blob: cc8115062abadce03f5610414c465a10676891f7 [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
Neal Norwitz649b7592002-01-01 19:07:13 +00009- file.xreadlines() now raises a ValueError if the file is closed:
10 Previously, an xreadlines object was returned which would raise
11 a ValueError when the xreadlines.next() method was called.
12
Tim Petersaf8446f2001-12-21 21:36:50 +000013Extension modules
14
Neal Norwitze790eae2002-01-01 21:14:12 +000015- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000016 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
17 is called.
18
Tim Petersaf8446f2001-12-21 21:36:50 +000019Library
20
Guido van Rossum606fe4e2001-12-28 20:57:14 +000021- ftplib: to safeguard the user's privacy, anonymous login will use
22 "anonymous@" as default password, rather than the real user and host
23 name.
24
Fred Drake36736122002-01-10 13:50:31 +000025- webbrowser: tightened up the command passed to os.system() so that
26 arbitrary shell code can't be executed because a bogus URL was
27 passed in.
28
Martin v. Löwis1be64192002-01-11 06:33:28 +000029- gettext.translation has an optional fallback argument.
30
Tim Petersaf8446f2001-12-21 21:36:50 +000031Tools/Demos
32
33Build
34
35C API
36
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000037- The "u#" parser marker will now pass through Unicode object as-is
38 without going through the buffer API.
39
Martin v. Löwis7198a522002-01-01 19:59:11 +000040- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
41
Tim Peters10a3bb52001-12-25 19:07:38 +000042- An old #define of ANY as void has been removed from pyport.h. This
43 hasn't been used since Python's pre-ANSI days, and the #define has
44 been marked as obsolete since then. SF bug 495548 says it created
45 conflicts with other packages, so keeping it around wasn't harmless.
46
Tim Petersaf8446f2001-12-21 21:36:50 +000047- Because Python's magic number scheme broke on January 1st, we decided
48 to stop Python development. Thanks for all the fish!
49
50New platforms
51
Martin v. Löwisa6e97582002-01-01 18:41:33 +000052- GNU/Hurd is now supported.
53
Tim Petersaf8446f2001-12-21 21:36:50 +000054Tests
55
56Windows
57
58Mac
59
60
Tim Peters909c0912001-12-14 23:16:18 +000061What's New in Python 2.2 final?
62Release date: 21-Dec-2001
63===============================
64
65Type/class unification and new-style classes
66
Barry Warsaw52acb492001-12-21 20:04:22 +000067- pickle.py, cPickle: allow pickling instances of new-style classes
68 with a custom metaclass.
69
Tim Peters909c0912001-12-14 23:16:18 +000070Core and builtins
71
Barry Warsaw52acb492001-12-21 20:04:22 +000072- weakref proxy object: when comparing, unwrap both arguments if both
73 are proxies.
74
Tim Peters909c0912001-12-14 23:16:18 +000075Extension modules
76
Barry Warsaw52acb492001-12-21 20:04:22 +000077- binascii.b2a_base64(): fix a potential buffer overrun when encoding
78 very short strings.
79
80- cPickle: the obscure "fast" mode was suspected of causing stack
81 overflows on the Mac. Hopefully fixed this by setting the recursion
82 limit much smaller. If the limit is too low (it only affects
83 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
84 when compiling cPickle.c (or in pyconfig.h).
85
Tim Peters909c0912001-12-14 23:16:18 +000086Library
87
Barry Warsaw52acb492001-12-21 20:04:22 +000088- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
89 close or delete time).
90
91- rfc822.py: fixed a bug where the address '<>' was converted to None
92 instead of an empty string (also fixes the email.Utils module).
93
94- xmlrpclib.py: version 1.0.0; uses precision for doubles.
95
96- test suite: the pickle and cPickle tests were not executing any code
97 when run from the standard regresssion test.
98
Tim Peters909c0912001-12-14 23:16:18 +000099Tools/Demos
100
101Build
102
103C API
104
105New platforms
106
107Tests
108
109Windows
110
Barry Warsaw52acb492001-12-21 20:04:22 +0000111- distutils package: fixed broken Windows installers (bdist_wininst).
112
113- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
114 instances are deleted at process exit time.
115
116- socket.py: prevent mysterious warnings when socket instances are
117 deleted at process exit time.
118
119- posixmodule.c: fix a Windows crash with stat() of a filename ending
120 in backslash.
121
Tim Peters909c0912001-12-14 23:16:18 +0000122Mac
123
Barry Warsaw52acb492001-12-21 20:04:22 +0000124- The Carbon toolbox modules have been upgraded to Universal Headers
125 3.4, and experimental CoreGraphics and CarbonEvents modules have
126 been added. All only for framework-enabled MacOSX.
127
Tim Peters909c0912001-12-14 23:16:18 +0000128
Tim Peters6272dfd2001-12-13 19:34:00 +0000129What's New in Python 2.2c1?
130Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000131===========================
132
133Type/class unification and new-style classes
134
Barry Warsaw06557452001-12-14 20:47:12 +0000135- Guido's tutorial introduction to the new type/class features has
136 been extensively updated. See
137
138 http://www.python.org/2.2/descrintro.html
139
140 That remains the primary documentation in this area.
141
Guido van Rossum33bab012001-12-05 22:45:48 +0000142- Fixed a leak: instance variables declared with __slots__ were never
143 deleted!
144
Guido van Rossum4b800852001-12-03 00:54:52 +0000145- The "delete attribute" method of descriptor objects is called
146 __delete__, not __del__. In previous releases, it was mistakenly
147 called __del__, which created an unfortunate overloading condition
148 with finalizers. (The "get attribute" and "set attribute" methods
149 are still called __get__ and __set__, respectively.)
150
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000151- Some subtle issues with the super built-in were fixed:
152
153 (a) When super itself is subclassed, its __get__ method would still
154 return an instance of the base class (i.e., of super).
155
156 (b) super(C, C()).__class__ would return C rather than super. This
157 is confusing. To fix this, I decided to change the semantics of
158 super so that it only applies to code attributes, not to data
159 attributes. After all, overriding data attributes is not
160 supported anyway.
161
162 (c) The __get__ method didn't check whether the argument was an
163 instance of the type used in creation of the super instance.
164
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000165- Previously, hash() of an instance of a subclass of a mutable type
166 (list or dictionary) would return some value, rather than raising
167 TypeError. This has been fixed. Also, directly calling
168 dict.__hash__ and list.__hash__ now raises the same TypeError
169 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000170
Guido van Rossumd331cb52001-12-05 19:46:42 +0000171- New-style objects now support deleting their __dict__. This is for
172 all intents and purposes equivalent to assigning a brand new empty
173 dictionary, but saves space if the object is not used further.
174
Tim Petersb3c9af12001-11-17 00:21:57 +0000175Core and builtins
176
Tim Peters3caca232001-12-06 06:23:26 +0000177- -Qnew now works as documented in PEP 238: when -Qnew is passed on
178 the command line, all occurrences of "/" use true division instead
179 of classic division. See the PEP for details. Note that "all"
180 means all instances in library and 3rd-party modules, as well as in
181 your own code. As the PEP says, -Qnew is intended for use only in
182 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000183 Note that test_coercion.py in the standard Python test suite fails
184 under -Qnew; this is expected, and won't be repaired until true
185 division becomes the default (in the meantime, test_coercion is
186 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000187
Fred Drake6c01e252001-12-14 17:08:12 +0000188- complex() now only allows the first argument to be a string
189 argument, and raises TypeError if either the second arg is a string
190 or if the second arg is specified when the first is a string.
191
Tim Petersb3c9af12001-11-17 00:21:57 +0000192Extension modules
193
Martin v. Löwis560da622001-11-24 09:24:51 +0000194- gc.get_referents was renamed to gc.get_referrers.
195
Tim Petersb3c9af12001-11-17 00:21:57 +0000196Library
197
Tim Peters25059d32001-12-07 20:35:43 +0000198- Functions in the os.spawn() family now release the global interpreter
199 lock around calling the platform spawn. They should always have done
200 this, but did not before 2.2c1. Multithreaded programs calling
201 an os.spawn function with P_WAIT will no longer block all Python threads
202 until the spawned program completes. It's possible that some programs
203 relies on blocking, although more likely by accident than by design.
204
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000205- webbrowser defaults to netscape.exe on OS/2 now.
206
Martin v. Löwis652e1912001-11-25 14:50:56 +0000207- Tix.ResizeHandle exposes detach_widget, hide, and show.
208
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000209- The charset alias windows_1252 has been added.
210
Barry Warsaw06557452001-12-14 20:47:12 +0000211- types.StringTypes is a tuple containing the defined string types;
212 usually this will be (str, unicode), but if Python was compiled
213 without Unicode support it will be just (str,).
214
215- The pulldom and minidom modules were synchronized to PyXML.
216
Tim Petersb3c9af12001-11-17 00:21:57 +0000217Tools/Demos
218
Barry Warsaw06557452001-12-14 20:47:12 +0000219- A new script called Tools/scripts/google.py was added, which fires
220 off a search on Google.
221
Tim Petersb3c9af12001-11-17 00:21:57 +0000222Build
223
Barry Warsaw06557452001-12-14 20:47:12 +0000224- Note that release builds of Python should arrange to define the
225 preprocessor symbol NDEBUG on the command line (or equivalent).
226 In the 2.2 pre-release series we tried to define this by magic in
227 Python.h instead, but it proved to cause problems for extension
228 authors. The Unix, Windows and Mac builds now all define NDEBUG in
229 release builds via cmdline (or equivalent) instead. Ports to
230 other platforms should do likewise.
231
Jack Jansen1999ef42001-12-06 21:47:20 +0000232- It is no longer necessary to use --with-suffix when building on a
233 case-insensitive file system (such as Mac OS X HFS+). In the build
234 directory an extension is used, but not in the installed python.
235
Tim Petersb3c9af12001-11-17 00:21:57 +0000236C API
237
Tim Petersf582b822001-12-11 18:51:08 +0000238- New function PyDict_MergeFromSeq2() exposes the builtin dict
239 constructor's logic for updating a dictionary from an iterable object
240 producing key-value pairs.
241
Tim Peterscffed4b2001-11-29 03:26:37 +0000242- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000243 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000244 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
245 dump core in some bad cases. This has been repaired. As a result,
246 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
247 previously went unchallenged.
248
Tim Petersb3c9af12001-11-17 00:21:57 +0000249New platforms
250
251Tests
252
253Windows
254
255Mac
256
Jack Jansenffa260f2001-12-06 21:14:00 +0000257- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
258 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000259
Barry Warsaw06557452001-12-14 20:47:12 +0000260- Changed logic for finding python home in Mac OS X framework Pythons.
261 Now sys.executable points to the executable again, in stead of to
262 the shared library. The latter is used only for locating the python
263 home.
264
265
Tim Peters84362bc2001-10-19 17:55:30 +0000266What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000267Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000268===========================
269
270Type/class unification and new-style classes
271
Guido van Rossum3d27df02001-11-15 20:27:54 +0000272- Multiple inheritance mixing new-style and classic classes in the
273 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000274
275 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000276 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000277
278 The MRO (method resolution order) for each base class is respected
279 according to its kind, but the MRO for the derived class is computed
280 using new-style MRO rules if any base clase is a new-style class.
281 This needs to be documented.
282
Tim Petersa427a2b2001-10-29 22:25:45 +0000283- The new builtin dictionary() constructor, and dictionary type, have
284 been renamed to dict. This reflects a decade of common usage.
285
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000286- dict() now accepts an iterable object producing 2-sequences. For
287 example, dict(d.items()) == d for any dictionary d. The argument,
288 and the elements of the argument, can be any iterable objects.
289
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000290- New-style classes can now have a __del__ method, which is called
291 when the instance is deleted (just like for classic classes).
292
Guido van Rossum12d955c2001-10-26 14:56:06 +0000293- Assignment to object.__dict__ is now possible, for objects that are
294 instances of new-style classes that have a __dict__ (unless the base
295 class forbids it).
296
Guido van Rossumc8e56452001-10-22 00:43:43 +0000297- Methods of built-in types now properly check for keyword arguments
298 (formerly these were silently ignored). The only built-in methods
299 that take keyword arguments are __call__, __init__ and __new__.
300
Guido van Rossum86443212001-10-27 22:28:54 +0000301- The socket function has been converted to a type; see below.
302
Tim Peters84362bc2001-10-19 17:55:30 +0000303Core and builtins
304
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000305- Assignment to __debug__ raises SyntaxError at compile-time. This
306 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000307 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000308
Guido van Rossum12d955c2001-10-26 14:56:06 +0000309- Clarified the error messages for unsupported operands to an operator
310 (like 1 + '').
311
Tim Peters84362bc2001-10-19 17:55:30 +0000312Extension modules
313
Tim Peters5ebfd362001-11-13 23:11:19 +0000314- mmap has a new keyword argument, "access", allowing a uniform way for
315 both Windows and Unix users to create read-only, write-through and
316 copy-on-write memory mappings. This was previously possible only on
317 Unix. A new keyword argument was required to support this in a
318 uniform way because the mmap() signuatures had diverged across
319 platforms. Thanks to Jay T Miller for repairing this!
