blob: 383614f0593a152d4d23ccf0fc6da51be8164726 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Guido van Rossumc5fe5eb2002-06-12 03:45:21 +00009- Fixed a bug with a continue inside a try block and a yield in the
10 finally clause. [SF bug 567538]
11
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000012- Most builtin sequences now support "extended slices", i.e. slices
Guido van Rossum2e82e712002-06-13 11:41:07 +000013 with a third "stride" parameter. For example, "hello world"[::-1]
14 gives "dlrow olleh".
Michael W. Hudson5efaf7e2002-06-11 10:55:12 +000015
Guido van Rossum9f7549b2002-06-10 21:39:42 +000016- Cycles going through the __class__ link of a new-style instance are
17 now detected by the garbage collector.
18
Guido van Rossum9923ffe2002-06-04 19:52:53 +000019- Classes using __slots__ are now properly garbage collected.
20 [SF bug 519621]
21
22- Tightened the __slots__ rules: a slot name must be a valid Python
23 identifier.
24
Guido van Rossum2e4e0262002-06-04 05:58:34 +000025- The constructor for the module type now requires a name argument and
26 takes an optional docstring argument. Previously, this constructor
27 ignored its arguments. As a consequence, deriving a class from a
28 module (not from the module type) is now illegal; previously this
29 created an unnamed module, just like invoking the module type did.
30 [SF bug 563060]
31
Neal Norwitzd68f5172002-05-29 15:54:55 +000032- A new warning PendingDeprecationWarning was added to provide
33 direction on features which are in the process of being deprecated.
34 The warning will not be printed by default. To see the pending
35 deprecations, use -Walways::PendingDeprecationWarning::
36 as a command line option or warnings.filterwarnings() in code.
37
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000038- A new type object, 'basestring', is added. This is a common base type
Guido van Rossumcacfc072002-05-24 19:01:59 +000039 for 'str' and 'unicode', and can be used instead of
40 types.StringTypes, e.g. to test whether something is "a string":
Neal Norwitz32a7e7f2002-05-31 19:58:02 +000041 isinstance(x, basestring) is True for Unicode and 8-bit strings. This
Guido van Rossumcacfc072002-05-24 19:01:59 +000042 is an abstract base class and cannot be instantiated directly.
43
Fred Draked0ba6362002-05-02 21:28:26 +000044- Deprecated features of xrange objects have been removed as
45 promised. The start, stop, and step attributes and the tolist()
46 method no longer exist. xrange repetition and slicing have been
47 removed.
48
Guido van Rossum7dab2422002-04-26 19:40:56 +000049- New builtin function enumerate(x), from PEP 279. Example:
50 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
51 The argument can be an arbitrary iterable object.
52
Neil Schemenauer89e3ee02002-04-26 01:58:53 +000053- The assert statement no longer tests __debug__ at runtime. This means
54 that assert statements cannot be disabled by assigning a false value
55 to __debug__.
56
Walter Dörwald068325e2002-04-15 13:36:47 +000057- A method zfill() was added to str and unicode, that fills a numeric
58 string to the left with zeros. For example,
59 "+123".zfill(6) -> "+00123".
60
Guido van Rossum862fe3c2002-04-15 12:36:47 +000061- Complex numbers supported divmod() and the // and % operators, but
62 these make no sense. Since this was documented, they're being
63 deprecated now.
64
Guido van Rossum26dd8302002-04-26 20:11:29 +000065- String and unicode methods lstrip(), rstrip() and strip() now take
66 an optional argument that specifies the characters to strip. For
67 example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
Guido van Rossum49042042002-04-13 00:59:05 +000068
Guido van Rossumc69343b2002-04-12 19:22:48 +000069- Added a new dict method pop(key). This removes and returns the
70 value corresponding to key. [SF patch #539949]
71
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000072- Changed new-style class instantiation so that when C's __new__
73 method returns something that's not a C instance, its __init__ is
74 not called. [SF bug #537450]
75
Guido van Rossum181e41a2002-04-06 00:23:25 +000076- Fixed super() to work correctly with class methods. [SF bug #535444]
77
Guido van Rossum47834462002-04-04 15:21:33 +000078- A new built-in type, bool, has been added, as well as built-in
79 names for its two values, True and False. Comparisons and sundry
80 other operations that return a truth value have been changed to
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +000081 return a bool instead. Read PEP 285 for an explanation of why this
Guido van Rossum47834462002-04-04 15:21:33 +000082 is backward compatible.
83
Guido van Rossum95b62a62002-03-29 01:07:24 +000084- Fixed two bugs reported as SF #535905: under certain conditions,
85 deallocating a deeply nested structure could cause a segfault in the
86 garbage collector, due to interaction with the "trashcan" code;
87 access to the current frame during destruction of a local variable
88 could access a pointer to freed memory.
89
Neil Schemenauer9d50d132002-03-22 17:06:59 +000090- The optional object allocator has been enabled by default.
91
Guido van Rossum8c842552002-03-14 23:05:54 +000092- If you try to pickle an instance of a class that has __slots__ but
93 doesn't define or override __getstate__, a TypeError is now raised.
94 This is done by adding a bozo __getstate__ to the class that always
95 raises TypeError. (Before, this would appear to be pickled, but the
96 state of the slots would be lost.)
97
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000098- PyErr_Display will provide file and line information for all exceptions
99 that have an attribute print_file_and_line, not just SyntaxErrors.
100
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000101- The UTF-8 codec will now encode and decode Unicode surrogates
102 correctly and without raising exceptions for unpaired ones.
103
Neal Norwitz649b7592002-01-01 19:07:13 +0000104- file.xreadlines() now raises a ValueError if the file is closed:
105 Previously, an xreadlines object was returned which would raise
106 a ValueError when the xreadlines.next() method was called.
107
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000108- sys.exit() inadvertently allowed more than one argument.
Neal Norwitz0c766a02002-03-27 13:03:09 +0000109 An exception will now be raised if more than one argument is used.
110
Tim Petersaf8446f2001-12-21 21:36:50 +0000111Extension modules
112
Tim Peters81b92512002-04-29 01:37:32 +0000113- The bsddb.*open functions can now take 'None' as a filename.
Anthony Baxter83888952002-04-23 02:11:05 +0000114 This will create a temporary in-memory bsddb that won't be
Tim Peters81b92512002-04-29 01:37:32 +0000115 written to disk.
Anthony Baxter83888952002-04-23 02:11:05 +0000116
Martin v. Löwis606edc12002-06-13 21:09:11 +0000117- posix.killpg, posix.mknod, and posix.getpgid have been added where
118 available.
Martin v. Löwis06a83e92002-04-14 10:19:44 +0000119
Martin v. Löwis2e64c342002-03-27 18:49:02 +0000120- The locale module now exposes the C library's gettext interface.
121
Tim Petersfbf74f22002-03-14 19:06:01 +0000122- A security hole ("double free") was found in zlib-1.1.3, a popular
123 third party compression library used by some Python modules. The
124 hole was quickly plugged in zlib-1.1.4, and the Windows build of
125 Python now ships with zlib-1.1.4.
126
Martin v. Löwis688357e2002-04-08 21:28:20 +0000127- pwd, grp, and resource return enhanced tuples now, with symbolic
128 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +0000129
Martin v. Löwis99866332002-03-01 10:27:01 +0000130- array.array is now a type object. A new format character
131 'u' indicates Py_UNICODE arrays. For those, .tounicode and
132 .fromunicode methods are available. Arrays now support __iadd__
133 and __imul__.
134
Neal Norwitze790eae2002-01-01 21:14:12 +0000135- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +0000136 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
137 is called.
138
Michael W. Hudson34f20ea2002-05-27 15:08:24 +0000139- signal.sigpending, signal.sigprocmask and signal.sigsuspend have
140 been added where available.
141
Tim Petersaf8446f2001-12-21 21:36:50 +0000142Library
143
Guido van Rossum9f7549b2002-06-10 21:39:42 +0000144- Some fixes in the copy module: when an object is copied through its
145 __reduce__ method, there was no check for a __setstate__ method on
146 the result [SF patch 565085]; deepcopy should treat instances of
147 custom metaclasses the same way it treats instances of type 'type'
148 [SF patch 560794].
149
Guido van Rossum5033c8e2002-06-07 12:40:52 +0000150- Sockets now support timeout mode. After s.settimeout(T), where T is
151 a float expressing seconds, subsequent operations raise an exception
152 if they cannot be completed within T seconds. To disable timeout
153 mode, use s.settimeout(None).
154
155- getopt.gnu_getopt was added. This supports GNU-style option
156 processing, where options can be mixed with non-option arguments.
Martin v. Löwis446a25f2002-06-06 10:58:36 +0000157
Michael W. Hudsonb0dc1a32002-06-04 18:27:35 +0000158- Stop using strings for exceptions. String objects used for
159 exceptions are now classes deriving from Exception. The objects
160 changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
161 tabnanny.NannyNag, and xdrlib.Error.
Neal Norwitzb5b5a262002-06-04 17:14:07 +0000162
Walter Dörwald474458d2002-06-04 15:16:29 +0000163- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
164 BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
165 Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
166 big endian systems were added to the codecs module. The old names
167 BOM32_* and BOM64_* were off by a factor of 2.
168
Raymond Hettinger87f59ee2002-05-13 04:17:32 +0000169- added degree/radian conversion functions to the math module.
170
Raymond Hettinger9b1df1d2002-05-12 06:07:21 +0000171- ftplib.retrlines() now tests for callback is None rather than testing
172 for False. Was causing an error when given a callback object which
173 was callable but also returned len() as zero. The change may
174 create new breakage if the caller relied on the undocumented behavior
175 and called with callback set to [] or some other False value not
176 identical to None.
177
Tim Peters46c04e12002-05-05 20:40:00 +0000178- random.gauss() uses a piece of hidden state used by nothing else,
179 and the .seed() and .whseed() methods failed to reset it. In other
180 words, setting the seed didn't completely determine the sequence of
181 results produced by random.gauss(). It does now. Programs repeatedly
182 mixing calls to a seed method with calls to gauss() may see different
183 results now.
184
Fred Drake7f781c92002-05-01 20:33:53 +0000185- The pickle.Pickler class grew a clear_memo() method to mimic that
186 provided by cPickle.Pickler.
187
Tim Peters81b92512002-04-29 01:37:32 +0000188- difflib's SequenceMatcher class now does a dynamic analysis of
189 which elements are so frequent as to constitute noise. For
190 comparing files as sequences of lines, this generally works better
191 than the IS_LINE_JUNK function, and function ndiff's linejunk
192 argument defaults to None now as a result. A happy benefit is
193 that SequenceMatcher may run much faster now when applied
194 to large files with many duplicate lines (for example, C program
195 text with lots of repeated "}" and "return NULL;" lines).
196
Guido van Rossum256705b2002-04-23 13:29:43 +0000197- New Text.dump() method in Tkinter module.
198
Marc-André Lemburg1ec71ea2002-04-17 20:33:40 +0000199- New distutils commands for building packagers were added to
200 support pkgtool on Solaris and swinstall on HP-UX.
201
202- distutils now has a new abstract binary packager base class
203 command/bdist_packager, which simplifies writing packagers.
204 This will hopefully provide the missing bits to encourage
205 people to submit more packagers, e.g. for Debian, FreeBSD
206 and other systems.
207
Marc-André Lemburg4179a012002-04-05 12:15:05 +0000208- The UTF-16, -LE and -BE now raise a NotImplementedError
209 for all calls to .readline(). Previously, they used to just
210 produce garbage or fail with an encoding error -- UTF-16 is
211 a 2-byte encoding and the C lib's line reading APIs don't
212 work well with these.
213
Martin v. Löwis5c137c22002-03-18 12:44:08 +0000214- compileall now supports quiet operation.
215
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000216- The BaseHTTPServer now implements optional HTTP/1.1 persistent
Martin v. Löwis587c98c2002-03-17 18:37:22 +0000217 connections.
218
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +0000219- socket module: the SSL support was broken out of the main
220 _socket module C helper and placed into a new _ssl helper
221 which now gets imported by socket.py if available and working.
222
Marc-André Lemburg37aa5802002-02-10 21:42:47 +0000223- encodings package: added aliases for all supported IANA character
224 sets
225
Guido van Rossum606fe4e2001-12-28 20:57:14 +0000226- ftplib: to safeguard the user's privacy, anonymous login will use
227 "anonymous@" as default password, rather than the real user and host
228 name.
229
Fred Drake36736122002-01-10 13:50:31 +0000230- webbrowser: tightened up the command passed to os.system() so that
231 arbitrary shell code can't be executed because a bogus URL was
232 passed in.
233
Tim Peters11bd9942002-02-01 00:52:29 +0000234- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000235 gettext.find an optional all argument. Translations will now fallback
236 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000237
Martin v. Löwis9668b932002-01-12 11:27:42 +0000238- distutils bdist commands now offer a --skip-build option.
239
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000240- warnings.warn now accepts a Warning instance as first argument.
241
Fred Drakefed7e852002-04-04 19:36:15 +0000242- The xml.sax.expatreader.ExpatParser class will no longer create
243 circular references by using itself as the locator that gets passed
244 to the content handler implementation. [SF bug #535474]
245
Barry Warsaw47f3e2c2002-05-20 00:14:24 +0000246- The email.Parser.Parser class now properly parses strings regardless
247 of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
248 or CRLF). Also, the Header class's constructor default arguments
249 has changed slightly so that an explicit maxlinelen value is always
250 honored.
251
Tim Petersaf8446f2001-12-21 21:36:50 +0000252Tools/Demos
253
Marc-André Lemburg46260092002-04-04 16:17:11 +0000254- freeze.py now produces binaries which can import shared modules,
255 unlike before when this failed due to missing symbol exports in
256 the generated binary.
257
Tim Petersaf8446f2001-12-21 21:36:50 +0000258Build
259
Martin v. Löwisa3fb4f72002-06-09 13:33:54 +0000260- The configure option --without-doc-strings can be used to remove the
261 doc strings from the builtin functions and modules; this reduces the
262 size of the executable.
263
Tim Peters639295f2002-04-21 07:30:30 +0000264- XXX WITH_UNIVERSAL_NEWLINES Somebody fill this in; the PEP doesn't
265 say how or when to configure it, or how to turn it off.
266
Martin v. Löwis1142de32002-03-29 16:28:31 +0000267- On Unix, a shared libpython2.3.so can be created with --enable-shared.
268
Tim Peters8deda702002-03-30 10:06:07 +0000269- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
270 preprocessor symbols were eliminated. The internal decisions they
271 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000272
Fred Drake7d28b732002-05-02 21:17:00 +0000273- The tools used to build the documentation now work under Cygwin as
274 well as Unix.
275
Tim Petersaf8446f2001-12-21 21:36:50 +0000276C API
277
Martin v. Löwis01f94bd2002-05-08 08:44:21 +0000278- Added new macro PySequence_ITEM(o, i) that directly calls
279 sq_item without rechecking that o is a sequence and without
280 adjusting for negative indices.
281
Fred Draked0ba6362002-05-02 21:28:26 +0000282- PyRange_New() now raises ValueError if the fourth argument is not 1.
283 This is part of the removal of deprecated features of the xrange
284 object.
285
Guido van Rossum517c7d42002-04-26 02:49:14 +0000286- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
287 coercion if both arguments have the same type but this type has the
288 CHECKTYPES flag set. This is to better support proxies.
289
Neil Schemenauer9344b142002-04-12 23:00:08 +0000290- The type of tp_free has been changed from "void (*)(PyObject *)" to
291 "void (*)(void *)".
292
293- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
294
Guido van Rossum0986d822002-04-08 01:38:42 +0000295- A type can now inherit its metatype from its base type. Previously,
296 when PyType_Ready() was called, if ob_type was found to be NULL, it
297 was always set to &PyType_Type; now it is set to base->ob_type,
298 where base is tp_base, defaulting to &PyObject_Type.
299
300- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
301
Neil Schemenauerc9abc1d2002-05-08 14:14:41 +0000302- The PyCore_* family of APIs have been removed.
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000303
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000304- The "u#" parser marker will now pass through Unicode objects as-is
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000305 without going through the buffer API.
306
Martin v. Löwis7198a522002-01-01 19:59:11 +0000307- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
308
Tim Peters10a3bb52001-12-25 19:07:38 +0000309- An old #define of ANY as void has been removed from pyport.h. This
310 hasn't been used since Python's pre-ANSI days, and the #define has
311 been marked as obsolete since then. SF bug 495548 says it created
312 conflicts with other packages, so keeping it around wasn't harmless.
313
Tim Petersaf8446f2001-12-21 21:36:50 +0000314- Because Python's magic number scheme broke on January 1st, we decided
315 to stop Python development. Thanks for all the fish!
316
Tim Petersfb05db22002-03-11 00:24:00 +0000317- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000318 scheme to a new one. See Python/import.c for details.
319
Tim Petersaf8446f2001-12-21 21:36:50 +0000320New platforms
321
Martin v. Löwisf90ae202002-06-11 06:22:31 +0000322- AtheOS is now supported.
323
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000324- GNU/Hurd is now supported.
325
Tim Petersaf8446f2001-12-21 21:36:50 +0000326Tests
327
328Windows
329
Tim Peters08e72952002-04-16 20:48:01 +0000330- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
331 of that has been fixed in the installer (disabled Wise's "delete in-
332 use files" uninstall option).
333
Guido van Rossum181e41a2002-04-06 00:23:25 +0000334- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
335
Tim Peters33187922002-04-04 20:02:04 +0000336- The installer now installs Start menu shortcuts under (the local
337 equivalent of) "All Users" when doing an Admin install.
