blob: 486c562ef48ab342c9942e4f12993233ba9ab636 [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
Walter Dörwald3430d702002-06-17 10:43:59 +00009- Unicode objects in sys.path are no longer ignored but treated
10 as directory names.
11
Guido van Rossum9562bcf2002-06-14 21:31:18 +000012- The built-ins slice() and buffer() are now callable types. The
13 types classobj (formerly class), code, function, instance, and
14 instancemethod (formerly instance-method), which have no built-in
15 names but are accessible through the types module, are now also
16 callable. The type dict-proxy is renamed to dictproxy.
17
Neal Norwitz1f68fc72002-06-14 00:50:42 +000018- Fixed string.startswith and string.endswith builtin methods
19 so they accept negative indices. [SF bug 493951]
20
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000021- Fixed a bug with a continue inside a try block and a yield in the
22 finally clause. [SF bug 567538]
23
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000024- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000025 with a third "stride" parameter. For example, "hello world"[::-1]
26 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000027
Guido van Rossum9f7549b2002-06-10 21:39:42 +000028- Cycles going through the __class__ link of a new-style instance are
29 now detected by the garbage collector.
30
Guido van Rossum9923ffe2002-06-04 19:52:53 +000031- Classes using __slots__ are now properly garbage collected.
32 [SF bug 519621]
33
34- Tightened the __slots__ rules: a slot name must be a valid Python
35 identifier.
36
Guido van Rossum2e4e0262002-06-04 05:58:34 +000037- The constructor for the module type now requires a name argument and
38 takes an optional docstring argument. Previously, this constructor
39 ignored its arguments. As a consequence, deriving a class from a
40 module (not from the module type) is now illegal; previously this
41 created an unnamed module, just like invoking the module type did.
42 [SF bug 563060]
43
Neal Norwitzd68f5172002-05-29 15:54:55 +000044- A new warning PendingDeprecationWarning was added to provide
45 direction on features which are in the process of being deprecated.
46 The warning will not be printed by default. To see the pending
47 deprecations, use -Walways::PendingDeprecationWarning::
48 as a command line option or warnings.filterwarnings() in code.
49
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000050- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000051 for 'str' and 'unicode', and can be used instead of
52 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000053 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000054 is an abstract base class and cannot be instantiated directly.
55
Fred Draked0ba6362002-05-02 21:28:26 +000056- Deprecated features of xrange objects have been removed as
57 promised. The start, stop, and step attributes and the tolist()
58 method no longer exist. xrange repetition and slicing have been
59 removed.
60
Guido van Rossum7dab2422002-04-26 19:40:56 +000061- New builtin function enumerate(x), from PEP 279. Example:
62 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
63 The argument can be an arbitrary iterable object.
64
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000065- The assert statement no longer tests __debug__ at runtime. This means
66 that assert statements cannot be disabled by assigning a false value
67 to __debug__.
68
Walter Dörwald068325e2002-04-15 13:36:47 +000069- A method zfill() was added to str and unicode, that fills a numeric
70 string to the left with zeros. For example,
71 "+123".zfill(6) -> "+00123".
72
Guido van Rossum862fe3c2002-04-15 12:36:47 +000073- Complex numbers supported divmod() and the // and % operators, but
74 these make no sense. Since this was documented, they're being
75 deprecated now.
76
Guido van Rossum26dd8302002-04-26 20:11:29 +000077- String and unicode methods lstrip(), rstrip() and strip() now take
78 an optional argument that specifies the characters to strip. For
79 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000080
Guido van Rossumc69343b2002-04-12 19:22:48 +000081- Added a new dict method pop(key). This removes and returns the
82 value corresponding to key. [SF patch #539949]
83
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000084- Changed new-style class instantiation so that when C's __new__
85 method returns something that's not a C instance, its __init__ is
86 not called. [SF bug #537450]
87
Guido van Rossum181e41a2002-04-06 00:23:25 +000088- Fixed super() to work correctly with class methods. [SF bug #535444]
89
Guido van Rossum47834462002-04-04 15:21:33 +000090- A new built-in type, bool, has been added, as well as built-in
91 names for its two values, True and False. Comparisons and sundry
92 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000093 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000094 is backward compatible.
95
Guido van Rossum95b62a62002-03-29 01:07:24 +000096- Fixed two bugs reported as SF #535905: under certain conditions,
97 deallocating a deeply nested structure could cause a segfault in the
98 garbage collector, due to interaction with the "trashcan" code;
99 access to the current frame during destruction of a local variable
100 could access a pointer to freed memory.
101
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000102- The optional object allocator has been enabled by default.
103
Guido van Rossum8c842552002-03-14 23:05:54 +0000104- If you try to pickle an instance of a class that has __slots__ but
105 doesn't define or override __getstate__, a TypeError is now raised.
106 This is done by adding a bozo __getstate__ to the class that always
107 raises TypeError. (Before, this would appear to be pickled, but the
108 state of the slots would be lost.)
109
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000110- PyErr_Display will provide file and line information for all exceptions
111 that have an attribute print_file_and_line, not just SyntaxErrors.
112
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000113- The UTF-8 codec will now encode and decode Unicode surrogates
114 correctly and without raising exceptions for unpaired ones.
115
Neal Norwitz649b7592002-01-01 19:07:13 +0000116- file.xreadlines() now raises a ValueError if the file is closed:
117 Previously, an xreadlines object was returned which would raise
118 a ValueError when the xreadlines.next() method was called.
119
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000120- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000121 An exception will now be raised if more than one argument is used.
122
Tim Petersaf8446f2001-12-21 21:36:50 +0000123Extension modules
124
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000125- The 'new' module is no longer an extension, but a Python module that
126 only exists for backwards compatibility. Its contents are no longer
127 functions but callable type objects.
128
Tim Peters81b92512002-04-29 01:37:32 +0000129- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000130 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000131 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000132
Martin v. Löwis606edc12002-06-13 21:09:11 +0000133- posix.killpg, posix.mknod, and posix.getpgid have been added where
134 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000135
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000136- The locale module now exposes the C library's gettext interface.
137
Tim Petersfbf74f22002-03-14 19:06:01 +0000138- A security hole ("double free") was found in zlib-1.1.3, a popular
139 third party compression library used by some Python modules. The
140 hole was quickly plugged in zlib-1.1.4, and the Windows build of
141 Python now ships with zlib-1.1.4.
142
Martin v. Löwis688357e2002-04-08 21:28:20 +0000143- pwd, grp, and resource return enhanced tuples now, with symbolic
144 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000145
Martin v. Löwis99866332002-03-01 10:27:01 +0000146- array.array is now a type object. A new format character
147 'u' indicates Py_UNICODE arrays. For those, .tounicode and
148 .fromunicode methods are available. Arrays now support __iadd__
149 and __imul__.
150
Neal Norwitze790eae2002-01-01 21:14:12 +0000151- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000152 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
153 is called.
154
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000155- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
156 been added where available.
157
Tim Petersaf8446f2001-12-21 21:36:50 +0000158Library
159
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000160- Some fixes in the copy module: when an object is copied through its
161 __reduce__ method, there was no check for a __setstate__ method on
162 the result [SF patch 565085]; deepcopy should treat instances of
163 custom metaclasses the same way it treats instances of type 'type'
164 [SF patch 560794].
165
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000166- Sockets now support timeout mode. After s.settimeout(T), where T is
167 a float expressing seconds, subsequent operations raise an exception
168 if they cannot be completed within T seconds. To disable timeout
169 mode, use s.settimeout(None).
170
171- getopt.gnu_getopt was added. This supports GNU-style option
172 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000173
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000174- Stop using strings for exceptions. String objects used for
175 exceptions are now classes deriving from Exception. The objects
176 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
177 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000178
Walter Dörwald474458d2002-06-04 15:16:29 +0000179- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
180 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
181 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
182 big endian systems were added to the codecs module. The old names
183 BOM32_* and BOM64_* were off by a factor of 2.
184
Guido van Rossumf9257822002-06-18 20:43:18 +0000185- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000186
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000187- ftplib.retrlines() now tests for callback is None rather than testing
188 for False. Was causing an error when given a callback object which
189 was callable but also returned len() as zero. The change may
190 create new breakage if the caller relied on the undocumented behavior
191 and called with callback set to [] or some other False value not
192 identical to None.
193
Tim Peters46c04e12002-05-05 20:40:00 +0000194- random.gauss() uses a piece of hidden state used by nothing else,
195 and the .seed() and .whseed() methods failed to reset it. In other
196 words, setting the seed didn't completely determine the sequence of
197 results produced by random.gauss(). It does now. Programs repeatedly
198 mixing calls to a seed method with calls to gauss() may see different
199 results now.
200
Fred Drake7f781c92002-05-01 20:33:53 +0000201- The pickle.Pickler class grew a clear_memo() method to mimic that
202 provided by cPickle.Pickler.
203
Tim Peters81b92512002-04-29 01:37:32 +0000204- difflib's SequenceMatcher class now does a dynamic analysis of
205 which elements are so frequent as to constitute noise. For
206 comparing files as sequences of lines, this generally works better
207 than the IS_LINE_JUNK function, and function ndiff's linejunk
208 argument defaults to None now as a result. A happy benefit is
209 that SequenceMatcher may run much faster now when applied
210 to large files with many duplicate lines (for example, C program
211 text with lots of repeated "}" and "return NULL;" lines).
212
Guido van Rossum256705b2002-04-23 13:29:43 +0000213- New Text.dump() method in Tkinter module.
214
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000215- New distutils commands for building packagers were added to
216 support pkgtool on Solaris and swinstall on HP-UX.
217
218- distutils now has a new abstract binary packager base class
219 command/bdist_packager, which simplifies writing packagers.
220 This will hopefully provide the missing bits to encourage
221 people to submit more packagers, e.g. for Debian, FreeBSD
222 and other systems.
223
Guido van Rossumf9257822002-06-18 20:43:18 +0000224- The UTF-16, -LE and -BE stream readers now raise a
225 NotImplementedError for all calls to .readline(). Previously, they
226 used to just produce garbage or fail with an encoding error --
227 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 +0000228 work well with these.
229
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000230- compileall now supports quiet operation.
231
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000232- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000233 connections.
234
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000235- socket module: the SSL support was broken out of the main
236 _socket module C helper and placed into a new _ssl helper
237 which now gets imported by socket.py if available and working.
238
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000239- encodings package: added aliases for all supported IANA character
240 sets
241
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000242- ftplib: to safeguard the user's privacy, anonymous login will use
243 "anonymous@" as default password, rather than the real user and host
244 name.
245
Fred Drake36736122002-01-10 13:50:31 +0000246- webbrowser: tightened up the command passed to os.system() so that
247 arbitrary shell code can't be executed because a bogus URL was
248 passed in.
249
Tim Peters11bd9942002-02-01 00:52:29 +0000250- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000251 gettext.find an optional all argument. Translations will now fallback
252 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000253
Martin v. Löwis9668b932002-01-12 11:27:42 +0000254- distutils bdist commands now offer a --skip-build option.
255
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000256- warnings.warn now accepts a Warning instance as first argument.
257
Fred Drakefed7e852002-04-04 19:36:15 +0000258- The xml.sax.expatreader.ExpatParser class will no longer create
259 circular references by using itself as the locator that gets passed
260 to the content handler implementation. [SF bug #535474]
261
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000262- The email.Parser.Parser class now properly parses strings regardless
263 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
264 or CRLF). Also, the Header class's constructor default arguments
265 has changed slightly so that an explicit maxlinelen value is always
266 honored.
267
Tim Petersaf8446f2001-12-21 21:36:50 +0000268Tools/Demos
269
Marc-André Lemburg46260092002-04-04 16:17:11 +0000270- freeze.py now produces binaries which can import shared modules,
271 unlike before when this failed due to missing symbol exports in
272 the generated binary.
273
Tim Petersaf8446f2001-12-21 21:36:50 +0000274Build
275
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000276- The configure option --without-doc-strings can be used to remove the
277 doc strings from the builtin functions and modules; this reduces the
278 size of the executable.
279
Tim Peters639295f2002-04-21 07:30:30 +0000280- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
281 say how or when to configure it, or how to turn it off.
282
Martin v. Löwis1142de32002-03-29 16:28:31 +0000283- On Unix, a shared libpython2.3.so can be created with --enable-shared.
284
Tim Peters8deda702002-03-30 10:06:07 +0000285- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
286 preprocessor symbols were eliminated. The internal decisions they
287 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000288
Fred Drake7d28b732002-05-02 21:17:00 +0000289- The tools used to build the documentation now work under Cygwin as
290 well as Unix.
291
Skip Montanaro57454e52002-06-14 20:30:31 +0000292- The bsddb and dbm module builds have been changed to try and avoid version
293 skew problems and disable linkage with Berkeley DB 1.85 unless the
294 installer knows what s/he's doing. See the section on building these
295 modules in the README file for details.
296
Tim Petersaf8446f2001-12-21 21:36:50 +0000297C API
298
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000299- Added new macro PySequence_ITEM(o, i) that directly calls
300 sq_item without rechecking that o is a sequence and without
301 adjusting for negative indices.
302
Fred Draked0ba6362002-05-02 21:28:26 +0000303- PyRange_New() now raises ValueError if the fourth argument is not 1.
304 This is part of the removal of deprecated features of the xrange
305 object.
306
Guido van Rossum517c7d42002-04-26 02:49:14 +0000307- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
308 coercion if both arguments have the same type but this type has the
309 CHECKTYPES flag set. This is to better support proxies.
310
Neil Schemenauer9344b142002-04-12 23:00:08 +0000311- The type of tp_free has been changed from "void (*)(PyObject *)" to
312 "void (*)(void *)".
313
314- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
315
Guido van Rossum0986d822002-04-08 01:38:42 +0000316- A type can now inherit its metatype from its base type. Previously,
317 when PyType_Ready() was called, if ob_type was found to be NULL, it
318 was always set to &PyType_Type; now it is set to base->ob_type,
319 where base is tp_base, defaulting to &PyObject_Type.
320
321- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
322
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000323- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000324
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000325- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000326 without going through the buffer API.
327
Martin v. Löwis7198a522002-01-01 19:59:11 +0000328- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
329
Tim Peters10a3bb52001-12-25 19:07:38 +0000330- An old #define of ANY as void has been removed from pyport.h. This
331 hasn't been used since Python's pre-ANSI days, and the #define has
332 been marked as obsolete since then. SF bug 495548 says it created
333 conflicts with other packages, so keeping it around wasn't harmless.
334
Tim Petersaf8446f2001-12-21 21:36:50 +0000335- Because Python's magic number scheme broke on January 1st, we decided
336 to stop Python development. Thanks for all the fish!
337
Tim Petersfb05db22002-03-11 00:24:00 +0000338- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000339 scheme to a new one. See Python/import.c for details.
340
Tim Petersaf8446f2001-12-21 21:36:50 +0000341New platforms
342
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000343- AtheOS is now supported.
344
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000345- GNU/Hurd is now supported.
346
Tim Petersaf8446f2001-12-21 21:36:50 +0000347Tests
348
349Windows
350
Tim Peters08e72952002-04-16 20:48:01 +0000351- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
352 of that has been fixed in the installer (disabled Wise's "delete in-
353 use files" uninstall option).
354
Guido van Rossum181e41a2002-04-06 00:23:25 +0000355- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
356
Tim Peters33187922002-04-04 20:02:04 +0000357- The installer now installs Start menu shortcuts under (the local
358 equivalent of) "All Users" when doing an Admin install.
359
Tim Petersfb05db22002-03-11 00:24:00 +0000360- file.truncate([newsize]) now works on Windows for all newsize values.
361 It used to fail if newsize didn't fit in 32 bits, reflecting a
362 limitation of MS _chsize (which is no longer used).
363
Tim Petersab034fa2002-02-01 11:27:43 +0000364- os.waitpid() is now implemented for Windows, and can be used to block
365 until a specified process exits. This is similar to, but not exactly
366 the same as, os.waitpid() on POSIX systems. If you're waiting for
367 a specific process whose pid was obtained from one of the spawn()
368 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000369 See the docs for details. The docs were changed to clarify that
370 spawn functions return, and waitpid requires, a process handle on
371 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000372
Tim Peters11bd9942002-02-01 00:52:29 +0000373- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000374 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000375 to a nasty problem: before 2.3, if you got a temp file on Windows, it
376 got wrapped in an object whose close() method first closed the
377 underlying file, then deleted the file. This usually worked fine.
378 However, the spawn family of functions on Windows create (at a low C
379 level) the same set of open files in the spawned process Q as were
380 open in the spawning process P. If a temp file f was among them, then
381 doing f.close() in P first closed P's C-level file handle on f, but Q's
382 C-level file handle on f remained open, so the attempt in P to delete f
383 blew up with a "Permission denied" error (Windows doesn't allow
384 deleting open files). This was surprising, subtle, and difficult to
385 work around.
386
387- The os module now exports all the symbolic constants usable with the
388 low-level os.open() on Windows: the new constants in 2.3 are
389 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
390 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
391 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
392 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
393 (so specify both if you want both; note that neither is useful unless
394 specified with O_CREAT too).