320
Tim Peters169ded02001-11-03 19:57:21 +0000321- By default, the gc.garbage list now contains only those instances in
322 unreachable cycles that have __del__ methods; in 2.1 it contained all
323 instances in unreachable cycles. "Instances" here has been generalized
324 to include instances of both new-style and old-style classes.
325
Guido van Rossum12d955c2001-10-26 14:56:06 +0000326- The socket module defines a new method for socket objects,
327 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000328 send() until all data has been sent. Also, the socket function has
329 been converted to a subclassable type, like list and tuple (etc.)
330 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000331
332- Various bugfixes to the curses module. There is now a test suite
333 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000334
Guido van Rossum692adf12001-10-30 03:03:03 +0000335- binascii.b2a_base64 no longer places an arbitrary restriction of 57
336 bytes on its input.
337
Tim Peters84362bc2001-10-19 17:55:30 +0000338Library
339
Tim Peters5ebfd362001-11-13 23:11:19 +0000340- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000341 convenience function.
342
Tim Peters75335872001-11-03 19:35:43 +0000343- Symbolic group names in regular expressions must be unique. For
344 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
345 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000346 Python 2.2 detects this error at regexp compilation time;
347 previously, the error went undetected, and results were
348 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
349 pattern.subn() methods have been rewritten in C. Also, an
350 experimental function/method finditer() has been added, which works
351 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000352
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000353- Tix exposes more commands through the classes DirSelectBox,
354 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
355 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
356 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
357
Tim Peters98791af2001-10-23 01:59:54 +0000358- Traceback objects are now scanned by cyclic garbage collection, so
359 cycles created by casual use of sys.exc_info() no longer cause
360 permanent memory leaks (provided garbage collection is enabled).
361
Guido van Rossum49192142001-10-24 20:51:44 +0000362- os.extsep -- a new variable needed by the RISCOS support. It is the
363 separator used by extensions, and is '.' on all platforms except
364 RISCOS, where it is '/'. There is no need to use this variable
365 unless you have a masochistic desire to port your code to RISCOS.
366
Barry Warsaw012852b2001-11-16 16:17:27 +0000367- mimetypes.py has optional support for non-standard, but commonly
368 found types. guess_type() and guess_extension() now accept an
369 optional `strict' flag, defaulting to true, which controls whether
370 recognize non-standard types or not. A few non-standard types we
371 know about have been added. Also, when run as a script, there are
372 new -l and -e options.
373
374- statcache is now deprecated.
375
376- email.Utils.formatdate() now produces the preferred RFC 2822 style
377 dates with numeric timezones (it used to produce obsolete dates
378 hard coded to "GMT" timezone). An optional `localtime' flag is
379 added to produce dates in the local timezone, with daylight savings
380 time properly taken into account.
381
382- In pickle and cPickle, instead of masking errors in load() by
383 transforming them into SystemError, we let the original exception
384 propagate out. Also, implement support for __safe_for_unpickling__
385 in pickle, as it already was supported in cPickle.
386
Tim Peters84362bc2001-10-19 17:55:30 +0000387Tools/Demos
388
389Build
390
Barry Warsaw012852b2001-11-16 16:17:27 +0000391- The dbm module is built using libdb1 if available. The bsddb module
392 is built with libdb3 if available.
393
394- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
395
Tim Peters84362bc2001-10-19 17:55:30 +0000396C API
397
Tim Peters1fc240e2001-10-26 05:06:50 +0000398- New function PySequence_Fast_GET_SIZE() returns the size of a non-
399 NULL result from PySequence_Fast(), more quickly than calling
400 PySequence_Size().
401
Barry Warsaw012852b2001-11-16 16:17:27 +0000402- New argument unpacking function PyArg_UnpackTuple() added.
403
404- New functions PyObject_CallFunctionObjArgs() and
405 PyObject_CallMethodObjArgs() have been added to make it more
406 convenient and efficient to call functions and methods from C.
407
408- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
409 possible that this will propagate errors it didn't before.
410
411- New function PyObject_CheckReadBuffer(), which returns true if its
412 argument supports the single-segment readable buffer interface.
413
Tim Peters84362bc2001-10-19 17:55:30 +0000414New platforms
415
Guido van Rossum86443212001-10-27 22:28:54 +0000416- We've finally confirmed that this release builds on HP-UX 11.00,
417 *with* threads, and passes the test suite.
418
Tim Peters7a33d8b2001-11-05 02:51:07 +0000419- Thanks to a series of patches from Michael Muller, Python may build
420 again under OS/2 Visual Age C++.
421
Guido van Rossum49192142001-10-24 20:51:44 +0000422- Updated RISCOS port by Dietmar Schwertberger.
423
Tim Peters84362bc2001-10-19 17:55:30 +0000424Tests
425
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000426- Added a test script for the curses module. It isn't run automatically;
427 regrtest.py must be run with '-u curses' to enable it.
428
Tim Peters84362bc2001-10-19 17:55:30 +0000429Windows
430
Barry Warsaw012852b2001-11-16 16:17:27 +0000431Mac
432
433- PythonScript has been moved to unsupported and is slated to be
434 removed completely in the next release.
435
436- It should now be possible to build applets that work on both OS9 and
437 OSX.
438
439- The core is now linked with CoreServices not Carbon; as a side
440 result, default 8bit encoding on OSX is now ASCII.
441
442- Python should now build on OSX 10.1.1
443
Tim Peters84362bc2001-10-19 17:55:30 +0000444
Tim Petersabf925f2001-09-28 21:53:42 +0000445What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000446Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000447===========================
448
449Type/class unification and new-style classes
450
Guido van Rossum687ae002001-10-15 22:03:32 +0000451- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000452 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000453 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000454 remains: the __dict__ of a new-style class is a read-only proxy; you
455 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000456 __defined__ attribute of new-style types no longer exists, for lack
457 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000458 future a __cache__ may be resurrected with a similar function, if I
459 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000460
Tim Peters1c9ca872001-10-04 06:43:12 +0000461- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
462 always returned None, even when there was a class docstring).
463
464- doctest now finds and runs docstrings attached to new-style classes,
465 class methods, static methods, and properties.
466
Guido van Rossum9074ef62001-10-16 21:34:49 +0000467Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000468
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000469- A very subtle syntactical pitfall in list comprehensions was fixed.
470 For example: [a+b for a in 'abc', for b in 'def']. The comma in
471 this example is a mistake. Previously, this would silently let 'a'
472 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
473 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
474 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
475 Note that [a for a in <singleton>] is a convoluted way to say
476 [<singleton>] anyway, so it's not like any expressiveness is lost.
477
Guido van Rossum9074ef62001-10-16 21:34:49 +0000478- getattr(obj, name, default) now only catches AttributeError, as
479 documented, rather than returning the default value for all
480 exceptions (which could mask bugs in a __getattr__ hook, for
481 example).
482
Fred Drakecb7a6b52001-10-22 18:41:51 +0000483- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000484 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000485 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000486 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000487
Guido van Rossum1c486092001-10-19 02:05:35 +0000488- unicode(obj) now behaves more like str(obj), accepting arbitrary
489 objects, and calling a __unicode__ method if it exists.
490 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000491 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000492
Barry Warsawf6fb1712001-10-19 05:35:40 +0000493- isinstance() now allows any object as the first argument and a
494 class, a type or something with a __bases__ tuple attribute for the
495 second argument. The second argument may also be a tuple of a
496 class, type, or something with __bases__, in which case isinstance()
497 will return true if the first argument is an instance of any of the
498 things contained in the second argument tuple. E.g.
499
500 isinstance(x, (A, B))
501
502 returns true if x is an instance of A or B.
503
Guido van Rossum9074ef62001-10-16 21:34:49 +0000504Extension modules
505
506- thread.start_new_thread() now returns the thread ID (previously None).
507
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000508- binascii has now two quopri support functions, a2b_qp and b2a_qp.
509
Guido van Rossumc524d952001-10-19 01:31:59 +0000510- readline now supports setting the startup_hook and the
511 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000512
Guido van Rossumc524d952001-10-19 01:31:59 +0000513- os and posix supports chroot(), setgroups() and unsetenv() where
514 available. The stat(), fstat(), statvfs() and fstatvfs() functions
515 now return "pseudo-sequences" -- the various fields can now be
516 accessed as attributes (e.g. os.stat("/").st_mtime) but for
517 backwards compatibility they also behave as a fixed-length sequence.
518 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000519 attributes.
520
521- time: localtime(), gmtime() and strptime() now return a
522 pseudo-sequence similar to the os.stat() return value, with
523 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000524
Guido van Rossum9074ef62001-10-16 21:34:49 +0000525- Decompression objects in the zlib module now accept an optional
526 second parameter to decompress() that specifies the maximum amount
527 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000528
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000529- optional SSL support in the socket module now exports OpenSSL
530 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
531 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000532 automatically seed its PRNG. Also, the keyfile and certfile
533 arguments to socket.ssl() are now optional.
534
535- posixmodule (and by extension, the os module on POSIX platforms) now
536 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000537
Guido van Rossum9074ef62001-10-16 21:34:49 +0000538Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000539
Tim Peters7402f792001-10-02 03:53:41 +0000540- doctest now excludes functions and classes not defined by the module
541 being tested, thanks to Tim Hochberg.
542
Fred Drakecb7a6b52001-10-22 18:41:51 +0000543- HotShot, a new profiler implemented using a C-based callback, has
544 been added. This substantially reduces the overhead of profiling,
545 but it is still quite preliminary. Support modules and
546 documentation will be added in upcoming releases (before 2.2 final).
547
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000548- profile now produces correct output in situations where an exception
549 raised in Python is cleared by C code (e.g. hasattr()). This used
550 to cause wrong output, including spurious claims of recursive
551 functions and attribution of time spent to the wrong function.
552
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000553 The code and documentation for the derived OldProfile and HotProfile
554 profiling classes was removed. The code hasn't worked for years (if
555 you tried to use them, they raised exceptions). OldProfile
556 intended to reproduce the behavior of the profiler Python used more
557 than 7 years ago, and isn't interesting anymore. HotProfile intended
558 to provide a faster profiler (but producing less information), and
559 that's a worthy goal we intend to meet via a different approach (but
560 without losing information).
561
Tim Peterscce092d2001-10-09 05:31:56 +0000562- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000563 a much better system-specific calibration constant. The constant can
564 now be specified in an instance constructor, or as a Profile class or
565 instance variable, instead of by editing profile.py's source code.
566 Calibration must still be done manually (see the docs for the profile
567 module).
568
569 Note that Profile.calibrate() must be overriden by subclasses.
570 Improving the accuracy required exploiting detailed knowledge of
571 profiler internals; the earlier method abstracted away the details
572 and measured a simplified model instead, but consequently computed
573 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000574
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000575- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000576 which indicates whether output is intended for the header 'Q'
577 encoding.
578
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000579- The SocketServer.ThreadingMixIn class now closes the request after
580 finish_request() returns. (Not when it errors out though.)
581
Barry Warsawf6fb1712001-10-19 05:35:40 +0000582- The nntplib module's NNTP.body() method has grown a `file' argument
583 to allow saving the message body to a file.
584
585- The email package has added a class email.Parser.HeaderParser which
586 only parses headers and does not recurse into the message's body.
587 Also, the module/class MIMEAudio has been added for representing
588 audio data (contributed by Anthony Baxter).
589
590- ftplib should be able to handle files > 2GB.
591
592- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
593 ON, and OFF.
594
Fred Drakecb7a6b52001-10-22 18:41:51 +0000595- xml.dom.minidom NodeList objects now support the length attribute
596 and item() method as required by the DOM specifications.
597
Guido van Rossumed554f62001-10-02 23:15:37 +0000598Tools/Demos
599
600- Demo/dns was removed. It no longer serves any purpose; a package
601 derived from it is now maintained by Anthony Baxter, see
602 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000603
Barry Warsawf6fb1712001-10-19 05:35:40 +0000604- The freeze tool has been made more robust, and two new options have
605 been added: -X and -E.
606
Tim Petersabf925f2001-09-28 21:53:42 +0000607Build
608
Barry Warsawf6fb1712001-10-19 05:35:40 +0000609- configure will use CXX in LINKCC if CXX is used to build main() and
610 the system requires to link a C++ main using the C++ compiler.
611
Tim Petersabf925f2001-09-28 21:53:42 +0000612C API
613
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000614- The documentation for the tp_compare slot is updated to require that
615 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
616 not correct. This is not yet enforced but will be enforced in
617 Python 2.3; even later, we may use -2 to indicate errors and +2 for
618 "NotImplemented". Right now, -1 should be used for an error return.
619
Tim Petersd38b1c72001-09-30 05:09:37 +0000620- PyLong_AsLongLong() now accepts int (as well as long) arguments.
621 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
622 as long) arguments.
623
Guido van Rossum3c288632001-10-16 21:13:49 +0000624- PyThread_start_new_thread() now returns a long int giving the thread
625 ID, if one can be calculated; it returns -1 for error, 0 if no
626 thread ID is calculated (this is an incompatible change, but only
627 the thread module used this API). This code has only really been
628 tested on Linux and Windows; other platforms please beware (and
629 report any bugs or strange behavior).
