blob: 3156376a4aa7578778c3b0242efed920021801b3 [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
Mark Hammonda5083ec2002-07-22 12:53:16 +00008- The public Python C API will generally be declared using PyAPI_FUNC
9 and PyAPI_DATA macros, while Python extension module init functions
10 will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
11 are deprecated.
Tim Petersaf8446f2001-12-21 21:36:50 +000012
Mark Hammondc0e35152002-07-16 01:32:30 +000013- Ctrl+C handling on Windows has been made more consistent with
14 other platforms. KeyboardInterrupt can now reliably be caught,
15 and Ctrl+C at an interative prompt no longer terminates the
16 process under NT/2k/XP (it never did under Win9x). Ctrl+C will
17 interrupt time.sleep() in the main thread, and any child processes
18 created via the popen family are also interrupted (as generally
19 happens on for Linux/Unix). [SF bugs 231273, 439992 and 581232]
20
Raymond Hettinger5a04aec2002-06-25 00:25:30 +000021- Slices and repetitions of buffer objects now consistently return
22 a string. Formerly, strings would be returned most of the time,
23 but a buffer object would be returned when the repetition count
24 was one or when the slice range was all inclusive.
25
Guido van Rossumc7c36502002-06-21 01:29:25 +000026- The __slots__ variable can now mention "private" names, and the
27 right thing will happen (e.g. __slots__ = ["__foo"]).
28
Walter Dörwald3430d702002-06-17 10:43:59 +000029- Unicode objects in sys.path are no longer ignored but treated
30 as directory names.
31
Guido van Rossum9562bcf2002-06-14 21:31:18 +000032- The built-ins slice() and buffer() are now callable types. The
33 types classobj (formerly class), code, function, instance, and
34 instancemethod (formerly instance-method), which have no built-in
35 names but are accessible through the types module, are now also
36 callable. The type dict-proxy is renamed to dictproxy.
37
Neal Norwitz1f68fc72002-06-14 00:50:42 +000038- Fixed string.startswith and string.endswith builtin methods
39 so they accept negative indices. [SF bug 493951]
40
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +000041- Fixed a bug with a continue inside a try block and a yield in the
42 finally clause. [SF bug 567538]
43
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000044- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000045 with a third "stride" parameter. For example, "hello world"[::-1]
46 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000047
Guido van Rossum9f7549b2002-06-10 21:39:42 +000048- Cycles going through the __class__ link of a new-style instance are
49 now detected by the garbage collector.
50
Guido van Rossum9923ffe2002-06-04 19:52:53 +000051- Classes using __slots__ are now properly garbage collected.
52 [SF bug 519621]
53
54- Tightened the __slots__ rules: a slot name must be a valid Python
55 identifier.
56
Guido van Rossum2e4e0262002-06-04 05:58:34 +000057- The constructor for the module type now requires a name argument and
58 takes an optional docstring argument. Previously, this constructor
59 ignored its arguments. As a consequence, deriving a class from a
60 module (not from the module type) is now illegal; previously this
61 created an unnamed module, just like invoking the module type did.
62 [SF bug 563060]
63
Neal Norwitzd68f5172002-05-29 15:54:55 +000064- A new warning PendingDeprecationWarning was added to provide
65 direction on features which are in the process of being deprecated.
66 The warning will not be printed by default. To see the pending
67 deprecations, use -Walways::PendingDeprecationWarning::
68 as a command line option or warnings.filterwarnings() in code.
69
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000070- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000071 for 'str' and 'unicode', and can be used instead of
72 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000073 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000074 is an abstract base class and cannot be instantiated directly.
75
Fred Draked0ba6362002-05-02 21:28:26 +000076- Deprecated features of xrange objects have been removed as
77 promised. The start, stop, and step attributes and the tolist()
78 method no longer exist. xrange repetition and slicing have been
79 removed.
80
Guido van Rossum7dab2422002-04-26 19:40:56 +000081- New builtin function enumerate(x), from PEP 279. Example:
82 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
83 The argument can be an arbitrary iterable object.
84
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000085- The assert statement no longer tests __debug__ at runtime. This means
86 that assert statements cannot be disabled by assigning a false value
87 to __debug__.
88
Walter Dörwald068325e2002-04-15 13:36:47 +000089- A method zfill() was added to str and unicode, that fills a numeric
90 string to the left with zeros. For example,
91 "+123".zfill(6) -> "+00123".
92
Guido van Rossum862fe3c2002-04-15 12:36:47 +000093- Complex numbers supported divmod() and the // and % operators, but
94 these make no sense. Since this was documented, they're being
95 deprecated now.
96
Guido van Rossum26dd8302002-04-26 20:11:29 +000097- String and unicode methods lstrip(), rstrip() and strip() now take
98 an optional argument that specifies the characters to strip. For
99 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +0000100
Guido van Rossumc69343b2002-04-12 19:22:48 +0000101- Added a new dict method pop(key). This removes and returns the
102 value corresponding to key. [SF patch #539949]
103
Guido van Rossum8ace1ab2002-04-06 01:05:01 +0000104- Changed new-style class instantiation so that when C's __new__
105 method returns something that's not a C instance, its __init__ is
106 not called. [SF bug #537450]
107
Guido van Rossum181e41a2002-04-06 00:23:25 +0000108- Fixed super() to work correctly with class methods. [SF bug #535444]
109
Guido van Rossum47834462002-04-04 15:21:33 +0000110- A new built-in type, bool, has been added, as well as built-in
111 names for its two values, True and False. Comparisons and sundry
112 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000113 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +0000114 is backward compatible.
115
Guido van Rossum95b62a62002-03-29 01:07:24 +0000116- Fixed two bugs reported as SF #535905: under certain conditions,
117 deallocating a deeply nested structure could cause a segfault in the
118 garbage collector, due to interaction with the "trashcan" code;
119 access to the current frame during destruction of a local variable
120 could access a pointer to freed memory.
121
Guido van Rossumfe0ca4a2002-06-18 21:20:13 +0000122- The optional object allocator ("pymalloc") has been enabled by
123 default. The recommended practice for memory allocation and
124 deallocation has been streamlined. A header file is included,
125 Misc/pymemcompat.h, which can be bundled with 3rd party extensions
126 and lets them use the same API with Python versions from 1.5.2
127 onwards.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000128
Guido van Rossum8c842552002-03-14 23:05:54 +0000129- If you try to pickle an instance of a class that has __slots__ but
130 doesn't define or override __getstate__, a TypeError is now raised.
131 This is done by adding a bozo __getstate__ to the class that always
132 raises TypeError. (Before, this would appear to be pickled, but the
133 state of the slots would be lost.)
134
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +0000135- PyErr_Display will provide file and line information for all exceptions
136 that have an attribute print_file_and_line, not just SyntaxErrors.
137
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000138- The UTF-8 codec will now encode and decode Unicode surrogates
139 correctly and without raising exceptions for unpaired ones.
140
Neal Norwitz649b7592002-01-01 19:07:13 +0000141- file.xreadlines() now raises a ValueError if the file is closed:
142 Previously, an xreadlines object was returned which would raise
143 a ValueError when the xreadlines.next() method was called.
144
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000145- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000146 An exception will now be raised if more than one argument is used.
147
Tim Petersaf8446f2001-12-21 21:36:50 +0000148Extension modules
149
Guido van Rossum9562bcf2002-06-14 21:31:18 +0000150- The 'new' module is no longer an extension, but a Python module that
151 only exists for backwards compatibility. Its contents are no longer
152 functions but callable type objects.
153
Tim Peters81b92512002-04-29 01:37:32 +0000154- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000155 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000156 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000157
Martin v. Löwis606edc12002-06-13 21:09:11 +0000158- posix.killpg, posix.mknod, and posix.getpgid have been added where
159 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000160
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000161- The locale module now exposes the C library's gettext interface.
162
Tim Petersfbf74f22002-03-14 19:06:01 +0000163- A security hole ("double free") was found in zlib-1.1.3, a popular
164 third party compression library used by some Python modules. The
165 hole was quickly plugged in zlib-1.1.4, and the Windows build of
166 Python now ships with zlib-1.1.4.
167
Martin v. Löwis688357e2002-04-08 21:28:20 +0000168- pwd, grp, and resource return enhanced tuples now, with symbolic
169 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000170
Martin v. Löwis99866332002-03-01 10:27:01 +0000171- array.array is now a type object. A new format character
172 'u' indicates Py_UNICODE arrays. For those, .tounicode and
173 .fromunicode methods are available. Arrays now support __iadd__
174 and __imul__.
175
Neal Norwitze790eae2002-01-01 21:14:12 +0000176- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000177 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
178 is called.
179
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000180- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
181 been added where available.
182
Tim Petersaf8446f2001-12-21 21:36:50 +0000183Library
184
Marc-André Lemburg58e2ff22002-07-12 14:40:04 +0000185- New encoding for the Palm OS character set: palmos.
186
Tim Peters943382c2002-07-07 03:59:34 +0000187- binascii.crc32() and the zipfile module had problems on some 64-bit
188 platforms. These have been fixed. On a platform with 8-byte C longs,
189 crc32() now returns a signed-extended 4-byte result, so that its value
190 as a Python int is equal to the value computed a 32-bit platform.
191
Martin v. Löwis7d650ca2002-06-30 15:05:00 +0000192- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
193 argument.
194
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000195- Some fixes in the copy module: when an object is copied through its
196 __reduce__ method, there was no check for a __setstate__ method on
197 the result [SF patch 565085]; deepcopy should treat instances of
198 custom metaclasses the same way it treats instances of type 'type'
199 [SF patch 560794].
200
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000201- Sockets now support timeout mode. After s.settimeout(T), where T is
202 a float expressing seconds, subsequent operations raise an exception
203 if they cannot be completed within T seconds. To disable timeout
204 mode, use s.settimeout(None).
205
206- getopt.gnu_getopt was added. This supports GNU-style option
207 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000208
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000209- Stop using strings for exceptions. String objects used for
210 exceptions are now classes deriving from Exception. The objects
211 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
212 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000213
Walter Dörwald474458d2002-06-04 15:16:29 +0000214- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
215 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
216 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
217 big endian systems were added to the codecs module. The old names
218 BOM32_* and BOM64_* were off by a factor of 2.
219
Guido van Rossumf9257822002-06-18 20:43:18 +0000220- Added conversion functions math.degrees() and math.radians().
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000221
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000222- ftplib.retrlines() now tests for callback is None rather than testing
223 for False. Was causing an error when given a callback object which
224 was callable but also returned len() as zero. The change may
225 create new breakage if the caller relied on the undocumented behavior
226 and called with callback set to [] or some other False value not
227 identical to None.
228
Tim Peters46c04e12002-05-05 20:40:00 +0000229- random.gauss() uses a piece of hidden state used by nothing else,
230 and the .seed() and .whseed() methods failed to reset it. In other
231 words, setting the seed didn't completely determine the sequence of
232 results produced by random.gauss(). It does now. Programs repeatedly
233 mixing calls to a seed method with calls to gauss() may see different
234 results now.
235
Fred Drake7f781c92002-05-01 20:33:53 +0000236- The pickle.Pickler class grew a clear_memo() method to mimic that
237 provided by cPickle.Pickler.
238
Tim Peters81b92512002-04-29 01:37:32 +0000239- difflib's SequenceMatcher class now does a dynamic analysis of
240 which elements are so frequent as to constitute noise. For
241 comparing files as sequences of lines, this generally works better
242 than the IS_LINE_JUNK function, and function ndiff's linejunk
243 argument defaults to None now as a result. A happy benefit is
244 that SequenceMatcher may run much faster now when applied
245 to large files with many duplicate lines (for example, C program
246 text with lots of repeated "}" and "return NULL;" lines).
247
Guido van Rossum256705b2002-04-23 13:29:43 +0000248- New Text.dump() method in Tkinter module.
249
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000250- New distutils commands for building packagers were added to
251 support pkgtool on Solaris and swinstall on HP-UX.
252
253- distutils now has a new abstract binary packager base class
254 command/bdist_packager, which simplifies writing packagers.
255 This will hopefully provide the missing bits to encourage
256 people to submit more packagers, e.g. for Debian, FreeBSD
257 and other systems.
258
Guido van Rossumf9257822002-06-18 20:43:18 +0000259- The UTF-16, -LE and -BE stream readers now raise a
260 NotImplementedError for all calls to .readline(). Previously, they
261 used to just produce garbage or fail with an encoding error --
262 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 +0000263 work well with these.
264
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000265- compileall now supports quiet operation.
266
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000267- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000268 connections.
269
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000270- socket module: the SSL support was broken out of the main
271 _socket module C helper and placed into a new _ssl helper
272 which now gets imported by socket.py if available and working.
273
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000274- encodings package: added aliases for all supported IANA character
275 sets
276
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000277- ftplib: to safeguard the user's privacy, anonymous login will use
278 "anonymous@" as default password, rather than the real user and host
279 name.
280
Fred Drake36736122002-01-10 13:50:31 +0000281- webbrowser: tightened up the command passed to os.system() so that
282 arbitrary shell code can't be executed because a bogus URL was
283 passed in.
284
Tim Peters11bd9942002-02-01 00:52:29 +0000285- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000286 gettext.find an optional all argument. Translations will now fallback
287 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000288
Martin v. Löwis9668b932002-01-12 11:27:42 +0000289- distutils bdist commands now offer a --skip-build option.
290
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000291- warnings.warn now accepts a Warning instance as first argument.
292
Fred Drakefed7e852002-04-04 19:36:15 +0000293- The xml.sax.expatreader.ExpatParser class will no longer create
294 circular references by using itself as the locator that gets passed
295 to the content handler implementation. [SF bug #535474]
296
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000297- The email.Parser.Parser class now properly parses strings regardless
298 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
299 or CRLF). Also, the Header class's constructor default arguments
300 has changed slightly so that an explicit maxlinelen value is always
301 honored.
302
Tim Petersaf8446f2001-12-21 21:36:50 +0000303Tools/Demos
304
Marc-André Lemburg46260092002-04-04 16:17:11 +0000305- freeze.py now produces binaries which can import shared modules,
306 unlike before when this failed due to missing symbol exports in
307 the generated binary.
308
Tim Petersaf8446f2001-12-21 21:36:50 +0000309Build
310
Tim Petersc6a3ff62002-07-08 22:11:52 +0000311- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
312 get into infinite loops, when a new-style class got garbage-collected.
313 Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
314 that new-style classes be immortal in COUNT_ALLOCS builds. Note that
315 COUNT_ALLOCS is not enabled by default, in either release or debug
316 builds, and that new-style classes are immortal only in COUNT_ALLOCS
317 builds.
318
Tim Peters943382c2002-07-07 03:59:34 +0000319- Compiling out the cyclic garbage collector is no longer an option.
320 The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
321 that it's always defined (for the benefit of any extension modules
322 that may be conditionalizing on it). A bonus is that any extension
323 type participating in cyclic gc can choose to participate in the
324 Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
325 to require editing the core to teach the trashcan mechanism about the
326 new type.
327
Tim Peters1de41bf2002-07-03 03:31:20 +0000328- Accoring to Annex F of the current C standard,
329
330 The Standard C macro HUGE_VAL and its float and long double analogs,
331 HUGE_VALF and HUGE_VALL, expand to expressions whose values are
332 positive infinities.
333
334 Python only uses the double HUGE_VAL, and only to #define its own symbol
335 Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
336 pyport.h used to try to worm around that, but the workarounds triggered
337 other bugs on other platforms, so we gave up. If your platform defines
338 HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
339 that works on your platform. The only instance of this I'm sure about
340 is on an unknown subset of Cray systems, described here:
341
342 http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
343
344 Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
345
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000346- The configure option --without-doc-strings can be used to remove the
347 doc strings from the builtin functions and modules; this reduces the
348 size of the executable.
349
Tim Peters639295f2002-04-21 07:30:30 +0000350- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
351 say how or when to configure it, or how to turn it off.
352
Martin v. Löwis1142de32002-03-29 16:28:31 +0000353- On Unix, a shared libpython2.3.so can be created with --enable-shared.
354
Tim Peters8deda702002-03-30 10:06:07 +0000355- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
356 preprocessor symbols were eliminated. The internal decisions they
357 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000358
Fred Drake7d28b732002-05-02 21:17:00 +0000359- The tools used to build the documentation now work under Cygwin as
360 well as Unix.
361
Skip Montanaro57454e52002-06-14 20:30:31 +0000362- The bsddb and dbm module builds have been changed to try and avoid version
363 skew problems and disable linkage with Berkeley DB 1.85 unless the
364 installer knows what s/he's doing. See the section on building these
365 modules in the README file for details.
366
Tim Petersaf8446f2001-12-21 21:36:50 +0000367C API
368
Tim Peters7c321a82002-07-09 02:57:01 +0000369- Py_FatalError() is now declared as taking a const char* argument. It
370 was previously declared without const. This should not affect working
371 code.
372
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000373- Added new macro PySequence_ITEM(o, i) that directly calls
374 sq_item without rechecking that o is a sequence and without
375 adjusting for negative indices.
376
Fred Draked0ba6362002-05-02 21:28:26 +0000377- PyRange_New() now raises ValueError if the fourth argument is not 1.
378 This is part of the removal of deprecated features of the xrange
379 object.
380
Guido van Rossum517c7d42002-04-26 02:49:14 +0000381- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
382 coercion if both arguments have the same type but this type has the
383 CHECKTYPES flag set. This is to better support proxies.
384
Neil Schemenauer9344b142002-04-12 23:00:08 +0000385- The type of tp_free has been changed from "void (*)(PyObject *)" to
386 "void (*)(void *)".
