- Python bytecode files (*.pyc and *.pyo) are not compatible between
3139releases.
3140
3141
3142Overview of Changes Since 1.6
3143-----------------------------
3144
3145There are many new modules (including brand new XML support through
3146the xml package, and i18n support through the gettext module); a list
3147of all new modules is included below. Lots of bugs have been fixed.
3148
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003149The process for making major new changes to the language has changed
3150since Python 1.6. Enhancements must now be documented by a Python
3151Enhancement Proposal (PEP) before they can be accepted.
3152
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003153There are several important syntax enhancements, described in more
3154detail below:
3155
3156 - Augmented assignment, e.g. x += 1
3157
3158 - List comprehensions, e.g. [x**2 for x in range(10)]
3159
3160 - Extended import statement, e.g. import Module as Name
3161
3162 - Extended print statement, e.g. print >> file, "Hello"
3163
3164Other important changes:
3165
3166 - Optional collection of cyclical garbage
3167
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003168Python Enhancement Proposal (PEP)
3169---------------------------------
3170
3171PEP stands for Python Enhancement Proposal. A PEP is a design
3172document providing information to the Python community, or describing
3173a new feature for Python. The PEP should provide a concise technical
3174specification of the feature and a rationale for the feature.
3175
3176We intend PEPs to be the primary mechanisms for proposing new
3177features, for collecting community input on an issue, and for
3178documenting the design decisions that have gone into Python. The PEP
3179author is responsible for building consensus within the community and
3180documenting dissenting opinions.
3181
3182The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003183
3184Augmented Assignment
3185--------------------
3186
3187This must have been the most-requested feature of the past years!
3188Eleven new assignment operators were added:
3189
Guido van Rossume905e952000-09-05 12:42:46 +00003190 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003191
3192For example,
3193
3194 A += B
3195
3196is similar to
3197
3198 A = A + B
3199
3200except that A is evaluated only once (relevant when A is something
3201like dict[index].attr).
3202
3203However, if A is a mutable object, A may be modified in place. Thus,
3204if A is a number or a string, A += B has the same effect as A = A+B
3205(except A is only evaluated once); but if a is a list, A += B has the
3206same effect as A.extend(B)!
3207
3208Classes and built-in object types can override the new operators in
3209order to implement the in-place behavior; the not-in-place behavior is
3210used automatically as a fallback when an object doesn't implement the
3211in-place behavior. For classes, the method name is derived from the
3212method name for the corresponding not-in-place operator by inserting
3213an 'i' in front of the name, e.g. __iadd__ implements in-place
3214__add__.
3215
3216Augmented assignment was implemented by Thomas Wouters.
3217
3218
3219List Comprehensions
3220-------------------
3221
3222This is a flexible new notation for lists whose elements are computed
3223from another list (or lists). The simplest form is:
3224
3225 [<expression> for <variable> in <sequence>]
3226
Guido van Rossum56db0952000-09-06 23:34:25 +00003227For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003228This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003229
3230You can also add a condition:
3231
3232 [<expression> for <variable> in <sequence> if <condition>]
3233
3234For example, [w for w in words if w == w.lower()] would yield the list
3235of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003236than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003237
3238You can also have nested for loops and more than one 'if' clause. For
3239example, here's a function that flattens a sequence of sequences::
3240
3241 def flatten(seq):
3242 return [x for subseq in seq for x in subseq]
3243
3244 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3245
3246This prints
3247
3248 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3249
3250List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003251Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003252
3253
3254Extended Import Statement
3255-------------------------
3256
3257Many people have asked for a way to import a module under a different
3258name. This can be accomplished like this:
3259
3260 import foo
3261 bar = foo
3262 del foo
3263
3264but this common idiom gets old quickly. A simple extension of the
3265import statement now allows this to be written as follows:
3266
3267 import foo as bar
3268
3269There's also a variant for 'from ... import':
3270
3271 from foo import bar as spam
3272
3273This also works with packages; e.g. you can write this:
3274
3275 import test.regrtest as regrtest
3276
3277Note that 'as' is not a new keyword -- it is recognized only in this
3278context (this is only possible because the syntax for the import
3279statement doesn't involve expressions).
3280
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003281Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003282
3283
3284Extended Print Statement
3285------------------------
3286
3287Easily the most controversial new feature, this extension to the print
3288statement adds an option to make the output go to a different file
3289than the default sys.stdout.