630
Guido van Rossum1c486092001-10-19 02:05:35 +0000631- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
632 input.
633
Tim Petersabf925f2001-09-28 21:53:42 +0000634New platforms
635
636Tests
637
638Windows
639
Tim Peters04cf1d32001-10-09 22:39:40 +0000640- Installer: If you install IDLE, and don't disable file-extension
641 registration, a new "Edit with IDLE" context (right-click) menu entry
642 is created for .py and .pyw files.
643
Tim Peters1ce3cf72001-10-01 17:58:40 +0000644- The signal module now supports SIGBREAK on Windows, thanks to Steven
645 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
646 action remains to call Win32 ExitProcess(). This can be changed via
647 signal.signal(). For example:
648
649 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
650 # (SIGINT) behavior.
651 import signal
652 signal.signal(signal.SIGBREAK,
653 signal.default_int_handler)
654
655 try:
656 while 1:
657 pass
658 except KeyboardInterrupt:
659 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
660 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
661 # program without the possibility for any Python-level cleanup).
662 print "Clean exit"
663
Tim Petersabf925f2001-09-28 21:53:42 +0000664
Tim Petersb07352e2001-09-08 01:25:47 +0000665What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000666Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000667===========================
668
Guido van Rossum808eea72001-09-25 04:15:41 +0000669Type/class unification and new-style classes
670
671- pydoc and inspect are now aware of new-style classes;
672 e.g. help(list) at the interactive prompt now shows proper
673 documentation for all operations on list objects.
674
675- Applications using Jim Fulton's ExtensionClass module can now safely
676 be used with Python 2.2. In particular, Zope 2.4.1 now works with
677 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
678 examples also work again. It is hoped that Gtk and Boost also work
679 with 2.2a4 and beyond. (If you can confirm this, please write
680 webmaster@python.org; if there are still problems, please open a bug
681 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000682
Tim Peters66c1a522001-09-24 21:17:50 +0000683- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
684 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
685 in the constructed property object. fget, fset and fdel weren't
686 discoverable from Python in 2.2a3. __doc__ is new, and allows to
687 associate a docstring with a property.
688
Guido van Rossum808eea72001-09-25 04:15:41 +0000689- Comparison overloading is now more completely implemented. For
690 example, a str subclass instance can properly be compared to a str
691 instance, and it can properly overload comparison. Ditto for most
692 other built-in object types.
693
694- The repr() of new-style classes has changed; instead of <type
695 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
696 *except* for built-in types, which are still rendered as <type
697 'Foo'> (to avoid upsetting existing code that might parse or
698 otherwise rely on repr() of certain type objects).
699
700- The repr() of new-style objects is now always <Foo object at XXX>;
701 previously, it was sometimes <Foo instance at XXX>.
702
703- For new-style classes, what was previously called __getattr__ is now
704 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000705 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000706 one in classic classes is defined which is called only if regular
707 attribute access raises AttributeError; to catch *all* attribute
708 access, you can use __getattribute__ (for new-style classes). If
709 both are defined, __getattribute__ is called first, and if it raises
710 AttributeError, __getattr__ is called.
711
712- The __class__ attribute of new-style objects can be assigned to.
713 The new class must have the same C-level object layout as the old
714 class.
715
716- The builtin file type can be subclassed now. In the usual pattern,
717 "file" is the name of the builtin type, and file() is a new builtin
718 constructor, with the same signature as the builtin open() function.
719 file() is now the preferred way to open a file.
720
721- Previously, __new__ would only see sequential arguments passed to
722 the type in a constructor call; __init__ would see both sequential
723 and keyword arguments. This made no sense whatsoever any more, so
724 now both __new__ and __init__ see all arguments.
725
726- Previously, hash() applied to an instance of a subclass of str or
727 unicode always returned 0. This has been repaired.
728
729- Previously, an operation on an instance of a subclass of an
730 immutable type (int, long, float, complex, tuple, str, unicode),
731 where the subtype didn't override the operation (and so the
732 operation was handled by the builtin type), could return that
733 instance instead a value of the base type. For example, if s was of
734 a str sublass type, s[:] returned s as-is. Now it returns a str
735 with the same value as s.
736
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000737- Provisional support for pickling new-style objects has been added.
738
Guido van Rossum808eea72001-09-25 04:15:41 +0000739Core
740
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000741- file.writelines() now accepts any iterable object producing strings.
742
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000743- PyUnicode_FromEncodedObject() now works very much like
744 PyObject_Str(obj) in that it tries to use __str__/tp_str
745 on the object if the object is not a string or buffer. This
746 makes unicode() behave like str() when applied to non-string/buffer
747 objects.
748
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000749- PyFile_WriteObject now passes Unicode objects to the file's write
750 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000751 of a print statement must support Unicode objects, i.e. they must
752 at least convert them into ASCII strings.
753
Guido van Rossum624c8af2001-09-18 15:21:04 +0000754- Thread scheduling on Solaris should be improved; it is no longer
755 necessary to insert a small sleep at the start of a thread in order
756 to let other runnable threads be scheduled.
757
Tim Petersb07352e2001-09-08 01:25:47 +0000758Library
759
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000760- StringIO.StringIO instances and cStringIO.StringIO instances support
761 read character buffer compatible objects for their .write() methods.
762 These objects are converted to strings and then handled as such
763 by the instances.
764
Barry Warsaw2f600732001-09-24 04:28:10 +0000765- The "email" package has been added. This is basically a port of the
766 mimelib package <http://sf.net/projects/mimelib> with API changes
767 and some implementations updated to use iterators and generators.
768
Tim Peters8a9c2842001-09-22 21:30:22 +0000769- difflib.ndiff() and difflib.Differ.compare() are generators now. This
770 restores the ability of Tools/scripts/ndiff.py to start producing output
771 before the entire comparison is complete.
772
Barry Warsaw58b072d2001-09-22 04:44:21 +0000773- StringIO.StringIO instances and cStringIO.StringIO instances support
774 iteration just like file objects (i.e. their .readline() method is
775 called for each iteration until it returns an empty string).
776
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000777- The codecs module has grown four new helper APIs to access
778 builtin codecs: getencoder(), getdecoder(), getreader(),
779 getwriter().
780
Guido van Rossum624c8af2001-09-18 15:21:04 +0000781- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
782 simplifies writing XML RPC servers.
783
Barry Warsaw647d5e82001-09-28 17:01:02 +0000784- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000785 after interpretation of symbolic links. On non-Unix systems, this
786 is an alias for os.path.abspath().
787
Tim Peters16a77ad2001-09-08 04:00:12 +0000788- operator.indexOf() (PySequence_Index() in the C API) now works with any
789 iterable object.
790
Guido van Rossum624c8af2001-09-18 15:21:04 +0000791- smtplib now supports various authentication and security features of
792 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000793
Guido van Rossum624c8af2001-09-18 15:21:04 +0000794- hmac: a new module implementing keyed hashing for message
795 authentication.
796
797- mimetypes now recognizes more extensions and file types. At the
798 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000799
Guido van Rossum624c8af2001-09-18 15:21:04 +0000800- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000801 Python 2.2 bytecode generation. It has also been promoted from a
802 Tool to a standard library package. (Tools/compiler still exists as
803 a sample driver.)
804
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000805Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000806
Tim Petersb07352e2001-09-08 01:25:47 +0000807Build
808
Guido van Rossum624c8af2001-09-18 15:21:04 +0000809- Large file support (LFS) is now automatic when the platform supports
810 it; no more manual configuration tweaks are needed. On Linux, at
811 least, it's possible to have a system whose C library supports large
812 files but whose kernel doesn't; in this case, large file support is
813 still enabled but doesn't do you any good unless you upgrade your
814 kernel or share your Python executable with another system whose
815 kernel has large file support.
816
817- The configure script now supplies plausible defaults in a
818 cross-compilation environment. This doesn't mean that the supplied
819 values are always correct, or that cross-compilation now works
820 flawlessly -- but it's a first step (and it shuts up most of
821 autoconf's warnings about AC_TRY_RUN).
822
823- The Unix build is now a bit less chatty, courtesy of the parser
824 generator. The build is completely silent (except for errors) when
825 using "make -s", thanks to a -q option to setup.py.
826
Tim Petersb07352e2001-09-08 01:25:47 +0000827C API
828
Guido van Rossum624c8af2001-09-18 15:21:04 +0000829- The "structmember" API now supports some new flag bits to deny read
830 and/or write access to attributes in restricted execution mode.
831
Tim Petersb07352e2001-09-08 01:25:47 +0000832New platforms
833
Guido van Rossum624c8af2001-09-18 15:21:04 +0000834- Compaq's iPAQ handheld, running the "familiar" Linux distribution
835 (http://familiar.handhelds.org).
836
Tim Petersb07352e2001-09-08 01:25:47 +0000837Tests
838
Tim Peters8a9c2842001-09-22 21:30:22 +0000839- The "classic" standard tests, which work by comparing stdout to
840 an expected-output file under Lib/test/output/, no longer stop at
841 the first mismatch. Instead the test is run to completion, and a
842 variant of ndiff-style comparison is used to report all differences.
843 This is much easier to understand than the previous style of reporting.
844
845- The unittest-based standard tests now use regrtest's test_main()
846 convention, instead of running as a side-effect of merely being
847 imported. This allows these tests to be run in more natural and
848 flexible ways as unittests, outside the regrtest framework.
849
850- regrtest.py is much better integrated with unittest and doctest now,
851 especially in regard to reporting errors.
852
Tim Petersb07352e2001-09-08 01:25:47 +0000853Windows
854
Guido van Rossum624c8af2001-09-18 15:21:04 +0000855- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000856 that support it (NTFS under Windows 2000). See "What's New in
857 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000858
Tim Petersb07352e2001-09-08 01:25:47 +0000859
Tim Petersedc99312001-08-22 21:36:50 +0000860What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000861Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000862===========================
863
864Core
865
Tim Peters9fffa3e2001-09-04 05:14:19 +0000866- Conversion of long to float now raises OverflowError if the long is too
867 big to represent as a C double.
868
Tim Peters32f453e2001-09-03 08:35:41 +0000869- The 3-argument builtin pow() no longer allows a third non-None argument
870 if either of the first two arguments is a float, or if both are of
871 integer types and the second argument is negative (in which latter case
872 the arguments are converted to float, so this is really the same
873 restriction).
874
Tim Peters5d2b77c2001-09-03 05:47:38 +0000875- The builtin dir() now returns more information, and sometimes much
876 more, generally naming all attributes of an object, and all attributes
877 reachable from the object via its class, and from its class's base
878 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
879 an empty list. In 2.2a3,
880
881 >>> dir([])
882 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
883 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
884 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
885 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
886 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
887 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
888 'reverse', 'sort']
889
890 dir(module) continues to return only the module's attributes, though.
891
Tim Petersbdee63f2001-09-02 03:40:59 +0000892- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000893 than raising OverflowError. This is a partial implementation of PEP
894 237. You can use -Wdefault::OverflowWarning to enable a warning for
895 this situation, and -Werror::OverflowWarning to revert to the old
896 OverflowError exception.
897
Guido van Rossum61c345f2001-09-04 03:26:15 +0000898- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000899 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000900 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
901 -Qold, meaning the / operator has its classic meaning and no
902 warnings are issued. Using -Qwarn issues a run-time warning about
903 all uses of classic division for int and long arguments; -Qwarnall
904 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000905 (for use with fixdiv.py).
906 [Note: the remainder of this paragraph (preserved below) became
907 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
908 <obsolete>
909 Using -Qnew is questionable; it turns on new division by default, but
910 only in the __main__ module. You can usefully combine -Qwarn or
911 -Qwarnall and -Qnew: this gives the __main__ module new division, and
912 warns about classic division everywhere else.
913 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000914
Tim Petersbdee63f2001-09-02 03:40:59 +0000915- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000916 long, float, str, unicode, and tuple. (The types complex, list and
917 dictionary can also be subclassed; this was introduced earlier.)
918 Note that restrictions apply when subclassing immutable built-in
919 types: you can only affect the value of the instance by overloading
920 __new__. You can add mutable attributes, and the subclass instances
921 will have a __dict__ attribute, but you cannot change the "value"
922 (as implemented by the base class) of an immutable subclass instance
923 once it is created.
924
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000925- The dictionary constructor now takes an optional argument, a
926 mapping-like object, and initializes the dictionary from its
927 (key, value) pairs.
928
Tim Petersbdee63f2001-09-02 03:40:59 +0000929- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000930 "cooperative super calls" in a multiple inheritance setting. For an
931 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
932
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000933- A new built-in type, property, has been added. This enables the
934 creation of "properties". These are attributes implemented by
935 getter and setter functions (or only one of these for read-only or
936 write-only attributes), without the need to override __getattr__.
937 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000938
Tim Petersbdee63f2001-09-02 03:40:59 +0000939- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000940 liberalized, to allow leading zeroes. Examples of literals now
941 legal that were SyntaxErrors before:
942
943 00.0 0e3 0100j 07.5 00000000000000000008.