387
388- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
389
Guido van Rossum0986d822002-04-08 01:38:42 +0000390- A type can now inherit its metatype from its base type. Previously,
391 when PyType_Ready() was called, if ob_type was found to be NULL, it
392 was always set to &PyType_Type; now it is set to base->ob_type,
393 where base is tp_base, defaulting to &PyObject_Type.
394
395- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
396
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000397- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000398
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000399- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000400 without going through the buffer API.
401
Martin v. Löwis7198a522002-01-01 19:59:11 +0000402- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
403
Tim Peters10a3bb52001-12-25 19:07:38 +0000404- An old #define of ANY as void has been removed from pyport.h. This
405 hasn't been used since Python's pre-ANSI days, and the #define has
406 been marked as obsolete since then. SF bug 495548 says it created
407 conflicts with other packages, so keeping it around wasn't harmless.
408
Tim Petersaf8446f2001-12-21 21:36:50 +0000409- Because Python's magic number scheme broke on January 1st, we decided
410 to stop Python development. Thanks for all the fish!
411
Tim Petersfb05db22002-03-11 00:24:00 +0000412- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000413 scheme to a new one. See Python/import.c for details.
414
Tim Petersaf8446f2001-12-21 21:36:50 +0000415New platforms
416
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000417- AtheOS is now supported.
418
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000419- GNU/Hurd is now supported.
420
Tim Petersaf8446f2001-12-21 21:36:50 +0000421Tests
422
423Windows
424
Tim Peters08e72952002-04-16 20:48:01 +0000425- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
426 of that has been fixed in the installer (disabled Wise's "delete in-
427 use files" uninstall option).
428
Guido van Rossum181e41a2002-04-06 00:23:25 +0000429- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
430
Tim Peters33187922002-04-04 20:02:04 +0000431- The installer now installs Start menu shortcuts under (the local
432 equivalent of) "All Users" when doing an Admin install.
433
Tim Petersfb05db22002-03-11 00:24:00 +0000434- file.truncate([newsize]) now works on Windows for all newsize values.
435 It used to fail if newsize didn't fit in 32 bits, reflecting a
436 limitation of MS _chsize (which is no longer used).
437
Tim Petersab034fa2002-02-01 11:27:43 +0000438- os.waitpid() is now implemented for Windows, and can be used to block
439 until a specified process exits. This is similar to, but not exactly
440 the same as, os.waitpid() on POSIX systems. If you're waiting for
441 a specific process whose pid was obtained from one of the spawn()
442 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000443 See the docs for details. The docs were changed to clarify that
444 spawn functions return, and waitpid requires, a process handle on
445 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000446
Tim Peters11bd9942002-02-01 00:52:29 +0000447- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000448 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000449 to a nasty problem: before 2.3, if you got a temp file on Windows, it
450 got wrapped in an object whose close() method first closed the
451 underlying file, then deleted the file. This usually worked fine.
452 However, the spawn family of functions on Windows create (at a low C
453 level) the same set of open files in the spawned process Q as were
454 open in the spawning process P. If a temp file f was among them, then
455 doing f.close() in P first closed P's C-level file handle on f, but Q's
456 C-level file handle on f remained open, so the attempt in P to delete f
457 blew up with a "Permission denied" error (Windows doesn't allow
458 deleting open files). This was surprising, subtle, and difficult to
459 work around.
460
461- The os module now exports all the symbolic constants usable with the
462 low-level os.open() on Windows: the new constants in 2.3 are
463 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
464 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
465 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
466 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
467 (so specify both if you want both; note that neither is useful unless
468 specified with O_CREAT too).
469
Tim Petersaf8446f2001-12-21 21:36:50 +0000470Mac
471
472
Tim Peters909c0912001-12-14 23:16:18 +0000473What's New in Python 2.2 final?
474Release date: 21-Dec-2001
475===============================
476
477Type/class unification and new-style classes
478
Barry Warsaw52acb492001-12-21 20:04:22 +0000479- pickle.py, cPickle: allow pickling instances of new-style classes
480 with a custom metaclass.
481
Tim Peters909c0912001-12-14 23:16:18 +0000482Core and builtins
483
Barry Warsaw52acb492001-12-21 20:04:22 +0000484- weakref proxy object: when comparing, unwrap both arguments if both
485 are proxies.
486
Tim Peters909c0912001-12-14 23:16:18 +0000487Extension modules
488
Barry Warsaw52acb492001-12-21 20:04:22 +0000489- binascii.b2a_base64(): fix a potential buffer overrun when encoding
490 very short strings.
491
492- cPickle: the obscure "fast" mode was suspected of causing stack
493 overflows on the Mac. Hopefully fixed this by setting the recursion
494 limit much smaller. If the limit is too low (it only affects
495 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
496 when compiling cPickle.c (or in pyconfig.h).
497
Tim Peters909c0912001-12-14 23:16:18 +0000498Library
499
Barry Warsaw52acb492001-12-21 20:04:22 +0000500- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
501 close or delete time).
502
503- rfc822.py: fixed a bug where the address '<>' was converted to None
504 instead of an empty string (also fixes the email.Utils module).
505
506- xmlrpclib.py: version 1.0.0; uses precision for doubles.
507
508- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000509 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000510
Tim Peters909c0912001-12-14 23:16:18 +0000511Tools/Demos
512
513Build
514
515C API
516
517New platforms
518
519Tests
520
521Windows
522
Barry Warsaw52acb492001-12-21 20:04:22 +0000523- distutils package: fixed broken Windows installers (bdist_wininst).
524
525- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
526 instances are deleted at process exit time.
527
528- socket.py: prevent mysterious warnings when socket instances are
529 deleted at process exit time.
530
531- posixmodule.c: fix a Windows crash with stat() of a filename ending
532 in backslash.
533
Tim Peters909c0912001-12-14 23:16:18 +0000534Mac
535
Barry Warsaw52acb492001-12-21 20:04:22 +0000536- The Carbon toolbox modules have been upgraded to Universal Headers
537 3.4, and experimental CoreGraphics and CarbonEvents modules have
538 been added. All only for framework-enabled MacOSX.
539
Tim Peters909c0912001-12-14 23:16:18 +0000540
Tim Peters6272dfd2001-12-13 19:34:00 +0000541What's New in Python 2.2c1?
542Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000543===========================
544
545Type/class unification and new-style classes
546
Barry Warsaw06557452001-12-14 20:47:12 +0000547- Guido's tutorial introduction to the new type/class features has
548 been extensively updated. See
549
550 http://www.python.org/2.2/descrintro.html
551
552 That remains the primary documentation in this area.
553
Guido van Rossum33bab012001-12-05 22:45:48 +0000554- Fixed a leak: instance variables declared with __slots__ were never
555 deleted!
556
Guido van Rossum4b800852001-12-03 00:54:52 +0000557- The "delete attribute" method of descriptor objects is called
558 __delete__, not __del__. In previous releases, it was mistakenly
559 called __del__, which created an unfortunate overloading condition
560 with finalizers. (The "get attribute" and "set attribute" methods
561 are still called __get__ and __set__, respectively.)
562
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000563- Some subtle issues with the super built-in were fixed:
564
565 (a) When super itself is subclassed, its __get__ method would still
566 return an instance of the base class (i.e., of super).
567
568 (b) super(C, C()).__class__ would return C rather than super. This
569 is confusing. To fix this, I decided to change the semantics of
570 super so that it only applies to code attributes, not to data
571 attributes. After all, overriding data attributes is not
572 supported anyway.
573
574 (c) The __get__ method didn't check whether the argument was an
575 instance of the type used in creation of the super instance.
576
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000577- Previously, hash() of an instance of a subclass of a mutable type
578 (list or dictionary) would return some value, rather than raising
579 TypeError. This has been fixed. Also, directly calling
580 dict.__hash__ and list.__hash__ now raises the same TypeError
581 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000582
Guido van Rossumd331cb52001-12-05 19:46:42 +0000583- New-style objects now support deleting their __dict__. This is for
584 all intents and purposes equivalent to assigning a brand new empty
585 dictionary, but saves space if the object is not used further.
586
Tim Petersb3c9af12001-11-17 00:21:57 +0000587Core and builtins
588
Tim Peters3caca232001-12-06 06:23:26 +0000589- -Qnew now works as documented in PEP 238: when -Qnew is passed on
590 the command line, all occurrences of "/" use true division instead
591 of classic division. See the PEP for details. Note that "all"
592 means all instances in library and 3rd-party modules, as well as in
593 your own code. As the PEP says, -Qnew is intended for use only in
594 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000595 Note that test_coercion.py in the standard Python test suite fails
596 under -Qnew; this is expected, and won't be repaired until true
597 division becomes the default (in the meantime, test_coercion is
598 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000599
Fred Drake6c01e252001-12-14 17:08:12 +0000600- complex() now only allows the first argument to be a string
601 argument, and raises TypeError if either the second arg is a string
602 or if the second arg is specified when the first is a string.
603
Tim Petersb3c9af12001-11-17 00:21:57 +0000604Extension modules
605
Martin v. Löwis560da622001-11-24 09:24:51 +0000606- gc.get_referents was renamed to gc.get_referrers.
607
Tim Petersb3c9af12001-11-17 00:21:57 +0000608Library
609
Tim Peters25059d32001-12-07 20:35:43 +0000610- Functions in the os.spawn() family now release the global interpreter
611 lock around calling the platform spawn. They should always have done
612 this, but did not before 2.2c1. Multithreaded programs calling
613 an os.spawn function with P_WAIT will no longer block all Python threads
614 until the spawned program completes. It's possible that some programs
615 relies on blocking, although more likely by accident than by design.
616
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000617- webbrowser defaults to netscape.exe on OS/2 now.
618
Martin v. Löwis652e1912001-11-25 14:50:56 +0000619- Tix.ResizeHandle exposes detach_widget, hide, and show.
620
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000621- The charset alias windows_1252 has been added.
622
Barry Warsaw06557452001-12-14 20:47:12 +0000623- types.StringTypes is a tuple containing the defined string types;
624 usually this will be (str, unicode), but if Python was compiled
625 without Unicode support it will be just (str,).
626
627- The pulldom and minidom modules were synchronized to PyXML.
628
Tim Petersb3c9af12001-11-17 00:21:57 +0000629Tools/Demos
630
Barry Warsaw06557452001-12-14 20:47:12 +0000631- A new script called Tools/scripts/google.py was added, which fires
632 off a search on Google.
633
Tim Petersb3c9af12001-11-17 00:21:57 +0000634Build
635
Barry Warsaw06557452001-12-14 20:47:12 +0000636- Note that release builds of Python should arrange to define the
637 preprocessor symbol NDEBUG on the command line (or equivalent).
638 In the 2.2 pre-release series we tried to define this by magic in
639 Python.h instead, but it proved to cause problems for extension
640 authors. The Unix, Windows and Mac builds now all define NDEBUG in
641 release builds via cmdline (or equivalent) instead. Ports to
642 other platforms should do likewise.
643
Jack Jansen1999ef42001-12-06 21:47:20 +0000644- It is no longer necessary to use --with-suffix when building on a
645 case-insensitive file system (such as Mac OS X HFS+). In the build
646 directory an extension is used, but not in the installed python.
647
Tim Petersb3c9af12001-11-17 00:21:57 +0000648C API
649
Tim Petersf582b822001-12-11 18:51:08 +0000650- New function PyDict_MergeFromSeq2() exposes the builtin dict
651 constructor's logic for updating a dictionary from an iterable object
652 producing key-value pairs.
653
Tim Peterscffed4b2001-11-29 03:26:37 +0000654- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000655 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000656 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
657 dump core in some bad cases. This has been repaired. As a result,
658 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
659 previously went unchallenged.
660
Tim Petersb3c9af12001-11-17 00:21:57 +0000661New platforms
662
663Tests
664
665Windows
666
667Mac
668
Jack Jansenffa260f2001-12-06 21:14:00 +0000669- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
670 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000671
Barry Warsaw06557452001-12-14 20:47:12 +0000672- Changed logic for finding python home in Mac OS X framework Pythons.
673 Now sys.executable points to the executable again, in stead of to
674 the shared library. The latter is used only for locating the python
675 home.
676
677
Tim Peters84362bc2001-10-19 17:55:30 +0000678What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000679Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000680===========================
681
682Type/class unification and new-style classes
683
Guido van Rossum3d27df02001-11-15 20:27:54 +0000684- Multiple inheritance mixing new-style and classic classes in the
685 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000686
687 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000688 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000689
690 The MRO (method resolution order) for each base class is respected
691 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000692 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000693 This needs to be documented.
694
Tim Petersa427a2b2001-10-29 22:25:45 +0000695- The new builtin dictionary() constructor, and dictionary type, have
696 been renamed to dict. This reflects a decade of common usage.
697
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000698- dict() now accepts an iterable object producing 2-sequences. For
699 example, dict(d.items()) == d for any dictionary d. The argument,
700 and the elements of the argument, can be any iterable objects.
701
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000702- New-style classes can now have a __del__ method, which is called
703 when the instance is deleted (just like for classic classes).
704
Guido van Rossum12d955c2001-10-26 14:56:06 +0000705- Assignment to object.__dict__ is now possible, for objects that are
706 instances of new-style classes that have a __dict__ (unless the base
707 class forbids it).
708
Guido van Rossumc8e56452001-10-22 00:43:43 +0000709- Methods of built-in types now properly check for keyword arguments
710 (formerly these were silently ignored). The only built-in methods
711 that take keyword arguments are __call__, __init__ and __new__.
712
Guido van Rossum86443212001-10-27 22:28:54 +0000713- The socket function has been converted to a type; see below.
714
Tim Peters84362bc2001-10-19 17:55:30 +0000715Core and builtins
716
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000717- Assignment to __debug__ raises SyntaxError at compile-time. This
718 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000719 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000720
Guido van Rossum12d955c2001-10-26 14:56:06 +0000721- Clarified the error messages for unsupported operands to an operator
722 (like 1 + '').
723
Tim Peters84362bc2001-10-19 17:55:30 +0000724Extension modules
725
Tim Peters5ebfd362001-11-13 23:11:19 +0000726- mmap has a new keyword argument, "access", allowing a uniform way for
727 both Windows and Unix users to create read-only, write-through and
728 copy-on-write memory mappings. This was previously possible only on
729 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000730 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000731 platforms. Thanks to Jay T Miller for repairing this!
732
Tim Peters169ded02001-11-03 19:57:21 +0000733- By default, the gc.garbage list now contains only those instances in
734 unreachable cycles that have __del__ methods; in 2.1 it contained all
735 instances in unreachable cycles. "Instances" here has been generalized
736 to include instances of both new-style and old-style classes.
737
Guido van Rossum12d955c2001-10-26 14:56:06 +0000738- The socket module defines a new method for socket objects,
739 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000740 send() until all data has been sent. Also, the socket function has
741 been converted to a subclassable type, like list and tuple (etc.)
742 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000743
744- Various bugfixes to the curses module. There is now a test suite
745 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000746
Guido van Rossum692adf12001-10-30 03:03:03 +0000747- binascii.b2a_base64 no longer places an arbitrary restriction of 57
748 bytes on its input.
749
Tim Peters84362bc2001-10-19 17:55:30 +0000750Library
751
Tim Peters5ebfd362001-11-13 23:11:19 +0000752- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000753 convenience function.
754
Tim Peters75335872001-11-03 19:35:43 +0000755- Symbolic group names in regular expressions must be unique. For
756 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
757 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000758 Python 2.2 detects this error at regexp compilation time;
759 previously, the error went undetected, and results were
760 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
761 pattern.subn() methods have been rewritten in C. Also, an
762 experimental function/method finditer() has been added, which works
763 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000764
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000765- Tix exposes more commands through the classes DirSelectBox,
766 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
767 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
768 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
769
Tim Peters98791af2001-10-23 01:59:54 +0000770- Traceback objects are now scanned by cyclic garbage collection, so
771 cycles created by casual use of sys.exc_info() no longer cause
772 permanent memory leaks (provided garbage collection is enabled).
773
Guido van Rossum49192142001-10-24 20:51:44 +0000774- os.extsep -- a new variable needed by the RISCOS support. It is the
775 separator used by extensions, and is '.' on all platforms except
776 RISCOS, where it is '/'. There is no need to use this variable
777 unless you have a masochistic desire to port your code to RISCOS.
778
Barry Warsaw012852b2001-11-16 16:17:27 +0000779- mimetypes.py has optional support for non-standard, but commonly
780 found types. guess_type() and guess_extension() now accept an
781 optional `strict' flag, defaulting to true, which controls whether
782 recognize non-standard types or not. A few non-standard types we
783 know about have been added. Also, when run as a script, there are
784 new -l and -e options.
785
786- statcache is now deprecated.
787
788- email.Utils.formatdate() now produces the preferred RFC 2822 style
789 dates with numeric timezones (it used to produce obsolete dates
790 hard coded to "GMT" timezone). An optional `localtime' flag is
791 added to produce dates in the local timezone, with daylight savings
792 time properly taken into account.
793
794- In pickle and cPickle, instead of masking errors in load() by
795 transforming them into SystemError, we let the original exception
796 propagate out. Also, implement support for __safe_for_unpickling__
797 in pickle, as it already was supported in cPickle.
798
Tim Peters84362bc2001-10-19 17:55:30 +0000799Tools/Demos
800
801Build
802
Barry Warsaw012852b2001-11-16 16:17:27 +0000803- The dbm module is built using libdb1 if available. The bsddb module
804 is built with libdb3 if available.