395
Tim Petersaf8446f2001-12-21 21:36:50 +0000396Mac
397
398
Tim Peters909c0912001-12-14 23:16:18 +0000399What's New in Python 2.2 final?
400Release date: 21-Dec-2001
401===============================
402
403Type/class unification and new-style classes
404
Barry Warsaw52acb492001-12-21 20:04:22 +0000405- pickle.py, cPickle: allow pickling instances of new-style classes
406 with a custom metaclass.
407
Tim Peters909c0912001-12-14 23:16:18 +0000408Core and builtins
409
Barry Warsaw52acb492001-12-21 20:04:22 +0000410- weakref proxy object: when comparing, unwrap both arguments if both
411 are proxies.
412
Tim Peters909c0912001-12-14 23:16:18 +0000413Extension modules
414
Barry Warsaw52acb492001-12-21 20:04:22 +0000415- binascii.b2a_base64(): fix a potential buffer overrun when encoding
416 very short strings.
417
418- cPickle: the obscure "fast" mode was suspected of causing stack
419 overflows on the Mac. Hopefully fixed this by setting the recursion
420 limit much smaller. If the limit is too low (it only affects
421 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
422 when compiling cPickle.c (or in pyconfig.h).
423
Tim Peters909c0912001-12-14 23:16:18 +0000424Library
425
Barry Warsaw52acb492001-12-21 20:04:22 +0000426- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
427 close or delete time).
428
429- rfc822.py: fixed a bug where the address '<>' was converted to None
430 instead of an empty string (also fixes the email.Utils module).
431
432- xmlrpclib.py: version 1.0.0; uses precision for doubles.
433
434- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000435 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000436
Tim Peters909c0912001-12-14 23:16:18 +0000437Tools/Demos
438
439Build
440
441C API
442
443New platforms
444
445Tests
446
447Windows
448
Barry Warsaw52acb492001-12-21 20:04:22 +0000449- distutils package: fixed broken Windows installers (bdist_wininst).
450
451- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
452 instances are deleted at process exit time.
453
454- socket.py: prevent mysterious warnings when socket instances are
455 deleted at process exit time.
456
457- posixmodule.c: fix a Windows crash with stat() of a filename ending
458 in backslash.
459
Tim Peters909c0912001-12-14 23:16:18 +0000460Mac
461
Barry Warsaw52acb492001-12-21 20:04:22 +0000462- The Carbon toolbox modules have been upgraded to Universal Headers
463 3.4, and experimental CoreGraphics and CarbonEvents modules have
464 been added. All only for framework-enabled MacOSX.
465
Tim Peters909c0912001-12-14 23:16:18 +0000466
Tim Peters6272dfd2001-12-13 19:34:00 +0000467What's New in Python 2.2c1?
468Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000469===========================
470
471Type/class unification and new-style classes
472
Barry Warsaw06557452001-12-14 20:47:12 +0000473- Guido's tutorial introduction to the new type/class features has
474 been extensively updated. See
475
476 http://www.python.org/2.2/descrintro.html
477
478 That remains the primary documentation in this area.
479
Guido van Rossum33bab012001-12-05 22:45:48 +0000480- Fixed a leak: instance variables declared with __slots__ were never
481 deleted!
482
Guido van Rossum4b800852001-12-03 00:54:52 +0000483- The "delete attribute" method of descriptor objects is called
484 __delete__, not __del__. In previous releases, it was mistakenly
485 called __del__, which created an unfortunate overloading condition
486 with finalizers. (The "get attribute" and "set attribute" methods
487 are still called __get__ and __set__, respectively.)
488
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000489- Some subtle issues with the super built-in were fixed:
490
491 (a) When super itself is subclassed, its __get__ method would still
492 return an instance of the base class (i.e., of super).
493
494 (b) super(C, C()).__class__ would return C rather than super. This
495 is confusing. To fix this, I decided to change the semantics of
496 super so that it only applies to code attributes, not to data
497 attributes. After all, overriding data attributes is not
498 supported anyway.
499
500 (c) The __get__ method didn't check whether the argument was an
501 instance of the type used in creation of the super instance.
502
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000503- Previously, hash() of an instance of a subclass of a mutable type
504 (list or dictionary) would return some value, rather than raising
505 TypeError. This has been fixed. Also, directly calling
506 dict.__hash__ and list.__hash__ now raises the same TypeError
507 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000508
Guido van Rossumd331cb52001-12-05 19:46:42 +0000509- New-style objects now support deleting their __dict__. This is for
510 all intents and purposes equivalent to assigning a brand new empty
511 dictionary, but saves space if the object is not used further.
512
Tim Petersb3c9af12001-11-17 00:21:57 +0000513Core and builtins
514
Tim Peters3caca232001-12-06 06:23:26 +0000515- -Qnew now works as documented in PEP 238: when -Qnew is passed on
516 the command line, all occurrences of "/" use true division instead
517 of classic division. See the PEP for details. Note that "all"
518 means all instances in library and 3rd-party modules, as well as in
519 your own code. As the PEP says, -Qnew is intended for use only in
520 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000521 Note that test_coercion.py in the standard Python test suite fails
522 under -Qnew; this is expected, and won't be repaired until true
523 division becomes the default (in the meantime, test_coercion is
524 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000525
Fred Drake6c01e252001-12-14 17:08:12 +0000526- complex() now only allows the first argument to be a string
527 argument, and raises TypeError if either the second arg is a string
528 or if the second arg is specified when the first is a string.
529
Tim Petersb3c9af12001-11-17 00:21:57 +0000530Extension modules
531
Martin v. Löwis560da622001-11-24 09:24:51 +0000532- gc.get_referents was renamed to gc.get_referrers.
533
Tim Petersb3c9af12001-11-17 00:21:57 +0000534Library
535
Tim Peters25059d32001-12-07 20:35:43 +0000536- Functions in the os.spawn() family now release the global interpreter
537 lock around calling the platform spawn. They should always have done
538 this, but did not before 2.2c1. Multithreaded programs calling
539 an os.spawn function with P_WAIT will no longer block all Python threads
540 until the spawned program completes. It's possible that some programs
541 relies on blocking, although more likely by accident than by design.
542
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000543- webbrowser defaults to netscape.exe on OS/2 now.
544
Martin v. Löwis652e1912001-11-25 14:50:56 +0000545- Tix.ResizeHandle exposes detach_widget, hide, and show.
546
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000547- The charset alias windows_1252 has been added.
548
Barry Warsaw06557452001-12-14 20:47:12 +0000549- types.StringTypes is a tuple containing the defined string types;
550 usually this will be (str, unicode), but if Python was compiled
551 without Unicode support it will be just (str,).
552
553- The pulldom and minidom modules were synchronized to PyXML.
554
Tim Petersb3c9af12001-11-17 00:21:57 +0000555Tools/Demos
556
Barry Warsaw06557452001-12-14 20:47:12 +0000557- A new script called Tools/scripts/google.py was added, which fires
558 off a search on Google.
559
Tim Petersb3c9af12001-11-17 00:21:57 +0000560Build
561
Barry Warsaw06557452001-12-14 20:47:12 +0000562- Note that release builds of Python should arrange to define the
563 preprocessor symbol NDEBUG on the command line (or equivalent).
564 In the 2.2 pre-release series we tried to define this by magic in
565 Python.h instead, but it proved to cause problems for extension
566 authors. The Unix, Windows and Mac builds now all define NDEBUG in
567 release builds via cmdline (or equivalent) instead. Ports to
568 other platforms should do likewise.
569
Jack Jansen1999ef42001-12-06 21:47:20 +0000570- It is no longer necessary to use --with-suffix when building on a
571 case-insensitive file system (such as Mac OS X HFS+). In the build
572 directory an extension is used, but not in the installed python.
573
Tim Petersb3c9af12001-11-17 00:21:57 +0000574C API
575
Tim Petersf582b822001-12-11 18:51:08 +0000576- New function PyDict_MergeFromSeq2() exposes the builtin dict
577 constructor's logic for updating a dictionary from an iterable object
578 producing key-value pairs.
579
Tim Peterscffed4b2001-11-29 03:26:37 +0000580- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000581 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000582 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
583 dump core in some bad cases. This has been repaired. As a result,
584 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
585 previously went unchallenged.
586
Tim Petersb3c9af12001-11-17 00:21:57 +0000587New platforms
588
589Tests
590
591Windows
592
593Mac
594
Jack Jansenffa260f2001-12-06 21:14:00 +0000595- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
596 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000597
Barry Warsaw06557452001-12-14 20:47:12 +0000598- Changed logic for finding python home in Mac OS X framework Pythons.
599 Now sys.executable points to the executable again, in stead of to
600 the shared library. The latter is used only for locating the python
601 home.
602
603
Tim Peters84362bc2001-10-19 17:55:30 +0000604What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000605Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000606===========================
607
608Type/class unification and new-style classes
609
Guido van Rossum3d27df02001-11-15 20:27:54 +0000610- Multiple inheritance mixing new-style and classic classes in the
611 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000612
613 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000614 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000615
616 The MRO (method resolution order) for each base class is respected
617 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000618 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000619 This needs to be documented.
620
Tim Petersa427a2b2001-10-29 22:25:45 +0000621- The new builtin dictionary() constructor, and dictionary type, have
622 been renamed to dict. This reflects a decade of common usage.
623
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000624- dict() now accepts an iterable object producing 2-sequences. For
625 example, dict(d.items()) == d for any dictionary d. The argument,
626 and the elements of the argument, can be any iterable objects.
627
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000628- New-style classes can now have a __del__ method, which is called
629 when the instance is deleted (just like for classic classes).
630
Guido van Rossum12d955c2001-10-26 14:56:06 +0000631- Assignment to object.__dict__ is now possible, for objects that are
632 instances of new-style classes that have a __dict__ (unless the base
633 class forbids it).
634
Guido van Rossumc8e56452001-10-22 00:43:43 +0000635- Methods of built-in types now properly check for keyword arguments
636 (formerly these were silently ignored). The only built-in methods
637 that take keyword arguments are __call__, __init__ and __new__.
638
Guido van Rossum86443212001-10-27 22:28:54 +0000639- The socket function has been converted to a type; see below.
640
Tim Peters84362bc2001-10-19 17:55:30 +0000641Core and builtins
642
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000643- Assignment to __debug__ raises SyntaxError at compile-time. This
644 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000645 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000646
Guido van Rossum12d955c2001-10-26 14:56:06 +0000647- Clarified the error messages for unsupported operands to an operator
648 (like 1 + '').
649
Tim Peters84362bc2001-10-19 17:55:30 +0000650Extension modules
651
Tim Peters5ebfd362001-11-13 23:11:19 +0000652- mmap has a new keyword argument, "access", allowing a uniform way for
653 both Windows and Unix users to create read-only, write-through and
654 copy-on-write memory mappings. This was previously possible only on
655 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000656 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000657 platforms. Thanks to Jay T Miller for repairing this!
658
Tim Peters169ded02001-11-03 19:57:21 +0000659- By default, the gc.garbage list now contains only those instances in
660 unreachable cycles that have __del__ methods; in 2.1 it contained all
661 instances in unreachable cycles. "Instances" here has been generalized
662 to include instances of both new-style and old-style classes.
663
Guido van Rossum12d955c2001-10-26 14:56:06 +0000664- The socket module defines a new method for socket objects,
665 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000666 send() until all data has been sent. Also, the socket function has
667 been converted to a subclassable type, like list and tuple (etc.)
668 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000669
670- Various bugfixes to the curses module. There is now a test suite
671 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000672
Guido van Rossum692adf12001-10-30 03:03:03 +0000673- binascii.b2a_base64 no longer places an arbitrary restriction of 57
674 bytes on its input.
675
Tim Peters84362bc2001-10-19 17:55:30 +0000676Library
677
Tim Peters5ebfd362001-11-13 23:11:19 +0000678- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000679 convenience function.
680
Tim Peters75335872001-11-03 19:35:43 +0000681- Symbolic group names in regular expressions must be unique. For
682 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
683 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000684 Python 2.2 detects this error at regexp compilation time;
685 previously, the error went undetected, and results were
686 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
687 pattern.subn() methods have been rewritten in C. Also, an
688 experimental function/method finditer() has been added, which works
689 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000690
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000691- Tix exposes more commands through the classes DirSelectBox,
692 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
693 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
694 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
695
Tim Peters98791af2001-10-23 01:59:54 +0000696- Traceback objects are now scanned by cyclic garbage collection, so
697 cycles created by casual use of sys.exc_info() no longer cause
698 permanent memory leaks (provided garbage collection is enabled).
699
Guido van Rossum49192142001-10-24 20:51:44 +0000700- os.extsep -- a new variable needed by the RISCOS support. It is the
701 separator used by extensions, and is '.' on all platforms except
702 RISCOS, where it is '/'. There is no need to use this variable
703 unless you have a masochistic desire to port your code to RISCOS.
704
Barry Warsaw012852b2001-11-16 16:17:27 +0000705- mimetypes.py has optional support for non-standard, but commonly
706 found types. guess_type() and guess_extension() now accept an
707 optional `strict' flag, defaulting to true, which controls whether
708 recognize non-standard types or not. A few non-standard types we
709 know about have been added. Also, when run as a script, there are
710 new -l and -e options.
711
712- statcache is now deprecated.
713
714- email.Utils.formatdate() now produces the preferred RFC 2822 style
715 dates with numeric timezones (it used to produce obsolete dates
716 hard coded to "GMT" timezone). An optional `localtime' flag is
717 added to produce dates in the local timezone, with daylight savings
718 time properly taken into account.
719
720- In pickle and cPickle, instead of masking errors in load() by
721 transforming them into SystemError, we let the original exception
722 propagate out. Also, implement support for __safe_for_unpickling__
723 in pickle, as it already was supported in cPickle.
724
Tim Peters84362bc2001-10-19 17:55:30 +0000725Tools/Demos
726
727Build
728
Barry Warsaw012852b2001-11-16 16:17:27 +0000729- The dbm module is built using libdb1 if available. The bsddb module
730 is built with libdb3 if available.
731
732- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
733
Tim Peters84362bc2001-10-19 17:55:30 +0000734C API
735
Tim Peters1fc240e2001-10-26 05:06:50 +0000736- New function PySequence_Fast_GET_SIZE() returns the size of a non-
737 NULL result from PySequence_Fast(), more quickly than calling
738 PySequence_Size().
739
Barry Warsaw012852b2001-11-16 16:17:27 +0000740- New argument unpacking function PyArg_UnpackTuple() added.
741
742- New functions PyObject_CallFunctionObjArgs() and
743 PyObject_CallMethodObjArgs() have been added to make it more
744 convenient and efficient to call functions and methods from C.
745
746- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
747 possible that this will propagate errors it didn't before.
748
749- New function PyObject_CheckReadBuffer(), which returns true if its
750 argument supports the single-segment readable buffer interface.
751
Tim Peters84362bc2001-10-19 17:55:30 +0000752New platforms
753
Guido van Rossum86443212001-10-27 22:28:54 +0000754- We've finally confirmed that this release builds on HP-UX 11.00,
755 *with* threads, and passes the test suite.
756
Tim Peters7a33d8b2001-11-05 02:51:07 +0000757- Thanks to a series of patches from Michael Muller, Python may build
758 again under OS/2 Visual Age C++.
759
Guido van Rossum49192142001-10-24 20:51:44 +0000760- Updated RISCOS port by Dietmar Schwertberger.
761
Tim Peters84362bc2001-10-19 17:55:30 +0000762Tests
763
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000764- Added a test script for the curses module. It isn't run automatically;
765 regrtest.py must be run with '-u curses' to enable it.
766
Tim Peters84362bc2001-10-19 17:55:30 +0000767Windows
768
Barry Warsaw012852b2001-11-16 16:17:27 +0000769Mac
770
771- PythonScript has been moved to unsupported and is slated to be
772 removed completely in the next release.
773
774- It should now be possible to build applets that work on both OS9 and
775 OSX.
776
777- The core is now linked with CoreServices not Carbon; as a side
778 result, default 8bit encoding on OSX is now ASCII.
779
780- Python should now build on OSX 10.1.1
781
Tim Peters84362bc2001-10-19 17:55:30 +0000782
Tim Petersabf925f2001-09-28 21:53:42 +0000783What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000784Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000785===========================
786
787Type/class unification and new-style classes
788
Guido van Rossum687ae002001-10-15 22:03:32 +0000789- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000790 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000791 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000792 remains: the __dict__ of a new-style class is a read-only proxy; you
793 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000794 __defined__ attribute of new-style types no longer exists, for lack
795 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000796 future a __cache__ may be resurrected with a similar function, if I
797 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000798
Tim Peters1c9ca872001-10-04 06:43:12 +0000799- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
800 always returned None, even when there was a class docstring).
801
802- doctest now finds and runs docstrings attached to new-style classes,
803 class methods, static methods, and properties.
804
Guido van Rossum9074ef62001-10-16 21:34:49 +0000805Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000806
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000807- A very subtle syntactical pitfall in list comprehensions was fixed.
