blob: 2d323eabcb549949f83330c76e681a701540e93c [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
Raymond Hettinger5a04aec2002-06-25 00:25:30 +00009- Slices and repetitions of buffer objects now consistently return
10 a string. Formerly, strings would be returned most of the time,
11 but a buffer object would be returned when the repetition count
12 was one or when the slice range was all inclusive.
13
Guido van Rossumc7c36502002-06-21 01:29:25 +000014- The __slots__ variable can now mention "private" names, and the
15 right thing will happen (e.g. __slots__ = ["__foo"]).
16
Walter Dörwald3430d702002-06-17 10:43:59 +000017- Unicode objects in sys.path are no longer ignored but treated
18 as directory names.
19
Guido van Rossum9562bcf2002-06-14 21:31:18 +000020- The built-ins slice() and buffer() are now callable types. The
21 types classobj (formerly class), code, function, instance, and
22 instancemethod (formerly instance-method), which have no built-in
23 names but are accessible through the types module, are now also
24 callable. The type dict-proxy is renamed to dictproxy.
25
Neal Norwitz1f68fc72002-06-14 00:50:42 +000026- Fixed string.startswith and string.endswith builtin methods
27 so they accept negative indices. [SF bug 493951]
28
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000029- Fixed a bug with a continue inside a try block and a yield in the
30 finally clause. [SF bug 567538]
31
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000032- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000033 with a third "stride" parameter. For example, "hello world"[::-1]
34 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000035
Guido van Rossum9f7549b2002-06-10 21:39:42 +000036- Cycles going through the __class__ link of a new-style instance are
37 now detected by the garbage collector.
38
Guido van Rossum9923ffe2002-06-04 19:52:53 +000039- Classes using __slots__ are now properly garbage collected.
40 [SF bug 519621]
41
42- Tightened the __slots__ rules: a slot name must be a valid Python
43 identifier.
44
Guido van Rossum2e4e0262002-06-04 05:58:34 +000045- The constructor for the module type now requires a name argument and
46 takes an optional docstring argument. Previously, this constructor
47 ignored its arguments. As a consequence, deriving a class from a
48 module (not from the module type) is now illegal; previously this
49 created an unnamed module, just like invoking the module type did.
50 [SF bug 563060]
51
Neal Norwitzd68f5172002-05-29 15:54:55 +000052- A new warning PendingDeprecationWarning was added to provide
53 direction on features which are in the process of being deprecated.
54 The warning will not be printed by default. To see the pending
55 deprecations, use -Walways::PendingDeprecationWarning::
56 as a command line option or warnings.filterwarnings() in code.
57
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000058- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000059 for 'str' and 'unicode', and can be used instead of
60 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000061 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000062 is an abstract base class and cannot be instantiated directly.
63
Fred Draked0ba6362002-05-02 21:28:26 +000064- Deprecated features of xrange objects have been removed as
65 promised. The start, stop, and step attributes and the tolist()
66 method no longer exist. xrange repetition and slicing have been
67 removed.
68
Guido van Rossum7dab2422002-04-26 19:40:56 +000069- New builtin function enumerate(x), from PEP 279. Example:
70 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
71 The argument can be an arbitrary iterable object.
72
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000073- The assert statement no longer tests __debug__ at runtime. This means
74 that assert statements cannot be disabled by assigning a false value
75 to __debug__.
76
Walter Dörwald068325e2002-04-15 13:36:47 +000077- A method zfill() was added to str and unicode, that fills a numeric
78 string to the left with zeros. For example,
79 "+123".zfill(6) -> "+00123".
80
Guido van Rossum862fe3c2002-04-15 12:36:47 +000081- Complex numbers supported divmod() and the // and % operators, but
82 these make no sense. Since this was documented, they're being
83 deprecated now.
84
Guido van Rossum26dd8302002-04-26 20:11:29 +000085- String and unicode methods lstrip(), rstrip() and strip() now take
86 an optional argument that specifies the characters to strip. For
87 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000088
Guido van Rossumc69343b2002-04-12 19:22:48 +000089- Added a new dict method pop(key). This removes and returns the
90 value corresponding to key. [SF patch #539949]
91
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000092- Changed new-style class instantiation so that when C's __new__
93 method returns something that's not a C instance, its __init__ is
94 not called. [SF bug #537450]
95
Guido van Rossum181e41a2002-04-06 00:23:25 +000096- Fixed super() to work correctly with class methods. [SF bug #535444]
97
Guido van Rossum47834462002-04-04 15:21:33 +000098- A new built-in type, bool, has been added, as well as built-in
99 names for its two values, True and False. Comparisons and sundry
100 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000101 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000102 is backward compatible.
103
Guido van Rossum95b62a62002-03-29 01:07:24 +0000104- Fixed two bugs reported as SF #535905: under certain conditions,
105 deallocating a deeply nested structure could cause a segfault in the
106 garbage collector, due to interaction with the "trashcan" code;
107 access to the current frame during destruction of a local variable
108 could access a pointer to freed memory.
109
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000110- The optional object allocator ("pymalloc") has been enabled by
111 default. The recommended practice for memory allocation and
112 deallocation has been streamlined. A header file is included,
113 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
114 and lets them use the same API with Python versions from 1.5.2
115 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000116
Guido van Rossum8c842552002-03-14 23:05:54 +0000117- If you try to pickle an instance of a class that has __slots__ but
118 doesn't define or override __getstate__, a TypeError is now raised.
119 This is done by adding a bozo __getstate__ to the class that always
120 raises TypeError. (Before, this would appear to be pickled, but the
121 state of the slots would be lost.)
122
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000123- PyErr_Display will provide file and line information for all exceptions
124 that have an attribute print_file_and_line, not just SyntaxErrors.
125
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000126- The UTF-8 codec will now encode and decode Unicode surrogates
127 correctly and without raising exceptions for unpaired ones.
128
Neal Norwitz649b7592002-01-01 19:07:13 +0000129- file.xreadlines() now raises a ValueError if the file is closed:
130 Previously, an xreadlines object was returned which would raise
131 a ValueError when the xreadlines.next() method was called.
132
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000133- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000134 An exception will now be raised if more than one argument is used.
135
Tim Petersaf8446f2001-12-21 21:36:50 +0000136Extension modules
137
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000138- The 'new' module is no longer an extension, but a Python module that
139 only exists for backwards compatibility. Its contents are no longer
140 functions but callable type objects.
141
Tim Peters81b92512002-04-29 01:37:32 +0000142- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000143 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000144 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000145
Martin v. Löwis606edc12002-06-13 21:09:11 +0000146- posix.killpg, posix.mknod, and posix.getpgid have been added where
147 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000148
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000149- The locale module now exposes the C library's gettext interface.
150
Tim Petersfbf74f22002-03-14 19:06:01 +0000151- A security hole ("double free") was found in zlib-1.1.3, a popular
152 third party compression library used by some Python modules. The
153 hole was quickly plugged in zlib-1.1.4, and the Windows build of
154 Python now ships with zlib-1.1.4.
155
Martin v. Löwis688357e2002-04-08 21:28:20 +0000156- pwd, grp, and resource return enhanced tuples now, with symbolic
157 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000158
Martin v. Löwis99866332002-03-01 10:27:01 +0000159- array.array is now a type object. A new format character
160 'u' indicates Py_UNICODE arrays. For those, .tounicode and
161 .fromunicode methods are available. Arrays now support __iadd__
162 and __imul__.
163
Neal Norwitze790eae2002-01-01 21:14:12 +0000164- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000165 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
166 is called.
167
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000168- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
169 been added where available.
170
Tim Petersaf8446f2001-12-21 21:36:50 +0000171Library
172
Tim Peters943382c2002-07-07 03:59:34 +0000173- binascii.crc32() and the zipfile module had problems on some 64-bit
174 platforms. These have been fixed. On a platform with 8-byte C longs,
175 crc32() now returns a signed-extended 4-byte result, so that its value
176 as a Python int is equal to the value computed a 32-bit platform.
177
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000178- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
179 argument.
180
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000181- Some fixes in the copy module: when an object is copied through its
182 __reduce__ method, there was no check for a __setstate__ method on
183 the result [SF patch 565085]; deepcopy should treat instances of
184 custom metaclasses the same way it treats instances of type 'type'
185 [SF patch 560794].
186
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000187- Sockets now support timeout mode. After s.settimeout(T), where T is
188 a float expressing seconds, subsequent operations raise an exception
189 if they cannot be completed within T seconds. To disable timeout
190 mode, use s.settimeout(None).
191
192- getopt.gnu_getopt was added. This supports GNU-style option
193 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000194
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000195- Stop using strings for exceptions. String objects used for
196 exceptions are now classes deriving from Exception. The objects
197 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
198 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000199
Walter Dörwald474458d2002-06-04 15:16:29 +0000200- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
201 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
202 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
203 big endian systems were added to the codecs module. The old names
204 BOM32_* and BOM64_* were off by a factor of 2.
205
Guido van Rossumf9257822002-06-18 20:43:18 +0000206- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000207
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000208- ftplib.retrlines() now tests for callback is None rather than testing
209 for False. Was causing an error when given a callback object which
210 was callable but also returned len() as zero. The change may
211 create new breakage if the caller relied on the undocumented behavior
212 and called with callback set to [] or some other False value not
213 identical to None.
214
Tim Peters46c04e12002-05-05 20:40:00 +0000215- random.gauss() uses a piece of hidden state used by nothing else,
216 and the .seed() and .whseed() methods failed to reset it. In other
217 words, setting the seed didn't completely determine the sequence of
218 results produced by random.gauss(). It does now. Programs repeatedly
219 mixing calls to a seed method with calls to gauss() may see different
220 results now.
221
Fred Drake7f781c92002-05-01 20:33:53 +0000222- The pickle.Pickler class grew a clear_memo() method to mimic that
223 provided by cPickle.Pickler.
224
Tim Peters81b92512002-04-29 01:37:32 +0000225- difflib's SequenceMatcher class now does a dynamic analysis of
226 which elements are so frequent as to constitute noise. For
227 comparing files as sequences of lines, this generally works better
228 than the IS_LINE_JUNK function, and function ndiff's linejunk
229 argument defaults to None now as a result. A happy benefit is
230 that SequenceMatcher may run much faster now when applied
231 to large files with many duplicate lines (for example, C program
232 text with lots of repeated "}" and "return NULL;" lines).
233
Guido van Rossum256705b2002-04-23 13:29:43 +0000234- New Text.dump() method in Tkinter module.
235
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000236- New distutils commands for building packagers were added to
237 support pkgtool on Solaris and swinstall on HP-UX.
238
239- distutils now has a new abstract binary packager base class
240 command/bdist_packager, which simplifies writing packagers.
241 This will hopefully provide the missing bits to encourage
242 people to submit more packagers, e.g. for Debian, FreeBSD
243 and other systems.
244
Guido van Rossumf9257822002-06-18 20:43:18 +0000245- The UTF-16, -LE and -BE stream readers now raise a
246 NotImplementedError for all calls to .readline(). Previously, they
247 used to just produce garbage or fail with an encoding error --
248 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 +0000249 work well with these.
250
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000251- compileall now supports quiet operation.
252
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000253- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000254 connections.
255
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000256- socket module: the SSL support was broken out of the main
257 _socket module C helper and placed into a new _ssl helper
258 which now gets imported by socket.py if available and working.
259
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000260- encodings package: added aliases for all supported IANA character
261 sets
262
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000263- ftplib: to safeguard the user's privacy, anonymous login will use
264 "anonymous@" as default password, rather than the real user and host
265 name.
266
Fred Drake36736122002-01-10 13:50:31 +0000267- webbrowser: tightened up the command passed to os.system() so that
268 arbitrary shell code can't be executed because a bogus URL was
269 passed in.
270
Tim Peters11bd9942002-02-01 00:52:29 +0000271- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000272 gettext.find an optional all argument. Translations will now fallback
273 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000274
Martin v. Löwis9668b932002-01-12 11:27:42 +0000275- distutils bdist commands now offer a --skip-build option.
276
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000277- warnings.warn now accepts a Warning instance as first argument.
278
Fred Drakefed7e852002-04-04 19:36:15 +0000279- The xml.sax.expatreader.ExpatParser class will no longer create
280 circular references by using itself as the locator that gets passed
281 to the content handler implementation. [SF bug #535474]
282
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000283- The email.Parser.Parser class now properly parses strings regardless
284 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
285 or CRLF). Also, the Header class's constructor default arguments
286 has changed slightly so that an explicit maxlinelen value is always
287 honored.
288
Tim Petersaf8446f2001-12-21 21:36:50 +0000289Tools/Demos
290
Marc-André Lemburg46260092002-04-04 16:17:11 +0000291- freeze.py now produces binaries which can import shared modules,
292 unlike before when this failed due to missing symbol exports in
293 the generated binary.
294
Tim Petersaf8446f2001-12-21 21:36:50 +0000295Build
296
Tim Peters943382c2002-07-07 03:59:34 +0000297- Compiling out the cyclic garbage collector is no longer an option.
298 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
299 that it's always defined (for the benefit of any extension modules
300 that may be conditionalizing on it). A bonus is that any extension
301 type participating in cyclic gc can choose to participate in the
302 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
303 to require editing the core to teach the trashcan mechanism about the
304 new type.
305
Tim Peters1de41bf2002-07-03 03:31:20 +0000306- Accoring to Annex F of the current C standard,
307
308 The Standard C macro HUGE_VAL and its float and long double analogs,
309 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
310 positive infinities.
311
312 Python only uses the double HUGE_VAL, and only to #define its own symbol
313 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
314 pyport.h used to try to worm around that, but the workarounds triggered
315 other bugs on other platforms, so we gave up. If your platform defines
316 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
317 that works on your platform. The only instance of this I'm sure about
318 is on an unknown subset of Cray systems, described here:
319
320 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
321
322 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
323
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000324- The configure option --without-doc-strings can be used to remove the
325 doc strings from the builtin functions and modules; this reduces the
326 size of the executable.
327
Tim Peters639295f2002-04-21 07:30:30 +0000328- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
329 say how or when to configure it, or how to turn it off.
330
Martin v. Löwis1142de32002-03-29 16:28:31 +0000331- On Unix, a shared libpython2.3.so can be created with --enable-shared.
332
Tim Peters8deda702002-03-30 10:06:07 +0000333- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
334 preprocessor symbols were eliminated. The internal decisions they
335 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000336
Fred Drake7d28b732002-05-02 21:17:00 +0000337- The tools used to build the documentation now work under Cygwin as
338 well as Unix.
339
Skip Montanaro57454e52002-06-14 20:30:31 +0000340- The bsddb and dbm module builds have been changed to try and avoid version
341 skew problems and disable linkage with Berkeley DB 1.85 unless the
342 installer knows what s/he's doing. See the section on building these
343 modules in the README file for details.
344
Tim Petersaf8446f2001-12-21 21:36:50 +0000345C API
346
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000347- Added new macro PySequence_ITEM(o, i) that directly calls
348 sq_item without rechecking that o is a sequence and without
349 adjusting for negative indices.
350
Fred Draked0ba6362002-05-02 21:28:26 +0000351- PyRange_New() now raises ValueError if the fourth argument is not 1.
352 This is part of the removal of deprecated features of the xrange
353 object.
354
Guido van Rossum517c7d42002-04-26 02:49:14 +0000355- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
356 coercion if both arguments have the same type but this type has the
357 CHECKTYPES flag set. This is to better support proxies.
358
Neil Schemenauer9344b142002-04-12 23:00:08 +0000359- The type of tp_free has been changed from "void (*)(PyObject *)" to
360 "void (*)(void *)".
361
362- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
363
Guido van Rossum0986d822002-04-08 01:38:42 +0000364- A type can now inherit its metatype from its base type. Previously,
365 when PyType_Ready() was called, if ob_type was found to be NULL, it
366 was always set to &PyType_Type; now it is set to base->ob_type,
367 where base is tp_base, defaulting to &PyObject_Type.
368
369- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
370
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000371- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000372
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000373- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000374 without going through the buffer API.
375
Martin v. Löwis7198a522002-01-01 19:59:11 +0000376- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
377
Tim Peters10a3bb52001-12-25 19:07:38 +0000378- An old #define of ANY as void has been removed from pyport.h. This
379 hasn't been used since Python's pre-ANSI days, and the #define has
380 been marked as obsolete since then. SF bug 495548 says it created
381 conflicts with other packages, so keeping it around wasn't harmless.
382
Tim Petersaf8446f2001-12-21 21:36:50 +0000383- Because Python's magic number scheme broke on January 1st, we decided
384 to stop Python development. Thanks for all the fish!
385
Tim Petersfb05db22002-03-11 00:24:00 +0000386- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000387 scheme to a new one. See Python/import.c for details.
388
Tim Petersaf8446f2001-12-21 21:36:50 +0000389New platforms
390
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000391- AtheOS is now supported.
392
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000393- GNU/Hurd is now supported.
394
Tim Petersaf8446f2001-12-21 21:36:50 +0000395Tests
396
397Windows
398
Tim Peters08e72952002-04-16 20:48:01 +0000399- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
400 of that has been fixed in the installer (disabled Wise's "delete in-
401 use files" uninstall option).
402
Guido van Rossum181e41a2002-04-06 00:23:25 +0000403- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
404
Tim Peters33187922002-04-04 20:02:04 +0000405- The installer now installs Start menu shortcuts under (the local
406 equivalent of) "All Users" when doing an Admin install.