805
806- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
807
Tim Peters84362bc2001-10-19 17:55:30 +0000808C API
809
Tim Peters1fc240e2001-10-26 05:06:50 +0000810- New function PySequence_Fast_GET_SIZE() returns the size of a non-
811 NULL result from PySequence_Fast(), more quickly than calling
812 PySequence_Size().
813
Barry Warsaw012852b2001-11-16 16:17:27 +0000814- New argument unpacking function PyArg_UnpackTuple() added.
815
816- New functions PyObject_CallFunctionObjArgs() and
817 PyObject_CallMethodObjArgs() have been added to make it more
818 convenient and efficient to call functions and methods from C.
819
820- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
821 possible that this will propagate errors it didn't before.
822
823- New function PyObject_CheckReadBuffer(), which returns true if its
824 argument supports the single-segment readable buffer interface.
825
Tim Peters84362bc2001-10-19 17:55:30 +0000826New platforms
827
Guido van Rossum86443212001-10-27 22:28:54 +0000828- We've finally confirmed that this release builds on HP-UX 11.00,
829 *with* threads, and passes the test suite.
830
Tim Peters7a33d8b2001-11-05 02:51:07 +0000831- Thanks to a series of patches from Michael Muller, Python may build
832 again under OS/2 Visual Age C++.
833
Guido van Rossum49192142001-10-24 20:51:44 +0000834- Updated RISCOS port by Dietmar Schwertberger.
835
Tim Peters84362bc2001-10-19 17:55:30 +0000836Tests
837
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000838- Added a test script for the curses module. It isn't run automatically;
839 regrtest.py must be run with '-u curses' to enable it.
840
Tim Peters84362bc2001-10-19 17:55:30 +0000841Windows
842
Barry Warsaw012852b2001-11-16 16:17:27 +0000843Mac
844
845- PythonScript has been moved to unsupported and is slated to be
846 removed completely in the next release.
847
848- It should now be possible to build applets that work on both OS9 and
849 OSX.
850
851- The core is now linked with CoreServices not Carbon; as a side
852 result, default 8bit encoding on OSX is now ASCII.
853
854- Python should now build on OSX 10.1.1
855
Tim Peters84362bc2001-10-19 17:55:30 +0000856
Tim Petersabf925f2001-09-28 21:53:42 +0000857What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000858Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000859===========================
860
861Type/class unification and new-style classes
862
Guido van Rossum687ae002001-10-15 22:03:32 +0000863- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000864 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000865 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000866 remains: the __dict__ of a new-style class is a read-only proxy; you
867 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000868 __defined__ attribute of new-style types no longer exists, for lack
869 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000870 future a __cache__ may be resurrected with a similar function, if I
871 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000872
Tim Peters1c9ca872001-10-04 06:43:12 +0000873- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
874 always returned None, even when there was a class docstring).
875
876- doctest now finds and runs docstrings attached to new-style classes,
877 class methods, static methods, and properties.
878
Guido van Rossum9074ef62001-10-16 21:34:49 +0000879Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000880
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000881- A very subtle syntactical pitfall in list comprehensions was fixed.
882 For example: [a+b for a in 'abc', for b in 'def']. The comma in
883 this example is a mistake. Previously, this would silently let 'a'
884 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
885 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
886 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
887 Note that [a for a in <singleton>] is a convoluted way to say
888 [<singleton>] anyway, so it's not like any expressiveness is lost.
889
Guido van Rossum9074ef62001-10-16 21:34:49 +0000890- getattr(obj, name, default) now only catches AttributeError, as
891 documented, rather than returning the default value for all
892 exceptions (which could mask bugs in a __getattr__ hook, for
893 example).
894
Fred Drakecb7a6b52001-10-22 18:41:51 +0000895- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000896 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000897 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000898 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000899
Guido van Rossum1c486092001-10-19 02:05:35 +0000900- unicode(obj) now behaves more like str(obj), accepting arbitrary
901 objects, and calling a __unicode__ method if it exists.
902 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000903 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000904
Barry Warsawf6fb1712001-10-19 05:35:40 +0000905- isinstance() now allows any object as the first argument and a
906 class, a type or something with a __bases__ tuple attribute for the
907 second argument. The second argument may also be a tuple of a
908 class, type, or something with __bases__, in which case isinstance()
909 will return true if the first argument is an instance of any of the
910 things contained in the second argument tuple. E.g.
911
912 isinstance(x, (A, B))
913
914 returns true if x is an instance of A or B.
915
Guido van Rossum9074ef62001-10-16 21:34:49 +0000916Extension modules
917
918- thread.start_new_thread() now returns the thread ID (previously None).
919
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000920- binascii has now two quopri support functions, a2b_qp and b2a_qp.
921
Guido van Rossumc524d952001-10-19 01:31:59 +0000922- readline now supports setting the startup_hook and the
923 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000924
Guido van Rossumc524d952001-10-19 01:31:59 +0000925- os and posix supports chroot(), setgroups() and unsetenv() where
926 available. The stat(), fstat(), statvfs() and fstatvfs() functions
927 now return "pseudo-sequences" -- the various fields can now be
928 accessed as attributes (e.g. os.stat("/").st_mtime) but for
929 backwards compatibility they also behave as a fixed-length sequence.
930 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000931 attributes.
932
933- time: localtime(), gmtime() and strptime() now return a
934 pseudo-sequence similar to the os.stat() return value, with
935 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000936
Guido van Rossum9074ef62001-10-16 21:34:49 +0000937- Decompression objects in the zlib module now accept an optional
938 second parameter to decompress() that specifies the maximum amount
939 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000940
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000941- optional SSL support in the socket module now exports OpenSSL
942 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
943 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000944 automatically seed its PRNG. Also, the keyfile and certfile
945 arguments to socket.ssl() are now optional.
946
947- posixmodule (and by extension, the os module on POSIX platforms) now
948 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000949
Guido van Rossum9074ef62001-10-16 21:34:49 +0000950Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000951
Tim Peters7402f792001-10-02 03:53:41 +0000952- doctest now excludes functions and classes not defined by the module
953 being tested, thanks to Tim Hochberg.
954
Fred Drakecb7a6b52001-10-22 18:41:51 +0000955- HotShot, a new profiler implemented using a C-based callback, has
956 been added. This substantially reduces the overhead of profiling,
957 but it is still quite preliminary. Support modules and
958 documentation will be added in upcoming releases (before 2.2 final).
959
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000960- profile now produces correct output in situations where an exception
961 raised in Python is cleared by C code (e.g. hasattr()). This used
962 to cause wrong output, including spurious claims of recursive
963 functions and attribution of time spent to the wrong function.
964
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000965 The code and documentation for the derived OldProfile and HotProfile
966 profiling classes was removed. The code hasn't worked for years (if
967 you tried to use them, they raised exceptions). OldProfile
968 intended to reproduce the behavior of the profiler Python used more
969 than 7 years ago, and isn't interesting anymore. HotProfile intended
970 to provide a faster profiler (but producing less information), and
971 that's a worthy goal we intend to meet via a different approach (but
972 without losing information).
973
Tim Peterscce092d2001-10-09 05:31:56 +0000974- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000975 a much better system-specific calibration constant. The constant can
976 now be specified in an instance constructor, or as a Profile class or
977 instance variable, instead of by editing profile.py's source code.
978 Calibration must still be done manually (see the docs for the profile
979 module).
980
981 Note that Profile.calibrate() must be overriden by subclasses.
982 Improving the accuracy required exploiting detailed knowledge of
983 profiler internals; the earlier method abstracted away the details
984 and measured a simplified model instead, but consequently computed
985 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000986
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000987- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000988 which indicates whether output is intended for the header 'Q'
989 encoding.
990
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000991- The SocketServer.ThreadingMixIn class now closes the request after
992 finish_request() returns. (Not when it errors out though.)
993
Barry Warsawf6fb1712001-10-19 05:35:40 +0000994- The nntplib module's NNTP.body() method has grown a `file' argument
995 to allow saving the message body to a file.
996
997- The email package has added a class email.Parser.HeaderParser which
998 only parses headers and does not recurse into the message's body.
999 Also, the module/class MIMEAudio has been added for representing
1000 audio data (contributed by Anthony Baxter).
1001
1002- ftplib should be able to handle files > 2GB.
1003
1004- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
1005 ON, and OFF.
1006
Fred Drakecb7a6b52001-10-22 18:41:51 +00001007- xml.dom.minidom NodeList objects now support the length attribute
1008 and item() method as required by the DOM specifications.
1009
Guido van Rossumed554f62001-10-02 23:15:37 +00001010Tools/Demos
1011
1012- Demo/dns was removed. It no longer serves any purpose; a package
1013 derived from it is now maintained by Anthony Baxter, see
1014 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +00001015
Barry Warsawf6fb1712001-10-19 05:35:40 +00001016- The freeze tool has been made more robust, and two new options have
1017 been added: -X and -E.
1018
Tim Petersabf925f2001-09-28 21:53:42 +00001019Build
1020
Barry Warsawf6fb1712001-10-19 05:35:40 +00001021- configure will use CXX in LINKCC if CXX is used to build main() and
1022 the system requires to link a C++ main using the C++ compiler.
1023
Tim Petersabf925f2001-09-28 21:53:42 +00001024C API
1025
Guido van Rossum6c4bce32001-10-18 19:20:25 +00001026- The documentation for the tp_compare slot is updated to require that
1027 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
1028 not correct. This is not yet enforced but will be enforced in
1029 Python 2.3; even later, we may use -2 to indicate errors and +2 for
1030 "NotImplemented". Right now, -1 should be used for an error return.
1031
Tim Petersd38b1c72001-09-30 05:09:37 +00001032- PyLong_AsLongLong() now accepts int (as well as long) arguments.
1033 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
1034 as long) arguments.
1035
Guido van Rossum3c288632001-10-16 21:13:49 +00001036- PyThread_start_new_thread() now returns a long int giving the thread
1037 ID, if one can be calculated; it returns -1 for error, 0 if no
1038 thread ID is calculated (this is an incompatible change, but only
1039 the thread module used this API). This code has only really been
1040 tested on Linux and Windows; other platforms please beware (and
1041 report any bugs or strange behavior).
1042
Guido van Rossum1c486092001-10-19 02:05:35 +00001043- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
1044 input.
1045
Tim Petersabf925f2001-09-28 21:53:42 +00001046New platforms
1047
1048Tests
1049
1050Windows
1051
Tim Peters04cf1d32001-10-09 22:39:40 +00001052- Installer: If you install IDLE, and don't disable file-extension
1053 registration, a new "Edit with IDLE" context (right-click) menu entry
1054 is created for .py and .pyw files.
1055
Tim Peters1ce3cf72001-10-01 17:58:40 +00001056- The signal module now supports SIGBREAK on Windows, thanks to Steven
1057 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
1058 action remains to call Win32 ExitProcess(). This can be changed via
1059 signal.signal(). For example:
1060
1061 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
1062 # (SIGINT) behavior.
1063 import signal
1064 signal.signal(signal.SIGBREAK,
1065 signal.default_int_handler)
1066
1067 try:
1068 while 1:
1069 pass
1070 except KeyboardInterrupt:
1071 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
1072 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
1073 # program without the possibility for any Python-level cleanup).
1074 print "Clean exit"
1075
Tim Petersabf925f2001-09-28 21:53:42 +00001076
Tim Petersb07352e2001-09-08 01:25:47 +00001077What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001078Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +00001079===========================
1080
Guido van Rossum808eea72001-09-25 04:15:41 +00001081Type/class unification and new-style classes
1082
1083- pydoc and inspect are now aware of new-style classes;
1084 e.g. help(list) at the interactive prompt now shows proper
1085 documentation for all operations on list objects.
1086
1087- Applications using Jim Fulton's ExtensionClass module can now safely
1088 be used with Python 2.2. In particular, Zope 2.4.1 now works with
1089 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
1090 examples also work again. It is hoped that Gtk and Boost also work
1091 with 2.2a4 and beyond. (If you can confirm this, please write
1092 webmaster@python.org; if there are still problems, please open a bug
1093 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +00001094
Tim Peters66c1a522001-09-24 21:17:50 +00001095- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001096 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001097 in the constructed property object. fget, fset and fdel weren't
1098 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1099 associate a docstring with a property.
1100
Guido van Rossum808eea72001-09-25 04:15:41 +00001101- Comparison overloading is now more completely implemented. For
1102 example, a str subclass instance can properly be compared to a str
1103 instance, and it can properly overload comparison. Ditto for most
1104 other built-in object types.
1105
1106- The repr() of new-style classes has changed; instead of <type
1107 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1108 *except* for built-in types, which are still rendered as <type
1109 'Foo'> (to avoid upsetting existing code that might parse or
1110 otherwise rely on repr() of certain type objects).
1111
1112- The repr() of new-style objects is now always <Foo object at XXX>;
1113 previously, it was sometimes <Foo instance at XXX>.
1114
1115- For new-style classes, what was previously called __getattr__ is now
1116 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001117 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001118 one in classic classes is defined which is called only if regular
1119 attribute access raises AttributeError; to catch *all* attribute
1120 access, you can use __getattribute__ (for new-style classes). If
1121 both are defined, __getattribute__ is called first, and if it raises
1122 AttributeError, __getattr__ is called.
1123
1124- The __class__ attribute of new-style objects can be assigned to.
1125 The new class must have the same C-level object layout as the old
1126 class.
1127
1128- The builtin file type can be subclassed now. In the usual pattern,
1129 "file" is the name of the builtin type, and file() is a new builtin
1130 constructor, with the same signature as the builtin open() function.
1131 file() is now the preferred way to open a file.
1132
1133- Previously, __new__ would only see sequential arguments passed to
1134 the type in a constructor call; __init__ would see both sequential
1135 and keyword arguments. This made no sense whatsoever any more, so
1136 now both __new__ and __init__ see all arguments.
1137
1138- Previously, hash() applied to an instance of a subclass of str or
1139 unicode always returned 0. This has been repaired.
1140
1141- Previously, an operation on an instance of a subclass of an
1142 immutable type (int, long, float, complex, tuple, str, unicode),
1143 where the subtype didn't override the operation (and so the
1144 operation was handled by the builtin type), could return that
1145 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001146 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001147 with the same value as s.
1148
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001149- Provisional support for pickling new-style objects has been added.
1150
Guido van Rossum808eea72001-09-25 04:15:41 +00001151Core
1152
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001153- file.writelines() now accepts any iterable object producing strings.
1154
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001155- PyUnicode_FromEncodedObject() now works very much like
1156 PyObject_Str(obj) in that it tries to use __str__/tp_str
1157 on the object if the object is not a string or buffer. This
1158 makes unicode() behave like str() when applied to non-string/buffer
1159 objects.
1160
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001161- PyFile_WriteObject now passes Unicode objects to the file's write
1162 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001163 of a print statement must support Unicode objects, i.e. they must
1164 at least convert them into ASCII strings.
1165
Guido van Rossum624c8af2001-09-18 15:21:04 +00001166- Thread scheduling on Solaris should be improved; it is no longer
1167 necessary to insert a small sleep at the start of a thread in order
1168 to let other runnable threads be scheduled.
1169
Tim Petersb07352e2001-09-08 01:25:47 +00001170Library
1171
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001172- StringIO.StringIO instances and cStringIO.StringIO instances support
1173 read character buffer compatible objects for their .write() methods.
1174 These objects are converted to strings and then handled as such
1175 by the instances.
1176
Barry Warsaw2f600732001-09-24 04:28:10 +00001177- The "email" package has been added. This is basically a port of the
1178 mimelib package <http://sf.net/projects/mimelib> with API changes
1179 and some implementations updated to use iterators and generators.
1180
Tim Peters8a9c2842001-09-22 21:30:22 +00001181- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1182 restores the ability of Tools/scripts/ndiff.py to start producing output
1183 before the entire comparison is complete.
1184
Barry Warsaw58b072d2001-09-22 04:44:21 +00001185- StringIO.StringIO instances and cStringIO.StringIO instances support
1186 iteration just like file objects (i.e. their .readline() method is
1187 called for each iteration until it returns an empty string).
1188
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001189- The codecs module has grown four new helper APIs to access
1190 builtin codecs: getencoder(), getdecoder(), getreader(),
1191 getwriter().
1192
Guido van Rossum624c8af2001-09-18 15:21:04 +00001193- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1194 simplifies writing XML RPC servers.
1195
Barry Warsaw647d5e82001-09-28 17:01:02 +00001196- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001197 after interpretation of symbolic links. On non-Unix systems, this
1198 is an alias for os.path.abspath().
1199
Tim Peters16a77ad2001-09-08 04:00:12 +00001200- operator.indexOf() (PySequence_Index() in the C API) now works with any
1201 iterable object.
1202
Guido van Rossum624c8af2001-09-18 15:21:04 +00001203- smtplib now supports various authentication and security features of
1204 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001205
Guido van Rossum624c8af2001-09-18 15:21:04 +00001206- hmac: a new module implementing keyed hashing for message
1207 authentication.
1208
1209- mimetypes now recognizes more extensions and file types. At the
1210 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001211
Guido van Rossum624c8af2001-09-18 15:21:04 +00001212- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001213 Python 2.2 bytecode generation. It has also been promoted from a
1214 Tool to a standard library package. (Tools/compiler still exists as
1215 a sample driver.)
1216
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001217Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001218
Tim Petersb07352e2001-09-08 01:25:47 +00001219Build
1220
Guido van Rossum624c8af2001-09-18 15:21:04 +00001221- Large file support (LFS) is now automatic when the platform supports
1222 it; no more manual configuration tweaks are needed. On Linux, at
1223 least, it's possible to have a system whose C library supports large
1224 files but whose kernel doesn't; in this case, large file support is
1225 still enabled but doesn't do you any good unless you upgrade your
1226 kernel or share your Python executable with another system whose
1227 kernel has large file support.