808 For example: [a+b for a in 'abc', for b in 'def']. The comma in
809 this example is a mistake. Previously, this would silently let 'a'
810 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
811 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
812 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
813 Note that [a for a in <singleton>] is a convoluted way to say
814 [<singleton>] anyway, so it's not like any expressiveness is lost.
815
Guido van Rossum9074ef62001-10-16 21:34:49 +0000816- getattr(obj, name, default) now only catches AttributeError, as
817 documented, rather than returning the default value for all
818 exceptions (which could mask bugs in a __getattr__ hook, for
819 example).
820
Fred Drakecb7a6b52001-10-22 18:41:51 +0000821- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000822 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000823 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000824 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000825
Guido van Rossum1c486092001-10-19 02:05:35 +0000826- unicode(obj) now behaves more like str(obj), accepting arbitrary
827 objects, and calling a __unicode__ method if it exists.
828 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000829 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000830
Barry Warsawf6fb1712001-10-19 05:35:40 +0000831- isinstance() now allows any object as the first argument and a
832 class, a type or something with a __bases__ tuple attribute for the
833 second argument. The second argument may also be a tuple of a
834 class, type, or something with __bases__, in which case isinstance()
835 will return true if the first argument is an instance of any of the
836 things contained in the second argument tuple. E.g.
837
838 isinstance(x, (A, B))
839
840 returns true if x is an instance of A or B.
841
Guido van Rossum9074ef62001-10-16 21:34:49 +0000842Extension modules
843
844- thread.start_new_thread() now returns the thread ID (previously None).
845
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000846- binascii has now two quopri support functions, a2b_qp and b2a_qp.
847
Guido van Rossumc524d952001-10-19 01:31:59 +0000848- readline now supports setting the startup_hook and the
849 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000850
Guido van Rossumc524d952001-10-19 01:31:59 +0000851- os and posix supports chroot(), setgroups() and unsetenv() where
852 available. The stat(), fstat(), statvfs() and fstatvfs() functions
853 now return "pseudo-sequences" -- the various fields can now be
854 accessed as attributes (e.g. os.stat("/").st_mtime) but for
855 backwards compatibility they also behave as a fixed-length sequence.
856 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000857 attributes.
858
859- time: localtime(), gmtime() and strptime() now return a
860 pseudo-sequence similar to the os.stat() return value, with
861 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000862
Guido van Rossum9074ef62001-10-16 21:34:49 +0000863- Decompression objects in the zlib module now accept an optional
864 second parameter to decompress() that specifies the maximum amount
865 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000866
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000867- optional SSL support in the socket module now exports OpenSSL
868 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
869 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000870 automatically seed its PRNG. Also, the keyfile and certfile
871 arguments to socket.ssl() are now optional.
872
873- posixmodule (and by extension, the os module on POSIX platforms) now
874 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000875
Guido van Rossum9074ef62001-10-16 21:34:49 +0000876Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000877
Tim Peters7402f792001-10-02 03:53:41 +0000878- doctest now excludes functions and classes not defined by the module
879 being tested, thanks to Tim Hochberg.
880
Fred Drakecb7a6b52001-10-22 18:41:51 +0000881- HotShot, a new profiler implemented using a C-based callback, has
882 been added. This substantially reduces the overhead of profiling,
883 but it is still quite preliminary. Support modules and
884 documentation will be added in upcoming releases (before 2.2 final).
885
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000886- profile now produces correct output in situations where an exception
887 raised in Python is cleared by C code (e.g. hasattr()). This used
888 to cause wrong output, including spurious claims of recursive
889 functions and attribution of time spent to the wrong function.
890
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000891 The code and documentation for the derived OldProfile and HotProfile
892 profiling classes was removed. The code hasn't worked for years (if
893 you tried to use them, they raised exceptions). OldProfile
894 intended to reproduce the behavior of the profiler Python used more
895 than 7 years ago, and isn't interesting anymore. HotProfile intended
896 to provide a faster profiler (but producing less information), and
897 that's a worthy goal we intend to meet via a different approach (but
898 without losing information).
899
Tim Peterscce092d2001-10-09 05:31:56 +0000900- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000901 a much better system-specific calibration constant. The constant can
902 now be specified in an instance constructor, or as a Profile class or
903 instance variable, instead of by editing profile.py's source code.
904 Calibration must still be done manually (see the docs for the profile
905 module).
906
907 Note that Profile.calibrate() must be overriden by subclasses.
908 Improving the accuracy required exploiting detailed knowledge of
909 profiler internals; the earlier method abstracted away the details
910 and measured a simplified model instead, but consequently computed
911 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000912
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000913- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000914 which indicates whether output is intended for the header 'Q'
915 encoding.
916
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000917- The SocketServer.ThreadingMixIn class now closes the request after
918 finish_request() returns. (Not when it errors out though.)
919
Barry Warsawf6fb1712001-10-19 05:35:40 +0000920- The nntplib module's NNTP.body() method has grown a `file' argument
921 to allow saving the message body to a file.
922
923- The email package has added a class email.Parser.HeaderParser which
924 only parses headers and does not recurse into the message's body.
925 Also, the module/class MIMEAudio has been added for representing
926 audio data (contributed by Anthony Baxter).
927
928- ftplib should be able to handle files > 2GB.
929
930- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
931 ON, and OFF.
932
Fred Drakecb7a6b52001-10-22 18:41:51 +0000933- xml.dom.minidom NodeList objects now support the length attribute
934 and item() method as required by the DOM specifications.
935
Guido van Rossumed554f62001-10-02 23:15:37 +0000936Tools/Demos
937
938- Demo/dns was removed. It no longer serves any purpose; a package
939 derived from it is now maintained by Anthony Baxter, see
940 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000941
Barry Warsawf6fb1712001-10-19 05:35:40 +0000942- The freeze tool has been made more robust, and two new options have
943 been added: -X and -E.
944
Tim Petersabf925f2001-09-28 21:53:42 +0000945Build
946
Barry Warsawf6fb1712001-10-19 05:35:40 +0000947- configure will use CXX in LINKCC if CXX is used to build main() and
948 the system requires to link a C++ main using the C++ compiler.
949
Tim Petersabf925f2001-09-28 21:53:42 +0000950C API
951
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000952- The documentation for the tp_compare slot is updated to require that
953 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
954 not correct. This is not yet enforced but will be enforced in
955 Python 2.3; even later, we may use -2 to indicate errors and +2 for
956 "NotImplemented". Right now, -1 should be used for an error return.
957
Tim Petersd38b1c72001-09-30 05:09:37 +0000958- PyLong_AsLongLong() now accepts int (as well as long) arguments.
959 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
960 as long) arguments.
961
Guido van Rossum3c288632001-10-16 21:13:49 +0000962- PyThread_start_new_thread() now returns a long int giving the thread
963 ID, if one can be calculated; it returns -1 for error, 0 if no
964 thread ID is calculated (this is an incompatible change, but only
965 the thread module used this API). This code has only really been
966 tested on Linux and Windows; other platforms please beware (and
967 report any bugs or strange behavior).
968
Guido van Rossum1c486092001-10-19 02:05:35 +0000969- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
970 input.
971
Tim Petersabf925f2001-09-28 21:53:42 +0000972New platforms
973
974Tests
975
976Windows
977
Tim Peters04cf1d32001-10-09 22:39:40 +0000978- Installer: If you install IDLE, and don't disable file-extension
979 registration, a new "Edit with IDLE" context (right-click) menu entry
980 is created for .py and .pyw files.
981
Tim Peters1ce3cf72001-10-01 17:58:40 +0000982- The signal module now supports SIGBREAK on Windows, thanks to Steven
983 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
984 action remains to call Win32 ExitProcess(). This can be changed via
985 signal.signal(). For example:
986
987 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
988 # (SIGINT) behavior.
989 import signal
990 signal.signal(signal.SIGBREAK,
991 signal.default_int_handler)
992
993 try:
994 while 1:
995 pass
996 except KeyboardInterrupt:
997 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
998 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
999 # program without the possibility for any Python-level cleanup).
1000 print "Clean exit"
1001
Tim Petersabf925f2001-09-28 21:53:42 +00001002
Tim Petersb07352e2001-09-08 01:25:47 +00001003What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001004Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001005===========================
1006
Guido van Rossum808eea72001-09-25 04:15:41 +00001007Type/class unification and new-style classes
1008
1009- pydoc and inspect are now aware of new-style classes;
1010 e.g. help(list) at the interactive prompt now shows proper
1011 documentation for all operations on list objects.
1012
1013- Applications using Jim Fulton's ExtensionClass module can now safely
1014 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1015 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1016 examples also work again. It is hoped that Gtk and Boost also work
1017 with 2.2a4 and beyond. (If you can confirm this, please write
1018 webmaster@python.org; if there are still problems, please open a bug
1019 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001020
Tim Peters66c1a522001-09-24 21:17:50 +00001021- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001022 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001023 in the constructed property object. fget, fset and fdel weren't
1024 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1025 associate a docstring with a property.
1026
Guido van Rossum808eea72001-09-25 04:15:41 +00001027- Comparison overloading is now more completely implemented. For
1028 example, a str subclass instance can properly be compared to a str
1029 instance, and it can properly overload comparison. Ditto for most
1030 other built-in object types.
1031
1032- The repr() of new-style classes has changed; instead of <type
1033 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1034 *except* for built-in types, which are still rendered as <type
1035 'Foo'> (to avoid upsetting existing code that might parse or
1036 otherwise rely on repr() of certain type objects).
1037
1038- The repr() of new-style objects is now always <Foo object at XXX>;
1039 previously, it was sometimes <Foo instance at XXX>.
1040
1041- For new-style classes, what was previously called __getattr__ is now
1042 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001043 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001044 one in classic classes is defined which is called only if regular
1045 attribute access raises AttributeError; to catch *all* attribute
1046 access, you can use __getattribute__ (for new-style classes). If
1047 both are defined, __getattribute__ is called first, and if it raises
1048 AttributeError, __getattr__ is called.
1049
1050- The __class__ attribute of new-style objects can be assigned to.
1051 The new class must have the same C-level object layout as the old
1052 class.
1053
1054- The builtin file type can be subclassed now. In the usual pattern,
1055 "file" is the name of the builtin type, and file() is a new builtin
1056 constructor, with the same signature as the builtin open() function.
1057 file() is now the preferred way to open a file.
1058
1059- Previously, __new__ would only see sequential arguments passed to
1060 the type in a constructor call; __init__ would see both sequential
1061 and keyword arguments. This made no sense whatsoever any more, so
1062 now both __new__ and __init__ see all arguments.
1063
1064- Previously, hash() applied to an instance of a subclass of str or
1065 unicode always returned 0. This has been repaired.
1066
1067- Previously, an operation on an instance of a subclass of an
1068 immutable type (int, long, float, complex, tuple, str, unicode),
1069 where the subtype didn't override the operation (and so the
1070 operation was handled by the builtin type), could return that
1071 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001072 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001073 with the same value as s.
1074
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001075- Provisional support for pickling new-style objects has been added.
1076
Guido van Rossum808eea72001-09-25 04:15:41 +00001077Core
1078
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001079- file.writelines() now accepts any iterable object producing strings.
1080
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001081- PyUnicode_FromEncodedObject() now works very much like
1082 PyObject_Str(obj) in that it tries to use __str__/tp_str
1083 on the object if the object is not a string or buffer. This
1084 makes unicode() behave like str() when applied to non-string/buffer
1085 objects.
1086
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001087- PyFile_WriteObject now passes Unicode objects to the file's write
1088 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001089 of a print statement must support Unicode objects, i.e. they must
1090 at least convert them into ASCII strings.
1091
Guido van Rossum624c8af2001-09-18 15:21:04 +00001092- Thread scheduling on Solaris should be improved; it is no longer
1093 necessary to insert a small sleep at the start of a thread in order
1094 to let other runnable threads be scheduled.
1095
Tim Petersb07352e2001-09-08 01:25:47 +00001096Library
1097
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001098- StringIO.StringIO instances and cStringIO.StringIO instances support
1099 read character buffer compatible objects for their .write() methods.
1100 These objects are converted to strings and then handled as such
1101 by the instances.
1102
Barry Warsaw2f600732001-09-24 04:28:10 +00001103- The "email" package has been added. This is basically a port of the
1104 mimelib package <http://sf.net/projects/mimelib> with API changes
1105 and some implementations updated to use iterators and generators.
1106
Tim Peters8a9c2842001-09-22 21:30:22 +00001107- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1108 restores the ability of Tools/scripts/ndiff.py to start producing output
1109 before the entire comparison is complete.
1110
Barry Warsaw58b072d2001-09-22 04:44:21 +00001111- StringIO.StringIO instances and cStringIO.StringIO instances support
1112 iteration just like file objects (i.e. their .readline() method is
1113 called for each iteration until it returns an empty string).
1114
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001115- The codecs module has grown four new helper APIs to access
1116 builtin codecs: getencoder(), getdecoder(), getreader(),
1117 getwriter().
1118
Guido van Rossum624c8af2001-09-18 15:21:04 +00001119- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1120 simplifies writing XML RPC servers.
1121
Barry Warsaw647d5e82001-09-28 17:01:02 +00001122- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001123 after interpretation of symbolic links. On non-Unix systems, this
1124 is an alias for os.path.abspath().
1125
Tim Peters16a77ad2001-09-08 04:00:12 +00001126- operator.indexOf() (PySequence_Index() in the C API) now works with any
1127 iterable object.
1128
Guido van Rossum624c8af2001-09-18 15:21:04 +00001129- smtplib now supports various authentication and security features of
1130 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001131
Guido van Rossum624c8af2001-09-18 15:21:04 +00001132- hmac: a new module implementing keyed hashing for message
1133 authentication.
1134
1135- mimetypes now recognizes more extensions and file types. At the
1136 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001137
Guido van Rossum624c8af2001-09-18 15:21:04 +00001138- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001139 Python 2.2 bytecode generation. It has also been promoted from a
1140 Tool to a standard library package. (Tools/compiler still exists as
1141 a sample driver.)
1142
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001143Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001144
Tim Petersb07352e2001-09-08 01:25:47 +00001145Build
1146
Guido van Rossum624c8af2001-09-18 15:21:04 +00001147- Large file support (LFS) is now automatic when the platform supports
1148 it; no more manual configuration tweaks are needed. On Linux, at
1149 least, it's possible to have a system whose C library supports large
1150 files but whose kernel doesn't; in this case, large file support is
1151 still enabled but doesn't do you any good unless you upgrade your
1152 kernel or share your Python executable with another system whose
1153 kernel has large file support.
1154
1155- The configure script now supplies plausible defaults in a
1156 cross-compilation environment. This doesn't mean that the supplied
1157 values are always correct, or that cross-compilation now works
1158 flawlessly -- but it's a first step (and it shuts up most of
1159 autoconf's warnings about AC_TRY_RUN).
1160
1161- The Unix build is now a bit less chatty, courtesy of the parser
1162 generator. The build is completely silent (except for errors) when
1163 using "make -s", thanks to a -q option to setup.py.
1164
Tim Petersb07352e2001-09-08 01:25:47 +00001165C API
1166
Guido van Rossum624c8af2001-09-18 15:21:04 +00001167- The "structmember" API now supports some new flag bits to deny read
1168 and/or write access to attributes in restricted execution mode.
1169
Tim Petersb07352e2001-09-08 01:25:47 +00001170New platforms
1171
Guido van Rossum624c8af2001-09-18 15:21:04 +00001172- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1173 (http://familiar.handhelds.org).
1174
Tim Petersb07352e2001-09-08 01:25:47 +00001175Tests
1176
Tim Peters8a9c2842001-09-22 21:30:22 +00001177- The "classic" standard tests, which work by comparing stdout to
1178 an expected-output file under Lib/test/output/, no longer stop at
1179 the first mismatch. Instead the test is run to completion, and a
1180 variant of ndiff-style comparison is used to report all differences.
1181 This is much easier to understand than the previous style of reporting.
1182
1183- The unittest-based standard tests now use regrtest's test_main()
1184 convention, instead of running as a side-effect of merely being
1185 imported. This allows these tests to be run in more natural and
1186 flexible ways as unittests, outside the regrtest framework.
1187
1188- regrtest.py is much better integrated with unittest and doctest now,
1189 especially in regard to reporting errors.
1190
Tim Petersb07352e2001-09-08 01:25:47 +00001191Windows
1192
Guido van Rossum624c8af2001-09-18 15:21:04 +00001193- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001194 that support it (NTFS under Windows 2000). See "What's New in
1195 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001196
Tim Petersb07352e2001-09-08 01:25:47 +00001197
Tim Petersedc99312001-08-22 21:36:50 +00001198What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001199Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001200===========================
1201
1202Core
1203
Tim Peters9fffa3e2001-09-04 05:14:19 +00001204- Conversion of long to float now raises OverflowError if the long is too
1205 big to represent as a C double.
1206
Tim Peters32f453e2001-09-03 08:35:41 +00001207- The 3-argument builtin pow() no longer allows a third non-None argument
1208 if either of the first two arguments is a float, or if both are of
1209 integer types and the second argument is negative (in which latter case
1210 the arguments are converted to float, so this is really the same
1211 restriction).