338
Tim Petersfb05db22002-03-11 00:24:00 +0000339- file.truncate([newsize]) now works on Windows for all newsize values.
340 It used to fail if newsize didn't fit in 32 bits, reflecting a
341 limitation of MS _chsize (which is no longer used).
342
Tim Petersab034fa2002-02-01 11:27:43 +0000343- os.waitpid() is now implemented for Windows, and can be used to block
344 until a specified process exits. This is similar to, but not exactly
345 the same as, os.waitpid() on POSIX systems. If you're waiting for
346 a specific process whose pid was obtained from one of the spawn()
347 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000348 See the docs for details. The docs were changed to clarify that
349 spawn functions return, and waitpid requires, a process handle on
350 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000351
Tim Peters11bd9942002-02-01 00:52:29 +0000352- New tempfile.TemporaryFile implementation for Windows: this doesn't
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000353 need a TemporaryFileWrapper wrapper anymore, and should be immune
Tim Peters11bd9942002-02-01 00:52:29 +0000354 to a nasty problem: before 2.3, if you got a temp file on Windows, it
355 got wrapped in an object whose close() method first closed the
356 underlying file, then deleted the file. This usually worked fine.
357 However, the spawn family of functions on Windows create (at a low C
358 level) the same set of open files in the spawned process Q as were
359 open in the spawning process P. If a temp file f was among them, then
360 doing f.close() in P first closed P's C-level file handle on f, but Q's
361 C-level file handle on f remained open, so the attempt in P to delete f
362 blew up with a "Permission denied" error (Windows doesn't allow
363 deleting open files). This was surprising, subtle, and difficult to
364 work around.
365
366- The os module now exports all the symbolic constants usable with the
367 low-level os.open() on Windows: the new constants in 2.3 are
368 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
369 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
370 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
371 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
372 (so specify both if you want both; note that neither is useful unless
373 specified with O_CREAT too).
374
Tim Petersaf8446f2001-12-21 21:36:50 +0000375Mac
376
377
Tim Peters909c0912001-12-14 23:16:18 +0000378What's New in Python 2.2 final?
379Release date: 21-Dec-2001
380===============================
381
382Type/class unification and new-style classes
383
Barry Warsaw52acb492001-12-21 20:04:22 +0000384- pickle.py, cPickle: allow pickling instances of new-style classes
385 with a custom metaclass.
386
Tim Peters909c0912001-12-14 23:16:18 +0000387Core and builtins
388
Barry Warsaw52acb492001-12-21 20:04:22 +0000389- weakref proxy object: when comparing, unwrap both arguments if both
390 are proxies.
391
Tim Peters909c0912001-12-14 23:16:18 +0000392Extension modules
393
Barry Warsaw52acb492001-12-21 20:04:22 +0000394- binascii.b2a_base64(): fix a potential buffer overrun when encoding
395 very short strings.
396
397- cPickle: the obscure "fast" mode was suspected of causing stack
398 overflows on the Mac. Hopefully fixed this by setting the recursion
399 limit much smaller. If the limit is too low (it only affects
400 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
401 when compiling cPickle.c (or in pyconfig.h).
402
Tim Peters909c0912001-12-14 23:16:18 +0000403Library
404
Barry Warsaw52acb492001-12-21 20:04:22 +0000405- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
406 close or delete time).
407
408- rfc822.py: fixed a bug where the address '<>' was converted to None
409 instead of an empty string (also fixes the email.Utils module).
410
411- xmlrpclib.py: version 1.0.0; uses precision for doubles.
412
413- test suite: the pickle and cPickle tests were not executing any code
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000414 when run from the standard regression test.
Barry Warsaw52acb492001-12-21 20:04:22 +0000415
Tim Peters909c0912001-12-14 23:16:18 +0000416Tools/Demos
417
418Build
419
420C API
421
422New platforms
423
424Tests
425
426Windows
427
Barry Warsaw52acb492001-12-21 20:04:22 +0000428- distutils package: fixed broken Windows installers (bdist_wininst).
429
430- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
431 instances are deleted at process exit time.
432
433- socket.py: prevent mysterious warnings when socket instances are
434 deleted at process exit time.
435
436- posixmodule.c: fix a Windows crash with stat() of a filename ending
437 in backslash.
438
Tim Peters909c0912001-12-14 23:16:18 +0000439Mac
440
Barry Warsaw52acb492001-12-21 20:04:22 +0000441- The Carbon toolbox modules have been upgraded to Universal Headers
442 3.4, and experimental CoreGraphics and CarbonEvents modules have
443 been added. All only for framework-enabled MacOSX.
444
Tim Peters909c0912001-12-14 23:16:18 +0000445
Tim Peters6272dfd2001-12-13 19:34:00 +0000446What's New in Python 2.2c1?
447Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000448===========================
449
450Type/class unification and new-style classes
451
Barry Warsaw06557452001-12-14 20:47:12 +0000452- Guido's tutorial introduction to the new type/class features has
453 been extensively updated. See
454
455 http://www.python.org/2.2/descrintro.html
456
457 That remains the primary documentation in this area.
458
Guido van Rossum33bab012001-12-05 22:45:48 +0000459- Fixed a leak: instance variables declared with __slots__ were never
460 deleted!
461
Guido van Rossum4b800852001-12-03 00:54:52 +0000462- The "delete attribute" method of descriptor objects is called
463 __delete__, not __del__. In previous releases, it was mistakenly
464 called __del__, which created an unfortunate overloading condition
465 with finalizers. (The "get attribute" and "set attribute" methods
466 are still called __get__ and __set__, respectively.)
467
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000468- Some subtle issues with the super built-in were fixed:
469
470 (a) When super itself is subclassed, its __get__ method would still
471 return an instance of the base class (i.e., of super).
472
473 (b) super(C, C()).__class__ would return C rather than super. This
474 is confusing. To fix this, I decided to change the semantics of
475 super so that it only applies to code attributes, not to data
476 attributes. After all, overriding data attributes is not
477 supported anyway.
478
479 (c) The __get__ method didn't check whether the argument was an
480 instance of the type used in creation of the super instance.
481
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000482- Previously, hash() of an instance of a subclass of a mutable type
483 (list or dictionary) would return some value, rather than raising
484 TypeError. This has been fixed. Also, directly calling
485 dict.__hash__ and list.__hash__ now raises the same TypeError
486 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000487
Guido van Rossumd331cb52001-12-05 19:46:42 +0000488- New-style objects now support deleting their __dict__. This is for
489 all intents and purposes equivalent to assigning a brand new empty
490 dictionary, but saves space if the object is not used further.
491
Tim Petersb3c9af12001-11-17 00:21:57 +0000492Core and builtins
493
Tim Peters3caca232001-12-06 06:23:26 +0000494- -Qnew now works as documented in PEP 238: when -Qnew is passed on
495 the command line, all occurrences of "/" use true division instead
496 of classic division. See the PEP for details. Note that "all"
497 means all instances in library and 3rd-party modules, as well as in
498 your own code. As the PEP says, -Qnew is intended for use only in
499 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000500 Note that test_coercion.py in the standard Python test suite fails
501 under -Qnew; this is expected, and won't be repaired until true
502 division becomes the default (in the meantime, test_coercion is
503 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000504
Fred Drake6c01e252001-12-14 17:08:12 +0000505- complex() now only allows the first argument to be a string
506 argument, and raises TypeError if either the second arg is a string
507 or if the second arg is specified when the first is a string.
508
Tim Petersb3c9af12001-11-17 00:21:57 +0000509Extension modules
510
Martin v. Löwis560da622001-11-24 09:24:51 +0000511- gc.get_referents was renamed to gc.get_referrers.
512
Tim Petersb3c9af12001-11-17 00:21:57 +0000513Library
514
Tim Peters25059d32001-12-07 20:35:43 +0000515- Functions in the os.spawn() family now release the global interpreter
516 lock around calling the platform spawn. They should always have done
517 this, but did not before 2.2c1. Multithreaded programs calling
518 an os.spawn function with P_WAIT will no longer block all Python threads
519 until the spawned program completes. It's possible that some programs
520 relies on blocking, although more likely by accident than by design.
521
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000522- webbrowser defaults to netscape.exe on OS/2 now.
523
Martin v. Löwis652e1912001-11-25 14:50:56 +0000524- Tix.ResizeHandle exposes detach_widget, hide, and show.
525
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000526- The charset alias windows_1252 has been added.
527
Barry Warsaw06557452001-12-14 20:47:12 +0000528- types.StringTypes is a tuple containing the defined string types;
529 usually this will be (str, unicode), but if Python was compiled
530 without Unicode support it will be just (str,).
531
532- The pulldom and minidom modules were synchronized to PyXML.
533
Tim Petersb3c9af12001-11-17 00:21:57 +0000534Tools/Demos
535
Barry Warsaw06557452001-12-14 20:47:12 +0000536- A new script called Tools/scripts/google.py was added, which fires
537 off a search on Google.
538
Tim Petersb3c9af12001-11-17 00:21:57 +0000539Build
540
Barry Warsaw06557452001-12-14 20:47:12 +0000541- Note that release builds of Python should arrange to define the
542 preprocessor symbol NDEBUG on the command line (or equivalent).
543 In the 2.2 pre-release series we tried to define this by magic in
544 Python.h instead, but it proved to cause problems for extension
545 authors. The Unix, Windows and Mac builds now all define NDEBUG in
546 release builds via cmdline (or equivalent) instead. Ports to
547 other platforms should do likewise.
548
Jack Jansen1999ef42001-12-06 21:47:20 +0000549- It is no longer necessary to use --with-suffix when building on a
550 case-insensitive file system (such as Mac OS X HFS+). In the build
551 directory an extension is used, but not in the installed python.
552
Tim Petersb3c9af12001-11-17 00:21:57 +0000553C API
554
Tim Petersf582b822001-12-11 18:51:08 +0000555- New function PyDict_MergeFromSeq2() exposes the builtin dict
556 constructor's logic for updating a dictionary from an iterable object
557 producing key-value pairs.
558
Tim Peterscffed4b2001-11-29 03:26:37 +0000559- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000560 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000561 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
562 dump core in some bad cases. This has been repaired. As a result,
563 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
564 previously went unchallenged.
565
Tim Petersb3c9af12001-11-17 00:21:57 +0000566New platforms
567
568Tests
569
570Windows
571
572Mac
573
Jack Jansenffa260f2001-12-06 21:14:00 +0000574- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
575 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000576
Barry Warsaw06557452001-12-14 20:47:12 +0000577- Changed logic for finding python home in Mac OS X framework Pythons.
578 Now sys.executable points to the executable again, in stead of to
579 the shared library. The latter is used only for locating the python
580 home.
581
582
Tim Peters84362bc2001-10-19 17:55:30 +0000583What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000584Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000585===========================
586
587Type/class unification and new-style classes
588
Guido van Rossum3d27df02001-11-15 20:27:54 +0000589- Multiple inheritance mixing new-style and classic classes in the
590 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000591
592 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000593 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000594
595 The MRO (method resolution order) for each base class is respected
596 according to its kind, but the MRO for the derived class is computed
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000597 using new-style MRO rules if any base class is a new-style class.
Tim Peters76f7fe32001-11-15 20:02:21 +0000598 This needs to be documented.
599
Tim Petersa427a2b2001-10-29 22:25:45 +0000600- The new builtin dictionary() constructor, and dictionary type, have
601 been renamed to dict. This reflects a decade of common usage.
602
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000603- dict() now accepts an iterable object producing 2-sequences. For
604 example, dict(d.items()) == d for any dictionary d. The argument,
605 and the elements of the argument, can be any iterable objects.
606
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000607- New-style classes can now have a __del__ method, which is called
608 when the instance is deleted (just like for classic classes).
609
Guido van Rossum12d955c2001-10-26 14:56:06 +0000610- Assignment to object.__dict__ is now possible, for objects that are
611 instances of new-style classes that have a __dict__ (unless the base
612 class forbids it).
613
Guido van Rossumc8e56452001-10-22 00:43:43 +0000614- Methods of built-in types now properly check for keyword arguments
615 (formerly these were silently ignored). The only built-in methods
616 that take keyword arguments are __call__, __init__ and __new__.
617
Guido van Rossum86443212001-10-27 22:28:54 +0000618- The socket function has been converted to a type; see below.
619
Tim Peters84362bc2001-10-19 17:55:30 +0000620Core and builtins
621
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000622- Assignment to __debug__ raises SyntaxError at compile-time. This
623 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000624 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000625
Guido van Rossum12d955c2001-10-26 14:56:06 +0000626- Clarified the error messages for unsupported operands to an operator
627 (like 1 + '').
628
Tim Peters84362bc2001-10-19 17:55:30 +0000629Extension modules
630
Tim Peters5ebfd362001-11-13 23:11:19 +0000631- mmap has a new keyword argument, "access", allowing a uniform way for
632 both Windows and Unix users to create read-only, write-through and
633 copy-on-write memory mappings. This was previously possible only on
634 Unix. A new keyword argument was required to support this in a
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +0000635 uniform way because the mmap() signatures had diverged across
Tim Peters5ebfd362001-11-13 23:11:19 +0000636 platforms. Thanks to Jay T Miller for repairing this!
637
Tim Peters169ded02001-11-03 19:57:21 +0000638- By default, the gc.garbage list now contains only those instances in
639 unreachable cycles that have __del__ methods; in 2.1 it contained all
640 instances in unreachable cycles. "Instances" here has been generalized
641 to include instances of both new-style and old-style classes.
642
Guido van Rossum12d955c2001-10-26 14:56:06 +0000643- The socket module defines a new method for socket objects,
644 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000645 send() until all data has been sent. Also, the socket function has
646 been converted to a subclassable type, like list and tuple (etc.)
647 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000648
649- Various bugfixes to the curses module. There is now a test suite
650 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000651
Guido van Rossum692adf12001-10-30 03:03:03 +0000652- binascii.b2a_base64 no longer places an arbitrary restriction of 57
653 bytes on its input.
654
Tim Peters84362bc2001-10-19 17:55:30 +0000655Library
656
Tim Peters5ebfd362001-11-13 23:11:19 +0000657- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000658 convenience function.
659
Tim Peters75335872001-11-03 19:35:43 +0000660- Symbolic group names in regular expressions must be unique. For
661 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
662 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000663 Python 2.2 detects this error at regexp compilation time;
664 previously, the error went undetected, and results were
665 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
666 pattern.subn() methods have been rewritten in C. Also, an
667 experimental function/method finditer() has been added, which works
668 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000669
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000670- Tix exposes more commands through the classes DirSelectBox,
671 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
672 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
673 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
674
Tim Peters98791af2001-10-23 01:59:54 +0000675- Traceback objects are now scanned by cyclic garbage collection, so
676 cycles created by casual use of sys.exc_info() no longer cause
677 permanent memory leaks (provided garbage collection is enabled).
678
Guido van Rossum49192142001-10-24 20:51:44 +0000679- os.extsep -- a new variable needed by the RISCOS support. It is the
680 separator used by extensions, and is '.' on all platforms except
681 RISCOS, where it is '/'. There is no need to use this variable
682 unless you have a masochistic desire to port your code to RISCOS.
683
Barry Warsaw012852b2001-11-16 16:17:27 +0000684- mimetypes.py has optional support for non-standard, but commonly
685 found types. guess_type() and guess_extension() now accept an
686 optional `strict' flag, defaulting to true, which controls whether
687 recognize non-standard types or not. A few non-standard types we
688 know about have been added. Also, when run as a script, there are
689 new -l and -e options.
690
691- statcache is now deprecated.
692
693- email.Utils.formatdate() now produces the preferred RFC 2822 style
694 dates with numeric timezones (it used to produce obsolete dates
695 hard coded to "GMT" timezone). An optional `localtime' flag is
696 added to produce dates in the local timezone, with daylight savings
697 time properly taken into account.
698
699- In pickle and cPickle, instead of masking errors in load() by
700 transforming them into SystemError, we let the original exception
701 propagate out. Also, implement support for __safe_for_unpickling__
702 in pickle, as it already was supported in cPickle.
703
Tim Peters84362bc2001-10-19 17:55:30 +0000704Tools/Demos
705
706Build
707
Barry Warsaw012852b2001-11-16 16:17:27 +0000708- The dbm module is built using libdb1 if available. The bsddb module
709 is built with libdb3 if available.
710
711- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
712
Tim Peters84362bc2001-10-19 17:55:30 +0000713C API
714
Tim Peters1fc240e2001-10-26 05:06:50 +0000715- New function PySequence_Fast_GET_SIZE() returns the size of a non-
716 NULL result from PySequence_Fast(), more quickly than calling
717 PySequence_Size().
718
Barry Warsaw012852b2001-11-16 16:17:27 +0000719- New argument unpacking function PyArg_UnpackTuple() added.
720
721- New functions PyObject_CallFunctionObjArgs() and
722 PyObject_CallMethodObjArgs() have been added to make it more
723 convenient and efficient to call functions and methods from C.
724
725- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
726 possible that this will propagate errors it didn't before.
727
728- New function PyObject_CheckReadBuffer(), which returns true if its
729 argument supports the single-segment readable buffer interface.
730
Tim Peters84362bc2001-10-19 17:55:30 +0000731New platforms
732
Guido van Rossum86443212001-10-27 22:28:54 +0000733- We've finally confirmed that this release builds on HP-UX 11.00,
734 *with* threads, and passes the test suite.
735
Tim Peters7a33d8b2001-11-05 02:51:07 +0000736- Thanks to a series of patches from Michael Muller, Python may build
737 again under OS/2 Visual Age C++.