407
Tim Petersfb05db22002-03-11 00:24:00 +0000408- file.truncate([newsize]) now works on Windows for all newsize values.
409 It used to fail if newsize didn't fit in 32 bits, reflecting a
410 limitation of MS _chsize (which is no longer used).
411
Tim Petersab034fa2002-02-01 11:27:43 +0000412- os.waitpid() is now implemented for Windows, and can be used to block
413 until a specified process exits. This is similar to, but not exactly
414 the same as, os.waitpid() on POSIX systems. If you're waiting for
415 a specific process whose pid was obtained from one of the spawn()
416 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000417 See the docs for details. The docs were changed to clarify that
418 spawn functions return, and waitpid requires, a process handle on
419 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000420
Tim Peters11bd9942002-02-01 00:52:29 +0000421- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000422 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000423 to a nasty problem: before 2.3, if you got a temp file on Windows, it
424 got wrapped in an object whose close() method first closed the
425 underlying file, then deleted the file. This usually worked fine.
426 However, the spawn family of functions on Windows create (at a low C
427 level) the same set of open files in the spawned process Q as were
428 open in the spawning process P. If a temp file f was among them, then
429 doing f.close() in P first closed P's C-level file handle on f, but Q's
430 C-level file handle on f remained open, so the attempt in P to delete f
431 blew up with a "Permission denied" error (Windows doesn't allow
432 deleting open files). This was surprising, subtle, and difficult to
433 work around.
434
435- The os module now exports all the symbolic constants usable with the
436 low-level os.open() on Windows: the new constants in 2.3 are
437 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
438 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
439 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
440 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
441 (so specify both if you want both; note that neither is useful unless
442 specified with O_CREAT too).
443
Tim Petersaf8446f2001-12-21 21:36:50 +0000444Mac
445
446
Tim Peters909c0912001-12-14 23:16:18 +0000447What's New in Python 2.2 final?
448Release date: 21-Dec-2001
449===============================
450
451Type/class unification and new-style classes
452
Barry Warsaw52acb492001-12-21 20:04:22 +0000453- pickle.py, cPickle: allow pickling instances of new-style classes
454 with a custom metaclass.
455
Tim Peters909c0912001-12-14 23:16:18 +0000456Core and builtins
457
Barry Warsaw52acb492001-12-21 20:04:22 +0000458- weakref proxy object: when comparing, unwrap both arguments if both
459 are proxies.
460
Tim Peters909c0912001-12-14 23:16:18 +0000461Extension modules
462
Barry Warsaw52acb492001-12-21 20:04:22 +0000463- binascii.b2a_base64(): fix a potential buffer overrun when encoding
464 very short strings.
465
466- cPickle: the obscure "fast" mode was suspected of causing stack
467 overflows on the Mac. Hopefully fixed this by setting the recursion
468 limit much smaller. If the limit is too low (it only affects
469 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
470 when compiling cPickle.c (or in pyconfig.h).
471
Tim Peters909c0912001-12-14 23:16:18 +0000472Library
473
Barry Warsaw52acb492001-12-21 20:04:22 +0000474- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
475 close or delete time).
476
477- rfc822.py: fixed a bug where the address '<>' was converted to None
478 instead of an empty string (also fixes the email.Utils module).
479
480- xmlrpclib.py: version 1.0.0; uses precision for doubles.
481
482- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000483 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000484
Tim Peters909c0912001-12-14 23:16:18 +0000485Tools/Demos
486
487Build
488
489C API
490
491New platforms
492
493Tests
494
495Windows
496
Barry Warsaw52acb492001-12-21 20:04:22 +0000497- distutils package: fixed broken Windows installers (bdist_wininst).
498
499- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
500 instances are deleted at process exit time.
501
502- socket.py: prevent mysterious warnings when socket instances are
503 deleted at process exit time.
504
505- posixmodule.c: fix a Windows crash with stat() of a filename ending
506 in backslash.
507
Tim Peters909c0912001-12-14 23:16:18 +0000508Mac
509
Barry Warsaw52acb492001-12-21 20:04:22 +0000510- The Carbon toolbox modules have been upgraded to Universal Headers
511 3.4, and experimental CoreGraphics and CarbonEvents modules have
512 been added. All only for framework-enabled MacOSX.
513
Tim Peters909c0912001-12-14 23:16:18 +0000514
Tim Peters6272dfd2001-12-13 19:34:00 +0000515What's New in Python 2.2c1?
516Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000517===========================
518
519Type/class unification and new-style classes
520
Barry Warsaw06557452001-12-14 20:47:12 +0000521- Guido's tutorial introduction to the new type/class features has
522 been extensively updated. See
523
524 http://www.python.org/2.2/descrintro.html
525
526 That remains the primary documentation in this area.
527
Guido van Rossum33bab012001-12-05 22:45:48 +0000528- Fixed a leak: instance variables declared with __slots__ were never
529 deleted!
530
Guido van Rossum4b800852001-12-03 00:54:52 +0000531- The "delete attribute" method of descriptor objects is called
532 __delete__, not __del__. In previous releases, it was mistakenly
533 called __del__, which created an unfortunate overloading condition
534 with finalizers. (The "get attribute" and "set attribute" methods
535 are still called __get__ and __set__, respectively.)
536
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000537- Some subtle issues with the super built-in were fixed:
538
539 (a) When super itself is subclassed, its __get__ method would still
540 return an instance of the base class (i.e., of super).
541
542 (b) super(C, C()).__class__ would return C rather than super. This
543 is confusing. To fix this, I decided to change the semantics of
544 super so that it only applies to code attributes, not to data
545 attributes. After all, overriding data attributes is not
546 supported anyway.
547
548 (c) The __get__ method didn't check whether the argument was an
549 instance of the type used in creation of the super instance.
550
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000551- Previously, hash() of an instance of a subclass of a mutable type
552 (list or dictionary) would return some value, rather than raising
553 TypeError. This has been fixed. Also, directly calling
554 dict.__hash__ and list.__hash__ now raises the same TypeError
555 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000556
Guido van Rossumd331cb52001-12-05 19:46:42 +0000557- New-style objects now support deleting their __dict__. This is for
558 all intents and purposes equivalent to assigning a brand new empty
559 dictionary, but saves space if the object is not used further.
560
Tim Petersb3c9af12001-11-17 00:21:57 +0000561Core and builtins
562
Tim Peters3caca232001-12-06 06:23:26 +0000563- -Qnew now works as documented in PEP 238: when -Qnew is passed on
564 the command line, all occurrences of "/" use true division instead
565 of classic division. See the PEP for details. Note that "all"
566 means all instances in library and 3rd-party modules, as well as in
567 your own code. As the PEP says, -Qnew is intended for use only in
568 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000569 Note that test_coercion.py in the standard Python test suite fails
570 under -Qnew; this is expected, and won't be repaired until true
571 division becomes the default (in the meantime, test_coercion is
572 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000573
Fred Drake6c01e252001-12-14 17:08:12 +0000574- complex() now only allows the first argument to be a string
575 argument, and raises TypeError if either the second arg is a string
576 or if the second arg is specified when the first is a string.
577
Tim Petersb3c9af12001-11-17 00:21:57 +0000578Extension modules
579
Martin v. Löwis560da622001-11-24 09:24:51 +0000580- gc.get_referents was renamed to gc.get_referrers.
581
Tim Petersb3c9af12001-11-17 00:21:57 +0000582Library
583
Tim Peters25059d32001-12-07 20:35:43 +0000584- Functions in the os.spawn() family now release the global interpreter
585 lock around calling the platform spawn. They should always have done
586 this, but did not before 2.2c1. Multithreaded programs calling
587 an os.spawn function with P_WAIT will no longer block all Python threads
588 until the spawned program completes. It's possible that some programs
589 relies on blocking, although more likely by accident than by design.
590
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000591- webbrowser defaults to netscape.exe on OS/2 now.
592
Martin v. Löwis652e1912001-11-25 14:50:56 +0000593- Tix.ResizeHandle exposes detach_widget, hide, and show.
594
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000595- The charset alias windows_1252 has been added.
596
Barry Warsaw06557452001-12-14 20:47:12 +0000597- types.StringTypes is a tuple containing the defined string types;
598 usually this will be (str, unicode), but if Python was compiled
599 without Unicode support it will be just (str,).
600
601- The pulldom and minidom modules were synchronized to PyXML.
602
Tim Petersb3c9af12001-11-17 00:21:57 +0000603Tools/Demos
604
Barry Warsaw06557452001-12-14 20:47:12 +0000605- A new script called Tools/scripts/google.py was added, which fires
606 off a search on Google.
607
Tim Petersb3c9af12001-11-17 00:21:57 +0000608Build
609
Barry Warsaw06557452001-12-14 20:47:12 +0000610- Note that release builds of Python should arrange to define the
611 preprocessor symbol NDEBUG on the command line (or equivalent).
612 In the 2.2 pre-release series we tried to define this by magic in
613 Python.h instead, but it proved to cause problems for extension
614 authors. The Unix, Windows and Mac builds now all define NDEBUG in
615 release builds via cmdline (or equivalent) instead. Ports to
616 other platforms should do likewise.
617
Jack Jansen1999ef42001-12-06 21:47:20 +0000618- It is no longer necessary to use --with-suffix when building on a
619 case-insensitive file system (such as Mac OS X HFS+). In the build
620 directory an extension is used, but not in the installed python.
621
Tim Petersb3c9af12001-11-17 00:21:57 +0000622C API
623
Tim Petersf582b822001-12-11 18:51:08 +0000624- New function PyDict_MergeFromSeq2() exposes the builtin dict
625 constructor's logic for updating a dictionary from an iterable object
626 producing key-value pairs.
627
Tim Peterscffed4b2001-11-29 03:26:37 +0000628- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000629 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000630 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
631 dump core in some bad cases. This has been repaired. As a result,
632 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
633 previously went unchallenged.
634
Tim Petersb3c9af12001-11-17 00:21:57 +0000635New platforms
636
637Tests
638
639Windows
640
641Mac
642
Jack Jansenffa260f2001-12-06 21:14:00 +0000643- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
644 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000645
Barry Warsaw06557452001-12-14 20:47:12 +0000646- Changed logic for finding python home in Mac OS X framework Pythons.
647 Now sys.executable points to the executable again, in stead of to
648 the shared library. The latter is used only for locating the python
649 home.
650
651
Tim Peters84362bc2001-10-19 17:55:30 +0000652What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000653Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000654===========================
655
656Type/class unification and new-style classes
657
Guido van Rossum3d27df02001-11-15 20:27:54 +0000658- Multiple inheritance mixing new-style and classic classes in the
659 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000660
661 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000662 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000663
664 The MRO (method resolution order) for each base class is respected
665 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000666 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000667 This needs to be documented.
668
Tim Petersa427a2b2001-10-29 22:25:45 +0000669- The new builtin dictionary() constructor, and dictionary type, have
670 been renamed to dict. This reflects a decade of common usage.
671
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000672- dict() now accepts an iterable object producing 2-sequences. For
673 example, dict(d.items()) == d for any dictionary d. The argument,
674 and the elements of the argument, can be any iterable objects.
675
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000676- New-style classes can now have a __del__ method, which is called
677 when the instance is deleted (just like for classic classes).
678
Guido van Rossum12d955c2001-10-26 14:56:06 +0000679- Assignment to object.__dict__ is now possible, for objects that are
680 instances of new-style classes that have a __dict__ (unless the base
681 class forbids it).
682
Guido van Rossumc8e56452001-10-22 00:43:43 +0000683- Methods of built-in types now properly check for keyword arguments
684 (formerly these were silently ignored). The only built-in methods
685 that take keyword arguments are __call__, __init__ and __new__.
686
Guido van Rossum86443212001-10-27 22:28:54 +0000687- The socket function has been converted to a type; see below.
688
Tim Peters84362bc2001-10-19 17:55:30 +0000689Core and builtins
690
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000691- Assignment to __debug__ raises SyntaxError at compile-time. This
692 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000693 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000694
Guido van Rossum12d955c2001-10-26 14:56:06 +0000695- Clarified the error messages for unsupported operands to an operator
696 (like 1 + '').
697
Tim Peters84362bc2001-10-19 17:55:30 +0000698Extension modules
699
Tim Peters5ebfd362001-11-13 23:11:19 +0000700- mmap has a new keyword argument, "access", allowing a uniform way for
701 both Windows and Unix users to create read-only, write-through and
702 copy-on-write memory mappings. This was previously possible only on
703 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000704 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000705 platforms. Thanks to Jay T Miller for repairing this!
706
Tim Peters169ded02001-11-03 19:57:21 +0000707- By default, the gc.garbage list now contains only those instances in
708 unreachable cycles that have __del__ methods; in 2.1 it contained all
709 instances in unreachable cycles. "Instances" here has been generalized
710 to include instances of both new-style and old-style classes.
711
Guido van Rossum12d955c2001-10-26 14:56:06 +0000712- The socket module defines a new method for socket objects,
713 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000714 send() until all data has been sent. Also, the socket function has
715 been converted to a subclassable type, like list and tuple (etc.)
716 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000717
718- Various bugfixes to the curses module. There is now a test suite
719 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000720
Guido van Rossum692adf12001-10-30 03:03:03 +0000721- binascii.b2a_base64 no longer places an arbitrary restriction of 57
722 bytes on its input.
723
Tim Peters84362bc2001-10-19 17:55:30 +0000724Library
725
Tim Peters5ebfd362001-11-13 23:11:19 +0000726- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000727 convenience function.
728
Tim Peters75335872001-11-03 19:35:43 +0000729- Symbolic group names in regular expressions must be unique. For
730 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
731 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000732 Python 2.2 detects this error at regexp compilation time;
733 previously, the error went undetected, and results were
734 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
735 pattern.subn() methods have been rewritten in C. Also, an
736 experimental function/method finditer() has been added, which works
737 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000738
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000739- Tix exposes more commands through the classes DirSelectBox,
740 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
741 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
742 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
743
Tim Peters98791af2001-10-23 01:59:54 +0000744- Traceback objects are now scanned by cyclic garbage collection, so
745 cycles created by casual use of sys.exc_info() no longer cause
746 permanent memory leaks (provided garbage collection is enabled).
747
Guido van Rossum49192142001-10-24 20:51:44 +0000748- os.extsep -- a new variable needed by the RISCOS support. It is the
749 separator used by extensions, and is '.' on all platforms except
750 RISCOS, where it is '/'. There is no need to use this variable
751 unless you have a masochistic desire to port your code to RISCOS.
752
Barry Warsaw012852b2001-11-16 16:17:27 +0000753- mimetypes.py has optional support for non-standard, but commonly
754 found types. guess_type() and guess_extension() now accept an
755 optional `strict' flag, defaulting to true, which controls whether
756 recognize non-standard types or not. A few non-standard types we
757 know about have been added. Also, when run as a script, there are
758 new -l and -e options.
759
760- statcache is now deprecated.
761
762- email.Utils.formatdate() now produces the preferred RFC 2822 style
763 dates with numeric timezones (it used to produce obsolete dates
764 hard coded to "GMT" timezone). An optional `localtime' flag is
765 added to produce dates in the local timezone, with daylight savings
766 time properly taken into account.
767
768- In pickle and cPickle, instead of masking errors in load() by
769 transforming them into SystemError, we let the original exception
770 propagate out. Also, implement support for __safe_for_unpickling__
771 in pickle, as it already was supported in cPickle.
772
Tim Peters84362bc2001-10-19 17:55:30 +0000773Tools/Demos
774
775Build
776
Barry Warsaw012852b2001-11-16 16:17:27 +0000777- The dbm module is built using libdb1 if available. The bsddb module
778 is built with libdb3 if available.
779
780- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
781
Tim Peters84362bc2001-10-19 17:55:30 +0000782C API
783
Tim Peters1fc240e2001-10-26 05:06:50 +0000784- New function PySequence_Fast_GET_SIZE() returns the size of a non-
785 NULL result from PySequence_Fast(), more quickly than calling
786 PySequence_Size().
787
Barry Warsaw012852b2001-11-16 16:17:27 +0000788- New argument unpacking function PyArg_UnpackTuple() added.
789
790- New functions PyObject_CallFunctionObjArgs() and
791 PyObject_CallMethodObjArgs() have been added to make it more
792 convenient and efficient to call functions and methods from C.
793
794- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
795 possible that this will propagate errors it didn't before.
796
797- New function PyObject_CheckReadBuffer(), which returns true if its
798 argument supports the single-segment readable buffer interface.
799
Tim Peters84362bc2001-10-19 17:55:30 +0000800New platforms
801
Guido van Rossum86443212001-10-27 22:28:54 +0000802- We've finally confirmed that this release builds on HP-UX 11.00,
803 *with* threads, and passes the test suite.
804
Tim Peters7a33d8b2001-11-05 02:51:07 +0000805- Thanks to a series of patches from Michael Muller, Python may build
806 again under OS/2 Visual Age C++.
807
Guido van Rossum49192142001-10-24 20:51:44 +0000808- Updated RISCOS port by Dietmar Schwertberger.
809
Tim Peters84362bc2001-10-19 17:55:30 +0000810Tests
811
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000812- Added a test script for the curses module. It isn't run automatically;
813 regrtest.py must be run with '-u curses' to enable it.