1212
Tim Peters5d2b77c2001-09-03 05:47:38 +00001213- The builtin dir() now returns more information, and sometimes much
1214 more, generally naming all attributes of an object, and all attributes
1215 reachable from the object via its class, and from its class's base
1216 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1217 an empty list. In 2.2a3,
1218
1219 >>> dir([])
1220 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1221 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1222 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1223 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1224 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1225 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1226 'reverse', 'sort']
1227
1228 dir(module) continues to return only the module's attributes, though.
1229
Tim Petersbdee63f2001-09-02 03:40:59 +00001230- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001231 than raising OverflowError. This is a partial implementation of PEP
1232 237. You can use -Wdefault::OverflowWarning to enable a warning for
1233 this situation, and -Werror::OverflowWarning to revert to the old
1234 OverflowError exception.
1235
Guido van Rossum61c345f2001-09-04 03:26:15 +00001236- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001237 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001238 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1239 -Qold, meaning the / operator has its classic meaning and no
1240 warnings are issued. Using -Qwarn issues a run-time warning about
1241 all uses of classic division for int and long arguments; -Qwarnall
1242 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001243 (for use with fixdiv.py).
1244 [Note: the remainder of this paragraph (preserved below) became
1245 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1246 <obsolete>
1247 Using -Qnew is questionable; it turns on new division by default, but
1248 only in the __main__ module. You can usefully combine -Qwarn or
1249 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1250 warns about classic division everywhere else.
1251 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001252
Tim Petersbdee63f2001-09-02 03:40:59 +00001253- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001254 long, float, str, unicode, and tuple. (The types complex, list and
1255 dictionary can also be subclassed; this was introduced earlier.)
1256 Note that restrictions apply when subclassing immutable built-in
1257 types: you can only affect the value of the instance by overloading
1258 __new__. You can add mutable attributes, and the subclass instances
1259 will have a __dict__ attribute, but you cannot change the "value"
1260 (as implemented by the base class) of an immutable subclass instance
1261 once it is created.
1262
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001263- The dictionary constructor now takes an optional argument, a
1264 mapping-like object, and initializes the dictionary from its
1265 (key, value) pairs.
1266
Tim Petersbdee63f2001-09-02 03:40:59 +00001267- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001268 "cooperative super calls" in a multiple inheritance setting. For an
1269 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1270
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001271- A new built-in type, property, has been added. This enables the
1272 creation of "properties". These are attributes implemented by
1273 getter and setter functions (or only one of these for read-only or
1274 write-only attributes), without the need to override __getattr__.
1275 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001276
Tim Petersbdee63f2001-09-02 03:40:59 +00001277- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001278 liberalized, to allow leading zeroes. Examples of literals now
1279 legal that were SyntaxErrors before:
1280
1281 00.0 0e3 0100j 07.5 00000000000000000008.
1282
Tim Petersbdee63f2001-09-02 03:40:59 +00001283- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001284 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1285
Tim Petersedc99312001-08-22 21:36:50 +00001286Library
1287
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001288- telnetlib includes symbolic names for the options, and support for
1289 setting an option negotiation callback.
1290
Tim Petersa40c7932001-09-05 22:36:56 +00001291- The new C standard no longer requires that math libraries set errno to
1292 ERANGE on overflow. For platform libraries that exploit this new
1293 freedom, Python's overflow-checking was wholly broken. A new overflow-
1294 checking scheme attempts to repair that, but may not be reliable on all
1295 platforms (C doesn't seem to provide anything both useful and portable
1296 in this area anymore).
1297
Martin v. Löwis44f86962001-09-05 13:44:54 +00001298- Asynchronous timeout actions are available through the new class
1299 threading.Timer.
1300
Tim Peters78526162001-09-05 00:53:45 +00001301- math.log and math.log10 now return sensible results for even huge
1302 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1303
Tim Petersbdee63f2001-09-02 03:40:59 +00001304- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001305 currently held. See the docs for the imp module.
1306
Tim Petersbdee63f2001-09-02 03:40:59 +00001307- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001308 dumps containing ints written on platforms where Python ints are 8 bytes.
1309 When read on a box where Python ints are 4 bytes, such values are
1310 converted to Python longs.
1311
Tim Petersbdee63f2001-09-02 03:40:59 +00001312- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001313 code objects is no longer allowed. This plugs a security hole.
1314
Steve Purcell6091cd62001-09-06 16:05:17 +00001315- unittest.TestResult instances no longer store references to tracebacks
1316 generated by test failures. This prevents unexpected dangling references
1317 to objects that should be garbage collected between tests.
1318
Tim Petersedc99312001-08-22 21:36:50 +00001319Tools
1320
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001321- Tools/scripts/fixdiv.py has been added which can be used to fix
1322 division operators as per PEP 238.
1323
Tim Petersedc99312001-08-22 21:36:50 +00001324Build
1325
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001326- If you are an adventurous person using Mac OS X you may want to look at
1327 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1328 application, which can be used for experimenting with Carbon or Cocoa.
1329 Discussion of this on pythonmac-sig, please.
1330
Tim Peters7eea37e2001-09-04 22:08:56 +00001331C API
1332
1333- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001334
Tim Peters9fffa3e2001-09-04 05:14:19 +00001335- Note that PyLong_AsDouble can fail! This has always been true, but no
1336 callers checked for it. It's more likely to fail now, because overflow
1337 errors are properly detected now. The proper way to check:
1338
1339 double x = PyLong_AsDouble(some_long_object);
1340 if (x == -1.0 && PyErr_Occurred()) {
1341 /* The conversion failed. */
1342 }
1343
Tim Petersbdee63f2001-09-02 03:40:59 +00001344- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001345 compile but will not participate in GC. To upgrade an extension
1346 module:
1347
1348 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001349
Neil Schemenauer4042c692001-08-30 15:38:01 +00001350 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1351 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001352
Neil Schemenauer4042c692001-08-30 15:38:01 +00001353 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1354 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001355
Neil Schemenauer4042c692001-08-30 15:38:01 +00001356 - remove PyGC_HEAD_SIZE from object size calculations
1357
1358 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1359
Tim Petersbdee63f2001-09-02 03:40:59 +00001360- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001361 These can be used safely to construct string objects from a
1362 sprintf-style format string (similar to the format string supported
1363 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001364
Tim Petersedc99312001-08-22 21:36:50 +00001365New platforms
1366
Tim Petersb7da0902001-09-02 23:01:43 +00001367- Stephen Hansen contributed patches sufficient to get a clean compile
1368 under Borland C (Windows), but he reports problems running it and ran
1369 out of time to complete the port. Volunteers? Expect a MemoryError
1370 when importing the types module; this is probably shallow, and
1371 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001372
Tim Petersedc99312001-08-22 21:36:50 +00001373Tests
1374
1375Windows
1376
Tim Peters6e13a562001-09-06 00:32:15 +00001377- Large file support is now enabled on Win32 platforms as well as on
1378 Win64. This means that, for example, you can use f.tell() and f.seek()
1379 to manipulate files larger than 2 gigabytes (provided you have enough
1380 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001381 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1382 filesize limit, and large file support makes no difference there.
1383 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1384 NTFS has no practical limit on file size, and files of any size can be
1385 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001386
Tim Petersbdee63f2001-09-02 03:40:59 +00001387- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001388 points to command.com (patch from Brian Quinlan).
1389
Tim Petersedc99312001-08-22 21:36:50 +00001390
Tim Peters20f51a72001-07-21 02:31:40 +00001391What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001392Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001393===========================
1394
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001395Build
1396
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001397- Tim Peters developed a brand new Windows installer using Wise 8.1,
1398 generously donated to us by Wise Solutions.
1399
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001400- configure supports a new option --enable-unicode, with the values
1401 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1402 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001403
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001404- A new configure option --enable-framework builds a Mac OS X framework,
1405 which "make frameworkinstall" will install. This provides a starting
1406 point for more mac-like functionality, join pythonmac-sig@python.org
1407 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001408
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001409- The NeXT platform is no longer supported.
1410
1411- The `new' module is now statically linked.
1412
Tim Peters0afb6092001-08-15 06:06:44 +00001413Tools
1414
1415- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001416 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001417 the module docstring for details.
1418
Tim Peters20f51a72001-07-21 02:31:40 +00001419Tests
1420
Tim Peters5e824c32001-08-12 22:25:01 +00001421- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001422 platforms, allowing to give clearer test result output. regrtest
1423 also has optional --use/-u switch to run normally disabled tests
1424 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001425
Tim Peters20f51a72001-07-21 02:31:40 +00001426- Several new tests in the standard test suite, with special thanks to
1427 Nick Mathewson.
1428
1429Core
1430
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001431- The floor division operator // has been added as outlined in PEP
1432 238. The / operator still provides classic division (and will until
1433 Python 3.0) unless "from __future__ import division" is included, in
1434 which case the / operator will provide true division. The operator
1435 module provides truediv() and floordiv() functions. Augmented
1436 assignment variants are included, as are the equivalent overloadable
1437 methods and C API methods. See the PEP for a full discussion:
1438 <http://python.sf.net/peps/pep-0238.html>
1439
Tim Peters6cd6a822001-08-17 22:11:27 +00001440- Future statements are now effective in simulated interactive shells
1441 (like IDLE). This should "just work" by magic, but read Michael
1442 Hudson's "Future statements in simulated shells" PEP 264 for full
1443 details: <http://python.sf.net/peps/pep-0264.html>.
1444
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001445- The type/class unification (PEP 252-253) was integrated into the
1446 trunk and is not so tentative any more (the exact specification of
1447 some features is still tentative). A lot of work has done on fixing
1448 bugs and adding robustness and features (performance still has to
1449 come a long way).
1450
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001451- Warnings about a mismatch in the Python API during extension import
1452 now use the Python warning framework (which makes it possible to
1453 write filters for these warnings).
1454
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001455- A function's __dict__ (aka func_dict) will now always be a
1456 dictionary. It used to be possible to delete it or set it to None,
1457 but now both actions raise TypeErrors. It is still legal to set it
1458 to a dictionary object. Getting func.__dict__ before any attributes
1459 have been assigned now returns an empty dictionary instead of None.
1460
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001461- A new command line option, -E, was added which disables the use of
1462 all environment variables, or at least those that are specifically
1463 significant to Python. Usually those have a name starting with
1464 "PYTHON". This was used to fix a problem where the tests fail if
1465 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1466 older distribution.
1467
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001468Library
1469
Tim Peters5e824c32001-08-12 22:25:01 +00001470- New class Differ and new functions ndiff() and restore() in difflib.py.
1471 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001472 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001473
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001474- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1475 value using the minimal quoting required for the value; more
1476 reliable than using xml.sax.saxutils.escape() for attribute values.
1477
1478- Readline completion support for cmd.Cmd was added.
1479
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001480- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1481
1482- Added function threading.BoundedSemaphore()
1483
1484- Added Ka-Ping Yee's cgitb.py module.
1485
1486- The `new' module now exposes the CO_xxx flags.
1487
Martin v. Löwis560da622001-11-24 09:24:51 +00001488- The gc module offers the get_referents function.
1489
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001490New platforms
1491
1492C API
1493
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001494- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1495 which provide a cross-platform implementations for the
1496 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1497 the standard sprintf() and vsprintf() C lib APIs, these versions
1498 apply bounds checking on the used buffer which enhances protection
1499 against buffer overruns.
1500
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001501- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001502 and extensions using different Unicode widths is rendered next to
1503 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001504 will result in an ImportError. Unicode extensions writers must make
1505 sure to check the Unicode width compatibility in their extensions by
1506 using at least one of the mangled Unicode APIs in the extension.
1507
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001508- Two new flags METH_NOARGS and METH_O are available in method definition
1509 tables to simplify implementation of methods with no arguments and a
1510 single untyped argument. Calling such methods is more efficient than
1511 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1512 deprecated.
1513
Tim Petersc1731372001-08-04 08:12:36 +00001514Windows
1515
1516- "import module" now compiles module.pyw if it exists and nothing else
1517 relevant is found.
1518
Tim Peters20f51a72001-07-21 02:31:40 +00001519
Guido van Rossum55a78992001-07-17 17:22:32 +00001520What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001521Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001522===========================
1523
1524Core
Tim Petersa814db52001-05-14 07:05:58 +00001525
Tim Peters6d6c1a32001-08-02 04:15:00 +00001526- TENTATIVELY, a large amount of code implementing much of what's
1527 described in PEP 252 (Making Types Look More Like Classes) and PEP
1528 253 (Subtyping Built-in Types) was added. This will be released
1529 with Python 2.2a1. Documentation will be provided separately
1530 through http://www.python.org/2.2/. The purpose of releasing this
1531 with Python 2.2a1 is to test backwards compatibility. It is
1532 possible, though not likely, that a decision is made not to release
1533 this code as part of 2.2 final, if any serious backwards
1534 incompapatibilities are found during alpha testing that cannot be
1535 repaired.
1536
Guido van Rossum55a78992001-07-17 17:22:32 +00001537- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001538 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001539 more 'yield' statements. See PEP 255. Since this adds a new
1540 keyword to the language, this feature must be enabled by including a
1541 future statement: "from __future__ import generators" (see PEP 236).
1542 Generators will become a standard feature in a future release
1543 (probably 2.3). Without this future statement, 'yield' remains an
1544 ordinary identifier, but a warning is issued each time it is used.
1545 (These warnings currently don't conform to the warnings framework of
1546 PEP 230; we intend to fix this in 2.2a2.)
1547
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001548- The UTF-16 codec was modified to be more RFC compliant. It will now
1549 only remove BOM characters at the start of the string and then
1550 only if running in native mode (UTF-16-LE and -BE won't remove a
1551 leading BMO character).
1552
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001553- Strings now have a new method .decode() to complement the already
1554 existing .encode() method. These two methods provide direct access
1555 to the corresponding decoders and encoders of the registered codecs.
1556
1557 To enhance the usability of the .encode() method, the special
1558 casing of Unicode object return values was dropped (Unicode objects
1559 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001560
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001561 Both methods will now return whatever the codec in charge of the
1562 requested encoding returns as object, e.g. Unicode codecs will
1563 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1564 will return u"äöü"). This enables codec writer to create codecs
1565 for various simple to use conversions.
1566
1567 New codecs were added to demonstrate these new features (the .encode()
1568 and .decode() columns indicate the type of the returned objects):
1569
1570 Name | .encode() | .decode() | Description
1571 ----------------------------------------------------------------------
1572 uu | string | string | UU codec (e.g. for email)
1573 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001574 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001575 zlib | string | string | zlib compression
1576 hex | string | string | 2-byte hex codec
1577 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1578
Mark Hammond2a0af792001-05-14 03:09:36 +00001579- Some operating systems now support the concept of a default Unicode
1580 encoding for file system operations. Notably, Windows supports 'mbcs'
1581 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001582 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001583 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001584
1585 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001586 functions that return filenames (such as os.listdir()) to return Python
1587 string objects pre-encoded using the default file system encoding for
1588 the platform. As this encoding is likely to be different from Python's
1589 default encoding, converting this name to a Unicode object before passing
1590 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001591 would attempt to use its default encoding (generally ASCII) rather than
1592 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001593
Tim Petersa814db52001-05-14 07:05:58 +00001594 In general, this change simply removes surprises when working with
1595 Unicode and the file system, making these operations work as you expect,
1596 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001597 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001598
Tim Peters61dff2b2001-05-08 15:43:37 +00001599- Float (and complex) literals in source code were evaluated to full
1600 precision only when running from a .py file; the same code loaded from a
1601 .pyc (or .pyo) file could suffer numeric differences starting at about the
1602 12th significant decimal digit. For example, on a machine with IEEE-754
1603 floating arithmetic,
1604
1605 x = 9007199254740992.0
1606 print long(x)
1607
1608 printed 9007199254740992 if run directly from .py, but 9007199254740000
1609 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1610 str(float) instead of repr(float) when building code objects. marshal
1611 now uses repr(float) instead, which should reproduce floats to full
1612 machine precision (assuming the platform C float<->string I/O conversion
1613 functions are of good quality).
1614
1615 This may cause floating-point results to change in some cases, and
1616 usually for the better, but may also cause numerically unstable
1617 algorithms to break.
1618
Tim Peters2f228e72001-05-13 00:19:31 +00001619- The implementation of dicts suffers fewer collisions, which has speed
1620 benefits. However, the order in which dict entries appear in dict.keys(),
1621 dict.values() and dict.items() may differ from previous releases for a
1622 given dict. Nothing is defined about this order, so no program should
1623 rely on it. Nevertheless, it's easy to write test cases that rely on the
1624 order by accident, typically because of printing the str() or repr() of a
1625 dict to an "expected results" file. See Lib/test/test_support.py's new
1626 sortdict(dict) function for a simple way to display a dict in sorted
1627 order.
1628
Tim Peters7a3bfc32001-06-12 01:22:22 +00001629- Many other small changes to dicts were made, resulting in faster
1630 operation along the most common code paths.
1631
Guido van Rossum10315822001-05-01 20:54:30 +00001632- Dictionary objects now support the "in" operator: "x in dict" means
1633 the same as dict.has_key(x).