738
Guido van Rossum49192142001-10-24 20:51:44 +0000739- Updated RISCOS port by Dietmar Schwertberger.
740
Tim Peters84362bc2001-10-19 17:55:30 +0000741Tests
742
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000743- Added a test script for the curses module. It isn't run automatically;
744 regrtest.py must be run with '-u curses' to enable it.
745
Tim Peters84362bc2001-10-19 17:55:30 +0000746Windows
747
Barry Warsaw012852b2001-11-16 16:17:27 +0000748Mac
749
750- PythonScript has been moved to unsupported and is slated to be
751 removed completely in the next release.
752
753- It should now be possible to build applets that work on both OS9 and
754 OSX.
755
756- The core is now linked with CoreServices not Carbon; as a side
757 result, default 8bit encoding on OSX is now ASCII.
758
759- Python should now build on OSX 10.1.1
760
Tim Peters84362bc2001-10-19 17:55:30 +0000761
Tim Petersabf925f2001-09-28 21:53:42 +0000762What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000763Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000764===========================
765
766Type/class unification and new-style classes
767
Guido van Rossum687ae002001-10-15 22:03:32 +0000768- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000769 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000770 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000771 remains: the __dict__ of a new-style class is a read-only proxy; you
772 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000773 __defined__ attribute of new-style types no longer exists, for lack
774 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000775 future a __cache__ may be resurrected with a similar function, if I
776 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000777
Tim Peters1c9ca872001-10-04 06:43:12 +0000778- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
779 always returned None, even when there was a class docstring).
780
781- doctest now finds and runs docstrings attached to new-style classes,
782 class methods, static methods, and properties.
783
Guido van Rossum9074ef62001-10-16 21:34:49 +0000784Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000785
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000786- A very subtle syntactical pitfall in list comprehensions was fixed.
787 For example: [a+b for a in 'abc', for b in 'def']. The comma in
788 this example is a mistake. Previously, this would silently let 'a'
789 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
790 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
791 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
792 Note that [a for a in <singleton>] is a convoluted way to say
793 [<singleton>] anyway, so it's not like any expressiveness is lost.
794
Guido van Rossum9074ef62001-10-16 21:34:49 +0000795- getattr(obj, name, default) now only catches AttributeError, as
796 documented, rather than returning the default value for all
797 exceptions (which could mask bugs in a __getattr__ hook, for
798 example).
799
Fred Drakecb7a6b52001-10-22 18:41:51 +0000800- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000801 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000802 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000803 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000804
Guido van Rossum1c486092001-10-19 02:05:35 +0000805- unicode(obj) now behaves more like str(obj), accepting arbitrary
806 objects, and calling a __unicode__ method if it exists.
807 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000808 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000809
Barry Warsawf6fb1712001-10-19 05:35:40 +0000810- isinstance() now allows any object as the first argument and a
811 class, a type or something with a __bases__ tuple attribute for the
812 second argument. The second argument may also be a tuple of a
813 class, type, or something with __bases__, in which case isinstance()
814 will return true if the first argument is an instance of any of the
815 things contained in the second argument tuple. E.g.
816
817 isinstance(x, (A, B))
818
819 returns true if x is an instance of A or B.
820
Guido van Rossum9074ef62001-10-16 21:34:49 +0000821Extension modules
822
823- thread.start_new_thread() now returns the thread ID (previously None).
824
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000825- binascii has now two quopri support functions, a2b_qp and b2a_qp.
826
Guido van Rossumc524d952001-10-19 01:31:59 +0000827- readline now supports setting the startup_hook and the
828 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000829
Guido van Rossumc524d952001-10-19 01:31:59 +0000830- os and posix supports chroot(), setgroups() and unsetenv() where
831 available. The stat(), fstat(), statvfs() and fstatvfs() functions
832 now return "pseudo-sequences" -- the various fields can now be
833 accessed as attributes (e.g. os.stat("/").st_mtime) but for
834 backwards compatibility they also behave as a fixed-length sequence.
835 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000836 attributes.
837
838- time: localtime(), gmtime() and strptime() now return a
839 pseudo-sequence similar to the os.stat() return value, with
840 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000841
Guido van Rossum9074ef62001-10-16 21:34:49 +0000842- Decompression objects in the zlib module now accept an optional
843 second parameter to decompress() that specifies the maximum amount
844 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000845
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000846- optional SSL support in the socket module now exports OpenSSL
847 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
848 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000849 automatically seed its PRNG. Also, the keyfile and certfile
850 arguments to socket.ssl() are now optional.
851
852- posixmodule (and by extension, the os module on POSIX platforms) now
853 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000854
Guido van Rossum9074ef62001-10-16 21:34:49 +0000855Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000856
Tim Peters7402f792001-10-02 03:53:41 +0000857- doctest now excludes functions and classes not defined by the module
858 being tested, thanks to Tim Hochberg.
859
Fred Drakecb7a6b52001-10-22 18:41:51 +0000860- HotShot, a new profiler implemented using a C-based callback, has
861 been added. This substantially reduces the overhead of profiling,
862 but it is still quite preliminary. Support modules and
863 documentation will be added in upcoming releases (before 2.2 final).
864
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000865- profile now produces correct output in situations where an exception
866 raised in Python is cleared by C code (e.g. hasattr()). This used
867 to cause wrong output, including spurious claims of recursive
868 functions and attribution of time spent to the wrong function.
869
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000870 The code and documentation for the derived OldProfile and HotProfile
871 profiling classes was removed. The code hasn't worked for years (if
872 you tried to use them, they raised exceptions). OldProfile
873 intended to reproduce the behavior of the profiler Python used more
874 than 7 years ago, and isn't interesting anymore. HotProfile intended
875 to provide a faster profiler (but producing less information), and
876 that's a worthy goal we intend to meet via a different approach (but
877 without losing information).
878
Tim Peterscce092d2001-10-09 05:31:56 +0000879- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000880 a much better system-specific calibration constant. The constant can
881 now be specified in an instance constructor, or as a Profile class or
882 instance variable, instead of by editing profile.py's source code.
883 Calibration must still be done manually (see the docs for the profile
884 module).
885
886 Note that Profile.calibrate() must be overriden by subclasses.
887 Improving the accuracy required exploiting detailed knowledge of
888 profiler internals; the earlier method abstracted away the details
889 and measured a simplified model instead, but consequently computed
890 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000891
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000892- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000893 which indicates whether output is intended for the header 'Q'
894 encoding.
895
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000896- The SocketServer.ThreadingMixIn class now closes the request after
897 finish_request() returns. (Not when it errors out though.)
898
Barry Warsawf6fb1712001-10-19 05:35:40 +0000899- The nntplib module's NNTP.body() method has grown a `file' argument
900 to allow saving the message body to a file.
901
902- The email package has added a class email.Parser.HeaderParser which
903 only parses headers and does not recurse into the message's body.
904 Also, the module/class MIMEAudio has been added for representing
905 audio data (contributed by Anthony Baxter).
906
907- ftplib should be able to handle files > 2GB.
908
909- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
910 ON, and OFF.
911
Fred Drakecb7a6b52001-10-22 18:41:51 +0000912- xml.dom.minidom NodeList objects now support the length attribute
913 and item() method as required by the DOM specifications.
914
Guido van Rossumed554f62001-10-02 23:15:37 +0000915Tools/Demos
916
917- Demo/dns was removed. It no longer serves any purpose; a package
918 derived from it is now maintained by Anthony Baxter, see
919 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000920
Barry Warsawf6fb1712001-10-19 05:35:40 +0000921- The freeze tool has been made more robust, and two new options have
922 been added: -X and -E.
923
Tim Petersabf925f2001-09-28 21:53:42 +0000924Build
925
Barry Warsawf6fb1712001-10-19 05:35:40 +0000926- configure will use CXX in LINKCC if CXX is used to build main() and
927 the system requires to link a C++ main using the C++ compiler.
928
Tim Petersabf925f2001-09-28 21:53:42 +0000929C API
930
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000931- The documentation for the tp_compare slot is updated to require that
932 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
933 not correct. This is not yet enforced but will be enforced in
934 Python 2.3; even later, we may use -2 to indicate errors and +2 for
935 "NotImplemented". Right now, -1 should be used for an error return.
936
Tim Petersd38b1c72001-09-30 05:09:37 +0000937- PyLong_AsLongLong() now accepts int (as well as long) arguments.
938 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
939 as long) arguments.
940
Guido van Rossum3c288632001-10-16 21:13:49 +0000941- PyThread_start_new_thread() now returns a long int giving the thread
942 ID, if one can be calculated; it returns -1 for error, 0 if no
943 thread ID is calculated (this is an incompatible change, but only
944 the thread module used this API). This code has only really been
945 tested on Linux and Windows; other platforms please beware (and
946 report any bugs or strange behavior).
947
Guido van Rossum1c486092001-10-19 02:05:35 +0000948- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
949 input.
950
Tim Petersabf925f2001-09-28 21:53:42 +0000951New platforms
952
953Tests
954
955Windows
956
Tim Peters04cf1d32001-10-09 22:39:40 +0000957- Installer: If you install IDLE, and don't disable file-extension
958 registration, a new "Edit with IDLE" context (right-click) menu entry
959 is created for .py and .pyw files.
960
Tim Peters1ce3cf72001-10-01 17:58:40 +0000961- The signal module now supports SIGBREAK on Windows, thanks to Steven
962 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
963 action remains to call Win32 ExitProcess(). This can be changed via
964 signal.signal(). For example:
965
966 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
967 # (SIGINT) behavior.
968 import signal
969 signal.signal(signal.SIGBREAK,
970 signal.default_int_handler)
971
972 try:
973 while 1:
974 pass
975 except KeyboardInterrupt:
976 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
977 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
978 # program without the possibility for any Python-level cleanup).
979 print "Clean exit"
980
Tim Petersabf925f2001-09-28 21:53:42 +0000981
Tim Petersb07352e2001-09-08 01:25:47 +0000982What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000983Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000984===========================
985
Guido van Rossum808eea72001-09-25 04:15:41 +0000986Type/class unification and new-style classes
987
988- pydoc and inspect are now aware of new-style classes;
989 e.g. help(list) at the interactive prompt now shows proper
990 documentation for all operations on list objects.
991
992- Applications using Jim Fulton's ExtensionClass module can now safely
993 be used with Python 2.2. In particular, Zope 2.4.1 now works with
994 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
995 examples also work again. It is hoped that Gtk and Boost also work
996 with 2.2a4 and beyond. (If you can confirm this, please write
997 webmaster@python.org; if there are still problems, please open a bug
998 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000999
Tim Peters66c1a522001-09-24 21:17:50 +00001000- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001001 These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
Tim Peters66c1a522001-09-24 21:17:50 +00001002 in the constructed property object. fget, fset and fdel weren't
1003 discoverable from Python in 2.2a3. __doc__ is new, and allows to
1004 associate a docstring with a property.
1005
Guido van Rossum808eea72001-09-25 04:15:41 +00001006- Comparison overloading is now more completely implemented. For
1007 example, a str subclass instance can properly be compared to a str
1008 instance, and it can properly overload comparison. Ditto for most
1009 other built-in object types.
1010
1011- The repr() of new-style classes has changed; instead of <type
1012 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
1013 *except* for built-in types, which are still rendered as <type
1014 'Foo'> (to avoid upsetting existing code that might parse or
1015 otherwise rely on repr() of certain type objects).
1016
1017- The repr() of new-style objects is now always <Foo object at XXX>;
1018 previously, it was sometimes <Foo instance at XXX>.
1019
1020- For new-style classes, what was previously called __getattr__ is now
1021 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001022 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +00001023 one in classic classes is defined which is called only if regular
1024 attribute access raises AttributeError; to catch *all* attribute
1025 access, you can use __getattribute__ (for new-style classes). If
1026 both are defined, __getattribute__ is called first, and if it raises
1027 AttributeError, __getattr__ is called.
1028
1029- The __class__ attribute of new-style objects can be assigned to.
1030 The new class must have the same C-level object layout as the old
1031 class.
1032
1033- The builtin file type can be subclassed now. In the usual pattern,
1034 "file" is the name of the builtin type, and file() is a new builtin
1035 constructor, with the same signature as the builtin open() function.
1036 file() is now the preferred way to open a file.
1037
1038- Previously, __new__ would only see sequential arguments passed to
1039 the type in a constructor call; __init__ would see both sequential
1040 and keyword arguments. This made no sense whatsoever any more, so
1041 now both __new__ and __init__ see all arguments.
1042
1043- Previously, hash() applied to an instance of a subclass of str or
1044 unicode always returned 0. This has been repaired.
1045
1046- Previously, an operation on an instance of a subclass of an
1047 immutable type (int, long, float, complex, tuple, str, unicode),
1048 where the subtype didn't override the operation (and so the
1049 operation was handled by the builtin type), could return that
1050 instance instead a value of the base type. For example, if s was of
Andrew M. Kuchling21b23b02002-05-07 20:58:03 +00001051 a str subclass type, s[:] returned s as-is. Now it returns a str
Guido van Rossum808eea72001-09-25 04:15:41 +00001052 with the same value as s.
1053
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001054- Provisional support for pickling new-style objects has been added.
1055
Guido van Rossum808eea72001-09-25 04:15:41 +00001056Core
1057
Tim Peters2c9aa5e2001-09-23 04:06:05 +00001058- file.writelines() now accepts any iterable object producing strings.
1059
Marc-André Lemburgaefd7662001-09-20 12:59:37 +00001060- PyUnicode_FromEncodedObject() now works very much like
1061 PyObject_Str(obj) in that it tries to use __str__/tp_str
1062 on the object if the object is not a string or buffer. This
1063 makes unicode() behave like str() when applied to non-string/buffer
1064 objects.
1065
Andrew M. Kuchling51c18162001-10-22 01:47:26 +00001066- PyFile_WriteObject now passes Unicode objects to the file's write
1067 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +00001068 of a print statement must support Unicode objects, i.e. they must
1069 at least convert them into ASCII strings.
1070
Guido van Rossum624c8af2001-09-18 15:21:04 +00001071- Thread scheduling on Solaris should be improved; it is no longer
1072 necessary to insert a small sleep at the start of a thread in order
1073 to let other runnable threads be scheduled.
1074
Tim Petersb07352e2001-09-08 01:25:47 +00001075Library
1076
Marc-André Lemburgbf990172001-09-27 14:17:33 +00001077- StringIO.StringIO instances and cStringIO.StringIO instances support
1078 read character buffer compatible objects for their .write() methods.
1079 These objects are converted to strings and then handled as such
1080 by the instances.
1081
Barry Warsaw2f600732001-09-24 04:28:10 +00001082- The "email" package has been added. This is basically a port of the
1083 mimelib package <http://sf.net/projects/mimelib> with API changes
1084 and some implementations updated to use iterators and generators.
1085
Tim Peters8a9c2842001-09-22 21:30:22 +00001086- difflib.ndiff() and difflib.Differ.compare() are generators now. This
1087 restores the ability of Tools/scripts/ndiff.py to start producing output
1088 before the entire comparison is complete.
1089
Barry Warsaw58b072d2001-09-22 04:44:21 +00001090- StringIO.StringIO instances and cStringIO.StringIO instances support
1091 iteration just like file objects (i.e. their .readline() method is
1092 called for each iteration until it returns an empty string).
1093
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +00001094- The codecs module has grown four new helper APIs to access
1095 builtin codecs: getencoder(), getdecoder(), getreader(),
1096 getwriter().
1097
Guido van Rossum624c8af2001-09-18 15:21:04 +00001098- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
1099 simplifies writing XML RPC servers.
1100
Barry Warsaw647d5e82001-09-28 17:01:02 +00001101- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +00001102 after interpretation of symbolic links. On non-Unix systems, this
1103 is an alias for os.path.abspath().
1104
Tim Peters16a77ad2001-09-08 04:00:12 +00001105- operator.indexOf() (PySequence_Index() in the C API) now works with any
1106 iterable object.
1107
Guido van Rossum624c8af2001-09-18 15:21:04 +00001108- smtplib now supports various authentication and security features of
1109 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001110
Guido van Rossum624c8af2001-09-18 15:21:04 +00001111- hmac: a new module implementing keyed hashing for message
1112 authentication.
1113
1114- mimetypes now recognizes more extensions and file types. At the
1115 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +00001116
Guido van Rossum624c8af2001-09-18 15:21:04 +00001117- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001118 Python 2.2 bytecode generation. It has also been promoted from a
1119 Tool to a standard library package. (Tools/compiler still exists as
1120 a sample driver.)
1121
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +00001122Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +00001123
Tim Petersb07352e2001-09-08 01:25:47 +00001124Build
1125
Guido van Rossum624c8af2001-09-18 15:21:04 +00001126- Large file support (LFS) is now automatic when the platform supports
1127 it; no more manual configuration tweaks are needed. On Linux, at
1128 least, it's possible to have a system whose C library supports large
1129 files but whose kernel doesn't; in this case, large file support is
1130 still enabled but doesn't do you any good unless you upgrade your
1131 kernel or share your Python executable with another system whose
1132 kernel has large file support.
1133
1134- The configure script now supplies plausible defaults in a
1135 cross-compilation environment. This doesn't mean that the supplied
1136 values are always correct, or that cross-compilation now works
1137 flawlessly -- but it's a first step (and it shuts up most of
1138 autoconf's warnings about AC_TRY_RUN).
1139
1140- The Unix build is now a bit less chatty, courtesy of the parser
1141 generator. The build is completely silent (except for errors) when
1142 using "make -s", thanks to a -q option to setup.py.