814
Tim Peters84362bc2001-10-19 17:55:30 +0000815Windows
816
Barry Warsaw012852b2001-11-16 16:17:27 +0000817Mac
818
819- PythonScript has been moved to unsupported and is slated to be
820 removed completely in the next release.
821
822- It should now be possible to build applets that work on both OS9 and
823 OSX.
824
825- The core is now linked with CoreServices not Carbon; as a side
826 result, default 8bit encoding on OSX is now ASCII.
827
828- Python should now build on OSX 10.1.1
829
Tim Peters84362bc2001-10-19 17:55:30 +0000830
Tim Petersabf925f2001-09-28 21:53:42 +0000831What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000832Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000833===========================
834
835Type/class unification and new-style classes
836
Guido van Rossum687ae002001-10-15 22:03:32 +0000837- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000838 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000839 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000840 remains: the __dict__ of a new-style class is a read-only proxy; you
841 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000842 __defined__ attribute of new-style types no longer exists, for lack
843 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000844 future a __cache__ may be resurrected with a similar function, if I
845 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000846
Tim Peters1c9ca872001-10-04 06:43:12 +0000847- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
848 always returned None, even when there was a class docstring).
849
850- doctest now finds and runs docstrings attached to new-style classes,
851 class methods, static methods, and properties.
852
Guido van Rossum9074ef62001-10-16 21:34:49 +0000853Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000854
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000855- A very subtle syntactical pitfall in list comprehensions was fixed.
856 For example: [a+b for a in 'abc', for b in 'def']. The comma in
857 this example is a mistake. Previously, this would silently let 'a'
858 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
859 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
860 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
861 Note that [a for a in <singleton>] is a convoluted way to say
862 [<singleton>] anyway, so it's not like any expressiveness is lost.
863
Guido van Rossum9074ef62001-10-16 21:34:49 +0000864- getattr(obj, name, default) now only catches AttributeError, as
865 documented, rather than returning the default value for all
866 exceptions (which could mask bugs in a __getattr__ hook, for
867 example).
868
Fred Drakecb7a6b52001-10-22 18:41:51 +0000869- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000870 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000871 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000872 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000873
Guido van Rossum1c486092001-10-19 02:05:35 +0000874- unicode(obj) now behaves more like str(obj), accepting arbitrary
875 objects, and calling a __unicode__ method if it exists.
876 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000877 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000878
Barry Warsawf6fb1712001-10-19 05:35:40 +0000879- isinstance() now allows any object as the first argument and a
880 class, a type or something with a __bases__ tuple attribute for the
881 second argument. The second argument may also be a tuple of a
882 class, type, or something with __bases__, in which case isinstance()
883 will return true if the first argument is an instance of any of the
884 things contained in the second argument tuple. E.g.
885
886 isinstance(x, (A, B))
887
888 returns true if x is an instance of A or B.
889
Guido van Rossum9074ef62001-10-16 21:34:49 +0000890Extension modules
891
892- thread.start_new_thread() now returns the thread ID (previously None).
893
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000894- binascii has now two quopri support functions, a2b_qp and b2a_qp.
895
Guido van Rossumc524d952001-10-19 01:31:59 +0000896- readline now supports setting the startup_hook and the
897 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000898
Guido van Rossumc524d952001-10-19 01:31:59 +0000899- os and posix supports chroot(), setgroups() and unsetenv() where
900 available. The stat(), fstat(), statvfs() and fstatvfs() functions
901 now return "pseudo-sequences" -- the various fields can now be
902 accessed as attributes (e.g. os.stat("/").st_mtime) but for
903 backwards compatibility they also behave as a fixed-length sequence.
904 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000905 attributes.
906
907- time: localtime(), gmtime() and strptime() now return a
908 pseudo-sequence similar to the os.stat() return value, with
909 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000910
Guido van Rossum9074ef62001-10-16 21:34:49 +0000911- Decompression objects in the zlib module now accept an optional
912 second parameter to decompress() that specifies the maximum amount
913 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000914
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000915- optional SSL support in the socket module now exports OpenSSL
916 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
917 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000918 automatically seed its PRNG. Also, the keyfile and certfile
919 arguments to socket.ssl() are now optional.
920
921- posixmodule (and by extension, the os module on POSIX platforms) now
922 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000923
Guido van Rossum9074ef62001-10-16 21:34:49 +0000924Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000925
Tim Peters7402f792001-10-02 03:53:41 +0000926- doctest now excludes functions and classes not defined by the module
927 being tested, thanks to Tim Hochberg.
928
Fred Drakecb7a6b52001-10-22 18:41:51 +0000929- HotShot, a new profiler implemented using a C-based callback, has
930 been added. This substantially reduces the overhead of profiling,
931 but it is still quite preliminary. Support modules and
932 documentation will be added in upcoming releases (before 2.2 final).
933
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000934- profile now produces correct output in situations where an exception
935 raised in Python is cleared by C code (e.g. hasattr()). This used
936 to cause wrong output, including spurious claims of recursive
937 functions and attribution of time spent to the wrong function.
938
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000939 The code and documentation for the derived OldProfile and HotProfile
940 profiling classes was removed. The code hasn't worked for years (if
941 you tried to use them, they raised exceptions). OldProfile
942 intended to reproduce the behavior of the profiler Python used more
943 than 7 years ago, and isn't interesting anymore. HotProfile intended
944 to provide a faster profiler (but producing less information), and
945 that's a worthy goal we intend to meet via a different approach (but
946 without losing information).
947
Tim Peterscce092d2001-10-09 05:31:56 +0000948- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000949 a much better system-specific calibration constant. The constant can
950 now be specified in an instance constructor, or as a Profile class or
951 instance variable, instead of by editing profile.py's source code.
952 Calibration must still be done manually (see the docs for the profile
953 module).
954
955 Note that Profile.calibrate() must be overriden by subclasses.
956 Improving the accuracy required exploiting detailed knowledge of
957 profiler internals; the earlier method abstracted away the details
958 and measured a simplified model instead, but consequently computed
959 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000960
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000961- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000962 which indicates whether output is intended for the header 'Q'
963 encoding.
964
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000965- The SocketServer.ThreadingMixIn class now closes the request after
966 finish_request() returns. (Not when it errors out though.)
967
Barry Warsawf6fb1712001-10-19 05:35:40 +0000968- The nntplib module's NNTP.body() method has grown a `file' argument
969 to allow saving the message body to a file.
970
971- The email package has added a class email.Parser.HeaderParser which
972 only parses headers and does not recurse into the message's body.
973 Also, the module/class MIMEAudio has been added for representing
974 audio data (contributed by Anthony Baxter).
975
976- ftplib should be able to handle files > 2GB.
977
978- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
979 ON, and OFF.
980
Fred Drakecb7a6b52001-10-22 18:41:51 +0000981- xml.dom.minidom NodeList objects now support the length attribute
982 and item() method as required by the DOM specifications.
983
Guido van Rossumed554f62001-10-02 23:15:37 +0000984Tools/Demos
985
986- Demo/dns was removed. It no longer serves any purpose; a package
987 derived from it is now maintained by Anthony Baxter, see
988 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000989
Barry Warsawf6fb1712001-10-19 05:35:40 +0000990- The freeze tool has been made more robust, and two new options have
991 been added: -X and -E.
992
Tim Petersabf925f2001-09-28 21:53:42 +0000993Build
994
Barry Warsawf6fb1712001-10-19 05:35:40 +0000995- configure will use CXX in LINKCC if CXX is used to build main() and
996 the system requires to link a C++ main using the C++ compiler.
997
Tim Petersabf925f2001-09-28 21:53:42 +0000998C API
999
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001000- The documentation for the tp_compare slot is updated to require that
1001 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1002 not correct. This is not yet enforced but will be enforced in
1003 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1004 "NotImplemented". Right now, -1 should be used for an error return.
1005
Tim Petersd38b1c72001-09-30 05:09:37 +00001006- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1007 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1008 as long) arguments.
1009
Guido van Rossum3c288632001-10-16 21:13:49 +00001010- PyThread_start_new_thread() now returns a long int giving the thread
1011 ID, if one can be calculated; it returns -1 for error, 0 if no
1012 thread ID is calculated (this is an incompatible change, but only
1013 the thread module used this API). This code has only really been
1014 tested on Linux and Windows; other platforms please beware (and
1015 report any bugs or strange behavior).
1016
Guido van Rossum1c486092001-10-19 02:05:35 +00001017- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1018 input.
1019
Tim Petersabf925f2001-09-28 21:53:42 +00001020New platforms
1021
1022Tests
1023
1024Windows
1025
Tim Peters04cf1d32001-10-09 22:39:40 +00001026- Installer: If you install IDLE, and don't disable file-extension
1027 registration, a new "Edit with IDLE" context (right-click) menu entry
1028 is created for .py and .pyw files.
1029
Tim Peters1ce3cf72001-10-01 17:58:40 +00001030- The signal module now supports SIGBREAK on Windows, thanks to Steven
1031 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1032 action remains to call Win32 ExitProcess(). This can be changed via
1033 signal.signal(). For example:
1034
1035 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1036 # (SIGINT) behavior.
1037 import signal
1038 signal.signal(signal.SIGBREAK,
1039 signal.default_int_handler)
1040
1041 try:
1042 while 1:
1043 pass
1044 except KeyboardInterrupt:
1045 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1046 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1047 # program without the possibility for any Python-level cleanup).
1048 print "Clean exit"
1049
Tim Petersabf925f2001-09-28 21:53:42 +00001050
Tim Petersb07352e2001-09-08 01:25:47 +00001051What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001052Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001053===========================
1054
Guido van Rossum808eea72001-09-25 04:15:41 +00001055Type/class unification and new-style classes
1056
1057- pydoc and inspect are now aware of new-style classes;
1058 e.g. help(list) at the interactive prompt now shows proper
1059 documentation for all operations on list objects.
1060
1061- Applications using Jim Fulton's ExtensionClass module can now safely
1062 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1063 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1064 examples also work again. It is hoped that Gtk and Boost also work
1065 with 2.2a4 and beyond. (If you can confirm this, please write
1066 webmaster@python.org; if there are still problems, please open a bug
1067 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001068
Tim Peters66c1a522001-09-24 21:17:50 +00001069- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001070 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001071 in the constructed property object. fget, fset and fdel weren't
1072 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1073 associate a docstring with a property.
1074
Guido van Rossum808eea72001-09-25 04:15:41 +00001075- Comparison overloading is now more completely implemented. For
1076 example, a str subclass instance can properly be compared to a str
1077 instance, and it can properly overload comparison. Ditto for most
1078 other built-in object types.
1079
1080- The repr() of new-style classes has changed; instead of <type
1081 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1082 *except* for built-in types, which are still rendered as <type
1083 'Foo'> (to avoid upsetting existing code that might parse or
1084 otherwise rely on repr() of certain type objects).
1085
1086- The repr() of new-style objects is now always <Foo object at XXX>;
1087 previously, it was sometimes <Foo instance at XXX>.
1088
1089- For new-style classes, what was previously called __getattr__ is now
1090 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001091 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001092 one in classic classes is defined which is called only if regular
1093 attribute access raises AttributeError; to catch *all* attribute
1094 access, you can use __getattribute__ (for new-style classes). If
1095 both are defined, __getattribute__ is called first, and if it raises
1096 AttributeError, __getattr__ is called.
1097
1098- The __class__ attribute of new-style objects can be assigned to.
1099 The new class must have the same C-level object layout as the old
1100 class.
1101
1102- The builtin file type can be subclassed now. In the usual pattern,
1103 "file" is the name of the builtin type, and file() is a new builtin
1104 constructor, with the same signature as the builtin open() function.
1105 file() is now the preferred way to open a file.
1106
1107- Previously, __new__ would only see sequential arguments passed to
1108 the type in a constructor call; __init__ would see both sequential
1109 and keyword arguments. This made no sense whatsoever any more, so
1110 now both __new__ and __init__ see all arguments.
1111
1112- Previously, hash() applied to an instance of a subclass of str or
1113 unicode always returned 0. This has been repaired.
1114
1115- Previously, an operation on an instance of a subclass of an
1116 immutable type (int, long, float, complex, tuple, str, unicode),
1117 where the subtype didn't override the operation (and so the
1118 operation was handled by the builtin type), could return that
1119 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001120 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001121 with the same value as s.
1122
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001123- Provisional support for pickling new-style objects has been added.
1124
Guido van Rossum808eea72001-09-25 04:15:41 +00001125Core
1126
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001127- file.writelines() now accepts any iterable object producing strings.
1128
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001129- PyUnicode_FromEncodedObject() now works very much like
1130 PyObject_Str(obj) in that it tries to use __str__/tp_str
1131 on the object if the object is not a string or buffer. This
1132 makes unicode() behave like str() when applied to non-string/buffer
1133 objects.
1134
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001135- PyFile_WriteObject now passes Unicode objects to the file's write
1136 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001137 of a print statement must support Unicode objects, i.e. they must
1138 at least convert them into ASCII strings.
1139
Guido van Rossum624c8af2001-09-18 15:21:04 +00001140- Thread scheduling on Solaris should be improved; it is no longer
1141 necessary to insert a small sleep at the start of a thread in order
1142 to let other runnable threads be scheduled.
1143
Tim Petersb07352e2001-09-08 01:25:47 +00001144Library
1145
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001146- StringIO.StringIO instances and cStringIO.StringIO instances support
1147 read character buffer compatible objects for their .write() methods.
1148 These objects are converted to strings and then handled as such
1149 by the instances.
1150
Barry Warsaw2f600732001-09-24 04:28:10 +00001151- The "email" package has been added. This is basically a port of the
1152 mimelib package <http://sf.net/projects/mimelib> with API changes
1153 and some implementations updated to use iterators and generators.
1154
Tim Peters8a9c2842001-09-22 21:30:22 +00001155- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1156 restores the ability of Tools/scripts/ndiff.py to start producing output
1157 before the entire comparison is complete.
1158
Barry Warsaw58b072d2001-09-22 04:44:21 +00001159- StringIO.StringIO instances and cStringIO.StringIO instances support
1160 iteration just like file objects (i.e. their .readline() method is
1161 called for each iteration until it returns an empty string).
1162
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001163- The codecs module has grown four new helper APIs to access
1164 builtin codecs: getencoder(), getdecoder(), getreader(),
1165 getwriter().
1166
Guido van Rossum624c8af2001-09-18 15:21:04 +00001167- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1168 simplifies writing XML RPC servers.
1169
Barry Warsaw647d5e82001-09-28 17:01:02 +00001170- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001171 after interpretation of symbolic links. On non-Unix systems, this
1172 is an alias for os.path.abspath().
1173
Tim Peters16a77ad2001-09-08 04:00:12 +00001174- operator.indexOf() (PySequence_Index() in the C API) now works with any
1175 iterable object.
1176
Guido van Rossum624c8af2001-09-18 15:21:04 +00001177- smtplib now supports various authentication and security features of
1178 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001179
Guido van Rossum624c8af2001-09-18 15:21:04 +00001180- hmac: a new module implementing keyed hashing for message
1181 authentication.
1182
1183- mimetypes now recognizes more extensions and file types. At the
1184 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001185
Guido van Rossum624c8af2001-09-18 15:21:04 +00001186- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001187 Python 2.2 bytecode generation. It has also been promoted from a
1188 Tool to a standard library package. (Tools/compiler still exists as
1189 a sample driver.)
1190
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001191Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001192
Tim Petersb07352e2001-09-08 01:25:47 +00001193Build
1194
Guido van Rossum624c8af2001-09-18 15:21:04 +00001195- Large file support (LFS) is now automatic when the platform supports
1196 it; no more manual configuration tweaks are needed. On Linux, at
1197 least, it's possible to have a system whose C library supports large
1198 files but whose kernel doesn't; in this case, large file support is
1199 still enabled but doesn't do you any good unless you upgrade your
1200 kernel or share your Python executable with another system whose
1201 kernel has large file support.
1202
1203- The configure script now supplies plausible defaults in a
1204 cross-compilation environment. This doesn't mean that the supplied
1205 values are always correct, or that cross-compilation now works
1206 flawlessly -- but it's a first step (and it shuts up most of
1207 autoconf's warnings about AC_TRY_RUN).
1208
1209- The Unix build is now a bit less chatty, courtesy of the parser
1210 generator. The build is completely silent (except for errors) when
1211 using "make -s", thanks to a -q option to setup.py.
1212
Tim Petersb07352e2001-09-08 01:25:47 +00001213C API
1214
Guido van Rossum624c8af2001-09-18 15:21:04 +00001215- The "structmember" API now supports some new flag bits to deny read
1216 and/or write access to attributes in restricted execution mode.
1217
Tim Petersb07352e2001-09-08 01:25:47 +00001218New platforms
1219
Guido van Rossum624c8af2001-09-18 15:21:04 +00001220- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1221 (http://familiar.handhelds.org).
1222
Tim Petersb07352e2001-09-08 01:25:47 +00001223Tests
1224
Tim Peters8a9c2842001-09-22 21:30:22 +00001225- The "classic" standard tests, which work by comparing stdout to
1226 an expected-output file under Lib/test/output/, no longer stop at
1227 the first mismatch. Instead the test is run to completion, and a
1228 variant of ndiff-style comparison is used to report all differences.