3290
3291For example, to write an error message to sys.stderr, you can now
3292write:
3293
3294 print >> sys.stderr, "Error: bad dog!"
3295
3296As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003297evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003298
3299 print >> None, "Hello world"
3300
3301is equivalent to
3302
3303 print "Hello world"
3304
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003305Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003306
3307
3308Optional Collection of Cyclical Garbage
3309---------------------------------------
3310
3311Python is now equipped with a garbage collector that can hunt down
3312cyclical references between Python objects. It's no replacement for
3313reference counting; in fact, it depends on the reference counts being
3314correct, and decides that a set of objects belong to a cycle if all
3315their reference counts can be accounted for from their references to
3316each other. This devious scheme was first proposed by Eric Tiedemann,
3317and brought to implementation by Neil Schemenauer.
3318
3319There's a module "gc" that lets you control some parameters of the
3320garbage collection. There's also an option to the configure script
3321that lets you enable or disable the garbage collection. In 2.0b1,
3322it's on by default, so that we (hopefully) can collect decent user
3323experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003324performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003325off by default in the final 2.0 release.
3326
3327
3328Smaller Changes
3329---------------
3330
3331A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3332map(None, seq1, seq2, ...) when the sequences have the same length;
3333i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3334the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003335zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003336
3337sys.version_info is a tuple (major, minor, micro, level, serial).
3338
3339Dictionaries have an odd new method, setdefault(key, default).
3340dict.setdefault(key, default) returns dict[key] if it exists; if not,
3341it sets dict[key] to default and returns that value. Thus:
3342
3343 dict.setdefault(key, []).append(item)
3344
3345does the same work as this common idiom:
3346
3347 if not dict.has_key(key):
3348 dict[key] = []
3349 dict[key].append(item)
3350
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003351There are two new variants of SyntaxError that are raised for
3352indentation-related errors: IndentationError and TabError.
3353
3354Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3355escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003356
3357The limits on the size of expressions and file in Python source code
3358have been raised from 2**16 to 2**32. Previous versions of Python
3359were limited because the maximum argument size the Python VM accepted
3360was 2**16. This limited the size of object constructor expressions,
3361e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3362limit was raised thanks to a patch by Charles Waldman that effectively
3363fixes the problem. It is now much more likely that you will be
3364limited by available memory than by an arbitrary limit in Python.
3365
3366The interpreter's maximum recursion depth can be modified by Python
3367programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3368limit is the maximum number of recursive calls that can be made by
3369Python code. The limit exists to prevent infinite recursion from
3370overflowing the C stack and causing a core dump. The default value is
33711000. The maximum safe value for a particular platform can be found
3372by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003373
3374New Modules and Packages
3375------------------------
3376
3377atexit - for registering functions to be called when Python exits.
3378
3379imputil - Greg Stein's alternative API for writing custom import
3380hooks.
3381
3382pyexpat - an interface to the Expat XML parser, contributed by Paul
3383Prescod.
3384
3385xml - a new package with XML support code organized (so far) in three
3386subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3387would fill a volume. There's a special feature whereby a
3388user-installed package named _xmlplus overrides the standard
3389xmlpackage; this is intended to give the XML SIG a hook to distribute
3390backwards-compatible updates to the standard xml package.
3391
3392webbrowser - a platform-independent API to launch a web browser.
3393
3394
Guido van Rossume905e952000-09-05 12:42:46 +00003395Changed Modules
3396---------------
3397
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003398array -- new methods for array objects: count, extend, index, pop, and
3399remove
3400
3401binascii -- new functions b2a_hex and a2b_hex that convert between
3402binary data and its hex representation
3403
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003404calendar -- Many new functions that support features including control
3405over which day of the week is the first day, returning strings instead
3406of printing them. Also new symbolic constants for days of week,
3407e.g. MONDAY, ..., SUNDAY.
3408
3409cgi -- FieldStorage objects have a getvalue method that works like a
3410dictionary's get method and returns the value attribute of the object.
3411
3412ConfigParser -- The parser object has new methods has_option,
3413remove_section, remove_option, set, and write. They allow the module
3414to be used for writing config files as well as reading them.
3415
3416ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003417optionally support the RFC 959 REST command.
3418
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003419gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003420
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003421httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3422the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003423
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003424locale -- implement getdefaultlocale for Win32 and Macintosh
3425
3426marshal -- no longer dumps core when marshaling deeply nested or
3427recursive data structures
3428
3429os -- new functions isatty, seteuid, setegid, setreuid, setregid
3430
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003431os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3432support under Unix.
