blob: c8bda833f0d5436994b987a0acb8d364bac1419e [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
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000173- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
174 argument.
175
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000176- Some fixes in the copy module: when an object is copied through its
177 __reduce__ method, there was no check for a __setstate__ method on
178 the result [SF patch 565085]; deepcopy should treat instances of
179 custom metaclasses the same way it treats instances of type 'type'
180 [SF patch 560794].
181
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000182- Sockets now support timeout mode. After s.settimeout(T), where T is
183 a float expressing seconds, subsequent operations raise an exception
184 if they cannot be completed within T seconds. To disable timeout
185 mode, use s.settimeout(None).
186
187- getopt.gnu_getopt was added. This supports GNU-style option
188 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000189
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000190- Stop using strings for exceptions. String objects used for
191 exceptions are now classes deriving from Exception. The objects
192 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
193 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000194
Walter Dörwald474458d2002-06-04 15:16:29 +0000195- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
196 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
197 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
198 big endian systems were added to the codecs module. The old names
199 BOM32_* and BOM64_* were off by a factor of 2.
200
Guido van Rossumf9257822002-06-18 20:43:18 +0000201- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000202
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000203- ftplib.retrlines() now tests for callback is None rather than testing
204 for False. Was causing an error when given a callback object which
205 was callable but also returned len() as zero. The change may
206 create new breakage if the caller relied on the undocumented behavior
207 and called with callback set to [] or some other False value not
208 identical to None.
209
Tim Peters46c04e12002-05-05 20:40:00 +0000210- random.gauss() uses a piece of hidden state used by nothing else,
211 and the .seed() and .whseed() methods failed to reset it. In other
212 words, setting the seed didn't completely determine the sequence of
213 results produced by random.gauss(). It does now. Programs repeatedly
214 mixing calls to a seed method with calls to gauss() may see different
215 results now.
216
Fred Drake7f781c92002-05-01 20:33:53 +0000217- The pickle.Pickler class grew a clear_memo() method to mimic that
218 provided by cPickle.Pickler.
219
Tim Peters81b92512002-04-29 01:37:32 +0000220- difflib's SequenceMatcher class now does a dynamic analysis of
221 which elements are so frequent as to constitute noise. For
222 comparing files as sequences of lines, this generally works better
223 than the IS_LINE_JUNK function, and function ndiff's linejunk
224 argument defaults to None now as a result. A happy benefit is
225 that SequenceMatcher may run much faster now when applied
226 to large files with many duplicate lines (for example, C program
227 text with lots of repeated "}" and "return NULL;" lines).
228
Guido van Rossum256705b2002-04-23 13:29:43 +0000229- New Text.dump() method in Tkinter module.
230
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000231- New distutils commands for building packagers were added to
232 support pkgtool on Solaris and swinstall on HP-UX.
233
234- distutils now has a new abstract binary packager base class
235 command/bdist_packager, which simplifies writing packagers.
236 This will hopefully provide the missing bits to encourage
237 people to submit more packagers, e.g. for Debian, FreeBSD
238 and other systems.
239
Guido van Rossumf9257822002-06-18 20:43:18 +0000240- The UTF-16, -LE and -BE stream readers now raise a
241 NotImplementedError for all calls to .readline(). Previously, they
242 used to just produce garbage or fail with an encoding error --
243 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 +0000244 work well with these.
245
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000246- compileall now supports quiet operation.
247
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000248- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000249 connections.
250
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000251- socket module: the SSL support was broken out of the main
252 _socket module C helper and placed into a new _ssl helper
253 which now gets imported by socket.py if available and working.
254
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000255- encodings package: added aliases for all supported IANA character
256 sets
257
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000258- ftplib: to safeguard the user's privacy, anonymous login will use
259 "anonymous@" as default password, rather than the real user and host
260 name.
261
Fred Drake36736122002-01-10 13:50:31 +0000262- webbrowser: tightened up the command passed to os.system() so that
263 arbitrary shell code can't be executed because a bogus URL was
264 passed in.
265
Tim Peters11bd9942002-02-01 00:52:29 +0000266- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000267 gettext.find an optional all argument. Translations will now fallback
268 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000269
Martin v. Löwis9668b932002-01-12 11:27:42 +0000270- distutils bdist commands now offer a --skip-build option.
271
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000272- warnings.warn now accepts a Warning instance as first argument.
273
Fred Drakefed7e852002-04-04 19:36:15 +0000274- The xml.sax.expatreader.ExpatParser class will no longer create
275 circular references by using itself as the locator that gets passed
276 to the content handler implementation. [SF bug #535474]
277
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000278- The email.Parser.Parser class now properly parses strings regardless
279 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
280 or CRLF). Also, the Header class's constructor default arguments
281 has changed slightly so that an explicit maxlinelen value is always
282 honored.
283
Tim Petersaf8446f2001-12-21 21:36:50 +0000284Tools/Demos
285
Marc-André Lemburg46260092002-04-04 16:17:11 +0000286- freeze.py now produces binaries which can import shared modules,
287 unlike before when this failed due to missing symbol exports in
288 the generated binary.
289
Tim Petersaf8446f2001-12-21 21:36:50 +0000290Build
291
Tim Peters1de41bf2002-07-03 03:31:20 +0000292- Accoring to Annex F of the current C standard,
293
294 The Standard C macro HUGE_VAL and its float and long double analogs,
295 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
296 positive infinities.
297
298 Python only uses the double HUGE_VAL, and only to #define its own symbol
299 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
300 pyport.h used to try to worm around that, but the workarounds triggered
301 other bugs on other platforms, so we gave up. If your platform defines
302 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
303 that works on your platform. The only instance of this I'm sure about
304 is on an unknown subset of Cray systems, described here:
305
306 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
307
308 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
309
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000310- The configure option --without-doc-strings can be used to remove the
311 doc strings from the builtin functions and modules; this reduces the
312 size of the executable.
313
Tim Peters639295f2002-04-21 07:30:30 +0000314- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
315 say how or when to configure it, or how to turn it off.
316
Martin v. Löwis1142de32002-03-29 16:28:31 +0000317- On Unix, a shared libpython2.3.so can be created with --enable-shared.
318
Tim Peters8deda702002-03-30 10:06:07 +0000319- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
320 preprocessor symbols were eliminated. The internal decisions they
321 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000322
Fred Drake7d28b732002-05-02 21:17:00 +0000323- The tools used to build the documentation now work under Cygwin as
324 well as Unix.
325
Skip Montanaro57454e52002-06-14 20:30:31 +0000326- The bsddb and dbm module builds have been changed to try and avoid version
327 skew problems and disable linkage with Berkeley DB 1.85 unless the
328 installer knows what s/he's doing. See the section on building these
329 modules in the README file for details.
330
Tim Petersaf8446f2001-12-21 21:36:50 +0000331C API
332
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000333- Added new macro PySequence_ITEM(o, i) that directly calls
334 sq_item without rechecking that o is a sequence and without
335 adjusting for negative indices.
336
Fred Draked0ba6362002-05-02 21:28:26 +0000337- PyRange_New() now raises ValueError if the fourth argument is not 1.
338 This is part of the removal of deprecated features of the xrange
339 object.
340
Guido van Rossum517c7d42002-04-26 02:49:14 +0000341- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
342 coercion if both arguments have the same type but this type has the
343 CHECKTYPES flag set. This is to better support proxies.
344
Neil Schemenauer9344b142002-04-12 23:00:08 +0000345- The type of tp_free has been changed from "void (*)(PyObject *)" to
346 "void (*)(void *)".
347
348- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
349
Guido van Rossum0986d822002-04-08 01:38:42 +0000350- A type can now inherit its metatype from its base type. Previously,
351 when PyType_Ready() was called, if ob_type was found to be NULL, it
352 was always set to &PyType_Type; now it is set to base->ob_type,
353 where base is tp_base, defaulting to &PyObject_Type.
354
355- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
356
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000357- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000358
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000359- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000360 without going through the buffer API.
361
Martin v. Löwis7198a522002-01-01 19:59:11 +0000362- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
363
Tim Peters10a3bb52001-12-25 19:07:38 +0000364- An old #define of ANY as void has been removed from pyport.h. This
365 hasn't been used since Python's pre-ANSI days, and the #define has
366 been marked as obsolete since then. SF bug 495548 says it created
367 conflicts with other packages, so keeping it around wasn't harmless.
368
Tim Petersaf8446f2001-12-21 21:36:50 +0000369- Because Python's magic number scheme broke on January 1st, we decided
370 to stop Python development. Thanks for all the fish!
371
Tim Petersfb05db22002-03-11 00:24:00 +0000372- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000373 scheme to a new one. See Python/import.c for details.
374
Tim Petersaf8446f2001-12-21 21:36:50 +0000375New platforms
376
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000377- AtheOS is now supported.
378
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000379- GNU/Hurd is now supported.
380
Tim Petersaf8446f2001-12-21 21:36:50 +0000381Tests
382
383Windows
384
Tim Peters08e72952002-04-16 20:48:01 +0000385- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
386 of that has been fixed in the installer (disabled Wise's "delete in-
387 use files" uninstall option).
388
Guido van Rossum181e41a2002-04-06 00:23:25 +0000389- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
390
Tim Peters33187922002-04-04 20:02:04 +0000391- The installer now installs Start menu shortcuts under (the local
392 equivalent of) "All Users" when doing an Admin install.
393
Tim Petersfb05db22002-03-11 00:24:00 +0000394- file.truncate([newsize]) now works on Windows for all newsize values.
395 It used to fail if newsize didn't fit in 32 bits, reflecting a
396 limitation of MS _chsize (which is no longer used).
397
Tim Petersab034fa2002-02-01 11:27:43 +0000398- os.waitpid() is now implemented for Windows, and can be used to block
399 until a specified process exits. This is similar to, but not exactly
400 the same as, os.waitpid() on POSIX systems. If you're waiting for
401 a specific process whose pid was obtained from one of the spawn()
402 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000403 See the docs for details. The docs were changed to clarify that
404 spawn functions return, and waitpid requires, a process handle on
405 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000406
Tim Peters11bd9942002-02-01 00:52:29 +0000407- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000408 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000409 to a nasty problem: before 2.3, if you got a temp file on Windows, it
410 got wrapped in an object whose close() method first closed the
411 underlying file, then deleted the file. This usually worked fine.
412 However, the spawn family of functions on Windows create (at a low C
413 level) the same set of open files in the spawned process Q as were
414 open in the spawning process P. If a temp file f was among them, then
415 doing f.close() in P first closed P's C-level file handle on f, but Q's
416 C-level file handle on f remained open, so the attempt in P to delete f
417 blew up with a "Permission denied" error (Windows doesn't allow
418 deleting open files). This was surprising, subtle, and difficult to
419 work around.
420
421- The os module now exports all the symbolic constants usable with the
422 low-level os.open() on Windows: the new constants in 2.3 are
423 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
424 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
425 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
426 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
427 (so specify both if you want both; note that neither is useful unless
428 specified with O_CREAT too).
429
Tim Petersaf8446f2001-12-21 21:36:50 +0000430Mac
431
432
Tim Peters909c0912001-12-14 23:16:18 +0000433What's New in Python 2.2 final?
434Release date: 21-Dec-2001
435===============================
436
437Type/class unification and new-style classes
438
Barry Warsaw52acb492001-12-21 20:04:22 +0000439- pickle.py, cPickle: allow pickling instances of new-style classes
440 with a custom metaclass.
441
Tim Peters909c0912001-12-14 23:16:18 +0000442Core and builtins
443
Barry Warsaw52acb492001-12-21 20:04:22 +0000444- weakref proxy object: when comparing, unwrap both arguments if both
445 are proxies.
446
Tim Peters909c0912001-12-14 23:16:18 +0000447Extension modules
448
Barry Warsaw52acb492001-12-21 20:04:22 +0000449- binascii.b2a_base64(): fix a potential buffer overrun when encoding
450 very short strings.
451
452- cPickle: the obscure "fast" mode was suspected of causing stack
453 overflows on the Mac. Hopefully fixed this by setting the recursion
454 limit much smaller. If the limit is too low (it only affects
455 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
456 when compiling cPickle.c (or in pyconfig.h).
457
Tim Peters909c0912001-12-14 23:16:18 +0000458Library
459
Barry Warsaw52acb492001-12-21 20:04:22 +0000460- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
461 close or delete time).
462
463- rfc822.py: fixed a bug where the address '<>' was converted to None
464 instead of an empty string (also fixes the email.Utils module).
465
466- xmlrpclib.py: version 1.0.0; uses precision for doubles.
467
468- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000469 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000470
Tim Peters909c0912001-12-14 23:16:18 +0000471Tools/Demos
472
473Build
474
475C API
476
477New platforms
478
479Tests
480
481Windows
482
Barry Warsaw52acb492001-12-21 20:04:22 +0000483- distutils package: fixed broken Windows installers (bdist_wininst).
484
485- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
486 instances are deleted at process exit time.
487
488- socket.py: prevent mysterious warnings when socket instances are
489 deleted at process exit time.
490
491- posixmodule.c: fix a Windows crash with stat() of a filename ending
492 in backslash.
493
Tim Peters909c0912001-12-14 23:16:18 +0000494Mac
495
Barry Warsaw52acb492001-12-21 20:04:22 +0000496- The Carbon toolbox modules have been upgraded to Universal Headers
497 3.4, and experimental CoreGraphics and CarbonEvents modules have
498 been added. All only for framework-enabled MacOSX.
499
Tim Peters909c0912001-12-14 23:16:18 +0000500
Tim Peters6272dfd2001-12-13 19:34:00 +0000501What's New in Python 2.2c1?
502Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000503===========================
504
505Type/class unification and new-style classes
506
Barry Warsaw06557452001-12-14 20:47:12 +0000507- Guido's tutorial introduction to the new type/class features has
508 been extensively updated. See
509
510 http://www.python.org/2.2/descrintro.html
511
512 That remains the primary documentation in this area.
513
Guido van Rossum33bab012001-12-05 22:45:48 +0000514- Fixed a leak: instance variables declared with __slots__ were never
515 deleted!
516
Guido van Rossum4b800852001-12-03 00:54:52 +0000517- The "delete attribute" method of descriptor objects is called
518 __delete__, not __del__. In previous releases, it was mistakenly
519 called __del__, which created an unfortunate overloading condition
520 with finalizers. (The "get attribute" and "set attribute" methods
521 are still called __get__ and __set__, respectively.)
522
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000523- Some subtle issues with the super built-in were fixed:
524
525 (a) When super itself is subclassed, its __get__ method would still
526 return an instance of the base class (i.e., of super).
527
528 (b) super(C, C()).__class__ would return C rather than super. This
529 is confusing. To fix this, I decided to change the semantics of
530 super so that it only applies to code attributes, not to data
531 attributes. After all, overriding data attributes is not
532 supported anyway.
533
534 (c) The __get__ method didn't check whether the argument was an
535 instance of the type used in creation of the super instance.
536
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000537- Previously, hash() of an instance of a subclass of a mutable type
538 (list or dictionary) would return some value, rather than raising
539 TypeError. This has been fixed. Also, directly calling
540 dict.__hash__ and list.__hash__ now raises the same TypeError
541 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000542
Guido van Rossumd331cb52001-12-05 19:46:42 +0000543- New-style objects now support deleting their __dict__. This is for
544 all intents and purposes equivalent to assigning a brand new empty
545 dictionary, but saves space if the object is not used further.
546
Tim Petersb3c9af12001-11-17 00:21:57 +0000547Core and builtins
548
Tim Peters3caca232001-12-06 06:23:26 +0000549- -Qnew now works as documented in PEP 238: when -Qnew is passed on
550 the command line, all occurrences of "/" use true division instead
551 of classic division. See the PEP for details. Note that "all"
552 means all instances in library and 3rd-party modules, as well as in
553 your own code. As the PEP says, -Qnew is intended for use only in
554 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000555 Note that test_coercion.py in the standard Python test suite fails
556 under -Qnew; this is expected, and won't be repaired until true
557 division becomes the default (in the meantime, test_coercion is
558 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000559
Fred Drake6c01e252001-12-14 17:08:12 +0000560- complex() now only allows the first argument to be a string
561 argument, and raises TypeError if either the second arg is a string
562 or if the second arg is specified when the first is a string.