1634
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001635- The update() method of dictionaries now accepts generic mapping
1636 objects. Specifically the argument object must support the .keys()
1637 and __getitem__() methods. This allows you to say, for example,
1638 {}.update(UserDict())
1639
Guido van Rossum10315822001-05-01 20:54:30 +00001640- Iterators were added; this is a generalized way of providing values
1641 to a for loop. See PEP 234. There's a new built-in function iter()
1642 to return an iterator. There's a new protocol to get the next value
1643 from an iterator using the next() method (in Python) or the
1644 tp_iternext slot (in C). There's a new protocol to get iterators
1645 using the __iter__() method (in Python) or the tp_iter slot (in C).
1646 Iterating (i.e. a for loop) over a dictionary generates its keys.
1647 Iterating over a file generates its lines.
1648
Tim Petersf553f892001-05-01 20:45:31 +00001649- The following functions were generalized to work nicely with iterator
1650 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001651 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001652 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1653 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001654 join() method of strings
1655 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001656 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1657 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001658 right-hand side of assignment statements with multiple targets, such as
1659 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001660
Tim Petersd85e1022001-05-11 21:51:48 +00001661- Accessing module attributes is significantly faster (for example,
1662 random.random or os.path or yourPythonModule.yourAttribute).
1663
Tim Peterse63415e2001-05-08 04:38:29 +00001664- Comparing dictionary objects via == and != is faster, and now works even
1665 if the keys and values don't support comparisons other than ==.
1666
Tim Peters95bf9392001-05-10 08:32:44 +00001667- Comparing dictionaries in ways other than == and != is slower: there were
1668 insecurities in the dict comparison implementation that could cause Python
1669 to crash if the element comparison routines for the dict keys and/or
1670 values mutated the dicts. Making the code bulletproof slowed it down.
1671
Tim Peterseb28ef22001-06-02 05:27:19 +00001672- Collisions in dicts are resolved via a new approach, which can help
1673 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001674 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001675 faster now. Thanks to Christian Tismer for pointing out the cause and
1676 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001677
Tim Peters52e155e2001-06-16 05:42:57 +00001678- repr() is much faster for large containers (dict, list, tuple).
1679
1680
Tim Petersa814db52001-05-14 07:05:58 +00001681Library
1682
Fred Drake960fdf92001-07-20 18:38:26 +00001683- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1684 were added to the string module. These a locale-indenpendent
1685 constants, unlike letters, lowercase, and uppercase. These are now
1686 use in appropriate locations in the standard library.
1687
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001688- The flags used in dlopen calls can now be configured using
1689 sys.setdlopenflags and queried using sys.getdlopenflags.
1690
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001691- Fredrik Lundh's xmlrpclib is now a standard library module. This
1692 provides full client-side XML-RPC support. In addition,
1693 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1694 one asyncore-based). Thanks to Eric Raymond for the documentation.
1695
Guido van Rossum643d3912001-07-05 14:46:25 +00001696- The xrange() object is simplified: it no longer supports slicing,
1697 repetition, comparisons, efficient 'in' checking, the tolist()
1698 method, or the start, stop and step attributes. See PEP 260.
1699
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001700- A new function fnmatch.filter to filter lists of file names was added.
1701
Barry Warsawffd674d2001-05-22 16:00:10 +00001702- calendar.py uses month and day names based on the current locale.
1703
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001704- strop is now *really* obsolete (this was announced before with 1.6),
1705 and issues DeprecationWarning when used (except for the four items
1706 that are still imported into string.py).
1707
Tim Petersa814db52001-05-14 07:05:58 +00001708- Cookie.py now sorts key+value pairs by key in output strings.
1709
1710- pprint.isrecursive(object) didn't correctly identify recursive objects.
1711 Now it does.
1712
Tim Peters95b3f782001-05-14 18:39:41 +00001713- pprint functions now much faster for large containers (tuple, list, dict).
1714
Tim Peters7b9542a2001-06-10 23:40:19 +00001715- New 'q' and 'Q' format codes in the struct module, corresponding to C
1716 types "long long" and "unsigned long long" (on Windows, __int64). In
1717 native mode, these can be used only when the platform C compiler supports
1718 these types (when HAVE_LONG_LONG is #define'd by the Python config
1719 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001720 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1721 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001722
Guido van Rossum83213cc2001-06-12 16:48:52 +00001723- The site module installs a new built-in function 'help' that invokes
1724 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1725 it displays a message reminding the user to use 'help()' or
1726 'help(object)'.
1727
Tim Petersa814db52001-05-14 07:05:58 +00001728Tests
1729
1730- New test_mutants.py runs dict comparisons where the key and value
1731 comparison operators mutute the dicts randomly during comparison. This
1732 rapidly causes Python to crash under earlier releases (not for the faint
1733 of heart: it can also cause Win9x to freeze or reboot!).
1734
1735- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001736 pprint.isreadable() return sensible results. Also verifies that simple
1737 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001738
Tim Peters4324aa32001-05-28 22:30:08 +00001739C API
1740
1741- Removed the unused last_is_sticky argument from the internal
1742 _PyTuple_Resize(). If this affects you, you were cheating.
1743
1744
Guido van Rossum55a78992001-07-17 17:22:32 +00001745======================================================================
1746
1747
Guido van Rossumffe13be2001-04-16 18:46:45 +00001748What's New in Python 2.1 (final)?
1749=================================
1750
1751We only changed a few things since the last release candidate, all in
1752Python library code:
1753
1754- A bug in the locale module was fixed that affected locales which
1755 define no grouping for numeric formatting.
1756
1757- A few bugs in the weakref module's implementations of weak
1758 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1759 and the test suite was updated to check for these bugs.
1760
1761- An old bug in the os.path.walk() function (introduced in Python
1762 2.0!) was fixed: a non-existent file would cause an exception
1763 instead of being ignored.
1764
1765- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1766 PyChecker.
1767
1768
Guido van Rossum5b08f132001-04-16 02:05:23 +00001769What's New in Python 2.1c2?
1770===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001771
Guido van Rossum5b08f132001-04-16 02:05:23 +00001772A flurry of small changes, and one showstopper fixed in the nick of
1773time made it necessary to release another release candidate. The list
1774here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001775
Guido van Rossum5b08f132001-04-16 02:05:23 +00001776Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001777
Guido van Rossum5b08f132001-04-16 02:05:23 +00001778- Tim discovered a nasty bug in the dictionary code, caused by
1779 PyDict_Next() calling dict_resize(), and the GC code's use of
1780 PyDict_Next() violating an assumption in dict_items(). This was
1781 fixed with considerable amounts of band-aid, but the net effect is a
1782 saner and more robust implementation.
1783
1784- Made a bunch of symbols static that were accidentally global.
1785
1786Build and Ports
1787
1788- The setup.py script didn't check for a new enough version of zlib
1789 (1.1.3 is needed). Now it does.
1790
1791- Changed "make clean" target to also remove shared libraries.
1792
1793- Added a more general warning about the SGI Irix optimizer to README.
1794
1795Library
1796
1797- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1798 omitted the slash between host and file.html.
1799
1800- The mailbox module's _Mailbox class contained a completely broken
1801 and undocumented seek() method. Ripped it out.
1802
1803- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1804 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1805
1806- Fixed a few last-minute bugs in unittest.
1807
1808Extensions
1809
1810- Reverted the patch to the OpenSSL code in socketmodule.c to support
1811 RAND_status() and the EGD, and the subsequent patch that tried to
1812 fix it for pre-0.9.5 versions; the problem with the patch is that on
1813 some systems it issues a warning whenever socket is imported, and
1814 that's unacceptable.
1815
1816Tests
1817
1818- Fixed the pickle tests to work with "import test.test_pickle".
1819
1820- Tweaked test_locale.py to actually run the test Windows.
1821
1822- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1823 not "wb" (which is not a valid mode at all).
1824
1825- Fix pstats browser crashes. Import readline if it exists to make
1826 the user interface nicer.
1827
1828- Add "import thread" to the top of test modules that import the
1829 threading module (test_asynchat and test_threadedtempfile). This
1830 prevents test failures caused by a broken threading module resulting
1831 from a previously caught failed import.
1832
1833- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1834 needed on some platforms (e.g. Solaris 8) when the tests are run
1835 twice in succession.
1836
1837- Skip rather than fail test_sunaudiodev if no audio device is found.
1838
1839
1840What's New in Python 2.1c1?
1841===========================
1842
1843This list was significantly updated when 2.1c2 was released; the 2.1c1
1844release didn't mention most changes that were actually part of 2.1c1:
1845
1846Legal
1847
1848- Copyright was assigned to the Python Software Foundation (PSF) and a
1849 PSF license (very similar to the CNRI license) was added.
1850
1851- The CNRI copyright notice was updated to include 2001.
1852
1853Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001854
Guido van Rossumc9932722001-04-12 02:31:27 +00001855- After a public outcry, assignment to __debug__ is no longer illegal;
1856 instead, a warning is issued. It will become illegal in 2.2.
1857
Guido van Rossum5b08f132001-04-16 02:05:23 +00001858- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1859 "%#x" now always prepends "0x", even if the value is zero.
1860
1861- Fixed some nits in the bytecode compiler.
1862
1863- Fixed core dumps when calling certain kinds of non-functions.
1864
1865- Fixed various core dumps caused by reference count bugs.
1866
1867Build and Ports
1868
1869- Use INSTALL_SCRIPT to install script files.
1870
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001871- New port: SCO Unixware 7, by Billy G. Allie.
1872
Guido van Rossum5b08f132001-04-16 02:05:23 +00001873- Updated RISCOS port.
1874
1875- Updated BeOS port and notes.
1876
1877- Various other porting problems resolved.
1878
1879Library
1880
1881- The TERMIOS and SOCKET modules are now truly obsolete and
1882 unnecessary. Their symbols are incorporated in the termios and
1883 socket modules.
1884
1885- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1886 better tests for pickling.
1887
1888- threading: make Condition.wait() robust against KeyboardInterrupt.
1889
1890- zipfile: add support to zipfile to support opening an archive
1891 represented by an open file rather than a file name. Fix bug where
1892 the archive was not properly closed. Fixed a bug in this bugfix
1893 where flush() was called for a read-only file.
1894
1895- imputil: added an uninstall() method to the ImportManager.
1896
1897- Canvas: fixed bugs in lower() and tkraise() methods.
1898
1899- SocketServer: API change (added overridable close_request() method)
1900 so that the TCP server can explicitly close the request.
1901
1902- pstats: Eric Raymond added a simple interactive statistics browser,
1903 invoked when the module is run as a script.
1904
1905- locale: fixed a problem in format().
1906
1907- webbrowser: made it work when the BROWSER environment variable has a
1908 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1909 KDE 2. Fixed some other nits.
1910
1911- unittest: changes to allow using a different exception than
1912 AssertionError, and added a few more function aliases. Some other
1913 small changes.
1914
1915- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1916
1917- asynchat: fixed a critical bug in asynchat that slipped through the
1918 2.1b2 release. Fixed another rare bug.
1919
1920- Fix some unqualified except: clauses (always a bad code example).
1921
1922XML
1923
1924- pyexpat: new API get_version_string().
1925
1926- Fixed some minidom bugs.
1927
1928Extensions
1929
1930- Fixed a core dump in _weakref. Removed the weakref.mapping()
1931 function (it adds nothing to the API).
1932
1933- Rationalized the use of header files in the readline module, to make
1934 it compile (albeit with some warnings) with the very recent readline
1935 4.2, without breaking for earlier versions.
1936
1937- Hopefully fixed a buffering problem in linuxaudiodev.
1938
1939- Attempted a fix to make the OpenSSL support in the socket module
1940 work again with pre-0.9.5 versions of OpenSSL.
1941
1942Tests
1943
1944- Added a test case for asynchat and asyncore.
1945
1946- Removed coupling between tests where one test failing could break
1947 another.
1948
1949Tools
1950
1951- Ping added an interactive help browser to pydoc, fixed some nits
1952 in the rest of the pydoc code, and added some features to his
1953 inspect module.
1954
1955- An updated python-mode.el version 4.1 which integrates Ken
1956 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1957 much nicer in XEmacs and Emacs. When stepping through your program
1958 with pdb, in either the shell window or the *Python* window, the
1959 source file and line will be tracked by an arrow. Very cool!
1960
1961- IDLE: syntax warnings in interactive mode are changed into errors.
1962
1963- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001964 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001965
1966- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001967
Barry Warsaw11e89c72001-04-11 20:37:57 +00001968
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001969What's New in Python 2.1 beta 2?
1970================================
1971
Guido van Rossum053ae352001-03-22 14:17:21 +00001972(Unlisted are many fixed bugs, more documentation, etc.)
1973
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001974Core language, builtins, and interpreter
1975
Guido van Rossum053ae352001-03-22 14:17:21 +00001976- The nested scopes work (enabled by "from __future__ import
1977 nested_scopes") is completed; in particular, the future now extends
1978 into code executed through exec, eval() and execfile(), and into the
1979 interactive interpreter.
1980
1981- When calling a base class method (e.g. BaseClass.__init__(self)),
1982 this is now allowed even if self is not strictly spoken a class
1983 instance (e.g. when using metaclasses or the Don Beaudry hook).
1984
1985- Slice objects are now comparable but not hashable; this prevents
1986 dict[:] from being accepted but meaningless.
1987
1988- Complex division is now calculated using less braindead algorithms.
1989 This doesn't change semantics except it's more likely to give useful
1990 results in extreme cases. Complex repr() now uses full precision
1991 like float repr().
1992
1993- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1994
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001995- It is illegal to assign to the name __debug__, which is set when the
1996 interpreter starts. It is effectively a compile-time constant.
1997
1998- A warning will be issued if a global statement for a variable
1999 follows a use or assignment of that variable.
2000
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002001Standard library
2002
Guido van Rossum053ae352001-03-22 14:17:21 +00002003- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2004 inspired by JUnit), is now part of the standard library. You now
2005 have a choice of two testing frameworks: unittest requires you to
2006 write testcases as separate code, doctest gathers them from
2007 docstrings. Both approaches have their advantages and
2008 disadvantages.
2009
2010- A new module Tix was added, which wraps the Tix extension library
2011 for Tk. With that module, it is not necessary to statically link
2012 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2013 require" command. See Demo/tix/.
2014
2015- tzparse.py is now obsolete.
2016
2017- In gzip.py, the seek() and tell() methods are removed -- they were
2018 non-functional anyway, and it's better if callers can test for their
2019 existence with hasattr().
2020
2021Python/C API
2022
2023- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2024 that's already in the dictionary during a PyDict_Next() iteration.
2025 This used to fail occasionally when a dictionary resize operation
2026 could be triggered that would rehash all the keys. All other
2027 modifications to the dictionary are still off-limits during a
2028 PyDict_Next() iteration!
2029
2030- New extended APIs related to passing compiler variables around.
2031
2032- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2033 implement isinstance() and issubclass().
2034
2035- Py_BuildValue() now has a "D" conversion to create a Python complex
2036 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002037
Fred Drake4e262a92001-03-22 18:26:47 +00002038- Extensions types which support weak references must now set the
2039 field allocated for the weak reference machinery to NULL themselves;
2040 this is done to avoid the cost of checking each object for having a
2041 weakly referencable type in PyObject_INIT(), since most types are
2042 not weakly referencable.
2043
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002044- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2045 free variables and cell variables to and from the frame's f_locals.
2046
2047- Variants of several functions defined in pythonrun.h have been added
2048 to support the nested_scopes future statement. The variants all end
2049 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2050 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2051 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002052 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002053
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002054Distutils
2055
2056- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2057 into the release tree.
2058
Tim Peters0e57abf2001-05-02 07:39:38 +00002059- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002060 (an uninstaller, more customization of the installer's display)
2061
2062- from Jack Jansen: added Mac-specific code to generate a dialog for
2063 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002064 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002065 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002066
2067- added 'platforms' and 'keywords' to the set of metadata that can be
2068 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002069
2070- applied patches from Jason Tishler to make the compiler class work with
2071 Cygwin.
2072
2073
Tim Peters2fe289a2001-03-01 22:19:38 +00002074What's New in Python 2.1 beta 1?
2075================================
Tim Petersd66595f2001-02-04 03:09:53 +00002076
2077Core language, builtins, and interpreter
2078
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002079- Following an outcry from the community about the amount of code
2080 broken by the nested scopes feature introduced in 2.1a2, we decided
2081 to make this feature optional, and to wait until Python 2.2 (or at
2082 least 6 months) to make it standard. The option can be enabled on a
2083 per-module basis by adding "from __future__ import nested_scopes" at
2084 the beginning of a module (before any other statements, but after
2085 comments and an optional docstring). See PEP 236 (Back to the
2086 __future__) for a description of the __future__ statement. PEP 227
2087 (Statically Nested Scopes) has been updated to reflect this change,
2088 and to clarify the semantics in a number of endcases.
2089
2090- The nested scopes code, when enabled, has been hardened, and most
2091 bugs and memory leaks in it have been fixed.