1143
Tim Petersb07352e2001-09-08 01:25:47 +00001144C API
1145
Guido van Rossum624c8af2001-09-18 15:21:04 +00001146- The "structmember" API now supports some new flag bits to deny read
1147 and/or write access to attributes in restricted execution mode.
1148
Tim Petersb07352e2001-09-08 01:25:47 +00001149New platforms
1150
Guido van Rossum624c8af2001-09-18 15:21:04 +00001151- Compaq's iPAQ handheld, running the "familiar" Linux distribution
1152 (http://familiar.handhelds.org).
1153
Tim Petersb07352e2001-09-08 01:25:47 +00001154Tests
1155
Tim Peters8a9c2842001-09-22 21:30:22 +00001156- The "classic" standard tests, which work by comparing stdout to
1157 an expected-output file under Lib/test/output/, no longer stop at
1158 the first mismatch. Instead the test is run to completion, and a
1159 variant of ndiff-style comparison is used to report all differences.
1160 This is much easier to understand than the previous style of reporting.
1161
1162- The unittest-based standard tests now use regrtest's test_main()
1163 convention, instead of running as a side-effect of merely being
1164 imported. This allows these tests to be run in more natural and
1165 flexible ways as unittests, outside the regrtest framework.
1166
1167- regrtest.py is much better integrated with unittest and doctest now,
1168 especially in regard to reporting errors.
1169
Tim Petersb07352e2001-09-08 01:25:47 +00001170Windows
1171
Guido van Rossum624c8af2001-09-18 15:21:04 +00001172- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001173 that support it (NTFS under Windows 2000). See "What's New in
1174 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001175
Tim Petersb07352e2001-09-08 01:25:47 +00001176
Tim Petersedc99312001-08-22 21:36:50 +00001177What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001178Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001179===========================
1180
1181Core
1182
Tim Peters9fffa3e2001-09-04 05:14:19 +00001183- Conversion of long to float now raises OverflowError if the long is too
1184 big to represent as a C double.
1185
Tim Peters32f453e2001-09-03 08:35:41 +00001186- The 3-argument builtin pow() no longer allows a third non-None argument
1187 if either of the first two arguments is a float, or if both are of
1188 integer types and the second argument is negative (in which latter case
1189 the arguments are converted to float, so this is really the same
1190 restriction).
1191
Tim Peters5d2b77c2001-09-03 05:47:38 +00001192- The builtin dir() now returns more information, and sometimes much
1193 more, generally naming all attributes of an object, and all attributes
1194 reachable from the object via its class, and from its class's base
1195 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1196 an empty list. In 2.2a3,
1197
1198 >>> dir([])
1199 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1200 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1201 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1202 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1203 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1204 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1205 'reverse', 'sort']
1206
1207 dir(module) continues to return only the module's attributes, though.
1208
Tim Petersbdee63f2001-09-02 03:40:59 +00001209- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001210 than raising OverflowError. This is a partial implementation of PEP
1211 237. You can use -Wdefault::OverflowWarning to enable a warning for
1212 this situation, and -Werror::OverflowWarning to revert to the old
1213 OverflowError exception.
1214
Guido van Rossum61c345f2001-09-04 03:26:15 +00001215- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001216 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001217 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1218 -Qold, meaning the / operator has its classic meaning and no
1219 warnings are issued. Using -Qwarn issues a run-time warning about
1220 all uses of classic division for int and long arguments; -Qwarnall
1221 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001222 (for use with fixdiv.py).
1223 [Note: the remainder of this paragraph (preserved below) became
1224 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1225 <obsolete>
1226 Using -Qnew is questionable; it turns on new division by default, but
1227 only in the __main__ module. You can usefully combine -Qwarn or
1228 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1229 warns about classic division everywhere else.
1230 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001231
Tim Petersbdee63f2001-09-02 03:40:59 +00001232- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001233 long, float, str, unicode, and tuple. (The types complex, list and
1234 dictionary can also be subclassed; this was introduced earlier.)
1235 Note that restrictions apply when subclassing immutable built-in
1236 types: you can only affect the value of the instance by overloading
1237 __new__. You can add mutable attributes, and the subclass instances
1238 will have a __dict__ attribute, but you cannot change the "value"
1239 (as implemented by the base class) of an immutable subclass instance
1240 once it is created.
1241
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001242- The dictionary constructor now takes an optional argument, a
1243 mapping-like object, and initializes the dictionary from its
1244 (key, value) pairs.
1245
Tim Petersbdee63f2001-09-02 03:40:59 +00001246- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001247 "cooperative super calls" in a multiple inheritance setting. For an
1248 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1249
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001250- A new built-in type, property, has been added. This enables the
1251 creation of "properties". These are attributes implemented by
1252 getter and setter functions (or only one of these for read-only or
1253 write-only attributes), without the need to override __getattr__.
1254 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001255
Tim Petersbdee63f2001-09-02 03:40:59 +00001256- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001257 liberalized, to allow leading zeroes. Examples of literals now
1258 legal that were SyntaxErrors before:
1259
1260 00.0 0e3 0100j 07.5 00000000000000000008.
1261
Tim Petersbdee63f2001-09-02 03:40:59 +00001262- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001263 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1264
Tim Petersedc99312001-08-22 21:36:50 +00001265Library
1266
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001267- telnetlib includes symbolic names for the options, and support for
1268 setting an option negotiation callback.
1269
Tim Petersa40c7932001-09-05 22:36:56 +00001270- The new C standard no longer requires that math libraries set errno to
1271 ERANGE on overflow. For platform libraries that exploit this new
1272 freedom, Python's overflow-checking was wholly broken. A new overflow-
1273 checking scheme attempts to repair that, but may not be reliable on all
1274 platforms (C doesn't seem to provide anything both useful and portable
1275 in this area anymore).
1276
Martin v. Löwis44f86962001-09-05 13:44:54 +00001277- Asynchronous timeout actions are available through the new class
1278 threading.Timer.
1279
Tim Peters78526162001-09-05 00:53:45 +00001280- math.log and math.log10 now return sensible results for even huge
1281 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1282
Tim Petersbdee63f2001-09-02 03:40:59 +00001283- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001284 currently held. See the docs for the imp module.
1285
Tim Petersbdee63f2001-09-02 03:40:59 +00001286- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001287 dumps containing ints written on platforms where Python ints are 8 bytes.
1288 When read on a box where Python ints are 4 bytes, such values are
1289 converted to Python longs.
1290
Tim Petersbdee63f2001-09-02 03:40:59 +00001291- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001292 code objects is no longer allowed. This plugs a security hole.
1293
Steve Purcell6091cd62001-09-06 16:05:17 +00001294- unittest.TestResult instances no longer store references to tracebacks
1295 generated by test failures. This prevents unexpected dangling references
1296 to objects that should be garbage collected between tests.
1297
Tim Petersedc99312001-08-22 21:36:50 +00001298Tools
1299
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001300- Tools/scripts/fixdiv.py has been added which can be used to fix
1301 division operators as per PEP 238.
1302
Tim Petersedc99312001-08-22 21:36:50 +00001303Build
1304
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001305- If you are an adventurous person using Mac OS X you may want to look at
1306 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1307 application, which can be used for experimenting with Carbon or Cocoa.
1308 Discussion of this on pythonmac-sig, please.
1309
Tim Peters7eea37e2001-09-04 22:08:56 +00001310C API
1311
1312- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001313
Tim Peters9fffa3e2001-09-04 05:14:19 +00001314- Note that PyLong_AsDouble can fail! This has always been true, but no
1315 callers checked for it. It's more likely to fail now, because overflow
1316 errors are properly detected now. The proper way to check:
1317
1318 double x = PyLong_AsDouble(some_long_object);
1319 if (x == -1.0 && PyErr_Occurred()) {
1320 /* The conversion failed. */
1321 }
1322
Tim Petersbdee63f2001-09-02 03:40:59 +00001323- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001324 compile but will not participate in GC. To upgrade an extension
1325 module:
1326
1327 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001328
Neil Schemenauer4042c692001-08-30 15:38:01 +00001329 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1330 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001331
Neil Schemenauer4042c692001-08-30 15:38:01 +00001332 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1333 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001334
Neil Schemenauer4042c692001-08-30 15:38:01 +00001335 - remove PyGC_HEAD_SIZE from object size calculations
1336
1337 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1338
Tim Petersbdee63f2001-09-02 03:40:59 +00001339- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001340 These can be used safely to construct string objects from a
1341 sprintf-style format string (similar to the format string supported
1342 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001343
Tim Petersedc99312001-08-22 21:36:50 +00001344New platforms
1345
Tim Petersb7da0902001-09-02 23:01:43 +00001346- Stephen Hansen contributed patches sufficient to get a clean compile
1347 under Borland C (Windows), but he reports problems running it and ran
1348 out of time to complete the port. Volunteers? Expect a MemoryError
1349 when importing the types module; this is probably shallow, and
1350 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001351
Tim Petersedc99312001-08-22 21:36:50 +00001352Tests
1353
1354Windows
1355
Tim Peters6e13a562001-09-06 00:32:15 +00001356- Large file support is now enabled on Win32 platforms as well as on
1357 Win64. This means that, for example, you can use f.tell() and f.seek()
1358 to manipulate files larger than 2 gigabytes (provided you have enough
1359 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001360 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1361 filesize limit, and large file support makes no difference there.
1362 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1363 NTFS has no practical limit on file size, and files of any size can be
1364 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001365
Tim Petersbdee63f2001-09-02 03:40:59 +00001366- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001367 points to command.com (patch from Brian Quinlan).
1368
Tim Petersedc99312001-08-22 21:36:50 +00001369
Tim Peters20f51a72001-07-21 02:31:40 +00001370What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001371Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001372===========================
1373
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001374Build
1375
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001376- Tim Peters developed a brand new Windows installer using Wise 8.1,
1377 generously donated to us by Wise Solutions.
1378
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001379- configure supports a new option --enable-unicode, with the values
1380 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1381 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001382
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001383- A new configure option --enable-framework builds a Mac OS X framework,
1384 which "make frameworkinstall" will install. This provides a starting
1385 point for more mac-like functionality, join pythonmac-sig@python.org
1386 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001387
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001388- The NeXT platform is no longer supported.
1389
1390- The `new' module is now statically linked.
1391
Tim Peters0afb6092001-08-15 06:06:44 +00001392Tools
1393
1394- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001395 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001396 the module docstring for details.
1397
Tim Peters20f51a72001-07-21 02:31:40 +00001398Tests
1399
Tim Peters5e824c32001-08-12 22:25:01 +00001400- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001401 platforms, allowing to give clearer test result output. regrtest
1402 also has optional --use/-u switch to run normally disabled tests
1403 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001404
Tim Peters20f51a72001-07-21 02:31:40 +00001405- Several new tests in the standard test suite, with special thanks to
1406 Nick Mathewson.
1407
1408Core
1409
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001410- The floor division operator // has been added as outlined in PEP
1411 238. The / operator still provides classic division (and will until
1412 Python 3.0) unless "from __future__ import division" is included, in
1413 which case the / operator will provide true division. The operator
1414 module provides truediv() and floordiv() functions. Augmented
1415 assignment variants are included, as are the equivalent overloadable
1416 methods and C API methods. See the PEP for a full discussion:
1417 <http://python.sf.net/peps/pep-0238.html>
1418
Tim Peters6cd6a822001-08-17 22:11:27 +00001419- Future statements are now effective in simulated interactive shells
1420 (like IDLE). This should "just work" by magic, but read Michael
1421 Hudson's "Future statements in simulated shells" PEP 264 for full
1422 details: <http://python.sf.net/peps/pep-0264.html>.
1423
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001424- The type/class unification (PEP 252-253) was integrated into the
1425 trunk and is not so tentative any more (the exact specification of
1426 some features is still tentative). A lot of work has done on fixing
1427 bugs and adding robustness and features (performance still has to
1428 come a long way).
1429
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001430- Warnings about a mismatch in the Python API during extension import
1431 now use the Python warning framework (which makes it possible to
1432 write filters for these warnings).
1433
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001434- A function's __dict__ (aka func_dict) will now always be a
1435 dictionary. It used to be possible to delete it or set it to None,
1436 but now both actions raise TypeErrors. It is still legal to set it
1437 to a dictionary object. Getting func.__dict__ before any attributes
1438 have been assigned now returns an empty dictionary instead of None.
1439
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001440- A new command line option, -E, was added which disables the use of
1441 all environment variables, or at least those that are specifically
1442 significant to Python. Usually those have a name starting with
1443 "PYTHON". This was used to fix a problem where the tests fail if
1444 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1445 older distribution.
1446
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001447Library
1448
Tim Peters5e824c32001-08-12 22:25:01 +00001449- New class Differ and new functions ndiff() and restore() in difflib.py.
1450 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001451 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001452
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001453- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1454 value using the minimal quoting required for the value; more
1455 reliable than using xml.sax.saxutils.escape() for attribute values.
1456
1457- Readline completion support for cmd.Cmd was added.
1458
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001459- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1460
1461- Added function threading.BoundedSemaphore()
1462
1463- Added Ka-Ping Yee's cgitb.py module.
1464
1465- The `new' module now exposes the CO_xxx flags.
1466
Martin v. Löwis560da622001-11-24 09:24:51 +00001467- The gc module offers the get_referents function.
1468
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001469New platforms
1470
1471C API
1472
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001473- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1474 which provide a cross-platform implementations for the
1475 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1476 the standard sprintf() and vsprintf() C lib APIs, these versions
1477 apply bounds checking on the used buffer which enhances protection
1478 against buffer overruns.
1479
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001480- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001481 and extensions using different Unicode widths is rendered next to
1482 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001483 will result in an ImportError. Unicode extensions writers must make
1484 sure to check the Unicode width compatibility in their extensions by
1485 using at least one of the mangled Unicode APIs in the extension.
1486
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001487- Two new flags METH_NOARGS and METH_O are available in method definition
1488 tables to simplify implementation of methods with no arguments and a
1489 single untyped argument. Calling such methods is more efficient than
1490 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1491 deprecated.
1492
Tim Petersc1731372001-08-04 08:12:36 +00001493Windows
1494
1495- "import module" now compiles module.pyw if it exists and nothing else
1496 relevant is found.
1497
Tim Peters20f51a72001-07-21 02:31:40 +00001498
Guido van Rossum55a78992001-07-17 17:22:32 +00001499What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001500Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001501===========================
1502
1503Core
Tim Petersa814db52001-05-14 07:05:58 +00001504
Tim Peters6d6c1a32001-08-02 04:15:00 +00001505- TENTATIVELY, a large amount of code implementing much of what's
1506 described in PEP 252 (Making Types Look More Like Classes) and PEP
1507 253 (Subtyping Built-in Types) was added. This will be released
1508 with Python 2.2a1. Documentation will be provided separately
1509 through http://www.python.org/2.2/. The purpose of releasing this
1510 with Python 2.2a1 is to test backwards compatibility. It is
1511 possible, though not likely, that a decision is made not to release
1512 this code as part of 2.2 final, if any serious backwards
1513 incompapatibilities are found during alpha testing that cannot be
1514 repaired.
1515
Guido van Rossum55a78992001-07-17 17:22:32 +00001516- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001517 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001518 more 'yield' statements. See PEP 255. Since this adds a new
1519 keyword to the language, this feature must be enabled by including a
1520 future statement: "from __future__ import generators" (see PEP 236).
1521 Generators will become a standard feature in a future release
1522 (probably 2.3). Without this future statement, 'yield' remains an
1523 ordinary identifier, but a warning is issued each time it is used.
1524 (These warnings currently don't conform to the warnings framework of
1525 PEP 230; we intend to fix this in 2.2a2.)
1526
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001527- The UTF-16 codec was modified to be more RFC compliant. It will now
1528 only remove BOM characters at the start of the string and then
1529 only if running in native mode (UTF-16-LE and -BE won't remove a
1530 leading BMO character).
1531
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001532- Strings now have a new method .decode() to complement the already
1533 existing .encode() method. These two methods provide direct access
1534 to the corresponding decoders and encoders of the registered codecs.
1535
1536 To enhance the usability of the .encode() method, the special
1537 casing of Unicode object return values was dropped (Unicode objects
1538 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001539
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001540 Both methods will now return whatever the codec in charge of the
1541 requested encoding returns as object, e.g. Unicode codecs will
1542 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1543 will return u"äöü"). This enables codec writer to create codecs
1544 for various simple to use conversions.
1545
1546 New codecs were added to demonstrate these new features (the .encode()
1547 and .decode() columns indicate the type of the returned objects):
1548
1549 Name | .encode() | .decode() | Description
1550 ----------------------------------------------------------------------
1551 uu | string | string | UU codec (e.g. for email)
1552 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001553 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001554 zlib | string | string | zlib compression
1555 hex | string | string | 2-byte hex codec
1556 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1557
Mark Hammond2a0af792001-05-14 03:09:36 +00001558- Some operating systems now support the concept of a default Unicode
1559 encoding for file system operations. Notably, Windows supports 'mbcs'
1560 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001561 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001562 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001563
1564 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001565 functions that return filenames (such as os.listdir()) to return Python
1566 string objects pre-encoded using the default file system encoding for
1567 the platform. As this encoding is likely to be different from Python's
1568 default encoding, converting this name to a Unicode object before passing
1569 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001570 would attempt to use its default encoding (generally ASCII) rather than
1571 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001572
Tim Petersa814db52001-05-14 07:05:58 +00001573 In general, this change simply removes surprises when working with
1574 Unicode and the file system, making these operations work as you expect,
1575 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001576 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001577
Tim Peters61dff2b2001-05-08 15:43:37 +00001578- Float (and complex) literals in source code were evaluated to full
1579 precision only when running from a .py file; the same code loaded from a
1580 .pyc (or .pyo) file could suffer numeric differences starting at about the
1581 12th significant decimal digit. For example, on a machine with IEEE-754
1582 floating arithmetic,
1583
1584 x = 9007199254740992.0
1585 print long(x)
1586
1587 printed 9007199254740992 if run directly from .py, but 9007199254740000
1588 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1589 str(float) instead of repr(float) when building code objects. marshal
1590 now uses repr(float) instead, which should reproduce floats to full
1591 machine precision (assuming the platform C float<->string I/O conversion
1592 functions are of good quality).