1228
1229- The configure script now supplies plausible defaults in a
1230 cross-compilation environment. This doesn't mean that the supplied
1231 values are always correct, or that cross-compilation now works
1232 flawlessly -- but it's a first step (and it shuts up most of
1233 autoconf's warnings about AC_TRY_RUN).
1234
1235- The Unix build is now a bit less chatty, courtesy of the parser
1236 generator. The build is completely silent (except for errors) when
1237 using "make -s", thanks to a -q option to setup.py.
1238
Tim Petersb07352e2001-09-08 01:25:47 +00001239C API
1240
Guido van Rossum624c8af2001-09-18 15:21:04 +00001241- The "structmember" API now supports some new flag bits to deny read
1242 and/or write access to attributes in restricted execution mode.
1243
Tim Petersb07352e2001-09-08 01:25:47 +00001244New platforms
1245
Guido van Rossum624c8af2001-09-18 15:21:04 +00001246- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1247 (http://familiar.handhelds.org).
1248
Tim Petersb07352e2001-09-08 01:25:47 +00001249Tests
1250
Tim Peters8a9c2842001-09-22 21:30:22 +00001251- The "classic" standard tests, which work by comparing stdout to
1252 an expected-output file under Lib/test/output/, no longer stop at
1253 the first mismatch. Instead the test is run to completion, and a
1254 variant of ndiff-style comparison is used to report all differences.
1255 This is much easier to understand than the previous style of reporting.
1256
1257- The unittest-based standard tests now use regrtest's test_main()
1258 convention, instead of running as a side-effect of merely being
1259 imported. This allows these tests to be run in more natural and
1260 flexible ways as unittests, outside the regrtest framework.
1261
1262- regrtest.py is much better integrated with unittest and doctest now,
1263 especially in regard to reporting errors.
1264
Tim Petersb07352e2001-09-08 01:25:47 +00001265Windows
1266
Guido van Rossum624c8af2001-09-18 15:21:04 +00001267- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001268 that support it (NTFS under Windows 2000). See "What's New in
1269 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001270
Tim Petersb07352e2001-09-08 01:25:47 +00001271
Tim Petersedc99312001-08-22 21:36:50 +00001272What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001273Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001274===========================
1275
1276Core
1277
Tim Peters9fffa3e2001-09-04 05:14:19 +00001278- Conversion of long to float now raises OverflowError if the long is too
1279 big to represent as a C double.
1280
Tim Peters32f453e2001-09-03 08:35:41 +00001281- The 3-argument builtin pow() no longer allows a third non-None argument
1282 if either of the first two arguments is a float, or if both are of
1283 integer types and the second argument is negative (in which latter case
1284 the arguments are converted to float, so this is really the same
1285 restriction).
1286
Tim Peters5d2b77c2001-09-03 05:47:38 +00001287- The builtin dir() now returns more information, and sometimes much
1288 more, generally naming all attributes of an object, and all attributes
1289 reachable from the object via its class, and from its class's base
1290 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1291 an empty list. In 2.2a3,
1292
1293 >>> dir([])
1294 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1295 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1296 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1297 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1298 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1299 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1300 'reverse', 'sort']
1301
1302 dir(module) continues to return only the module's attributes, though.
1303
Tim Petersbdee63f2001-09-02 03:40:59 +00001304- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001305 than raising OverflowError. This is a partial implementation of PEP
1306 237. You can use -Wdefault::OverflowWarning to enable a warning for
1307 this situation, and -Werror::OverflowWarning to revert to the old
1308 OverflowError exception.
1309
Guido van Rossum61c345f2001-09-04 03:26:15 +00001310- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001311 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001312 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1313 -Qold, meaning the / operator has its classic meaning and no
1314 warnings are issued. Using -Qwarn issues a run-time warning about
1315 all uses of classic division for int and long arguments; -Qwarnall
1316 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001317 (for use with fixdiv.py).
1318 [Note: the remainder of this paragraph (preserved below) became
1319 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1320 <obsolete>
1321 Using -Qnew is questionable; it turns on new division by default, but
1322 only in the __main__ module. You can usefully combine -Qwarn or
1323 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1324 warns about classic division everywhere else.
1325 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001326
Tim Petersbdee63f2001-09-02 03:40:59 +00001327- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001328 long, float, str, unicode, and tuple. (The types complex, list and
1329 dictionary can also be subclassed; this was introduced earlier.)
1330 Note that restrictions apply when subclassing immutable built-in
1331 types: you can only affect the value of the instance by overloading
1332 __new__. You can add mutable attributes, and the subclass instances
1333 will have a __dict__ attribute, but you cannot change the "value"
1334 (as implemented by the base class) of an immutable subclass instance
1335 once it is created.
1336
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001337- The dictionary constructor now takes an optional argument, a
1338 mapping-like object, and initializes the dictionary from its
1339 (key, value) pairs.
1340
Tim Petersbdee63f2001-09-02 03:40:59 +00001341- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001342 "cooperative super calls" in a multiple inheritance setting. For an
1343 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1344
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001345- A new built-in type, property, has been added. This enables the
1346 creation of "properties". These are attributes implemented by
1347 getter and setter functions (or only one of these for read-only or
1348 write-only attributes), without the need to override __getattr__.
1349 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001350
Tim Petersbdee63f2001-09-02 03:40:59 +00001351- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001352 liberalized, to allow leading zeroes. Examples of literals now
1353 legal that were SyntaxErrors before:
1354
1355 00.0 0e3 0100j 07.5 00000000000000000008.
1356
Tim Petersbdee63f2001-09-02 03:40:59 +00001357- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001358 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1359
Tim Petersedc99312001-08-22 21:36:50 +00001360Library
1361
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001362- telnetlib includes symbolic names for the options, and support for
1363 setting an option negotiation callback.
1364
Tim Petersa40c7932001-09-05 22:36:56 +00001365- The new C standard no longer requires that math libraries set errno to
1366 ERANGE on overflow. For platform libraries that exploit this new
1367 freedom, Python's overflow-checking was wholly broken. A new overflow-
1368 checking scheme attempts to repair that, but may not be reliable on all
1369 platforms (C doesn't seem to provide anything both useful and portable
1370 in this area anymore).
1371
Martin v. Löwis44f86962001-09-05 13:44:54 +00001372- Asynchronous timeout actions are available through the new class
1373 threading.Timer.
1374
Tim Peters78526162001-09-05 00:53:45 +00001375- math.log and math.log10 now return sensible results for even huge
1376 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1377
Tim Petersbdee63f2001-09-02 03:40:59 +00001378- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001379 currently held. See the docs for the imp module.
1380
Tim Petersbdee63f2001-09-02 03:40:59 +00001381- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001382 dumps containing ints written on platforms where Python ints are 8 bytes.
1383 When read on a box where Python ints are 4 bytes, such values are
1384 converted to Python longs.
1385
Tim Petersbdee63f2001-09-02 03:40:59 +00001386- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001387 code objects is no longer allowed. This plugs a security hole.
1388
Steve Purcell6091cd62001-09-06 16:05:17 +00001389- unittest.TestResult instances no longer store references to tracebacks
1390 generated by test failures. This prevents unexpected dangling references
1391 to objects that should be garbage collected between tests.
1392
Tim Petersedc99312001-08-22 21:36:50 +00001393Tools
1394
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001395- Tools/scripts/fixdiv.py has been added which can be used to fix
1396 division operators as per PEP 238.
1397
Tim Petersedc99312001-08-22 21:36:50 +00001398Build
1399
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001400- If you are an adventurous person using Mac OS X you may want to look at
1401 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1402 application, which can be used for experimenting with Carbon or Cocoa.
1403 Discussion of this on pythonmac-sig, please.
1404
Tim Peters7eea37e2001-09-04 22:08:56 +00001405C API
1406
1407- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001408
Tim Peters9fffa3e2001-09-04 05:14:19 +00001409- Note that PyLong_AsDouble can fail! This has always been true, but no
1410 callers checked for it. It's more likely to fail now, because overflow
1411 errors are properly detected now. The proper way to check:
1412
1413 double x = PyLong_AsDouble(some_long_object);
1414 if (x == -1.0 && PyErr_Occurred()) {
1415 /* The conversion failed. */
1416 }
1417
Tim Petersbdee63f2001-09-02 03:40:59 +00001418- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001419 compile but will not participate in GC. To upgrade an extension
1420 module:
1421
1422 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001423
Neil Schemenauer4042c692001-08-30 15:38:01 +00001424 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1425 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001426
Neil Schemenauer4042c692001-08-30 15:38:01 +00001427 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1428 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001429
Neil Schemenauer4042c692001-08-30 15:38:01 +00001430 - remove PyGC_HEAD_SIZE from object size calculations
1431
1432 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1433
Tim Petersbdee63f2001-09-02 03:40:59 +00001434- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001435 These can be used safely to construct string objects from a
1436 sprintf-style format string (similar to the format string supported
1437 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001438
Tim Petersedc99312001-08-22 21:36:50 +00001439New platforms
1440
Tim Petersb7da0902001-09-02 23:01:43 +00001441- Stephen Hansen contributed patches sufficient to get a clean compile
1442 under Borland C (Windows), but he reports problems running it and ran
1443 out of time to complete the port. Volunteers? Expect a MemoryError
1444 when importing the types module; this is probably shallow, and
1445 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001446
Tim Petersedc99312001-08-22 21:36:50 +00001447Tests
1448
1449Windows
1450
Tim Peters6e13a562001-09-06 00:32:15 +00001451- Large file support is now enabled on Win32 platforms as well as on
1452 Win64. This means that, for example, you can use f.tell() and f.seek()
1453 to manipulate files larger than 2 gigabytes (provided you have enough
1454 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001455 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1456 filesize limit, and large file support makes no difference there.
1457 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1458 NTFS has no practical limit on file size, and files of any size can be
1459 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001460
Tim Petersbdee63f2001-09-02 03:40:59 +00001461- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001462 points to command.com (patch from Brian Quinlan).
1463
Tim Petersedc99312001-08-22 21:36:50 +00001464
Tim Peters20f51a72001-07-21 02:31:40 +00001465What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001466Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001467===========================
1468
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001469Build
1470
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001471- Tim Peters developed a brand new Windows installer using Wise 8.1,
1472 generously donated to us by Wise Solutions.
1473
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001474- configure supports a new option --enable-unicode, with the values
1475 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1476 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001477
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001478- A new configure option --enable-framework builds a Mac OS X framework,
1479 which "make frameworkinstall" will install. This provides a starting
1480 point for more mac-like functionality, join pythonmac-sig@python.org
1481 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001482
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001483- The NeXT platform is no longer supported.
1484
1485- The `new' module is now statically linked.
1486
Tim Peters0afb6092001-08-15 06:06:44 +00001487Tools
1488
1489- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001490 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001491 the module docstring for details.
1492
Tim Peters20f51a72001-07-21 02:31:40 +00001493Tests
1494
Tim Peters5e824c32001-08-12 22:25:01 +00001495- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001496 platforms, allowing to give clearer test result output. regrtest
1497 also has optional --use/-u switch to run normally disabled tests
1498 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001499
Tim Peters20f51a72001-07-21 02:31:40 +00001500- Several new tests in the standard test suite, with special thanks to
1501 Nick Mathewson.
1502
1503Core
1504
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001505- The floor division operator // has been added as outlined in PEP
1506 238. The / operator still provides classic division (and will until
1507 Python 3.0) unless "from __future__ import division" is included, in
1508 which case the / operator will provide true division. The operator
1509 module provides truediv() and floordiv() functions. Augmented
1510 assignment variants are included, as are the equivalent overloadable
1511 methods and C API methods. See the PEP for a full discussion:
1512 <http://python.sf.net/peps/pep-0238.html>
1513
Tim Peters6cd6a822001-08-17 22:11:27 +00001514- Future statements are now effective in simulated interactive shells
1515 (like IDLE). This should "just work" by magic, but read Michael
1516 Hudson's "Future statements in simulated shells" PEP 264 for full
1517 details: <http://python.sf.net/peps/pep-0264.html>.
1518
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001519- The type/class unification (PEP 252-253) was integrated into the
1520 trunk and is not so tentative any more (the exact specification of
1521 some features is still tentative). A lot of work has done on fixing
1522 bugs and adding robustness and features (performance still has to
1523 come a long way).
1524
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001525- Warnings about a mismatch in the Python API during extension import
1526 now use the Python warning framework (which makes it possible to
1527 write filters for these warnings).
1528
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001529- A function's __dict__ (aka func_dict) will now always be a
1530 dictionary. It used to be possible to delete it or set it to None,
1531 but now both actions raise TypeErrors. It is still legal to set it
1532 to a dictionary object. Getting func.__dict__ before any attributes
1533 have been assigned now returns an empty dictionary instead of None.
1534
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001535- A new command line option, -E, was added which disables the use of
1536 all environment variables, or at least those that are specifically
1537 significant to Python. Usually those have a name starting with
1538 "PYTHON". This was used to fix a problem where the tests fail if
1539 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1540 older distribution.
1541
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001542Library
1543
Tim Peters5e824c32001-08-12 22:25:01 +00001544- New class Differ and new functions ndiff() and restore() in difflib.py.
1545 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001546 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001547
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001548- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1549 value using the minimal quoting required for the value; more
1550 reliable than using xml.sax.saxutils.escape() for attribute values.
1551
1552- Readline completion support for cmd.Cmd was added.
1553
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001554- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1555
1556- Added function threading.BoundedSemaphore()
1557
1558- Added Ka-Ping Yee's cgitb.py module.
1559
1560- The `new' module now exposes the CO_xxx flags.
1561
Martin v. Löwis560da622001-11-24 09:24:51 +00001562- The gc module offers the get_referents function.
1563
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001564New platforms
1565
1566C API
1567
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001568- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1569 which provide a cross-platform implementations for the
1570 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1571 the standard sprintf() and vsprintf() C lib APIs, these versions
1572 apply bounds checking on the used buffer which enhances protection
1573 against buffer overruns.
1574
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001575- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001576 and extensions using different Unicode widths is rendered next to
1577 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001578 will result in an ImportError. Unicode extensions writers must make
1579 sure to check the Unicode width compatibility in their extensions by
1580 using at least one of the mangled Unicode APIs in the extension.
1581
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001582- Two new flags METH_NOARGS and METH_O are available in method definition
1583 tables to simplify implementation of methods with no arguments and a
1584 single untyped argument. Calling such methods is more efficient than
1585 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1586 deprecated.
1587
Tim Petersc1731372001-08-04 08:12:36 +00001588Windows
1589
1590- "import module" now compiles module.pyw if it exists and nothing else
1591 relevant is found.
1592
Tim Peters20f51a72001-07-21 02:31:40 +00001593
Guido van Rossum55a78992001-07-17 17:22:32 +00001594What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001595Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001596===========================
1597
1598Core
Tim Petersa814db52001-05-14 07:05:58 +00001599
Tim Peters6d6c1a32001-08-02 04:15:00 +00001600- TENTATIVELY, a large amount of code implementing much of what's
1601 described in PEP 252 (Making Types Look More Like Classes) and PEP
1602 253 (Subtyping Built-in Types) was added. This will be released
1603 with Python 2.2a1. Documentation will be provided separately
1604 through http://www.python.org/2.2/. The purpose of releasing this
1605 with Python 2.2a1 is to test backwards compatibility. It is
1606 possible, though not likely, that a decision is made not to release
1607 this code as part of 2.2 final, if any serious backwards
1608 incompapatibilities are found during alpha testing that cannot be
1609 repaired.
1610
Guido van Rossum55a78992001-07-17 17:22:32 +00001611- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001612 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001613 more 'yield' statements. See PEP 255. Since this adds a new
1614 keyword to the language, this feature must be enabled by including a
1615 future statement: "from __future__ import generators" (see PEP 236).
1616 Generators will become a standard feature in a future release
1617 (probably 2.3). Without this future statement, 'yield' remains an
1618 ordinary identifier, but a warning is issued each time it is used.
1619 (These warnings currently don't conform to the warnings framework of
1620 PEP 230; we intend to fix this in 2.2a2.)
1621
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001622- The UTF-16 codec was modified to be more RFC compliant. It will now
1623 only remove BOM characters at the start of the string and then
1624 only if running in native mode (UTF-16-LE and -BE won't remove a
1625 leading BMO character).
1626
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001627- Strings now have a new method .decode() to complement the already
1628 existing .encode() method. These two methods provide direct access
1629 to the corresponding decoders and encoders of the registered codecs.
1630
1631 To enhance the usability of the .encode() method, the special
1632 casing of Unicode object return values was dropped (Unicode objects
1633 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001634
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001635 Both methods will now return whatever the codec in charge of the
1636 requested encoding returns as object, e.g. Unicode codecs will
1637 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1638 will return u"äöü"). This enables codec writer to create codecs
1639 for various simple to use conversions.