2092
2093- Compile-time warnings are now generated for a number of conditions
2094 that will break or change in meaning when nested scopes are enabled:
2095
2096 - Using "from...import *" or "exec" without in-clause in a function
2097 scope that also defines a lambda or nested function with one or
2098 more free (non-local) variables. The presence of the import* or
2099 bare exec makes it impossible for the compiler to determine the
2100 exact set of local variables in the outer scope, which makes it
2101 impossible to determine the bindings for free variables in the
2102 inner scope. To avoid the warning about import *, change it into
2103 an import of explicitly name object, or move the import* statement
2104 to the global scope; to avoid the warning about bare exec, use
2105 exec...in... (a good idea anyway -- there's a possibility that
2106 bare exec will be deprecated in the future).
2107
2108 - Use of a global variable in a nested scope with the same name as a
2109 local variable in a surrounding scope. This will change in
2110 meaning with nested scopes: the name in the inner scope will
2111 reference the variable in the outer scope rather than the global
2112 of the same name. To avoid the warning, either rename the outer
2113 variable, or use a global statement in the inner function.
2114
Neil Schemenauera35c6882001-02-27 04:45:05 +00002115- An optional object allocator has been included. This allocator is
2116 optimized for Python objects and should be faster and use less memory
2117 than the standard system allocator. It is not enabled by default
2118 because of possible thread safety problems. The allocator is only
2119 protected by the Python interpreter lock and it is possible that some
2120 extension modules require a thread safe allocator. The object
2121 allocator can be enabled by providing the "--with-pymalloc" option to
2122 configure.
2123
Tim Petersd66595f2001-02-04 03:09:53 +00002124Standard library
2125
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002126- pyexpat now detects the expat version if expat.h defines it. A
2127 number of additional handlers are provided, which are only available
2128 since expat 1.95. In addition, the methods SetParamEntityParsing and
2129 GetInputContext of Parser objects are available with 1.95.x
2130 only. Parser objects now provide the ordered_attributes and
2131 specified_attributes attributes. A new module expat.model was added,
2132 which offers a number of additional constants if 1.95.x is used.
2133
2134- xml.dom offers the new functions registerDOMImplementation and
2135 getDOMImplementation.
2136
2137- xml.dom.minidom offers a toprettyxml method. A number of DOM
2138 conformance issues have been resolved. In particular, Element now
2139 has an hasAttributes method, and the handling of namespaces was
2140 improved.
2141
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002142- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2143 getting information about live Python code, and pydoc.py, a module
2144 for interactively converting docstrings to HTML or text.
2145 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002146 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002147 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2148 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002149
Tim Peters1eff7962001-03-01 02:31:33 +00002150- New library module difflib.py, primarily packaging the SequenceMatcher
2151 class at the heart of the popular ndiff.py file-comparison tool.
2152
2153- doctest.py (a framework for verifying Python code examples in docstrings)
2154 is now part of the std library.
2155
Tim Petersd66595f2001-02-04 03:09:53 +00002156Windows changes
2157
Guido van Rossume3955a82001-03-02 14:05:59 +00002158- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2159 small GUI that lets you browse the module docstrings using your
2160 default web browser.
2161
Tim Peters1eff7962001-03-01 02:31:33 +00002162- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2163 Platforms) is implemented. See
2164
2165 http://python.sourceforge.net/peps/pep-0235.html
2166
2167 for full details, especially the "Current Lower-Left Semantics" section.
2168 The new Windows import rules are simpler than before:
2169
2170 A. If the PYTHONCASEOK environment variable exists, same as
2171 before: silently accept the first case-insensitive match of any
2172 kind; raise ImportError if none found.
2173
2174 B. Else search sys.path for the first case-sensitive match; raise
2175 ImportError if none found.
2176
2177 The same rules have been implented on other platforms with case-
2178 insensitive but case-preserving filesystems too (including Cygwin, and
2179 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002180
Tim Peters25a9ce32001-02-19 07:06:36 +00002181- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2182 what it's supposed to do (and does do under NT and 2000) via direct
2183 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002184 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002185 all Win9x systems before.
2186
Tim Peters1eff7962001-03-01 02:31:33 +00002187- Build: Subproject _test (effectively) renamed to _testcapi.
2188
Tim Peters2fe289a2001-03-01 22:19:38 +00002189New platforms
2190
2191- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2192 Thanks to Steven Majewski!
2193
2194- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2195 Tishler!
2196
Guido van Rossum9089b272001-03-02 06:49:50 +00002197- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2198 Schwertberger! See RISCOS/README for more information -- it seems
2199 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002200 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002201
Tim Peters25a9ce32001-02-19 07:06:36 +00002202
Tim Petersd7b5e882001-01-25 03:36:26 +00002203What's New in Python 2.1 alpha 2?
2204=================================
Tim Peters40ead762001-01-27 05:35:26 +00002205
Tim Petersd7b5e882001-01-25 03:36:26 +00002206Core language, builtins, and interpreter
2207
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002208- Scopes nest. If a name is used in a function or class, but is not
2209 local, the definition in the nearest enclosing function scope will
2210 be used. One consequence of this change is that lambda statements
2211 could reference variables in the namespaces where the lambda is
2212 defined. In some unusual cases, this change will break code.
2213
2214 In all previous version of Python, names were resolved in exactly
2215 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002216 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002217 function A is defined within a function B, the names bound in B are
2218 not visible in A. The new rules make names bound in B visible in A,
2219 unless A contains a name binding that hides the binding in B.
2220
2221 Section 4.1 of the reference manual describes the new scoping rules
2222 in detail. The test script in Lib/test/test_scope.py demonstrates
2223 some of the effects of the change.
2224
2225 The new rules will cause existing code to break if it defines nested
2226 functions where an outer function has local variables with the same
2227 name as globals or builtins used by the inner function. Example:
2228
2229 def munge(str):
2230 def helper(x):
2231 return str(x)
2232 if type(str) != type(''):
2233 str = helper(str)
2234 return str.strip()
2235
2236 Under the old rules, the name str in helper() is bound to the
2237 builtin function str(). Under the new rules, it will be bound to
2238 the argument named str and an error will occur when helper() is
2239 called.
2240
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002241- The compiler will report a SyntaxError if "from ... import *" occurs
2242 in a function or class scope. The language reference has documented
2243 that this case is illegal, but the compiler never checked for it.
2244 The recent introduction of nested scope makes the meaning of this
2245 form of name binding ambiguous. In a future release, the compiler
2246 may allow this form when there is no possibility of ambiguity.
2247
Tim Peters40ead762001-01-27 05:35:26 +00002248- repr(string) is easier to read, now using hex escapes instead of octal,
2249 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2250
2251 >>> "\texample \r\n" + chr(0) + chr(255)
2252 '\texample \r\n\x00\xff' # in 2.1
2253 '\011example \015\012\000\377' # in 2.0
2254
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002255- Functions are now compared and hashed by identity, not by value, since
2256 the func_code attribute is writable.
2257
Fred Drakefb9d7122001-02-01 20:00:40 +00002258- Weak references (PEP 205) have been added. This involves a few
2259 changes in the core, an extension module (_weakref), and a Python
2260 module (weakref). The weakref module is the public interface. It
2261 includes support for "explicit" weak references, proxy objects, and
2262 mappings with weakly held values.
2263
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002264- A 'continue' statement can now appear in a try block within the body
2265 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002266 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002267
Tim Petersd7b5e882001-01-25 03:36:26 +00002268Standard library
2269
Barry Warsaw30dbd142001-01-31 22:14:01 +00002270- mailbox.py now has a new class, PortableUnixMailbox which is
2271 identical to UnixMailbox but uses a more portable scheme for
2272 determining From_ separators. Also, the constructors for all the
2273 classes in this module have a new optional `factory' argument, which
2274 is a callable used when new message classes must be instantiated by
2275 the next() method.
2276
Tim Petersd7b5e882001-01-25 03:36:26 +00002277- random.py is now self-contained, and offers all the functionality of
2278 the now-deprecated whrandom.py. See the docs for details. random.py
2279 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002280 and restoring the internal state of the generator; and jumpahead(n),
2281 for quickly forcing the internal state to be the same as if n calls to
2282 random() had been made. The latter is particularly useful for multi-
2283 threaded programs, creating one instance of the random.Random() class for
2284 each thread, then using .jumpahead() to force each instance to use a
2285 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002286
Tim Peters0de88fc2001-02-01 04:59:18 +00002287- random.py's seed() function is new. For bit-for-bit compatibility with
2288 prior releases, use the whseed function instead. The new seed function
2289 addresses two problems: (1) The old function couldn't produce more than
2290 about 2**24 distinct internal states; the new one about 2**45 (the best
2291 that can be done in the Wichmann-Hill generator). (2) The old function
2292 sometimes produced identical internal states when passed distinct
2293 integers, and there was no simple way to predict when that would happen;
2294 the new one guarantees to produce distinct internal states for all
2295 arguments in [0, 27814431486576L).
2296
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002297- The socket module now supports raw packets on Linux. The socket
2298 family is AF_PACKET.
2299
Tim Peters9ea17ac2001-02-02 05:57:15 +00002300- test_capi.py is a start at running tests of the Python C API. The tests
2301 are implemented by the new Modules/_testmodule.c.
2302
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002303- A new extension module, _symtable, provides provisional access to the
2304 internal symbol table used by the Python compiler. A higher-level
2305 interface will be added on top of _symtable in a future release.
2306
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002307- Removed the obsolete soundex module.
2308
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002309- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2310 the isSameNode method; NamedNodeMap the get method.
2311
2312- xml.sax.expatreader supports the lexical handler property; it
2313 generates comment, startCDATA, and endCDATA events.
2314
Tim Petersee826f82001-01-31 19:39:44 +00002315Windows changes
2316
2317- Build procedure: the zlib project is built in a different way that
2318 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002319 the zlib binary used. See PCbuild\readme.txt for details. Your old
2320 zlib-related directories can be deleted; you'll need to download fresh
2321 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002322
Tim Peters9ea17ac2001-02-02 05:57:15 +00002323- Build: New subproject _test for the benefit of test_capi.py (see above).
2324
Tim Petersb16c56f2001-02-02 21:24:51 +00002325- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2326 interface to some Python compiler internals).
2327
2328- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002329 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002330
Tim Petersa3a3a032000-11-30 05:22:44 +00002331What's New in Python 2.1 alpha 1?
2332=================================
2333
2334Core language, builtins, and interpreter
2335
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002336- There is a new Unicode companion to the PyObject_Str() API
2337 called PyObject_Unicode(). It behaves in the same way as the
2338 former, but assures that the returned value is an Unicode object
2339 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002340
Guido van Rossumf98eda02001-01-17 15:54:45 +00002341- The comparison operators support "rich comparison overloading" (PEP
2342 207). C extension types can provide a rich comparison function in
2343 the new tp_richcompare slot in the type object. The cmp() function
2344 and the C function PyObject_Compare() first try the new rich
2345 comparison operators before trying the old 3-way comparison. There
2346 is also a new C API PyObject_RichCompare() (which also falls back on
2347 the old 3-way comparison, but does not constrain the outcome of the
2348 rich comparison to a Boolean result).
2349
2350 The rich comparison function takes two objects (at least one of
2351 which is guaranteed to have the type that provided the function) and
2352 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2353 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2354 object, which may be NotImplemented (in which case the tp_compare
2355 slot function is used as a fallback, if defined).
2356
2357 Classes can overload individual comparison operators by defining one
2358 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002359 __ge__. There are no explicit "reflected argument" versions of
2360 these; instead, __lt__ and __gt__ are each other's reflection,
2361 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2362 reflection (similar at the C level). No other implications are
2363 made; in particular, Python does not assume that == is the Boolean
2364 inverse of !=, or that < is the Boolean inverse of >=. This makes
2365 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002366
2367 Classes or types that want to implement (in)equality tests but not
2368 the ordering operators (i.e. unordered types) should implement ==
2369 and !=, and raise an error for the ordering operators.
2370
Guido van Rossuma88479f2001-01-18 14:28:08 +00002371 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002372 Boolean; e.g. a matrix type might want to return a matrix of bits
2373 for A < B, giving elementwise comparisons. Such types should ensure
2374 that any interpretation of their value in a Boolean context raises
2375 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2376 at the C level) to always raise an exception.
2377
Guido van Rossuma88479f2001-01-18 14:28:08 +00002378- Complex numbers use rich comparisons to define == and != but raise
2379 an exception for <, <=, > and >=. Unfortunately, this also means
2380 that cmp() of two complex numbers raises an exception when the two
2381 numbers differ. Since it is not mathematically meaningful to compare
2382 complex numbers except for equality, I hope that this doesn't break
2383 too much code.
2384
Tim Peters3389f192001-02-18 08:48:49 +00002385- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002386 not defined by the language, other than that it's arbitrary but
2387 consistent (see the Reference Manual). An implementation detail changed
2388 in 2.1a1 such that None now compares less than any other object. Code
2389 relying on this new behavior (like code that relied on the previous
2390 behavior) does so at its own risk.
2391
Barry Warsaw573b5412001-01-15 20:43:18 +00002392- Functions and methods now support getting and setting arbitrarily
2393 named attributes (PEP 232). Functions have a new __dict__
2394 (a.k.a. func_dict) which hold the function attributes. Methods get
2395 and set attributes on their underlying im_func. It is a TypeError
2396 to set an attribute on a bound method.
2397
Guido van Rossum051e3352001-01-15 19:11:10 +00002398- The xrange() object implementation has been improved so that
2399 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2400 limitation that in this case len(xrange(sys.maxint)) can't be
2401 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2402 work fine as long as the index i doesn't actually reach 2**31.
2403 (Python uses regular ints for sequence and string indices; fixing
2404 that is much more work.)
2405
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002406- Two changes to from...import:
2407
Guido van Rossumba381232001-02-03 15:06:40 +00002408 1) "from M import X" now works even if (after loading module M)
2409 sys.modules['M'] is not a real module; it's basically a getattr()
2410 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002411
2412 2) "from M import *" now looks for M.__all__ to decide which names to
2413 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2414 filters out names starting with '_' as before. Whether or not
2415 __all__ exists, there's no restriction on the type of M.
2416
Guido van Rossumf61f1662001-01-10 20:13:55 +00002417- File objects have a new method, xreadlines(). This is the fastest
2418 way to iterate over all lines in a file:
2419
2420 for line in file.xreadlines():
2421 ...do something to line...
2422
2423 See the xreadlines module (mentioned below) for how to do this for
2424 other file-like objects.
2425
2426- Even if you don't use file.xreadlines(), you may expect a speedup on
2427 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002428 quite a bit in platform-specific ways: on systems (like Linux) that
2429 support flockfile(), getc_unlocked(), and funlockfile(), those are
2430 used by default. On systems (like Windows) without getc_unlocked(),
2431 a complicated (but still thread-safe) method using fgets() is used by
2432 default.
2433
Tim Petersd52269b2001-01-25 06:23:18 +00002434 You can force use of the fgets() method by #define'ing
2435 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002436 getc_unlocked()).
2437
Tim Petersd52269b2001-01-25 06:23:18 +00002438 You can force fgets() not to be used by #define'ing
2439 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002440 test_bufio.py fails -- and let us know if it does!).
2441
2442- In addition, the fileinput module, while still slower than the other
2443 methods on most platforms, has been sped up too, by using
2444 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002445
2446- Support for run-time warnings has been added, including a new
2447 command line option (-W) to specify the disposition of warnings.
2448 See the description of the warnings module below.
2449
2450- Extensive changes have been made to the coercion code. This mostly
2451 affects extension modules (which can now implement mixed-type
2452 numerical operators without having to use coercion), but
2453 occasionally, in boundary cases the coercion semantics have changed
2454 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002455 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002456 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002457 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002458
Guido van Rossumf98eda02001-01-17 15:54:45 +00002459- In connection with the coercion changes, a new built-in singleton
2460 object, NotImplemented is defined. This can be returned for
2461 operations that wish to indicate they are not implemented for a
2462 particular combination of arguments. From C, this is
2463 Py_NotImplemented.
2464
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002465- The interpreter accepts now bytecode files on the command line even
2466 if they do not have a .pyc or .pyo extension. On Linux, after executing
2467
Martin v. Löwise214baa2001-02-04 22:37:56 +00002468import imp,sys,string
2469magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2470reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2471open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002472
2473 any byte code file can be used as an executable (i.e. as an argument
2474 to execve(2)).
2475
Tim Peters9940b802000-12-01 07:59:35 +00002476- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002477 character. In 1.6 and earlier, they never produced a sign,
2478 and raised an error if the value of the long was too large
2479 to fit in a Python int. In 2.0, they produced a sign if and
2480 only if too large to fit in an int. This was inconsistent
2481 across platforms (because the size of an int varies across
2482 platforms), and inconsistent with hex() and oct(). Example:
2483
2484 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002485 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002486 'ffffffbe' # in 2.0 and before, on 32-bit machines
2487 >>> hex(-0x42L)
2488 '-0x42L' # in all versions of Python
2489
Tim Peters9940b802000-12-01 07:59:35 +00002490 The behavior of %d formats for negative Python longs remains
2491 the same as in 2.0 (although in 1.6 and before, they raised
2492 an error if the long didn't fit in a Python int).