1593
1594 This may cause floating-point results to change in some cases, and
1595 usually for the better, but may also cause numerically unstable
1596 algorithms to break.
1597
Tim Peters2f228e72001-05-13 00:19:31 +00001598- The implementation of dicts suffers fewer collisions, which has speed
1599 benefits. However, the order in which dict entries appear in dict.keys(),
1600 dict.values() and dict.items() may differ from previous releases for a
1601 given dict. Nothing is defined about this order, so no program should
1602 rely on it. Nevertheless, it's easy to write test cases that rely on the
1603 order by accident, typically because of printing the str() or repr() of a
1604 dict to an "expected results" file. See Lib/test/test_support.py's new
1605 sortdict(dict) function for a simple way to display a dict in sorted
1606 order.
1607
Tim Peters7a3bfc32001-06-12 01:22:22 +00001608- Many other small changes to dicts were made, resulting in faster
1609 operation along the most common code paths.
1610
Guido van Rossum10315822001-05-01 20:54:30 +00001611- Dictionary objects now support the "in" operator: "x in dict" means
1612 the same as dict.has_key(x).
1613
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001614- The update() method of dictionaries now accepts generic mapping
1615 objects. Specifically the argument object must support the .keys()
1616 and __getitem__() methods. This allows you to say, for example,
1617 {}.update(UserDict())
1618
Guido van Rossum10315822001-05-01 20:54:30 +00001619- Iterators were added; this is a generalized way of providing values
1620 to a for loop. See PEP 234. There's a new built-in function iter()
1621 to return an iterator. There's a new protocol to get the next value
1622 from an iterator using the next() method (in Python) or the
1623 tp_iternext slot (in C). There's a new protocol to get iterators
1624 using the __iter__() method (in Python) or the tp_iter slot (in C).
1625 Iterating (i.e. a for loop) over a dictionary generates its keys.
1626 Iterating over a file generates its lines.
1627
Tim Petersf553f892001-05-01 20:45:31 +00001628- The following functions were generalized to work nicely with iterator
1629 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001630 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001631 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1632 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001633 join() method of strings
1634 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001635 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1636 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001637 right-hand side of assignment statements with multiple targets, such as
1638 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001639
Tim Petersd85e1022001-05-11 21:51:48 +00001640- Accessing module attributes is significantly faster (for example,
1641 random.random or os.path or yourPythonModule.yourAttribute).
1642
Tim Peterse63415e2001-05-08 04:38:29 +00001643- Comparing dictionary objects via == and != is faster, and now works even
1644 if the keys and values don't support comparisons other than ==.
1645
Tim Peters95bf9392001-05-10 08:32:44 +00001646- Comparing dictionaries in ways other than == and != is slower: there were
1647 insecurities in the dict comparison implementation that could cause Python
1648 to crash if the element comparison routines for the dict keys and/or
1649 values mutated the dicts. Making the code bulletproof slowed it down.
1650
Tim Peterseb28ef22001-06-02 05:27:19 +00001651- Collisions in dicts are resolved via a new approach, which can help
1652 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001653 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001654 faster now. Thanks to Christian Tismer for pointing out the cause and
1655 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001656
Tim Peters52e155e2001-06-16 05:42:57 +00001657- repr() is much faster for large containers (dict, list, tuple).
1658
1659
Tim Petersa814db52001-05-14 07:05:58 +00001660Library
1661
Fred Drake960fdf92001-07-20 18:38:26 +00001662- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1663 were added to the string module. These a locale-indenpendent
1664 constants, unlike letters, lowercase, and uppercase. These are now
1665 use in appropriate locations in the standard library.
1666
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001667- The flags used in dlopen calls can now be configured using
1668 sys.setdlopenflags and queried using sys.getdlopenflags.
1669
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001670- Fredrik Lundh's xmlrpclib is now a standard library module. This
1671 provides full client-side XML-RPC support. In addition,
1672 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1673 one asyncore-based). Thanks to Eric Raymond for the documentation.
1674
Guido van Rossum643d3912001-07-05 14:46:25 +00001675- The xrange() object is simplified: it no longer supports slicing,
1676 repetition, comparisons, efficient 'in' checking, the tolist()
1677 method, or the start, stop and step attributes. See PEP 260.
1678
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001679- A new function fnmatch.filter to filter lists of file names was added.
1680
Barry Warsawffd674d2001-05-22 16:00:10 +00001681- calendar.py uses month and day names based on the current locale.
1682
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001683- strop is now *really* obsolete (this was announced before with 1.6),
1684 and issues DeprecationWarning when used (except for the four items
1685 that are still imported into string.py).
1686
Tim Petersa814db52001-05-14 07:05:58 +00001687- Cookie.py now sorts key+value pairs by key in output strings.
1688
1689- pprint.isrecursive(object) didn't correctly identify recursive objects.
1690 Now it does.
1691
Tim Peters95b3f782001-05-14 18:39:41 +00001692- pprint functions now much faster for large containers (tuple, list, dict).
1693
Tim Peters7b9542a2001-06-10 23:40:19 +00001694- New 'q' and 'Q' format codes in the struct module, corresponding to C
1695 types "long long" and "unsigned long long" (on Windows, __int64). In
1696 native mode, these can be used only when the platform C compiler supports
1697 these types (when HAVE_LONG_LONG is #define'd by the Python config
1698 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001699 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1700 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001701
Guido van Rossum83213cc2001-06-12 16:48:52 +00001702- The site module installs a new built-in function 'help' that invokes
1703 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1704 it displays a message reminding the user to use 'help()' or
1705 'help(object)'.
1706
Tim Petersa814db52001-05-14 07:05:58 +00001707Tests
1708
1709- New test_mutants.py runs dict comparisons where the key and value
1710 comparison operators mutute the dicts randomly during comparison. This
1711 rapidly causes Python to crash under earlier releases (not for the faint
1712 of heart: it can also cause Win9x to freeze or reboot!).
1713
1714- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001715 pprint.isreadable() return sensible results. Also verifies that simple
1716 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001717
Tim Peters4324aa32001-05-28 22:30:08 +00001718C API
1719
1720- Removed the unused last_is_sticky argument from the internal
1721 _PyTuple_Resize(). If this affects you, you were cheating.
1722
1723
Guido van Rossum55a78992001-07-17 17:22:32 +00001724======================================================================
1725
1726
Guido van Rossumffe13be2001-04-16 18:46:45 +00001727What's New in Python 2.1 (final)?
1728=================================
1729
1730We only changed a few things since the last release candidate, all in
1731Python library code:
1732
1733- A bug in the locale module was fixed that affected locales which
1734 define no grouping for numeric formatting.
1735
1736- A few bugs in the weakref module's implementations of weak
1737 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1738 and the test suite was updated to check for these bugs.
1739
1740- An old bug in the os.path.walk() function (introduced in Python
1741 2.0!) was fixed: a non-existent file would cause an exception
1742 instead of being ignored.
1743
1744- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1745 PyChecker.
1746
1747
Guido van Rossum5b08f132001-04-16 02:05:23 +00001748What's New in Python 2.1c2?
1749===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001750
Guido van Rossum5b08f132001-04-16 02:05:23 +00001751A flurry of small changes, and one showstopper fixed in the nick of
1752time made it necessary to release another release candidate. The list
1753here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001754
Guido van Rossum5b08f132001-04-16 02:05:23 +00001755Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001756
Guido van Rossum5b08f132001-04-16 02:05:23 +00001757- Tim discovered a nasty bug in the dictionary code, caused by
1758 PyDict_Next() calling dict_resize(), and the GC code's use of
1759 PyDict_Next() violating an assumption in dict_items(). This was
1760 fixed with considerable amounts of band-aid, but the net effect is a
1761 saner and more robust implementation.
1762
1763- Made a bunch of symbols static that were accidentally global.
1764
1765Build and Ports
1766
1767- The setup.py script didn't check for a new enough version of zlib
1768 (1.1.3 is needed). Now it does.
1769
1770- Changed "make clean" target to also remove shared libraries.
1771
1772- Added a more general warning about the SGI Irix optimizer to README.
1773
1774Library
1775
1776- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1777 omitted the slash between host and file.html.
1778
1779- The mailbox module's _Mailbox class contained a completely broken
1780 and undocumented seek() method. Ripped it out.
1781
1782- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1783 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1784
1785- Fixed a few last-minute bugs in unittest.
1786
1787Extensions
1788
1789- Reverted the patch to the OpenSSL code in socketmodule.c to support
1790 RAND_status() and the EGD, and the subsequent patch that tried to
1791 fix it for pre-0.9.5 versions; the problem with the patch is that on
1792 some systems it issues a warning whenever socket is imported, and
1793 that's unacceptable.
1794
1795Tests
1796
1797- Fixed the pickle tests to work with "import test.test_pickle".
1798
1799- Tweaked test_locale.py to actually run the test Windows.
1800
1801- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1802 not "wb" (which is not a valid mode at all).
1803
1804- Fix pstats browser crashes. Import readline if it exists to make
1805 the user interface nicer.
1806
1807- Add "import thread" to the top of test modules that import the
1808 threading module (test_asynchat and test_threadedtempfile). This
1809 prevents test failures caused by a broken threading module resulting
1810 from a previously caught failed import.
1811
1812- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1813 needed on some platforms (e.g. Solaris 8) when the tests are run
1814 twice in succession.
1815
1816- Skip rather than fail test_sunaudiodev if no audio device is found.
1817
1818
1819What's New in Python 2.1c1?
1820===========================
1821
1822This list was significantly updated when 2.1c2 was released; the 2.1c1
1823release didn't mention most changes that were actually part of 2.1c1:
1824
1825Legal
1826
1827- Copyright was assigned to the Python Software Foundation (PSF) and a
1828 PSF license (very similar to the CNRI license) was added.
1829
1830- The CNRI copyright notice was updated to include 2001.
1831
1832Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001833
Guido van Rossumc9932722001-04-12 02:31:27 +00001834- After a public outcry, assignment to __debug__ is no longer illegal;
1835 instead, a warning is issued. It will become illegal in 2.2.
1836
Guido van Rossum5b08f132001-04-16 02:05:23 +00001837- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1838 "%#x" now always prepends "0x", even if the value is zero.
1839
1840- Fixed some nits in the bytecode compiler.
1841
1842- Fixed core dumps when calling certain kinds of non-functions.
1843
1844- Fixed various core dumps caused by reference count bugs.
1845
1846Build and Ports
1847
1848- Use INSTALL_SCRIPT to install script files.
1849
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001850- New port: SCO Unixware 7, by Billy G. Allie.
1851
Guido van Rossum5b08f132001-04-16 02:05:23 +00001852- Updated RISCOS port.
1853
1854- Updated BeOS port and notes.
1855
1856- Various other porting problems resolved.
1857
1858Library
1859
1860- The TERMIOS and SOCKET modules are now truly obsolete and
1861 unnecessary. Their symbols are incorporated in the termios and
1862 socket modules.
1863
1864- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1865 better tests for pickling.
1866
1867- threading: make Condition.wait() robust against KeyboardInterrupt.
1868
1869- zipfile: add support to zipfile to support opening an archive
1870 represented by an open file rather than a file name. Fix bug where
1871 the archive was not properly closed. Fixed a bug in this bugfix
1872 where flush() was called for a read-only file.
1873
1874- imputil: added an uninstall() method to the ImportManager.
1875
1876- Canvas: fixed bugs in lower() and tkraise() methods.
1877
1878- SocketServer: API change (added overridable close_request() method)
1879 so that the TCP server can explicitly close the request.
1880
1881- pstats: Eric Raymond added a simple interactive statistics browser,
1882 invoked when the module is run as a script.
1883
1884- locale: fixed a problem in format().
1885
1886- webbrowser: made it work when the BROWSER environment variable has a
1887 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1888 KDE 2. Fixed some other nits.
1889
1890- unittest: changes to allow using a different exception than
1891 AssertionError, and added a few more function aliases. Some other
1892 small changes.
1893
1894- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1895
1896- asynchat: fixed a critical bug in asynchat that slipped through the
1897 2.1b2 release. Fixed another rare bug.
1898
1899- Fix some unqualified except: clauses (always a bad code example).
1900
1901XML
1902
1903- pyexpat: new API get_version_string().
1904
1905- Fixed some minidom bugs.
1906
1907Extensions
1908
1909- Fixed a core dump in _weakref. Removed the weakref.mapping()
1910 function (it adds nothing to the API).
1911
1912- Rationalized the use of header files in the readline module, to make
1913 it compile (albeit with some warnings) with the very recent readline
1914 4.2, without breaking for earlier versions.
1915
1916- Hopefully fixed a buffering problem in linuxaudiodev.
1917
1918- Attempted a fix to make the OpenSSL support in the socket module
1919 work again with pre-0.9.5 versions of OpenSSL.
1920
1921Tests
1922
1923- Added a test case for asynchat and asyncore.
1924
1925- Removed coupling between tests where one test failing could break
1926 another.
1927
1928Tools
1929
1930- Ping added an interactive help browser to pydoc, fixed some nits
1931 in the rest of the pydoc code, and added some features to his
1932 inspect module.
1933
1934- An updated python-mode.el version 4.1 which integrates Ken
1935 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1936 much nicer in XEmacs and Emacs. When stepping through your program
1937 with pdb, in either the shell window or the *Python* window, the
1938 source file and line will be tracked by an arrow. Very cool!
1939
1940- IDLE: syntax warnings in interactive mode are changed into errors.
1941
1942- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001943 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001944
1945- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001946
Barry Warsaw11e89c72001-04-11 20:37:57 +00001947
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001948What's New in Python 2.1 beta 2?
1949================================
1950
Guido van Rossum053ae352001-03-22 14:17:21 +00001951(Unlisted are many fixed bugs, more documentation, etc.)
1952
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001953Core language, builtins, and interpreter
1954
Guido van Rossum053ae352001-03-22 14:17:21 +00001955- The nested scopes work (enabled by "from __future__ import
1956 nested_scopes") is completed; in particular, the future now extends
1957 into code executed through exec, eval() and execfile(), and into the
1958 interactive interpreter.
1959
1960- When calling a base class method (e.g. BaseClass.__init__(self)),
1961 this is now allowed even if self is not strictly spoken a class
1962 instance (e.g. when using metaclasses or the Don Beaudry hook).
1963
1964- Slice objects are now comparable but not hashable; this prevents
1965 dict[:] from being accepted but meaningless.
1966
1967- Complex division is now calculated using less braindead algorithms.
1968 This doesn't change semantics except it's more likely to give useful
1969 results in extreme cases. Complex repr() now uses full precision
1970 like float repr().
1971
1972- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1973
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001974- It is illegal to assign to the name __debug__, which is set when the
1975 interpreter starts. It is effectively a compile-time constant.
1976
1977- A warning will be issued if a global statement for a variable
1978 follows a use or assignment of that variable.
1979
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001980Standard library
1981
Guido van Rossum053ae352001-03-22 14:17:21 +00001982- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1983 inspired by JUnit), is now part of the standard library. You now
1984 have a choice of two testing frameworks: unittest requires you to
1985 write testcases as separate code, doctest gathers them from
1986 docstrings. Both approaches have their advantages and
1987 disadvantages.
1988
1989- A new module Tix was added, which wraps the Tix extension library
1990 for Tk. With that module, it is not necessary to statically link
1991 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1992 require" command. See Demo/tix/.
1993
1994- tzparse.py is now obsolete.
1995
1996- In gzip.py, the seek() and tell() methods are removed -- they were
1997 non-functional anyway, and it's better if callers can test for their
1998 existence with hasattr().
1999
2000Python/C API
2001
2002- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
2003 that's already in the dictionary during a PyDict_Next() iteration.
2004 This used to fail occasionally when a dictionary resize operation
2005 could be triggered that would rehash all the keys. All other
2006 modifications to the dictionary are still off-limits during a
2007 PyDict_Next() iteration!
2008
2009- New extended APIs related to passing compiler variables around.
2010
2011- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
2012 implement isinstance() and issubclass().
2013
2014- Py_BuildValue() now has a "D" conversion to create a Python complex
2015 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00002016
Fred Drake4e262a92001-03-22 18:26:47 +00002017- Extensions types which support weak references must now set the
2018 field allocated for the weak reference machinery to NULL themselves;
2019 this is done to avoid the cost of checking each object for having a
2020 weakly referencable type in PyObject_INIT(), since most types are
2021 not weakly referencable.
2022
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002023- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
2024 free variables and cell variables to and from the frame's f_locals.
2025
2026- Variants of several functions defined in pythonrun.h have been added
2027 to support the nested_scopes future statement. The variants all end
2028 in Flags and take an extra argument, a PyCompilerFlags *; examples:
2029 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
2030 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00002031 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00002032
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002033Distutils
2034
2035- the sdist command now writes a PKG-INFO file, as described in PEP 241,
2036 into the release tree.