1640
1641 New codecs were added to demonstrate these new features (the .encode()
1642 and .decode() columns indicate the type of the returned objects):
1643
1644 Name | .encode() | .decode() | Description
1645 ----------------------------------------------------------------------
1646 uu | string | string | UU codec (e.g. for email)
1647 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001648 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001649 zlib | string | string | zlib compression
1650 hex | string | string | 2-byte hex codec
1651 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1652
Mark Hammond2a0af792001-05-14 03:09:36 +00001653- Some operating systems now support the concept of a default Unicode
1654 encoding for file system operations. Notably, Windows supports 'mbcs'
1655 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001656 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001657 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001658
1659 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001660 functions that return filenames (such as os.listdir()) to return Python
1661 string objects pre-encoded using the default file system encoding for
1662 the platform. As this encoding is likely to be different from Python's
1663 default encoding, converting this name to a Unicode object before passing
1664 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001665 would attempt to use its default encoding (generally ASCII) rather than
1666 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001667
Tim Petersa814db52001-05-14 07:05:58 +00001668 In general, this change simply removes surprises when working with
1669 Unicode and the file system, making these operations work as you expect,
1670 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001671 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001672
Tim Peters61dff2b2001-05-08 15:43:37 +00001673- Float (and complex) literals in source code were evaluated to full
1674 precision only when running from a .py file; the same code loaded from a
1675 .pyc (or .pyo) file could suffer numeric differences starting at about the
1676 12th significant decimal digit. For example, on a machine with IEEE-754
1677 floating arithmetic,
1678
1679 x = 9007199254740992.0
1680 print long(x)
1681
1682 printed 9007199254740992 if run directly from .py, but 9007199254740000
1683 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1684 str(float) instead of repr(float) when building code objects. marshal
1685 now uses repr(float) instead, which should reproduce floats to full
1686 machine precision (assuming the platform C float<->string I/O conversion
1687 functions are of good quality).
1688
1689 This may cause floating-point results to change in some cases, and
1690 usually for the better, but may also cause numerically unstable
1691 algorithms to break.
1692
Tim Peters2f228e72001-05-13 00:19:31 +00001693- The implementation of dicts suffers fewer collisions, which has speed
1694 benefits. However, the order in which dict entries appear in dict.keys(),
1695 dict.values() and dict.items() may differ from previous releases for a
1696 given dict. Nothing is defined about this order, so no program should
1697 rely on it. Nevertheless, it's easy to write test cases that rely on the
1698 order by accident, typically because of printing the str() or repr() of a
1699 dict to an "expected results" file. See Lib/test/test_support.py's new
1700 sortdict(dict) function for a simple way to display a dict in sorted
1701 order.
1702
Tim Peters7a3bfc32001-06-12 01:22:22 +00001703- Many other small changes to dicts were made, resulting in faster
1704 operation along the most common code paths.
1705
Guido van Rossum10315822001-05-01 20:54:30 +00001706- Dictionary objects now support the "in" operator: "x in dict" means
1707 the same as dict.has_key(x).
1708
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001709- The update() method of dictionaries now accepts generic mapping
1710 objects. Specifically the argument object must support the .keys()
1711 and __getitem__() methods. This allows you to say, for example,
1712 {}.update(UserDict())
1713
Guido van Rossum10315822001-05-01 20:54:30 +00001714- Iterators were added; this is a generalized way of providing values
1715 to a for loop. See PEP 234. There's a new built-in function iter()
1716 to return an iterator. There's a new protocol to get the next value
1717 from an iterator using the next() method (in Python) or the
1718 tp_iternext slot (in C). There's a new protocol to get iterators
1719 using the __iter__() method (in Python) or the tp_iter slot (in C).
1720 Iterating (i.e. a for loop) over a dictionary generates its keys.
1721 Iterating over a file generates its lines.
1722
Tim Petersf553f892001-05-01 20:45:31 +00001723- The following functions were generalized to work nicely with iterator
1724 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001725 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001726 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1727 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001728 join() method of strings
1729 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001730 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1731 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001732 right-hand side of assignment statements with multiple targets, such as
1733 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001734
Tim Petersd85e1022001-05-11 21:51:48 +00001735- Accessing module attributes is significantly faster (for example,
1736 random.random or os.path or yourPythonModule.yourAttribute).
1737
Tim Peterse63415e2001-05-08 04:38:29 +00001738- Comparing dictionary objects via == and != is faster, and now works even
1739 if the keys and values don't support comparisons other than ==.
1740
Tim Peters95bf9392001-05-10 08:32:44 +00001741- Comparing dictionaries in ways other than == and != is slower: there were
1742 insecurities in the dict comparison implementation that could cause Python
1743 to crash if the element comparison routines for the dict keys and/or
1744 values mutated the dicts. Making the code bulletproof slowed it down.
1745
Tim Peterseb28ef22001-06-02 05:27:19 +00001746- Collisions in dicts are resolved via a new approach, which can help
1747 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001748 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001749 faster now. Thanks to Christian Tismer for pointing out the cause and
1750 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001751
Tim Peters52e155e2001-06-16 05:42:57 +00001752- repr() is much faster for large containers (dict, list, tuple).
1753
1754
Tim Petersa814db52001-05-14 07:05:58 +00001755Library
1756
Fred Drake960fdf92001-07-20 18:38:26 +00001757- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1758 were added to the string module. These a locale-indenpendent
1759 constants, unlike letters, lowercase, and uppercase. These are now
1760 use in appropriate locations in the standard library.
1761
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001762- The flags used in dlopen calls can now be configured using
1763 sys.setdlopenflags and queried using sys.getdlopenflags.
1764
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001765- Fredrik Lundh's xmlrpclib is now a standard library module. This
1766 provides full client-side XML-RPC support. In addition,
1767 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1768 one asyncore-based). Thanks to Eric Raymond for the documentation.
1769
Guido van Rossum643d3912001-07-05 14:46:25 +00001770- The xrange() object is simplified: it no longer supports slicing,
1771 repetition, comparisons, efficient 'in' checking, the tolist()
1772 method, or the start, stop and step attributes. See PEP 260.
1773
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001774- A new function fnmatch.filter to filter lists of file names was added.
1775
Barry Warsawffd674d2001-05-22 16:00:10 +00001776- calendar.py uses month and day names based on the current locale.
1777
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001778- strop is now *really* obsolete (this was announced before with 1.6),
1779 and issues DeprecationWarning when used (except for the four items
1780 that are still imported into string.py).
1781
Tim Petersa814db52001-05-14 07:05:58 +00001782- Cookie.py now sorts key+value pairs by key in output strings.
1783
1784- pprint.isrecursive(object) didn't correctly identify recursive objects.
1785 Now it does.
1786
Tim Peters95b3f782001-05-14 18:39:41 +00001787- pprint functions now much faster for large containers (tuple, list, dict).
1788
Tim Peters7b9542a2001-06-10 23:40:19 +00001789- New 'q' and 'Q' format codes in the struct module, corresponding to C
1790 types "long long" and "unsigned long long" (on Windows, __int64). In
1791 native mode, these can be used only when the platform C compiler supports
1792 these types (when HAVE_LONG_LONG is #define'd by the Python config
1793 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001794 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1795 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001796
Guido van Rossum83213cc2001-06-12 16:48:52 +00001797- The site module installs a new built-in function 'help' that invokes
1798 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1799 it displays a message reminding the user to use 'help()' or
1800 'help(object)'.
1801
Tim Petersa814db52001-05-14 07:05:58 +00001802Tests
1803
1804- New test_mutants.py runs dict comparisons where the key and value
1805 comparison operators mutute the dicts randomly during comparison. This
1806 rapidly causes Python to crash under earlier releases (not for the faint
1807 of heart: it can also cause Win9x to freeze or reboot!).
1808
1809- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001810 pprint.isreadable() return sensible results. Also verifies that simple
1811 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001812
Tim Peters4324aa32001-05-28 22:30:08 +00001813C API
1814
1815- Removed the unused last_is_sticky argument from the internal
1816 _PyTuple_Resize(). If this affects you, you were cheating.
1817
1818
Guido van Rossum55a78992001-07-17 17:22:32 +00001819======================================================================
1820
1821
Guido van Rossumffe13be2001-04-16 18:46:45 +00001822What's New in Python 2.1 (final)?
1823=================================
1824
1825We only changed a few things since the last release candidate, all in
1826Python library code:
1827
1828- A bug in the locale module was fixed that affected locales which
1829 define no grouping for numeric formatting.
1830
1831- A few bugs in the weakref module's implementations of weak
1832 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1833 and the test suite was updated to check for these bugs.
1834
1835- An old bug in the os.path.walk() function (introduced in Python
1836 2.0!) was fixed: a non-existent file would cause an exception
1837 instead of being ignored.
1838
1839- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1840 PyChecker.
1841
1842
Guido van Rossum5b08f132001-04-16 02:05:23 +00001843What's New in Python 2.1c2?
1844===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001845
Guido van Rossum5b08f132001-04-16 02:05:23 +00001846A flurry of small changes, and one showstopper fixed in the nick of
1847time made it necessary to release another release candidate. The list
1848here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001849
Guido van Rossum5b08f132001-04-16 02:05:23 +00001850Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001851
Guido van Rossum5b08f132001-04-16 02:05:23 +00001852- Tim discovered a nasty bug in the dictionary code, caused by
1853 PyDict_Next() calling dict_resize(), and the GC code's use of
1854 PyDict_Next() violating an assumption in dict_items(). This was
1855 fixed with considerable amounts of band-aid, but the net effect is a
1856 saner and more robust implementation.
1857
1858- Made a bunch of symbols static that were accidentally global.
1859
1860Build and Ports
1861
1862- The setup.py script didn't check for a new enough version of zlib
1863 (1.1.3 is needed). Now it does.
1864
1865- Changed "make clean" target to also remove shared libraries.
1866
1867- Added a more general warning about the SGI Irix optimizer to README.
1868
1869Library
1870
1871- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1872 omitted the slash between host and file.html.
1873
1874- The mailbox module's _Mailbox class contained a completely broken
1875 and undocumented seek() method. Ripped it out.
1876
1877- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1878 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1879
1880- Fixed a few last-minute bugs in unittest.
1881
1882Extensions
1883
1884- Reverted the patch to the OpenSSL code in socketmodule.c to support
1885 RAND_status() and the EGD, and the subsequent patch that tried to
1886 fix it for pre-0.9.5 versions; the problem with the patch is that on
1887 some systems it issues a warning whenever socket is imported, and
1888 that's unacceptable.
1889
1890Tests
1891
1892- Fixed the pickle tests to work with "import test.test_pickle".
1893
1894- Tweaked test_locale.py to actually run the test Windows.
1895
1896- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1897 not "wb" (which is not a valid mode at all).
1898
1899- Fix pstats browser crashes. Import readline if it exists to make
1900 the user interface nicer.
1901
1902- Add "import thread" to the top of test modules that import the
1903 threading module (test_asynchat and test_threadedtempfile). This
1904 prevents test failures caused by a broken threading module resulting
1905 from a previously caught failed import.
1906
1907- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1908 needed on some platforms (e.g. Solaris 8) when the tests are run
1909 twice in succession.
1910
1911- Skip rather than fail test_sunaudiodev if no audio device is found.
1912
1913
1914What's New in Python 2.1c1?
1915===========================
1916
1917This list was significantly updated when 2.1c2 was released; the 2.1c1
1918release didn't mention most changes that were actually part of 2.1c1:
1919
1920Legal
1921
1922- Copyright was assigned to the Python Software Foundation (PSF) and a
1923 PSF license (very similar to the CNRI license) was added.
1924
1925- The CNRI copyright notice was updated to include 2001.
1926
1927Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001928
Guido van Rossumc9932722001-04-12 02:31:27 +00001929- After a public outcry, assignment to __debug__ is no longer illegal;
1930 instead, a warning is issued. It will become illegal in 2.2.
1931
Guido van Rossum5b08f132001-04-16 02:05:23 +00001932- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1933 "%#x" now always prepends "0x", even if the value is zero.
1934
1935- Fixed some nits in the bytecode compiler.
1936
1937- Fixed core dumps when calling certain kinds of non-functions.
1938
1939- Fixed various core dumps caused by reference count bugs.
1940
1941Build and Ports
1942
1943- Use INSTALL_SCRIPT to install script files.
1944
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001945- New port: SCO Unixware 7, by Billy G. Allie.
1946
Guido van Rossum5b08f132001-04-16 02:05:23 +00001947- Updated RISCOS port.
1948
1949- Updated BeOS port and notes.
1950
1951- Various other porting problems resolved.
1952
1953Library
1954
1955- The TERMIOS and SOCKET modules are now truly obsolete and
1956 unnecessary. Their symbols are incorporated in the termios and
1957 socket modules.
1958
1959- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1960 better tests for pickling.
1961
1962- threading: make Condition.wait() robust against KeyboardInterrupt.
1963
1964- zipfile: add support to zipfile to support opening an archive
1965 represented by an open file rather than a file name. Fix bug where
1966 the archive was not properly closed. Fixed a bug in this bugfix
1967 where flush() was called for a read-only file.
1968
1969- imputil: added an uninstall() method to the ImportManager.
1970
1971- Canvas: fixed bugs in lower() and tkraise() methods.
1972
1973- SocketServer: API change (added overridable close_request() method)
1974 so that the TCP server can explicitly close the request.
1975
1976- pstats: Eric Raymond added a simple interactive statistics browser,
1977 invoked when the module is run as a script.
1978
1979- locale: fixed a problem in format().
1980
1981- webbrowser: made it work when the BROWSER environment variable has a
1982 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1983 KDE 2. Fixed some other nits.
1984
1985- unittest: changes to allow using a different exception than
1986 AssertionError, and added a few more function aliases. Some other
1987 small changes.
1988
1989- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1990
1991- asynchat: fixed a critical bug in asynchat that slipped through the
1992 2.1b2 release. Fixed another rare bug.
1993
1994- Fix some unqualified except: clauses (always a bad code example).
1995
1996XML
1997
1998- pyexpat: new API get_version_string().
1999
2000- Fixed some minidom bugs.
2001
2002Extensions
2003
2004- Fixed a core dump in _weakref. Removed the weakref.mapping()
2005 function (it adds nothing to the API).
2006
2007- Rationalized the use of header files in the readline module, to make
2008 it compile (albeit with some warnings) with the very recent readline
2009 4.2, without breaking for earlier versions.
2010
2011- Hopefully fixed a buffering problem in linuxaudiodev.
2012
2013- Attempted a fix to make the OpenSSL support in the socket module
2014 work again with pre-0.9.5 versions of OpenSSL.
2015
2016Tests
2017
2018- Added a test case for asynchat and asyncore.
2019
2020- Removed coupling between tests where one test failing could break
2021 another.
2022
2023Tools
2024
2025- Ping added an interactive help browser to pydoc, fixed some nits
2026 in the rest of the pydoc code, and added some features to his
2027 inspect module.
2028
2029- An updated python-mode.el version 4.1 which integrates Ken
2030 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
2031 much nicer in XEmacs and Emacs. When stepping through your program
2032 with pdb, in either the shell window or the *Python* window, the
2033 source file and line will be tracked by an arrow. Very cool!
2034
2035- IDLE: syntax warnings in interactive mode are changed into errors.
2036
2037- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00002038 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00002039
2040- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00002041
Barry Warsaw11e89c72001-04-11 20:37:57 +00002042
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002043What's New in Python 2.1 beta 2?
2044================================
2045
Guido van Rossum053ae352001-03-22 14:17:21 +00002046(Unlisted are many fixed bugs, more documentation, etc.)
2047
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002048Core language, builtins, and interpreter
2049
Guido van Rossum053ae352001-03-22 14:17:21 +00002050- The nested scopes work (enabled by "from __future__ import
2051 nested_scopes") is completed; in particular, the future now extends
2052 into code executed through exec, eval() and execfile(), and into the
2053 interactive interpreter.
2054
2055- When calling a base class method (e.g. BaseClass.__init__(self)),
2056 this is now allowed even if self is not strictly spoken a class
2057 instance (e.g. when using metaclasses or the Don Beaudry hook).
2058
2059- Slice objects are now comparable but not hashable; this prevents
2060 dict[:] from being accepted but meaningless.
2061
2062- Complex division is now calculated using less braindead algorithms.
2063 This doesn't change semantics except it's more likely to give useful
2064 results in extreme cases. Complex repr() now uses full precision
2065 like float repr().
2066
2067- sgmllib.py now calls handle_decl() for simple <!...> declarations.
2068
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002069- It is illegal to assign to the name __debug__, which is set when the
2070 interpreter starts. It is effectively a compile-time constant.
2071
2072- A warning will be issued if a global statement for a variable
2073 follows a use or assignment of that variable.
2074
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002075Standard library
2076
Guido van Rossum053ae352001-03-22 14:17:21 +00002077- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
2078 inspired by JUnit), is now part of the standard library. You now
2079 have a choice of two testing frameworks: unittest requires you to
2080 write testcases as separate code, doctest gathers them from
2081 docstrings. Both approaches have their advantages and
2082 disadvantages.
2083
2084- A new module Tix was added, which wraps the Tix extension library
2085 for Tk. With that module, it is not necessary to statically link
2086 Tix with _tkinter, since Tix will be loaded with Tcl's "package
2087 require" command. See Demo/tix/.
2088
2089- tzparse.py is now obsolete.
2090
2091- In gzip.py, the seek() and tell() methods are removed -- they were
2092 non-functional anyway, and it's better if callers can test for their
2093 existence with hasattr().
2094
2095Python/C API
2096
2097- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2098 that's already in the dictionary during a PyDict_Next() iteration.
2099 This used to fail occasionally when a dictionary resize operation
2100 could be triggered that would rehash all the keys. All other
2101 modifications to the dictionary are still off-limits during a
2102 PyDict_Next() iteration!
2103
2104- New extended APIs related to passing compiler variables around.
2105
2106- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2107 implement isinstance() and issubclass().
2108
2109- Py_BuildValue() now has a "D" conversion to create a Python complex
2110 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002111
Fred Drake4e262a92001-03-22 18:26:47 +00002112- Extensions types which support weak references must now set the
2113 field allocated for the weak reference machinery to NULL themselves;
2114 this is done to avoid the cost of checking each object for having a
2115 weakly referencable type in PyObject_INIT(), since most types are
2116 not weakly referencable.
2117
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002118- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2119 free variables and cell variables to and from the frame's f_locals.