2493
2494 %u formats don't make sense for Python longs, but are allowed
2495 and treated the same as %d in 2.1. In 2.0, a negative long
2496 formatted via %u produced a sign if and only if too large to
2497 fit in an int. In 1.6 and earlier, a negative long formatted
2498 via %u raised an error if it was too big to fit in an int.
2499
Guido van Rossum3661d392000-12-12 22:10:31 +00002500- Dictionary objects have an odd new method, popitem(). This removes
2501 an arbitrary item from the dictionary and returns it (in the form of
2502 a (key, value) pair). This can be useful for algorithms that use a
2503 dictionary as a bag of "to do" items and repeatedly need to pick one
2504 item. Such algorithms normally end up running in quadratic time;
2505 using popitem() they can usually be made to run in linear time.
2506
Tim Peters36cdad12000-12-29 02:06:45 +00002507Standard library
2508
Thomas Woutersfe385252001-01-19 23:16:56 +00002509- In the time module, the time argument to the functions strftime,
2510 localtime, gmtime, asctime and ctime is now optional, defaulting to
2511 the current time (in the local timezone).
2512
Guido van Rossumda91f222001-01-15 16:36:08 +00002513- The ftplib module now defaults to passive mode, which is deemed a
2514 more useful default given that clients are often inside firewalls
2515 these days. Note that this could break if ftplib is used to connect
2516 to a *server* that is inside a firewall, from outside; this is
2517 expected to be a very rare situation. To fix that, you can call
2518 ftp.set_pasv(0).
2519
Martin v. Löwis10a27872001-01-13 09:54:41 +00002520- The module site now treats .pth files not only for path configuration,
2521 but also supports extensions to the initialization code: Lines starting
2522 with import are executed.
2523
Guido van Rossumf61f1662001-01-10 20:13:55 +00002524- There's a new module, warnings, which implements a mechanism for
2525 issuing and filtering warnings. There are some new built-in
2526 exceptions that serve as warning categories, and a new command line
2527 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2528 turns warnings into errors). warnings.warn(message[, category])
2529 issues a warning message; this can also be called from C as
2530 PyErr_Warn(category, message).
2531
2532- A new module xreadlines was added. This exports a single factory
2533 function, xreadlines(). The intention is that this code is the
2534 absolutely fastest way to iterate over all lines in an open
2535 file(-like) object:
2536
2537 import xreadlines
2538 for line in xreadlines.xreadlines(file):
2539 ...do something to line...
2540
2541 This is equivalent to the previous the speed record holder using
2542 file.readlines(sizehint). Note that if file is a real file object
2543 (as opposed to a file-like object), this is equivalent:
2544
2545 for line in file.xreadlines():
2546 ...do something to line...
2547
Tim Peters36cdad12000-12-29 02:06:45 +00002548- The bisect module has new functions bisect_left, insort_left,
2549 bisect_right and insort_right. The old names bisect and insort
2550 are now aliases for bisect_right and insort_right. XXX_right
2551 and XXX_left methods differ in what happens when the new element
2552 compares equal to one or more elements already in the list: the
2553 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002554 right. Code that doesn't care where equal elements end up should
2555 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002556
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002557- The new curses.panel module wraps the panel library that forms part
2558 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2559
Guido van Rossumf61f1662001-01-10 20:13:55 +00002560- The SocketServer module now sets the allow_reuse_address flag by
2561 default in the TCPServer class.
2562
2563- A new function, sys._getframe(), returns the stack frame pointer of
2564 the caller. This is intended only as a building block for
2565 higher-level mechanisms such as string interpolation.
2566
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002567- The pyexpat module supports a number of new handlers, which are
2568 available only in expat 1.2. If invocation of a callback fails, it
2569 will report an additional frame in the traceback. Parser objects
2570 participate now in garbage collection. If expat reports an unknown
2571 encoding, pyexpat will try to use a Python codec; that works only
2572 for single-byte charsets. The parser type objects is exposed as
2573 XMLParserObject.
2574
2575- xml.dom now offers standard definitions for symbolic node type and
2576 exception code constants, and a hierarchy of DOM exceptions. minidom
2577 was adjusted to use them.
2578
2579- The conformance of xml.dom.minidom to the DOM specification was
2580 improved. It detects a number of additional error cases; the
2581 previous/next relationship works even when the tree is modified;
2582 Node supports the normalize() method; NamedNodeMap, DocumentType and
2583 DOMImplementation classes were added; Element supports the
2584 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2585 method.
2586
Guido van Rossumf61f1662001-01-10 20:13:55 +00002587Build issues
2588
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002589- For Unix (and Unix-compatible) builds, configuration and building of
2590 extension modules is now greatly automated. Rather than having to
2591 edit the Modules/Setup file to indicate which modules should be
2592 built and where their include files and libraries are, a
2593 distutils-based setup.py script now takes care of building most
2594 extension modules. All extension modules built this way are built
2595 as shared libraries. Only a few modules that must be linked
2596 statically are still listed in the Setup file; you won't need to
2597 edit their configuration.
2598
2599- Python should now build out of the box on Cygwin. If it doesn't,
2600 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002601
2602- Python now always uses its own (renamed) implementation of getopt()
2603 -- there's too much variation among C library getopt()
2604 implementations.
2605
2606- C++ compilers are better supported; the CXX macro is always set to a
2607 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002608
Tim Petersd92dfe02000-12-12 01:18:41 +00002609Windows changes
2610
2611- select module: By default under Windows, a select() call
2612 can specify no more than 64 sockets. Python now boosts
2613 this Microsoft default to 512. If you need even more than
2614 that, see the MS docs (you'll need to #define FD_SETSIZE
2615 and recompile Python from source).
2616
Guido van Rossumf61f1662001-01-10 20:13:55 +00002617- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2618 subdirectory is no more!
2619
Tim Petersa3a3a032000-11-30 05:22:44 +00002620
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002621What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002622=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002623
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002624Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002625changes are in the file HISTORY. If you are making the jump directly
2626from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2627HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002628
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002629Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2630the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2631http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002632
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002633--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002634
2635======================================================================
2636
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002637What's new in 2.0 (since release candidate 1)?
2638==============================================
2639
2640Standard library
2641
2642- The copy_reg module was modified to clarify its intended use: to
2643 register pickle support for extension types, not for classes.
2644 pickle() will raise a TypeError if it is passed a class.
2645
2646- Fixed a bug in gettext's "normalize and expand" code that prevented
2647 it from finding an existing .mo file.
2648
2649- Restored support for HTTP/0.9 servers in httplib.
2650
Tim Peters989b7b92000-10-16 20:24:53 +00002651- The math module was changed to stop raising OverflowError in case of
2652 underflow, and return 0 instead in underflow cases. Whether Python
2653 used to raise OverflowError in case of underflow was platform-
2654 dependent (it did when the platform math library set errno to ERANGE
2655 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002656
2657- Fixed a bug in StringIO that occurred when the file position was not
2658 at the end of the file and write() was called with enough data to
2659 extend past the end of the file.
2660
2661- Fixed a bug that caused Tkinter error messages to get lost on
2662 Windows. The bug was fixed by replacing direct use of
2663 interp->result with Tcl_GetStringResult(interp).
2664
2665- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2666 redirect response.
2667
2668- Several changes were made to distutils: Some debugging code was
2669 removed from util. Fixed the installer used when an external zip
2670 program (like WinZip) is not found; the source code for this
2671 installer is in Misc/distutils. check_lib() was modified to behave
2672 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2673 test for whether installed modules are on sys.path was changed to
2674 use both normcase() and normpath().
2675
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002676- Several minor bugs were fixed in the xml package (the minidom,
2677 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002678
2679- The regression test driver (regrtest.py) behavior when invoked with
2680 -l changed: It now reports a count of objects that are recognized as
2681 garbage but not freed by the garbage collector.
2682
Tim Peters989b7b92000-10-16 20:24:53 +00002683- The regression test for the math module was changed to test
2684 exceptional behavior when the test is run in verbose mode. Python
2685 cannot yet guarantee consistent exception behavior across platforms,
2686 so the exception part of test_math is run only in verbose mode, and
2687 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002688
2689Internals
2690
2691- PyOS_CheckStack() has been disabled on Win64, where it caused
2692 test_sre to fail.
2693
2694Build issues
2695
2696- Changed compiler flags, so that gcc is always invoked with -Wall and
2697 -Wstrict-prototypes. Users compiling Python with GCC should see
2698 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002699 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002700 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002701
Tim Petersa3a3a032000-11-30 05:22:44 +00002702- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002703
2704Tools and other miscellany
2705
2706- The compiler in Tools/compiler was updated to support the new
2707 language features introduced in 2.0: extended print statement, list
2708 comprehensions, and augmented assignments. The new compiler should
2709 also be backwards compatible with Python 1.5.2; the compiler will
2710 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002711 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002712
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002713What's new in 2.0 release candidate 1 (since beta 2)?
2714=====================================================
2715
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002716What is release candidate 1?
2717
2718We believe that release candidate 1 will fix all known bugs that we
2719intend to fix for the 2.0 final release. This release should be a bit
2720more stable than the previous betas. We would like to see even more
2721widespread testing before the final release, so we are producing this
2722release candidate. The final release will be exactly the same unless
2723any show-stopping (or brown bag) bugs are found by testers of the
2724release candidate.
2725
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002726All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002727to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002728
2729Core language, builtins, and interpreter
2730
2731- A bug that caused crashes when __coerce__ was used with augmented
2732 assignment, e.g. +=, was fixed.
2733
2734- Raise ZeroDivisionError when raising zero to a negative number,
2735 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2736 power operator and the result of math.pow(0.0, -2.0) will vary by
2737 platform. On Linux, it raises a ValueError.
2738
2739- A bug in Unicode string interpolation was fixed that occasionally
2740 caused errors with formats including "%%". For example, the
2741 following expression "%% %s" % u"abc" no longer raises a TypeError.
2742
2743- Compilation of deeply nested expressions raises MemoryError instead
2744 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2745
2746- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2747 rendering them useless. They are now written in binary mode again.
2748
2749Standard library
2750
2751- Keyword arguments are now accepted for most pattern and match object
2752 methods in SRE, the standard regular expression engine.
2753
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002754- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002755 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002756
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002757- Several bugs in the Unicode handling and error handling in _tkinter
2758 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002759
2760- Fix memory management errors in Merge() and Tkapp_Call() routines.
2761
2762- Several changes were made to cStringIO to make it compatible with
2763 the file-like object interface and with StringIO. If operations are
2764 performed on a closed object, an exception is raised. The truncate
2765 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002766 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002767
2768- There were many changes made to the linuxaudiodev module and its
2769 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002770 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002771
2772 Note that this module is named poorly, because it should work
2773 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002774 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002775
2776 The module now raises exceptions when errors occur instead of
2777 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2778 audio) and defines a getptr() method that calls the
2779 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2780
2781- The library_version attribute, introduced in an earlier beta, was
2782 removed because it can not be supported with early versions of the C
2783 readline library, which provides no way to determine the version at
2784 compile-time.
2785
2786- The binascii module is now enabled on Win64.
2787
Tim Peters46446d62000-10-09 21:19:31 +00002788- tokenize.py no longer suffers "recursion depth" errors when parsing
2789 programs with very long string literals.
2790
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002791Internals
2792
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002793- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002794 which is called when the interpreter starts up to determine where
2795 the standard library is installed. These vulnerabilities affect all
2796 previous versions of Python and can be exploited by setting very
2797 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2798 setuid Python script, although use of the wrapper in
2799 Misc/setuid-prog.c will eliminate the vulnerability.
2800
2801- Fixed garbage collection bugs in instance creation that were
2802 triggered when errors occurred during initialization. The solution,
2803 applied in cPickle and in PyInstance_New(), is to call
2804 PyObject_GC_Init() after the initialization of the object's
2805 container attributes is complete.
2806
2807- pyexpat adds definitions of PyModule_AddStringConstant and
2808 PyModule_AddObject if the Python version is less than 2.0, which
2809 provides compatibility with PyXML on Python 1.5.2.
2810
2811- If the platform has a bogus definition for LONG_BIT (the number of
2812 bits in a long), an error will be reported at compile time.
2813
2814- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2815 collection crashes and possibly other, unreported crashes.
2816
2817- Fixed a memory leak in _PyUnicode_Fini().
2818
2819Build issues
2820
2821- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002822 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002823 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002824
2825- The mmap.PAGESIZE constant is now initialized using sysconf when
2826 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2827
2828- The md5 file should now compile on all platforms.
2829
2830- The select module now compiles on platforms that do not define
2831 POLLRDNORM and related constants.
2832
2833- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002834 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002835
Jeremy Hylton10921202000-10-09 18:34:12 +00002836- BeOS: A number of changes were made to the build and installation
2837 process. ar-fake now operates on a directory of object files.
2838 dl_export.h is gone, and its macros now appear on the mwcc command
2839 line during build on PPC BeOS.
2840
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002841- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002842 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002843
2844- Cygwin: Support for shared libraries, Tkinter, and sockets.
2845
2846- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2847
2848Tools and other miscellany
2849
2850- Removed debugging prints from main used with freeze.
2851
Tim Peters46446d62000-10-09 21:19:31 +00002852- IDLE auto-indent no longer crashes when it encounters Unicode
2853 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002854
2855What's new in 2.0 beta 2 (since beta 1)?
2856========================================
2857
2858Core language, builtins, and interpreter
2859
Tim Peters482c0212000-09-26 06:33:09 +00002860- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002861 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002862
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002863- Add -h and -V command line options to print the usage message and
2864 Python version number and exit immediately.
2865
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002866- eval() and exec accept Unicode objects as code parameters.
2867
2868- getattr() and setattr() now also accept Unicode objects for the
2869 attribute name, which are converted to strings using the default
2870 encoding before lookup.
2871
2872- Multiplication on string and Unicode now does proper bounds
2873 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2874 string is too long."
2875
2876- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002877 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002878
Jeremy Hylton1b618592000-09-26 05:32:36 +00002879
2880Standard library and extensions
2881
Guido van Rossum5b08f132001-04-16 02:05:23 +00002882- socket module: the OpenSSL code now adds support for RAND_status()
2883 and EGD (Entropy Gathering Device).
2884
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002885- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002886 argument checking; it still takes no arguments.
2887
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002888- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002889
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002890- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002891
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002892- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002893
2894- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002895 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002896
2897- copy: Copy Unicode objects atomically.
2898
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002899- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002900
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002901- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002902
Fred Drake67233bc2000-09-26 16:40:27 +00002903- dbm: Add get() and setdefault() methods to dbm object. Add constant
2904 `library' to module that names the library used. Added doc strings
2905 and method names to error messages. Uses configure to determine
2906 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2907 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002908
2909- distutils: Update to version 0.9.3.
2910
2911- dl: Add several dl.RTLD_ constants.
2912
2913- fpectl: Now supported on FreeBSD.
2914
2915- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2916 found by the collector will be saved in gc.garbage. This is useful
2917 for debugging a program that creates reference cycles.
2918
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002919- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002920 of HTTP class. Do not close socket on zero-length response. Do not
2921 crash when server sends invalid content-length header.
2922
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002923- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002924
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002925- marshal: When reading a short, sign-extend on platforms where shorts
2926 are bigger than 16 bits. When reading a long, repair the unportable
2927 sign extension that was being done for 64-bit machines. (It assumed
2928 that signed right shift sign-extends.)
2929
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002930- operator: Add contains(), invert(), __invert__() as aliases for
2931 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002932
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002933- os: Add support for popen2() and popen3() on all platforms where
2934 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002935
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002936- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002937 clicking on a file in Explorer (or passing the file name to the
2938 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002939
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002940- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002941 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002942
2943- pickle: Now raises ValueError when an invalid pickle that contains
2944 a non-string repr where a string repr was expected. This behavior
2945 matches cPickle.
2946
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002947- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002948
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002949- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002950
2951- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002952 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002953 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002954
2955- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002956 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002957
2958- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002959 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002960 few cycles during startup since the first call to
2961 setdefaultencoding() will initialize the codec registry and the
2962 encodings package.
2963
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002964- socket: Support for size hint in readlines() method of object returned
2965 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002966
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002967- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002968 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002969 is followed by whitespace.
2970
Tim Petersa3a3a032000-11-30 05:22:44 +00002971- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002972
2973- struct: Check ranges for bytes and shorts.
2974
2975- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002976 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002977
2978- Tkinter: Image objects are now guaranteed to have unique ids. Set
2979 event.delta to zero if Tk version doesn't support mousewheel.