944
Tim Petersbdee63f2001-09-02 03:40:59 +0000945- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000946 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
947
Tim Petersedc99312001-08-22 21:36:50 +0000948Library
949
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000950- telnetlib includes symbolic names for the options, and support for
951 setting an option negotiation callback.
952
Tim Petersa40c7932001-09-05 22:36:56 +0000953- The new C standard no longer requires that math libraries set errno to
954 ERANGE on overflow. For platform libraries that exploit this new
955 freedom, Python's overflow-checking was wholly broken. A new overflow-
956 checking scheme attempts to repair that, but may not be reliable on all
957 platforms (C doesn't seem to provide anything both useful and portable
958 in this area anymore).
959
Martin v. Löwis44f86962001-09-05 13:44:54 +0000960- Asynchronous timeout actions are available through the new class
961 threading.Timer.
962
Tim Peters78526162001-09-05 00:53:45 +0000963- math.log and math.log10 now return sensible results for even huge
964 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
965
Tim Petersbdee63f2001-09-02 03:40:59 +0000966- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000967 currently held. See the docs for the imp module.
968
Tim Petersbdee63f2001-09-02 03:40:59 +0000969- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000970 dumps containing ints written on platforms where Python ints are 8 bytes.
971 When read on a box where Python ints are 4 bytes, such values are
972 converted to Python longs.
973
Tim Petersbdee63f2001-09-02 03:40:59 +0000974- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000975 code objects is no longer allowed. This plugs a security hole.
976
Steve Purcell6091cd62001-09-06 16:05:17 +0000977- unittest.TestResult instances no longer store references to tracebacks
978 generated by test failures. This prevents unexpected dangling references
979 to objects that should be garbage collected between tests.
980
Tim Petersedc99312001-08-22 21:36:50 +0000981Tools
982
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000983- Tools/scripts/fixdiv.py has been added which can be used to fix
984 division operators as per PEP 238.
985
Tim Petersedc99312001-08-22 21:36:50 +0000986Build
987
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000988- If you are an adventurous person using Mac OS X you may want to look at
989 Mac/OSX. There is a Makefile there that will build Python as a real Mac
990 application, which can be used for experimenting with Carbon or Cocoa.
991 Discussion of this on pythonmac-sig, please.
992
Tim Peters7eea37e2001-09-04 22:08:56 +0000993C API
994
995- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000996
Tim Peters9fffa3e2001-09-04 05:14:19 +0000997- Note that PyLong_AsDouble can fail! This has always been true, but no
998 callers checked for it. It's more likely to fail now, because overflow
999 errors are properly detected now. The proper way to check:
1000
1001 double x = PyLong_AsDouble(some_long_object);
1002 if (x == -1.0 && PyErr_Occurred()) {
1003 /* The conversion failed. */
1004 }
1005
Tim Petersbdee63f2001-09-02 03:40:59 +00001006- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001007 compile but will not participate in GC. To upgrade an extension
1008 module:
1009
1010 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001011
Neil Schemenauer4042c692001-08-30 15:38:01 +00001012 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1013 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001014
Neil Schemenauer4042c692001-08-30 15:38:01 +00001015 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1016 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001017
Neil Schemenauer4042c692001-08-30 15:38:01 +00001018 - remove PyGC_HEAD_SIZE from object size calculations
1019
1020 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1021
Tim Petersbdee63f2001-09-02 03:40:59 +00001022- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001023 These can be used safely to construct string objects from a
1024 sprintf-style format string (similar to the format string supported
1025 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001026
Tim Petersedc99312001-08-22 21:36:50 +00001027New platforms
1028
Tim Petersb7da0902001-09-02 23:01:43 +00001029- Stephen Hansen contributed patches sufficient to get a clean compile
1030 under Borland C (Windows), but he reports problems running it and ran
1031 out of time to complete the port. Volunteers? Expect a MemoryError
1032 when importing the types module; this is probably shallow, and
1033 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001034
Tim Petersedc99312001-08-22 21:36:50 +00001035Tests
1036
1037Windows
1038
Tim Peters6e13a562001-09-06 00:32:15 +00001039- Large file support is now enabled on Win32 platforms as well as on
1040 Win64. This means that, for example, you can use f.tell() and f.seek()
1041 to manipulate files larger than 2 gigabytes (provided you have enough
1042 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001043 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1044 filesize limit, and large file support makes no difference there.
1045 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1046 NTFS has no practical limit on file size, and files of any size can be
1047 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001048
Tim Petersbdee63f2001-09-02 03:40:59 +00001049- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001050 points to command.com (patch from Brian Quinlan).
1051
Tim Petersedc99312001-08-22 21:36:50 +00001052
Tim Peters20f51a72001-07-21 02:31:40 +00001053What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001054Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001055===========================
1056
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001057Build
1058
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001059- Tim Peters developed a brand new Windows installer using Wise 8.1,
1060 generously donated to us by Wise Solutions.
1061
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001062- configure supports a new option --enable-unicode, with the values
1063 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1064 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001065
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001066- A new configure option --enable-framework builds a Mac OS X framework,
1067 which "make frameworkinstall" will install. This provides a starting
1068 point for more mac-like functionality, join pythonmac-sig@python.org
1069 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001070
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001071- The NeXT platform is no longer supported.
1072
1073- The `new' module is now statically linked.
1074
Tim Peters0afb6092001-08-15 06:06:44 +00001075Tools
1076
1077- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001078 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001079 the module docstring for details.
1080
Tim Peters20f51a72001-07-21 02:31:40 +00001081Tests
1082
Tim Peters5e824c32001-08-12 22:25:01 +00001083- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001084 platforms, allowing to give clearer test result output. regrtest
1085 also has optional --use/-u switch to run normally disabled tests
1086 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001087
Tim Peters20f51a72001-07-21 02:31:40 +00001088- Several new tests in the standard test suite, with special thanks to
1089 Nick Mathewson.
1090
1091Core
1092
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001093- The floor division operator // has been added as outlined in PEP
1094 238. The / operator still provides classic division (and will until
1095 Python 3.0) unless "from __future__ import division" is included, in
1096 which case the / operator will provide true division. The operator
1097 module provides truediv() and floordiv() functions. Augmented
1098 assignment variants are included, as are the equivalent overloadable
1099 methods and C API methods. See the PEP for a full discussion:
1100 <http://python.sf.net/peps/pep-0238.html>
1101
Tim Peters6cd6a822001-08-17 22:11:27 +00001102- Future statements are now effective in simulated interactive shells
1103 (like IDLE). This should "just work" by magic, but read Michael
1104 Hudson's "Future statements in simulated shells" PEP 264 for full
1105 details: <http://python.sf.net/peps/pep-0264.html>.
1106
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001107- The type/class unification (PEP 252-253) was integrated into the
1108 trunk and is not so tentative any more (the exact specification of
1109 some features is still tentative). A lot of work has done on fixing
1110 bugs and adding robustness and features (performance still has to
1111 come a long way).
1112
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001113- Warnings about a mismatch in the Python API during extension import
1114 now use the Python warning framework (which makes it possible to
1115 write filters for these warnings).
1116
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001117- A function's __dict__ (aka func_dict) will now always be a
1118 dictionary. It used to be possible to delete it or set it to None,
1119 but now both actions raise TypeErrors. It is still legal to set it
1120 to a dictionary object. Getting func.__dict__ before any attributes
1121 have been assigned now returns an empty dictionary instead of None.
1122
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001123- A new command line option, -E, was added which disables the use of
1124 all environment variables, or at least those that are specifically
1125 significant to Python. Usually those have a name starting with
1126 "PYTHON". This was used to fix a problem where the tests fail if
1127 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1128 older distribution.
1129
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001130Library
1131
Tim Peters5e824c32001-08-12 22:25:01 +00001132- New class Differ and new functions ndiff() and restore() in difflib.py.
1133 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001134 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001135
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001136- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1137 value using the minimal quoting required for the value; more
1138 reliable than using xml.sax.saxutils.escape() for attribute values.
1139
1140- Readline completion support for cmd.Cmd was added.
1141
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001142- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1143
1144- Added function threading.BoundedSemaphore()
1145
1146- Added Ka-Ping Yee's cgitb.py module.
1147
1148- The `new' module now exposes the CO_xxx flags.
1149
Martin v. Löwis560da622001-11-24 09:24:51 +00001150- The gc module offers the get_referents function.
1151
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001152New platforms
1153
1154C API
1155
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001156- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1157 which provide a cross-platform implementations for the
1158 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1159 the standard sprintf() and vsprintf() C lib APIs, these versions
1160 apply bounds checking on the used buffer which enhances protection
1161 against buffer overruns.
1162
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001163- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001164 and extensions using different Unicode widths is rendered next to
1165 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001166 will result in an ImportError. Unicode extensions writers must make
1167 sure to check the Unicode width compatibility in their extensions by
1168 using at least one of the mangled Unicode APIs in the extension.
1169
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001170- Two new flags METH_NOARGS and METH_O are available in method definition
1171 tables to simplify implementation of methods with no arguments and a
1172 single untyped argument. Calling such methods is more efficient than
1173 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1174 deprecated.
1175
Tim Petersc1731372001-08-04 08:12:36 +00001176Windows
1177
1178- "import module" now compiles module.pyw if it exists and nothing else
1179 relevant is found.
1180
Tim Peters20f51a72001-07-21 02:31:40 +00001181
Guido van Rossum55a78992001-07-17 17:22:32 +00001182What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001183Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001184===========================
1185
1186Core
Tim Petersa814db52001-05-14 07:05:58 +00001187
Tim Peters6d6c1a32001-08-02 04:15:00 +00001188- TENTATIVELY, a large amount of code implementing much of what's
1189 described in PEP 252 (Making Types Look More Like Classes) and PEP
1190 253 (Subtyping Built-in Types) was added. This will be released
1191 with Python 2.2a1. Documentation will be provided separately
1192 through http://www.python.org/2.2/. The purpose of releasing this
1193 with Python 2.2a1 is to test backwards compatibility. It is
1194 possible, though not likely, that a decision is made not to release
1195 this code as part of 2.2 final, if any serious backwards
1196 incompapatibilities are found during alpha testing that cannot be
1197 repaired.
1198
Guido van Rossum55a78992001-07-17 17:22:32 +00001199- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001200 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001201 more 'yield' statements. See PEP 255. Since this adds a new
1202 keyword to the language, this feature must be enabled by including a
1203 future statement: "from __future__ import generators" (see PEP 236).
1204 Generators will become a standard feature in a future release
1205 (probably 2.3). Without this future statement, 'yield' remains an
1206 ordinary identifier, but a warning is issued each time it is used.
1207 (These warnings currently don't conform to the warnings framework of
1208 PEP 230; we intend to fix this in 2.2a2.)
1209
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001210- The UTF-16 codec was modified to be more RFC compliant. It will now
1211 only remove BOM characters at the start of the string and then
1212 only if running in native mode (UTF-16-LE and -BE won't remove a
1213 leading BMO character).
1214
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001215- Strings now have a new method .decode() to complement the already
1216 existing .encode() method. These two methods provide direct access
1217 to the corresponding decoders and encoders of the registered codecs.
1218
1219 To enhance the usability of the .encode() method, the special
1220 casing of Unicode object return values was dropped (Unicode objects
1221 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001222
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001223 Both methods will now return whatever the codec in charge of the
1224 requested encoding returns as object, e.g. Unicode codecs will
1225 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1226 will return u"äöü"). This enables codec writer to create codecs
1227 for various simple to use conversions.
1228
1229 New codecs were added to demonstrate these new features (the .encode()
1230 and .decode() columns indicate the type of the returned objects):
1231
1232 Name | .encode() | .decode() | Description
1233 ----------------------------------------------------------------------
1234 uu | string | string | UU codec (e.g. for email)
1235 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001236 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001237 zlib | string | string | zlib compression
1238 hex | string | string | 2-byte hex codec
1239 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1240
Mark Hammond2a0af792001-05-14 03:09:36 +00001241- Some operating systems now support the concept of a default Unicode
1242 encoding for file system operations. Notably, Windows supports 'mbcs'
1243 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001244 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001245 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001246
1247 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001248 functions that return filenames (such as os.listdir()) to return Python
1249 string objects pre-encoded using the default file system encoding for
1250 the platform. As this encoding is likely to be different from Python's
1251 default encoding, converting this name to a Unicode object before passing
1252 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001253 would attempt to use its default encoding (generally ASCII) rather than
1254 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001255
Tim Petersa814db52001-05-14 07:05:58 +00001256 In general, this change simply removes surprises when working with
1257 Unicode and the file system, making these operations work as you expect,
1258 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001259 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001260
Tim Peters61dff2b2001-05-08 15:43:37 +00001261- Float (and complex) literals in source code were evaluated to full
1262 precision only when running from a .py file; the same code loaded from a
1263 .pyc (or .pyo) file could suffer numeric differences starting at about the
1264 12th significant decimal digit. For example, on a machine with IEEE-754
1265 floating arithmetic,
1266
1267 x = 9007199254740992.0
1268 print long(x)
1269
1270 printed 9007199254740992 if run directly from .py, but 9007199254740000
1271 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1272 str(float) instead of repr(float) when building code objects. marshal
1273 now uses repr(float) instead, which should reproduce floats to full
1274 machine precision (assuming the platform C float<->string I/O conversion
1275 functions are of good quality).