563
Tim Petersb3c9af12001-11-17 00:21:57 +0000564Extension modules
565
Martin v. Löwis560da622001-11-24 09:24:51 +0000566- gc.get_referents was renamed to gc.get_referrers.
567
Tim Petersb3c9af12001-11-17 00:21:57 +0000568Library
569
Tim Peters25059d32001-12-07 20:35:43 +0000570- Functions in the os.spawn() family now release the global interpreter
571 lock around calling the platform spawn. They should always have done
572 this, but did not before 2.2c1. Multithreaded programs calling
573 an os.spawn function with P_WAIT will no longer block all Python threads
574 until the spawned program completes. It's possible that some programs
575 relies on blocking, although more likely by accident than by design.
576
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000577- webbrowser defaults to netscape.exe on OS/2 now.
578
Martin v. Löwis652e1912001-11-25 14:50:56 +0000579- Tix.ResizeHandle exposes detach_widget, hide, and show.
580
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000581- The charset alias windows_1252 has been added.
582
Barry Warsaw06557452001-12-14 20:47:12 +0000583- types.StringTypes is a tuple containing the defined string types;
584 usually this will be (str, unicode), but if Python was compiled
585 without Unicode support it will be just (str,).
586
587- The pulldom and minidom modules were synchronized to PyXML.
588
Tim Petersb3c9af12001-11-17 00:21:57 +0000589Tools/Demos
590
Barry Warsaw06557452001-12-14 20:47:12 +0000591- A new script called Tools/scripts/google.py was added, which fires
592 off a search on Google.
593
Tim Petersb3c9af12001-11-17 00:21:57 +0000594Build
595
Barry Warsaw06557452001-12-14 20:47:12 +0000596- Note that release builds of Python should arrange to define the
597 preprocessor symbol NDEBUG on the command line (or equivalent).
598 In the 2.2 pre-release series we tried to define this by magic in
599 Python.h instead, but it proved to cause problems for extension
600 authors. The Unix, Windows and Mac builds now all define NDEBUG in
601 release builds via cmdline (or equivalent) instead. Ports to
602 other platforms should do likewise.
603
Jack Jansen1999ef42001-12-06 21:47:20 +0000604- It is no longer necessary to use --with-suffix when building on a
605 case-insensitive file system (such as Mac OS X HFS+). In the build
606 directory an extension is used, but not in the installed python.
607
Tim Petersb3c9af12001-11-17 00:21:57 +0000608C API
609
Tim Petersf582b822001-12-11 18:51:08 +0000610- New function PyDict_MergeFromSeq2() exposes the builtin dict
611 constructor's logic for updating a dictionary from an iterable object
612 producing key-value pairs.
613
Tim Peterscffed4b2001-11-29 03:26:37 +0000614- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000615 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000616 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
617 dump core in some bad cases. This has been repaired. As a result,
618 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
619 previously went unchallenged.
620
Tim Petersb3c9af12001-11-17 00:21:57 +0000621New platforms
622
623Tests
624
625Windows
626
627Mac
628
Jack Jansenffa260f2001-12-06 21:14:00 +0000629- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
630 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000631
Barry Warsaw06557452001-12-14 20:47:12 +0000632- Changed logic for finding python home in Mac OS X framework Pythons.
633 Now sys.executable points to the executable again, in stead of to
634 the shared library. The latter is used only for locating the python
635 home.
636
637
Tim Peters84362bc2001-10-19 17:55:30 +0000638What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000639Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000640===========================
641
642Type/class unification and new-style classes
643
Guido van Rossum3d27df02001-11-15 20:27:54 +0000644- Multiple inheritance mixing new-style and classic classes in the
645 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000646
647 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000648 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000649
650 The MRO (method resolution order) for each base class is respected
651 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000652 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000653 This needs to be documented.
654
Tim Petersa427a2b2001-10-29 22:25:45 +0000655- The new builtin dictionary() constructor, and dictionary type, have
656 been renamed to dict. This reflects a decade of common usage.
657
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000658- dict() now accepts an iterable object producing 2-sequences. For
659 example, dict(d.items()) == d for any dictionary d. The argument,
660 and the elements of the argument, can be any iterable objects.
661
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000662- New-style classes can now have a __del__ method, which is called
663 when the instance is deleted (just like for classic classes).
664
Guido van Rossum12d955c2001-10-26 14:56:06 +0000665- Assignment to object.__dict__ is now possible, for objects that are
666 instances of new-style classes that have a __dict__ (unless the base
667 class forbids it).
668
Guido van Rossumc8e56452001-10-22 00:43:43 +0000669- Methods of built-in types now properly check for keyword arguments
670 (formerly these were silently ignored). The only built-in methods
671 that take keyword arguments are __call__, __init__ and __new__.
672
Guido van Rossum86443212001-10-27 22:28:54 +0000673- The socket function has been converted to a type; see below.
674
Tim Peters84362bc2001-10-19 17:55:30 +0000675Core and builtins
676
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000677- Assignment to __debug__ raises SyntaxError at compile-time. This
678 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000679 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000680
Guido van Rossum12d955c2001-10-26 14:56:06 +0000681- Clarified the error messages for unsupported operands to an operator
682 (like 1 + '').
683
Tim Peters84362bc2001-10-19 17:55:30 +0000684Extension modules
685
Tim Peters5ebfd362001-11-13 23:11:19 +0000686- mmap has a new keyword argument, "access", allowing a uniform way for
687 both Windows and Unix users to create read-only, write-through and
688 copy-on-write memory mappings. This was previously possible only on
689 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000690 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000691 platforms. Thanks to Jay T Miller for repairing this!
692
Tim Peters169ded02001-11-03 19:57:21 +0000693- By default, the gc.garbage list now contains only those instances in
694 unreachable cycles that have __del__ methods; in 2.1 it contained all
695 instances in unreachable cycles. "Instances" here has been generalized
696 to include instances of both new-style and old-style classes.
697
Guido van Rossum12d955c2001-10-26 14:56:06 +0000698- The socket module defines a new method for socket objects,
699 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000700 send() until all data has been sent. Also, the socket function has
701 been converted to a subclassable type, like list and tuple (etc.)
702 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000703
704- Various bugfixes to the curses module. There is now a test suite
705 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000706
Guido van Rossum692adf12001-10-30 03:03:03 +0000707- binascii.b2a_base64 no longer places an arbitrary restriction of 57
708 bytes on its input.
709
Tim Peters84362bc2001-10-19 17:55:30 +0000710Library
711
Tim Peters5ebfd362001-11-13 23:11:19 +0000712- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000713 convenience function.
714
Tim Peters75335872001-11-03 19:35:43 +0000715- Symbolic group names in regular expressions must be unique. For
716 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
717 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000718 Python 2.2 detects this error at regexp compilation time;
719 previously, the error went undetected, and results were
720 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
721 pattern.subn() methods have been rewritten in C. Also, an
722 experimental function/method finditer() has been added, which works
723 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000724
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000725- Tix exposes more commands through the classes DirSelectBox,
726 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
727 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
728 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
729
Tim Peters98791af2001-10-23 01:59:54 +0000730- Traceback objects are now scanned by cyclic garbage collection, so
731 cycles created by casual use of sys.exc_info() no longer cause
732 permanent memory leaks (provided garbage collection is enabled).
733
Guido van Rossum49192142001-10-24 20:51:44 +0000734- os.extsep -- a new variable needed by the RISCOS support. It is the
735 separator used by extensions, and is '.' on all platforms except
736 RISCOS, where it is '/'. There is no need to use this variable
737 unless you have a masochistic desire to port your code to RISCOS.
738
Barry Warsaw012852b2001-11-16 16:17:27 +0000739- mimetypes.py has optional support for non-standard, but commonly
740 found types. guess_type() and guess_extension() now accept an
741 optional `strict' flag, defaulting to true, which controls whether
742 recognize non-standard types or not. A few non-standard types we
743 know about have been added. Also, when run as a script, there are
744 new -l and -e options.
745
746- statcache is now deprecated.
747
748- email.Utils.formatdate() now produces the preferred RFC 2822 style
749 dates with numeric timezones (it used to produce obsolete dates
750 hard coded to "GMT" timezone). An optional `localtime' flag is
751 added to produce dates in the local timezone, with daylight savings
752 time properly taken into account.
753
754- In pickle and cPickle, instead of masking errors in load() by
755 transforming them into SystemError, we let the original exception
756 propagate out. Also, implement support for __safe_for_unpickling__
757 in pickle, as it already was supported in cPickle.
758
Tim Peters84362bc2001-10-19 17:55:30 +0000759Tools/Demos
760
761Build
762
Barry Warsaw012852b2001-11-16 16:17:27 +0000763- The dbm module is built using libdb1 if available. The bsddb module
764 is built with libdb3 if available.
765
766- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
767
Tim Peters84362bc2001-10-19 17:55:30 +0000768C API
769
Tim Peters1fc240e2001-10-26 05:06:50 +0000770- New function PySequence_Fast_GET_SIZE() returns the size of a non-
771 NULL result from PySequence_Fast(), more quickly than calling
772 PySequence_Size().
773
Barry Warsaw012852b2001-11-16 16:17:27 +0000774- New argument unpacking function PyArg_UnpackTuple() added.
775
776- New functions PyObject_CallFunctionObjArgs() and
777 PyObject_CallMethodObjArgs() have been added to make it more
778 convenient and efficient to call functions and methods from C.
779
780- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
781 possible that this will propagate errors it didn't before.
782
783- New function PyObject_CheckReadBuffer(), which returns true if its
784 argument supports the single-segment readable buffer interface.
785
Tim Peters84362bc2001-10-19 17:55:30 +0000786New platforms
787
Guido van Rossum86443212001-10-27 22:28:54 +0000788- We've finally confirmed that this release builds on HP-UX 11.00,
789 *with* threads, and passes the test suite.
790
Tim Peters7a33d8b2001-11-05 02:51:07 +0000791- Thanks to a series of patches from Michael Muller, Python may build
792 again under OS/2 Visual Age C++.
793
Guido van Rossum49192142001-10-24 20:51:44 +0000794- Updated RISCOS port by Dietmar Schwertberger.
795
Tim Peters84362bc2001-10-19 17:55:30 +0000796Tests
797
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000798- Added a test script for the curses module. It isn't run automatically;
799 regrtest.py must be run with '-u curses' to enable it.
800
Tim Peters84362bc2001-10-19 17:55:30 +0000801Windows
802
Barry Warsaw012852b2001-11-16 16:17:27 +0000803Mac
804
805- PythonScript has been moved to unsupported and is slated to be
806 removed completely in the next release.
807
808- It should now be possible to build applets that work on both OS9 and
809 OSX.
810
811- The core is now linked with CoreServices not Carbon; as a side
812 result, default 8bit encoding on OSX is now ASCII.
813
814- Python should now build on OSX 10.1.1
815
Tim Peters84362bc2001-10-19 17:55:30 +0000816
Tim Petersabf925f2001-09-28 21:53:42 +0000817What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000818Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000819===========================
820
821Type/class unification and new-style classes
822
Guido van Rossum687ae002001-10-15 22:03:32 +0000823- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000824 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000825 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000826 remains: the __dict__ of a new-style class is a read-only proxy; you
827 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000828 __defined__ attribute of new-style types no longer exists, for lack
829 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000830 future a __cache__ may be resurrected with a similar function, if I
831 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000832
Tim Peters1c9ca872001-10-04 06:43:12 +0000833- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
834 always returned None, even when there was a class docstring).
835
836- doctest now finds and runs docstrings attached to new-style classes,
837 class methods, static methods, and properties.
838
Guido van Rossum9074ef62001-10-16 21:34:49 +0000839Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000840
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000841- A very subtle syntactical pitfall in list comprehensions was fixed.
842 For example: [a+b for a in 'abc', for b in 'def']. The comma in
843 this example is a mistake. Previously, this would silently let 'a'
844 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
845 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
846 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
847 Note that [a for a in <singleton>] is a convoluted way to say
848 [<singleton>] anyway, so it's not like any expressiveness is lost.
849
Guido van Rossum9074ef62001-10-16 21:34:49 +0000850- getattr(obj, name, default) now only catches AttributeError, as
851 documented, rather than returning the default value for all
852 exceptions (which could mask bugs in a __getattr__ hook, for
853 example).
854
Fred Drakecb7a6b52001-10-22 18:41:51 +0000855- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000856 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000857 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000858 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000859
Guido van Rossum1c486092001-10-19 02:05:35 +0000860- unicode(obj) now behaves more like str(obj), accepting arbitrary
861 objects, and calling a __unicode__ method if it exists.
862 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000863 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000864
Barry Warsawf6fb1712001-10-19 05:35:40 +0000865- isinstance() now allows any object as the first argument and a
866 class, a type or something with a __bases__ tuple attribute for the
867 second argument. The second argument may also be a tuple of a
868 class, type, or something with __bases__, in which case isinstance()
869 will return true if the first argument is an instance of any of the
870 things contained in the second argument tuple. E.g.
871
872 isinstance(x, (A, B))
873
874 returns true if x is an instance of A or B.
875
Guido van Rossum9074ef62001-10-16 21:34:49 +0000876Extension modules
877
878- thread.start_new_thread() now returns the thread ID (previously None).
879
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000880- binascii has now two quopri support functions, a2b_qp and b2a_qp.
881
Guido van Rossumc524d952001-10-19 01:31:59 +0000882- readline now supports setting the startup_hook and the
883 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000884
Guido van Rossumc524d952001-10-19 01:31:59 +0000885- os and posix supports chroot(), setgroups() and unsetenv() where
886 available. The stat(), fstat(), statvfs() and fstatvfs() functions
887 now return "pseudo-sequences" -- the various fields can now be
888 accessed as attributes (e.g. os.stat("/").st_mtime) but for
889 backwards compatibility they also behave as a fixed-length sequence.
890 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000891 attributes.
892
893- time: localtime(), gmtime() and strptime() now return a
894 pseudo-sequence similar to the os.stat() return value, with
895 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000896
Guido van Rossum9074ef62001-10-16 21:34:49 +0000897- Decompression objects in the zlib module now accept an optional
898 second parameter to decompress() that specifies the maximum amount
899 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000900
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000901- optional SSL support in the socket module now exports OpenSSL
902 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
903 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000904 automatically seed its PRNG. Also, the keyfile and certfile
905 arguments to socket.ssl() are now optional.
906
907- posixmodule (and by extension, the os module on POSIX platforms) now
908 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000909
Guido van Rossum9074ef62001-10-16 21:34:49 +0000910Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000911
Tim Peters7402f792001-10-02 03:53:41 +0000912- doctest now excludes functions and classes not defined by the module
913 being tested, thanks to Tim Hochberg.
914
Fred Drakecb7a6b52001-10-22 18:41:51 +0000915- HotShot, a new profiler implemented using a C-based callback, has
916 been added. This substantially reduces the overhead of profiling,
917 but it is still quite preliminary. Support modules and
918 documentation will be added in upcoming releases (before 2.2 final).
919
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000920- profile now produces correct output in situations where an exception
921 raised in Python is cleared by C code (e.g. hasattr()). This used
922 to cause wrong output, including spurious claims of recursive
923 functions and attribution of time spent to the wrong function.
924
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000925 The code and documentation for the derived OldProfile and HotProfile
926 profiling classes was removed. The code hasn't worked for years (if
927 you tried to use them, they raised exceptions). OldProfile
928 intended to reproduce the behavior of the profiler Python used more
929 than 7 years ago, and isn't interesting anymore. HotProfile intended
930 to provide a faster profiler (but producing less information), and
931 that's a worthy goal we intend to meet via a different approach (but
932 without losing information).
933
Tim Peterscce092d2001-10-09 05:31:56 +0000934- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000935 a much better system-specific calibration constant. The constant can
936 now be specified in an instance constructor, or as a Profile class or
937 instance variable, instead of by editing profile.py's source code.
938 Calibration must still be done manually (see the docs for the profile
939 module).
940
941 Note that Profile.calibrate() must be overriden by subclasses.
942 Improving the accuracy required exploiting detailed knowledge of
943 profiler internals; the earlier method abstracted away the details
944 and measured a simplified model instead, but consequently computed
945 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000946
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000947- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000948 which indicates whether output is intended for the header 'Q'
949 encoding.
950
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000951- The SocketServer.ThreadingMixIn class now closes the request after
952 finish_request() returns. (Not when it errors out though.)