2037
Tim Peters0e57abf2001-05-02 07:39:38 +00002038- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002039 (an uninstaller, more customization of the installer's display)
2040
2041- from Jack Jansen: added Mac-specific code to generate a dialog for
2042 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00002043 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002044 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00002045
2046- added 'platforms' and 'keywords' to the set of metadata that can be
2047 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00002048
2049- applied patches from Jason Tishler to make the compiler class work with
2050 Cygwin.
2051
2052
Tim Peters2fe289a2001-03-01 22:19:38 +00002053What's New in Python 2.1 beta 1?
2054================================
Tim Petersd66595f2001-02-04 03:09:53 +00002055
2056Core language, builtins, and interpreter
2057
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00002058- Following an outcry from the community about the amount of code
2059 broken by the nested scopes feature introduced in 2.1a2, we decided
2060 to make this feature optional, and to wait until Python 2.2 (or at
2061 least 6 months) to make it standard. The option can be enabled on a
2062 per-module basis by adding "from __future__ import nested_scopes" at
2063 the beginning of a module (before any other statements, but after
2064 comments and an optional docstring). See PEP 236 (Back to the
2065 __future__) for a description of the __future__ statement. PEP 227
2066 (Statically Nested Scopes) has been updated to reflect this change,
2067 and to clarify the semantics in a number of endcases.
2068
2069- The nested scopes code, when enabled, has been hardened, and most
2070 bugs and memory leaks in it have been fixed.
2071
2072- Compile-time warnings are now generated for a number of conditions
2073 that will break or change in meaning when nested scopes are enabled:
2074
2075 - Using "from...import *" or "exec" without in-clause in a function
2076 scope that also defines a lambda or nested function with one or
2077 more free (non-local) variables. The presence of the import* or
2078 bare exec makes it impossible for the compiler to determine the
2079 exact set of local variables in the outer scope, which makes it
2080 impossible to determine the bindings for free variables in the
2081 inner scope. To avoid the warning about import *, change it into
2082 an import of explicitly name object, or move the import* statement
2083 to the global scope; to avoid the warning about bare exec, use
2084 exec...in... (a good idea anyway -- there's a possibility that
2085 bare exec will be deprecated in the future).
2086
2087 - Use of a global variable in a nested scope with the same name as a
2088 local variable in a surrounding scope. This will change in
2089 meaning with nested scopes: the name in the inner scope will
2090 reference the variable in the outer scope rather than the global
2091 of the same name. To avoid the warning, either rename the outer
2092 variable, or use a global statement in the inner function.
2093
Neil Schemenauera35c6882001-02-27 04:45:05 +00002094- An optional object allocator has been included. This allocator is
2095 optimized for Python objects and should be faster and use less memory
2096 than the standard system allocator. It is not enabled by default
2097 because of possible thread safety problems. The allocator is only
2098 protected by the Python interpreter lock and it is possible that some
2099 extension modules require a thread safe allocator. The object
2100 allocator can be enabled by providing the "--with-pymalloc" option to
2101 configure.
2102
Tim Petersd66595f2001-02-04 03:09:53 +00002103Standard library
2104
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002105- pyexpat now detects the expat version if expat.h defines it. A
2106 number of additional handlers are provided, which are only available
2107 since expat 1.95. In addition, the methods SetParamEntityParsing and
2108 GetInputContext of Parser objects are available with 1.95.x
2109 only. Parser objects now provide the ordered_attributes and
2110 specified_attributes attributes. A new module expat.model was added,
2111 which offers a number of additional constants if 1.95.x is used.
2112
2113- xml.dom offers the new functions registerDOMImplementation and
2114 getDOMImplementation.
2115
2116- xml.dom.minidom offers a toprettyxml method. A number of DOM
2117 conformance issues have been resolved. In particular, Element now
2118 has an hasAttributes method, and the handling of namespaces was
2119 improved.
2120
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002121- Ka-Ping Yee contributed two new modules: inspect.py, a module for
2122 getting information about live Python code, and pydoc.py, a module
2123 for interactively converting docstrings to HTML or text.
2124 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00002125 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00002126 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
2127 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00002128
Tim Peters1eff7962001-03-01 02:31:33 +00002129- New library module difflib.py, primarily packaging the SequenceMatcher
2130 class at the heart of the popular ndiff.py file-comparison tool.
2131
2132- doctest.py (a framework for verifying Python code examples in docstrings)
2133 is now part of the std library.
2134
Tim Petersd66595f2001-02-04 03:09:53 +00002135Windows changes
2136
Guido van Rossume3955a82001-03-02 14:05:59 +00002137- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
2138 small GUI that lets you browse the module docstrings using your
2139 default web browser.
2140
Tim Peters1eff7962001-03-01 02:31:33 +00002141- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
2142 Platforms) is implemented. See
2143
2144 http://python.sourceforge.net/peps/pep-0235.html
2145
2146 for full details, especially the "Current Lower-Left Semantics" section.
2147 The new Windows import rules are simpler than before:
2148
2149 A. If the PYTHONCASEOK environment variable exists, same as
2150 before: silently accept the first case-insensitive match of any
2151 kind; raise ImportError if none found.
2152
2153 B. Else search sys.path for the first case-sensitive match; raise
2154 ImportError if none found.
2155
2156 The same rules have been implented on other platforms with case-
2157 insensitive but case-preserving filesystems too (including Cygwin, and
2158 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00002159
Tim Peters25a9ce32001-02-19 07:06:36 +00002160- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2161 what it's supposed to do (and does do under NT and 2000) via direct
2162 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002163 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002164 all Win9x systems before.
2165
Tim Peters1eff7962001-03-01 02:31:33 +00002166- Build: Subproject _test (effectively) renamed to _testcapi.
2167
Tim Peters2fe289a2001-03-01 22:19:38 +00002168New platforms
2169
2170- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2171 Thanks to Steven Majewski!
2172
2173- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2174 Tishler!
2175
Guido van Rossum9089b272001-03-02 06:49:50 +00002176- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2177 Schwertberger! See RISCOS/README for more information -- it seems
2178 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002179 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002180
Tim Peters25a9ce32001-02-19 07:06:36 +00002181
Tim Petersd7b5e882001-01-25 03:36:26 +00002182What's New in Python 2.1 alpha 2?
2183=================================
Tim Peters40ead762001-01-27 05:35:26 +00002184
Tim Petersd7b5e882001-01-25 03:36:26 +00002185Core language, builtins, and interpreter
2186
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002187- Scopes nest. If a name is used in a function or class, but is not
2188 local, the definition in the nearest enclosing function scope will
2189 be used. One consequence of this change is that lambda statements
2190 could reference variables in the namespaces where the lambda is
2191 defined. In some unusual cases, this change will break code.
2192
2193 In all previous version of Python, names were resolved in exactly
2194 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002195 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002196 function A is defined within a function B, the names bound in B are
2197 not visible in A. The new rules make names bound in B visible in A,
2198 unless A contains a name binding that hides the binding in B.
2199
2200 Section 4.1 of the reference manual describes the new scoping rules
2201 in detail. The test script in Lib/test/test_scope.py demonstrates
2202 some of the effects of the change.
2203
2204 The new rules will cause existing code to break if it defines nested
2205 functions where an outer function has local variables with the same
2206 name as globals or builtins used by the inner function. Example:
2207
2208 def munge(str):
2209 def helper(x):
2210 return str(x)
2211 if type(str) != type(''):
2212 str = helper(str)
2213 return str.strip()
2214
2215 Under the old rules, the name str in helper() is bound to the
2216 builtin function str(). Under the new rules, it will be bound to
2217 the argument named str and an error will occur when helper() is
2218 called.
2219
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002220- The compiler will report a SyntaxError if "from ... import *" occurs
2221 in a function or class scope. The language reference has documented
2222 that this case is illegal, but the compiler never checked for it.
2223 The recent introduction of nested scope makes the meaning of this
2224 form of name binding ambiguous. In a future release, the compiler
2225 may allow this form when there is no possibility of ambiguity.
2226
Tim Peters40ead762001-01-27 05:35:26 +00002227- repr(string) is easier to read, now using hex escapes instead of octal,
2228 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2229
2230 >>> "\texample \r\n" + chr(0) + chr(255)
2231 '\texample \r\n\x00\xff' # in 2.1
2232 '\011example \015\012\000\377' # in 2.0
2233
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002234- Functions are now compared and hashed by identity, not by value, since
2235 the func_code attribute is writable.
2236
Fred Drakefb9d7122001-02-01 20:00:40 +00002237- Weak references (PEP 205) have been added. This involves a few
2238 changes in the core, an extension module (_weakref), and a Python
2239 module (weakref). The weakref module is the public interface. It
2240 includes support for "explicit" weak references, proxy objects, and
2241 mappings with weakly held values.
2242
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002243- A 'continue' statement can now appear in a try block within the body
2244 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002245 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002246
Tim Petersd7b5e882001-01-25 03:36:26 +00002247Standard library
2248
Barry Warsaw30dbd142001-01-31 22:14:01 +00002249- mailbox.py now has a new class, PortableUnixMailbox which is
2250 identical to UnixMailbox but uses a more portable scheme for
2251 determining From_ separators. Also, the constructors for all the
2252 classes in this module have a new optional `factory' argument, which
2253 is a callable used when new message classes must be instantiated by
2254 the next() method.
2255
Tim Petersd7b5e882001-01-25 03:36:26 +00002256- random.py is now self-contained, and offers all the functionality of
2257 the now-deprecated whrandom.py. See the docs for details. random.py
2258 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002259 and restoring the internal state of the generator; and jumpahead(n),
2260 for quickly forcing the internal state to be the same as if n calls to
2261 random() had been made. The latter is particularly useful for multi-
2262 threaded programs, creating one instance of the random.Random() class for
2263 each thread, then using .jumpahead() to force each instance to use a
2264 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002265
Tim Peters0de88fc2001-02-01 04:59:18 +00002266- random.py's seed() function is new. For bit-for-bit compatibility with
2267 prior releases, use the whseed function instead. The new seed function
2268 addresses two problems: (1) The old function couldn't produce more than
2269 about 2**24 distinct internal states; the new one about 2**45 (the best
2270 that can be done in the Wichmann-Hill generator). (2) The old function
2271 sometimes produced identical internal states when passed distinct
2272 integers, and there was no simple way to predict when that would happen;
2273 the new one guarantees to produce distinct internal states for all
2274 arguments in [0, 27814431486576L).
2275
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002276- The socket module now supports raw packets on Linux. The socket
2277 family is AF_PACKET.
2278
Tim Peters9ea17ac2001-02-02 05:57:15 +00002279- test_capi.py is a start at running tests of the Python C API. The tests
2280 are implemented by the new Modules/_testmodule.c.
2281
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002282- A new extension module, _symtable, provides provisional access to the
2283 internal symbol table used by the Python compiler. A higher-level
2284 interface will be added on top of _symtable in a future release.
2285
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002286- Removed the obsolete soundex module.
2287
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002288- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2289 the isSameNode method; NamedNodeMap the get method.
2290
2291- xml.sax.expatreader supports the lexical handler property; it
2292 generates comment, startCDATA, and endCDATA events.
2293
Tim Petersee826f82001-01-31 19:39:44 +00002294Windows changes
2295
2296- Build procedure: the zlib project is built in a different way that
2297 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002298 the zlib binary used. See PCbuild\readme.txt for details. Your old
2299 zlib-related directories can be deleted; you'll need to download fresh
2300 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002301
Tim Peters9ea17ac2001-02-02 05:57:15 +00002302- Build: New subproject _test for the benefit of test_capi.py (see above).
2303
Tim Petersb16c56f2001-02-02 21:24:51 +00002304- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2305 interface to some Python compiler internals).
2306
2307- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002308 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002309
Tim Petersa3a3a032000-11-30 05:22:44 +00002310What's New in Python 2.1 alpha 1?
2311=================================
2312
2313Core language, builtins, and interpreter
2314
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002315- There is a new Unicode companion to the PyObject_Str() API
2316 called PyObject_Unicode(). It behaves in the same way as the
2317 former, but assures that the returned value is an Unicode object
2318 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002319
Guido van Rossumf98eda02001-01-17 15:54:45 +00002320- The comparison operators support "rich comparison overloading" (PEP
2321 207). C extension types can provide a rich comparison function in
2322 the new tp_richcompare slot in the type object. The cmp() function
2323 and the C function PyObject_Compare() first try the new rich
2324 comparison operators before trying the old 3-way comparison. There
2325 is also a new C API PyObject_RichCompare() (which also falls back on
2326 the old 3-way comparison, but does not constrain the outcome of the
2327 rich comparison to a Boolean result).
2328
2329 The rich comparison function takes two objects (at least one of
2330 which is guaranteed to have the type that provided the function) and
2331 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2332 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2333 object, which may be NotImplemented (in which case the tp_compare
2334 slot function is used as a fallback, if defined).
2335
2336 Classes can overload individual comparison operators by defining one
2337 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002338 __ge__. There are no explicit "reflected argument" versions of
2339 these; instead, __lt__ and __gt__ are each other's reflection,
2340 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2341 reflection (similar at the C level). No other implications are
2342 made; in particular, Python does not assume that == is the Boolean
2343 inverse of !=, or that < is the Boolean inverse of >=. This makes
2344 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002345
2346 Classes or types that want to implement (in)equality tests but not
2347 the ordering operators (i.e. unordered types) should implement ==
2348 and !=, and raise an error for the ordering operators.
2349
Guido van Rossuma88479f2001-01-18 14:28:08 +00002350 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002351 Boolean; e.g. a matrix type might want to return a matrix of bits
2352 for A < B, giving elementwise comparisons. Such types should ensure
2353 that any interpretation of their value in a Boolean context raises
2354 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2355 at the C level) to always raise an exception.
2356
Guido van Rossuma88479f2001-01-18 14:28:08 +00002357- Complex numbers use rich comparisons to define == and != but raise
2358 an exception for <, <=, > and >=. Unfortunately, this also means
2359 that cmp() of two complex numbers raises an exception when the two
2360 numbers differ. Since it is not mathematically meaningful to compare
2361 complex numbers except for equality, I hope that this doesn't break
2362 too much code.
2363
Tim Peters3389f192001-02-18 08:48:49 +00002364- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002365 not defined by the language, other than that it's arbitrary but
2366 consistent (see the Reference Manual). An implementation detail changed
2367 in 2.1a1 such that None now compares less than any other object. Code
2368 relying on this new behavior (like code that relied on the previous
2369 behavior) does so at its own risk.
2370
Barry Warsaw573b5412001-01-15 20:43:18 +00002371- Functions and methods now support getting and setting arbitrarily
2372 named attributes (PEP 232). Functions have a new __dict__
2373 (a.k.a. func_dict) which hold the function attributes. Methods get
2374 and set attributes on their underlying im_func. It is a TypeError
2375 to set an attribute on a bound method.
2376
Guido van Rossum051e3352001-01-15 19:11:10 +00002377- The xrange() object implementation has been improved so that
2378 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2379 limitation that in this case len(xrange(sys.maxint)) can't be
2380 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2381 work fine as long as the index i doesn't actually reach 2**31.
2382 (Python uses regular ints for sequence and string indices; fixing
2383 that is much more work.)
2384
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002385- Two changes to from...import:
2386
Guido van Rossumba381232001-02-03 15:06:40 +00002387 1) "from M import X" now works even if (after loading module M)
2388 sys.modules['M'] is not a real module; it's basically a getattr()
2389 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002390
2391 2) "from M import *" now looks for M.__all__ to decide which names to
2392 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2393 filters out names starting with '_' as before. Whether or not
2394 __all__ exists, there's no restriction on the type of M.
2395
Guido van Rossumf61f1662001-01-10 20:13:55 +00002396- File objects have a new method, xreadlines(). This is the fastest
2397 way to iterate over all lines in a file:
2398
2399 for line in file.xreadlines():
2400 ...do something to line...
2401
2402 See the xreadlines module (mentioned below) for how to do this for
2403 other file-like objects.
2404
2405- Even if you don't use file.xreadlines(), you may expect a speedup on
2406 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002407 quite a bit in platform-specific ways: on systems (like Linux) that
2408 support flockfile(), getc_unlocked(), and funlockfile(), those are
2409 used by default. On systems (like Windows) without getc_unlocked(),
2410 a complicated (but still thread-safe) method using fgets() is used by
2411 default.
2412
Tim Petersd52269b2001-01-25 06:23:18 +00002413 You can force use of the fgets() method by #define'ing
2414 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002415 getc_unlocked()).
2416
Tim Petersd52269b2001-01-25 06:23:18 +00002417 You can force fgets() not to be used by #define'ing
2418 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002419 test_bufio.py fails -- and let us know if it does!).
2420
2421- In addition, the fileinput module, while still slower than the other
2422 methods on most platforms, has been sped up too, by using
2423 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002424
2425- Support for run-time warnings has been added, including a new
2426 command line option (-W) to specify the disposition of warnings.
2427 See the description of the warnings module below.
2428
2429- Extensive changes have been made to the coercion code. This mostly
2430 affects extension modules (which can now implement mixed-type
2431 numerical operators without having to use coercion), but
2432 occasionally, in boundary cases the coercion semantics have changed
2433 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002434 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002435 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002436 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002437
Guido van Rossumf98eda02001-01-17 15:54:45 +00002438- In connection with the coercion changes, a new built-in singleton
2439 object, NotImplemented is defined. This can be returned for
2440 operations that wish to indicate they are not implemented for a
2441 particular combination of arguments. From C, this is
2442 Py_NotImplemented.
2443
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002444- The interpreter accepts now bytecode files on the command line even
2445 if they do not have a .pyc or .pyo extension. On Linux, after executing
2446
Martin v. Löwise214baa2001-02-04 22:37:56 +00002447import imp,sys,string
2448magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2449reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2450open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002451
2452 any byte code file can be used as an executable (i.e. as an argument
2453 to execve(2)).