1276
1277 This may cause floating-point results to change in some cases, and
1278 usually for the better, but may also cause numerically unstable
1279 algorithms to break.
1280
Tim Peters2f228e72001-05-13 00:19:31 +00001281- The implementation of dicts suffers fewer collisions, which has speed
1282 benefits. However, the order in which dict entries appear in dict.keys(),
1283 dict.values() and dict.items() may differ from previous releases for a
1284 given dict. Nothing is defined about this order, so no program should
1285 rely on it. Nevertheless, it's easy to write test cases that rely on the
1286 order by accident, typically because of printing the str() or repr() of a
1287 dict to an "expected results" file. See Lib/test/test_support.py's new
1288 sortdict(dict) function for a simple way to display a dict in sorted
1289 order.
1290
Tim Peters7a3bfc32001-06-12 01:22:22 +00001291- Many other small changes to dicts were made, resulting in faster
1292 operation along the most common code paths.
1293
Guido van Rossum10315822001-05-01 20:54:30 +00001294- Dictionary objects now support the "in" operator: "x in dict" means
1295 the same as dict.has_key(x).
1296
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001297- The update() method of dictionaries now accepts generic mapping
1298 objects. Specifically the argument object must support the .keys()
1299 and __getitem__() methods. This allows you to say, for example,
1300 {}.update(UserDict())
1301
Guido van Rossum10315822001-05-01 20:54:30 +00001302- Iterators were added; this is a generalized way of providing values
1303 to a for loop. See PEP 234. There's a new built-in function iter()
1304 to return an iterator. There's a new protocol to get the next value
1305 from an iterator using the next() method (in Python) or the
1306 tp_iternext slot (in C). There's a new protocol to get iterators
1307 using the __iter__() method (in Python) or the tp_iter slot (in C).
1308 Iterating (i.e. a for loop) over a dictionary generates its keys.
1309 Iterating over a file generates its lines.
1310
Tim Petersf553f892001-05-01 20:45:31 +00001311- The following functions were generalized to work nicely with iterator
1312 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001313 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001314 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1315 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001316 join() method of strings
1317 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001318 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1319 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001320 right-hand side of assignment statements with multiple targets, such as
1321 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001322
Tim Petersd85e1022001-05-11 21:51:48 +00001323- Accessing module attributes is significantly faster (for example,
1324 random.random or os.path or yourPythonModule.yourAttribute).
1325
Tim Peterse63415e2001-05-08 04:38:29 +00001326- Comparing dictionary objects via == and != is faster, and now works even
1327 if the keys and values don't support comparisons other than ==.
1328
Tim Peters95bf9392001-05-10 08:32:44 +00001329- Comparing dictionaries in ways other than == and != is slower: there were
1330 insecurities in the dict comparison implementation that could cause Python
1331 to crash if the element comparison routines for the dict keys and/or
1332 values mutated the dicts. Making the code bulletproof slowed it down.
1333
Tim Peterseb28ef22001-06-02 05:27:19 +00001334- Collisions in dicts are resolved via a new approach, which can help
1335 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001336 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001337 faster now. Thanks to Christian Tismer for pointing out the cause and
1338 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001339
Tim Peters52e155e2001-06-16 05:42:57 +00001340- repr() is much faster for large containers (dict, list, tuple).
1341
1342
Tim Petersa814db52001-05-14 07:05:58 +00001343Library
1344
Fred Drake960fdf92001-07-20 18:38:26 +00001345- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1346 were added to the string module. These a locale-indenpendent
1347 constants, unlike letters, lowercase, and uppercase. These are now
1348 use in appropriate locations in the standard library.
1349
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001350- The flags used in dlopen calls can now be configured using
1351 sys.setdlopenflags and queried using sys.getdlopenflags.
1352
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001353- Fredrik Lundh's xmlrpclib is now a standard library module. This
1354 provides full client-side XML-RPC support. In addition,
1355 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1356 one asyncore-based). Thanks to Eric Raymond for the documentation.
1357
Guido van Rossum643d3912001-07-05 14:46:25 +00001358- The xrange() object is simplified: it no longer supports slicing,
1359 repetition, comparisons, efficient 'in' checking, the tolist()
1360 method, or the start, stop and step attributes. See PEP 260.
1361
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001362- A new function fnmatch.filter to filter lists of file names was added.
1363
Barry Warsawffd674d2001-05-22 16:00:10 +00001364- calendar.py uses month and day names based on the current locale.
1365
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001366- strop is now *really* obsolete (this was announced before with 1.6),
1367 and issues DeprecationWarning when used (except for the four items
1368 that are still imported into string.py).
1369
Tim Petersa814db52001-05-14 07:05:58 +00001370- Cookie.py now sorts key+value pairs by key in output strings.
1371
1372- pprint.isrecursive(object) didn't correctly identify recursive objects.
1373 Now it does.
1374
Tim Peters95b3f782001-05-14 18:39:41 +00001375- pprint functions now much faster for large containers (tuple, list, dict).
1376
Tim Peters7b9542a2001-06-10 23:40:19 +00001377- New 'q' and 'Q' format codes in the struct module, corresponding to C
1378 types "long long" and "unsigned long long" (on Windows, __int64). In
1379 native mode, these can be used only when the platform C compiler supports
1380 these types (when HAVE_LONG_LONG is #define'd by the Python config
1381 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001382 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1383 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001384
Guido van Rossum83213cc2001-06-12 16:48:52 +00001385- The site module installs a new built-in function 'help' that invokes
1386 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1387 it displays a message reminding the user to use 'help()' or
1388 'help(object)'.
1389
Tim Petersa814db52001-05-14 07:05:58 +00001390Tests
1391
1392- New test_mutants.py runs dict comparisons where the key and value
1393 comparison operators mutute the dicts randomly during comparison. This
1394 rapidly causes Python to crash under earlier releases (not for the faint
1395 of heart: it can also cause Win9x to freeze or reboot!).
1396
1397- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001398 pprint.isreadable() return sensible results. Also verifies that simple
1399 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001400
Tim Peters4324aa32001-05-28 22:30:08 +00001401C API
1402
1403- Removed the unused last_is_sticky argument from the internal
1404 _PyTuple_Resize(). If this affects you, you were cheating.
1405
1406
Guido van Rossum55a78992001-07-17 17:22:32 +00001407======================================================================
1408
1409
Guido van Rossumffe13be2001-04-16 18:46:45 +00001410What's New in Python 2.1 (final)?
1411=================================
1412
1413We only changed a few things since the last release candidate, all in
1414Python library code:
1415
1416- A bug in the locale module was fixed that affected locales which
1417 define no grouping for numeric formatting.
1418
1419- A few bugs in the weakref module's implementations of weak
1420 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1421 and the test suite was updated to check for these bugs.
1422
1423- An old bug in the os.path.walk() function (introduced in Python
1424 2.0!) was fixed: a non-existent file would cause an exception
1425 instead of being ignored.
1426
1427- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1428 PyChecker.
1429
1430
Guido van Rossum5b08f132001-04-16 02:05:23 +00001431What's New in Python 2.1c2?
1432===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001433
Guido van Rossum5b08f132001-04-16 02:05:23 +00001434A flurry of small changes, and one showstopper fixed in the nick of
1435time made it necessary to release another release candidate. The list
1436here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001437
Guido van Rossum5b08f132001-04-16 02:05:23 +00001438Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001439
Guido van Rossum5b08f132001-04-16 02:05:23 +00001440- Tim discovered a nasty bug in the dictionary code, caused by
1441 PyDict_Next() calling dict_resize(), and the GC code's use of
1442 PyDict_Next() violating an assumption in dict_items(). This was
1443 fixed with considerable amounts of band-aid, but the net effect is a
1444 saner and more robust implementation.
1445
1446- Made a bunch of symbols static that were accidentally global.
1447
1448Build and Ports
1449
1450- The setup.py script didn't check for a new enough version of zlib
1451 (1.1.3 is needed). Now it does.
1452
1453- Changed "make clean" target to also remove shared libraries.
1454
1455- Added a more general warning about the SGI Irix optimizer to README.
1456
1457Library
1458
1459- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1460 omitted the slash between host and file.html.
1461
1462- The mailbox module's _Mailbox class contained a completely broken
1463 and undocumented seek() method. Ripped it out.
1464
1465- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1466 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1467
1468- Fixed a few last-minute bugs in unittest.
1469
1470Extensions
1471
1472- Reverted the patch to the OpenSSL code in socketmodule.c to support
1473 RAND_status() and the EGD, and the subsequent patch that tried to
1474 fix it for pre-0.9.5 versions; the problem with the patch is that on
1475 some systems it issues a warning whenever socket is imported, and
1476 that's unacceptable.
1477
1478Tests
1479
1480- Fixed the pickle tests to work with "import test.test_pickle".
1481
1482- Tweaked test_locale.py to actually run the test Windows.
1483
1484- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1485 not "wb" (which is not a valid mode at all).
1486
1487- Fix pstats browser crashes. Import readline if it exists to make
1488 the user interface nicer.
1489
1490- Add "import thread" to the top of test modules that import the
1491 threading module (test_asynchat and test_threadedtempfile). This
1492 prevents test failures caused by a broken threading module resulting
1493 from a previously caught failed import.
1494
1495- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1496 needed on some platforms (e.g. Solaris 8) when the tests are run
1497 twice in succession.
1498
1499- Skip rather than fail test_sunaudiodev if no audio device is found.
1500
1501
1502What's New in Python 2.1c1?
1503===========================
1504
1505This list was significantly updated when 2.1c2 was released; the 2.1c1
1506release didn't mention most changes that were actually part of 2.1c1:
1507
1508Legal
1509
1510- Copyright was assigned to the Python Software Foundation (PSF) and a
1511 PSF license (very similar to the CNRI license) was added.
1512
1513- The CNRI copyright notice was updated to include 2001.
1514
1515Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001516
Guido van Rossumc9932722001-04-12 02:31:27 +00001517- After a public outcry, assignment to __debug__ is no longer illegal;
1518 instead, a warning is issued. It will become illegal in 2.2.
1519
Guido van Rossum5b08f132001-04-16 02:05:23 +00001520- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1521 "%#x" now always prepends "0x", even if the value is zero.
1522
1523- Fixed some nits in the bytecode compiler.
1524
1525- Fixed core dumps when calling certain kinds of non-functions.
1526
1527- Fixed various core dumps caused by reference count bugs.
1528
1529Build and Ports
1530
1531- Use INSTALL_SCRIPT to install script files.
1532
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001533- New port: SCO Unixware 7, by Billy G. Allie.
1534
Guido van Rossum5b08f132001-04-16 02:05:23 +00001535- Updated RISCOS port.
1536
1537- Updated BeOS port and notes.
1538
1539- Various other porting problems resolved.
1540
1541Library
1542
1543- The TERMIOS and SOCKET modules are now truly obsolete and
1544 unnecessary. Their symbols are incorporated in the termios and
1545 socket modules.
1546
1547- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1548 better tests for pickling.
1549
1550- threading: make Condition.wait() robust against KeyboardInterrupt.
1551
1552- zipfile: add support to zipfile to support opening an archive
1553 represented by an open file rather than a file name. Fix bug where
1554 the archive was not properly closed. Fixed a bug in this bugfix
1555 where flush() was called for a read-only file.
1556
1557- imputil: added an uninstall() method to the ImportManager.
1558
1559- Canvas: fixed bugs in lower() and tkraise() methods.
1560
1561- SocketServer: API change (added overridable close_request() method)
1562 so that the TCP server can explicitly close the request.
1563
1564- pstats: Eric Raymond added a simple interactive statistics browser,
1565 invoked when the module is run as a script.
1566
1567- locale: fixed a problem in format().
1568
1569- webbrowser: made it work when the BROWSER environment variable has a
1570 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1571 KDE 2. Fixed some other nits.
1572
1573- unittest: changes to allow using a different exception than
1574 AssertionError, and added a few more function aliases. Some other
1575 small changes.
1576
1577- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1578
1579- asynchat: fixed a critical bug in asynchat that slipped through the
1580 2.1b2 release. Fixed another rare bug.
1581
1582- Fix some unqualified except: clauses (always a bad code example).
1583
1584XML
1585
1586- pyexpat: new API get_version_string().
1587
1588- Fixed some minidom bugs.
1589
1590Extensions
1591
1592- Fixed a core dump in _weakref. Removed the weakref.mapping()
1593 function (it adds nothing to the API).
1594
1595- Rationalized the use of header files in the readline module, to make
1596 it compile (albeit with some warnings) with the very recent readline
1597 4.2, without breaking for earlier versions.
1598
1599- Hopefully fixed a buffering problem in linuxaudiodev.
1600
1601- Attempted a fix to make the OpenSSL support in the socket module
1602 work again with pre-0.9.5 versions of OpenSSL.
1603
1604Tests
1605
1606- Added a test case for asynchat and asyncore.
1607
1608- Removed coupling between tests where one test failing could break
1609 another.