953
Barry Warsawf6fb1712001-10-19 05:35:40 +0000954- The nntplib module's NNTP.body() method has grown a `file' argument
955 to allow saving the message body to a file.
956
957- The email package has added a class email.Parser.HeaderParser which
958 only parses headers and does not recurse into the message's body.
959 Also, the module/class MIMEAudio has been added for representing
960 audio data (contributed by Anthony Baxter).
961
962- ftplib should be able to handle files > 2GB.
963
964- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
965 ON, and OFF.
966
Fred Drakecb7a6b52001-10-22 18:41:51 +0000967- xml.dom.minidom NodeList objects now support the length attribute
968 and item() method as required by the DOM specifications.
969
Guido van Rossumed554f62001-10-02 23:15:37 +0000970Tools/Demos
971
972- Demo/dns was removed. It no longer serves any purpose; a package
973 derived from it is now maintained by Anthony Baxter, see
974 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000975
Barry Warsawf6fb1712001-10-19 05:35:40 +0000976- The freeze tool has been made more robust, and two new options have
977 been added: -X and -E.
978
Tim Petersabf925f2001-09-28 21:53:42 +0000979Build
980
Barry Warsawf6fb1712001-10-19 05:35:40 +0000981- configure will use CXX in LINKCC if CXX is used to build main() and
982 the system requires to link a C++ main using the C++ compiler.
983
Tim Petersabf925f2001-09-28 21:53:42 +0000984C API
985
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000986- The documentation for the tp_compare slot is updated to require that
987 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
988 not correct. This is not yet enforced but will be enforced in
989 Python 2.3; even later, we may use -2 to indicate errors and +2 for
990 "NotImplemented". Right now, -1 should be used for an error return.
991
Tim Petersd38b1c72001-09-30 05:09:37 +0000992- PyLong_AsLongLong() now accepts int (as well as long) arguments.
993 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
994 as long) arguments.
995
Guido van Rossum3c288632001-10-16 21:13:49 +0000996- PyThread_start_new_thread() now returns a long int giving the thread
997 ID, if one can be calculated; it returns -1 for error, 0 if no
998 thread ID is calculated (this is an incompatible change, but only
999 the thread module used this API). This code has only really been
1000 tested on Linux and Windows; other platforms please beware (and
1001 report any bugs or strange behavior).
1002
Guido van Rossum1c486092001-10-19 02:05:35 +00001003- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1004 input.
1005
Tim Petersabf925f2001-09-28 21:53:42 +00001006New platforms
1007
1008Tests
1009
1010Windows
1011
Tim Peters04cf1d32001-10-09 22:39:40 +00001012- Installer: If you install IDLE, and don't disable file-extension
1013 registration, a new "Edit with IDLE" context (right-click) menu entry
1014 is created for .py and .pyw files.
1015
Tim Peters1ce3cf72001-10-01 17:58:40 +00001016- The signal module now supports SIGBREAK on Windows, thanks to Steven
1017 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1018 action remains to call Win32 ExitProcess(). This can be changed via
1019 signal.signal(). For example:
1020
1021 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1022 # (SIGINT) behavior.
1023 import signal
1024 signal.signal(signal.SIGBREAK,
1025 signal.default_int_handler)
1026
1027 try:
1028 while 1:
1029 pass
1030 except KeyboardInterrupt:
1031 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1032 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1033 # program without the possibility for any Python-level cleanup).
1034 print "Clean exit"
1035
Tim Petersabf925f2001-09-28 21:53:42 +00001036
Tim Petersb07352e2001-09-08 01:25:47 +00001037What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001038Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001039===========================
1040
Guido van Rossum808eea72001-09-25 04:15:41 +00001041Type/class unification and new-style classes
1042
1043- pydoc and inspect are now aware of new-style classes;
1044 e.g. help(list) at the interactive prompt now shows proper
1045 documentation for all operations on list objects.
1046
1047- Applications using Jim Fulton's ExtensionClass module can now safely
1048 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1049 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1050 examples also work again. It is hoped that Gtk and Boost also work
1051 with 2.2a4 and beyond. (If you can confirm this, please write
1052 webmaster@python.org; if there are still problems, please open a bug
1053 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001054
Tim Peters66c1a522001-09-24 21:17:50 +00001055- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001056 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001057 in the constructed property object. fget, fset and fdel weren't
1058 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1059 associate a docstring with a property.
1060
Guido van Rossum808eea72001-09-25 04:15:41 +00001061- Comparison overloading is now more completely implemented. For
1062 example, a str subclass instance can properly be compared to a str
1063 instance, and it can properly overload comparison. Ditto for most
1064 other built-in object types.
1065
1066- The repr() of new-style classes has changed; instead of <type
1067 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1068 *except* for built-in types, which are still rendered as <type
1069 'Foo'> (to avoid upsetting existing code that might parse or
1070 otherwise rely on repr() of certain type objects).
1071
1072- The repr() of new-style objects is now always <Foo object at XXX>;
1073 previously, it was sometimes <Foo instance at XXX>.
1074
1075- For new-style classes, what was previously called __getattr__ is now
1076 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001077 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001078 one in classic classes is defined which is called only if regular
1079 attribute access raises AttributeError; to catch *all* attribute
1080 access, you can use __getattribute__ (for new-style classes). If
1081 both are defined, __getattribute__ is called first, and if it raises
1082 AttributeError, __getattr__ is called.
1083
1084- The __class__ attribute of new-style objects can be assigned to.
1085 The new class must have the same C-level object layout as the old
1086 class.
1087
1088- The builtin file type can be subclassed now. In the usual pattern,
1089 "file" is the name of the builtin type, and file() is a new builtin
1090 constructor, with the same signature as the builtin open() function.
1091 file() is now the preferred way to open a file.
1092
1093- Previously, __new__ would only see sequential arguments passed to
1094 the type in a constructor call; __init__ would see both sequential
1095 and keyword arguments. This made no sense whatsoever any more, so
1096 now both __new__ and __init__ see all arguments.
1097
1098- Previously, hash() applied to an instance of a subclass of str or
1099 unicode always returned 0. This has been repaired.
1100
1101- Previously, an operation on an instance of a subclass of an
1102 immutable type (int, long, float, complex, tuple, str, unicode),
1103 where the subtype didn't override the operation (and so the
1104 operation was handled by the builtin type), could return that
1105 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001106 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001107 with the same value as s.
1108
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001109- Provisional support for pickling new-style objects has been added.
1110
Guido van Rossum808eea72001-09-25 04:15:41 +00001111Core
1112
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001113- file.writelines() now accepts any iterable object producing strings.
1114
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001115- PyUnicode_FromEncodedObject() now works very much like
1116 PyObject_Str(obj) in that it tries to use __str__/tp_str
1117 on the object if the object is not a string or buffer. This
1118 makes unicode() behave like str() when applied to non-string/buffer
1119 objects.
1120
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001121- PyFile_WriteObject now passes Unicode objects to the file's write
1122 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001123 of a print statement must support Unicode objects, i.e. they must
1124 at least convert them into ASCII strings.
1125
Guido van Rossum624c8af2001-09-18 15:21:04 +00001126- Thread scheduling on Solaris should be improved; it is no longer
1127 necessary to insert a small sleep at the start of a thread in order
1128 to let other runnable threads be scheduled.
1129
Tim Petersb07352e2001-09-08 01:25:47 +00001130Library
1131
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001132- StringIO.StringIO instances and cStringIO.StringIO instances support
1133 read character buffer compatible objects for their .write() methods.
1134 These objects are converted to strings and then handled as such
1135 by the instances.
1136
Barry Warsaw2f600732001-09-24 04:28:10 +00001137- The "email" package has been added. This is basically a port of the
1138 mimelib package <http://sf.net/projects/mimelib> with API changes
1139 and some implementations updated to use iterators and generators.
1140
Tim Peters8a9c2842001-09-22 21:30:22 +00001141- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1142 restores the ability of Tools/scripts/ndiff.py to start producing output
1143 before the entire comparison is complete.
1144
Barry Warsaw58b072d2001-09-22 04:44:21 +00001145- StringIO.StringIO instances and cStringIO.StringIO instances support
1146 iteration just like file objects (i.e. their .readline() method is
1147 called for each iteration until it returns an empty string).
1148
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001149- The codecs module has grown four new helper APIs to access
1150 builtin codecs: getencoder(), getdecoder(), getreader(),
1151 getwriter().
1152
Guido van Rossum624c8af2001-09-18 15:21:04 +00001153- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1154 simplifies writing XML RPC servers.
1155
Barry Warsaw647d5e82001-09-28 17:01:02 +00001156- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001157 after interpretation of symbolic links. On non-Unix systems, this
1158 is an alias for os.path.abspath().
1159
Tim Peters16a77ad2001-09-08 04:00:12 +00001160- operator.indexOf() (PySequence_Index() in the C API) now works with any
1161 iterable object.
1162
Guido van Rossum624c8af2001-09-18 15:21:04 +00001163- smtplib now supports various authentication and security features of
1164 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001165
Guido van Rossum624c8af2001-09-18 15:21:04 +00001166- hmac: a new module implementing keyed hashing for message
1167 authentication.
1168
1169- mimetypes now recognizes more extensions and file types. At the
1170 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001171
Guido van Rossum624c8af2001-09-18 15:21:04 +00001172- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001173 Python 2.2 bytecode generation. It has also been promoted from a
1174 Tool to a standard library package. (Tools/compiler still exists as
1175 a sample driver.)
1176
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001177Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001178
Tim Petersb07352e2001-09-08 01:25:47 +00001179Build
1180
Guido van Rossum624c8af2001-09-18 15:21:04 +00001181- Large file support (LFS) is now automatic when the platform supports
1182 it; no more manual configuration tweaks are needed. On Linux, at
1183 least, it's possible to have a system whose C library supports large
1184 files but whose kernel doesn't; in this case, large file support is
1185 still enabled but doesn't do you any good unless you upgrade your
1186 kernel or share your Python executable with another system whose
1187 kernel has large file support.
1188
1189- The configure script now supplies plausible defaults in a
1190 cross-compilation environment. This doesn't mean that the supplied
1191 values are always correct, or that cross-compilation now works
1192 flawlessly -- but it's a first step (and it shuts up most of
1193 autoconf's warnings about AC_TRY_RUN).
1194
1195- The Unix build is now a bit less chatty, courtesy of the parser
1196 generator. The build is completely silent (except for errors) when
1197 using "make -s", thanks to a -q option to setup.py.
1198
Tim Petersb07352e2001-09-08 01:25:47 +00001199C API
1200
Guido van Rossum624c8af2001-09-18 15:21:04 +00001201- The "structmember" API now supports some new flag bits to deny read
1202 and/or write access to attributes in restricted execution mode.
1203
Tim Petersb07352e2001-09-08 01:25:47 +00001204New platforms
1205
Guido van Rossum624c8af2001-09-18 15:21:04 +00001206- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1207 (http://familiar.handhelds.org).
1208
Tim Petersb07352e2001-09-08 01:25:47 +00001209Tests
1210
Tim Peters8a9c2842001-09-22 21:30:22 +00001211- The "classic" standard tests, which work by comparing stdout to
1212 an expected-output file under Lib/test/output/, no longer stop at
1213 the first mismatch. Instead the test is run to completion, and a
1214 variant of ndiff-style comparison is used to report all differences.
1215 This is much easier to understand than the previous style of reporting.
1216
1217- The unittest-based standard tests now use regrtest's test_main()
1218 convention, instead of running as a side-effect of merely being
1219 imported. This allows these tests to be run in more natural and
1220 flexible ways as unittests, outside the regrtest framework.
1221
1222- regrtest.py is much better integrated with unittest and doctest now,
1223 especially in regard to reporting errors.
1224
Tim Petersb07352e2001-09-08 01:25:47 +00001225Windows
1226
Guido van Rossum624c8af2001-09-18 15:21:04 +00001227- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001228 that support it (NTFS under Windows 2000). See "What's New in
1229 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001230
Tim Petersb07352e2001-09-08 01:25:47 +00001231
Tim Petersedc99312001-08-22 21:36:50 +00001232What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001233Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001234===========================
1235
1236Core
1237
Tim Peters9fffa3e2001-09-04 05:14:19 +00001238- Conversion of long to float now raises OverflowError if the long is too
1239 big to represent as a C double.
1240
Tim Peters32f453e2001-09-03 08:35:41 +00001241- The 3-argument builtin pow() no longer allows a third non-None argument
1242 if either of the first two arguments is a float, or if both are of
1243 integer types and the second argument is negative (in which latter case
1244 the arguments are converted to float, so this is really the same
1245 restriction).
1246
Tim Peters5d2b77c2001-09-03 05:47:38 +00001247- The builtin dir() now returns more information, and sometimes much
1248 more, generally naming all attributes of an object, and all attributes
1249 reachable from the object via its class, and from its class's base
1250 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1251 an empty list. In 2.2a3,
1252
1253 >>> dir([])
1254 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1255 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1256 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1257 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1258 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1259 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1260 'reverse', 'sort']
1261
1262 dir(module) continues to return only the module's attributes, though.
1263
Tim Petersbdee63f2001-09-02 03:40:59 +00001264- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001265 than raising OverflowError. This is a partial implementation of PEP
1266 237. You can use -Wdefault::OverflowWarning to enable a warning for
1267 this situation, and -Werror::OverflowWarning to revert to the old
1268 OverflowError exception.
1269
Guido van Rossum61c345f2001-09-04 03:26:15 +00001270- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001271 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001272 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1273 -Qold, meaning the / operator has its classic meaning and no
1274 warnings are issued. Using -Qwarn issues a run-time warning about
1275 all uses of classic division for int and long arguments; -Qwarnall
1276 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001277 (for use with fixdiv.py).
1278 [Note: the remainder of this paragraph (preserved below) became
1279 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1280 <obsolete>
1281 Using -Qnew is questionable; it turns on new division by default, but
1282 only in the __main__ module. You can usefully combine -Qwarn or
1283 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1284 warns about classic division everywhere else.
1285 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001286
Tim Petersbdee63f2001-09-02 03:40:59 +00001287- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001288 long, float, str, unicode, and tuple. (The types complex, list and
1289 dictionary can also be subclassed; this was introduced earlier.)
1290 Note that restrictions apply when subclassing immutable built-in
1291 types: you can only affect the value of the instance by overloading
1292 __new__. You can add mutable attributes, and the subclass instances
1293 will have a __dict__ attribute, but you cannot change the "value"
1294 (as implemented by the base class) of an immutable subclass instance
1295 once it is created.
1296
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001297- The dictionary constructor now takes an optional argument, a
1298 mapping-like object, and initializes the dictionary from its
1299 (key, value) pairs.
1300
Tim Petersbdee63f2001-09-02 03:40:59 +00001301- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001302 "cooperative super calls" in a multiple inheritance setting. For an
1303 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1304
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001305- A new built-in type, property, has been added. This enables the
1306 creation of "properties". These are attributes implemented by
1307 getter and setter functions (or only one of these for read-only or
1308 write-only attributes), without the need to override __getattr__.
1309 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001310
Tim Petersbdee63f2001-09-02 03:40:59 +00001311- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001312 liberalized, to allow leading zeroes. Examples of literals now
1313 legal that were SyntaxErrors before:
1314
1315 00.0 0e3 0100j 07.5 00000000000000000008.
1316
Tim Petersbdee63f2001-09-02 03:40:59 +00001317- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001318 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1319
Tim Petersedc99312001-08-22 21:36:50 +00001320Library
1321
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001322- telnetlib includes symbolic names for the options, and support for
1323 setting an option negotiation callback.
1324
Tim Petersa40c7932001-09-05 22:36:56 +00001325- The new C standard no longer requires that math libraries set errno to
1326 ERANGE on overflow. For platform libraries that exploit this new
1327 freedom, Python's overflow-checking was wholly broken. A new overflow-
1328 checking scheme attempts to repair that, but may not be reliable on all
1329 platforms (C doesn't seem to provide anything both useful and portable
1330 in this area anymore).
1331
Martin v. Löwis44f86962001-09-05 13:44:54 +00001332- Asynchronous timeout actions are available through the new class
1333 threading.Timer.
1334
Tim Peters78526162001-09-05 00:53:45 +00001335- math.log and math.log10 now return sensible results for even huge
1336 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1337
Tim Petersbdee63f2001-09-02 03:40:59 +00001338- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001339 currently held. See the docs for the imp module.