2980 Removed some debugging prints.
2981
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002982- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002983
Fred Drake67233bc2000-09-26 16:40:27 +00002984- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002985 which works around a bug in Norton AntiVirus 2000 that leads directly
2986 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002987
2988- xml: New version detection code allows PyXML to override standard
2989 XML package if PyXML version is greater than 0.6.1.
2990
Fred Drake64bb3802000-09-26 16:21:35 +00002991- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2992 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2993 tree only for nodes which are sufficiently interesting to a specific
2994 application. Does not provide the HTML-specific extensions. Still
2995 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002996
Fred Drake64bb3802000-09-26 16:21:35 +00002997- xml.sax: SAX 2 support for Python, including all the handler
2998 interfaces needed to process XML 1.0 compliant XML. Some
2999 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003000
Fred Drake64bb3802000-09-26 16:21:35 +00003001- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3002 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003003
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003004
Jeremy Hylton1b618592000-09-26 05:32:36 +00003005C API
3006
3007- Add three new convenience functions for module initialization --
3008 PyModule_AddObject(), PyModule_AddIntConstant(), and
3009 PyModule_AddStringConstant().
3010
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003011- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003012 removed and add #error to Python.h if NULL isn't defined after
3013 #include of stdio.h.
3014
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003015- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016 backwards compatibility (at the source level) with old extensions.
3017
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003018- A wrapper API was added for signal() and sigaction(). Instead of
3019 either function, always use PyOS_getsig() to get a signal handler
3020 and PyOS_setsig() to set one. A new convenience typedef
3021 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003022
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003023- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024 internal data buffer and size of a string object -- or the default
3025 encoded version of a Unicode object.
3026
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003027- PyString_Size() and PyString_AsString() accept Unicode objects.
3028
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003029- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003030 exists). INT_MAX and LONG_MAX will always be defined, even if
3031 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003032
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003033- PyFloat_FromString takes a second argument, pend, that was
3034 effectively useless. It is now officially useless but preserved for
3035 backwards compatibility. If the pend argument is not NULL, *pend is
3036 set to NULL.
3037
3038- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3039 for the attribute name. See note on getattr() above.
3040
3041- A few bug fixes to argument processing for Unicode.
3042 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3043 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3044 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003045 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003046
3047- Py_BuildValue accepts B format (for bgen-generated code).
3048
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003049
Jeremy Hylton1b618592000-09-26 05:32:36 +00003050Internals
3051
3052- On Unix, fix code for finding Python installation directory so that
3053 it works when argv[0] is a relative path.
3054
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003055- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003056 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003057 rather than by generating a copy of the object.
3058
Tim Peters482c0212000-09-26 06:33:09 +00003059- Several of the internal Unicode tables are much smaller now, and
3060 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003061
Jeremy Hylton97693b02000-09-26 17:42:51 +00003062- In the garbage collector: Fixed bug in collection of tuples. Fixed
3063 bug that caused some instances to be removed from the container set
3064 while they were still live. Fixed parsing in gc.set_debug() for
3065 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003066
3067- Fixed refcount problem in instance deallocation that only occurred
3068 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3069
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003070- On Windows, getpythonregpath is now protected against null data in
3071 registry key.
3072
3073- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003074 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003075
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003076
Jeremy Hylton1b618592000-09-26 05:32:36 +00003077Build and platform-specific issues
3078
3079- Better support of GNU Pth via --with-pth configure option.
3080
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003081- Python/C API now properly exposed to dynamically-loaded extension
3082 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003083
3084- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3085 Don't define MS_SYNC to be zero when it is undefined. Added missing
3086 prototypes in posixmodule.c.
3087
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003088- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003089 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003090
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003091- Fix largefile support on older NetBSD systems and OpenBSD by adding
3092 define for TELL64.
3093
3094
3095Tools and other miscellany
3096
3097- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3098
3099- freeze: The modulefinder now works with 2.0 opcodes.
3100
Tim Petersa3a3a032000-11-30 05:22:44 +00003101- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003102 Move hackery of sys.argv until after the Tk instance has been
3103 created, which allows the application-specific Tkinter
3104 initialization to be executed if present; also pass an explicit
3105 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003106
Jeremy Hylton1b618592000-09-26 05:32:36 +00003107
3108What's new in 2.0 beta 1?
3109=========================
3110
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003111Source Incompatibilities
3112------------------------
3113
3114None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3115such as single-argument append(), connect() and bind(), and changes to
3116str(long) and repr(float).
3117
3118
3119Binary Incompatibilities
3120------------------------
3121
3122- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3123with Python 2.0; these extensions will have to be rebuilt for Python
31242.0.
3125
3126- On Windows, attempting to import a third party extension built for
3127Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3128can do about this. Check your PYTHONPATH environment variable!
3129
3130- Python bytecode files (*.pyc and *.pyo) are not compatible between
3131releases.
3132
3133
3134Overview of Changes Since 1.6
3135-----------------------------
3136
3137There are many new modules (including brand new XML support through
3138the xml package, and i18n support through the gettext module); a list
3139of all new modules is included below. Lots of bugs have been fixed.
3140
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003141The process for making major new changes to the language has changed
3142since Python 1.6. Enhancements must now be documented by a Python
3143Enhancement Proposal (PEP) before they can be accepted.
3144
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003145There are several important syntax enhancements, described in more
3146detail below:
3147
3148 - Augmented assignment, e.g. x += 1
3149
3150 - List comprehensions, e.g. [x**2 for x in range(10)]
3151
3152 - Extended import statement, e.g. import Module as Name
3153
3154 - Extended print statement, e.g. print >> file, "Hello"
3155
3156Other important changes:
3157
3158 - Optional collection of cyclical garbage
3159
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003160Python Enhancement Proposal (PEP)
3161---------------------------------
3162
3163PEP stands for Python Enhancement Proposal. A PEP is a design
3164document providing information to the Python community, or describing
3165a new feature for Python. The PEP should provide a concise technical
3166specification of the feature and a rationale for the feature.
3167
3168We intend PEPs to be the primary mechanisms for proposing new
3169features, for collecting community input on an issue, and for
3170documenting the design decisions that have gone into Python. The PEP
3171author is responsible for building consensus within the community and
3172documenting dissenting opinions.
3173
3174The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003175
3176Augmented Assignment
3177--------------------
3178
3179This must have been the most-requested feature of the past years!
3180Eleven new assignment operators were added:
3181
Guido van Rossume905e952000-09-05 12:42:46 +00003182 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003183
3184For example,
3185
3186 A += B
3187
3188is similar to
3189
3190 A = A + B
3191
3192except that A is evaluated only once (relevant when A is something
3193like dict[index].attr).
3194
3195However, if A is a mutable object, A may be modified in place. Thus,
3196if A is a number or a string, A += B has the same effect as A = A+B
3197(except A is only evaluated once); but if a is a list, A += B has the
3198same effect as A.extend(B)!
3199
3200Classes and built-in object types can override the new operators in
3201order to implement the in-place behavior; the not-in-place behavior is
3202used automatically as a fallback when an object doesn't implement the
3203in-place behavior. For classes, the method name is derived from the
3204method name for the corresponding not-in-place operator by inserting
3205an 'i' in front of the name, e.g. __iadd__ implements in-place
3206__add__.
3207
3208Augmented assignment was implemented by Thomas Wouters.
3209
3210
3211List Comprehensions
3212-------------------
3213
3214This is a flexible new notation for lists whose elements are computed
3215from another list (or lists). The simplest form is:
3216
3217 [<expression> for <variable> in <sequence>]
3218
Guido van Rossum56db0952000-09-06 23:34:25 +00003219For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003220This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003221
3222You can also add a condition:
3223
3224 [<expression> for <variable> in <sequence> if <condition>]
3225
3226For example, [w for w in words if w == w.lower()] would yield the list
3227of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003228than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003229
3230You can also have nested for loops and more than one 'if' clause. For
3231example, here's a function that flattens a sequence of sequences::
3232
3233 def flatten(seq):
3234 return [x for subseq in seq for x in subseq]
3235
3236 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3237
3238This prints
3239
3240 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3241
3242List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003243Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003244
3245
3246Extended Import Statement
3247-------------------------
3248
3249Many people have asked for a way to import a module under a different
3250name. This can be accomplished like this:
3251
3252 import foo
3253 bar = foo
3254 del foo
3255
3256but this common idiom gets old quickly. A simple extension of the
3257import statement now allows this to be written as follows:
3258
3259 import foo as bar
3260
3261There's also a variant for 'from ... import':
3262
3263 from foo import bar as spam
3264
3265This also works with packages; e.g. you can write this:
3266
3267 import test.regrtest as regrtest
3268
3269Note that 'as' is not a new keyword -- it is recognized only in this
3270context (this is only possible because the syntax for the import
3271statement doesn't involve expressions).
3272
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003273Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003274
3275
3276Extended Print Statement
3277------------------------
3278
3279Easily the most controversial new feature, this extension to the print
3280statement adds an option to make the output go to a different file
3281than the default sys.stdout.
3282
3283For example, to write an error message to sys.stderr, you can now
3284write:
3285
3286 print >> sys.stderr, "Error: bad dog!"
3287
3288As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003289evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003290
3291 print >> None, "Hello world"
3292
3293is equivalent to
3294
3295 print "Hello world"
3296
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003297Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003298
3299
3300Optional Collection of Cyclical Garbage
3301---------------------------------------
3302
3303Python is now equipped with a garbage collector that can hunt down
3304cyclical references between Python objects. It's no replacement for
3305reference counting; in fact, it depends on the reference counts being
3306correct, and decides that a set of objects belong to a cycle if all
3307their reference counts can be accounted for from their references to
3308each other. This devious scheme was first proposed by Eric Tiedemann,
3309and brought to implementation by Neil Schemenauer.
3310
3311There's a module "gc" that lets you control some parameters of the
3312garbage collection. There's also an option to the configure script
3313that lets you enable or disable the garbage collection. In 2.0b1,
3314it's on by default, so that we (hopefully) can collect decent user
3315experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003316performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003317off by default in the final 2.0 release.
3318
3319
3320Smaller Changes
3321---------------
3322
3323A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3324map(None, seq1, seq2, ...) when the sequences have the same length;
3325i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3326the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003327zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003328
3329sys.version_info is a tuple (major, minor, micro, level, serial).
3330
3331Dictionaries have an odd new method, setdefault(key, default).
3332dict.setdefault(key, default) returns dict[key] if it exists; if not,
3333it sets dict[key] to default and returns that value. Thus:
3334
3335 dict.setdefault(key, []).append(item)
3336
3337does the same work as this common idiom:
3338
3339 if not dict.has_key(key):
3340 dict[key] = []
3341 dict[key].append(item)
3342
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003343There are two new variants of SyntaxError that are raised for
3344indentation-related errors: IndentationError and TabError.
3345
3346Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3347escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003348
3349The limits on the size of expressions and file in Python source code
3350have been raised from 2**16 to 2**32. Previous versions of Python
3351were limited because the maximum argument size the Python VM accepted
3352was 2**16. This limited the size of object constructor expressions,
3353e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3354limit was raised thanks to a patch by Charles Waldman that effectively
3355fixes the problem. It is now much more likely that you will be
3356limited by available memory than by an arbitrary limit in Python.
3357
3358The interpreter's maximum recursion depth can be modified by Python
3359programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3360limit is the maximum number of recursive calls that can be made by
3361Python code. The limit exists to prevent infinite recursion from
3362overflowing the C stack and causing a core dump. The default value is
33631000. The maximum safe value for a particular platform can be found
3364by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003365
3366New Modules and Packages
3367------------------------
3368
3369atexit - for registering functions to be called when Python exits.
3370
3371imputil - Greg Stein's alternative API for writing custom import
3372hooks.
3373
3374pyexpat - an interface to the Expat XML parser, contributed by Paul
3375Prescod.
3376
3377xml - a new package with XML support code organized (so far) in three
3378subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3379would fill a volume. There's a special feature whereby a
3380user-installed package named _xmlplus overrides the standard
3381xmlpackage; this is intended to give the XML SIG a hook to distribute
3382backwards-compatible updates to the standard xml package.
3383
3384webbrowser - a platform-independent API to launch a web browser.
3385
3386
Guido van Rossume905e952000-09-05 12:42:46 +00003387Changed Modules
3388---------------
3389
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003390array -- new methods for array objects: count, extend, index, pop, and
3391remove
3392
3393binascii -- new functions b2a_hex and a2b_hex that convert between
3394binary data and its hex representation
3395
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003396calendar -- Many new functions that support features including control
3397over which day of the week is the first day, returning strings instead
3398of printing them. Also new symbolic constants for days of week,
3399e.g. MONDAY, ..., SUNDAY.
3400
3401cgi -- FieldStorage objects have a getvalue method that works like a
3402dictionary's get method and returns the value attribute of the object.
3403
3404ConfigParser -- The parser object has new methods has_option,
3405remove_section, remove_option, set, and write. They allow the module
3406to be used for writing config files as well as reading them.
3407
3408ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003409optionally support the RFC 959 REST command.
3410
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003411gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003412
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003413httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3414the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003415
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003416locale -- implement getdefaultlocale for Win32 and Macintosh
3417
3418marshal -- no longer dumps core when marshaling deeply nested or
3419recursive data structures
3420
3421os -- new functions isatty, seteuid, setegid, setreuid, setregid
3422
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003423os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3424support under Unix.
3425
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003426os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003427
3428os.path -- fix semantics of os.path.commonprefix
3429
3430smtplib -- support for sending very long messages
3431
3432socket -- new function getfqdn()
3433
3434readline -- new functions to read, write and truncate history files.
3435The readline section of the library reference manual contains an
3436example.
3437
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003438select -- add interface to poll system call
3439
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003440shutil -- new copyfileobj function
3441
3442SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3443HTTP server.
3444
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003445Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003446
3447urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003448e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003449
3450whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003451
3452
3453Obsolete Modules
3454----------------
3455
3456None. However note that 1.6 made a whole slew of modules obsolete:
3457stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3458poly, zmod, strop, util, whatsound.
3459
3460
3461Changed, New, Obsolete Tools
3462----------------------------
3463
Tim Peters8b092332000-09-05 20:15:25 +00003464None.
Guido van Rossume905e952000-09-05 12:42:46 +00003465
3466
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003467C-level Changes
3468---------------
3469
3470Several cleanup jobs were carried out throughout the source code.
3471
3472All C code was converted to ANSI C; we got rid of all uses of the
3473Py_PROTO() macro, which makes the header files a lot more readable.
3474
3475Most of the portability hacks were moved to a new header file,
3476pyport.h; several other new header files were added and some old
3477header files were removed, in an attempt to create a more rational set
3478of header files. (Few of these ever need to be included explicitly;
3479they are all included by Python.h.)
3480
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003481Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003482and Win64, especially for the new Intel Itanium processor. Mick also
3483added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003484
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003485The C APIs to return an object's size have been update to consistently
3486use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3487previous versions, the abstract interfaces used PyXXX_Length and the
3488concrete interfaces used PyXXX_Size. The old names,
3489e.g. PyObject_Length, are still available for backwards compatibility
3490at the API level, but are deprecated.
3491
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003492The PyOS_CheckStack function has been implemented on Windows by
3493Fredrik Lundh. It prevents Python from failing with a stack overflow
3494on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003495
3496The GC changes resulted in creation of two new slots on object,
3497tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003498the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003499
3500The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003501C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003502
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003503PyErr_Format has been updated to automatically calculate the size of
3504the buffer needed to hold the formatted result string. This change
3505prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003506
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003507New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003508
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003509PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3510that are the same as their non-Ex counterparts except they take an
3511extra flag argument that tells them to close the file when done.
3512
3513XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003514
Tim Peters8b092332000-09-05 20:15:25 +00003515
3516Windows Changes
3517---------------
3518
3519New popen2/popen3/peopen4 in os module (see Changed Modules above).
3520
3521os.popen is much more usable on Windows 95 and 98. See Microsoft
3522Knowledge Base article Q150956. The Win9x workaround described there
3523is implemented by the new w9xpopen.exe helper in the root of your
3524Python installation. Note that Python uses this internally; it is not
3525a standalone program.
3526
3527Administrator privileges are no longer required to install Python
3528on Windows NT or Windows 2000. If you have administrator privileges,
3529Python's registry info will be written under HKEY_LOCAL_MACHINE.
3530Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003531under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003532uses of Python, but will prevent some advanced uses from working
3533(for example, running a Python script as an NT service, or possibly
3534from CGI).
3535
3536[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3537installer; instead, it installs the needed Tcl/Tk files directly in the
3538Python directory. If you already have a Tcl/Tk installation, this
3539wastes some disk space (about 4 Megs) but avoids problems with
3540conflicting Tcl/Tk installations, and makes it much easier for Python
3541to ensure that Tcl/Tk can find all its files.
3542
3543[This was new in 1.6] The Windows installer now installs by default in
3544\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3545
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003546
3547Updates to the changes between 1.5.2 and 1.6
3548--------------------------------------------
3549
3550The 1.6 NEWS file can't be changed after the release is done, so here
3551is some late-breaking news:
3552
3553New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3554and changes to getlocale() and setlocale().
3555
3556The new module is now enabled per default.
3557
3558It is not true that the encodings codecs cannot be used for normal
3559strings: the string.encode() (which is also present on 8-bit strings
3560!) allows using them for 8-bit strings too, e.g. to convert files from
3561cp1252 (Windows) to latin-1 or vice-versa.
3562
3563Japanese codecs are available from Tamito KAJIYAMA:
3564http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3565
3566
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003567======================================================================