1229 This is much easier to understand than the previous style of reporting.
1230
1231- The unittest-based standard tests now use regrtest's test_main()
1232 convention, instead of running as a side-effect of merely being
1233 imported. This allows these tests to be run in more natural and
1234 flexible ways as unittests, outside the regrtest framework.
1235
1236- regrtest.py is much better integrated with unittest and doctest now,
1237 especially in regard to reporting errors.
1238
Tim Petersb07352e2001-09-08 01:25:47 +00001239Windows
1240
Guido van Rossum624c8af2001-09-18 15:21:04 +00001241- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001242 that support it (NTFS under Windows 2000). See "What's New in
1243 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001244
Tim Petersb07352e2001-09-08 01:25:47 +00001245
Tim Petersedc99312001-08-22 21:36:50 +00001246What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001247Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001248===========================
1249
1250Core
1251
Tim Peters9fffa3e2001-09-04 05:14:19 +00001252- Conversion of long to float now raises OverflowError if the long is too
1253 big to represent as a C double.
1254
Tim Peters32f453e2001-09-03 08:35:41 +00001255- The 3-argument builtin pow() no longer allows a third non-None argument
1256 if either of the first two arguments is a float, or if both are of
1257 integer types and the second argument is negative (in which latter case
1258 the arguments are converted to float, so this is really the same
1259 restriction).
1260
Tim Peters5d2b77c2001-09-03 05:47:38 +00001261- The builtin dir() now returns more information, and sometimes much
1262 more, generally naming all attributes of an object, and all attributes
1263 reachable from the object via its class, and from its class's base
1264 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1265 an empty list. In 2.2a3,
1266
1267 >>> dir([])
1268 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1269 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1270 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1271 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1272 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1273 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1274 'reverse', 'sort']
1275
1276 dir(module) continues to return only the module's attributes, though.
1277
Tim Petersbdee63f2001-09-02 03:40:59 +00001278- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001279 than raising OverflowError. This is a partial implementation of PEP
1280 237. You can use -Wdefault::OverflowWarning to enable a warning for
1281 this situation, and -Werror::OverflowWarning to revert to the old
1282 OverflowError exception.
1283
Guido van Rossum61c345f2001-09-04 03:26:15 +00001284- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001285 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001286 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1287 -Qold, meaning the / operator has its classic meaning and no
1288 warnings are issued. Using -Qwarn issues a run-time warning about
1289 all uses of classic division for int and long arguments; -Qwarnall
1290 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001291 (for use with fixdiv.py).
1292 [Note: the remainder of this paragraph (preserved below) became
1293 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1294 <obsolete>
1295 Using -Qnew is questionable; it turns on new division by default, but
1296 only in the __main__ module. You can usefully combine -Qwarn or
1297 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1298 warns about classic division everywhere else.
1299 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001300
Tim Petersbdee63f2001-09-02 03:40:59 +00001301- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001302 long, float, str, unicode, and tuple. (The types complex, list and
1303 dictionary can also be subclassed; this was introduced earlier.)
1304 Note that restrictions apply when subclassing immutable built-in
1305 types: you can only affect the value of the instance by overloading
1306 __new__. You can add mutable attributes, and the subclass instances
1307 will have a __dict__ attribute, but you cannot change the "value"
1308 (as implemented by the base class) of an immutable subclass instance
1309 once it is created.
1310
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001311- The dictionary constructor now takes an optional argument, a
1312 mapping-like object, and initializes the dictionary from its
1313 (key, value) pairs.
1314
Tim Petersbdee63f2001-09-02 03:40:59 +00001315- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001316 "cooperative super calls" in a multiple inheritance setting. For an
1317 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1318
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001319- A new built-in type, property, has been added. This enables the
1320 creation of "properties". These are attributes implemented by
1321 getter and setter functions (or only one of these for read-only or
1322 write-only attributes), without the need to override __getattr__.
1323 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001324
Tim Petersbdee63f2001-09-02 03:40:59 +00001325- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001326 liberalized, to allow leading zeroes. Examples of literals now
1327 legal that were SyntaxErrors before:
1328
1329 00.0 0e3 0100j 07.5 00000000000000000008.
1330
Tim Petersbdee63f2001-09-02 03:40:59 +00001331- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001332 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1333
Tim Petersedc99312001-08-22 21:36:50 +00001334Library
1335
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001336- telnetlib includes symbolic names for the options, and support for
1337 setting an option negotiation callback.
1338
Tim Petersa40c7932001-09-05 22:36:56 +00001339- The new C standard no longer requires that math libraries set errno to
1340 ERANGE on overflow. For platform libraries that exploit this new
1341 freedom, Python's overflow-checking was wholly broken. A new overflow-
1342 checking scheme attempts to repair that, but may not be reliable on all
1343 platforms (C doesn't seem to provide anything both useful and portable
1344 in this area anymore).
1345
Martin v. Löwis44f86962001-09-05 13:44:54 +00001346- Asynchronous timeout actions are available through the new class
1347 threading.Timer.
1348
Tim Peters78526162001-09-05 00:53:45 +00001349- math.log and math.log10 now return sensible results for even huge
1350 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1351
Tim Petersbdee63f2001-09-02 03:40:59 +00001352- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001353 currently held. See the docs for the imp module.
1354
Tim Petersbdee63f2001-09-02 03:40:59 +00001355- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001356 dumps containing ints written on platforms where Python ints are 8 bytes.
1357 When read on a box where Python ints are 4 bytes, such values are
1358 converted to Python longs.
1359
Tim Petersbdee63f2001-09-02 03:40:59 +00001360- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001361 code objects is no longer allowed. This plugs a security hole.
1362
Steve Purcell6091cd62001-09-06 16:05:17 +00001363- unittest.TestResult instances no longer store references to tracebacks
1364 generated by test failures. This prevents unexpected dangling references
1365 to objects that should be garbage collected between tests.
1366
Tim Petersedc99312001-08-22 21:36:50 +00001367Tools
1368
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001369- Tools/scripts/fixdiv.py has been added which can be used to fix
1370 division operators as per PEP 238.
1371
Tim Petersedc99312001-08-22 21:36:50 +00001372Build
1373
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001374- If you are an adventurous person using Mac OS X you may want to look at
1375 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1376 application, which can be used for experimenting with Carbon or Cocoa.
1377 Discussion of this on pythonmac-sig, please.
1378
Tim Peters7eea37e2001-09-04 22:08:56 +00001379C API
1380
1381- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001382
Tim Peters9fffa3e2001-09-04 05:14:19 +00001383- Note that PyLong_AsDouble can fail! This has always been true, but no
1384 callers checked for it. It's more likely to fail now, because overflow
1385 errors are properly detected now. The proper way to check:
1386
1387 double x = PyLong_AsDouble(some_long_object);
1388 if (x == -1.0 && PyErr_Occurred()) {
1389 /* The conversion failed. */
1390 }
1391
Tim Petersbdee63f2001-09-02 03:40:59 +00001392- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001393 compile but will not participate in GC. To upgrade an extension
1394 module:
1395
1396 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001397
Neil Schemenauer4042c692001-08-30 15:38:01 +00001398 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1399 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001400
Neil Schemenauer4042c692001-08-30 15:38:01 +00001401 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1402 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001403
Neil Schemenauer4042c692001-08-30 15:38:01 +00001404 - remove PyGC_HEAD_SIZE from object size calculations
1405
1406 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1407
Tim Petersbdee63f2001-09-02 03:40:59 +00001408- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001409 These can be used safely to construct string objects from a
1410 sprintf-style format string (similar to the format string supported
1411 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001412
Tim Petersedc99312001-08-22 21:36:50 +00001413New platforms
1414
Tim Petersb7da0902001-09-02 23:01:43 +00001415- Stephen Hansen contributed patches sufficient to get a clean compile
1416 under Borland C (Windows), but he reports problems running it and ran
1417 out of time to complete the port. Volunteers? Expect a MemoryError
1418 when importing the types module; this is probably shallow, and
1419 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001420
Tim Petersedc99312001-08-22 21:36:50 +00001421Tests
1422
1423Windows
1424
Tim Peters6e13a562001-09-06 00:32:15 +00001425- Large file support is now enabled on Win32 platforms as well as on
1426 Win64. This means that, for example, you can use f.tell() and f.seek()
1427 to manipulate files larger than 2 gigabytes (provided you have enough
1428 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001429 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1430 filesize limit, and large file support makes no difference there.
1431 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1432 NTFS has no practical limit on file size, and files of any size can be
1433 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001434
Tim Petersbdee63f2001-09-02 03:40:59 +00001435- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001436 points to command.com (patch from Brian Quinlan).
1437
Tim Petersedc99312001-08-22 21:36:50 +00001438
Tim Peters20f51a72001-07-21 02:31:40 +00001439What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001440Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001441===========================
1442
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001443Build
1444
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001445- Tim Peters developed a brand new Windows installer using Wise 8.1,
1446 generously donated to us by Wise Solutions.
1447
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001448- configure supports a new option --enable-unicode, with the values
1449 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1450 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001451
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001452- A new configure option --enable-framework builds a Mac OS X framework,
1453 which "make frameworkinstall" will install. This provides a starting
1454 point for more mac-like functionality, join pythonmac-sig@python.org
1455 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001456
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001457- The NeXT platform is no longer supported.
1458
1459- The `new' module is now statically linked.
1460
Tim Peters0afb6092001-08-15 06:06:44 +00001461Tools
1462
1463- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001464 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001465 the module docstring for details.
1466
Tim Peters20f51a72001-07-21 02:31:40 +00001467Tests
1468
Tim Peters5e824c32001-08-12 22:25:01 +00001469- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001470 platforms, allowing to give clearer test result output. regrtest
1471 also has optional --use/-u switch to run normally disabled tests
1472 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001473
Tim Peters20f51a72001-07-21 02:31:40 +00001474- Several new tests in the standard test suite, with special thanks to
1475 Nick Mathewson.
1476
1477Core
1478
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001479- The floor division operator // has been added as outlined in PEP
1480 238. The / operator still provides classic division (and will until
1481 Python 3.0) unless "from __future__ import division" is included, in
1482 which case the / operator will provide true division. The operator
1483 module provides truediv() and floordiv() functions. Augmented
1484 assignment variants are included, as are the equivalent overloadable
1485 methods and C API methods. See the PEP for a full discussion:
1486 <http://python.sf.net/peps/pep-0238.html>
1487
Tim Peters6cd6a822001-08-17 22:11:27 +00001488- Future statements are now effective in simulated interactive shells
1489 (like IDLE). This should "just work" by magic, but read Michael
1490 Hudson's "Future statements in simulated shells" PEP 264 for full
1491 details: <http://python.sf.net/peps/pep-0264.html>.
1492
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001493- The type/class unification (PEP 252-253) was integrated into the
1494 trunk and is not so tentative any more (the exact specification of
1495 some features is still tentative). A lot of work has done on fixing
1496 bugs and adding robustness and features (performance still has to
1497 come a long way).
1498
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001499- Warnings about a mismatch in the Python API during extension import
1500 now use the Python warning framework (which makes it possible to
1501 write filters for these warnings).
1502
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001503- A function's __dict__ (aka func_dict) will now always be a
1504 dictionary. It used to be possible to delete it or set it to None,
1505 but now both actions raise TypeErrors. It is still legal to set it
1506 to a dictionary object. Getting func.__dict__ before any attributes
1507 have been assigned now returns an empty dictionary instead of None.
1508
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001509- A new command line option, -E, was added which disables the use of
1510 all environment variables, or at least those that are specifically
1511 significant to Python. Usually those have a name starting with
1512 "PYTHON". This was used to fix a problem where the tests fail if
1513 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1514 older distribution.
1515
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001516Library
1517
Tim Peters5e824c32001-08-12 22:25:01 +00001518- New class Differ and new functions ndiff() and restore() in difflib.py.
1519 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001520 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001521
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001522- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1523 value using the minimal quoting required for the value; more
1524 reliable than using xml.sax.saxutils.escape() for attribute values.
1525
1526- Readline completion support for cmd.Cmd was added.
1527
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001528- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1529
1530- Added function threading.BoundedSemaphore()
1531
1532- Added Ka-Ping Yee's cgitb.py module.
1533
1534- The `new' module now exposes the CO_xxx flags.
1535
Martin v. Löwis560da622001-11-24 09:24:51 +00001536- The gc module offers the get_referents function.
1537
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001538New platforms
1539
1540C API
1541
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001542- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1543 which provide a cross-platform implementations for the
1544 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1545 the standard sprintf() and vsprintf() C lib APIs, these versions
1546 apply bounds checking on the used buffer which enhances protection
1547 against buffer overruns.
1548
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001549- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001550 and extensions using different Unicode widths is rendered next to
1551 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001552 will result in an ImportError. Unicode extensions writers must make
1553 sure to check the Unicode width compatibility in their extensions by
1554 using at least one of the mangled Unicode APIs in the extension.
1555
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001556- Two new flags METH_NOARGS and METH_O are available in method definition
1557 tables to simplify implementation of methods with no arguments and a
1558 single untyped argument. Calling such methods is more efficient than
1559 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1560 deprecated.
1561
Tim Petersc1731372001-08-04 08:12:36 +00001562Windows
1563
1564- "import module" now compiles module.pyw if it exists and nothing else
1565 relevant is found.
1566
Tim Peters20f51a72001-07-21 02:31:40 +00001567
Guido van Rossum55a78992001-07-17 17:22:32 +00001568What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001569Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001570===========================
1571
1572Core
Tim Petersa814db52001-05-14 07:05:58 +00001573
Tim Peters6d6c1a32001-08-02 04:15:00 +00001574- TENTATIVELY, a large amount of code implementing much of what's
1575 described in PEP 252 (Making Types Look More Like Classes) and PEP
1576 253 (Subtyping Built-in Types) was added. This will be released
1577 with Python 2.2a1. Documentation will be provided separately
1578 through http://www.python.org/2.2/. The purpose of releasing this
1579 with Python 2.2a1 is to test backwards compatibility. It is
1580 possible, though not likely, that a decision is made not to release
1581 this code as part of 2.2 final, if any serious backwards
1582 incompapatibilities are found during alpha testing that cannot be
1583 repaired.
1584
Guido van Rossum55a78992001-07-17 17:22:32 +00001585- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001586 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001587 more 'yield' statements. See PEP 255. Since this adds a new
1588 keyword to the language, this feature must be enabled by including a
1589 future statement: "from __future__ import generators" (see PEP 236).
1590 Generators will become a standard feature in a future release
1591 (probably 2.3). Without this future statement, 'yield' remains an
1592 ordinary identifier, but a warning is issued each time it is used.
1593 (These warnings currently don't conform to the warnings framework of
1594 PEP 230; we intend to fix this in 2.2a2.)
1595
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001596- The UTF-16 codec was modified to be more RFC compliant. It will now
1597 only remove BOM characters at the start of the string and then
1598 only if running in native mode (UTF-16-LE and -BE won't remove a
1599 leading BMO character).
1600
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001601- Strings now have a new method .decode() to complement the already
1602 existing .encode() method. These two methods provide direct access
1603 to the corresponding decoders and encoders of the registered codecs.
1604
1605 To enhance the usability of the .encode() method, the special
1606 casing of Unicode object return values was dropped (Unicode objects
1607 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001608
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001609 Both methods will now return whatever the codec in charge of the
1610 requested encoding returns as object, e.g. Unicode codecs will
1611 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1612 will return u"äöü"). This enables codec writer to create codecs
1613 for various simple to use conversions.
1614
1615 New codecs were added to demonstrate these new features (the .encode()
1616 and .decode() columns indicate the type of the returned objects):
1617
1618 Name | .encode() | .decode() | Description
1619 ----------------------------------------------------------------------
1620 uu | string | string | UU codec (e.g. for email)
1621 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001622 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001623 zlib | string | string | zlib compression
1624 hex | string | string | 2-byte hex codec
1625 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1626
Mark Hammond2a0af792001-05-14 03:09:36 +00001627- Some operating systems now support the concept of a default Unicode
1628 encoding for file system operations. Notably, Windows supports 'mbcs'
1629 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001630 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001631 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001632
1633 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001634 functions that return filenames (such as os.listdir()) to return Python
1635 string objects pre-encoded using the default file system encoding for
1636 the platform. As this encoding is likely to be different from Python's
1637 default encoding, converting this name to a Unicode object before passing
1638 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001639 would attempt to use its default encoding (generally ASCII) rather than
1640 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001641
Tim Petersa814db52001-05-14 07:05:58 +00001642 In general, this change simply removes surprises when working with
1643 Unicode and the file system, making these operations work as you expect,
1644 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001645 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001646
Tim Peters61dff2b2001-05-08 15:43:37 +00001647- Float (and complex) literals in source code were evaluated to full
1648 precision only when running from a .py file; the same code loaded from a
1649 .pyc (or .pyo) file could suffer numeric differences starting at about the
1650 12th significant decimal digit. For example, on a machine with IEEE-754
1651 floating arithmetic,
1652
1653 x = 9007199254740992.0
1654 print long(x)
1655
1656 printed 9007199254740992 if run directly from .py, but 9007199254740000
1657 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1658 str(float) instead of repr(float) when building code objects. marshal
1659 now uses repr(float) instead, which should reproduce floats to full
1660 machine precision (assuming the platform C float<->string I/O conversion
1661 functions are of good quality).