1340
Tim Petersbdee63f2001-09-02 03:40:59 +00001341- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001342 dumps containing ints written on platforms where Python ints are 8 bytes.
1343 When read on a box where Python ints are 4 bytes, such values are
1344 converted to Python longs.
1345
Tim Petersbdee63f2001-09-02 03:40:59 +00001346- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001347 code objects is no longer allowed. This plugs a security hole.
1348
Steve Purcell6091cd62001-09-06 16:05:17 +00001349- unittest.TestResult instances no longer store references to tracebacks
1350 generated by test failures. This prevents unexpected dangling references
1351 to objects that should be garbage collected between tests.
1352
Tim Petersedc99312001-08-22 21:36:50 +00001353Tools
1354
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001355- Tools/scripts/fixdiv.py has been added which can be used to fix
1356 division operators as per PEP 238.
1357
Tim Petersedc99312001-08-22 21:36:50 +00001358Build
1359
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001360- If you are an adventurous person using Mac OS X you may want to look at
1361 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1362 application, which can be used for experimenting with Carbon or Cocoa.
1363 Discussion of this on pythonmac-sig, please.
1364
Tim Peters7eea37e2001-09-04 22:08:56 +00001365C API
1366
1367- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001368
Tim Peters9fffa3e2001-09-04 05:14:19 +00001369- Note that PyLong_AsDouble can fail! This has always been true, but no
1370 callers checked for it. It's more likely to fail now, because overflow
1371 errors are properly detected now. The proper way to check:
1372
1373 double x = PyLong_AsDouble(some_long_object);
1374 if (x == -1.0 && PyErr_Occurred()) {
1375 /* The conversion failed. */
1376 }
1377
Tim Petersbdee63f2001-09-02 03:40:59 +00001378- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001379 compile but will not participate in GC. To upgrade an extension
1380 module:
1381
1382 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001383
Neil Schemenauer4042c692001-08-30 15:38:01 +00001384 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1385 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001386
Neil Schemenauer4042c692001-08-30 15:38:01 +00001387 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1388 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001389
Neil Schemenauer4042c692001-08-30 15:38:01 +00001390 - remove PyGC_HEAD_SIZE from object size calculations
1391
1392 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1393
Tim Petersbdee63f2001-09-02 03:40:59 +00001394- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001395 These can be used safely to construct string objects from a
1396 sprintf-style format string (similar to the format string supported
1397 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001398
Tim Petersedc99312001-08-22 21:36:50 +00001399New platforms
1400
Tim Petersb7da0902001-09-02 23:01:43 +00001401- Stephen Hansen contributed patches sufficient to get a clean compile
1402 under Borland C (Windows), but he reports problems running it and ran
1403 out of time to complete the port. Volunteers? Expect a MemoryError
1404 when importing the types module; this is probably shallow, and
1405 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001406
Tim Petersedc99312001-08-22 21:36:50 +00001407Tests
1408
1409Windows
1410
Tim Peters6e13a562001-09-06 00:32:15 +00001411- Large file support is now enabled on Win32 platforms as well as on
1412 Win64. This means that, for example, you can use f.tell() and f.seek()
1413 to manipulate files larger than 2 gigabytes (provided you have enough
1414 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001415 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1416 filesize limit, and large file support makes no difference there.
1417 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1418 NTFS has no practical limit on file size, and files of any size can be
1419 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001420
Tim Petersbdee63f2001-09-02 03:40:59 +00001421- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001422 points to command.com (patch from Brian Quinlan).
1423
Tim Petersedc99312001-08-22 21:36:50 +00001424
Tim Peters20f51a72001-07-21 02:31:40 +00001425What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001426Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001427===========================
1428
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001429Build
1430
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001431- Tim Peters developed a brand new Windows installer using Wise 8.1,
1432 generously donated to us by Wise Solutions.
1433
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001434- configure supports a new option --enable-unicode, with the values
1435 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1436 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001437
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001438- A new configure option --enable-framework builds a Mac OS X framework,
1439 which "make frameworkinstall" will install. This provides a starting
1440 point for more mac-like functionality, join pythonmac-sig@python.org
1441 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001442
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001443- The NeXT platform is no longer supported.
1444
1445- The `new' module is now statically linked.
1446
Tim Peters0afb6092001-08-15 06:06:44 +00001447Tools
1448
1449- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001450 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001451 the module docstring for details.
1452
Tim Peters20f51a72001-07-21 02:31:40 +00001453Tests
1454
Tim Peters5e824c32001-08-12 22:25:01 +00001455- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001456 platforms, allowing to give clearer test result output. regrtest
1457 also has optional --use/-u switch to run normally disabled tests
1458 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001459
Tim Peters20f51a72001-07-21 02:31:40 +00001460- Several new tests in the standard test suite, with special thanks to
1461 Nick Mathewson.
1462
1463Core
1464
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001465- The floor division operator // has been added as outlined in PEP
1466 238. The / operator still provides classic division (and will until
1467 Python 3.0) unless "from __future__ import division" is included, in
1468 which case the / operator will provide true division. The operator
1469 module provides truediv() and floordiv() functions. Augmented
1470 assignment variants are included, as are the equivalent overloadable
1471 methods and C API methods. See the PEP for a full discussion:
1472 <http://python.sf.net/peps/pep-0238.html>
1473
Tim Peters6cd6a822001-08-17 22:11:27 +00001474- Future statements are now effective in simulated interactive shells
1475 (like IDLE). This should "just work" by magic, but read Michael
1476 Hudson's "Future statements in simulated shells" PEP 264 for full
1477 details: <http://python.sf.net/peps/pep-0264.html>.
1478
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001479- The type/class unification (PEP 252-253) was integrated into the
1480 trunk and is not so tentative any more (the exact specification of
1481 some features is still tentative). A lot of work has done on fixing
1482 bugs and adding robustness and features (performance still has to
1483 come a long way).
1484
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001485- Warnings about a mismatch in the Python API during extension import
1486 now use the Python warning framework (which makes it possible to
1487 write filters for these warnings).
1488
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001489- A function's __dict__ (aka func_dict) will now always be a
1490 dictionary. It used to be possible to delete it or set it to None,
1491 but now both actions raise TypeErrors. It is still legal to set it
1492 to a dictionary object. Getting func.__dict__ before any attributes
1493 have been assigned now returns an empty dictionary instead of None.
1494
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001495- A new command line option, -E, was added which disables the use of
1496 all environment variables, or at least those that are specifically
1497 significant to Python. Usually those have a name starting with
1498 "PYTHON". This was used to fix a problem where the tests fail if
1499 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1500 older distribution.
1501
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001502Library
1503
Tim Peters5e824c32001-08-12 22:25:01 +00001504- New class Differ and new functions ndiff() and restore() in difflib.py.
1505 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001506 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001507
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001508- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1509 value using the minimal quoting required for the value; more
1510 reliable than using xml.sax.saxutils.escape() for attribute values.
1511
1512- Readline completion support for cmd.Cmd was added.
1513
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001514- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1515
1516- Added function threading.BoundedSemaphore()
1517
1518- Added Ka-Ping Yee's cgitb.py module.
1519
1520- The `new' module now exposes the CO_xxx flags.
1521
Martin v. Löwis560da622001-11-24 09:24:51 +00001522- The gc module offers the get_referents function.
1523
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001524New platforms
1525
1526C API
1527
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001528- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1529 which provide a cross-platform implementations for the
1530 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1531 the standard sprintf() and vsprintf() C lib APIs, these versions
1532 apply bounds checking on the used buffer which enhances protection
1533 against buffer overruns.
1534
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001535- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001536 and extensions using different Unicode widths is rendered next to
1537 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001538 will result in an ImportError. Unicode extensions writers must make
1539 sure to check the Unicode width compatibility in their extensions by
1540 using at least one of the mangled Unicode APIs in the extension.
1541
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001542- Two new flags METH_NOARGS and METH_O are available in method definition
1543 tables to simplify implementation of methods with no arguments and a
1544 single untyped argument. Calling such methods is more efficient than
1545 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1546 deprecated.
1547
Tim Petersc1731372001-08-04 08:12:36 +00001548Windows
1549
1550- "import module" now compiles module.pyw if it exists and nothing else
1551 relevant is found.
1552
Tim Peters20f51a72001-07-21 02:31:40 +00001553
Guido van Rossum55a78992001-07-17 17:22:32 +00001554What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001555Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001556===========================
1557
1558Core
Tim Petersa814db52001-05-14 07:05:58 +00001559
Tim Peters6d6c1a32001-08-02 04:15:00 +00001560- TENTATIVELY, a large amount of code implementing much of what's
1561 described in PEP 252 (Making Types Look More Like Classes) and PEP
1562 253 (Subtyping Built-in Types) was added. This will be released
1563 with Python 2.2a1. Documentation will be provided separately
1564 through http://www.python.org/2.2/. The purpose of releasing this
1565 with Python 2.2a1 is to test backwards compatibility. It is
1566 possible, though not likely, that a decision is made not to release
1567 this code as part of 2.2 final, if any serious backwards
1568 incompapatibilities are found during alpha testing that cannot be
1569 repaired.
1570
Guido van Rossum55a78992001-07-17 17:22:32 +00001571- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001572 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001573 more 'yield' statements. See PEP 255. Since this adds a new
1574 keyword to the language, this feature must be enabled by including a
1575 future statement: "from __future__ import generators" (see PEP 236).
1576 Generators will become a standard feature in a future release
1577 (probably 2.3). Without this future statement, 'yield' remains an
1578 ordinary identifier, but a warning is issued each time it is used.
1579 (These warnings currently don't conform to the warnings framework of
1580 PEP 230; we intend to fix this in 2.2a2.)
1581
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001582- The UTF-16 codec was modified to be more RFC compliant. It will now
1583 only remove BOM characters at the start of the string and then
1584 only if running in native mode (UTF-16-LE and -BE won't remove a
1585 leading BMO character).
1586
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001587- Strings now have a new method .decode() to complement the already
1588 existing .encode() method. These two methods provide direct access
1589 to the corresponding decoders and encoders of the registered codecs.
1590
1591 To enhance the usability of the .encode() method, the special
1592 casing of Unicode object return values was dropped (Unicode objects
1593 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001594
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001595 Both methods will now return whatever the codec in charge of the
1596 requested encoding returns as object, e.g. Unicode codecs will
1597 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1598 will return u"äöü"). This enables codec writer to create codecs
1599 for various simple to use conversions.
1600
1601 New codecs were added to demonstrate these new features (the .encode()
1602 and .decode() columns indicate the type of the returned objects):
1603
1604 Name | .encode() | .decode() | Description
1605 ----------------------------------------------------------------------
1606 uu | string | string | UU codec (e.g. for email)
1607 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001608 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001609 zlib | string | string | zlib compression
1610 hex | string | string | 2-byte hex codec
1611 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1612
Mark Hammond2a0af792001-05-14 03:09:36 +00001613- Some operating systems now support the concept of a default Unicode
1614 encoding for file system operations. Notably, Windows supports 'mbcs'
1615 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001616 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001617 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001618
1619 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001620 functions that return filenames (such as os.listdir()) to return Python
1621 string objects pre-encoded using the default file system encoding for
1622 the platform. As this encoding is likely to be different from Python's
1623 default encoding, converting this name to a Unicode object before passing
1624 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001625 would attempt to use its default encoding (generally ASCII) rather than
1626 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001627
Tim Petersa814db52001-05-14 07:05:58 +00001628 In general, this change simply removes surprises when working with
1629 Unicode and the file system, making these operations work as you expect,
1630 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001631 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001632
Tim Peters61dff2b2001-05-08 15:43:37 +00001633- Float (and complex) literals in source code were evaluated to full
1634 precision only when running from a .py file; the same code loaded from a
1635 .pyc (or .pyo) file could suffer numeric differences starting at about the
1636 12th significant decimal digit. For example, on a machine with IEEE-754
1637 floating arithmetic,
1638
1639 x = 9007199254740992.0
1640 print long(x)
1641
1642 printed 9007199254740992 if run directly from .py, but 9007199254740000
1643 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1644 str(float) instead of repr(float) when building code objects. marshal
1645 now uses repr(float) instead, which should reproduce floats to full
1646 machine precision (assuming the platform C float<->string I/O conversion
1647 functions are of good quality).
1648
1649 This may cause floating-point results to change in some cases, and
1650 usually for the better, but may also cause numerically unstable
1651 algorithms to break.
1652
Tim Peters2f228e72001-05-13 00:19:31 +00001653- The implementation of dicts suffers fewer collisions, which has speed
1654 benefits. However, the order in which dict entries appear in dict.keys(),
1655 dict.values() and dict.items() may differ from previous releases for a
1656 given dict. Nothing is defined about this order, so no program should
1657 rely on it. Nevertheless, it's easy to write test cases that rely on the
1658 order by accident, typically because of printing the str() or repr() of a
1659 dict to an "expected results" file. See Lib/test/test_support.py's new
1660 sortdict(dict) function for a simple way to display a dict in sorted
1661 order.
1662
Tim Peters7a3bfc32001-06-12 01:22:22 +00001663- Many other small changes to dicts were made, resulting in faster
1664 operation along the most common code paths.
1665
Guido van Rossum10315822001-05-01 20:54:30 +00001666- Dictionary objects now support the "in" operator: "x in dict" means
1667 the same as dict.has_key(x).
1668
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001669- The update() method of dictionaries now accepts generic mapping
1670 objects. Specifically the argument object must support the .keys()
1671 and __getitem__() methods. This allows you to say, for example,
1672 {}.update(UserDict())
1673
Guido van Rossum10315822001-05-01 20:54:30 +00001674- Iterators were added; this is a generalized way of providing values
1675 to a for loop. See PEP 234. There's a new built-in function iter()
1676 to return an iterator. There's a new protocol to get the next value
1677 from an iterator using the next() method (in Python) or the
1678 tp_iternext slot (in C). There's a new protocol to get iterators
1679 using the __iter__() method (in Python) or the tp_iter slot (in C).
1680 Iterating (i.e. a for loop) over a dictionary generates its keys.
1681 Iterating over a file generates its lines.
1682
Tim Petersf553f892001-05-01 20:45:31 +00001683- The following functions were generalized to work nicely with iterator
1684 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001685 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001686 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1687 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001688 join() method of strings
1689 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001690 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1691 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001692 right-hand side of assignment statements with multiple targets, such as
1693 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001694
Tim Petersd85e1022001-05-11 21:51:48 +00001695- Accessing module attributes is significantly faster (for example,
1696 random.random or os.path or yourPythonModule.yourAttribute).
1697
Tim Peterse63415e2001-05-08 04:38:29 +00001698- Comparing dictionary objects via == and != is faster, and now works even
1699 if the keys and values don't support comparisons other than ==.
1700
Tim Peters95bf9392001-05-10 08:32:44 +00001701- Comparing dictionaries in ways other than == and != is slower: there were
1702 insecurities in the dict comparison implementation that could cause Python
1703 to crash if the element comparison routines for the dict keys and/or
1704 values mutated the dicts. Making the code bulletproof slowed it down.
1705
Tim Peterseb28ef22001-06-02 05:27:19 +00001706- Collisions in dicts are resolved via a new approach, which can help
1707 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001708 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001709 faster now. Thanks to Christian Tismer for pointing out the cause and
1710 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001711
Tim Peters52e155e2001-06-16 05:42:57 +00001712- repr() is much faster for large containers (dict, list, tuple).
1713
1714
Tim Petersa814db52001-05-14 07:05:58 +00001715Library
1716
Fred Drake960fdf92001-07-20 18:38:26 +00001717- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1718 were added to the string module. These a locale-indenpendent
1719 constants, unlike letters, lowercase, and uppercase. These are now
1720 use in appropriate locations in the standard library.
1721
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001722- The flags used in dlopen calls can now be configured using
1723 sys.setdlopenflags and queried using sys.getdlopenflags.
1724
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001725- Fredrik Lundh's xmlrpclib is now a standard library module. This
1726 provides full client-side XML-RPC support. In addition,
1727 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1728 one asyncore-based). Thanks to Eric Raymond for the documentation.
1729
Guido van Rossum643d3912001-07-05 14:46:25 +00001730- The xrange() object is simplified: it no longer supports slicing,
1731 repetition, comparisons, efficient 'in' checking, the tolist()
1732 method, or the start, stop and step attributes. See PEP 260.