2454
Tim Peters9940b802000-12-01 07:59:35 +00002455- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002456 character. In 1.6 and earlier, they never produced a sign,
2457 and raised an error if the value of the long was too large
2458 to fit in a Python int. In 2.0, they produced a sign if and
2459 only if too large to fit in an int. This was inconsistent
2460 across platforms (because the size of an int varies across
2461 platforms), and inconsistent with hex() and oct(). Example:
2462
2463 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002464 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002465 'ffffffbe' # in 2.0 and before, on 32-bit machines
2466 >>> hex(-0x42L)
2467 '-0x42L' # in all versions of Python
2468
Tim Peters9940b802000-12-01 07:59:35 +00002469 The behavior of %d formats for negative Python longs remains
2470 the same as in 2.0 (although in 1.6 and before, they raised
2471 an error if the long didn't fit in a Python int).
2472
2473 %u formats don't make sense for Python longs, but are allowed
2474 and treated the same as %d in 2.1. In 2.0, a negative long
2475 formatted via %u produced a sign if and only if too large to
2476 fit in an int. In 1.6 and earlier, a negative long formatted
2477 via %u raised an error if it was too big to fit in an int.
2478
Guido van Rossum3661d392000-12-12 22:10:31 +00002479- Dictionary objects have an odd new method, popitem(). This removes
2480 an arbitrary item from the dictionary and returns it (in the form of
2481 a (key, value) pair). This can be useful for algorithms that use a
2482 dictionary as a bag of "to do" items and repeatedly need to pick one
2483 item. Such algorithms normally end up running in quadratic time;
2484 using popitem() they can usually be made to run in linear time.
2485
Tim Peters36cdad12000-12-29 02:06:45 +00002486Standard library
2487
Thomas Woutersfe385252001-01-19 23:16:56 +00002488- In the time module, the time argument to the functions strftime,
2489 localtime, gmtime, asctime and ctime is now optional, defaulting to
2490 the current time (in the local timezone).
2491
Guido van Rossumda91f222001-01-15 16:36:08 +00002492- The ftplib module now defaults to passive mode, which is deemed a
2493 more useful default given that clients are often inside firewalls
2494 these days. Note that this could break if ftplib is used to connect
2495 to a *server* that is inside a firewall, from outside; this is
2496 expected to be a very rare situation. To fix that, you can call
2497 ftp.set_pasv(0).
2498
Martin v. Löwis10a27872001-01-13 09:54:41 +00002499- The module site now treats .pth files not only for path configuration,
2500 but also supports extensions to the initialization code: Lines starting
2501 with import are executed.
2502
Guido van Rossumf61f1662001-01-10 20:13:55 +00002503- There's a new module, warnings, which implements a mechanism for
2504 issuing and filtering warnings. There are some new built-in
2505 exceptions that serve as warning categories, and a new command line
2506 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2507 turns warnings into errors). warnings.warn(message[, category])
2508 issues a warning message; this can also be called from C as
2509 PyErr_Warn(category, message).
2510
2511- A new module xreadlines was added. This exports a single factory
2512 function, xreadlines(). The intention is that this code is the
2513 absolutely fastest way to iterate over all lines in an open
2514 file(-like) object:
2515
2516 import xreadlines
2517 for line in xreadlines.xreadlines(file):
2518 ...do something to line...
2519
2520 This is equivalent to the previous the speed record holder using
2521 file.readlines(sizehint). Note that if file is a real file object
2522 (as opposed to a file-like object), this is equivalent:
2523
2524 for line in file.xreadlines():
2525 ...do something to line...
2526
Tim Peters36cdad12000-12-29 02:06:45 +00002527- The bisect module has new functions bisect_left, insort_left,
2528 bisect_right and insort_right. The old names bisect and insort
2529 are now aliases for bisect_right and insort_right. XXX_right
2530 and XXX_left methods differ in what happens when the new element
2531 compares equal to one or more elements already in the list: the
2532 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002533 right. Code that doesn't care where equal elements end up should
2534 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002535
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002536- The new curses.panel module wraps the panel library that forms part
2537 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2538
Guido van Rossumf61f1662001-01-10 20:13:55 +00002539- The SocketServer module now sets the allow_reuse_address flag by
2540 default in the TCPServer class.
2541
2542- A new function, sys._getframe(), returns the stack frame pointer of
2543 the caller. This is intended only as a building block for
2544 higher-level mechanisms such as string interpolation.
2545
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002546- The pyexpat module supports a number of new handlers, which are
2547 available only in expat 1.2. If invocation of a callback fails, it
2548 will report an additional frame in the traceback. Parser objects
2549 participate now in garbage collection. If expat reports an unknown
2550 encoding, pyexpat will try to use a Python codec; that works only
2551 for single-byte charsets. The parser type objects is exposed as
2552 XMLParserObject.
2553
2554- xml.dom now offers standard definitions for symbolic node type and
2555 exception code constants, and a hierarchy of DOM exceptions. minidom
2556 was adjusted to use them.
2557
2558- The conformance of xml.dom.minidom to the DOM specification was
2559 improved. It detects a number of additional error cases; the
2560 previous/next relationship works even when the tree is modified;
2561 Node supports the normalize() method; NamedNodeMap, DocumentType and
2562 DOMImplementation classes were added; Element supports the
2563 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2564 method.
2565
Guido van Rossumf61f1662001-01-10 20:13:55 +00002566Build issues
2567
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002568- For Unix (and Unix-compatible) builds, configuration and building of
2569 extension modules is now greatly automated. Rather than having to
2570 edit the Modules/Setup file to indicate which modules should be
2571 built and where their include files and libraries are, a
2572 distutils-based setup.py script now takes care of building most
2573 extension modules. All extension modules built this way are built
2574 as shared libraries. Only a few modules that must be linked
2575 statically are still listed in the Setup file; you won't need to
2576 edit their configuration.
2577
2578- Python should now build out of the box on Cygwin. If it doesn't,
2579 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002580
2581- Python now always uses its own (renamed) implementation of getopt()
2582 -- there's too much variation among C library getopt()
2583 implementations.
2584
2585- C++ compilers are better supported; the CXX macro is always set to a
2586 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002587
Tim Petersd92dfe02000-12-12 01:18:41 +00002588Windows changes
2589
2590- select module: By default under Windows, a select() call
2591 can specify no more than 64 sockets. Python now boosts
2592 this Microsoft default to 512. If you need even more than
2593 that, see the MS docs (you'll need to #define FD_SETSIZE
2594 and recompile Python from source).
2595
Guido van Rossumf61f1662001-01-10 20:13:55 +00002596- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2597 subdirectory is no more!
2598
Tim Petersa3a3a032000-11-30 05:22:44 +00002599
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002600What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002601=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002602
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002603Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002604changes are in the file HISTORY. If you are making the jump directly
2605from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2606HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002607
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002608Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2609the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2610http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002611
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002612--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002613
2614======================================================================
2615
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002616What's new in 2.0 (since release candidate 1)?
2617==============================================
2618
2619Standard library
2620
2621- The copy_reg module was modified to clarify its intended use: to
2622 register pickle support for extension types, not for classes.
2623 pickle() will raise a TypeError if it is passed a class.
2624
2625- Fixed a bug in gettext's "normalize and expand" code that prevented
2626 it from finding an existing .mo file.
2627
2628- Restored support for HTTP/0.9 servers in httplib.
2629
Tim Peters989b7b92000-10-16 20:24:53 +00002630- The math module was changed to stop raising OverflowError in case of
2631 underflow, and return 0 instead in underflow cases. Whether Python
2632 used to raise OverflowError in case of underflow was platform-
2633 dependent (it did when the platform math library set errno to ERANGE
2634 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002635
2636- Fixed a bug in StringIO that occurred when the file position was not
2637 at the end of the file and write() was called with enough data to
2638 extend past the end of the file.
2639
2640- Fixed a bug that caused Tkinter error messages to get lost on
2641 Windows. The bug was fixed by replacing direct use of
2642 interp->result with Tcl_GetStringResult(interp).
2643
2644- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2645 redirect response.
2646
2647- Several changes were made to distutils: Some debugging code was
2648 removed from util. Fixed the installer used when an external zip
2649 program (like WinZip) is not found; the source code for this
2650 installer is in Misc/distutils. check_lib() was modified to behave
2651 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2652 test for whether installed modules are on sys.path was changed to
2653 use both normcase() and normpath().
2654
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002655- Several minor bugs were fixed in the xml package (the minidom,
2656 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002657
2658- The regression test driver (regrtest.py) behavior when invoked with
2659 -l changed: It now reports a count of objects that are recognized as
2660 garbage but not freed by the garbage collector.
2661
Tim Peters989b7b92000-10-16 20:24:53 +00002662- The regression test for the math module was changed to test
2663 exceptional behavior when the test is run in verbose mode. Python
2664 cannot yet guarantee consistent exception behavior across platforms,
2665 so the exception part of test_math is run only in verbose mode, and
2666 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002667
2668Internals
2669
2670- PyOS_CheckStack() has been disabled on Win64, where it caused
2671 test_sre to fail.
2672
2673Build issues
2674
2675- Changed compiler flags, so that gcc is always invoked with -Wall and
2676 -Wstrict-prototypes. Users compiling Python with GCC should see
2677 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002678 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002679 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002680
Tim Petersa3a3a032000-11-30 05:22:44 +00002681- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002682
2683Tools and other miscellany
2684
2685- The compiler in Tools/compiler was updated to support the new
2686 language features introduced in 2.0: extended print statement, list
2687 comprehensions, and augmented assignments. The new compiler should
2688 also be backwards compatible with Python 1.5.2; the compiler will
2689 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002690 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002691
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002692What's new in 2.0 release candidate 1 (since beta 2)?
2693=====================================================
2694
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002695What is release candidate 1?
2696
2697We believe that release candidate 1 will fix all known bugs that we
2698intend to fix for the 2.0 final release. This release should be a bit
2699more stable than the previous betas. We would like to see even more
2700widespread testing before the final release, so we are producing this
2701release candidate. The final release will be exactly the same unless
2702any show-stopping (or brown bag) bugs are found by testers of the
2703release candidate.
2704
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002705All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002706to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002707
2708Core language, builtins, and interpreter
2709
2710- A bug that caused crashes when __coerce__ was used with augmented
2711 assignment, e.g. +=, was fixed.
2712
2713- Raise ZeroDivisionError when raising zero to a negative number,
2714 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2715 power operator and the result of math.pow(0.0, -2.0) will vary by
2716 platform. On Linux, it raises a ValueError.
2717
2718- A bug in Unicode string interpolation was fixed that occasionally
2719 caused errors with formats including "%%". For example, the
2720 following expression "%% %s" % u"abc" no longer raises a TypeError.
2721
2722- Compilation of deeply nested expressions raises MemoryError instead
2723 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2724
2725- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2726 rendering them useless. They are now written in binary mode again.
2727
2728Standard library
2729
2730- Keyword arguments are now accepted for most pattern and match object
2731 methods in SRE, the standard regular expression engine.
2732
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002733- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002734 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002735
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002736- Several bugs in the Unicode handling and error handling in _tkinter
2737 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002738
2739- Fix memory management errors in Merge() and Tkapp_Call() routines.
2740
2741- Several changes were made to cStringIO to make it compatible with
2742 the file-like object interface and with StringIO. If operations are
2743 performed on a closed object, an exception is raised. The truncate
2744 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002745 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002746
2747- There were many changes made to the linuxaudiodev module and its
2748 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002749 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002750
2751 Note that this module is named poorly, because it should work
2752 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002753 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002754
2755 The module now raises exceptions when errors occur instead of
2756 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2757 audio) and defines a getptr() method that calls the
2758 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2759
2760- The library_version attribute, introduced in an earlier beta, was
2761 removed because it can not be supported with early versions of the C
2762 readline library, which provides no way to determine the version at
2763 compile-time.
2764
2765- The binascii module is now enabled on Win64.
2766
Tim Peters46446d62000-10-09 21:19:31 +00002767- tokenize.py no longer suffers "recursion depth" errors when parsing
2768 programs with very long string literals.
2769
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002770Internals
2771
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002772- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002773 which is called when the interpreter starts up to determine where
2774 the standard library is installed. These vulnerabilities affect all
2775 previous versions of Python and can be exploited by setting very
2776 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2777 setuid Python script, although use of the wrapper in
2778 Misc/setuid-prog.c will eliminate the vulnerability.
2779
2780- Fixed garbage collection bugs in instance creation that were
2781 triggered when errors occurred during initialization. The solution,
2782 applied in cPickle and in PyInstance_New(), is to call
2783 PyObject_GC_Init() after the initialization of the object's
2784 container attributes is complete.
2785
2786- pyexpat adds definitions of PyModule_AddStringConstant and
2787 PyModule_AddObject if the Python version is less than 2.0, which
2788 provides compatibility with PyXML on Python 1.5.2.
2789
2790- If the platform has a bogus definition for LONG_BIT (the number of
2791 bits in a long), an error will be reported at compile time.
2792
2793- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2794 collection crashes and possibly other, unreported crashes.
2795
2796- Fixed a memory leak in _PyUnicode_Fini().
2797
2798Build issues
2799
2800- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002801 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002802 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002803
2804- The mmap.PAGESIZE constant is now initialized using sysconf when
2805 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2806
2807- The md5 file should now compile on all platforms.
2808
2809- The select module now compiles on platforms that do not define
2810 POLLRDNORM and related constants.
2811
2812- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002813 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002814
Jeremy Hylton10921202000-10-09 18:34:12 +00002815- BeOS: A number of changes were made to the build and installation
2816 process. ar-fake now operates on a directory of object files.
2817 dl_export.h is gone, and its macros now appear on the mwcc command
2818 line during build on PPC BeOS.
2819
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002820- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002821 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002822
2823- Cygwin: Support for shared libraries, Tkinter, and sockets.
2824
2825- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2826
2827Tools and other miscellany
2828
2829- Removed debugging prints from main used with freeze.
2830
Tim Peters46446d62000-10-09 21:19:31 +00002831- IDLE auto-indent no longer crashes when it encounters Unicode
2832 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002833
2834What's new in 2.0 beta 2 (since beta 1)?
2835========================================
2836
2837Core language, builtins, and interpreter
2838
Tim Peters482c0212000-09-26 06:33:09 +00002839- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002840 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002841
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002842- Add -h and -V command line options to print the usage message and
2843 Python version number and exit immediately.
2844
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002845- eval() and exec accept Unicode objects as code parameters.
2846
2847- getattr() and setattr() now also accept Unicode objects for the
2848 attribute name, which are converted to strings using the default
2849 encoding before lookup.
2850
2851- Multiplication on string and Unicode now does proper bounds
2852 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2853 string is too long."
2854
2855- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002856 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002857
Jeremy Hylton1b618592000-09-26 05:32:36 +00002858
2859Standard library and extensions
2860
Guido van Rossum5b08f132001-04-16 02:05:23 +00002861- socket module: the OpenSSL code now adds support for RAND_status()
2862 and EGD (Entropy Gathering Device).
2863
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002864- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002865 argument checking; it still takes no arguments.
2866
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002867- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002868
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002869- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002870
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002871- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002872
2873- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002874 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002875
2876- copy: Copy Unicode objects atomically.
2877
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002878- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002879
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002880- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002881
Fred Drake67233bc2000-09-26 16:40:27 +00002882- dbm: Add get() and setdefault() methods to dbm object. Add constant
2883 `library' to module that names the library used. Added doc strings
2884 and method names to error messages. Uses configure to determine
2885 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2886 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002887
2888- distutils: Update to version 0.9.3.
2889
2890- dl: Add several dl.RTLD_ constants.
2891
2892- fpectl: Now supported on FreeBSD.
2893
2894- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2895 found by the collector will be saved in gc.garbage. This is useful
2896 for debugging a program that creates reference cycles.
2897
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002898- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899 of HTTP class. Do not close socket on zero-length response. Do not
2900 crash when server sends invalid content-length header.
2901
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002902- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002903
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002904- marshal: When reading a short, sign-extend on platforms where shorts
2905 are bigger than 16 bits. When reading a long, repair the unportable
2906 sign extension that was being done for 64-bit machines. (It assumed
2907 that signed right shift sign-extends.)
2908
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002909- operator: Add contains(), invert(), __invert__() as aliases for
2910 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002911
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002912- os: Add support for popen2() and popen3() on all platforms where
2913 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002914
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002915- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002916 clicking on a file in Explorer (or passing the file name to the
2917 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002918
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002919- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002920 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002921
2922- pickle: Now raises ValueError when an invalid pickle that contains
2923 a non-string repr where a string repr was expected. This behavior
2924 matches cPickle.
2925
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002926- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002927
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002928- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002929
2930- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002931 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002932 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002933
2934- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002935 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002936
2937- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002938 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002939 few cycles during startup since the first call to
2940 setdefaultencoding() will initialize the codec registry and the
2941 encodings package.
2942
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002943- socket: Support for size hint in readlines() method of object returned
2944 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002945
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002946- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002947 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002948 is followed by whitespace.
2949
Tim Petersa3a3a032000-11-30 05:22:44 +00002950- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002951
2952- struct: Check ranges for bytes and shorts.
2953
2954- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002955 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002956
2957- Tkinter: Image objects are now guaranteed to have unique ids. Set
2958 event.delta to zero if Tk version doesn't support mousewheel.