1662
1663 This may cause floating-point results to change in some cases, and
1664 usually for the better, but may also cause numerically unstable
1665 algorithms to break.
1666
Tim Peters2f228e72001-05-13 00:19:31 +00001667- The implementation of dicts suffers fewer collisions, which has speed
1668 benefits. However, the order in which dict entries appear in dict.keys(),
1669 dict.values() and dict.items() may differ from previous releases for a
1670 given dict. Nothing is defined about this order, so no program should
1671 rely on it. Nevertheless, it's easy to write test cases that rely on the
1672 order by accident, typically because of printing the str() or repr() of a
1673 dict to an "expected results" file. See Lib/test/test_support.py's new
1674 sortdict(dict) function for a simple way to display a dict in sorted
1675 order.
1676
Tim Peters7a3bfc32001-06-12 01:22:22 +00001677- Many other small changes to dicts were made, resulting in faster
1678 operation along the most common code paths.
1679
Guido van Rossum10315822001-05-01 20:54:30 +00001680- Dictionary objects now support the "in" operator: "x in dict" means
1681 the same as dict.has_key(x).
1682
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001683- The update() method of dictionaries now accepts generic mapping
1684 objects. Specifically the argument object must support the .keys()
1685 and __getitem__() methods. This allows you to say, for example,
1686 {}.update(UserDict())
1687
Guido van Rossum10315822001-05-01 20:54:30 +00001688- Iterators were added; this is a generalized way of providing values
1689 to a for loop. See PEP 234. There's a new built-in function iter()
1690 to return an iterator. There's a new protocol to get the next value
1691 from an iterator using the next() method (in Python) or the
1692 tp_iternext slot (in C). There's a new protocol to get iterators
1693 using the __iter__() method (in Python) or the tp_iter slot (in C).
1694 Iterating (i.e. a for loop) over a dictionary generates its keys.
1695 Iterating over a file generates its lines.
1696
Tim Petersf553f892001-05-01 20:45:31 +00001697- The following functions were generalized to work nicely with iterator
1698 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001699 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001700 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1701 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001702 join() method of strings
1703 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001704 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1705 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001706 right-hand side of assignment statements with multiple targets, such as
1707 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001708
Tim Petersd85e1022001-05-11 21:51:48 +00001709- Accessing module attributes is significantly faster (for example,
1710 random.random or os.path or yourPythonModule.yourAttribute).
1711
Tim Peterse63415e2001-05-08 04:38:29 +00001712- Comparing dictionary objects via == and != is faster, and now works even
1713 if the keys and values don't support comparisons other than ==.
1714
Tim Peters95bf9392001-05-10 08:32:44 +00001715- Comparing dictionaries in ways other than == and != is slower: there were
1716 insecurities in the dict comparison implementation that could cause Python
1717 to crash if the element comparison routines for the dict keys and/or
1718 values mutated the dicts. Making the code bulletproof slowed it down.
1719
Tim Peterseb28ef22001-06-02 05:27:19 +00001720- Collisions in dicts are resolved via a new approach, which can help
1721 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001722 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001723 faster now. Thanks to Christian Tismer for pointing out the cause and
1724 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001725
Tim Peters52e155e2001-06-16 05:42:57 +00001726- repr() is much faster for large containers (dict, list, tuple).
1727
1728
Tim Petersa814db52001-05-14 07:05:58 +00001729Library
1730
Fred Drake960fdf92001-07-20 18:38:26 +00001731- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1732 were added to the string module. These a locale-indenpendent
1733 constants, unlike letters, lowercase, and uppercase. These are now
1734 use in appropriate locations in the standard library.
1735
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001736- The flags used in dlopen calls can now be configured using
1737 sys.setdlopenflags and queried using sys.getdlopenflags.
1738
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001739- Fredrik Lundh's xmlrpclib is now a standard library module. This
1740 provides full client-side XML-RPC support. In addition,
1741 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1742 one asyncore-based). Thanks to Eric Raymond for the documentation.
1743
Guido van Rossum643d3912001-07-05 14:46:25 +00001744- The xrange() object is simplified: it no longer supports slicing,
1745 repetition, comparisons, efficient 'in' checking, the tolist()
1746 method, or the start, stop and step attributes. See PEP 260.
1747
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001748- A new function fnmatch.filter to filter lists of file names was added.
1749
Barry Warsawffd674d2001-05-22 16:00:10 +00001750- calendar.py uses month and day names based on the current locale.
1751
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001752- strop is now *really* obsolete (this was announced before with 1.6),
1753 and issues DeprecationWarning when used (except for the four items
1754 that are still imported into string.py).
1755
Tim Petersa814db52001-05-14 07:05:58 +00001756- Cookie.py now sorts key+value pairs by key in output strings.
1757
1758- pprint.isrecursive(object) didn't correctly identify recursive objects.
1759 Now it does.
1760
Tim Peters95b3f782001-05-14 18:39:41 +00001761- pprint functions now much faster for large containers (tuple, list, dict).
1762
Tim Peters7b9542a2001-06-10 23:40:19 +00001763- New 'q' and 'Q' format codes in the struct module, corresponding to C
1764 types "long long" and "unsigned long long" (on Windows, __int64). In
1765 native mode, these can be used only when the platform C compiler supports
1766 these types (when HAVE_LONG_LONG is #define'd by the Python config
1767 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001768 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1769 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001770
Guido van Rossum83213cc2001-06-12 16:48:52 +00001771- The site module installs a new built-in function 'help' that invokes
1772 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1773 it displays a message reminding the user to use 'help()' or
1774 'help(object)'.
1775
Tim Petersa814db52001-05-14 07:05:58 +00001776Tests
1777
1778- New test_mutants.py runs dict comparisons where the key and value
1779 comparison operators mutute the dicts randomly during comparison. This
1780 rapidly causes Python to crash under earlier releases (not for the faint
1781 of heart: it can also cause Win9x to freeze or reboot!).
1782
1783- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001784 pprint.isreadable() return sensible results. Also verifies that simple
1785 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001786
Tim Peters4324aa32001-05-28 22:30:08 +00001787C API
1788
1789- Removed the unused last_is_sticky argument from the internal
1790 _PyTuple_Resize(). If this affects you, you were cheating.
1791
1792
Guido van Rossum55a78992001-07-17 17:22:32 +00001793======================================================================
1794
1795
Guido van Rossumffe13be2001-04-16 18:46:45 +00001796What's New in Python 2.1 (final)?
1797=================================
1798
1799We only changed a few things since the last release candidate, all in
1800Python library code:
1801
1802- A bug in the locale module was fixed that affected locales which
1803 define no grouping for numeric formatting.
1804
1805- A few bugs in the weakref module's implementations of weak
1806 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1807 and the test suite was updated to check for these bugs.
1808
1809- An old bug in the os.path.walk() function (introduced in Python
1810 2.0!) was fixed: a non-existent file would cause an exception
1811 instead of being ignored.
1812
1813- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1814 PyChecker.
1815
1816
Guido van Rossum5b08f132001-04-16 02:05:23 +00001817What's New in Python 2.1c2?
1818===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001819
Guido van Rossum5b08f132001-04-16 02:05:23 +00001820A flurry of small changes, and one showstopper fixed in the nick of
1821time made it necessary to release another release candidate. The list
1822here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001823
Guido van Rossum5b08f132001-04-16 02:05:23 +00001824Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001825
Guido van Rossum5b08f132001-04-16 02:05:23 +00001826- Tim discovered a nasty bug in the dictionary code, caused by
1827 PyDict_Next() calling dict_resize(), and the GC code's use of
1828 PyDict_Next() violating an assumption in dict_items(). This was
1829 fixed with considerable amounts of band-aid, but the net effect is a
1830 saner and more robust implementation.
1831
1832- Made a bunch of symbols static that were accidentally global.
1833
1834Build and Ports
1835
1836- The setup.py script didn't check for a new enough version of zlib
1837 (1.1.3 is needed). Now it does.
1838
1839- Changed "make clean" target to also remove shared libraries.
1840
1841- Added a more general warning about the SGI Irix optimizer to README.
1842
1843Library
1844
1845- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1846 omitted the slash between host and file.html.
1847
1848- The mailbox module's _Mailbox class contained a completely broken
1849 and undocumented seek() method. Ripped it out.
1850
1851- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1852 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1853
1854- Fixed a few last-minute bugs in unittest.
1855
1856Extensions
1857
1858- Reverted the patch to the OpenSSL code in socketmodule.c to support
1859 RAND_status() and the EGD, and the subsequent patch that tried to
1860 fix it for pre-0.9.5 versions; the problem with the patch is that on
1861 some systems it issues a warning whenever socket is imported, and
1862 that's unacceptable.
1863
1864Tests
1865
1866- Fixed the pickle tests to work with "import test.test_pickle".
1867
1868- Tweaked test_locale.py to actually run the test Windows.
1869
1870- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1871 not "wb" (which is not a valid mode at all).
1872
1873- Fix pstats browser crashes. Import readline if it exists to make
1874 the user interface nicer.
1875
1876- Add "import thread" to the top of test modules that import the
1877 threading module (test_asynchat and test_threadedtempfile). This
1878 prevents test failures caused by a broken threading module resulting
1879 from a previously caught failed import.
1880
1881- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1882 needed on some platforms (e.g. Solaris 8) when the tests are run
1883 twice in succession.
1884
1885- Skip rather than fail test_sunaudiodev if no audio device is found.
1886
1887
1888What's New in Python 2.1c1?
1889===========================
1890
1891This list was significantly updated when 2.1c2 was released; the 2.1c1
1892release didn't mention most changes that were actually part of 2.1c1:
1893
1894Legal
1895
1896- Copyright was assigned to the Python Software Foundation (PSF) and a
1897 PSF license (very similar to the CNRI license) was added.
1898
1899- The CNRI copyright notice was updated to include 2001.
1900
1901Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001902
Guido van Rossumc9932722001-04-12 02:31:27 +00001903- After a public outcry, assignment to __debug__ is no longer illegal;
1904 instead, a warning is issued. It will become illegal in 2.2.
1905
Guido van Rossum5b08f132001-04-16 02:05:23 +00001906- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1907 "%#x" now always prepends "0x", even if the value is zero.
1908
1909- Fixed some nits in the bytecode compiler.
1910
1911- Fixed core dumps when calling certain kinds of non-functions.
1912
1913- Fixed various core dumps caused by reference count bugs.
1914
1915Build and Ports
1916
1917- Use INSTALL_SCRIPT to install script files.
1918
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001919- New port: SCO Unixware 7, by Billy G. Allie.
1920
Guido van Rossum5b08f132001-04-16 02:05:23 +00001921- Updated RISCOS port.
1922
1923- Updated BeOS port and notes.
1924
1925- Various other porting problems resolved.
1926
1927Library
1928
1929- The TERMIOS and SOCKET modules are now truly obsolete and
1930 unnecessary. Their symbols are incorporated in the termios and
1931 socket modules.
1932
1933- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1934 better tests for pickling.
1935
1936- threading: make Condition.wait() robust against KeyboardInterrupt.
1937
1938- zipfile: add support to zipfile to support opening an archive
1939 represented by an open file rather than a file name. Fix bug where
1940 the archive was not properly closed. Fixed a bug in this bugfix
1941 where flush() was called for a read-only file.
1942
1943- imputil: added an uninstall() method to the ImportManager.
1944
1945- Canvas: fixed bugs in lower() and tkraise() methods.
1946
1947- SocketServer: API change (added overridable close_request() method)
1948 so that the TCP server can explicitly close the request.
1949
1950- pstats: Eric Raymond added a simple interactive statistics browser,
1951 invoked when the module is run as a script.
1952
1953- locale: fixed a problem in format().
1954
1955- webbrowser: made it work when the BROWSER environment variable has a
1956 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1957 KDE 2. Fixed some other nits.
1958
1959- unittest: changes to allow using a different exception than
1960 AssertionError, and added a few more function aliases. Some other
1961 small changes.
1962
1963- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1964
1965- asynchat: fixed a critical bug in asynchat that slipped through the
1966 2.1b2 release. Fixed another rare bug.
1967
1968- Fix some unqualified except: clauses (always a bad code example).
1969
1970XML
1971
1972- pyexpat: new API get_version_string().
1973
1974- Fixed some minidom bugs.
1975
1976Extensions
1977
1978- Fixed a core dump in _weakref. Removed the weakref.mapping()
1979 function (it adds nothing to the API).
1980
1981- Rationalized the use of header files in the readline module, to make
1982 it compile (albeit with some warnings) with the very recent readline
1983 4.2, without breaking for earlier versions.
1984
1985- Hopefully fixed a buffering problem in linuxaudiodev.
1986
1987- Attempted a fix to make the OpenSSL support in the socket module
1988 work again with pre-0.9.5 versions of OpenSSL.
1989
1990Tests
1991
1992- Added a test case for asynchat and asyncore.
1993
1994- Removed coupling between tests where one test failing could break
1995 another.
1996
1997Tools
1998
1999- Ping added an interactive help browser to pydoc, fixed some nits
2000 in the rest of the pydoc code, and added some features to his
2001 inspect module.
2002
2003- An updated python-mode.el version 4.1 which integrates Ken
2004 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2005 much nicer in XEmacs and Emacs. When stepping through your program
2006 with pdb, in either the shell window or the *Python* window, the
2007 source file and line will be tracked by an arrow. Very cool!
2008
2009- IDLE: syntax warnings in interactive mode are changed into errors.
2010
2011- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002012 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002013
2014- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002015
Barry Warsaw11e89c72001-04-11 20:37:57 +00002016
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002017What's New in Python 2.1 beta 2?
2018================================
2019
Guido van Rossum053ae352001-03-22 14:17:21 +00002020(Unlisted are many fixed bugs, more documentation, etc.)
2021
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002022Core language, builtins, and interpreter
2023
Guido van Rossum053ae352001-03-22 14:17:21 +00002024- The nested scopes work (enabled by "from __future__ import
2025 nested_scopes") is completed; in particular, the future now extends
2026 into code executed through exec, eval() and execfile(), and into the
2027 interactive interpreter.
2028
2029- When calling a base class method (e.g. BaseClass.__init__(self)),
2030 this is now allowed even if self is not strictly spoken a class
2031 instance (e.g. when using metaclasses or the Don Beaudry hook).
2032
2033- Slice objects are now comparable but not hashable; this prevents
2034 dict[:] from being accepted but meaningless.
2035
2036- Complex division is now calculated using less braindead algorithms.
2037 This doesn't change semantics except it's more likely to give useful
2038 results in extreme cases. Complex repr() now uses full precision
2039 like float repr().
2040
2041- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2042
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002043- It is illegal to assign to the name __debug__, which is set when the
2044 interpreter starts. It is effectively a compile-time constant.
2045
2046- A warning will be issued if a global statement for a variable
2047 follows a use or assignment of that variable.
2048
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002049Standard library
2050
Guido van Rossum053ae352001-03-22 14:17:21 +00002051- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2052 inspired by JUnit), is now part of the standard library. You now
2053 have a choice of two testing frameworks: unittest requires you to
2054 write testcases as separate code, doctest gathers them from
2055 docstrings. Both approaches have their advantages and
2056 disadvantages.
2057
2058- A new module Tix was added, which wraps the Tix extension library
2059 for Tk. With that module, it is not necessary to statically link
2060 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2061 require" command. See Demo/tix/.
2062
2063- tzparse.py is now obsolete.
2064
2065- In gzip.py, the seek() and tell() methods are removed -- they were
2066 non-functional anyway, and it's better if callers can test for their
2067 existence with hasattr().
2068
2069Python/C API
2070
2071- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2072 that's already in the dictionary during a PyDict_Next() iteration.
2073 This used to fail occasionally when a dictionary resize operation
2074 could be triggered that would rehash all the keys. All other
2075 modifications to the dictionary are still off-limits during a
2076 PyDict_Next() iteration!
2077
2078- New extended APIs related to passing compiler variables around.
2079
2080- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2081 implement isinstance() and issubclass().
2082
2083- Py_BuildValue() now has a "D" conversion to create a Python complex
2084 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002085
Fred Drake4e262a92001-03-22 18:26:47 +00002086- Extensions types which support weak references must now set the
2087 field allocated for the weak reference machinery to NULL themselves;
2088 this is done to avoid the cost of checking each object for having a
2089 weakly referencable type in PyObject_INIT(), since most types are
2090 not weakly referencable.
2091
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002092- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2093 free variables and cell variables to and from the frame's f_locals.
2094
2095- Variants of several functions defined in pythonrun.h have been added
2096 to support the nested_scopes future statement. The variants all end
2097 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2098 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2099 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002100 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002101
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002102Distutils
2103
2104- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2105 into the release tree.
2106
Tim Peters0e57abf2001-05-02 07:39:38 +00002107- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002108 (an uninstaller, more customization of the installer's display)
2109
2110- from Jack Jansen: added Mac-specific code to generate a dialog for
2111 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002112 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002113 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002114
2115- added 'platforms' and 'keywords' to the set of metadata that can be
2116 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002117
2118- applied patches from Jason Tishler to make the compiler class work with
2119 Cygwin.
2120
2121
Tim Peters2fe289a2001-03-01 22:19:38 +00002122What's New in Python 2.1 beta 1?