2120
2121- Variants of several functions defined in pythonrun.h have been added
2122 to support the nested_scopes future statement. The variants all end
2123 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2124 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2125 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002126 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002127
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002128Distutils
2129
2130- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2131 into the release tree.
2132
Tim Peters0e57abf2001-05-02 07:39:38 +00002133- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002134 (an uninstaller, more customization of the installer's display)
2135
2136- from Jack Jansen: added Mac-specific code to generate a dialog for
2137 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002138 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002139 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002140
2141- added 'platforms' and 'keywords' to the set of metadata that can be
2142 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002143
2144- applied patches from Jason Tishler to make the compiler class work with
2145 Cygwin.
2146
2147
Tim Peters2fe289a2001-03-01 22:19:38 +00002148What's New in Python 2.1 beta 1?
2149================================
Tim Petersd66595f2001-02-04 03:09:53 +00002150
2151Core language, builtins, and interpreter
2152
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002153- Following an outcry from the community about the amount of code
2154 broken by the nested scopes feature introduced in 2.1a2, we decided
2155 to make this feature optional, and to wait until Python 2.2 (or at
2156 least 6 months) to make it standard. The option can be enabled on a
2157 per-module basis by adding "from __future__ import nested_scopes" at
2158 the beginning of a module (before any other statements, but after
2159 comments and an optional docstring). See PEP 236 (Back to the
2160 __future__) for a description of the __future__ statement. PEP 227
2161 (Statically Nested Scopes) has been updated to reflect this change,
2162 and to clarify the semantics in a number of endcases.
2163
2164- The nested scopes code, when enabled, has been hardened, and most
2165 bugs and memory leaks in it have been fixed.
2166
2167- Compile-time warnings are now generated for a number of conditions
2168 that will break or change in meaning when nested scopes are enabled:
2169
2170 - Using "from...import *" or "exec" without in-clause in a function
2171 scope that also defines a lambda or nested function with one or
2172 more free (non-local) variables. The presence of the import* or
2173 bare exec makes it impossible for the compiler to determine the
2174 exact set of local variables in the outer scope, which makes it
2175 impossible to determine the bindings for free variables in the
2176 inner scope. To avoid the warning about import *, change it into
2177 an import of explicitly name object, or move the import* statement
2178 to the global scope; to avoid the warning about bare exec, use
2179 exec...in... (a good idea anyway -- there's a possibility that
2180 bare exec will be deprecated in the future).
2181
2182 - Use of a global variable in a nested scope with the same name as a
2183 local variable in a surrounding scope. This will change in
2184 meaning with nested scopes: the name in the inner scope will
2185 reference the variable in the outer scope rather than the global
2186 of the same name. To avoid the warning, either rename the outer
2187 variable, or use a global statement in the inner function.
2188
Neil Schemenauera35c6882001-02-27 04:45:05 +00002189- An optional object allocator has been included. This allocator is
2190 optimized for Python objects and should be faster and use less memory
2191 than the standard system allocator. It is not enabled by default
2192 because of possible thread safety problems. The allocator is only
2193 protected by the Python interpreter lock and it is possible that some
2194 extension modules require a thread safe allocator. The object
2195 allocator can be enabled by providing the "--with-pymalloc" option to
2196 configure.
2197
Tim Petersd66595f2001-02-04 03:09:53 +00002198Standard library
2199
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002200- pyexpat now detects the expat version if expat.h defines it. A
2201 number of additional handlers are provided, which are only available
2202 since expat 1.95. In addition, the methods SetParamEntityParsing and
2203 GetInputContext of Parser objects are available with 1.95.x
2204 only. Parser objects now provide the ordered_attributes and
2205 specified_attributes attributes. A new module expat.model was added,
2206 which offers a number of additional constants if 1.95.x is used.
2207
2208- xml.dom offers the new functions registerDOMImplementation and
2209 getDOMImplementation.
2210
2211- xml.dom.minidom offers a toprettyxml method. A number of DOM
2212 conformance issues have been resolved. In particular, Element now
2213 has an hasAttributes method, and the handling of namespaces was
2214 improved.
2215
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002216- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2217 getting information about live Python code, and pydoc.py, a module
2218 for interactively converting docstrings to HTML or text.
2219 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002220 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002221 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2222 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002223
Tim Peters1eff7962001-03-01 02:31:33 +00002224- New library module difflib.py, primarily packaging the SequenceMatcher
2225 class at the heart of the popular ndiff.py file-comparison tool.
2226
2227- doctest.py (a framework for verifying Python code examples in docstrings)
2228 is now part of the std library.
2229
Tim Petersd66595f2001-02-04 03:09:53 +00002230Windows changes
2231
Guido van Rossume3955a82001-03-02 14:05:59 +00002232- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2233 small GUI that lets you browse the module docstrings using your
2234 default web browser.
2235
Tim Peters1eff7962001-03-01 02:31:33 +00002236- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2237 Platforms) is implemented. See
2238
2239 http://python.sourceforge.net/peps/pep-0235.html
2240
2241 for full details, especially the "Current Lower-Left Semantics" section.
2242 The new Windows import rules are simpler than before:
2243
2244 A. If the PYTHONCASEOK environment variable exists, same as
2245 before: silently accept the first case-insensitive match of any
2246 kind; raise ImportError if none found.
2247
2248 B. Else search sys.path for the first case-sensitive match; raise
2249 ImportError if none found.
2250
2251 The same rules have been implented on other platforms with case-
2252 insensitive but case-preserving filesystems too (including Cygwin, and
2253 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002254
Tim Peters25a9ce32001-02-19 07:06:36 +00002255- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2256 what it's supposed to do (and does do under NT and 2000) via direct
2257 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002258 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002259 all Win9x systems before.
2260
Tim Peters1eff7962001-03-01 02:31:33 +00002261- Build: Subproject _test (effectively) renamed to _testcapi.
2262
Tim Peters2fe289a2001-03-01 22:19:38 +00002263New platforms
2264
2265- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2266 Thanks to Steven Majewski!
2267
2268- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2269 Tishler!
2270
Guido van Rossum9089b272001-03-02 06:49:50 +00002271- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2272 Schwertberger! See RISCOS/README for more information -- it seems
2273 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002274 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002275
Tim Peters25a9ce32001-02-19 07:06:36 +00002276
Tim Petersd7b5e882001-01-25 03:36:26 +00002277What's New in Python 2.1 alpha 2?
2278=================================
Tim Peters40ead762001-01-27 05:35:26 +00002279
Tim Petersd7b5e882001-01-25 03:36:26 +00002280Core language, builtins, and interpreter
2281
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002282- Scopes nest. If a name is used in a function or class, but is not
2283 local, the definition in the nearest enclosing function scope will
2284 be used. One consequence of this change is that lambda statements
2285 could reference variables in the namespaces where the lambda is
2286 defined. In some unusual cases, this change will break code.
2287
2288 In all previous version of Python, names were resolved in exactly
2289 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002290 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002291 function A is defined within a function B, the names bound in B are
2292 not visible in A. The new rules make names bound in B visible in A,
2293 unless A contains a name binding that hides the binding in B.
2294
2295 Section 4.1 of the reference manual describes the new scoping rules
2296 in detail. The test script in Lib/test/test_scope.py demonstrates
2297 some of the effects of the change.
2298
2299 The new rules will cause existing code to break if it defines nested
2300 functions where an outer function has local variables with the same
2301 name as globals or builtins used by the inner function. Example:
2302
2303 def munge(str):
2304 def helper(x):
2305 return str(x)
2306 if type(str) != type(''):
2307 str = helper(str)
2308 return str.strip()
2309
2310 Under the old rules, the name str in helper() is bound to the
2311 builtin function str(). Under the new rules, it will be bound to
2312 the argument named str and an error will occur when helper() is
2313 called.
2314
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002315- The compiler will report a SyntaxError if "from ... import *" occurs
2316 in a function or class scope. The language reference has documented
2317 that this case is illegal, but the compiler never checked for it.
2318 The recent introduction of nested scope makes the meaning of this
2319 form of name binding ambiguous. In a future release, the compiler
2320 may allow this form when there is no possibility of ambiguity.
2321
Tim Peters40ead762001-01-27 05:35:26 +00002322- repr(string) is easier to read, now using hex escapes instead of octal,
2323 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2324
2325 >>> "\texample \r\n" + chr(0) + chr(255)
2326 '\texample \r\n\x00\xff' # in 2.1
2327 '\011example \015\012\000\377' # in 2.0
2328
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002329- Functions are now compared and hashed by identity, not by value, since
2330 the func_code attribute is writable.
2331
Fred Drakefb9d7122001-02-01 20:00:40 +00002332- Weak references (PEP 205) have been added. This involves a few
2333 changes in the core, an extension module (_weakref), and a Python
2334 module (weakref). The weakref module is the public interface. It
2335 includes support for "explicit" weak references, proxy objects, and
2336 mappings with weakly held values.
2337
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002338- A 'continue' statement can now appear in a try block within the body
2339 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002340 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002341
Tim Petersd7b5e882001-01-25 03:36:26 +00002342Standard library
2343
Barry Warsaw30dbd142001-01-31 22:14:01 +00002344- mailbox.py now has a new class, PortableUnixMailbox which is
2345 identical to UnixMailbox but uses a more portable scheme for
2346 determining From_ separators. Also, the constructors for all the
2347 classes in this module have a new optional `factory' argument, which
2348 is a callable used when new message classes must be instantiated by
2349 the next() method.
2350
Tim Petersd7b5e882001-01-25 03:36:26 +00002351- random.py is now self-contained, and offers all the functionality of
2352 the now-deprecated whrandom.py. See the docs for details. random.py
2353 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002354 and restoring the internal state of the generator; and jumpahead(n),
2355 for quickly forcing the internal state to be the same as if n calls to
2356 random() had been made. The latter is particularly useful for multi-
2357 threaded programs, creating one instance of the random.Random() class for
2358 each thread, then using .jumpahead() to force each instance to use a
2359 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002360
Tim Peters0de88fc2001-02-01 04:59:18 +00002361- random.py's seed() function is new. For bit-for-bit compatibility with
2362 prior releases, use the whseed function instead. The new seed function
2363 addresses two problems: (1) The old function couldn't produce more than
2364 about 2**24 distinct internal states; the new one about 2**45 (the best
2365 that can be done in the Wichmann-Hill generator). (2) The old function
2366 sometimes produced identical internal states when passed distinct
2367 integers, and there was no simple way to predict when that would happen;
2368 the new one guarantees to produce distinct internal states for all
2369 arguments in [0, 27814431486576L).
2370
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002371- The socket module now supports raw packets on Linux. The socket
2372 family is AF_PACKET.
2373
Tim Peters9ea17ac2001-02-02 05:57:15 +00002374- test_capi.py is a start at running tests of the Python C API. The tests
2375 are implemented by the new Modules/_testmodule.c.
2376
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002377- A new extension module, _symtable, provides provisional access to the
2378 internal symbol table used by the Python compiler. A higher-level
2379 interface will be added on top of _symtable in a future release.
2380
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002381- Removed the obsolete soundex module.
2382
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002383- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2384 the isSameNode method; NamedNodeMap the get method.
2385
2386- xml.sax.expatreader supports the lexical handler property; it
2387 generates comment, startCDATA, and endCDATA events.
2388
Tim Petersee826f82001-01-31 19:39:44 +00002389Windows changes
2390
2391- Build procedure: the zlib project is built in a different way that
2392 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002393 the zlib binary used. See PCbuild\readme.txt for details. Your old
2394 zlib-related directories can be deleted; you'll need to download fresh
2395 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002396
Tim Peters9ea17ac2001-02-02 05:57:15 +00002397- Build: New subproject _test for the benefit of test_capi.py (see above).
2398
Tim Petersb16c56f2001-02-02 21:24:51 +00002399- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2400 interface to some Python compiler internals).
2401
2402- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002403 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002404
Tim Petersa3a3a032000-11-30 05:22:44 +00002405What's New in Python 2.1 alpha 1?
2406=================================
2407
2408Core language, builtins, and interpreter
2409
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002410- There is a new Unicode companion to the PyObject_Str() API
2411 called PyObject_Unicode(). It behaves in the same way as the
2412 former, but assures that the returned value is an Unicode object
2413 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002414
Guido van Rossumf98eda02001-01-17 15:54:45 +00002415- The comparison operators support "rich comparison overloading" (PEP
2416 207). C extension types can provide a rich comparison function in
2417 the new tp_richcompare slot in the type object. The cmp() function
2418 and the C function PyObject_Compare() first try the new rich
2419 comparison operators before trying the old 3-way comparison. There
2420 is also a new C API PyObject_RichCompare() (which also falls back on
2421 the old 3-way comparison, but does not constrain the outcome of the
2422 rich comparison to a Boolean result).
2423
2424 The rich comparison function takes two objects (at least one of
2425 which is guaranteed to have the type that provided the function) and
2426 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2427 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2428 object, which may be NotImplemented (in which case the tp_compare
2429 slot function is used as a fallback, if defined).
2430
2431 Classes can overload individual comparison operators by defining one
2432 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002433 __ge__. There are no explicit "reflected argument" versions of
2434 these; instead, __lt__ and __gt__ are each other's reflection,
2435 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2436 reflection (similar at the C level). No other implications are
2437 made; in particular, Python does not assume that == is the Boolean
2438 inverse of !=, or that < is the Boolean inverse of >=. This makes
2439 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002440
2441 Classes or types that want to implement (in)equality tests but not
2442 the ordering operators (i.e. unordered types) should implement ==
2443 and !=, and raise an error for the ordering operators.
2444
Guido van Rossuma88479f2001-01-18 14:28:08 +00002445 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002446 Boolean; e.g. a matrix type might want to return a matrix of bits
2447 for A < B, giving elementwise comparisons. Such types should ensure
2448 that any interpretation of their value in a Boolean context raises
2449 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2450 at the C level) to always raise an exception.
2451
Guido van Rossuma88479f2001-01-18 14:28:08 +00002452- Complex numbers use rich comparisons to define == and != but raise
2453 an exception for <, <=, > and >=. Unfortunately, this also means
2454 that cmp() of two complex numbers raises an exception when the two
2455 numbers differ. Since it is not mathematically meaningful to compare
2456 complex numbers except for equality, I hope that this doesn't break
2457 too much code.
2458
Tim Peters3389f192001-02-18 08:48:49 +00002459- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002460 not defined by the language, other than that it's arbitrary but
2461 consistent (see the Reference Manual). An implementation detail changed
2462 in 2.1a1 such that None now compares less than any other object. Code
2463 relying on this new behavior (like code that relied on the previous
2464 behavior) does so at its own risk.
2465
Barry Warsaw573b5412001-01-15 20:43:18 +00002466- Functions and methods now support getting and setting arbitrarily
2467 named attributes (PEP 232). Functions have a new __dict__
2468 (a.k.a. func_dict) which hold the function attributes. Methods get
2469 and set attributes on their underlying im_func. It is a TypeError
2470 to set an attribute on a bound method.
2471
Guido van Rossum051e3352001-01-15 19:11:10 +00002472- The xrange() object implementation has been improved so that
2473 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2474 limitation that in this case len(xrange(sys.maxint)) can't be
2475 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2476 work fine as long as the index i doesn't actually reach 2**31.
2477 (Python uses regular ints for sequence and string indices; fixing
2478 that is much more work.)
2479
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002480- Two changes to from...import:
2481
Guido van Rossumba381232001-02-03 15:06:40 +00002482 1) "from M import X" now works even if (after loading module M)
2483 sys.modules['M'] is not a real module; it's basically a getattr()
2484 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002485
2486 2) "from M import *" now looks for M.__all__ to decide which names to
2487 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2488 filters out names starting with '_' as before. Whether or not
2489 __all__ exists, there's no restriction on the type of M.
2490
Guido van Rossumf61f1662001-01-10 20:13:55 +00002491- File objects have a new method, xreadlines(). This is the fastest
2492 way to iterate over all lines in a file:
2493
2494 for line in file.xreadlines():
2495 ...do something to line...
2496
2497 See the xreadlines module (mentioned below) for how to do this for
2498 other file-like objects.
2499
2500- Even if you don't use file.xreadlines(), you may expect a speedup on
2501 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002502 quite a bit in platform-specific ways: on systems (like Linux) that
2503 support flockfile(), getc_unlocked(), and funlockfile(), those are
2504 used by default. On systems (like Windows) without getc_unlocked(),
2505 a complicated (but still thread-safe) method using fgets() is used by
2506 default.
2507
Tim Petersd52269b2001-01-25 06:23:18 +00002508 You can force use of the fgets() method by #define'ing
2509 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002510 getc_unlocked()).
2511
Tim Petersd52269b2001-01-25 06:23:18 +00002512 You can force fgets() not to be used by #define'ing
2513 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002514 test_bufio.py fails -- and let us know if it does!).
2515
2516- In addition, the fileinput module, while still slower than the other
2517 methods on most platforms, has been sped up too, by using
2518 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002519
2520- Support for run-time warnings has been added, including a new
2521 command line option (-W) to specify the disposition of warnings.
2522 See the description of the warnings module below.
2523
2524- Extensive changes have been made to the coercion code. This mostly
2525 affects extension modules (which can now implement mixed-type
2526 numerical operators without having to use coercion), but
2527 occasionally, in boundary cases the coercion semantics have changed
2528 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002529 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002530 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002531 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002532
Guido van Rossumf98eda02001-01-17 15:54:45 +00002533- In connection with the coercion changes, a new built-in singleton
2534 object, NotImplemented is defined. This can be returned for
2535 operations that wish to indicate they are not implemented for a
2536 particular combination of arguments. From C, this is
2537 Py_NotImplemented.
2538
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002539- The interpreter accepts now bytecode files on the command line even
2540 if they do not have a .pyc or .pyo extension. On Linux, after executing
2541
Martin v. Löwise214baa2001-02-04 22:37:56 +00002542import imp,sys,string
2543magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2544reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2545open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002546
2547 any byte code file can be used as an executable (i.e. as an argument
2548 to execve(2)).