1610
1611Tools
1612
1613- Ping added an interactive help browser to pydoc, fixed some nits
1614 in the rest of the pydoc code, and added some features to his
1615 inspect module.
1616
1617- An updated python-mode.el version 4.1 which integrates Ken
1618 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1619 much nicer in XEmacs and Emacs. When stepping through your program
1620 with pdb, in either the shell window or the *Python* window, the
1621 source file and line will be tracked by an arrow. Very cool!
1622
1623- IDLE: syntax warnings in interactive mode are changed into errors.
1624
1625- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001626 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001627
1628- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001629
Barry Warsaw11e89c72001-04-11 20:37:57 +00001630
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001631What's New in Python 2.1 beta 2?
1632================================
1633
Guido van Rossum053ae352001-03-22 14:17:21 +00001634(Unlisted are many fixed bugs, more documentation, etc.)
1635
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001636Core language, builtins, and interpreter
1637
Guido van Rossum053ae352001-03-22 14:17:21 +00001638- The nested scopes work (enabled by "from __future__ import
1639 nested_scopes") is completed; in particular, the future now extends
1640 into code executed through exec, eval() and execfile(), and into the
1641 interactive interpreter.
1642
1643- When calling a base class method (e.g. BaseClass.__init__(self)),
1644 this is now allowed even if self is not strictly spoken a class
1645 instance (e.g. when using metaclasses or the Don Beaudry hook).
1646
1647- Slice objects are now comparable but not hashable; this prevents
1648 dict[:] from being accepted but meaningless.
1649
1650- Complex division is now calculated using less braindead algorithms.
1651 This doesn't change semantics except it's more likely to give useful
1652 results in extreme cases. Complex repr() now uses full precision
1653 like float repr().
1654
1655- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1656
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001657- It is illegal to assign to the name __debug__, which is set when the
1658 interpreter starts. It is effectively a compile-time constant.
1659
1660- A warning will be issued if a global statement for a variable
1661 follows a use or assignment of that variable.
1662
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001663Standard library
1664
Guido van Rossum053ae352001-03-22 14:17:21 +00001665- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1666 inspired by JUnit), is now part of the standard library. You now
1667 have a choice of two testing frameworks: unittest requires you to
1668 write testcases as separate code, doctest gathers them from
1669 docstrings. Both approaches have their advantages and
1670 disadvantages.
1671
1672- A new module Tix was added, which wraps the Tix extension library
1673 for Tk. With that module, it is not necessary to statically link
1674 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1675 require" command. See Demo/tix/.
1676
1677- tzparse.py is now obsolete.
1678
1679- In gzip.py, the seek() and tell() methods are removed -- they were
1680 non-functional anyway, and it's better if callers can test for their
1681 existence with hasattr().
1682
1683Python/C API
1684
1685- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1686 that's already in the dictionary during a PyDict_Next() iteration.
1687 This used to fail occasionally when a dictionary resize operation
1688 could be triggered that would rehash all the keys. All other
1689 modifications to the dictionary are still off-limits during a
1690 PyDict_Next() iteration!
1691
1692- New extended APIs related to passing compiler variables around.
1693
1694- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1695 implement isinstance() and issubclass().
1696
1697- Py_BuildValue() now has a "D" conversion to create a Python complex
1698 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001699
Fred Drake4e262a92001-03-22 18:26:47 +00001700- Extensions types which support weak references must now set the
1701 field allocated for the weak reference machinery to NULL themselves;
1702 this is done to avoid the cost of checking each object for having a
1703 weakly referencable type in PyObject_INIT(), since most types are
1704 not weakly referencable.
1705
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001706- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1707 free variables and cell variables to and from the frame's f_locals.
1708
1709- Variants of several functions defined in pythonrun.h have been added
1710 to support the nested_scopes future statement. The variants all end
1711 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1712 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1713 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001714 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001715
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001716Distutils
1717
1718- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1719 into the release tree.
1720
Tim Peters0e57abf2001-05-02 07:39:38 +00001721- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001722 (an uninstaller, more customization of the installer's display)
1723
1724- from Jack Jansen: added Mac-specific code to generate a dialog for
1725 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001726 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001727 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001728
1729- added 'platforms' and 'keywords' to the set of metadata that can be
1730 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001731
1732- applied patches from Jason Tishler to make the compiler class work with
1733 Cygwin.
1734
1735
Tim Peters2fe289a2001-03-01 22:19:38 +00001736What's New in Python 2.1 beta 1?
1737================================
Tim Petersd66595f2001-02-04 03:09:53 +00001738
1739Core language, builtins, and interpreter
1740
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001741- Following an outcry from the community about the amount of code
1742 broken by the nested scopes feature introduced in 2.1a2, we decided
1743 to make this feature optional, and to wait until Python 2.2 (or at
1744 least 6 months) to make it standard. The option can be enabled on a
1745 per-module basis by adding "from __future__ import nested_scopes" at
1746 the beginning of a module (before any other statements, but after
1747 comments and an optional docstring). See PEP 236 (Back to the
1748 __future__) for a description of the __future__ statement. PEP 227
1749 (Statically Nested Scopes) has been updated to reflect this change,
1750 and to clarify the semantics in a number of endcases.
1751
1752- The nested scopes code, when enabled, has been hardened, and most
1753 bugs and memory leaks in it have been fixed.
1754
1755- Compile-time warnings are now generated for a number of conditions
1756 that will break or change in meaning when nested scopes are enabled:
1757
1758 - Using "from...import *" or "exec" without in-clause in a function
1759 scope that also defines a lambda or nested function with one or
1760 more free (non-local) variables. The presence of the import* or
1761 bare exec makes it impossible for the compiler to determine the
1762 exact set of local variables in the outer scope, which makes it
1763 impossible to determine the bindings for free variables in the
1764 inner scope. To avoid the warning about import *, change it into
1765 an import of explicitly name object, or move the import* statement
1766 to the global scope; to avoid the warning about bare exec, use
1767 exec...in... (a good idea anyway -- there's a possibility that
1768 bare exec will be deprecated in the future).
1769
1770 - Use of a global variable in a nested scope with the same name as a
1771 local variable in a surrounding scope. This will change in
1772 meaning with nested scopes: the name in the inner scope will
1773 reference the variable in the outer scope rather than the global
1774 of the same name. To avoid the warning, either rename the outer
1775 variable, or use a global statement in the inner function.
1776
Neil Schemenauera35c6882001-02-27 04:45:05 +00001777- An optional object allocator has been included. This allocator is
1778 optimized for Python objects and should be faster and use less memory
1779 than the standard system allocator. It is not enabled by default
1780 because of possible thread safety problems. The allocator is only
1781 protected by the Python interpreter lock and it is possible that some
1782 extension modules require a thread safe allocator. The object
1783 allocator can be enabled by providing the "--with-pymalloc" option to
1784 configure.
1785
Tim Petersd66595f2001-02-04 03:09:53 +00001786Standard library
1787
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001788- pyexpat now detects the expat version if expat.h defines it. A
1789 number of additional handlers are provided, which are only available
1790 since expat 1.95. In addition, the methods SetParamEntityParsing and
1791 GetInputContext of Parser objects are available with 1.95.x
1792 only. Parser objects now provide the ordered_attributes and
1793 specified_attributes attributes. A new module expat.model was added,
1794 which offers a number of additional constants if 1.95.x is used.
1795
1796- xml.dom offers the new functions registerDOMImplementation and
1797 getDOMImplementation.
1798
1799- xml.dom.minidom offers a toprettyxml method. A number of DOM
1800 conformance issues have been resolved. In particular, Element now
1801 has an hasAttributes method, and the handling of namespaces was
1802 improved.
1803
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001804- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1805 getting information about live Python code, and pydoc.py, a module
1806 for interactively converting docstrings to HTML or text.
1807 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001808 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001809 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1810 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001811
Tim Peters1eff7962001-03-01 02:31:33 +00001812- New library module difflib.py, primarily packaging the SequenceMatcher
1813 class at the heart of the popular ndiff.py file-comparison tool.
1814
1815- doctest.py (a framework for verifying Python code examples in docstrings)
1816 is now part of the std library.
1817
Tim Petersd66595f2001-02-04 03:09:53 +00001818Windows changes
1819
Guido van Rossume3955a82001-03-02 14:05:59 +00001820- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1821 small GUI that lets you browse the module docstrings using your
1822 default web browser.
1823
Tim Peters1eff7962001-03-01 02:31:33 +00001824- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1825 Platforms) is implemented. See
1826
1827 http://python.sourceforge.net/peps/pep-0235.html
1828
1829 for full details, especially the "Current Lower-Left Semantics" section.
1830 The new Windows import rules are simpler than before:
1831
1832 A. If the PYTHONCASEOK environment variable exists, same as
1833 before: silently accept the first case-insensitive match of any
1834 kind; raise ImportError if none found.
1835
1836 B. Else search sys.path for the first case-sensitive match; raise
1837 ImportError if none found.
1838
1839 The same rules have been implented on other platforms with case-
1840 insensitive but case-preserving filesystems too (including Cygwin, and
1841 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001842
Tim Peters25a9ce32001-02-19 07:06:36 +00001843- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1844 what it's supposed to do (and does do under NT and 2000) via direct
1845 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001846 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001847 all Win9x systems before.
1848
Tim Peters1eff7962001-03-01 02:31:33 +00001849- Build: Subproject _test (effectively) renamed to _testcapi.
1850
Tim Peters2fe289a2001-03-01 22:19:38 +00001851New platforms
1852
1853- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1854 Thanks to Steven Majewski!
1855
1856- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1857 Tishler!
1858
Guido van Rossum9089b272001-03-02 06:49:50 +00001859- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1860 Schwertberger! See RISCOS/README for more information -- it seems
1861 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001862 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001863
Tim Peters25a9ce32001-02-19 07:06:36 +00001864
Tim Petersd7b5e882001-01-25 03:36:26 +00001865What's New in Python 2.1 alpha 2?
1866=================================
Tim Peters40ead762001-01-27 05:35:26 +00001867
Tim Petersd7b5e882001-01-25 03:36:26 +00001868Core language, builtins, and interpreter
1869
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001870- Scopes nest. If a name is used in a function or class, but is not
1871 local, the definition in the nearest enclosing function scope will
1872 be used. One consequence of this change is that lambda statements
1873 could reference variables in the namespaces where the lambda is
1874 defined. In some unusual cases, this change will break code.
1875
1876 In all previous version of Python, names were resolved in exactly
1877 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001878 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001879 function A is defined within a function B, the names bound in B are
1880 not visible in A. The new rules make names bound in B visible in A,
1881 unless A contains a name binding that hides the binding in B.
1882
1883 Section 4.1 of the reference manual describes the new scoping rules
1884 in detail. The test script in Lib/test/test_scope.py demonstrates
1885 some of the effects of the change.
1886
1887 The new rules will cause existing code to break if it defines nested
1888 functions where an outer function has local variables with the same
1889 name as globals or builtins used by the inner function. Example:
1890
1891 def munge(str):
1892 def helper(x):
1893 return str(x)
1894 if type(str) != type(''):
1895 str = helper(str)
1896 return str.strip()
1897
1898 Under the old rules, the name str in helper() is bound to the
1899 builtin function str(). Under the new rules, it will be bound to
1900 the argument named str and an error will occur when helper() is
1901 called.
1902
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001903- The compiler will report a SyntaxError if "from ... import *" occurs
1904 in a function or class scope. The language reference has documented
1905 that this case is illegal, but the compiler never checked for it.
1906 The recent introduction of nested scope makes the meaning of this
1907 form of name binding ambiguous. In a future release, the compiler
1908 may allow this form when there is no possibility of ambiguity.
1909
Tim Peters40ead762001-01-27 05:35:26 +00001910- repr(string) is easier to read, now using hex escapes instead of octal,
1911 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1912
1913 >>> "\texample \r\n" + chr(0) + chr(255)
1914 '\texample \r\n\x00\xff' # in 2.1
1915 '\011example \015\012\000\377' # in 2.0
1916
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001917- Functions are now compared and hashed by identity, not by value, since
1918 the func_code attribute is writable.
1919
Fred Drakefb9d7122001-02-01 20:00:40 +00001920- Weak references (PEP 205) have been added. This involves a few
1921 changes in the core, an extension module (_weakref), and a Python
1922 module (weakref). The weakref module is the public interface. It
1923 includes support for "explicit" weak references, proxy objects, and
1924 mappings with weakly held values.
1925
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001926- A 'continue' statement can now appear in a try block within the body
1927 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001928 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001929
Tim Petersd7b5e882001-01-25 03:36:26 +00001930Standard library
1931
Barry Warsaw30dbd142001-01-31 22:14:01 +00001932- mailbox.py now has a new class, PortableUnixMailbox which is
1933 identical to UnixMailbox but uses a more portable scheme for
1934 determining From_ separators. Also, the constructors for all the
1935 classes in this module have a new optional `factory' argument, which
1936 is a callable used when new message classes must be instantiated by
1937 the next() method.