1733
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001734- A new function fnmatch.filter to filter lists of file names was added.
1735
Barry Warsawffd674d2001-05-22 16:00:10 +00001736- calendar.py uses month and day names based on the current locale.
1737
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001738- strop is now *really* obsolete (this was announced before with 1.6),
1739 and issues DeprecationWarning when used (except for the four items
1740 that are still imported into string.py).
1741
Tim Petersa814db52001-05-14 07:05:58 +00001742- Cookie.py now sorts key+value pairs by key in output strings.
1743
1744- pprint.isrecursive(object) didn't correctly identify recursive objects.
1745 Now it does.
1746
Tim Peters95b3f782001-05-14 18:39:41 +00001747- pprint functions now much faster for large containers (tuple, list, dict).
1748
Tim Peters7b9542a2001-06-10 23:40:19 +00001749- New 'q' and 'Q' format codes in the struct module, corresponding to C
1750 types "long long" and "unsigned long long" (on Windows, __int64). In
1751 native mode, these can be used only when the platform C compiler supports
1752 these types (when HAVE_LONG_LONG is #define'd by the Python config
1753 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001754 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1755 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001756
Guido van Rossum83213cc2001-06-12 16:48:52 +00001757- The site module installs a new built-in function 'help' that invokes
1758 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1759 it displays a message reminding the user to use 'help()' or
1760 'help(object)'.
1761
Tim Petersa814db52001-05-14 07:05:58 +00001762Tests
1763
1764- New test_mutants.py runs dict comparisons where the key and value
1765 comparison operators mutute the dicts randomly during comparison. This
1766 rapidly causes Python to crash under earlier releases (not for the faint
1767 of heart: it can also cause Win9x to freeze or reboot!).
1768
1769- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001770 pprint.isreadable() return sensible results. Also verifies that simple
1771 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001772
Tim Peters4324aa32001-05-28 22:30:08 +00001773C API
1774
1775- Removed the unused last_is_sticky argument from the internal
1776 _PyTuple_Resize(). If this affects you, you were cheating.
1777
1778
Guido van Rossum55a78992001-07-17 17:22:32 +00001779======================================================================
1780
1781
Guido van Rossumffe13be2001-04-16 18:46:45 +00001782What's New in Python 2.1 (final)?
1783=================================
1784
1785We only changed a few things since the last release candidate, all in
1786Python library code:
1787
1788- A bug in the locale module was fixed that affected locales which
1789 define no grouping for numeric formatting.
1790
1791- A few bugs in the weakref module's implementations of weak
1792 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1793 and the test suite was updated to check for these bugs.
1794
1795- An old bug in the os.path.walk() function (introduced in Python
1796 2.0!) was fixed: a non-existent file would cause an exception
1797 instead of being ignored.
1798
1799- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1800 PyChecker.
1801
1802
Guido van Rossum5b08f132001-04-16 02:05:23 +00001803What's New in Python 2.1c2?
1804===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001805
Guido van Rossum5b08f132001-04-16 02:05:23 +00001806A flurry of small changes, and one showstopper fixed in the nick of
1807time made it necessary to release another release candidate. The list
1808here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001809
Guido van Rossum5b08f132001-04-16 02:05:23 +00001810Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001811
Guido van Rossum5b08f132001-04-16 02:05:23 +00001812- Tim discovered a nasty bug in the dictionary code, caused by
1813 PyDict_Next() calling dict_resize(), and the GC code's use of
1814 PyDict_Next() violating an assumption in dict_items(). This was
1815 fixed with considerable amounts of band-aid, but the net effect is a
1816 saner and more robust implementation.
1817
1818- Made a bunch of symbols static that were accidentally global.
1819
1820Build and Ports
1821
1822- The setup.py script didn't check for a new enough version of zlib
1823 (1.1.3 is needed). Now it does.
1824
1825- Changed "make clean" target to also remove shared libraries.
1826
1827- Added a more general warning about the SGI Irix optimizer to README.
1828
1829Library
1830
1831- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1832 omitted the slash between host and file.html.
1833
1834- The mailbox module's _Mailbox class contained a completely broken
1835 and undocumented seek() method. Ripped it out.
1836
1837- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1838 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1839
1840- Fixed a few last-minute bugs in unittest.
1841
1842Extensions
1843
1844- Reverted the patch to the OpenSSL code in socketmodule.c to support
1845 RAND_status() and the EGD, and the subsequent patch that tried to
1846 fix it for pre-0.9.5 versions; the problem with the patch is that on
1847 some systems it issues a warning whenever socket is imported, and
1848 that's unacceptable.
1849
1850Tests
1851
1852- Fixed the pickle tests to work with "import test.test_pickle".
1853
1854- Tweaked test_locale.py to actually run the test Windows.
1855
1856- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1857 not "wb" (which is not a valid mode at all).
1858
1859- Fix pstats browser crashes. Import readline if it exists to make
1860 the user interface nicer.
1861
1862- Add "import thread" to the top of test modules that import the
1863 threading module (test_asynchat and test_threadedtempfile). This
1864 prevents test failures caused by a broken threading module resulting
1865 from a previously caught failed import.
1866
1867- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1868 needed on some platforms (e.g. Solaris 8) when the tests are run
1869 twice in succession.
1870
1871- Skip rather than fail test_sunaudiodev if no audio device is found.
1872
1873
1874What's New in Python 2.1c1?
1875===========================
1876
1877This list was significantly updated when 2.1c2 was released; the 2.1c1
1878release didn't mention most changes that were actually part of 2.1c1:
1879
1880Legal
1881
1882- Copyright was assigned to the Python Software Foundation (PSF) and a
1883 PSF license (very similar to the CNRI license) was added.
1884
1885- The CNRI copyright notice was updated to include 2001.
1886
1887Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001888
Guido van Rossumc9932722001-04-12 02:31:27 +00001889- After a public outcry, assignment to __debug__ is no longer illegal;
1890 instead, a warning is issued. It will become illegal in 2.2.
1891
Guido van Rossum5b08f132001-04-16 02:05:23 +00001892- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1893 "%#x" now always prepends "0x", even if the value is zero.
1894
1895- Fixed some nits in the bytecode compiler.
1896
1897- Fixed core dumps when calling certain kinds of non-functions.
1898
1899- Fixed various core dumps caused by reference count bugs.
1900
1901Build and Ports
1902
1903- Use INSTALL_SCRIPT to install script files.
1904
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001905- New port: SCO Unixware 7, by Billy G. Allie.
1906
Guido van Rossum5b08f132001-04-16 02:05:23 +00001907- Updated RISCOS port.
1908
1909- Updated BeOS port and notes.
1910
1911- Various other porting problems resolved.
1912
1913Library
1914
1915- The TERMIOS and SOCKET modules are now truly obsolete and
1916 unnecessary. Their symbols are incorporated in the termios and
1917 socket modules.
1918
1919- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1920 better tests for pickling.
1921
1922- threading: make Condition.wait() robust against KeyboardInterrupt.
1923
1924- zipfile: add support to zipfile to support opening an archive
1925 represented by an open file rather than a file name. Fix bug where
1926 the archive was not properly closed. Fixed a bug in this bugfix
1927 where flush() was called for a read-only file.
1928
1929- imputil: added an uninstall() method to the ImportManager.
1930
1931- Canvas: fixed bugs in lower() and tkraise() methods.
1932
1933- SocketServer: API change (added overridable close_request() method)
1934 so that the TCP server can explicitly close the request.
1935
1936- pstats: Eric Raymond added a simple interactive statistics browser,
1937 invoked when the module is run as a script.
1938
1939- locale: fixed a problem in format().
1940
1941- webbrowser: made it work when the BROWSER environment variable has a
1942 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1943 KDE 2. Fixed some other nits.
1944
1945- unittest: changes to allow using a different exception than
1946 AssertionError, and added a few more function aliases. Some other
1947 small changes.
1948
1949- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1950
1951- asynchat: fixed a critical bug in asynchat that slipped through the
1952 2.1b2 release. Fixed another rare bug.
1953
1954- Fix some unqualified except: clauses (always a bad code example).
1955
1956XML
1957
1958- pyexpat: new API get_version_string().
1959
1960- Fixed some minidom bugs.
1961
1962Extensions
1963
1964- Fixed a core dump in _weakref. Removed the weakref.mapping()
1965 function (it adds nothing to the API).
1966
1967- Rationalized the use of header files in the readline module, to make
1968 it compile (albeit with some warnings) with the very recent readline
1969 4.2, without breaking for earlier versions.
1970
1971- Hopefully fixed a buffering problem in linuxaudiodev.
1972
1973- Attempted a fix to make the OpenSSL support in the socket module
1974 work again with pre-0.9.5 versions of OpenSSL.
1975
1976Tests
1977
1978- Added a test case for asynchat and asyncore.
1979
1980- Removed coupling between tests where one test failing could break
1981 another.
1982
1983Tools
1984
1985- Ping added an interactive help browser to pydoc, fixed some nits
1986 in the rest of the pydoc code, and added some features to his
1987 inspect module.
1988
1989- An updated python-mode.el version 4.1 which integrates Ken
1990 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1991 much nicer in XEmacs and Emacs. When stepping through your program
1992 with pdb, in either the shell window or the *Python* window, the
1993 source file and line will be tracked by an arrow. Very cool!
1994
1995- IDLE: syntax warnings in interactive mode are changed into errors.
1996
1997- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001998 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001999
2000- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002001
Barry Warsaw11e89c72001-04-11 20:37:57 +00002002
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002003What's New in Python 2.1 beta 2?
2004================================
2005
Guido van Rossum053ae352001-03-22 14:17:21 +00002006(Unlisted are many fixed bugs, more documentation, etc.)
2007
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002008Core language, builtins, and interpreter
2009
Guido van Rossum053ae352001-03-22 14:17:21 +00002010- The nested scopes work (enabled by "from __future__ import
2011 nested_scopes") is completed; in particular, the future now extends
2012 into code executed through exec, eval() and execfile(), and into the
2013 interactive interpreter.
2014
2015- When calling a base class method (e.g. BaseClass.__init__(self)),
2016 this is now allowed even if self is not strictly spoken a class
2017 instance (e.g. when using metaclasses or the Don Beaudry hook).
2018
2019- Slice objects are now comparable but not hashable; this prevents
2020 dict[:] from being accepted but meaningless.
2021
2022- Complex division is now calculated using less braindead algorithms.
2023 This doesn't change semantics except it's more likely to give useful
2024 results in extreme cases. Complex repr() now uses full precision
2025 like float repr().
2026
2027- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2028
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002029- It is illegal to assign to the name __debug__, which is set when the
2030 interpreter starts. It is effectively a compile-time constant.
2031
2032- A warning will be issued if a global statement for a variable
2033 follows a use or assignment of that variable.
2034
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002035Standard library
2036
Guido van Rossum053ae352001-03-22 14:17:21 +00002037- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2038 inspired by JUnit), is now part of the standard library. You now
2039 have a choice of two testing frameworks: unittest requires you to
2040 write testcases as separate code, doctest gathers them from
2041 docstrings. Both approaches have their advantages and
2042 disadvantages.
2043
2044- A new module Tix was added, which wraps the Tix extension library
2045 for Tk. With that module, it is not necessary to statically link
2046 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2047 require" command. See Demo/tix/.
2048
2049- tzparse.py is now obsolete.
2050
2051- In gzip.py, the seek() and tell() methods are removed -- they were
2052 non-functional anyway, and it's better if callers can test for their
2053 existence with hasattr().
2054
2055Python/C API
2056
2057- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2058 that's already in the dictionary during a PyDict_Next() iteration.
2059 This used to fail occasionally when a dictionary resize operation
2060 could be triggered that would rehash all the keys. All other
2061 modifications to the dictionary are still off-limits during a
2062 PyDict_Next() iteration!
2063
2064- New extended APIs related to passing compiler variables around.
2065
2066- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2067 implement isinstance() and issubclass().
2068
2069- Py_BuildValue() now has a "D" conversion to create a Python complex
2070 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002071
Fred Drake4e262a92001-03-22 18:26:47 +00002072- Extensions types which support weak references must now set the
2073 field allocated for the weak reference machinery to NULL themselves;
2074 this is done to avoid the cost of checking each object for having a
2075 weakly referencable type in PyObject_INIT(), since most types are
2076 not weakly referencable.
2077
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002078- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2079 free variables and cell variables to and from the frame's f_locals.
2080
2081- Variants of several functions defined in pythonrun.h have been added
2082 to support the nested_scopes future statement. The variants all end
2083 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2084 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2085 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002086 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002087
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002088Distutils
2089
2090- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2091 into the release tree.
2092
Tim Peters0e57abf2001-05-02 07:39:38 +00002093- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002094 (an uninstaller, more customization of the installer's display)
2095
2096- from Jack Jansen: added Mac-specific code to generate a dialog for
2097 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002098 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002099 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002100
2101- added 'platforms' and 'keywords' to the set of metadata that can be
2102 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002103
2104- applied patches from Jason Tishler to make the compiler class work with
2105 Cygwin.
2106
2107
Tim Peters2fe289a2001-03-01 22:19:38 +00002108What's New in Python 2.1 beta 1?
2109================================
Tim Petersd66595f2001-02-04 03:09:53 +00002110
2111Core language, builtins, and interpreter
2112
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002113- Following an outcry from the community about the amount of code
2114 broken by the nested scopes feature introduced in 2.1a2, we decided
2115 to make this feature optional, and to wait until Python 2.2 (or at
2116 least 6 months) to make it standard. The option can be enabled on a
2117 per-module basis by adding "from __future__ import nested_scopes" at
2118 the beginning of a module (before any other statements, but after
2119 comments and an optional docstring). See PEP 236 (Back to the
2120 __future__) for a description of the __future__ statement. PEP 227
2121 (Statically Nested Scopes) has been updated to reflect this change,
2122 and to clarify the semantics in a number of endcases.
2123
2124- The nested scopes code, when enabled, has been hardened, and most
2125 bugs and memory leaks in it have been fixed.
2126
2127- Compile-time warnings are now generated for a number of conditions
2128 that will break or change in meaning when nested scopes are enabled:
2129
2130 - Using "from...import *" or "exec" without in-clause in a function
2131 scope that also defines a lambda or nested function with one or
2132 more free (non-local) variables. The presence of the import* or
2133 bare exec makes it impossible for the compiler to determine the
2134 exact set of local variables in the outer scope, which makes it
2135 impossible to determine the bindings for free variables in the
2136 inner scope. To avoid the warning about import *, change it into
2137 an import of explicitly name object, or move the import* statement
2138 to the global scope; to avoid the warning about bare exec, use
2139 exec...in... (a good idea anyway -- there's a possibility that
2140 bare exec will be deprecated in the future).
2141
2142 - Use of a global variable in a nested scope with the same name as a
2143 local variable in a surrounding scope. This will change in
2144 meaning with nested scopes: the name in the inner scope will
2145 reference the variable in the outer scope rather than the global
2146 of the same name. To avoid the warning, either rename the outer
2147 variable, or use a global statement in the inner function.
2148
Neil Schemenauera35c6882001-02-27 04:45:05 +00002149- An optional object allocator has been included. This allocator is
2150 optimized for Python objects and should be faster and use less memory
2151 than the standard system allocator. It is not enabled by default
2152 because of possible thread safety problems. The allocator is only
2153 protected by the Python interpreter lock and it is possible that some
2154 extension modules require a thread safe allocator. The object
2155 allocator can be enabled by providing the "--with-pymalloc" option to
2156 configure.
2157
Tim Petersd66595f2001-02-04 03:09:53 +00002158Standard library
2159
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002160- pyexpat now detects the expat version if expat.h defines it. A
2161 number of additional handlers are provided, which are only available
2162 since expat 1.95. In addition, the methods SetParamEntityParsing and
2163 GetInputContext of Parser objects are available with 1.95.x
2164 only. Parser objects now provide the ordered_attributes and
2165 specified_attributes attributes. A new module expat.model was added,
2166 which offers a number of additional constants if 1.95.x is used.
2167
2168- xml.dom offers the new functions registerDOMImplementation and
2169 getDOMImplementation.
2170
2171- xml.dom.minidom offers a toprettyxml method. A number of DOM
2172 conformance issues have been resolved. In particular, Element now
2173 has an hasAttributes method, and the handling of namespaces was
2174 improved.