2123================================
Tim Petersd66595f2001-02-04 03:09:53 +00002124
2125Core language, builtins, and interpreter
2126
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002127- Following an outcry from the community about the amount of code
2128 broken by the nested scopes feature introduced in 2.1a2, we decided
2129 to make this feature optional, and to wait until Python 2.2 (or at
2130 least 6 months) to make it standard. The option can be enabled on a
2131 per-module basis by adding "from __future__ import nested_scopes" at
2132 the beginning of a module (before any other statements, but after
2133 comments and an optional docstring). See PEP 236 (Back to the
2134 __future__) for a description of the __future__ statement. PEP 227
2135 (Statically Nested Scopes) has been updated to reflect this change,
2136 and to clarify the semantics in a number of endcases.
2137
2138- The nested scopes code, when enabled, has been hardened, and most
2139 bugs and memory leaks in it have been fixed.
2140
2141- Compile-time warnings are now generated for a number of conditions
2142 that will break or change in meaning when nested scopes are enabled:
2143
2144 - Using "from...import *" or "exec" without in-clause in a function
2145 scope that also defines a lambda or nested function with one or
2146 more free (non-local) variables. The presence of the import* or
2147 bare exec makes it impossible for the compiler to determine the
2148 exact set of local variables in the outer scope, which makes it
2149 impossible to determine the bindings for free variables in the
2150 inner scope. To avoid the warning about import *, change it into
2151 an import of explicitly name object, or move the import* statement
2152 to the global scope; to avoid the warning about bare exec, use
2153 exec...in... (a good idea anyway -- there's a possibility that
2154 bare exec will be deprecated in the future).
2155
2156 - Use of a global variable in a nested scope with the same name as a
2157 local variable in a surrounding scope. This will change in
2158 meaning with nested scopes: the name in the inner scope will
2159 reference the variable in the outer scope rather than the global
2160 of the same name. To avoid the warning, either rename the outer
2161 variable, or use a global statement in the inner function.
2162
Neil Schemenauera35c6882001-02-27 04:45:05 +00002163- An optional object allocator has been included. This allocator is
2164 optimized for Python objects and should be faster and use less memory
2165 than the standard system allocator. It is not enabled by default
2166 because of possible thread safety problems. The allocator is only
2167 protected by the Python interpreter lock and it is possible that some
2168 extension modules require a thread safe allocator. The object
2169 allocator can be enabled by providing the "--with-pymalloc" option to
2170 configure.
2171
Tim Petersd66595f2001-02-04 03:09:53 +00002172Standard library
2173
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002174- pyexpat now detects the expat version if expat.h defines it. A
2175 number of additional handlers are provided, which are only available
2176 since expat 1.95. In addition, the methods SetParamEntityParsing and
2177 GetInputContext of Parser objects are available with 1.95.x
2178 only. Parser objects now provide the ordered_attributes and
2179 specified_attributes attributes. A new module expat.model was added,
2180 which offers a number of additional constants if 1.95.x is used.
2181
2182- xml.dom offers the new functions registerDOMImplementation and
2183 getDOMImplementation.
2184
2185- xml.dom.minidom offers a toprettyxml method. A number of DOM
2186 conformance issues have been resolved. In particular, Element now
2187 has an hasAttributes method, and the handling of namespaces was
2188 improved.
2189
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002190- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2191 getting information about live Python code, and pydoc.py, a module
2192 for interactively converting docstrings to HTML or text.
2193 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002194 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002195 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2196 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002197
Tim Peters1eff7962001-03-01 02:31:33 +00002198- New library module difflib.py, primarily packaging the SequenceMatcher
2199 class at the heart of the popular ndiff.py file-comparison tool.
2200
2201- doctest.py (a framework for verifying Python code examples in docstrings)
2202 is now part of the std library.
2203
Tim Petersd66595f2001-02-04 03:09:53 +00002204Windows changes
2205
Guido van Rossume3955a82001-03-02 14:05:59 +00002206- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2207 small GUI that lets you browse the module docstrings using your
2208 default web browser.
2209
Tim Peters1eff7962001-03-01 02:31:33 +00002210- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2211 Platforms) is implemented. See
2212
2213 http://python.sourceforge.net/peps/pep-0235.html
2214
2215 for full details, especially the "Current Lower-Left Semantics" section.
2216 The new Windows import rules are simpler than before:
2217
2218 A. If the PYTHONCASEOK environment variable exists, same as
2219 before: silently accept the first case-insensitive match of any
2220 kind; raise ImportError if none found.
2221
2222 B. Else search sys.path for the first case-sensitive match; raise
2223 ImportError if none found.
2224
2225 The same rules have been implented on other platforms with case-
2226 insensitive but case-preserving filesystems too (including Cygwin, and
2227 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002228
Tim Peters25a9ce32001-02-19 07:06:36 +00002229- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2230 what it's supposed to do (and does do under NT and 2000) via direct
2231 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002232 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002233 all Win9x systems before.
2234
Tim Peters1eff7962001-03-01 02:31:33 +00002235- Build: Subproject _test (effectively) renamed to _testcapi.
2236
Tim Peters2fe289a2001-03-01 22:19:38 +00002237New platforms
2238
2239- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2240 Thanks to Steven Majewski!
2241
2242- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2243 Tishler!
2244
Guido van Rossum9089b272001-03-02 06:49:50 +00002245- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2246 Schwertberger! See RISCOS/README for more information -- it seems
2247 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002248 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002249
Tim Peters25a9ce32001-02-19 07:06:36 +00002250
Tim Petersd7b5e882001-01-25 03:36:26 +00002251What's New in Python 2.1 alpha 2?
2252=================================
Tim Peters40ead762001-01-27 05:35:26 +00002253
Tim Petersd7b5e882001-01-25 03:36:26 +00002254Core language, builtins, and interpreter
2255
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002256- Scopes nest. If a name is used in a function or class, but is not
2257 local, the definition in the nearest enclosing function scope will
2258 be used. One consequence of this change is that lambda statements
2259 could reference variables in the namespaces where the lambda is
2260 defined. In some unusual cases, this change will break code.
2261
2262 In all previous version of Python, names were resolved in exactly
2263 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002264 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002265 function A is defined within a function B, the names bound in B are
2266 not visible in A. The new rules make names bound in B visible in A,
2267 unless A contains a name binding that hides the binding in B.
2268
2269 Section 4.1 of the reference manual describes the new scoping rules
2270 in detail. The test script in Lib/test/test_scope.py demonstrates
2271 some of the effects of the change.
2272
2273 The new rules will cause existing code to break if it defines nested
2274 functions where an outer function has local variables with the same
2275 name as globals or builtins used by the inner function. Example:
2276
2277 def munge(str):
2278 def helper(x):
2279 return str(x)
2280 if type(str) != type(''):
2281 str = helper(str)
2282 return str.strip()
2283
2284 Under the old rules, the name str in helper() is bound to the
2285 builtin function str(). Under the new rules, it will be bound to
2286 the argument named str and an error will occur when helper() is
2287 called.
2288
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002289- The compiler will report a SyntaxError if "from ... import *" occurs
2290 in a function or class scope. The language reference has documented
2291 that this case is illegal, but the compiler never checked for it.
2292 The recent introduction of nested scope makes the meaning of this
2293 form of name binding ambiguous. In a future release, the compiler
2294 may allow this form when there is no possibility of ambiguity.
2295
Tim Peters40ead762001-01-27 05:35:26 +00002296- repr(string) is easier to read, now using hex escapes instead of octal,
2297 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2298
2299 >>> "\texample \r\n" + chr(0) + chr(255)
2300 '\texample \r\n\x00\xff' # in 2.1
2301 '\011example \015\012\000\377' # in 2.0
2302
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002303- Functions are now compared and hashed by identity, not by value, since
2304 the func_code attribute is writable.
2305
Fred Drakefb9d7122001-02-01 20:00:40 +00002306- Weak references (PEP 205) have been added. This involves a few
2307 changes in the core, an extension module (_weakref), and a Python
2308 module (weakref). The weakref module is the public interface. It
2309 includes support for "explicit" weak references, proxy objects, and
2310 mappings with weakly held values.
2311
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002312- A 'continue' statement can now appear in a try block within the body
2313 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002314 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002315
Tim Petersd7b5e882001-01-25 03:36:26 +00002316Standard library
2317
Barry Warsaw30dbd142001-01-31 22:14:01 +00002318- mailbox.py now has a new class, PortableUnixMailbox which is
2319 identical to UnixMailbox but uses a more portable scheme for
2320 determining From_ separators. Also, the constructors for all the
2321 classes in this module have a new optional `factory' argument, which
2322 is a callable used when new message classes must be instantiated by
2323 the next() method.
2324
Tim Petersd7b5e882001-01-25 03:36:26 +00002325- random.py is now self-contained, and offers all the functionality of
2326 the now-deprecated whrandom.py. See the docs for details. random.py
2327 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002328 and restoring the internal state of the generator; and jumpahead(n),
2329 for quickly forcing the internal state to be the same as if n calls to
2330 random() had been made. The latter is particularly useful for multi-
2331 threaded programs, creating one instance of the random.Random() class for
2332 each thread, then using .jumpahead() to force each instance to use a
2333 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002334
Tim Peters0de88fc2001-02-01 04:59:18 +00002335- random.py's seed() function is new. For bit-for-bit compatibility with
2336 prior releases, use the whseed function instead. The new seed function
2337 addresses two problems: (1) The old function couldn't produce more than
2338 about 2**24 distinct internal states; the new one about 2**45 (the best
2339 that can be done in the Wichmann-Hill generator). (2) The old function
2340 sometimes produced identical internal states when passed distinct
2341 integers, and there was no simple way to predict when that would happen;
2342 the new one guarantees to produce distinct internal states for all
2343 arguments in [0, 27814431486576L).
2344
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002345- The socket module now supports raw packets on Linux. The socket
2346 family is AF_PACKET.
2347
Tim Peters9ea17ac2001-02-02 05:57:15 +00002348- test_capi.py is a start at running tests of the Python C API. The tests
2349 are implemented by the new Modules/_testmodule.c.
2350
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002351- A new extension module, _symtable, provides provisional access to the
2352 internal symbol table used by the Python compiler. A higher-level
2353 interface will be added on top of _symtable in a future release.
2354
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002355- Removed the obsolete soundex module.
2356
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002357- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2358 the isSameNode method; NamedNodeMap the get method.
2359
2360- xml.sax.expatreader supports the lexical handler property; it
2361 generates comment, startCDATA, and endCDATA events.
2362
Tim Petersee826f82001-01-31 19:39:44 +00002363Windows changes
2364
2365- Build procedure: the zlib project is built in a different way that
2366 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002367 the zlib binary used. See PCbuild\readme.txt for details. Your old
2368 zlib-related directories can be deleted; you'll need to download fresh
2369 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002370
Tim Peters9ea17ac2001-02-02 05:57:15 +00002371- Build: New subproject _test for the benefit of test_capi.py (see above).
2372
Tim Petersb16c56f2001-02-02 21:24:51 +00002373- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2374 interface to some Python compiler internals).
2375
2376- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002377 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002378
Tim Petersa3a3a032000-11-30 05:22:44 +00002379What's New in Python 2.1 alpha 1?
2380=================================
2381
2382Core language, builtins, and interpreter
2383
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002384- There is a new Unicode companion to the PyObject_Str() API
2385 called PyObject_Unicode(). It behaves in the same way as the
2386 former, but assures that the returned value is an Unicode object
2387 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002388
Guido van Rossumf98eda02001-01-17 15:54:45 +00002389- The comparison operators support "rich comparison overloading" (PEP
2390 207). C extension types can provide a rich comparison function in
2391 the new tp_richcompare slot in the type object. The cmp() function
2392 and the C function PyObject_Compare() first try the new rich
2393 comparison operators before trying the old 3-way comparison. There
2394 is also a new C API PyObject_RichCompare() (which also falls back on
2395 the old 3-way comparison, but does not constrain the outcome of the
2396 rich comparison to a Boolean result).
2397
2398 The rich comparison function takes two objects (at least one of
2399 which is guaranteed to have the type that provided the function) and
2400 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2401 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2402 object, which may be NotImplemented (in which case the tp_compare
2403 slot function is used as a fallback, if defined).
2404
2405 Classes can overload individual comparison operators by defining one
2406 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002407 __ge__. There are no explicit "reflected argument" versions of
2408 these; instead, __lt__ and __gt__ are each other's reflection,
2409 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2410 reflection (similar at the C level). No other implications are
2411 made; in particular, Python does not assume that == is the Boolean
2412 inverse of !=, or that < is the Boolean inverse of >=. This makes
2413 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002414
2415 Classes or types that want to implement (in)equality tests but not
2416 the ordering operators (i.e. unordered types) should implement ==
2417 and !=, and raise an error for the ordering operators.
2418
Guido van Rossuma88479f2001-01-18 14:28:08 +00002419 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002420 Boolean; e.g. a matrix type might want to return a matrix of bits
2421 for A < B, giving elementwise comparisons. Such types should ensure
2422 that any interpretation of their value in a Boolean context raises
2423 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2424 at the C level) to always raise an exception.
2425
Guido van Rossuma88479f2001-01-18 14:28:08 +00002426- Complex numbers use rich comparisons to define == and != but raise
2427 an exception for <, <=, > and >=. Unfortunately, this also means
2428 that cmp() of two complex numbers raises an exception when the two
2429 numbers differ. Since it is not mathematically meaningful to compare
2430 complex numbers except for equality, I hope that this doesn't break
2431 too much code.
2432
Tim Peters3389f192001-02-18 08:48:49 +00002433- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002434 not defined by the language, other than that it's arbitrary but
2435 consistent (see the Reference Manual). An implementation detail changed
2436 in 2.1a1 such that None now compares less than any other object. Code
2437 relying on this new behavior (like code that relied on the previous
2438 behavior) does so at its own risk.
2439
Barry Warsaw573b5412001-01-15 20:43:18 +00002440- Functions and methods now support getting and setting arbitrarily
2441 named attributes (PEP 232). Functions have a new __dict__
2442 (a.k.a. func_dict) which hold the function attributes. Methods get
2443 and set attributes on their underlying im_func. It is a TypeError
2444 to set an attribute on a bound method.
2445
Guido van Rossum051e3352001-01-15 19:11:10 +00002446- The xrange() object implementation has been improved so that
2447 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2448 limitation that in this case len(xrange(sys.maxint)) can't be
2449 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2450 work fine as long as the index i doesn't actually reach 2**31.
2451 (Python uses regular ints for sequence and string indices; fixing
2452 that is much more work.)
2453
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002454- Two changes to from...import:
2455
Guido van Rossumba381232001-02-03 15:06:40 +00002456 1) "from M import X" now works even if (after loading module M)
2457 sys.modules['M'] is not a real module; it's basically a getattr()
2458 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002459
2460 2) "from M import *" now looks for M.__all__ to decide which names to
2461 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2462 filters out names starting with '_' as before. Whether or not
2463 __all__ exists, there's no restriction on the type of M.
2464
Guido van Rossumf61f1662001-01-10 20:13:55 +00002465- File objects have a new method, xreadlines(). This is the fastest
2466 way to iterate over all lines in a file:
2467
2468 for line in file.xreadlines():
2469 ...do something to line...
2470
2471 See the xreadlines module (mentioned below) for how to do this for
2472 other file-like objects.
2473
2474- Even if you don't use file.xreadlines(), you may expect a speedup on
2475 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002476 quite a bit in platform-specific ways: on systems (like Linux) that
2477 support flockfile(), getc_unlocked(), and funlockfile(), those are
2478 used by default. On systems (like Windows) without getc_unlocked(),
2479 a complicated (but still thread-safe) method using fgets() is used by
2480 default.
2481
Tim Petersd52269b2001-01-25 06:23:18 +00002482 You can force use of the fgets() method by #define'ing
2483 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002484 getc_unlocked()).
2485
Tim Petersd52269b2001-01-25 06:23:18 +00002486 You can force fgets() not to be used by #define'ing
2487 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002488 test_bufio.py fails -- and let us know if it does!).
2489
2490- In addition, the fileinput module, while still slower than the other
2491 methods on most platforms, has been sped up too, by using
2492 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002493
2494- Support for run-time warnings has been added, including a new
2495 command line option (-W) to specify the disposition of warnings.
2496 See the description of the warnings module below.
2497
2498- Extensive changes have been made to the coercion code. This mostly
2499 affects extension modules (which can now implement mixed-type
2500 numerical operators without having to use coercion), but
2501 occasionally, in boundary cases the coercion semantics have changed
2502 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002503 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002504 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002505 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002506
Guido van Rossumf98eda02001-01-17 15:54:45 +00002507- In connection with the coercion changes, a new built-in singleton
2508 object, NotImplemented is defined. This can be returned for
2509 operations that wish to indicate they are not implemented for a
2510 particular combination of arguments. From C, this is
2511 Py_NotImplemented.
2512
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002513- The interpreter accepts now bytecode files on the command line even
2514 if they do not have a .pyc or .pyo extension. On Linux, after executing
2515
Martin v. Löwise214baa2001-02-04 22:37:56 +00002516import imp,sys,string
2517magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2518reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2519open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002520
2521 any byte code file can be used as an executable (i.e. as an argument
2522 to execve(2)).