1938
Tim Petersd7b5e882001-01-25 03:36:26 +00001939- random.py is now self-contained, and offers all the functionality of
1940 the now-deprecated whrandom.py. See the docs for details. random.py
1941 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001942 and restoring the internal state of the generator; and jumpahead(n),
1943 for quickly forcing the internal state to be the same as if n calls to
1944 random() had been made. The latter is particularly useful for multi-
1945 threaded programs, creating one instance of the random.Random() class for
1946 each thread, then using .jumpahead() to force each instance to use a
1947 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001948
Tim Peters0de88fc2001-02-01 04:59:18 +00001949- random.py's seed() function is new. For bit-for-bit compatibility with
1950 prior releases, use the whseed function instead. The new seed function
1951 addresses two problems: (1) The old function couldn't produce more than
1952 about 2**24 distinct internal states; the new one about 2**45 (the best
1953 that can be done in the Wichmann-Hill generator). (2) The old function
1954 sometimes produced identical internal states when passed distinct
1955 integers, and there was no simple way to predict when that would happen;
1956 the new one guarantees to produce distinct internal states for all
1957 arguments in [0, 27814431486576L).
1958
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001959- The socket module now supports raw packets on Linux. The socket
1960 family is AF_PACKET.
1961
Tim Peters9ea17ac2001-02-02 05:57:15 +00001962- test_capi.py is a start at running tests of the Python C API. The tests
1963 are implemented by the new Modules/_testmodule.c.
1964
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001965- A new extension module, _symtable, provides provisional access to the
1966 internal symbol table used by the Python compiler. A higher-level
1967 interface will be added on top of _symtable in a future release.
1968
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001969- Removed the obsolete soundex module.
1970
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001971- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1972 the isSameNode method; NamedNodeMap the get method.
1973
1974- xml.sax.expatreader supports the lexical handler property; it
1975 generates comment, startCDATA, and endCDATA events.
1976
Tim Petersee826f82001-01-31 19:39:44 +00001977Windows changes
1978
1979- Build procedure: the zlib project is built in a different way that
1980 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001981 the zlib binary used. See PCbuild\readme.txt for details. Your old
1982 zlib-related directories can be deleted; you'll need to download fresh
1983 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001984
Tim Peters9ea17ac2001-02-02 05:57:15 +00001985- Build: New subproject _test for the benefit of test_capi.py (see above).
1986
Tim Petersb16c56f2001-02-02 21:24:51 +00001987- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1988 interface to some Python compiler internals).
1989
1990- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001991 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001992
Tim Petersa3a3a032000-11-30 05:22:44 +00001993What's New in Python 2.1 alpha 1?
1994=================================
1995
1996Core language, builtins, and interpreter
1997
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001998- There is a new Unicode companion to the PyObject_Str() API
1999 called PyObject_Unicode(). It behaves in the same way as the
2000 former, but assures that the returned value is an Unicode object
2001 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002002
Guido van Rossumf98eda02001-01-17 15:54:45 +00002003- The comparison operators support "rich comparison overloading" (PEP
2004 207). C extension types can provide a rich comparison function in
2005 the new tp_richcompare slot in the type object. The cmp() function
2006 and the C function PyObject_Compare() first try the new rich
2007 comparison operators before trying the old 3-way comparison. There
2008 is also a new C API PyObject_RichCompare() (which also falls back on
2009 the old 3-way comparison, but does not constrain the outcome of the
2010 rich comparison to a Boolean result).
2011
2012 The rich comparison function takes two objects (at least one of
2013 which is guaranteed to have the type that provided the function) and
2014 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2015 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2016 object, which may be NotImplemented (in which case the tp_compare
2017 slot function is used as a fallback, if defined).
2018
2019 Classes can overload individual comparison operators by defining one
2020 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002021 __ge__. There are no explicit "reflected argument" versions of
2022 these; instead, __lt__ and __gt__ are each other's reflection,
2023 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2024 reflection (similar at the C level). No other implications are
2025 made; in particular, Python does not assume that == is the Boolean
2026 inverse of !=, or that < is the Boolean inverse of >=. This makes
2027 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002028
2029 Classes or types that want to implement (in)equality tests but not
2030 the ordering operators (i.e. unordered types) should implement ==
2031 and !=, and raise an error for the ordering operators.
2032
Guido van Rossuma88479f2001-01-18 14:28:08 +00002033 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002034 Boolean; e.g. a matrix type might want to return a matrix of bits
2035 for A < B, giving elementwise comparisons. Such types should ensure
2036 that any interpretation of their value in a Boolean context raises
2037 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2038 at the C level) to always raise an exception.
2039
Guido van Rossuma88479f2001-01-18 14:28:08 +00002040- Complex numbers use rich comparisons to define == and != but raise
2041 an exception for <, <=, > and >=. Unfortunately, this also means
2042 that cmp() of two complex numbers raises an exception when the two
2043 numbers differ. Since it is not mathematically meaningful to compare
2044 complex numbers except for equality, I hope that this doesn't break
2045 too much code.
2046
Tim Peters3389f192001-02-18 08:48:49 +00002047- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002048 not defined by the language, other than that it's arbitrary but
2049 consistent (see the Reference Manual). An implementation detail changed
2050 in 2.1a1 such that None now compares less than any other object. Code
2051 relying on this new behavior (like code that relied on the previous
2052 behavior) does so at its own risk.
2053
Barry Warsaw573b5412001-01-15 20:43:18 +00002054- Functions and methods now support getting and setting arbitrarily
2055 named attributes (PEP 232). Functions have a new __dict__
2056 (a.k.a. func_dict) which hold the function attributes. Methods get
2057 and set attributes on their underlying im_func. It is a TypeError
2058 to set an attribute on a bound method.
2059
Guido van Rossum051e3352001-01-15 19:11:10 +00002060- The xrange() object implementation has been improved so that
2061 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2062 limitation that in this case len(xrange(sys.maxint)) can't be
2063 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2064 work fine as long as the index i doesn't actually reach 2**31.
2065 (Python uses regular ints for sequence and string indices; fixing
2066 that is much more work.)
2067
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002068- Two changes to from...import:
2069
Guido van Rossumba381232001-02-03 15:06:40 +00002070 1) "from M import X" now works even if (after loading module M)
2071 sys.modules['M'] is not a real module; it's basically a getattr()
2072 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002073
2074 2) "from M import *" now looks for M.__all__ to decide which names to
2075 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2076 filters out names starting with '_' as before. Whether or not
2077 __all__ exists, there's no restriction on the type of M.
2078
Guido van Rossumf61f1662001-01-10 20:13:55 +00002079- File objects have a new method, xreadlines(). This is the fastest
2080 way to iterate over all lines in a file:
2081
2082 for line in file.xreadlines():
2083 ...do something to line...
2084
2085 See the xreadlines module (mentioned below) for how to do this for
2086 other file-like objects.
2087
2088- Even if you don't use file.xreadlines(), you may expect a speedup on
2089 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002090 quite a bit in platform-specific ways: on systems (like Linux) that
2091 support flockfile(), getc_unlocked(), and funlockfile(), those are
2092 used by default. On systems (like Windows) without getc_unlocked(),
2093 a complicated (but still thread-safe) method using fgets() is used by
2094 default.
2095
Tim Petersd52269b2001-01-25 06:23:18 +00002096 You can force use of the fgets() method by #define'ing
2097 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002098 getc_unlocked()).
2099
Tim Petersd52269b2001-01-25 06:23:18 +00002100 You can force fgets() not to be used by #define'ing
2101 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002102 test_bufio.py fails -- and let us know if it does!).
2103
2104- In addition, the fileinput module, while still slower than the other
2105 methods on most platforms, has been sped up too, by using
2106 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002107
2108- Support for run-time warnings has been added, including a new
2109 command line option (-W) to specify the disposition of warnings.
2110 See the description of the warnings module below.
2111
2112- Extensive changes have been made to the coercion code. This mostly
2113 affects extension modules (which can now implement mixed-type
2114 numerical operators without having to use coercion), but
2115 occasionally, in boundary cases the coercion semantics have changed
2116 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002117 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002118 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002119 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002120
Guido van Rossumf98eda02001-01-17 15:54:45 +00002121- In connection with the coercion changes, a new built-in singleton
2122 object, NotImplemented is defined. This can be returned for
2123 operations that wish to indicate they are not implemented for a
2124 particular combination of arguments. From C, this is
2125 Py_NotImplemented.
2126
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002127- The interpreter accepts now bytecode files on the command line even
2128 if they do not have a .pyc or .pyo extension. On Linux, after executing
2129
Martin v. Löwise214baa2001-02-04 22:37:56 +00002130import imp,sys,string
2131magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2132reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2133open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002134
2135 any byte code file can be used as an executable (i.e. as an argument
2136 to execve(2)).
2137
Tim Peters9940b802000-12-01 07:59:35 +00002138- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002139 character. In 1.6 and earlier, they never produced a sign,
2140 and raised an error if the value of the long was too large
2141 to fit in a Python int. In 2.0, they produced a sign if and
2142 only if too large to fit in an int. This was inconsistent
2143 across platforms (because the size of an int varies across
2144 platforms), and inconsistent with hex() and oct(). Example:
2145
2146 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002147 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002148 'ffffffbe' # in 2.0 and before, on 32-bit machines
2149 >>> hex(-0x42L)
2150 '-0x42L' # in all versions of Python
2151
Tim Peters9940b802000-12-01 07:59:35 +00002152 The behavior of %d formats for negative Python longs remains
2153 the same as in 2.0 (although in 1.6 and before, they raised
2154 an error if the long didn't fit in a Python int).
2155
2156 %u formats don't make sense for Python longs, but are allowed
2157 and treated the same as %d in 2.1. In 2.0, a negative long
2158 formatted via %u produced a sign if and only if too large to
2159 fit in an int. In 1.6 and earlier, a negative long formatted
2160 via %u raised an error if it was too big to fit in an int.
2161
Guido van Rossum3661d392000-12-12 22:10:31 +00002162- Dictionary objects have an odd new method, popitem(). This removes
2163 an arbitrary item from the dictionary and returns it (in the form of
2164 a (key, value) pair). This can be useful for algorithms that use a
2165 dictionary as a bag of "to do" items and repeatedly need to pick one
2166 item. Such algorithms normally end up running in quadratic time;
2167 using popitem() they can usually be made to run in linear time.
2168
Tim Peters36cdad12000-12-29 02:06:45 +00002169Standard library
2170
Thomas Woutersfe385252001-01-19 23:16:56 +00002171- In the time module, the time argument to the functions strftime,
2172 localtime, gmtime, asctime and ctime is now optional, defaulting to
2173 the current time (in the local timezone).
2174
Guido van Rossumda91f222001-01-15 16:36:08 +00002175- The ftplib module now defaults to passive mode, which is deemed a
2176 more useful default given that clients are often inside firewalls
2177 these days. Note that this could break if ftplib is used to connect
2178 to a *server* that is inside a firewall, from outside; this is
2179 expected to be a very rare situation. To fix that, you can call
2180 ftp.set_pasv(0).
2181
Martin v. Löwis10a27872001-01-13 09:54:41 +00002182- The module site now treats .pth files not only for path configuration,
2183 but also supports extensions to the initialization code: Lines starting
2184 with import are executed.
2185
Guido van Rossumf61f1662001-01-10 20:13:55 +00002186- There's a new module, warnings, which implements a mechanism for
2187 issuing and filtering warnings. There are some new built-in
2188 exceptions that serve as warning categories, and a new command line
2189 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2190 turns warnings into errors). warnings.warn(message[, category])
2191 issues a warning message; this can also be called from C as
2192 PyErr_Warn(category, message).
2193
2194- A new module xreadlines was added. This exports a single factory
2195 function, xreadlines(). The intention is that this code is the
2196 absolutely fastest way to iterate over all lines in an open
2197 file(-like) object:
2198
2199 import xreadlines
2200 for line in xreadlines.xreadlines(file):
2201 ...do something to line...
2202
2203 This is equivalent to the previous the speed record holder using
2204 file.readlines(sizehint). Note that if file is a real file object
2205 (as opposed to a file-like object), this is equivalent:
2206
2207 for line in file.xreadlines():
2208 ...do something to line...
2209
Tim Peters36cdad12000-12-29 02:06:45 +00002210- The bisect module has new functions bisect_left, insort_left,
2211 bisect_right and insort_right. The old names bisect and insort
2212 are now aliases for bisect_right and insort_right. XXX_right
2213 and XXX_left methods differ in what happens when the new element
2214 compares equal to one or more elements already in the list: the
2215 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002216 right. Code that doesn't care where equal elements end up should
2217 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002218
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002219- The new curses.panel module wraps the panel library that forms part
2220 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2221
Guido van Rossumf61f1662001-01-10 20:13:55 +00002222- The SocketServer module now sets the allow_reuse_address flag by
2223 default in the TCPServer class.
2224
2225- A new function, sys._getframe(), returns the stack frame pointer of
2226 the caller. This is intended only as a building block for
2227 higher-level mechanisms such as string interpolation.