2175
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002176- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2177 getting information about live Python code, and pydoc.py, a module
2178 for interactively converting docstrings to HTML or text.
2179 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002180 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002181 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2182 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002183
Tim Peters1eff7962001-03-01 02:31:33 +00002184- New library module difflib.py, primarily packaging the SequenceMatcher
2185 class at the heart of the popular ndiff.py file-comparison tool.
2186
2187- doctest.py (a framework for verifying Python code examples in docstrings)
2188 is now part of the std library.
2189
Tim Petersd66595f2001-02-04 03:09:53 +00002190Windows changes
2191
Guido van Rossume3955a82001-03-02 14:05:59 +00002192- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2193 small GUI that lets you browse the module docstrings using your
2194 default web browser.
2195
Tim Peters1eff7962001-03-01 02:31:33 +00002196- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2197 Platforms) is implemented. See
2198
2199 http://python.sourceforge.net/peps/pep-0235.html
2200
2201 for full details, especially the "Current Lower-Left Semantics" section.
2202 The new Windows import rules are simpler than before:
2203
2204 A. If the PYTHONCASEOK environment variable exists, same as
2205 before: silently accept the first case-insensitive match of any
2206 kind; raise ImportError if none found.
2207
2208 B. Else search sys.path for the first case-sensitive match; raise
2209 ImportError if none found.
2210
2211 The same rules have been implented on other platforms with case-
2212 insensitive but case-preserving filesystems too (including Cygwin, and
2213 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002214
Tim Peters25a9ce32001-02-19 07:06:36 +00002215- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2216 what it's supposed to do (and does do under NT and 2000) via direct
2217 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002218 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002219 all Win9x systems before.
2220
Tim Peters1eff7962001-03-01 02:31:33 +00002221- Build: Subproject _test (effectively) renamed to _testcapi.
2222
Tim Peters2fe289a2001-03-01 22:19:38 +00002223New platforms
2224
2225- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2226 Thanks to Steven Majewski!
2227
2228- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2229 Tishler!
2230
Guido van Rossum9089b272001-03-02 06:49:50 +00002231- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2232 Schwertberger! See RISCOS/README for more information -- it seems
2233 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002234 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002235
Tim Peters25a9ce32001-02-19 07:06:36 +00002236
Tim Petersd7b5e882001-01-25 03:36:26 +00002237What's New in Python 2.1 alpha 2?
2238=================================
Tim Peters40ead762001-01-27 05:35:26 +00002239
Tim Petersd7b5e882001-01-25 03:36:26 +00002240Core language, builtins, and interpreter
2241
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002242- Scopes nest. If a name is used in a function or class, but is not
2243 local, the definition in the nearest enclosing function scope will
2244 be used. One consequence of this change is that lambda statements
2245 could reference variables in the namespaces where the lambda is
2246 defined. In some unusual cases, this change will break code.
2247
2248 In all previous version of Python, names were resolved in exactly
2249 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002250 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002251 function A is defined within a function B, the names bound in B are
2252 not visible in A. The new rules make names bound in B visible in A,
2253 unless A contains a name binding that hides the binding in B.
2254
2255 Section 4.1 of the reference manual describes the new scoping rules
2256 in detail. The test script in Lib/test/test_scope.py demonstrates
2257 some of the effects of the change.
2258
2259 The new rules will cause existing code to break if it defines nested
2260 functions where an outer function has local variables with the same
2261 name as globals or builtins used by the inner function. Example:
2262
2263 def munge(str):
2264 def helper(x):
2265 return str(x)
2266 if type(str) != type(''):
2267 str = helper(str)
2268 return str.strip()
2269
2270 Under the old rules, the name str in helper() is bound to the
2271 builtin function str(). Under the new rules, it will be bound to
2272 the argument named str and an error will occur when helper() is
2273 called.
2274
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002275- The compiler will report a SyntaxError if "from ... import *" occurs
2276 in a function or class scope. The language reference has documented
2277 that this case is illegal, but the compiler never checked for it.
2278 The recent introduction of nested scope makes the meaning of this
2279 form of name binding ambiguous. In a future release, the compiler
2280 may allow this form when there is no possibility of ambiguity.
2281
Tim Peters40ead762001-01-27 05:35:26 +00002282- repr(string) is easier to read, now using hex escapes instead of octal,
2283 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2284
2285 >>> "\texample \r\n" + chr(0) + chr(255)
2286 '\texample \r\n\x00\xff' # in 2.1
2287 '\011example \015\012\000\377' # in 2.0
2288
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002289- Functions are now compared and hashed by identity, not by value, since
2290 the func_code attribute is writable.
2291
Fred Drakefb9d7122001-02-01 20:00:40 +00002292- Weak references (PEP 205) have been added. This involves a few
2293 changes in the core, an extension module (_weakref), and a Python
2294 module (weakref). The weakref module is the public interface. It
2295 includes support for "explicit" weak references, proxy objects, and
2296 mappings with weakly held values.
2297
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002298- A 'continue' statement can now appear in a try block within the body
2299 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002300 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002301
Tim Petersd7b5e882001-01-25 03:36:26 +00002302Standard library
2303
Barry Warsaw30dbd142001-01-31 22:14:01 +00002304- mailbox.py now has a new class, PortableUnixMailbox which is
2305 identical to UnixMailbox but uses a more portable scheme for
2306 determining From_ separators. Also, the constructors for all the
2307 classes in this module have a new optional `factory' argument, which
2308 is a callable used when new message classes must be instantiated by
2309 the next() method.
2310
Tim Petersd7b5e882001-01-25 03:36:26 +00002311- random.py is now self-contained, and offers all the functionality of
2312 the now-deprecated whrandom.py. See the docs for details. random.py
2313 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002314 and restoring the internal state of the generator; and jumpahead(n),
2315 for quickly forcing the internal state to be the same as if n calls to
2316 random() had been made. The latter is particularly useful for multi-
2317 threaded programs, creating one instance of the random.Random() class for
2318 each thread, then using .jumpahead() to force each instance to use a
2319 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002320
Tim Peters0de88fc2001-02-01 04:59:18 +00002321- random.py's seed() function is new. For bit-for-bit compatibility with
2322 prior releases, use the whseed function instead. The new seed function
2323 addresses two problems: (1) The old function couldn't produce more than
2324 about 2**24 distinct internal states; the new one about 2**45 (the best
2325 that can be done in the Wichmann-Hill generator). (2) The old function
2326 sometimes produced identical internal states when passed distinct
2327 integers, and there was no simple way to predict when that would happen;
2328 the new one guarantees to produce distinct internal states for all
2329 arguments in [0, 27814431486576L).
2330
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002331- The socket module now supports raw packets on Linux. The socket
2332 family is AF_PACKET.
2333
Tim Peters9ea17ac2001-02-02 05:57:15 +00002334- test_capi.py is a start at running tests of the Python C API. The tests
2335 are implemented by the new Modules/_testmodule.c.
2336
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002337- A new extension module, _symtable, provides provisional access to the
2338 internal symbol table used by the Python compiler. A higher-level
2339 interface will be added on top of _symtable in a future release.
2340
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002341- Removed the obsolete soundex module.
2342
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002343- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2344 the isSameNode method; NamedNodeMap the get method.
2345
2346- xml.sax.expatreader supports the lexical handler property; it
2347 generates comment, startCDATA, and endCDATA events.
2348
Tim Petersee826f82001-01-31 19:39:44 +00002349Windows changes
2350
2351- Build procedure: the zlib project is built in a different way that
2352 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002353 the zlib binary used. See PCbuild\readme.txt for details. Your old
2354 zlib-related directories can be deleted; you'll need to download fresh
2355 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002356
Tim Peters9ea17ac2001-02-02 05:57:15 +00002357- Build: New subproject _test for the benefit of test_capi.py (see above).
2358
Tim Petersb16c56f2001-02-02 21:24:51 +00002359- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2360 interface to some Python compiler internals).
2361
2362- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002363 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002364
Tim Petersa3a3a032000-11-30 05:22:44 +00002365What's New in Python 2.1 alpha 1?
2366=================================
2367
2368Core language, builtins, and interpreter
2369
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002370- There is a new Unicode companion to the PyObject_Str() API
2371 called PyObject_Unicode(). It behaves in the same way as the
2372 former, but assures that the returned value is an Unicode object
2373 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002374
Guido van Rossumf98eda02001-01-17 15:54:45 +00002375- The comparison operators support "rich comparison overloading" (PEP
2376 207). C extension types can provide a rich comparison function in
2377 the new tp_richcompare slot in the type object. The cmp() function
2378 and the C function PyObject_Compare() first try the new rich
2379 comparison operators before trying the old 3-way comparison. There
2380 is also a new C API PyObject_RichCompare() (which also falls back on
2381 the old 3-way comparison, but does not constrain the outcome of the
2382 rich comparison to a Boolean result).
2383
2384 The rich comparison function takes two objects (at least one of
2385 which is guaranteed to have the type that provided the function) and
2386 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2387 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2388 object, which may be NotImplemented (in which case the tp_compare
2389 slot function is used as a fallback, if defined).
2390
2391 Classes can overload individual comparison operators by defining one
2392 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002393 __ge__. There are no explicit "reflected argument" versions of
2394 these; instead, __lt__ and __gt__ are each other's reflection,
2395 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2396 reflection (similar at the C level). No other implications are
2397 made; in particular, Python does not assume that == is the Boolean
2398 inverse of !=, or that < is the Boolean inverse of >=. This makes
2399 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002400
2401 Classes or types that want to implement (in)equality tests but not
2402 the ordering operators (i.e. unordered types) should implement ==
2403 and !=, and raise an error for the ordering operators.
2404
Guido van Rossuma88479f2001-01-18 14:28:08 +00002405 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002406 Boolean; e.g. a matrix type might want to return a matrix of bits
2407 for A < B, giving elementwise comparisons. Such types should ensure
2408 that any interpretation of their value in a Boolean context raises
2409 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2410 at the C level) to always raise an exception.
2411
Guido van Rossuma88479f2001-01-18 14:28:08 +00002412- Complex numbers use rich comparisons to define == and != but raise
2413 an exception for <, <=, > and >=. Unfortunately, this also means
2414 that cmp() of two complex numbers raises an exception when the two
2415 numbers differ. Since it is not mathematically meaningful to compare
2416 complex numbers except for equality, I hope that this doesn't break
2417 too much code.
2418
Tim Peters3389f192001-02-18 08:48:49 +00002419- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002420 not defined by the language, other than that it's arbitrary but
2421 consistent (see the Reference Manual). An implementation detail changed
2422 in 2.1a1 such that None now compares less than any other object. Code
2423 relying on this new behavior (like code that relied on the previous
2424 behavior) does so at its own risk.
2425
Barry Warsaw573b5412001-01-15 20:43:18 +00002426- Functions and methods now support getting and setting arbitrarily
2427 named attributes (PEP 232). Functions have a new __dict__
2428 (a.k.a. func_dict) which hold the function attributes. Methods get
2429 and set attributes on their underlying im_func. It is a TypeError
2430 to set an attribute on a bound method.
2431
Guido van Rossum051e3352001-01-15 19:11:10 +00002432- The xrange() object implementation has been improved so that
2433 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2434 limitation that in this case len(xrange(sys.maxint)) can't be
2435 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2436 work fine as long as the index i doesn't actually reach 2**31.
2437 (Python uses regular ints for sequence and string indices; fixing
2438 that is much more work.)
2439
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002440- Two changes to from...import:
2441
Guido van Rossumba381232001-02-03 15:06:40 +00002442 1) "from M import X" now works even if (after loading module M)
2443 sys.modules['M'] is not a real module; it's basically a getattr()
2444 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002445
2446 2) "from M import *" now looks for M.__all__ to decide which names to
2447 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2448 filters out names starting with '_' as before. Whether or not
2449 __all__ exists, there's no restriction on the type of M.
2450
Guido van Rossumf61f1662001-01-10 20:13:55 +00002451- File objects have a new method, xreadlines(). This is the fastest
2452 way to iterate over all lines in a file:
2453
2454 for line in file.xreadlines():
2455 ...do something to line...
2456
2457 See the xreadlines module (mentioned below) for how to do this for
2458 other file-like objects.
2459
2460- Even if you don't use file.xreadlines(), you may expect a speedup on
2461 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002462 quite a bit in platform-specific ways: on systems (like Linux) that
2463 support flockfile(), getc_unlocked(), and funlockfile(), those are
2464 used by default. On systems (like Windows) without getc_unlocked(),
2465 a complicated (but still thread-safe) method using fgets() is used by
2466 default.
2467
Tim Petersd52269b2001-01-25 06:23:18 +00002468 You can force use of the fgets() method by #define'ing
2469 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002470 getc_unlocked()).
2471
Tim Petersd52269b2001-01-25 06:23:18 +00002472 You can force fgets() not to be used by #define'ing
2473 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002474 test_bufio.py fails -- and let us know if it does!).
2475
2476- In addition, the fileinput module, while still slower than the other
2477 methods on most platforms, has been sped up too, by using
2478 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002479
2480- Support for run-time warnings has been added, including a new
2481 command line option (-W) to specify the disposition of warnings.
2482 See the description of the warnings module below.
2483
2484- Extensive changes have been made to the coercion code. This mostly
2485 affects extension modules (which can now implement mixed-type
2486 numerical operators without having to use coercion), but
2487 occasionally, in boundary cases the coercion semantics have changed
2488 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002489 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002490 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002491 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002492
Guido van Rossumf98eda02001-01-17 15:54:45 +00002493- In connection with the coercion changes, a new built-in singleton
2494 object, NotImplemented is defined. This can be returned for
2495 operations that wish to indicate they are not implemented for a
2496 particular combination of arguments. From C, this is
2497 Py_NotImplemented.
2498
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002499- The interpreter accepts now bytecode files on the command line even
2500 if they do not have a .pyc or .pyo extension. On Linux, after executing
2501
Martin v. Löwise214baa2001-02-04 22:37:56 +00002502import imp,sys,string
2503magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2504reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2505open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002506
2507 any byte code file can be used as an executable (i.e. as an argument
2508 to execve(2)).
2509
Tim Peters9940b802000-12-01 07:59:35 +00002510- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002511 character. In 1.6 and earlier, they never produced a sign,
2512 and raised an error if the value of the long was too large
2513 to fit in a Python int. In 2.0, they produced a sign if and
2514 only if too large to fit in an int. This was inconsistent
2515 across platforms (because the size of an int varies across
2516 platforms), and inconsistent with hex() and oct(). Example:
2517
2518 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002519 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002520 'ffffffbe' # in 2.0 and before, on 32-bit machines
2521 >>> hex(-0x42L)
2522 '-0x42L' # in all versions of Python
2523
Tim Peters9940b802000-12-01 07:59:35 +00002524 The behavior of %d formats for negative Python longs remains
2525 the same as in 2.0 (although in 1.6 and before, they raised
2526 an error if the long didn't fit in a Python int).
2527
2528 %u formats don't make sense for Python longs, but are allowed
2529 and treated the same as %d in 2.1. In 2.0, a negative long
2530 formatted via %u produced a sign if and only if too large to
2531 fit in an int. In 1.6 and earlier, a negative long formatted
2532 via %u raised an error if it was too big to fit in an int.
2533
Guido van Rossum3661d392000-12-12 22:10:31 +00002534- Dictionary objects have an odd new method, popitem(). This removes
2535 an arbitrary item from the dictionary and returns it (in the form of
2536 a (key, value) pair). This can be useful for algorithms that use a
2537 dictionary as a bag of "to do" items and repeatedly need to pick one
2538 item. Such algorithms normally end up running in quadratic time;
2539 using popitem() they can usually be made to run in linear time.
2540
Tim Peters36cdad12000-12-29 02:06:45 +00002541Standard library
2542
Thomas Woutersfe385252001-01-19 23:16:56 +00002543- In the time module, the time argument to the functions strftime,
2544 localtime, gmtime, asctime and ctime is now optional, defaulting to
2545 the current time (in the local timezone).
2546
Guido van Rossumda91f222001-01-15 16:36:08 +00002547- The ftplib module now defaults to passive mode, which is deemed a
2548 more useful default given that clients are often inside firewalls
2549 these days. Note that this could break if ftplib is used to connect
2550 to a *server* that is inside a firewall, from outside; this is
2551 expected to be a very rare situation. To fix that, you can call
2552 ftp.set_pasv(0).