2959 Removed some debugging prints.
2960
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002961- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002962
Fred Drake67233bc2000-09-26 16:40:27 +00002963- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002964 which works around a bug in Norton AntiVirus 2000 that leads directly
2965 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002966
2967- xml: New version detection code allows PyXML to override standard
2968 XML package if PyXML version is greater than 0.6.1.
2969
Fred Drake64bb3802000-09-26 16:21:35 +00002970- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2971 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2972 tree only for nodes which are sufficiently interesting to a specific
2973 application. Does not provide the HTML-specific extensions. Still
2974 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002975
Fred Drake64bb3802000-09-26 16:21:35 +00002976- xml.sax: SAX 2 support for Python, including all the handler
2977 interfaces needed to process XML 1.0 compliant XML. Some
2978 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002979
Fred Drake64bb3802000-09-26 16:21:35 +00002980- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2981 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002982
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002983
Jeremy Hylton1b618592000-09-26 05:32:36 +00002984C API
2985
2986- Add three new convenience functions for module initialization --
2987 PyModule_AddObject(), PyModule_AddIntConstant(), and
2988 PyModule_AddStringConstant().
2989
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002990- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002991 removed and add #error to Python.h if NULL isn't defined after
2992 #include of stdio.h.
2993
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002994- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002995 backwards compatibility (at the source level) with old extensions.
2996
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002997- A wrapper API was added for signal() and sigaction(). Instead of
2998 either function, always use PyOS_getsig() to get a signal handler
2999 and PyOS_setsig() to set one. A new convenience typedef
3000 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003001
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003002- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00003003 internal data buffer and size of a string object -- or the default
3004 encoded version of a Unicode object.
3005
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003006- PyString_Size() and PyString_AsString() accept Unicode objects.
3007
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003008- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00003009 exists). INT_MAX and LONG_MAX will always be defined, even if
3010 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003011
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003012- PyFloat_FromString takes a second argument, pend, that was
3013 effectively useless. It is now officially useless but preserved for
3014 backwards compatibility. If the pend argument is not NULL, *pend is
3015 set to NULL.
3016
3017- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
3018 for the attribute name. See note on getattr() above.
3019
3020- A few bug fixes to argument processing for Unicode.
3021 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
3022 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
3023 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00003024 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003025
3026- Py_BuildValue accepts B format (for bgen-generated code).
3027
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003028
Jeremy Hylton1b618592000-09-26 05:32:36 +00003029Internals
3030
3031- On Unix, fix code for finding Python installation directory so that
3032 it works when argv[0] is a relative path.
3033
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00003034- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003035 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00003036 rather than by generating a copy of the object.
3037
Tim Peters482c0212000-09-26 06:33:09 +00003038- Several of the internal Unicode tables are much smaller now, and
3039 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003040
Jeremy Hylton97693b02000-09-26 17:42:51 +00003041- In the garbage collector: Fixed bug in collection of tuples. Fixed
3042 bug that caused some instances to be removed from the container set
3043 while they were still live. Fixed parsing in gc.set_debug() for
3044 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003045
3046- Fixed refcount problem in instance deallocation that only occurred
3047 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
3048
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003049- On Windows, getpythonregpath is now protected against null data in
3050 registry key.
3051
3052- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00003053 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003054
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003055
Jeremy Hylton1b618592000-09-26 05:32:36 +00003056Build and platform-specific issues
3057
3058- Better support of GNU Pth via --with-pth configure option.
3059
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003060- Python/C API now properly exposed to dynamically-loaded extension
3061 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00003062
3063- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
3064 Don't define MS_SYNC to be zero when it is undefined. Added missing
3065 prototypes in posixmodule.c.
3066
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003067- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003068 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00003069
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003070- Fix largefile support on older NetBSD systems and OpenBSD by adding
3071 define for TELL64.
3072
3073
3074Tools and other miscellany
3075
3076- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
3077
3078- freeze: The modulefinder now works with 2.0 opcodes.
3079
Tim Petersa3a3a032000-11-30 05:22:44 +00003080- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00003081 Move hackery of sys.argv until after the Tk instance has been
3082 created, which allows the application-specific Tkinter
3083 initialization to be executed if present; also pass an explicit
3084 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00003085
Jeremy Hylton1b618592000-09-26 05:32:36 +00003086
3087What's new in 2.0 beta 1?
3088=========================
3089
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003090Source Incompatibilities
3091------------------------
3092
3093None. Note that 1.6 introduced several incompatibilities with 1.5.2,
3094such as single-argument append(), connect() and bind(), and changes to
3095str(long) and repr(float).
3096
3097
3098Binary Incompatibilities
3099------------------------
3100
3101- Third party extensions built for Python 1.5.x or 1.6 cannot be used
3102with Python 2.0; these extensions will have to be rebuilt for Python
31032.0.
3104
3105- On Windows, attempting to import a third party extension built for
3106Python 1.5.x or 1.6 results in an immediate crash; there's not much we
3107can do about this. Check your PYTHONPATH environment variable!
3108
3109- Python bytecode files (*.pyc and *.pyo) are not compatible between
3110releases.
3111
3112
3113Overview of Changes Since 1.6
3114-----------------------------
3115
3116There are many new modules (including brand new XML support through
3117the xml package, and i18n support through the gettext module); a list
3118of all new modules is included below. Lots of bugs have been fixed.
3119
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003120The process for making major new changes to the language has changed
3121since Python 1.6. Enhancements must now be documented by a Python
3122Enhancement Proposal (PEP) before they can be accepted.
3123
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003124There are several important syntax enhancements, described in more
3125detail below:
3126
3127 - Augmented assignment, e.g. x += 1
3128
3129 - List comprehensions, e.g. [x**2 for x in range(10)]
3130
3131 - Extended import statement, e.g. import Module as Name
3132
3133 - Extended print statement, e.g. print >> file, "Hello"
3134
3135Other important changes:
3136
3137 - Optional collection of cyclical garbage
3138
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003139Python Enhancement Proposal (PEP)
3140---------------------------------
3141
3142PEP stands for Python Enhancement Proposal. A PEP is a design
3143document providing information to the Python community, or describing
3144a new feature for Python. The PEP should provide a concise technical
3145specification of the feature and a rationale for the feature.
3146
3147We intend PEPs to be the primary mechanisms for proposing new
3148features, for collecting community input on an issue, and for
3149documenting the design decisions that have gone into Python. The PEP
3150author is responsible for building consensus within the community and
3151documenting dissenting opinions.
3152
3153The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003154
3155Augmented Assignment
3156--------------------
3157
3158This must have been the most-requested feature of the past years!
3159Eleven new assignment operators were added:
3160
Guido van Rossume905e952000-09-05 12:42:46 +00003161 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003162
3163For example,
3164
3165 A += B
3166
3167is similar to
3168
3169 A = A + B
3170
3171except that A is evaluated only once (relevant when A is something
3172like dict[index].attr).
3173
3174However, if A is a mutable object, A may be modified in place. Thus,
3175if A is a number or a string, A += B has the same effect as A = A+B
3176(except A is only evaluated once); but if a is a list, A += B has the
3177same effect as A.extend(B)!
3178
3179Classes and built-in object types can override the new operators in
3180order to implement the in-place behavior; the not-in-place behavior is
3181used automatically as a fallback when an object doesn't implement the
3182in-place behavior. For classes, the method name is derived from the
3183method name for the corresponding not-in-place operator by inserting
3184an 'i' in front of the name, e.g. __iadd__ implements in-place
3185__add__.
3186
3187Augmented assignment was implemented by Thomas Wouters.
3188
3189
3190List Comprehensions
3191-------------------
3192
3193This is a flexible new notation for lists whose elements are computed
3194from another list (or lists). The simplest form is:
3195
3196 [<expression> for <variable> in <sequence>]
3197
Guido van Rossum56db0952000-09-06 23:34:25 +00003198For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003199This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003200
3201You can also add a condition:
3202
3203 [<expression> for <variable> in <sequence> if <condition>]
3204
3205For example, [w for w in words if w == w.lower()] would yield the list
3206of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003207than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003208
3209You can also have nested for loops and more than one 'if' clause. For
3210example, here's a function that flattens a sequence of sequences::
3211
3212 def flatten(seq):
3213 return [x for subseq in seq for x in subseq]
3214
3215 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3216
3217This prints
3218
3219 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3220
3221List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003222Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003223
3224
3225Extended Import Statement
3226-------------------------
3227
3228Many people have asked for a way to import a module under a different
3229name. This can be accomplished like this:
3230
3231 import foo
3232 bar = foo
3233 del foo
3234
3235but this common idiom gets old quickly. A simple extension of the
3236import statement now allows this to be written as follows:
3237
3238 import foo as bar
3239
3240There's also a variant for 'from ... import':
3241
3242 from foo import bar as spam
3243
3244This also works with packages; e.g. you can write this:
3245
3246 import test.regrtest as regrtest
3247
3248Note that 'as' is not a new keyword -- it is recognized only in this
3249context (this is only possible because the syntax for the import
3250statement doesn't involve expressions).
3251
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003252Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003253
3254
3255Extended Print Statement
3256------------------------
3257
3258Easily the most controversial new feature, this extension to the print
3259statement adds an option to make the output go to a different file
3260than the default sys.stdout.
3261
3262For example, to write an error message to sys.stderr, you can now
3263write:
3264
3265 print >> sys.stderr, "Error: bad dog!"
3266
3267As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003268evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003269
3270 print >> None, "Hello world"
3271
3272is equivalent to
3273
3274 print "Hello world"
3275
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003276Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003277
3278
3279Optional Collection of Cyclical Garbage
3280---------------------------------------
3281
3282Python is now equipped with a garbage collector that can hunt down
3283cyclical references between Python objects. It's no replacement for
3284reference counting; in fact, it depends on the reference counts being
3285correct, and decides that a set of objects belong to a cycle if all
3286their reference counts can be accounted for from their references to
3287each other. This devious scheme was first proposed by Eric Tiedemann,
3288and brought to implementation by Neil Schemenauer.
3289
3290There's a module "gc" that lets you control some parameters of the
3291garbage collection. There's also an option to the configure script
3292that lets you enable or disable the garbage collection. In 2.0b1,
3293it's on by default, so that we (hopefully) can collect decent user
3294experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003295performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003296off by default in the final 2.0 release.
3297
3298
3299Smaller Changes
3300---------------
3301
3302A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3303map(None, seq1, seq2, ...) when the sequences have the same length;
3304i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3305the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003306zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003307
3308sys.version_info is a tuple (major, minor, micro, level, serial).
3309
3310Dictionaries have an odd new method, setdefault(key, default).
3311dict.setdefault(key, default) returns dict[key] if it exists; if not,
3312it sets dict[key] to default and returns that value. Thus:
3313
3314 dict.setdefault(key, []).append(item)
3315
3316does the same work as this common idiom:
3317
3318 if not dict.has_key(key):
3319 dict[key] = []
3320 dict[key].append(item)
3321
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003322There are two new variants of SyntaxError that are raised for
3323indentation-related errors: IndentationError and TabError.
3324
3325Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3326escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003327
3328The limits on the size of expressions and file in Python source code
3329have been raised from 2**16 to 2**32. Previous versions of Python
3330were limited because the maximum argument size the Python VM accepted
3331was 2**16. This limited the size of object constructor expressions,
3332e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3333limit was raised thanks to a patch by Charles Waldman that effectively
3334fixes the problem. It is now much more likely that you will be
3335limited by available memory than by an arbitrary limit in Python.
3336
3337The interpreter's maximum recursion depth can be modified by Python
3338programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3339limit is the maximum number of recursive calls that can be made by
3340Python code. The limit exists to prevent infinite recursion from
3341overflowing the C stack and causing a core dump. The default value is
33421000. The maximum safe value for a particular platform can be found
3343by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003344
3345New Modules and Packages
3346------------------------
3347
3348atexit - for registering functions to be called when Python exits.
3349
3350imputil - Greg Stein's alternative API for writing custom import
3351hooks.
3352
3353pyexpat - an interface to the Expat XML parser, contributed by Paul
3354Prescod.
3355
3356xml - a new package with XML support code organized (so far) in three
3357subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3358would fill a volume. There's a special feature whereby a
3359user-installed package named _xmlplus overrides the standard
3360xmlpackage; this is intended to give the XML SIG a hook to distribute
3361backwards-compatible updates to the standard xml package.
3362
3363webbrowser - a platform-independent API to launch a web browser.
3364
3365
Guido van Rossume905e952000-09-05 12:42:46 +00003366Changed Modules
3367---------------
3368
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003369array -- new methods for array objects: count, extend, index, pop, and
3370remove
3371
3372binascii -- new functions b2a_hex and a2b_hex that convert between
3373binary data and its hex representation
3374
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003375calendar -- Many new functions that support features including control
3376over which day of the week is the first day, returning strings instead
3377of printing them. Also new symbolic constants for days of week,
3378e.g. MONDAY, ..., SUNDAY.
3379
3380cgi -- FieldStorage objects have a getvalue method that works like a
3381dictionary's get method and returns the value attribute of the object.
3382
3383ConfigParser -- The parser object has new methods has_option,
3384remove_section, remove_option, set, and write. They allow the module
3385to be used for writing config files as well as reading them.
3386
3387ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003388optionally support the RFC 959 REST command.
3389
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003390gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003391
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003392httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3393the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003394
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003395locale -- implement getdefaultlocale for Win32 and Macintosh
3396
3397marshal -- no longer dumps core when marshaling deeply nested or
3398recursive data structures
3399
3400os -- new functions isatty, seteuid, setegid, setreuid, setregid
3401
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003402os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3403support under Unix.
3404
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003405os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003406
3407os.path -- fix semantics of os.path.commonprefix
3408
3409smtplib -- support for sending very long messages
3410
3411socket -- new function getfqdn()
3412
3413readline -- new functions to read, write and truncate history files.
3414The readline section of the library reference manual contains an
3415example.
3416
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003417select -- add interface to poll system call
3418
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003419shutil -- new copyfileobj function
3420
3421SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3422HTTP server.
3423
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003424Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003425
3426urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003427e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003428
3429whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003430
3431
3432Obsolete Modules
3433----------------
3434
3435None. However note that 1.6 made a whole slew of modules obsolete:
3436stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3437poly, zmod, strop, util, whatsound.
3438
3439
3440Changed, New, Obsolete Tools
3441----------------------------
3442
Tim Peters8b092332000-09-05 20:15:25 +00003443None.
Guido van Rossume905e952000-09-05 12:42:46 +00003444
3445
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003446C-level Changes
3447---------------
3448
3449Several cleanup jobs were carried out throughout the source code.
3450
3451All C code was converted to ANSI C; we got rid of all uses of the
3452Py_PROTO() macro, which makes the header files a lot more readable.
3453
3454Most of the portability hacks were moved to a new header file,
3455pyport.h; several other new header files were added and some old
3456header files were removed, in an attempt to create a more rational set
3457of header files. (Few of these ever need to be included explicitly;
3458they are all included by Python.h.)
3459
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003460Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003461and Win64, especially for the new Intel Itanium processor. Mick also
3462added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003463
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003464The C APIs to return an object's size have been update to consistently
3465use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3466previous versions, the abstract interfaces used PyXXX_Length and the
3467concrete interfaces used PyXXX_Size. The old names,
3468e.g. PyObject_Length, are still available for backwards compatibility
3469at the API level, but are deprecated.
3470
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003471The PyOS_CheckStack function has been implemented on Windows by
3472Fredrik Lundh. It prevents Python from failing with a stack overflow
3473on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003474
3475The GC changes resulted in creation of two new slots on object,
3476tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003477the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003478
3479The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003480C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003481
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003482PyErr_Format has been updated to automatically calculate the size of
3483the buffer needed to hold the formatted result string. This change
3484prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003485
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003486New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003487
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003488PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3489that are the same as their non-Ex counterparts except they take an
3490extra flag argument that tells them to close the file when done.
3491
3492XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003493
Tim Peters8b092332000-09-05 20:15:25 +00003494
3495Windows Changes
3496---------------
3497
3498New popen2/popen3/peopen4 in os module (see Changed Modules above).
3499
3500os.popen is much more usable on Windows 95 and 98. See Microsoft
3501Knowledge Base article Q150956. The Win9x workaround described there
3502is implemented by the new w9xpopen.exe helper in the root of your
3503Python installation. Note that Python uses this internally; it is not
3504a standalone program.
3505
3506Administrator privileges are no longer required to install Python
3507on Windows NT or Windows 2000. If you have administrator privileges,
3508Python's registry info will be written under HKEY_LOCAL_MACHINE.
3509Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003510under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003511uses of Python, but will prevent some advanced uses from working
3512(for example, running a Python script as an NT service, or possibly
3513from CGI).
3514
3515[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3516installer; instead, it installs the needed Tcl/Tk files directly in the
3517Python directory. If you already have a Tcl/Tk installation, this
3518wastes some disk space (about 4 Megs) but avoids problems with
3519conflicting Tcl/Tk installations, and makes it much easier for Python
3520to ensure that Tcl/Tk can find all its files.
3521
3522[This was new in 1.6] The Windows installer now installs by default in
3523\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3524
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003525
3526Updates to the changes between 1.5.2 and 1.6
3527--------------------------------------------
3528
3529The 1.6 NEWS file can't be changed after the release is done, so here
3530is some late-breaking news:
3531
3532New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3533and changes to getlocale() and setlocale().
3534
3535The new module is now enabled per default.
3536
3537It is not true that the encodings codecs cannot be used for normal
3538strings: the string.encode() (which is also present on 8-bit strings
3539!) allows using them for 8-bit strings too, e.g. to convert files from
3540cp1252 (Windows) to latin-1 or vice-versa.
3541
3542Japanese codecs are available from Tamito KAJIYAMA:
3543http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3544
3545
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003546======================================================================