2549
Tim Peters9940b802000-12-01 07:59:35 +00002550- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002551 character. In 1.6 and earlier, they never produced a sign,
2552 and raised an error if the value of the long was too large
2553 to fit in a Python int. In 2.0, they produced a sign if and
2554 only if too large to fit in an int. This was inconsistent
2555 across platforms (because the size of an int varies across
2556 platforms), and inconsistent with hex() and oct(). Example:
2557
2558 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002559 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002560 'ffffffbe' # in 2.0 and before, on 32-bit machines
2561 >>> hex(-0x42L)
2562 '-0x42L' # in all versions of Python
2563
Tim Peters9940b802000-12-01 07:59:35 +00002564 The behavior of %d formats for negative Python longs remains
2565 the same as in 2.0 (although in 1.6 and before, they raised
2566 an error if the long didn't fit in a Python int).
2567
2568 %u formats don't make sense for Python longs, but are allowed
2569 and treated the same as %d in 2.1. In 2.0, a negative long
2570 formatted via %u produced a sign if and only if too large to
2571 fit in an int. In 1.6 and earlier, a negative long formatted
2572 via %u raised an error if it was too big to fit in an int.
2573
Guido van Rossum3661d392000-12-12 22:10:31 +00002574- Dictionary objects have an odd new method, popitem(). This removes
2575 an arbitrary item from the dictionary and returns it (in the form of
2576 a (key, value) pair). This can be useful for algorithms that use a
2577 dictionary as a bag of "to do" items and repeatedly need to pick one
2578 item. Such algorithms normally end up running in quadratic time;
2579 using popitem() they can usually be made to run in linear time.
2580
Tim Peters36cdad12000-12-29 02:06:45 +00002581Standard library
2582
Thomas Woutersfe385252001-01-19 23:16:56 +00002583- In the time module, the time argument to the functions strftime,
2584 localtime, gmtime, asctime and ctime is now optional, defaulting to
2585 the current time (in the local timezone).
2586
Guido van Rossumda91f222001-01-15 16:36:08 +00002587- The ftplib module now defaults to passive mode, which is deemed a
2588 more useful default given that clients are often inside firewalls
2589 these days. Note that this could break if ftplib is used to connect
2590 to a *server* that is inside a firewall, from outside; this is
2591 expected to be a very rare situation. To fix that, you can call
2592 ftp.set_pasv(0).
2593
Martin v. Löwis10a27872001-01-13 09:54:41 +00002594- The module site now treats .pth files not only for path configuration,
2595 but also supports extensions to the initialization code: Lines starting
2596 with import are executed.
2597
Guido van Rossumf61f1662001-01-10 20:13:55 +00002598- There's a new module, warnings, which implements a mechanism for
2599 issuing and filtering warnings. There are some new built-in
2600 exceptions that serve as warning categories, and a new command line
2601 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2602 turns warnings into errors). warnings.warn(message[, category])
2603 issues a warning message; this can also be called from C as
2604 PyErr_Warn(category, message).
2605
2606- A new module xreadlines was added. This exports a single factory
2607 function, xreadlines(). The intention is that this code is the
2608 absolutely fastest way to iterate over all lines in an open
2609 file(-like) object:
2610
2611 import xreadlines
2612 for line in xreadlines.xreadlines(file):
2613 ...do something to line...
2614
2615 This is equivalent to the previous the speed record holder using
2616 file.readlines(sizehint). Note that if file is a real file object
2617 (as opposed to a file-like object), this is equivalent:
2618
2619 for line in file.xreadlines():
2620 ...do something to line...
2621
Tim Peters36cdad12000-12-29 02:06:45 +00002622- The bisect module has new functions bisect_left, insort_left,
2623 bisect_right and insort_right. The old names bisect and insort
2624 are now aliases for bisect_right and insort_right. XXX_right
2625 and XXX_left methods differ in what happens when the new element
2626 compares equal to one or more elements already in the list: the
2627 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002628 right. Code that doesn't care where equal elements end up should
2629 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002630
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002631- The new curses.panel module wraps the panel library that forms part
2632 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2633
Guido van Rossumf61f1662001-01-10 20:13:55 +00002634- The SocketServer module now sets the allow_reuse_address flag by
2635 default in the TCPServer class.
2636
2637- A new function, sys._getframe(), returns the stack frame pointer of
2638 the caller. This is intended only as a building block for
2639 higher-level mechanisms such as string interpolation.
2640
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002641- The pyexpat module supports a number of new handlers, which are
2642 available only in expat 1.2. If invocation of a callback fails, it
2643 will report an additional frame in the traceback. Parser objects
2644 participate now in garbage collection. If expat reports an unknown
2645 encoding, pyexpat will try to use a Python codec; that works only
2646 for single-byte charsets. The parser type objects is exposed as
2647 XMLParserObject.
2648
2649- xml.dom now offers standard definitions for symbolic node type and
2650 exception code constants, and a hierarchy of DOM exceptions. minidom
2651 was adjusted to use them.
2652
2653- The conformance of xml.dom.minidom to the DOM specification was
2654 improved. It detects a number of additional error cases; the
2655 previous/next relationship works even when the tree is modified;
2656 Node supports the normalize() method; NamedNodeMap, DocumentType and
2657 DOMImplementation classes were added; Element supports the
2658 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2659 method.
2660
Guido van Rossumf61f1662001-01-10 20:13:55 +00002661Build issues
2662
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002663- For Unix (and Unix-compatible) builds, configuration and building of
2664 extension modules is now greatly automated. Rather than having to
2665 edit the Modules/Setup file to indicate which modules should be
2666 built and where their include files and libraries are, a
2667 distutils-based setup.py script now takes care of building most
2668 extension modules. All extension modules built this way are built
2669 as shared libraries. Only a few modules that must be linked
2670 statically are still listed in the Setup file; you won't need to
2671 edit their configuration.
2672
2673- Python should now build out of the box on Cygwin. If it doesn't,
2674 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002675
2676- Python now always uses its own (renamed) implementation of getopt()
2677 -- there's too much variation among C library getopt()
2678 implementations.
2679
2680- C++ compilers are better supported; the CXX macro is always set to a
2681 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002682
Tim Petersd92dfe02000-12-12 01:18:41 +00002683Windows changes
2684
2685- select module: By default under Windows, a select() call
2686 can specify no more than 64 sockets. Python now boosts
2687 this Microsoft default to 512. If you need even more than
2688 that, see the MS docs (you'll need to #define FD_SETSIZE
2689 and recompile Python from source).
2690
Guido van Rossumf61f1662001-01-10 20:13:55 +00002691- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2692 subdirectory is no more!
2693
Tim Petersa3a3a032000-11-30 05:22:44 +00002694
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002695What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002696=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002697
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002698Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002699changes are in the file HISTORY. If you are making the jump directly
2700from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2701HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002702
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002703Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2704the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2705http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002706
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002707--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002708
2709======================================================================
2710
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002711What's new in 2.0 (since release candidate 1)?
2712==============================================
2713
2714Standard library
2715
2716- The copy_reg module was modified to clarify its intended use: to
2717 register pickle support for extension types, not for classes.
2718 pickle() will raise a TypeError if it is passed a class.
2719
2720- Fixed a bug in gettext's "normalize and expand" code that prevented
2721 it from finding an existing .mo file.
2722
2723- Restored support for HTTP/0.9 servers in httplib.
2724
Tim Peters989b7b92000-10-16 20:24:53 +00002725- The math module was changed to stop raising OverflowError in case of
2726 underflow, and return 0 instead in underflow cases. Whether Python
2727 used to raise OverflowError in case of underflow was platform-
2728 dependent (it did when the platform math library set errno to ERANGE
2729 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002730
2731- Fixed a bug in StringIO that occurred when the file position was not
2732 at the end of the file and write() was called with enough data to
2733 extend past the end of the file.
2734
2735- Fixed a bug that caused Tkinter error messages to get lost on
2736 Windows. The bug was fixed by replacing direct use of
2737 interp->result with Tcl_GetStringResult(interp).
2738
2739- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2740 redirect response.
2741
2742- Several changes were made to distutils: Some debugging code was
2743 removed from util. Fixed the installer used when an external zip
2744 program (like WinZip) is not found; the source code for this
2745 installer is in Misc/distutils. check_lib() was modified to behave
2746 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2747 test for whether installed modules are on sys.path was changed to
2748 use both normcase() and normpath().
2749
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002750- Several minor bugs were fixed in the xml package (the minidom,
2751 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002752
2753- The regression test driver (regrtest.py) behavior when invoked with
2754 -l changed: It now reports a count of objects that are recognized as
2755 garbage but not freed by the garbage collector.
2756
Tim Peters989b7b92000-10-16 20:24:53 +00002757- The regression test for the math module was changed to test
2758 exceptional behavior when the test is run in verbose mode. Python
2759 cannot yet guarantee consistent exception behavior across platforms,
2760 so the exception part of test_math is run only in verbose mode, and
2761 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002762
2763Internals
2764
2765- PyOS_CheckStack() has been disabled on Win64, where it caused
2766 test_sre to fail.
2767
2768Build issues
2769
2770- Changed compiler flags, so that gcc is always invoked with -Wall and
2771 -Wstrict-prototypes. Users compiling Python with GCC should see
2772 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002773 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002774 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002775
Tim Petersa3a3a032000-11-30 05:22:44 +00002776- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002777
2778Tools and other miscellany
2779
2780- The compiler in Tools/compiler was updated to support the new
2781 language features introduced in 2.0: extended print statement, list
2782 comprehensions, and augmented assignments. The new compiler should
2783 also be backwards compatible with Python 1.5.2; the compiler will
2784 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002785 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002786
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002787What's new in 2.0 release candidate 1 (since beta 2)?
2788=====================================================
2789
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002790What is release candidate 1?
2791
2792We believe that release candidate 1 will fix all known bugs that we
2793intend to fix for the 2.0 final release. This release should be a bit
2794more stable than the previous betas. We would like to see even more
2795widespread testing before the final release, so we are producing this
2796release candidate. The final release will be exactly the same unless
2797any show-stopping (or brown bag) bugs are found by testers of the
2798release candidate.
2799
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002800All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002801to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002802
2803Core language, builtins, and interpreter
2804
2805- A bug that caused crashes when __coerce__ was used with augmented
2806 assignment, e.g. +=, was fixed.
2807
2808- Raise ZeroDivisionError when raising zero to a negative number,
2809 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2810 power operator and the result of math.pow(0.0, -2.0) will vary by
2811 platform. On Linux, it raises a ValueError.
2812
2813- A bug in Unicode string interpolation was fixed that occasionally
2814 caused errors with formats including "%%". For example, the
2815 following expression "%% %s" % u"abc" no longer raises a TypeError.
2816
2817- Compilation of deeply nested expressions raises MemoryError instead
2818 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2819
2820- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2821 rendering them useless. They are now written in binary mode again.
2822
2823Standard library
2824
2825- Keyword arguments are now accepted for most pattern and match object
2826 methods in SRE, the standard regular expression engine.
2827
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002828- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002829 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002830
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002831- Several bugs in the Unicode handling and error handling in _tkinter
2832 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002833
2834- Fix memory management errors in Merge() and Tkapp_Call() routines.
2835
2836- Several changes were made to cStringIO to make it compatible with
2837 the file-like object interface and with StringIO. If operations are
2838 performed on a closed object, an exception is raised. The truncate
2839 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002840 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002841
2842- There were many changes made to the linuxaudiodev module and its
2843 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002844 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002845
2846 Note that this module is named poorly, because it should work
2847 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002848 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002849
2850 The module now raises exceptions when errors occur instead of
2851 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2852 audio) and defines a getptr() method that calls the
2853 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2854
2855- The library_version attribute, introduced in an earlier beta, was
2856 removed because it can not be supported with early versions of the C
2857 readline library, which provides no way to determine the version at
2858 compile-time.
2859
2860- The binascii module is now enabled on Win64.
2861
Tim Peters46446d62000-10-09 21:19:31 +00002862- tokenize.py no longer suffers "recursion depth" errors when parsing
2863 programs with very long string literals.
2864
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002865Internals
2866
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002867- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002868 which is called when the interpreter starts up to determine where
2869 the standard library is installed. These vulnerabilities affect all
2870 previous versions of Python and can be exploited by setting very
2871 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2872 setuid Python script, although use of the wrapper in
2873 Misc/setuid-prog.c will eliminate the vulnerability.
2874
2875- Fixed garbage collection bugs in instance creation that were
2876 triggered when errors occurred during initialization. The solution,
2877 applied in cPickle and in PyInstance_New(), is to call
2878 PyObject_GC_Init() after the initialization of the object's
2879 container attributes is complete.
2880
2881- pyexpat adds definitions of PyModule_AddStringConstant and
2882 PyModule_AddObject if the Python version is less than 2.0, which
2883 provides compatibility with PyXML on Python 1.5.2.
2884
2885- If the platform has a bogus definition for LONG_BIT (the number of
2886 bits in a long), an error will be reported at compile time.
2887
2888- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2889 collection crashes and possibly other, unreported crashes.
2890
2891- Fixed a memory leak in _PyUnicode_Fini().
2892
2893Build issues
2894
2895- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002896 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002897 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002898
2899- The mmap.PAGESIZE constant is now initialized using sysconf when
2900 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2901
2902- The md5 file should now compile on all platforms.
2903
2904- The select module now compiles on platforms that do not define
2905 POLLRDNORM and related constants.
2906
2907- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002908 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002909
Jeremy Hylton10921202000-10-09 18:34:12 +00002910- BeOS: A number of changes were made to the build and installation
2911 process. ar-fake now operates on a directory of object files.
2912 dl_export.h is gone, and its macros now appear on the mwcc command
2913 line during build on PPC BeOS.
2914
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002915- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002916 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002917
2918- Cygwin: Support for shared libraries, Tkinter, and sockets.
2919
2920- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2921
2922Tools and other miscellany
2923
2924- Removed debugging prints from main used with freeze.
2925
Tim Peters46446d62000-10-09 21:19:31 +00002926- IDLE auto-indent no longer crashes when it encounters Unicode
2927 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002928
2929What's new in 2.0 beta 2 (since beta 1)?
2930========================================
2931
2932Core language, builtins, and interpreter
2933
Tim Peters482c0212000-09-26 06:33:09 +00002934- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002935 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002936
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002937- Add -h and -V command line options to print the usage message and
2938 Python version number and exit immediately.
2939
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002940- eval() and exec accept Unicode objects as code parameters.
2941
2942- getattr() and setattr() now also accept Unicode objects for the
2943 attribute name, which are converted to strings using the default
2944 encoding before lookup.
2945
2946- Multiplication on string and Unicode now does proper bounds
2947 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2948 string is too long."
2949
2950- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002951 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002952
Jeremy Hylton1b618592000-09-26 05:32:36 +00002953
2954Standard library and extensions
2955
Guido van Rossum5b08f132001-04-16 02:05:23 +00002956- socket module: the OpenSSL code now adds support for RAND_status()
2957 and EGD (Entropy Gathering Device).
2958
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002959- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002960 argument checking; it still takes no arguments.
2961
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002962- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002963
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002964- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002965
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002966- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002967
2968- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002969 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002970
2971- copy: Copy Unicode objects atomically.
2972
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002973- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002974
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002975- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002976
Fred Drake67233bc2000-09-26 16:40:27 +00002977- dbm: Add get() and setdefault() methods to dbm object. Add constant
2978 `library' to module that names the library used. Added doc strings
2979 and method names to error messages. Uses configure to determine
2980 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2981 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002982
2983- distutils: Update to version 0.9.3.
2984
2985- dl: Add several dl.RTLD_ constants.
2986
2987- fpectl: Now supported on FreeBSD.
2988
2989- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2990 found by the collector will be saved in gc.garbage. This is useful
2991 for debugging a program that creates reference cycles.
2992
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002993- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002994 of HTTP class. Do not close socket on zero-length response. Do not
2995 crash when server sends invalid content-length header.
2996
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002997- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002998
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002999- marshal: When reading a short, sign-extend on platforms where shorts
3000 are bigger than 16 bits. When reading a long, repair the unportable
3001 sign extension that was being done for 64-bit machines. (It assumed
3002 that signed right shift sign-extends.)
3003
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003004- operator: Add contains(), invert(), __invert__() as aliases for
3005 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003006
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003007- os: Add support for popen2() and popen3() on all platforms where
3008 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003009
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003010- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00003011 clicking on a file in Explorer (or passing the file name to the
3012 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003013
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003014- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00003015 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00003016
3017- pickle: Now raises ValueError when an invalid pickle that contains
3018 a non-string repr where a string repr was expected. This behavior
3019 matches cPickle.
3020
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003021- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003022
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003023- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003024
3025- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003026 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003027 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00003028
3029- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003030 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003031
3032- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00003033 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00003034 few cycles during startup since the first call to
3035 setdefaultencoding() will initialize the codec registry and the
3036 encodings package.
3037
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003038- socket: Support for size hint in readlines() method of object returned
3039 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003040
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003041- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00003042 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00003043 is followed by whitespace.
3044
Tim Petersa3a3a032000-11-30 05:22:44 +00003045- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003046
3047- struct: Check ranges for bytes and shorts.
3048
3049- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003050 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003051
3052- Tkinter: Image objects are now guaranteed to have unique ids. Set
3053 event.delta to zero if Tk version doesn't support mousewheel.