2553
Martin v. Löwis10a27872001-01-13 09:54:41 +00002554- The module site now treats .pth files not only for path configuration,
2555 but also supports extensions to the initialization code: Lines starting
2556 with import are executed.
2557
Guido van Rossumf61f1662001-01-10 20:13:55 +00002558- There's a new module, warnings, which implements a mechanism for
2559 issuing and filtering warnings. There are some new built-in
2560 exceptions that serve as warning categories, and a new command line
2561 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2562 turns warnings into errors). warnings.warn(message[, category])
2563 issues a warning message; this can also be called from C as
2564 PyErr_Warn(category, message).
2565
2566- A new module xreadlines was added. This exports a single factory
2567 function, xreadlines(). The intention is that this code is the
2568 absolutely fastest way to iterate over all lines in an open
2569 file(-like) object:
2570
2571 import xreadlines
2572 for line in xreadlines.xreadlines(file):
2573 ...do something to line...
2574
2575 This is equivalent to the previous the speed record holder using
2576 file.readlines(sizehint). Note that if file is a real file object
2577 (as opposed to a file-like object), this is equivalent:
2578
2579 for line in file.xreadlines():
2580 ...do something to line...
2581
Tim Peters36cdad12000-12-29 02:06:45 +00002582- The bisect module has new functions bisect_left, insort_left,
2583 bisect_right and insort_right. The old names bisect and insort
2584 are now aliases for bisect_right and insort_right. XXX_right
2585 and XXX_left methods differ in what happens when the new element
2586 compares equal to one or more elements already in the list: the
2587 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002588 right. Code that doesn't care where equal elements end up should
2589 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002590
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002591- The new curses.panel module wraps the panel library that forms part
2592 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2593
Guido van Rossumf61f1662001-01-10 20:13:55 +00002594- The SocketServer module now sets the allow_reuse_address flag by
2595 default in the TCPServer class.
2596
2597- A new function, sys._getframe(), returns the stack frame pointer of
2598 the caller. This is intended only as a building block for
2599 higher-level mechanisms such as string interpolation.
2600
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002601- The pyexpat module supports a number of new handlers, which are
2602 available only in expat 1.2. If invocation of a callback fails, it
2603 will report an additional frame in the traceback. Parser objects
2604 participate now in garbage collection. If expat reports an unknown
2605 encoding, pyexpat will try to use a Python codec; that works only
2606 for single-byte charsets. The parser type objects is exposed as
2607 XMLParserObject.
2608
2609- xml.dom now offers standard definitions for symbolic node type and
2610 exception code constants, and a hierarchy of DOM exceptions. minidom
2611 was adjusted to use them.
2612
2613- The conformance of xml.dom.minidom to the DOM specification was
2614 improved. It detects a number of additional error cases; the
2615 previous/next relationship works even when the tree is modified;
2616 Node supports the normalize() method; NamedNodeMap, DocumentType and
2617 DOMImplementation classes were added; Element supports the
2618 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2619 method.
2620
Guido van Rossumf61f1662001-01-10 20:13:55 +00002621Build issues
2622
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002623- For Unix (and Unix-compatible) builds, configuration and building of
2624 extension modules is now greatly automated. Rather than having to
2625 edit the Modules/Setup file to indicate which modules should be
2626 built and where their include files and libraries are, a
2627 distutils-based setup.py script now takes care of building most
2628 extension modules. All extension modules built this way are built
2629 as shared libraries. Only a few modules that must be linked
2630 statically are still listed in the Setup file; you won't need to
2631 edit their configuration.
2632
2633- Python should now build out of the box on Cygwin. If it doesn't,
2634 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002635
2636- Python now always uses its own (renamed) implementation of getopt()
2637 -- there's too much variation among C library getopt()
2638 implementations.
2639
2640- C++ compilers are better supported; the CXX macro is always set to a
2641 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002642
Tim Petersd92dfe02000-12-12 01:18:41 +00002643Windows changes
2644
2645- select module: By default under Windows, a select() call
2646 can specify no more than 64 sockets. Python now boosts
2647 this Microsoft default to 512. If you need even more than
2648 that, see the MS docs (you'll need to #define FD_SETSIZE
2649 and recompile Python from source).
2650
Guido van Rossumf61f1662001-01-10 20:13:55 +00002651- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2652 subdirectory is no more!
2653
Tim Petersa3a3a032000-11-30 05:22:44 +00002654
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002655What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002656=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002657
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002658Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002659changes are in the file HISTORY. If you are making the jump directly
2660from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2661HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002662
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002663Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2664the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2665http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002666
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002667--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002668
2669======================================================================
2670
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002671What's new in 2.0 (since release candidate 1)?
2672==============================================
2673
2674Standard library
2675
2676- The copy_reg module was modified to clarify its intended use: to
2677 register pickle support for extension types, not for classes.
2678 pickle() will raise a TypeError if it is passed a class.
2679
2680- Fixed a bug in gettext's "normalize and expand" code that prevented
2681 it from finding an existing .mo file.
2682
2683- Restored support for HTTP/0.9 servers in httplib.
2684
Tim Peters989b7b92000-10-16 20:24:53 +00002685- The math module was changed to stop raising OverflowError in case of
2686 underflow, and return 0 instead in underflow cases. Whether Python
2687 used to raise OverflowError in case of underflow was platform-
2688 dependent (it did when the platform math library set errno to ERANGE
2689 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002690
2691- Fixed a bug in StringIO that occurred when the file position was not
2692 at the end of the file and write() was called with enough data to
2693 extend past the end of the file.
2694
2695- Fixed a bug that caused Tkinter error messages to get lost on
2696 Windows. The bug was fixed by replacing direct use of
2697 interp->result with Tcl_GetStringResult(interp).
2698
2699- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2700 redirect response.
2701
2702- Several changes were made to distutils: Some debugging code was
2703 removed from util. Fixed the installer used when an external zip
2704 program (like WinZip) is not found; the source code for this
2705 installer is in Misc/distutils. check_lib() was modified to behave
2706 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2707 test for whether installed modules are on sys.path was changed to
2708 use both normcase() and normpath().
2709
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002710- Several minor bugs were fixed in the xml package (the minidom,
2711 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002712
2713- The regression test driver (regrtest.py) behavior when invoked with
2714 -l changed: It now reports a count of objects that are recognized as
2715 garbage but not freed by the garbage collector.
2716
Tim Peters989b7b92000-10-16 20:24:53 +00002717- The regression test for the math module was changed to test
2718 exceptional behavior when the test is run in verbose mode. Python
2719 cannot yet guarantee consistent exception behavior across platforms,
2720 so the exception part of test_math is run only in verbose mode, and
2721 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002722
2723Internals
2724
2725- PyOS_CheckStack() has been disabled on Win64, where it caused
2726 test_sre to fail.
2727
2728Build issues
2729
2730- Changed compiler flags, so that gcc is always invoked with -Wall and
2731 -Wstrict-prototypes. Users compiling Python with GCC should see
2732 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002733 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002734 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002735
Tim Petersa3a3a032000-11-30 05:22:44 +00002736- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002737
2738Tools and other miscellany
2739
2740- The compiler in Tools/compiler was updated to support the new
2741 language features introduced in 2.0: extended print statement, list
2742 comprehensions, and augmented assignments. The new compiler should
2743 also be backwards compatible with Python 1.5.2; the compiler will
2744 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002745 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002746
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002747What's new in 2.0 release candidate 1 (since beta 2)?
2748=====================================================
2749
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002750What is release candidate 1?
2751
2752We believe that release candidate 1 will fix all known bugs that we
2753intend to fix for the 2.0 final release. This release should be a bit
2754more stable than the previous betas. We would like to see even more
2755widespread testing before the final release, so we are producing this
2756release candidate. The final release will be exactly the same unless
2757any show-stopping (or brown bag) bugs are found by testers of the
2758release candidate.
2759
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002760All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002761to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002762
2763Core language, builtins, and interpreter
2764
2765- A bug that caused crashes when __coerce__ was used with augmented
2766 assignment, e.g. +=, was fixed.
2767
2768- Raise ZeroDivisionError when raising zero to a negative number,
2769 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2770 power operator and the result of math.pow(0.0, -2.0) will vary by
2771 platform. On Linux, it raises a ValueError.
2772
2773- A bug in Unicode string interpolation was fixed that occasionally
2774 caused errors with formats including "%%". For example, the
2775 following expression "%% %s" % u"abc" no longer raises a TypeError.
2776
2777- Compilation of deeply nested expressions raises MemoryError instead
2778 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2779
2780- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2781 rendering them useless. They are now written in binary mode again.
2782
2783Standard library
2784
2785- Keyword arguments are now accepted for most pattern and match object
2786 methods in SRE, the standard regular expression engine.
2787
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002788- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002789 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002790
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002791- Several bugs in the Unicode handling and error handling in _tkinter
2792 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002793
2794- Fix memory management errors in Merge() and Tkapp_Call() routines.
2795
2796- Several changes were made to cStringIO to make it compatible with
2797 the file-like object interface and with StringIO. If operations are
2798 performed on a closed object, an exception is raised. The truncate
2799 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002800 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002801
2802- There were many changes made to the linuxaudiodev module and its
2803 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002804 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002805
2806 Note that this module is named poorly, because it should work
2807 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002808 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002809
2810 The module now raises exceptions when errors occur instead of
2811 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2812 audio) and defines a getptr() method that calls the
2813 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2814
2815- The library_version attribute, introduced in an earlier beta, was
2816 removed because it can not be supported with early versions of the C
2817 readline library, which provides no way to determine the version at
2818 compile-time.
2819
2820- The binascii module is now enabled on Win64.
2821
Tim Peters46446d62000-10-09 21:19:31 +00002822- tokenize.py no longer suffers "recursion depth" errors when parsing
2823 programs with very long string literals.
2824
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002825Internals
2826
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002827- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002828 which is called when the interpreter starts up to determine where
2829 the standard library is installed. These vulnerabilities affect all
2830 previous versions of Python and can be exploited by setting very
2831 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2832 setuid Python script, although use of the wrapper in
2833 Misc/setuid-prog.c will eliminate the vulnerability.
2834
2835- Fixed garbage collection bugs in instance creation that were
2836 triggered when errors occurred during initialization. The solution,
2837 applied in cPickle and in PyInstance_New(), is to call
2838 PyObject_GC_Init() after the initialization of the object's
2839 container attributes is complete.
2840
2841- pyexpat adds definitions of PyModule_AddStringConstant and
2842 PyModule_AddObject if the Python version is less than 2.0, which
2843 provides compatibility with PyXML on Python 1.5.2.
2844
2845- If the platform has a bogus definition for LONG_BIT (the number of
2846 bits in a long), an error will be reported at compile time.
2847
2848- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2849 collection crashes and possibly other, unreported crashes.
2850
2851- Fixed a memory leak in _PyUnicode_Fini().
2852
2853Build issues
2854
2855- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002856 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002857 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002858
2859- The mmap.PAGESIZE constant is now initialized using sysconf when
2860 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2861
2862- The md5 file should now compile on all platforms.
2863
2864- The select module now compiles on platforms that do not define
2865 POLLRDNORM and related constants.
2866
2867- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002868 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002869
Jeremy Hylton10921202000-10-09 18:34:12 +00002870- BeOS: A number of changes were made to the build and installation
2871 process. ar-fake now operates on a directory of object files.
2872 dl_export.h is gone, and its macros now appear on the mwcc command
2873 line during build on PPC BeOS.
2874
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002875- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002876 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002877
2878- Cygwin: Support for shared libraries, Tkinter, and sockets.
2879
2880- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2881
2882Tools and other miscellany
2883
2884- Removed debugging prints from main used with freeze.
2885
Tim Peters46446d62000-10-09 21:19:31 +00002886- IDLE auto-indent no longer crashes when it encounters Unicode
2887 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002888
2889What's new in 2.0 beta 2 (since beta 1)?
2890========================================
2891
2892Core language, builtins, and interpreter
2893
Tim Peters482c0212000-09-26 06:33:09 +00002894- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002895 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002896
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002897- Add -h and -V command line options to print the usage message and
2898 Python version number and exit immediately.
2899
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002900- eval() and exec accept Unicode objects as code parameters.
2901
2902- getattr() and setattr() now also accept Unicode objects for the
2903 attribute name, which are converted to strings using the default
2904 encoding before lookup.
2905
2906- Multiplication on string and Unicode now does proper bounds
2907 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2908 string is too long."
2909
2910- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002911 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002912
Jeremy Hylton1b618592000-09-26 05:32:36 +00002913
2914Standard library and extensions
2915
Guido van Rossum5b08f132001-04-16 02:05:23 +00002916- socket module: the OpenSSL code now adds support for RAND_status()
2917 and EGD (Entropy Gathering Device).
2918
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002919- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002920 argument checking; it still takes no arguments.
2921
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002922- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002923
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002924- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002925
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002926- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002927
2928- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002929 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002930
2931- copy: Copy Unicode objects atomically.
2932
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002933- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002934
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002935- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002936
Fred Drake67233bc2000-09-26 16:40:27 +00002937- dbm: Add get() and setdefault() methods to dbm object. Add constant
2938 `library' to module that names the library used. Added doc strings
2939 and method names to error messages. Uses configure to determine
2940 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2941 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002942
2943- distutils: Update to version 0.9.3.
2944
2945- dl: Add several dl.RTLD_ constants.
2946
2947- fpectl: Now supported on FreeBSD.
2948
2949- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2950 found by the collector will be saved in gc.garbage. This is useful
2951 for debugging a program that creates reference cycles.
2952
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002953- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002954 of HTTP class. Do not close socket on zero-length response. Do not
2955 crash when server sends invalid content-length header.
2956
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002957- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002958
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002959- marshal: When reading a short, sign-extend on platforms where shorts
2960 are bigger than 16 bits. When reading a long, repair the unportable
2961 sign extension that was being done for 64-bit machines. (It assumed
2962 that signed right shift sign-extends.)
2963
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002964- operator: Add contains(), invert(), __invert__() as aliases for
2965 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002966
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002967- os: Add support for popen2() and popen3() on all platforms where
2968 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002969
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002970- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002971 clicking on a file in Explorer (or passing the file name to the
2972 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002973
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002974- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002975 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002976
2977- pickle: Now raises ValueError when an invalid pickle that contains
2978 a non-string repr where a string repr was expected. This behavior
2979 matches cPickle.
2980
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002981- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002982
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002983- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002984
2985- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002986 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002987 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002988
2989- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002990 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002991
2992- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002993 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002994 few cycles during startup since the first call to
2995 setdefaultencoding() will initialize the codec registry and the
2996 encodings package.
2997
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002998- socket: Support for size hint in readlines() method of object returned
2999 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003000
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003001- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003002 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003003 is followed by whitespace.
3004
Tim Petersa3a3a032000-11-30 05:22:44 +00003005- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003006
3007- struct: Check ranges for bytes and shorts.
3008
3009- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003010 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003011
3012- Tkinter: Image objects are now guaranteed to have unique ids. Set
3013 event.delta to zero if Tk version doesn't support mousewheel.
3014 Removed some debugging prints.
3015
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003016- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003017
Fred Drake67233bc2000-09-26 16:40:27 +00003018- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003019 which works around a bug in Norton AntiVirus 2000 that leads directly
3020 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003021
3022- xml: New version detection code allows PyXML to override standard
3023 XML package if PyXML version is greater than 0.6.1.
3024
Fred Drake64bb3802000-09-26 16:21:35 +00003025- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3026 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3027 tree only for nodes which are sufficiently interesting to a specific
3028 application. Does not provide the HTML-specific extensions. Still
3029 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003030
Fred Drake64bb3802000-09-26 16:21:35 +00003031- xml.sax: SAX 2 support for Python, including all the handler
3032 interfaces needed to process XML 1.0 compliant XML. Some
3033 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003034
Fred Drake64bb3802000-09-26 16:21:35 +00003035- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3036 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003037
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003038
Jeremy Hylton1b618592000-09-26 05:32:36 +00003039C API
3040
3041- Add three new convenience functions for module initialization --
3042 PyModule_AddObject(), PyModule_AddIntConstant(), and
3043 PyModule_AddStringConstant().
3044
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003045- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003046 removed and add #error to Python.h if NULL isn't defined after
3047 #include of stdio.h.