2523
Tim Peters9940b802000-12-01 07:59:35 +00002524- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002525 character. In 1.6 and earlier, they never produced a sign,
2526 and raised an error if the value of the long was too large
2527 to fit in a Python int. In 2.0, they produced a sign if and
2528 only if too large to fit in an int. This was inconsistent
2529 across platforms (because the size of an int varies across
2530 platforms), and inconsistent with hex() and oct(). Example:
2531
2532 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002533 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002534 'ffffffbe' # in 2.0 and before, on 32-bit machines
2535 >>> hex(-0x42L)
2536 '-0x42L' # in all versions of Python
2537
Tim Peters9940b802000-12-01 07:59:35 +00002538 The behavior of %d formats for negative Python longs remains
2539 the same as in 2.0 (although in 1.6 and before, they raised
2540 an error if the long didn't fit in a Python int).
2541
2542 %u formats don't make sense for Python longs, but are allowed
2543 and treated the same as %d in 2.1. In 2.0, a negative long
2544 formatted via %u produced a sign if and only if too large to
2545 fit in an int. In 1.6 and earlier, a negative long formatted
2546 via %u raised an error if it was too big to fit in an int.
2547
Guido van Rossum3661d392000-12-12 22:10:31 +00002548- Dictionary objects have an odd new method, popitem(). This removes
2549 an arbitrary item from the dictionary and returns it (in the form of
2550 a (key, value) pair). This can be useful for algorithms that use a
2551 dictionary as a bag of "to do" items and repeatedly need to pick one
2552 item. Such algorithms normally end up running in quadratic time;
2553 using popitem() they can usually be made to run in linear time.
2554
Tim Peters36cdad12000-12-29 02:06:45 +00002555Standard library
2556
Thomas Woutersfe385252001-01-19 23:16:56 +00002557- In the time module, the time argument to the functions strftime,
2558 localtime, gmtime, asctime and ctime is now optional, defaulting to
2559 the current time (in the local timezone).
2560
Guido van Rossumda91f222001-01-15 16:36:08 +00002561- The ftplib module now defaults to passive mode, which is deemed a
2562 more useful default given that clients are often inside firewalls
2563 these days. Note that this could break if ftplib is used to connect
2564 to a *server* that is inside a firewall, from outside; this is
2565 expected to be a very rare situation. To fix that, you can call
2566 ftp.set_pasv(0).
2567
Martin v. Löwis10a27872001-01-13 09:54:41 +00002568- The module site now treats .pth files not only for path configuration,
2569 but also supports extensions to the initialization code: Lines starting
2570 with import are executed.
2571
Guido van Rossumf61f1662001-01-10 20:13:55 +00002572- There's a new module, warnings, which implements a mechanism for
2573 issuing and filtering warnings. There are some new built-in
2574 exceptions that serve as warning categories, and a new command line
2575 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2576 turns warnings into errors). warnings.warn(message[, category])
2577 issues a warning message; this can also be called from C as
2578 PyErr_Warn(category, message).
2579
2580- A new module xreadlines was added. This exports a single factory
2581 function, xreadlines(). The intention is that this code is the
2582 absolutely fastest way to iterate over all lines in an open
2583 file(-like) object:
2584
2585 import xreadlines
2586 for line in xreadlines.xreadlines(file):
2587 ...do something to line...
2588
2589 This is equivalent to the previous the speed record holder using
2590 file.readlines(sizehint). Note that if file is a real file object
2591 (as opposed to a file-like object), this is equivalent:
2592
2593 for line in file.xreadlines():
2594 ...do something to line...
2595
Tim Peters36cdad12000-12-29 02:06:45 +00002596- The bisect module has new functions bisect_left, insort_left,
2597 bisect_right and insort_right. The old names bisect and insort
2598 are now aliases for bisect_right and insort_right. XXX_right
2599 and XXX_left methods differ in what happens when the new element
2600 compares equal to one or more elements already in the list: the
2601 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002602 right. Code that doesn't care where equal elements end up should
2603 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002604
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002605- The new curses.panel module wraps the panel library that forms part
2606 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2607
Guido van Rossumf61f1662001-01-10 20:13:55 +00002608- The SocketServer module now sets the allow_reuse_address flag by
2609 default in the TCPServer class.
2610
2611- A new function, sys._getframe(), returns the stack frame pointer of
2612 the caller. This is intended only as a building block for
2613 higher-level mechanisms such as string interpolation.
2614
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002615- The pyexpat module supports a number of new handlers, which are
2616 available only in expat 1.2. If invocation of a callback fails, it
2617 will report an additional frame in the traceback. Parser objects
2618 participate now in garbage collection. If expat reports an unknown
2619 encoding, pyexpat will try to use a Python codec; that works only
2620 for single-byte charsets. The parser type objects is exposed as
2621 XMLParserObject.
2622
2623- xml.dom now offers standard definitions for symbolic node type and
2624 exception code constants, and a hierarchy of DOM exceptions. minidom
2625 was adjusted to use them.
2626
2627- The conformance of xml.dom.minidom to the DOM specification was
2628 improved. It detects a number of additional error cases; the
2629 previous/next relationship works even when the tree is modified;
2630 Node supports the normalize() method; NamedNodeMap, DocumentType and
2631 DOMImplementation classes were added; Element supports the
2632 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2633 method.
2634
Guido van Rossumf61f1662001-01-10 20:13:55 +00002635Build issues
2636
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002637- For Unix (and Unix-compatible) builds, configuration and building of
2638 extension modules is now greatly automated. Rather than having to
2639 edit the Modules/Setup file to indicate which modules should be
2640 built and where their include files and libraries are, a
2641 distutils-based setup.py script now takes care of building most
2642 extension modules. All extension modules built this way are built
2643 as shared libraries. Only a few modules that must be linked
2644 statically are still listed in the Setup file; you won't need to
2645 edit their configuration.
2646
2647- Python should now build out of the box on Cygwin. If it doesn't,
2648 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002649
2650- Python now always uses its own (renamed) implementation of getopt()
2651 -- there's too much variation among C library getopt()
2652 implementations.
2653
2654- C++ compilers are better supported; the CXX macro is always set to a
2655 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002656
Tim Petersd92dfe02000-12-12 01:18:41 +00002657Windows changes
2658
2659- select module: By default under Windows, a select() call
2660 can specify no more than 64 sockets. Python now boosts
2661 this Microsoft default to 512. If you need even more than
2662 that, see the MS docs (you'll need to #define FD_SETSIZE
2663 and recompile Python from source).
2664
Guido van Rossumf61f1662001-01-10 20:13:55 +00002665- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2666 subdirectory is no more!
2667
Tim Petersa3a3a032000-11-30 05:22:44 +00002668
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002669What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002670=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002671
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002672Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002673changes are in the file HISTORY. If you are making the jump directly
2674from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2675HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002676
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002677Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2678the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2679http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002680
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002681--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002682
2683======================================================================
2684
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002685What's new in 2.0 (since release candidate 1)?
2686==============================================
2687
2688Standard library
2689
2690- The copy_reg module was modified to clarify its intended use: to
2691 register pickle support for extension types, not for classes.
2692 pickle() will raise a TypeError if it is passed a class.
2693
2694- Fixed a bug in gettext's "normalize and expand" code that prevented
2695 it from finding an existing .mo file.
2696
2697- Restored support for HTTP/0.9 servers in httplib.
2698
Tim Peters989b7b92000-10-16 20:24:53 +00002699- The math module was changed to stop raising OverflowError in case of
2700 underflow, and return 0 instead in underflow cases. Whether Python
2701 used to raise OverflowError in case of underflow was platform-
2702 dependent (it did when the platform math library set errno to ERANGE
2703 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002704
2705- Fixed a bug in StringIO that occurred when the file position was not
2706 at the end of the file and write() was called with enough data to
2707 extend past the end of the file.
2708
2709- Fixed a bug that caused Tkinter error messages to get lost on
2710 Windows. The bug was fixed by replacing direct use of
2711 interp->result with Tcl_GetStringResult(interp).
2712
2713- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2714 redirect response.
2715
2716- Several changes were made to distutils: Some debugging code was
2717 removed from util. Fixed the installer used when an external zip
2718 program (like WinZip) is not found; the source code for this
2719 installer is in Misc/distutils. check_lib() was modified to behave
2720 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2721 test for whether installed modules are on sys.path was changed to
2722 use both normcase() and normpath().
2723
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002724- Several minor bugs were fixed in the xml package (the minidom,
2725 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002726
2727- The regression test driver (regrtest.py) behavior when invoked with
2728 -l changed: It now reports a count of objects that are recognized as
2729 garbage but not freed by the garbage collector.
2730
Tim Peters989b7b92000-10-16 20:24:53 +00002731- The regression test for the math module was changed to test
2732 exceptional behavior when the test is run in verbose mode. Python
2733 cannot yet guarantee consistent exception behavior across platforms,
2734 so the exception part of test_math is run only in verbose mode, and
2735 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002736
2737Internals
2738
2739- PyOS_CheckStack() has been disabled on Win64, where it caused
2740 test_sre to fail.
2741
2742Build issues
2743
2744- Changed compiler flags, so that gcc is always invoked with -Wall and
2745 -Wstrict-prototypes. Users compiling Python with GCC should see
2746 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002747 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002748 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002749
Tim Petersa3a3a032000-11-30 05:22:44 +00002750- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002751
2752Tools and other miscellany
2753
2754- The compiler in Tools/compiler was updated to support the new
2755 language features introduced in 2.0: extended print statement, list
2756 comprehensions, and augmented assignments. The new compiler should
2757 also be backwards compatible with Python 1.5.2; the compiler will
2758 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002759 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002760
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002761What's new in 2.0 release candidate 1 (since beta 2)?
2762=====================================================
2763
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002764What is release candidate 1?
2765
2766We believe that release candidate 1 will fix all known bugs that we
2767intend to fix for the 2.0 final release. This release should be a bit
2768more stable than the previous betas. We would like to see even more
2769widespread testing before the final release, so we are producing this
2770release candidate. The final release will be exactly the same unless
2771any show-stopping (or brown bag) bugs are found by testers of the
2772release candidate.
2773
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002774All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002775to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002776
2777Core language, builtins, and interpreter
2778
2779- A bug that caused crashes when __coerce__ was used with augmented
2780 assignment, e.g. +=, was fixed.
2781
2782- Raise ZeroDivisionError when raising zero to a negative number,
2783 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2784 power operator and the result of math.pow(0.0, -2.0) will vary by
2785 platform. On Linux, it raises a ValueError.
2786
2787- A bug in Unicode string interpolation was fixed that occasionally
2788 caused errors with formats including "%%". For example, the
2789 following expression "%% %s" % u"abc" no longer raises a TypeError.
2790
2791- Compilation of deeply nested expressions raises MemoryError instead
2792 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2793
2794- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2795 rendering them useless. They are now written in binary mode again.
2796
2797Standard library
2798
2799- Keyword arguments are now accepted for most pattern and match object
2800 methods in SRE, the standard regular expression engine.
2801
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002802- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002803 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002804
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002805- Several bugs in the Unicode handling and error handling in _tkinter
2806 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002807
2808- Fix memory management errors in Merge() and Tkapp_Call() routines.
2809
2810- Several changes were made to cStringIO to make it compatible with
2811 the file-like object interface and with StringIO. If operations are
2812 performed on a closed object, an exception is raised. The truncate
2813 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002814 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002815
2816- There were many changes made to the linuxaudiodev module and its
2817 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002818 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002819
2820 Note that this module is named poorly, because it should work
2821 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002822 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002823
2824 The module now raises exceptions when errors occur instead of
2825 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2826 audio) and defines a getptr() method that calls the
2827 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2828
2829- The library_version attribute, introduced in an earlier beta, was
2830 removed because it can not be supported with early versions of the C
2831 readline library, which provides no way to determine the version at
2832 compile-time.
2833
2834- The binascii module is now enabled on Win64.
2835
Tim Peters46446d62000-10-09 21:19:31 +00002836- tokenize.py no longer suffers "recursion depth" errors when parsing
2837 programs with very long string literals.
2838
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002839Internals
2840
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002841- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002842 which is called when the interpreter starts up to determine where
2843 the standard library is installed. These vulnerabilities affect all
2844 previous versions of Python and can be exploited by setting very
2845 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2846 setuid Python script, although use of the wrapper in
2847 Misc/setuid-prog.c will eliminate the vulnerability.
2848
2849- Fixed garbage collection bugs in instance creation that were
2850 triggered when errors occurred during initialization. The solution,
2851 applied in cPickle and in PyInstance_New(), is to call
2852 PyObject_GC_Init() after the initialization of the object's
2853 container attributes is complete.
2854
2855- pyexpat adds definitions of PyModule_AddStringConstant and
2856 PyModule_AddObject if the Python version is less than 2.0, which
2857 provides compatibility with PyXML on Python 1.5.2.
2858
2859- If the platform has a bogus definition for LONG_BIT (the number of
2860 bits in a long), an error will be reported at compile time.
2861
2862- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2863 collection crashes and possibly other, unreported crashes.
2864
2865- Fixed a memory leak in _PyUnicode_Fini().
2866
2867Build issues
2868
2869- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002870 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002871 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002872
2873- The mmap.PAGESIZE constant is now initialized using sysconf when
2874 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2875
2876- The md5 file should now compile on all platforms.
2877
2878- The select module now compiles on platforms that do not define
2879 POLLRDNORM and related constants.
2880
2881- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002882 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002883
Jeremy Hylton10921202000-10-09 18:34:12 +00002884- BeOS: A number of changes were made to the build and installation
2885 process. ar-fake now operates on a directory of object files.
2886 dl_export.h is gone, and its macros now appear on the mwcc command
2887 line during build on PPC BeOS.
2888
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002889- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002890 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002891
2892- Cygwin: Support for shared libraries, Tkinter, and sockets.
2893
2894- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2895
2896Tools and other miscellany
2897
2898- Removed debugging prints from main used with freeze.
2899
Tim Peters46446d62000-10-09 21:19:31 +00002900- IDLE auto-indent no longer crashes when it encounters Unicode
2901 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002902
2903What's new in 2.0 beta 2 (since beta 1)?
2904========================================
2905
2906Core language, builtins, and interpreter
2907
Tim Peters482c0212000-09-26 06:33:09 +00002908- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002909 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002910
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002911- Add -h and -V command line options to print the usage message and
2912 Python version number and exit immediately.
2913
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002914- eval() and exec accept Unicode objects as code parameters.
2915
2916- getattr() and setattr() now also accept Unicode objects for the
2917 attribute name, which are converted to strings using the default
2918 encoding before lookup.
2919
2920- Multiplication on string and Unicode now does proper bounds
2921 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2922 string is too long."
2923
2924- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002925 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002926
Jeremy Hylton1b618592000-09-26 05:32:36 +00002927
2928Standard library and extensions
2929
Guido van Rossum5b08f132001-04-16 02:05:23 +00002930- socket module: the OpenSSL code now adds support for RAND_status()
2931 and EGD (Entropy Gathering Device).
2932
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002933- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002934 argument checking; it still takes no arguments.
2935
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002936- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002937
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002938- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002939
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002940- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002941
2942- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002943 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002944
2945- copy: Copy Unicode objects atomically.
2946
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002947- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002948
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002949- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002950
Fred Drake67233bc2000-09-26 16:40:27 +00002951- dbm: Add get() and setdefault() methods to dbm object. Add constant
2952 `library' to module that names the library used. Added doc strings
2953 and method names to error messages. Uses configure to determine
2954 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2955 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002956
2957- distutils: Update to version 0.9.3.
2958
2959- dl: Add several dl.RTLD_ constants.
2960
2961- fpectl: Now supported on FreeBSD.
2962
2963- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2964 found by the collector will be saved in gc.garbage. This is useful
2965 for debugging a program that creates reference cycles.
2966
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002967- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002968 of HTTP class. Do not close socket on zero-length response. Do not
2969 crash when server sends invalid content-length header.
2970
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002971- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002972
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002973- marshal: When reading a short, sign-extend on platforms where shorts
2974 are bigger than 16 bits. When reading a long, repair the unportable
2975 sign extension that was being done for 64-bit machines. (It assumed
2976 that signed right shift sign-extends.)
2977
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002978- operator: Add contains(), invert(), __invert__() as aliases for
2979 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002980
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002981- os: Add support for popen2() and popen3() on all platforms where
2982 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002983
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002984- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002985 clicking on a file in Explorer (or passing the file name to the
2986 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002987
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002988- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002989 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002990
2991- pickle: Now raises ValueError when an invalid pickle that contains
2992 a non-string repr where a string repr was expected. This behavior
2993 matches cPickle.
2994
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002995- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002996
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002997- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002998
2999- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003000 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003001 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003002
3003- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003004 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003005
3006- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003007 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003008 few cycles during startup since the first call to
3009 setdefaultencoding() will initialize the codec registry and the
3010 encodings package.
3011
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003012- socket: Support for size hint in readlines() method of object returned
3013 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003014
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003015- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003016 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003017 is followed by whitespace.
3018
Tim Petersa3a3a032000-11-30 05:22:44 +00003019- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003020
3021- struct: Check ranges for bytes and shorts.
3022
3023- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003024 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003025
3026- Tkinter: Image objects are now guaranteed to have unique ids. Set
3027 event.delta to zero if Tk version doesn't support mousewheel.