3054 Removed some debugging prints.
3055
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003056- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00003057
Fred Drake67233bc2000-09-26 16:40:27 +00003058- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003059 which works around a bug in Norton AntiVirus 2000 that leads directly
3060 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003061
3062- xml: New version detection code allows PyXML to override standard
3063 XML package if PyXML version is greater than 0.6.1.
3064
Fred Drake64bb3802000-09-26 16:21:35 +00003065- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
3066 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
3067 tree only for nodes which are sufficiently interesting to a specific
3068 application. Does not provide the HTML-specific extensions. Still
3069 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003070
Fred Drake64bb3802000-09-26 16:21:35 +00003071- xml.sax: SAX 2 support for Python, including all the handler
3072 interfaces needed to process XML 1.0 compliant XML. Some
3073 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003074
Fred Drake64bb3802000-09-26 16:21:35 +00003075- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
3076 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003077
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003078
Jeremy Hylton1b618592000-09-26 05:32:36 +00003079C API
3080
3081- Add three new convenience functions for module initialization --
3082 PyModule_AddObject(), PyModule_AddIntConstant(), and
3083 PyModule_AddStringConstant().
3084
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003085- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00003086 removed and add #error to Python.h if NULL isn't defined after
3087 #include of stdio.h.
3088
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003089- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00003090 backwards compatibility (at the source level) with old extensions.
3091
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003092- A wrapper API was added for signal() and sigaction(). Instead of
3093 either function, always use PyOS_getsig() to get a signal handler
3094 and PyOS_setsig() to set one. A new convenience typedef
3095 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003096
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003097- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003098 internal data buffer and size of a string object -- or the default
3099 encoded version of a Unicode object.
3100
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003101- PyString_Size() and PyString_AsString() accept Unicode objects.
3102
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003103- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003104 exists). INT_MAX and LONG_MAX will always be defined, even if
3105 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003106
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003107- PyFloat_FromString takes a second argument, pend, that was
3108 effectively useless. It is now officially useless but preserved for
3109 backwards compatibility. If the pend argument is not NULL, *pend is
3110 set to NULL.
3111
3112- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3113 for the attribute name. See note on getattr() above.
3114
3115- A few bug fixes to argument processing for Unicode.
3116 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3117 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3118 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003119 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003120
3121- Py_BuildValue accepts B format (for bgen-generated code).
3122
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003123
Jeremy Hylton1b618592000-09-26 05:32:36 +00003124Internals
3125
3126- On Unix, fix code for finding Python installation directory so that
3127 it works when argv[0] is a relative path.
3128
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003129- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003130 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003131 rather than by generating a copy of the object.
3132
Tim Peters482c0212000-09-26 06:33:09 +00003133- Several of the internal Unicode tables are much smaller now, and
3134 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003135
Jeremy Hylton97693b02000-09-26 17:42:51 +00003136- In the garbage collector: Fixed bug in collection of tuples. Fixed
3137 bug that caused some instances to be removed from the container set
3138 while they were still live. Fixed parsing in gc.set_debug() for
3139 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003140
3141- Fixed refcount problem in instance deallocation that only occurred
3142 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3143
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003144- On Windows, getpythonregpath is now protected against null data in
3145 registry key.
3146
3147- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003148 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003149
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003150
Jeremy Hylton1b618592000-09-26 05:32:36 +00003151Build and platform-specific issues
3152
3153- Better support of GNU Pth via --with-pth configure option.
3154
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003155- Python/C API now properly exposed to dynamically-loaded extension
3156 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003157
3158- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3159 Don't define MS_SYNC to be zero when it is undefined. Added missing
3160 prototypes in posixmodule.c.
3161
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003162- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003163 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003164
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003165- Fix largefile support on older NetBSD systems and OpenBSD by adding
3166 define for TELL64.
3167
3168
3169Tools and other miscellany
3170
3171- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3172
3173- freeze: The modulefinder now works with 2.0 opcodes.
3174
Tim Petersa3a3a032000-11-30 05:22:44 +00003175- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003176 Move hackery of sys.argv until after the Tk instance has been
3177 created, which allows the application-specific Tkinter
3178 initialization to be executed if present; also pass an explicit
3179 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003180
Jeremy Hylton1b618592000-09-26 05:32:36 +00003181
3182What's new in 2.0 beta 1?
3183=========================
3184
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003185Source Incompatibilities
3186------------------------
3187
3188None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3189such as single-argument append(), connect() and bind(), and changes to
3190str(long) and repr(float).
3191
3192
3193Binary Incompatibilities
3194------------------------
3195
3196- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3197with Python 2.0; these extensions will have to be rebuilt for Python
31982.0.
3199
3200- On Windows, attempting to import a third party extension built for
3201Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3202can do about this. Check your PYTHONPATH environment variable!
3203
3204- Python bytecode files (*.pyc and *.pyo) are not compatible between
3205releases.
3206
3207
3208Overview of Changes Since 1.6
3209-----------------------------
3210
3211There are many new modules (including brand new XML support through
3212the xml package, and i18n support through the gettext module); a list
3213of all new modules is included below. Lots of bugs have been fixed.
3214
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003215The process for making major new changes to the language has changed
3216since Python 1.6. Enhancements must now be documented by a Python
3217Enhancement Proposal (PEP) before they can be accepted.
3218
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003219There are several important syntax enhancements, described in more
3220detail below:
3221
3222 - Augmented assignment, e.g. x += 1
3223
3224 - List comprehensions, e.g. [x**2 for x in range(10)]
3225
3226 - Extended import statement, e.g. import Module as Name
3227
3228 - Extended print statement, e.g. print >> file, "Hello"
3229
3230Other important changes:
3231
3232 - Optional collection of cyclical garbage
3233
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003234Python Enhancement Proposal (PEP)
3235---------------------------------
3236
3237PEP stands for Python Enhancement Proposal. A PEP is a design
3238document providing information to the Python community, or describing
3239a new feature for Python. The PEP should provide a concise technical
3240specification of the feature and a rationale for the feature.
3241
3242We intend PEPs to be the primary mechanisms for proposing new
3243features, for collecting community input on an issue, and for
3244documenting the design decisions that have gone into Python. The PEP
3245author is responsible for building consensus within the community and
3246documenting dissenting opinions.
3247
3248The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003249
3250Augmented Assignment
3251--------------------
3252
3253This must have been the most-requested feature of the past years!
3254Eleven new assignment operators were added:
3255
Guido van Rossume905e952000-09-05 12:42:46 +00003256 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003257
3258For example,
3259
3260 A += B
3261
3262is similar to
3263
3264 A = A + B
3265
3266except that A is evaluated only once (relevant when A is something
3267like dict[index].attr).
3268
3269However, if A is a mutable object, A may be modified in place. Thus,
3270if A is a number or a string, A += B has the same effect as A = A+B
3271(except A is only evaluated once); but if a is a list, A += B has the
3272same effect as A.extend(B)!
3273
3274Classes and built-in object types can override the new operators in
3275order to implement the in-place behavior; the not-in-place behavior is
3276used automatically as a fallback when an object doesn't implement the
3277in-place behavior. For classes, the method name is derived from the
3278method name for the corresponding not-in-place operator by inserting
3279an 'i' in front of the name, e.g. __iadd__ implements in-place
3280__add__.
3281
3282Augmented assignment was implemented by Thomas Wouters.
3283
3284
3285List Comprehensions
3286-------------------
3287
3288This is a flexible new notation for lists whose elements are computed
3289from another list (or lists). The simplest form is:
3290
3291 [<expression> for <variable> in <sequence>]
3292
Guido van Rossum56db0952000-09-06 23:34:25 +00003293For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003294This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003295
3296You can also add a condition:
3297
3298 [<expression> for <variable> in <sequence> if <condition>]
3299
3300For example, [w for w in words if w == w.lower()] would yield the list
3301of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003302than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003303
3304You can also have nested for loops and more than one 'if' clause. For
3305example, here's a function that flattens a sequence of sequences::
3306
3307 def flatten(seq):
3308 return [x for subseq in seq for x in subseq]
3309
3310 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3311
3312This prints
3313
3314 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3315
3316List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003317Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003318
3319
3320Extended Import Statement
3321-------------------------
3322
3323Many people have asked for a way to import a module under a different
3324name. This can be accomplished like this:
3325
3326 import foo
3327 bar = foo
3328 del foo
3329
3330but this common idiom gets old quickly. A simple extension of the
3331import statement now allows this to be written as follows:
3332
3333 import foo as bar
3334
3335There's also a variant for 'from ... import':
3336
3337 from foo import bar as spam
3338
3339This also works with packages; e.g. you can write this:
3340
3341 import test.regrtest as regrtest
3342
3343Note that 'as' is not a new keyword -- it is recognized only in this
3344context (this is only possible because the syntax for the import
3345statement doesn't involve expressions).
3346
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003347Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003348
3349
3350Extended Print Statement
3351------------------------
3352
3353Easily the most controversial new feature, this extension to the print
3354statement adds an option to make the output go to a different file
3355than the default sys.stdout.
3356
3357For example, to write an error message to sys.stderr, you can now
3358write:
3359
3360 print >> sys.stderr, "Error: bad dog!"
3361
3362As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003363evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003364
3365 print >> None, "Hello world"
3366
3367is equivalent to
3368
3369 print "Hello world"
3370
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003371Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003372
3373
3374Optional Collection of Cyclical Garbage
3375---------------------------------------
3376
3377Python is now equipped with a garbage collector that can hunt down
3378cyclical references between Python objects. It's no replacement for
3379reference counting; in fact, it depends on the reference counts being
3380correct, and decides that a set of objects belong to a cycle if all
3381their reference counts can be accounted for from their references to
3382each other. This devious scheme was first proposed by Eric Tiedemann,
3383and brought to implementation by Neil Schemenauer.
3384
3385There's a module "gc" that lets you control some parameters of the
3386garbage collection. There's also an option to the configure script
3387that lets you enable or disable the garbage collection. In 2.0b1,
3388it's on by default, so that we (hopefully) can collect decent user
3389experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003390performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003391off by default in the final 2.0 release.
3392
3393
3394Smaller Changes
3395---------------
3396
3397A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3398map(None, seq1, seq2, ...) when the sequences have the same length;
3399i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3400the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003401zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003402
3403sys.version_info is a tuple (major, minor, micro, level, serial).
3404
3405Dictionaries have an odd new method, setdefault(key, default).
3406dict.setdefault(key, default) returns dict[key] if it exists; if not,
3407it sets dict[key] to default and returns that value. Thus:
3408
3409 dict.setdefault(key, []).append(item)
3410
3411does the same work as this common idiom:
3412
3413 if not dict.has_key(key):
3414 dict[key] = []
3415 dict[key].append(item)
3416
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003417There are two new variants of SyntaxError that are raised for
3418indentation-related errors: IndentationError and TabError.
3419
3420Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3421escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003422
3423The limits on the size of expressions and file in Python source code
3424have been raised from 2**16 to 2**32. Previous versions of Python
3425were limited because the maximum argument size the Python VM accepted
3426was 2**16. This limited the size of object constructor expressions,
3427e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3428limit was raised thanks to a patch by Charles Waldman that effectively
3429fixes the problem. It is now much more likely that you will be
3430limited by available memory than by an arbitrary limit in Python.
3431
3432The interpreter's maximum recursion depth can be modified by Python
3433programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3434limit is the maximum number of recursive calls that can be made by
3435Python code. The limit exists to prevent infinite recursion from
3436overflowing the C stack and causing a core dump. The default value is
34371000. The maximum safe value for a particular platform can be found
3438by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003439
3440New Modules and Packages
3441------------------------
3442
3443atexit - for registering functions to be called when Python exits.
3444
3445imputil - Greg Stein's alternative API for writing custom import
3446hooks.
3447
3448pyexpat - an interface to the Expat XML parser, contributed by Paul
3449Prescod.
3450
3451xml - a new package with XML support code organized (so far) in three
3452subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3453would fill a volume. There's a special feature whereby a
3454user-installed package named _xmlplus overrides the standard
3455xmlpackage; this is intended to give the XML SIG a hook to distribute
3456backwards-compatible updates to the standard xml package.
3457
3458webbrowser - a platform-independent API to launch a web browser.
3459
3460
Guido van Rossume905e952000-09-05 12:42:46 +00003461Changed Modules
3462---------------
3463
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003464array -- new methods for array objects: count, extend, index, pop, and
3465remove
3466
3467binascii -- new functions b2a_hex and a2b_hex that convert between
3468binary data and its hex representation
3469
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003470calendar -- Many new functions that support features including control
3471over which day of the week is the first day, returning strings instead
3472of printing them. Also new symbolic constants for days of week,
3473e.g. MONDAY, ..., SUNDAY.
3474
3475cgi -- FieldStorage objects have a getvalue method that works like a
3476dictionary's get method and returns the value attribute of the object.
3477
3478ConfigParser -- The parser object has new methods has_option,
3479remove_section, remove_option, set, and write. They allow the module
3480to be used for writing config files as well as reading them.
3481
3482ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003483optionally support the RFC 959 REST command.
3484
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003485gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003486
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003487httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3488the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003489
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003490locale -- implement getdefaultlocale for Win32 and Macintosh
3491
3492marshal -- no longer dumps core when marshaling deeply nested or
3493recursive data structures
3494
3495os -- new functions isatty, seteuid, setegid, setreuid, setregid
3496
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003497os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3498support under Unix.
3499
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003500os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003501
3502os.path -- fix semantics of os.path.commonprefix
3503
3504smtplib -- support for sending very long messages
3505
3506socket -- new function getfqdn()
3507
3508readline -- new functions to read, write and truncate history files.
3509The readline section of the library reference manual contains an
3510example.
3511
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003512select -- add interface to poll system call
3513
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003514shutil -- new copyfileobj function
3515
3516SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3517HTTP server.
3518
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003519Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003520
3521urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003522e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003523
3524whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003525
3526
3527Obsolete Modules
3528----------------
3529
3530None. However note that 1.6 made a whole slew of modules obsolete:
3531stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3532poly, zmod, strop, util, whatsound.
3533
3534
3535Changed, New, Obsolete Tools
3536----------------------------
3537
Tim Peters8b092332000-09-05 20:15:25 +00003538None.
Guido van Rossume905e952000-09-05 12:42:46 +00003539
3540
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003541C-level Changes
3542---------------
3543
3544Several cleanup jobs were carried out throughout the source code.
3545
3546All C code was converted to ANSI C; we got rid of all uses of the
3547Py_PROTO() macro, which makes the header files a lot more readable.
3548
3549Most of the portability hacks were moved to a new header file,
3550pyport.h; several other new header files were added and some old
3551header files were removed, in an attempt to create a more rational set
3552of header files. (Few of these ever need to be included explicitly;
3553they are all included by Python.h.)
3554
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003555Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003556and Win64, especially for the new Intel Itanium processor. Mick also
3557added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003558
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003559The C APIs to return an object's size have been update to consistently
3560use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3561previous versions, the abstract interfaces used PyXXX_Length and the
3562concrete interfaces used PyXXX_Size. The old names,
3563e.g. PyObject_Length, are still available for backwards compatibility
3564at the API level, but are deprecated.
3565
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003566The PyOS_CheckStack function has been implemented on Windows by
3567Fredrik Lundh. It prevents Python from failing with a stack overflow
3568on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003569
3570The GC changes resulted in creation of two new slots on object,
3571tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003572the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003573
3574The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003575C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003576
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003577PyErr_Format has been updated to automatically calculate the size of
3578the buffer needed to hold the formatted result string. This change
3579prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003580
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003581New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003582
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003583PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3584that are the same as their non-Ex counterparts except they take an
3585extra flag argument that tells them to close the file when done.
3586
3587XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003588
Tim Peters8b092332000-09-05 20:15:25 +00003589
3590Windows Changes
3591---------------
3592
3593New popen2/popen3/peopen4 in os module (see Changed Modules above).
3594
3595os.popen is much more usable on Windows 95 and 98. See Microsoft
3596Knowledge Base article Q150956. The Win9x workaround described there
3597is implemented by the new w9xpopen.exe helper in the root of your
3598Python installation. Note that Python uses this internally; it is not
3599a standalone program.
3600
3601Administrator privileges are no longer required to install Python
3602on Windows NT or Windows 2000. If you have administrator privileges,
3603Python's registry info will be written under HKEY_LOCAL_MACHINE.
3604Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003605under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003606uses of Python, but will prevent some advanced uses from working
3607(for example, running a Python script as an NT service, or possibly
3608from CGI).
3609
3610[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3611installer; instead, it installs the needed Tcl/Tk files directly in the
3612Python directory. If you already have a Tcl/Tk installation, this
3613wastes some disk space (about 4 Megs) but avoids problems with
3614conflicting Tcl/Tk installations, and makes it much easier for Python
3615to ensure that Tcl/Tk can find all its files.
3616
3617[This was new in 1.6] The Windows installer now installs by default in
3618\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3619
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003620
3621Updates to the changes between 1.5.2 and 1.6
3622--------------------------------------------
3623
3624The 1.6 NEWS file can't be changed after the release is done, so here
3625is some late-breaking news:
3626
3627New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3628and changes to getlocale() and setlocale().
3629
3630The new module is now enabled per default.
3631
3632It is not true that the encodings codecs cannot be used for normal
3633strings: the string.encode() (which is also present on 8-bit strings
3634!) allows using them for 8-bit strings too, e.g. to convert files from
3635cp1252 (Windows) to latin-1 or vice-versa.
3636
3637Japanese codecs are available from Tamito KAJIYAMA:
3638http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3639
3640
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003641======================================================================