3048
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003049- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003050 backwards compatibility (at the source level) with old extensions.
3051
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003052- A wrapper API was added for signal() and sigaction(). Instead of
3053 either function, always use PyOS_getsig() to get a signal handler
3054 and PyOS_setsig() to set one. A new convenience typedef
3055 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003056
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003057- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003058 internal data buffer and size of a string object -- or the default
3059 encoded version of a Unicode object.
3060
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003061- PyString_Size() and PyString_AsString() accept Unicode objects.
3062
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003063- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003064 exists). INT_MAX and LONG_MAX will always be defined, even if
3065 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003066
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003067- PyFloat_FromString takes a second argument, pend, that was
3068 effectively useless. It is now officially useless but preserved for
3069 backwards compatibility. If the pend argument is not NULL, *pend is
3070 set to NULL.
3071
3072- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3073 for the attribute name. See note on getattr() above.
3074
3075- A few bug fixes to argument processing for Unicode.
3076 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3077 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3078 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003079 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003080
3081- Py_BuildValue accepts B format (for bgen-generated code).
3082
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003083
Jeremy Hylton1b618592000-09-26 05:32:36 +00003084Internals
3085
3086- On Unix, fix code for finding Python installation directory so that
3087 it works when argv[0] is a relative path.
3088
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003089- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003090 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003091 rather than by generating a copy of the object.
3092
Tim Peters482c0212000-09-26 06:33:09 +00003093- Several of the internal Unicode tables are much smaller now, and
3094 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003095
Jeremy Hylton97693b02000-09-26 17:42:51 +00003096- In the garbage collector: Fixed bug in collection of tuples. Fixed
3097 bug that caused some instances to be removed from the container set
3098 while they were still live. Fixed parsing in gc.set_debug() for
3099 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003100
3101- Fixed refcount problem in instance deallocation that only occurred
3102 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3103
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003104- On Windows, getpythonregpath is now protected against null data in
3105 registry key.
3106
3107- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003108 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003109
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003110
Jeremy Hylton1b618592000-09-26 05:32:36 +00003111Build and platform-specific issues
3112
3113- Better support of GNU Pth via --with-pth configure option.
3114
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003115- Python/C API now properly exposed to dynamically-loaded extension
3116 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003117
3118- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3119 Don't define MS_SYNC to be zero when it is undefined. Added missing
3120 prototypes in posixmodule.c.
3121
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003122- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003123 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003124
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003125- Fix largefile support on older NetBSD systems and OpenBSD by adding
3126 define for TELL64.
3127
3128
3129Tools and other miscellany
3130
3131- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3132
3133- freeze: The modulefinder now works with 2.0 opcodes.
3134
Tim Petersa3a3a032000-11-30 05:22:44 +00003135- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003136 Move hackery of sys.argv until after the Tk instance has been
3137 created, which allows the application-specific Tkinter
3138 initialization to be executed if present; also pass an explicit
3139 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003140
Jeremy Hylton1b618592000-09-26 05:32:36 +00003141
3142What's new in 2.0 beta 1?
3143=========================
3144
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003145Source Incompatibilities
3146------------------------
3147
3148None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3149such as single-argument append(), connect() and bind(), and changes to
3150str(long) and repr(float).
3151
3152
3153Binary Incompatibilities
3154------------------------
3155
3156- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3157with Python 2.0; these extensions will have to be rebuilt for Python
31582.0.
3159
3160- On Windows, attempting to import a third party extension built for
3161Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3162can do about this. Check your PYTHONPATH environment variable!
3163
3164- Python bytecode files (*.pyc and *.pyo) are not compatible between
3165releases.
3166
3167
3168Overview of Changes Since 1.6
3169-----------------------------
3170
3171There are many new modules (including brand new XML support through
3172the xml package, and i18n support through the gettext module); a list
3173of all new modules is included below. Lots of bugs have been fixed.
3174
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003175The process for making major new changes to the language has changed
3176since Python 1.6. Enhancements must now be documented by a Python
3177Enhancement Proposal (PEP) before they can be accepted.
3178
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003179There are several important syntax enhancements, described in more
3180detail below:
3181
3182 - Augmented assignment, e.g. x += 1
3183
3184 - List comprehensions, e.g. [x**2 for x in range(10)]
3185
3186 - Extended import statement, e.g. import Module as Name
3187
3188 - Extended print statement, e.g. print >> file, "Hello"
3189
3190Other important changes:
3191
3192 - Optional collection of cyclical garbage
3193
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003194Python Enhancement Proposal (PEP)
3195---------------------------------
3196
3197PEP stands for Python Enhancement Proposal. A PEP is a design
3198document providing information to the Python community, or describing
3199a new feature for Python. The PEP should provide a concise technical
3200specification of the feature and a rationale for the feature.
3201
3202We intend PEPs to be the primary mechanisms for proposing new
3203features, for collecting community input on an issue, and for
3204documenting the design decisions that have gone into Python. The PEP
3205author is responsible for building consensus within the community and
3206documenting dissenting opinions.
3207
3208The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003209
3210Augmented Assignment
3211--------------------
3212
3213This must have been the most-requested feature of the past years!
3214Eleven new assignment operators were added:
3215
Guido van Rossume905e952000-09-05 12:42:46 +00003216 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003217
3218For example,
3219
3220 A += B
3221
3222is similar to
3223
3224 A = A + B
3225
3226except that A is evaluated only once (relevant when A is something
3227like dict[index].attr).
3228
3229However, if A is a mutable object, A may be modified in place. Thus,
3230if A is a number or a string, A += B has the same effect as A = A+B
3231(except A is only evaluated once); but if a is a list, A += B has the
3232same effect as A.extend(B)!
3233
3234Classes and built-in object types can override the new operators in
3235order to implement the in-place behavior; the not-in-place behavior is
3236used automatically as a fallback when an object doesn't implement the
3237in-place behavior. For classes, the method name is derived from the
3238method name for the corresponding not-in-place operator by inserting
3239an 'i' in front of the name, e.g. __iadd__ implements in-place
3240__add__.
3241
3242Augmented assignment was implemented by Thomas Wouters.
3243
3244
3245List Comprehensions
3246-------------------
3247
3248This is a flexible new notation for lists whose elements are computed
3249from another list (or lists). The simplest form is:
3250
3251 [<expression> for <variable> in <sequence>]
3252
Guido van Rossum56db0952000-09-06 23:34:25 +00003253For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003254This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003255
3256You can also add a condition:
3257
3258 [<expression> for <variable> in <sequence> if <condition>]
3259
3260For example, [w for w in words if w == w.lower()] would yield the list
3261of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003262than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003263
3264You can also have nested for loops and more than one 'if' clause. For
3265example, here's a function that flattens a sequence of sequences::
3266
3267 def flatten(seq):
3268 return [x for subseq in seq for x in subseq]
3269
3270 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3271
3272This prints
3273
3274 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3275
3276List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003277Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003278
3279
3280Extended Import Statement
3281-------------------------
3282
3283Many people have asked for a way to import a module under a different
3284name. This can be accomplished like this:
3285
3286 import foo
3287 bar = foo
3288 del foo
3289
3290but this common idiom gets old quickly. A simple extension of the
3291import statement now allows this to be written as follows:
3292
3293 import foo as bar
3294
3295There's also a variant for 'from ... import':
3296
3297 from foo import bar as spam
3298
3299This also works with packages; e.g. you can write this:
3300
3301 import test.regrtest as regrtest
3302
3303Note that 'as' is not a new keyword -- it is recognized only in this
3304context (this is only possible because the syntax for the import
3305statement doesn't involve expressions).
3306
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003307Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003308
3309
3310Extended Print Statement
3311------------------------
3312
3313Easily the most controversial new feature, this extension to the print
3314statement adds an option to make the output go to a different file
3315than the default sys.stdout.
3316
3317For example, to write an error message to sys.stderr, you can now
3318write:
3319
3320 print >> sys.stderr, "Error: bad dog!"
3321
3322As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003323evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003324
3325 print >> None, "Hello world"
3326
3327is equivalent to
3328
3329 print "Hello world"
3330
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003331Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003332
3333
3334Optional Collection of Cyclical Garbage
3335---------------------------------------
3336
3337Python is now equipped with a garbage collector that can hunt down
3338cyclical references between Python objects. It's no replacement for
3339reference counting; in fact, it depends on the reference counts being
3340correct, and decides that a set of objects belong to a cycle if all
3341their reference counts can be accounted for from their references to
3342each other. This devious scheme was first proposed by Eric Tiedemann,
3343and brought to implementation by Neil Schemenauer.
3344
3345There's a module "gc" that lets you control some parameters of the
3346garbage collection. There's also an option to the configure script
3347that lets you enable or disable the garbage collection. In 2.0b1,
3348it's on by default, so that we (hopefully) can collect decent user
3349experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003350performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003351off by default in the final 2.0 release.
3352
3353
3354Smaller Changes
3355---------------
3356
3357A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3358map(None, seq1, seq2, ...) when the sequences have the same length;
3359i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3360the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003361zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003362
3363sys.version_info is a tuple (major, minor, micro, level, serial).
3364
3365Dictionaries have an odd new method, setdefault(key, default).
3366dict.setdefault(key, default) returns dict[key] if it exists; if not,
3367it sets dict[key] to default and returns that value. Thus:
3368
3369 dict.setdefault(key, []).append(item)
3370
3371does the same work as this common idiom:
3372
3373 if not dict.has_key(key):
3374 dict[key] = []
3375 dict[key].append(item)
3376
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003377There are two new variants of SyntaxError that are raised for
3378indentation-related errors: IndentationError and TabError.
3379
3380Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3381escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003382
3383The limits on the size of expressions and file in Python source code
3384have been raised from 2**16 to 2**32. Previous versions of Python
3385were limited because the maximum argument size the Python VM accepted
3386was 2**16. This limited the size of object constructor expressions,
3387e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3388limit was raised thanks to a patch by Charles Waldman that effectively
3389fixes the problem. It is now much more likely that you will be
3390limited by available memory than by an arbitrary limit in Python.
3391
3392The interpreter's maximum recursion depth can be modified by Python
3393programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3394limit is the maximum number of recursive calls that can be made by
3395Python code. The limit exists to prevent infinite recursion from
3396overflowing the C stack and causing a core dump. The default value is
33971000. The maximum safe value for a particular platform can be found
3398by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003399
3400New Modules and Packages
3401------------------------
3402
3403atexit - for registering functions to be called when Python exits.
3404
3405imputil - Greg Stein's alternative API for writing custom import
3406hooks.
3407
3408pyexpat - an interface to the Expat XML parser, contributed by Paul
3409Prescod.
3410
3411xml - a new package with XML support code organized (so far) in three
3412subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3413would fill a volume. There's a special feature whereby a
3414user-installed package named _xmlplus overrides the standard
3415xmlpackage; this is intended to give the XML SIG a hook to distribute
3416backwards-compatible updates to the standard xml package.
3417
3418webbrowser - a platform-independent API to launch a web browser.
3419
3420
Guido van Rossume905e952000-09-05 12:42:46 +00003421Changed Modules
3422---------------
3423
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003424array -- new methods for array objects: count, extend, index, pop, and
3425remove
3426
3427binascii -- new functions b2a_hex and a2b_hex that convert between
3428binary data and its hex representation
3429
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003430calendar -- Many new functions that support features including control
3431over which day of the week is the first day, returning strings instead
3432of printing them. Also new symbolic constants for days of week,
3433e.g. MONDAY, ..., SUNDAY.
3434
3435cgi -- FieldStorage objects have a getvalue method that works like a
3436dictionary's get method and returns the value attribute of the object.
3437
3438ConfigParser -- The parser object has new methods has_option,
3439remove_section, remove_option, set, and write. They allow the module
3440to be used for writing config files as well as reading them.
3441
3442ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003443optionally support the RFC 959 REST command.
3444
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003445gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003446
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003447httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3448the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003449
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003450locale -- implement getdefaultlocale for Win32 and Macintosh
3451
3452marshal -- no longer dumps core when marshaling deeply nested or
3453recursive data structures
3454
3455os -- new functions isatty, seteuid, setegid, setreuid, setregid
3456
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003457os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3458support under Unix.
3459
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003460os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003461
3462os.path -- fix semantics of os.path.commonprefix
3463
3464smtplib -- support for sending very long messages
3465
3466socket -- new function getfqdn()
3467
3468readline -- new functions to read, write and truncate history files.
3469The readline section of the library reference manual contains an
3470example.
3471
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003472select -- add interface to poll system call
3473
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003474shutil -- new copyfileobj function
3475
3476SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3477HTTP server.
3478
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003479Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003480
3481urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003482e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003483
3484whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003485
3486
3487Obsolete Modules
3488----------------
3489
3490None. However note that 1.6 made a whole slew of modules obsolete:
3491stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3492poly, zmod, strop, util, whatsound.
3493
3494
3495Changed, New, Obsolete Tools
3496----------------------------
3497
Tim Peters8b092332000-09-05 20:15:25 +00003498None.
Guido van Rossume905e952000-09-05 12:42:46 +00003499
3500
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003501C-level Changes
3502---------------
3503
3504Several cleanup jobs were carried out throughout the source code.
3505
3506All C code was converted to ANSI C; we got rid of all uses of the
3507Py_PROTO() macro, which makes the header files a lot more readable.
3508
3509Most of the portability hacks were moved to a new header file,
3510pyport.h; several other new header files were added and some old
3511header files were removed, in an attempt to create a more rational set
3512of header files. (Few of these ever need to be included explicitly;
3513they are all included by Python.h.)
3514
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003515Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003516and Win64, especially for the new Intel Itanium processor. Mick also
3517added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003518
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003519The C APIs to return an object's size have been update to consistently
3520use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3521previous versions, the abstract interfaces used PyXXX_Length and the
3522concrete interfaces used PyXXX_Size. The old names,
3523e.g. PyObject_Length, are still available for backwards compatibility
3524at the API level, but are deprecated.
3525
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003526The PyOS_CheckStack function has been implemented on Windows by
3527Fredrik Lundh. It prevents Python from failing with a stack overflow
3528on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003529
3530The GC changes resulted in creation of two new slots on object,
3531tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003532the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003533
3534The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003535C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003536
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003537PyErr_Format has been updated to automatically calculate the size of
3538the buffer needed to hold the formatted result string. This change
3539prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003540
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003541New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003542
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003543PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3544that are the same as their non-Ex counterparts except they take an
3545extra flag argument that tells them to close the file when done.
3546
3547XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003548
Tim Peters8b092332000-09-05 20:15:25 +00003549
3550Windows Changes
3551---------------
3552
3553New popen2/popen3/peopen4 in os module (see Changed Modules above).
3554
3555os.popen is much more usable on Windows 95 and 98. See Microsoft
3556Knowledge Base article Q150956. The Win9x workaround described there
3557is implemented by the new w9xpopen.exe helper in the root of your
3558Python installation. Note that Python uses this internally; it is not
3559a standalone program.
3560
3561Administrator privileges are no longer required to install Python
3562on Windows NT or Windows 2000. If you have administrator privileges,
3563Python's registry info will be written under HKEY_LOCAL_MACHINE.
3564Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003565under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003566uses of Python, but will prevent some advanced uses from working
3567(for example, running a Python script as an NT service, or possibly
3568from CGI).
3569
3570[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3571installer; instead, it installs the needed Tcl/Tk files directly in the
3572Python directory. If you already have a Tcl/Tk installation, this
3573wastes some disk space (about 4 Megs) but avoids problems with
3574conflicting Tcl/Tk installations, and makes it much easier for Python
3575to ensure that Tcl/Tk can find all its files.
3576
3577[This was new in 1.6] The Windows installer now installs by default in
3578\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3579
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003580
3581Updates to the changes between 1.5.2 and 1.6
3582--------------------------------------------
3583
3584The 1.6 NEWS file can't be changed after the release is done, so here
3585is some late-breaking news:
3586
3587New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3588and changes to getlocale() and setlocale().
3589
3590The new module is now enabled per default.
3591
3592It is not true that the encodings codecs cannot be used for normal
3593strings: the string.encode() (which is also present on 8-bit strings
3594!) allows using them for 8-bit strings too, e.g. to convert files from
3595cp1252 (Windows) to latin-1 or vice-versa.
3596
3597Japanese codecs are available from Tamito KAJIYAMA:
3598http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3599
3600
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003601======================================================================