3028 Removed some debugging prints.
3029
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003030- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003031
Fred Drake67233bc2000-09-26 16:40:27 +00003032- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003033 which works around a bug in Norton AntiVirus 2000 that leads directly
3034 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003035
3036- xml: New version detection code allows PyXML to override standard
3037 XML package if PyXML version is greater than 0.6.1.
3038
Fred Drake64bb3802000-09-26 16:21:35 +00003039- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3040 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3041 tree only for nodes which are sufficiently interesting to a specific
3042 application. Does not provide the HTML-specific extensions. Still
3043 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003044
Fred Drake64bb3802000-09-26 16:21:35 +00003045- xml.sax: SAX 2 support for Python, including all the handler
3046 interfaces needed to process XML 1.0 compliant XML. Some
3047 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003048
Fred Drake64bb3802000-09-26 16:21:35 +00003049- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3050 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003051
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003052
Jeremy Hylton1b618592000-09-26 05:32:36 +00003053C API
3054
3055- Add three new convenience functions for module initialization --
3056 PyModule_AddObject(), PyModule_AddIntConstant(), and
3057 PyModule_AddStringConstant().
3058
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003059- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003060 removed and add #error to Python.h if NULL isn't defined after
3061 #include of stdio.h.
3062
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003063- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003064 backwards compatibility (at the source level) with old extensions.
3065
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003066- A wrapper API was added for signal() and sigaction(). Instead of
3067 either function, always use PyOS_getsig() to get a signal handler
3068 and PyOS_setsig() to set one. A new convenience typedef
3069 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003070
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003071- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003072 internal data buffer and size of a string object -- or the default
3073 encoded version of a Unicode object.
3074
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003075- PyString_Size() and PyString_AsString() accept Unicode objects.
3076
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003077- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003078 exists). INT_MAX and LONG_MAX will always be defined, even if
3079 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003080
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003081- PyFloat_FromString takes a second argument, pend, that was
3082 effectively useless. It is now officially useless but preserved for
3083 backwards compatibility. If the pend argument is not NULL, *pend is
3084 set to NULL.
3085
3086- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3087 for the attribute name. See note on getattr() above.
3088
3089- A few bug fixes to argument processing for Unicode.
3090 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3091 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3092 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003093 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003094
3095- Py_BuildValue accepts B format (for bgen-generated code).
3096
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003097
Jeremy Hylton1b618592000-09-26 05:32:36 +00003098Internals
3099
3100- On Unix, fix code for finding Python installation directory so that
3101 it works when argv[0] is a relative path.
3102
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003103- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003104 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003105 rather than by generating a copy of the object.
3106
Tim Peters482c0212000-09-26 06:33:09 +00003107- Several of the internal Unicode tables are much smaller now, and
3108 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003109
Jeremy Hylton97693b02000-09-26 17:42:51 +00003110- In the garbage collector: Fixed bug in collection of tuples. Fixed
3111 bug that caused some instances to be removed from the container set
3112 while they were still live. Fixed parsing in gc.set_debug() for
3113 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003114
3115- Fixed refcount problem in instance deallocation that only occurred
3116 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3117
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003118- On Windows, getpythonregpath is now protected against null data in
3119 registry key.
3120
3121- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003122 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003123
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003124
Jeremy Hylton1b618592000-09-26 05:32:36 +00003125Build and platform-specific issues
3126
3127- Better support of GNU Pth via --with-pth configure option.
3128
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003129- Python/C API now properly exposed to dynamically-loaded extension
3130 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003131
3132- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3133 Don't define MS_SYNC to be zero when it is undefined. Added missing
3134 prototypes in posixmodule.c.
3135
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003136- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003137 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003138
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003139- Fix largefile support on older NetBSD systems and OpenBSD by adding
3140 define for TELL64.
3141
3142
3143Tools and other miscellany
3144
3145- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3146
3147- freeze: The modulefinder now works with 2.0 opcodes.
3148
Tim Petersa3a3a032000-11-30 05:22:44 +00003149- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003150 Move hackery of sys.argv until after the Tk instance has been
3151 created, which allows the application-specific Tkinter
3152 initialization to be executed if present; also pass an explicit
3153 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003154
Jeremy Hylton1b618592000-09-26 05:32:36 +00003155
3156What's new in 2.0 beta 1?
3157=========================
3158
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003159Source Incompatibilities
3160------------------------
3161
3162None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3163such as single-argument append(), connect() and bind(), and changes to
3164str(long) and repr(float).
3165
3166
3167Binary Incompatibilities
3168------------------------
3169
3170- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3171with Python 2.0; these extensions will have to be rebuilt for Python
31722.0.
3173
3174- On Windows, attempting to import a third party extension built for
3175Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3176can do about this. Check your PYTHONPATH environment variable!
3177
3178- Python bytecode files (*.pyc and *.pyo) are not compatible between
3179releases.
3180
3181
3182Overview of Changes Since 1.6
3183-----------------------------
3184
3185There are many new modules (including brand new XML support through
3186the xml package, and i18n support through the gettext module); a list
3187of all new modules is included below. Lots of bugs have been fixed.
3188
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003189The process for making major new changes to the language has changed
3190since Python 1.6. Enhancements must now be documented by a Python
3191Enhancement Proposal (PEP) before they can be accepted.
3192
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003193There are several important syntax enhancements, described in more
3194detail below:
3195
3196 - Augmented assignment, e.g. x += 1
3197
3198 - List comprehensions, e.g. [x**2 for x in range(10)]
3199
3200 - Extended import statement, e.g. import Module as Name
3201
3202 - Extended print statement, e.g. print >> file, "Hello"
3203
3204Other important changes:
3205
3206 - Optional collection of cyclical garbage
3207
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003208Python Enhancement Proposal (PEP)
3209---------------------------------
3210
3211PEP stands for Python Enhancement Proposal. A PEP is a design
3212document providing information to the Python community, or describing
3213a new feature for Python. The PEP should provide a concise technical
3214specification of the feature and a rationale for the feature.
3215
3216We intend PEPs to be the primary mechanisms for proposing new
3217features, for collecting community input on an issue, and for
3218documenting the design decisions that have gone into Python. The PEP
3219author is responsible for building consensus within the community and
3220documenting dissenting opinions.
3221
3222The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003223
3224Augmented Assignment
3225--------------------
3226
3227This must have been the most-requested feature of the past years!
3228Eleven new assignment operators were added:
3229
Guido van Rossume905e952000-09-05 12:42:46 +00003230 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003231
3232For example,
3233
3234 A += B
3235
3236is similar to
3237
3238 A = A + B
3239
3240except that A is evaluated only once (relevant when A is something
3241like dict[index].attr).
3242
3243However, if A is a mutable object, A may be modified in place. Thus,
3244if A is a number or a string, A += B has the same effect as A = A+B
3245(except A is only evaluated once); but if a is a list, A += B has the
3246same effect as A.extend(B)!
3247
3248Classes and built-in object types can override the new operators in
3249order to implement the in-place behavior; the not-in-place behavior is
3250used automatically as a fallback when an object doesn't implement the
3251in-place behavior. For classes, the method name is derived from the
3252method name for the corresponding not-in-place operator by inserting
3253an 'i' in front of the name, e.g. __iadd__ implements in-place
3254__add__.
3255
3256Augmented assignment was implemented by Thomas Wouters.
3257
3258
3259List Comprehensions
3260-------------------
3261
3262This is a flexible new notation for lists whose elements are computed
3263from another list (or lists). The simplest form is:
3264
3265 [<expression> for <variable> in <sequence>]
3266
Guido van Rossum56db0952000-09-06 23:34:25 +00003267For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003268This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003269
3270You can also add a condition:
3271
3272 [<expression> for <variable> in <sequence> if <condition>]
3273
3274For example, [w for w in words if w == w.lower()] would yield the list
3275of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003276than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003277
3278You can also have nested for loops and more than one 'if' clause. For
3279example, here's a function that flattens a sequence of sequences::
3280
3281 def flatten(seq):
3282 return [x for subseq in seq for x in subseq]
3283
3284 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3285
3286This prints
3287
3288 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3289
3290List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003291Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003292
3293
3294Extended Import Statement
3295-------------------------
3296
3297Many people have asked for a way to import a module under a different
3298name. This can be accomplished like this:
3299
3300 import foo
3301 bar = foo
3302 del foo
3303
3304but this common idiom gets old quickly. A simple extension of the
3305import statement now allows this to be written as follows:
3306
3307 import foo as bar
3308
3309There's also a variant for 'from ... import':
3310
3311 from foo import bar as spam
3312
3313This also works with packages; e.g. you can write this:
3314
3315 import test.regrtest as regrtest
3316
3317Note that 'as' is not a new keyword -- it is recognized only in this
3318context (this is only possible because the syntax for the import
3319statement doesn't involve expressions).
3320
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003321Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003322
3323
3324Extended Print Statement
3325------------------------
3326
3327Easily the most controversial new feature, this extension to the print
3328statement adds an option to make the output go to a different file
3329than the default sys.stdout.
3330
3331For example, to write an error message to sys.stderr, you can now
3332write:
3333
3334 print >> sys.stderr, "Error: bad dog!"
3335
3336As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003337evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003338
3339 print >> None, "Hello world"
3340
3341is equivalent to
3342
3343 print "Hello world"
3344
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003345Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003346
3347
3348Optional Collection of Cyclical Garbage
3349---------------------------------------
3350
3351Python is now equipped with a garbage collector that can hunt down
3352cyclical references between Python objects. It's no replacement for
3353reference counting; in fact, it depends on the reference counts being
3354correct, and decides that a set of objects belong to a cycle if all
3355their reference counts can be accounted for from their references to
3356each other. This devious scheme was first proposed by Eric Tiedemann,
3357and brought to implementation by Neil Schemenauer.
3358
3359There's a module "gc" that lets you control some parameters of the
3360garbage collection. There's also an option to the configure script
3361that lets you enable or disable the garbage collection. In 2.0b1,
3362it's on by default, so that we (hopefully) can collect decent user
3363experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003364performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003365off by default in the final 2.0 release.
3366
3367
3368Smaller Changes
3369---------------
3370
3371A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3372map(None, seq1, seq2, ...) when the sequences have the same length;
3373i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3374the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003375zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003376
3377sys.version_info is a tuple (major, minor, micro, level, serial).
3378
3379Dictionaries have an odd new method, setdefault(key, default).
3380dict.setdefault(key, default) returns dict[key] if it exists; if not,
3381it sets dict[key] to default and returns that value. Thus:
3382
3383 dict.setdefault(key, []).append(item)
3384
3385does the same work as this common idiom:
3386
3387 if not dict.has_key(key):
3388 dict[key] = []
3389 dict[key].append(item)
3390
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003391There are two new variants of SyntaxError that are raised for
3392indentation-related errors: IndentationError and TabError.
3393
3394Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3395escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003396
3397The limits on the size of expressions and file in Python source code
3398have been raised from 2**16 to 2**32. Previous versions of Python
3399were limited because the maximum argument size the Python VM accepted
3400was 2**16. This limited the size of object constructor expressions,
3401e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3402limit was raised thanks to a patch by Charles Waldman that effectively
3403fixes the problem. It is now much more likely that you will be
3404limited by available memory than by an arbitrary limit in Python.
3405
3406The interpreter's maximum recursion depth can be modified by Python
3407programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3408limit is the maximum number of recursive calls that can be made by
3409Python code. The limit exists to prevent infinite recursion from
3410overflowing the C stack and causing a core dump. The default value is
34111000. The maximum safe value for a particular platform can be found
3412by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003413
3414New Modules and Packages
3415------------------------
3416
3417atexit - for registering functions to be called when Python exits.
3418
3419imputil - Greg Stein's alternative API for writing custom import
3420hooks.
3421
3422pyexpat - an interface to the Expat XML parser, contributed by Paul
3423Prescod.
3424
3425xml - a new package with XML support code organized (so far) in three
3426subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3427would fill a volume. There's a special feature whereby a
3428user-installed package named _xmlplus overrides the standard
3429xmlpackage; this is intended to give the XML SIG a hook to distribute
3430backwards-compatible updates to the standard xml package.
3431
3432webbrowser - a platform-independent API to launch a web browser.
3433
3434
Guido van Rossume905e952000-09-05 12:42:46 +00003435Changed Modules
3436---------------
3437
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003438array -- new methods for array objects: count, extend, index, pop, and
3439remove
3440
3441binascii -- new functions b2a_hex and a2b_hex that convert between
3442binary data and its hex representation
3443
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003444calendar -- Many new functions that support features including control
3445over which day of the week is the first day, returning strings instead
3446of printing them. Also new symbolic constants for days of week,
3447e.g. MONDAY, ..., SUNDAY.
3448
3449cgi -- FieldStorage objects have a getvalue method that works like a
3450dictionary's get method and returns the value attribute of the object.
3451
3452ConfigParser -- The parser object has new methods has_option,
3453remove_section, remove_option, set, and write. They allow the module
3454to be used for writing config files as well as reading them.
3455
3456ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003457optionally support the RFC 959 REST command.
3458
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003459gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003460
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003461httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3462the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003463
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003464locale -- implement getdefaultlocale for Win32 and Macintosh
3465
3466marshal -- no longer dumps core when marshaling deeply nested or
3467recursive data structures
3468
3469os -- new functions isatty, seteuid, setegid, setreuid, setregid
3470
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003471os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3472support under Unix.
3473
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003474os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003475
3476os.path -- fix semantics of os.path.commonprefix
3477
3478smtplib -- support for sending very long messages
3479
3480socket -- new function getfqdn()
3481
3482readline -- new functions to read, write and truncate history files.
3483The readline section of the library reference manual contains an
3484example.
3485
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003486select -- add interface to poll system call
3487
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003488shutil -- new copyfileobj function
3489
3490SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3491HTTP server.
3492
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003493Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003494
3495urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003496e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003497
3498whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003499
3500
3501Obsolete Modules
3502----------------
3503
3504None. However note that 1.6 made a whole slew of modules obsolete:
3505stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3506poly, zmod, strop, util, whatsound.
3507
3508
3509Changed, New, Obsolete Tools
3510----------------------------
3511
Tim Peters8b092332000-09-05 20:15:25 +00003512None.
Guido van Rossume905e952000-09-05 12:42:46 +00003513
3514
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003515C-level Changes
3516---------------
3517
3518Several cleanup jobs were carried out throughout the source code.
3519
3520All C code was converted to ANSI C; we got rid of all uses of the
3521Py_PROTO() macro, which makes the header files a lot more readable.
3522
3523Most of the portability hacks were moved to a new header file,
3524pyport.h; several other new header files were added and some old
3525header files were removed, in an attempt to create a more rational set
3526of header files. (Few of these ever need to be included explicitly;
3527they are all included by Python.h.)
3528
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003529Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003530and Win64, especially for the new Intel Itanium processor. Mick also
3531added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003532
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003533The C APIs to return an object's size have been update to consistently
3534use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3535previous versions, the abstract interfaces used PyXXX_Length and the
3536concrete interfaces used PyXXX_Size. The old names,
3537e.g. PyObject_Length, are still available for backwards compatibility
3538at the API level, but are deprecated.
3539
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003540The PyOS_CheckStack function has been implemented on Windows by
3541Fredrik Lundh. It prevents Python from failing with a stack overflow
3542on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003543
3544The GC changes resulted in creation of two new slots on object,
3545tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003546the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003547
3548The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003549C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003550
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003551PyErr_Format has been updated to automatically calculate the size of
3552the buffer needed to hold the formatted result string. This change
3553prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003554
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003555New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003556
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003557PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3558that are the same as their non-Ex counterparts except they take an
3559extra flag argument that tells them to close the file when done.
3560
3561XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003562
Tim Peters8b092332000-09-05 20:15:25 +00003563
3564Windows Changes
3565---------------
3566
3567New popen2/popen3/peopen4 in os module (see Changed Modules above).
3568
3569os.popen is much more usable on Windows 95 and 98. See Microsoft
3570Knowledge Base article Q150956. The Win9x workaround described there
3571is implemented by the new w9xpopen.exe helper in the root of your
3572Python installation. Note that Python uses this internally; it is not
3573a standalone program.
3574
3575Administrator privileges are no longer required to install Python
3576on Windows NT or Windows 2000. If you have administrator privileges,
3577Python's registry info will be written under HKEY_LOCAL_MACHINE.
3578Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003579under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003580uses of Python, but will prevent some advanced uses from working
3581(for example, running a Python script as an NT service, or possibly
3582from CGI).
3583
3584[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3585installer; instead, it installs the needed Tcl/Tk files directly in the
3586Python directory. If you already have a Tcl/Tk installation, this
3587wastes some disk space (about 4 Megs) but avoids problems with
3588conflicting Tcl/Tk installations, and makes it much easier for Python
3589to ensure that Tcl/Tk can find all its files.
3590
3591[This was new in 1.6] The Windows installer now installs by default in
3592\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3593
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003594
3595Updates to the changes between 1.5.2 and 1.6
3596--------------------------------------------
3597
3598The 1.6 NEWS file can't be changed after the release is done, so here
3599is some late-breaking news:
3600
3601New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3602and changes to getlocale() and setlocale().
3603
3604The new module is now enabled per default.
3605
3606It is not true that the encodings codecs cannot be used for normal
3607strings: the string.encode() (which is also present on 8-bit strings
3608!) allows using them for 8-bit strings too, e.g. to convert files from
3609cp1252 (Windows) to latin-1 or vice-versa.
3610
3611Japanese codecs are available from Tamito KAJIYAMA:
3612http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3613
3614
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003615======================================================================