3433
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003434os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003435
3436os.path -- fix semantics of os.path.commonprefix
3437
3438smtplib -- support for sending very long messages
3439
3440socket -- new function getfqdn()
3441
3442readline -- new functions to read, write and truncate history files.
3443The readline section of the library reference manual contains an
3444example.
3445
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003446select -- add interface to poll system call
3447
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003448shutil -- new copyfileobj function
3449
3450SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3451HTTP server.
3452
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003453Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003454
3455urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003456e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003457
3458whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003459
3460
3461Obsolete Modules
3462----------------
3463
3464None. However note that 1.6 made a whole slew of modules obsolete:
3465stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3466poly, zmod, strop, util, whatsound.
3467
3468
3469Changed, New, Obsolete Tools
3470----------------------------
3471
Tim Peters8b092332000-09-05 20:15:25 +00003472None.
Guido van Rossume905e952000-09-05 12:42:46 +00003473
3474
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003475C-level Changes
3476---------------
3477
3478Several cleanup jobs were carried out throughout the source code.
3479
3480All C code was converted to ANSI C; we got rid of all uses of the
3481Py_PROTO() macro, which makes the header files a lot more readable.
3482
3483Most of the portability hacks were moved to a new header file,
3484pyport.h; several other new header files were added and some old
3485header files were removed, in an attempt to create a more rational set
3486of header files. (Few of these ever need to be included explicitly;
3487they are all included by Python.h.)
3488
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003489Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003490and Win64, especially for the new Intel Itanium processor. Mick also
3491added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003492
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003493The C APIs to return an object's size have been update to consistently
3494use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3495previous versions, the abstract interfaces used PyXXX_Length and the
3496concrete interfaces used PyXXX_Size. The old names,
3497e.g. PyObject_Length, are still available for backwards compatibility
3498at the API level, but are deprecated.
3499
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003500The PyOS_CheckStack function has been implemented on Windows by
3501Fredrik Lundh. It prevents Python from failing with a stack overflow
3502on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003503
3504The GC changes resulted in creation of two new slots on object,
3505tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003506the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003507
3508The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003509C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003510
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003511PyErr_Format has been updated to automatically calculate the size of
3512the buffer needed to hold the formatted result string. This change
3513prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003514
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003515New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003516
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003517PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3518that are the same as their non-Ex counterparts except they take an
3519extra flag argument that tells them to close the file when done.
3520
3521XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003522
Tim Peters8b092332000-09-05 20:15:25 +00003523
3524Windows Changes
3525---------------
3526
3527New popen2/popen3/peopen4 in os module (see Changed Modules above).
3528
3529os.popen is much more usable on Windows 95 and 98. See Microsoft
3530Knowledge Base article Q150956. The Win9x workaround described there
3531is implemented by the new w9xpopen.exe helper in the root of your
3532Python installation. Note that Python uses this internally; it is not
3533a standalone program.
3534
3535Administrator privileges are no longer required to install Python
3536on Windows NT or Windows 2000. If you have administrator privileges,
3537Python's registry info will be written under HKEY_LOCAL_MACHINE.
3538Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003539under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003540uses of Python, but will prevent some advanced uses from working
3541(for example, running a Python script as an NT service, or possibly
3542from CGI).
3543
3544[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3545installer; instead, it installs the needed Tcl/Tk files directly in the
3546Python directory. If you already have a Tcl/Tk installation, this
3547wastes some disk space (about 4 Megs) but avoids problems with
3548conflicting Tcl/Tk installations, and makes it much easier for Python
3549to ensure that Tcl/Tk can find all its files.
3550
3551[This was new in 1.6] The Windows installer now installs by default in
3552\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3553
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003554
3555Updates to the changes between 1.5.2 and 1.6
3556--------------------------------------------
3557
3558The 1.6 NEWS file can't be changed after the release is done, so here
3559is some late-breaking news:
3560
3561New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3562and changes to getlocale() and setlocale().
3563
3564The new module is now enabled per default.
3565
3566It is not true that the encodings codecs cannot be used for normal
3567strings: the string.encode() (which is also present on 8-bit strings
3568!) allows using them for 8-bit strings too, e.g. to convert files from
3569cp1252 (Windows) to latin-1 or vice-versa.
3570
3571Japanese codecs are available from Tamito KAJIYAMA:
3572http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3573
3574
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003575======================================================================