2228
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002229- The pyexpat module supports a number of new handlers, which are
2230 available only in expat 1.2. If invocation of a callback fails, it
2231 will report an additional frame in the traceback. Parser objects
2232 participate now in garbage collection. If expat reports an unknown
2233 encoding, pyexpat will try to use a Python codec; that works only
2234 for single-byte charsets. The parser type objects is exposed as
2235 XMLParserObject.
2236
2237- xml.dom now offers standard definitions for symbolic node type and
2238 exception code constants, and a hierarchy of DOM exceptions. minidom
2239 was adjusted to use them.
2240
2241- The conformance of xml.dom.minidom to the DOM specification was
2242 improved. It detects a number of additional error cases; the
2243 previous/next relationship works even when the tree is modified;
2244 Node supports the normalize() method; NamedNodeMap, DocumentType and
2245 DOMImplementation classes were added; Element supports the
2246 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2247 method.
2248
Guido van Rossumf61f1662001-01-10 20:13:55 +00002249Build issues
2250
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002251- For Unix (and Unix-compatible) builds, configuration and building of
2252 extension modules is now greatly automated. Rather than having to
2253 edit the Modules/Setup file to indicate which modules should be
2254 built and where their include files and libraries are, a
2255 distutils-based setup.py script now takes care of building most
2256 extension modules. All extension modules built this way are built
2257 as shared libraries. Only a few modules that must be linked
2258 statically are still listed in the Setup file; you won't need to
2259 edit their configuration.
2260
2261- Python should now build out of the box on Cygwin. If it doesn't,
2262 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002263
2264- Python now always uses its own (renamed) implementation of getopt()
2265 -- there's too much variation among C library getopt()
2266 implementations.
2267
2268- C++ compilers are better supported; the CXX macro is always set to a
2269 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002270
Tim Petersd92dfe02000-12-12 01:18:41 +00002271Windows changes
2272
2273- select module: By default under Windows, a select() call
2274 can specify no more than 64 sockets. Python now boosts
2275 this Microsoft default to 512. If you need even more than
2276 that, see the MS docs (you'll need to #define FD_SETSIZE
2277 and recompile Python from source).
2278
Guido van Rossumf61f1662001-01-10 20:13:55 +00002279- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2280 subdirectory is no more!
2281
Tim Petersa3a3a032000-11-30 05:22:44 +00002282
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002283What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002284=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002285
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002286Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002287changes are in the file HISTORY. If you are making the jump directly
2288from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2289HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002290
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002291Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2292the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2293http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002294
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002295--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002296
2297======================================================================
2298
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002299What's new in 2.0 (since release candidate 1)?
2300==============================================
2301
2302Standard library
2303
2304- The copy_reg module was modified to clarify its intended use: to
2305 register pickle support for extension types, not for classes.
2306 pickle() will raise a TypeError if it is passed a class.
2307
2308- Fixed a bug in gettext's "normalize and expand" code that prevented
2309 it from finding an existing .mo file.
2310
2311- Restored support for HTTP/0.9 servers in httplib.
2312
Tim Peters989b7b92000-10-16 20:24:53 +00002313- The math module was changed to stop raising OverflowError in case of
2314 underflow, and return 0 instead in underflow cases. Whether Python
2315 used to raise OverflowError in case of underflow was platform-
2316 dependent (it did when the platform math library set errno to ERANGE
2317 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002318
2319- Fixed a bug in StringIO that occurred when the file position was not
2320 at the end of the file and write() was called with enough data to
2321 extend past the end of the file.
2322
2323- Fixed a bug that caused Tkinter error messages to get lost on
2324 Windows. The bug was fixed by replacing direct use of
2325 interp->result with Tcl_GetStringResult(interp).
2326
2327- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2328 redirect response.
2329
2330- Several changes were made to distutils: Some debugging code was
2331 removed from util. Fixed the installer used when an external zip
2332 program (like WinZip) is not found; the source code for this
2333 installer is in Misc/distutils. check_lib() was modified to behave
2334 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2335 test for whether installed modules are on sys.path was changed to
2336 use both normcase() and normpath().
2337
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002338- Several minor bugs were fixed in the xml package (the minidom,
2339 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002340
2341- The regression test driver (regrtest.py) behavior when invoked with
2342 -l changed: It now reports a count of objects that are recognized as
2343 garbage but not freed by the garbage collector.
2344
Tim Peters989b7b92000-10-16 20:24:53 +00002345- The regression test for the math module was changed to test
2346 exceptional behavior when the test is run in verbose mode. Python
2347 cannot yet guarantee consistent exception behavior across platforms,
2348 so the exception part of test_math is run only in verbose mode, and
2349 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002350
2351Internals
2352
2353- PyOS_CheckStack() has been disabled on Win64, where it caused
2354 test_sre to fail.
2355
2356Build issues
2357
2358- Changed compiler flags, so that gcc is always invoked with -Wall and
2359 -Wstrict-prototypes. Users compiling Python with GCC should see
2360 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002361 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002362 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002363
Tim Petersa3a3a032000-11-30 05:22:44 +00002364- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002365
2366Tools and other miscellany
2367
2368- The compiler in Tools/compiler was updated to support the new
2369 language features introduced in 2.0: extended print statement, list
2370 comprehensions, and augmented assignments. The new compiler should
2371 also be backwards compatible with Python 1.5.2; the compiler will
2372 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002373 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002374
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002375What's new in 2.0 release candidate 1 (since beta 2)?
2376=====================================================
2377
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002378What is release candidate 1?
2379
2380We believe that release candidate 1 will fix all known bugs that we
2381intend to fix for the 2.0 final release. This release should be a bit
2382more stable than the previous betas. We would like to see even more
2383widespread testing before the final release, so we are producing this
2384release candidate. The final release will be exactly the same unless
2385any show-stopping (or brown bag) bugs are found by testers of the
2386release candidate.
2387
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002388All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002389to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002390
2391Core language, builtins, and interpreter
2392
2393- A bug that caused crashes when __coerce__ was used with augmented
2394 assignment, e.g. +=, was fixed.
2395
2396- Raise ZeroDivisionError when raising zero to a negative number,
2397 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2398 power operator and the result of math.pow(0.0, -2.0) will vary by
2399 platform. On Linux, it raises a ValueError.
2400
2401- A bug in Unicode string interpolation was fixed that occasionally
2402 caused errors with formats including "%%". For example, the
2403 following expression "%% %s" % u"abc" no longer raises a TypeError.
2404
2405- Compilation of deeply nested expressions raises MemoryError instead
2406 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2407
2408- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2409 rendering them useless. They are now written in binary mode again.
2410
2411Standard library
2412
2413- Keyword arguments are now accepted for most pattern and match object
2414 methods in SRE, the standard regular expression engine.
2415
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002416- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002417 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002418
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002419- Several bugs in the Unicode handling and error handling in _tkinter
2420 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002421
2422- Fix memory management errors in Merge() and Tkapp_Call() routines.
2423
2424- Several changes were made to cStringIO to make it compatible with
2425 the file-like object interface and with StringIO. If operations are
2426 performed on a closed object, an exception is raised. The truncate
2427 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002428 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002429
2430- There were many changes made to the linuxaudiodev module and its
2431 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002432 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002433
2434 Note that this module is named poorly, because it should work
2435 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002436 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002437
2438 The module now raises exceptions when errors occur instead of
2439 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2440 audio) and defines a getptr() method that calls the
2441 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2442
2443- The library_version attribute, introduced in an earlier beta, was
2444 removed because it can not be supported with early versions of the C
2445 readline library, which provides no way to determine the version at
2446 compile-time.
2447
2448- The binascii module is now enabled on Win64.
2449
Tim Peters46446d62000-10-09 21:19:31 +00002450- tokenize.py no longer suffers "recursion depth" errors when parsing
2451 programs with very long string literals.
2452
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002453Internals
2454
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002455- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002456 which is called when the interpreter starts up to determine where
2457 the standard library is installed. These vulnerabilities affect all
2458 previous versions of Python and can be exploited by setting very
2459 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2460 setuid Python script, although use of the wrapper in
2461 Misc/setuid-prog.c will eliminate the vulnerability.
2462
2463- Fixed garbage collection bugs in instance creation that were
2464 triggered when errors occurred during initialization. The solution,
2465 applied in cPickle and in PyInstance_New(), is to call
2466 PyObject_GC_Init() after the initialization of the object's
2467 container attributes is complete.
2468
2469- pyexpat adds definitions of PyModule_AddStringConstant and
2470 PyModule_AddObject if the Python version is less than 2.0, which
2471 provides compatibility with PyXML on Python 1.5.2.
2472
2473- If the platform has a bogus definition for LONG_BIT (the number of
2474 bits in a long), an error will be reported at compile time.
2475
2476- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2477 collection crashes and possibly other, unreported crashes.
2478
2479- Fixed a memory leak in _PyUnicode_Fini().
2480
2481Build issues
2482
2483- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002484 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002485 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002486
2487- The mmap.PAGESIZE constant is now initialized using sysconf when
2488 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2489
2490- The md5 file should now compile on all platforms.
2491
2492- The select module now compiles on platforms that do not define
2493 POLLRDNORM and related constants.
2494
2495- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002496 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002497
Jeremy Hylton10921202000-10-09 18:34:12 +00002498- BeOS: A number of changes were made to the build and installation
2499 process. ar-fake now operates on a directory of object files.
2500 dl_export.h is gone, and its macros now appear on the mwcc command
2501 line during build on PPC BeOS.
2502
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002503- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002504 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002505
2506- Cygwin: Support for shared libraries, Tkinter, and sockets.
2507
2508- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2509
2510Tools and other miscellany
2511
2512- Removed debugging prints from main used with freeze.
2513
Tim Peters46446d62000-10-09 21:19:31 +00002514- IDLE auto-indent no longer crashes when it encounters Unicode
2515 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002516
2517What's new in 2.0 beta 2 (since beta 1)?
2518========================================
2519
2520Core language, builtins, and interpreter
2521
Tim Peters482c0212000-09-26 06:33:09 +00002522- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002523 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002524
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002525- Add -h and -V command line options to print the usage message and
2526 Python version number and exit immediately.
2527
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002528- eval() and exec accept Unicode objects as code parameters.
2529
2530- getattr() and setattr() now also accept Unicode objects for the
2531 attribute name, which are converted to strings using the default
2532 encoding before lookup.
2533
2534- Multiplication on string and Unicode now does proper bounds
2535 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2536 string is too long."
2537
2538- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002539 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002540
Jeremy Hylton1b618592000-09-26 05:32:36 +00002541
2542Standard library and extensions
2543
Guido van Rossum5b08f132001-04-16 02:05:23 +00002544- socket module: the OpenSSL code now adds support for RAND_status()
2545 and EGD (Entropy Gathering Device).
2546
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002547- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002548 argument checking; it still takes no arguments.
2549
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002550- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002551
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002552- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002553
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002554- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002555
2556- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002557 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002558
2559- copy: Copy Unicode objects atomically.
2560
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002561- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002562
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002563- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002564
Fred Drake67233bc2000-09-26 16:40:27 +00002565- dbm: Add get() and setdefault() methods to dbm object. Add constant
2566 `library' to module that names the library used. Added doc strings
2567 and method names to error messages. Uses configure to determine
2568 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2569 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002570
2571- distutils: Update to version 0.9.3.
2572
2573- dl: Add several dl.RTLD_ constants.
2574
2575- fpectl: Now supported on FreeBSD.
2576
2577- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2578 found by the collector will be saved in gc.garbage. This is useful
2579 for debugging a program that creates reference cycles.
2580
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002581- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002582 of HTTP class. Do not close socket on zero-length response. Do not
2583 crash when server sends invalid content-length header.
2584
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002585- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002586
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002587- marshal: When reading a short, sign-extend on platforms where shorts
2588 are bigger than 16 bits. When reading a long, repair the unportable
2589 sign extension that was being done for 64-bit machines. (It assumed
2590 that signed right shift sign-extends.)
2591
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002592- operator: Add contains(), invert(), __invert__() as aliases for
2593 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002594
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002595- os: Add support for popen2() and popen3() on all platforms where
2596 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002597
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002598- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002599 clicking on a file in Explorer (or passing the file name to the
2600 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002601
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002602- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002603 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002604
2605- pickle: Now raises ValueError when an invalid pickle that contains
2606 a non-string repr where a string repr was expected. This behavior
2607 matches cPickle.
2608
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002609- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002610
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002611- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002612
2613- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002614 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002615 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002616
2617- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002618 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002619
2620- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002621 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002622 few cycles during startup since the first call to
2623 setdefaultencoding() will initialize the codec registry and the
2624 encodings package.
2625
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002626- socket: Support for size hint in readlines() method of object returned
2627 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002628
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002629- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002630 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002631 is followed by whitespace.
2632
Tim Petersa3a3a032000-11-30 05:22:44 +00002633- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002634
2635- struct: Check ranges for bytes and shorts.
2636
2637- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002638 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002639
2640- Tkinter: Image objects are now guaranteed to have unique ids. Set
2641 event.delta to zero if Tk version doesn't support mousewheel.
2642 Removed some debugging prints.
2643
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002644- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002645
Fred Drake67233bc2000-09-26 16:40:27 +00002646- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002647 which works around a bug in Norton AntiVirus 2000 that leads directly
2648 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002649
2650- xml: New version detection code allows PyXML to override standard
2651 XML package if PyXML version is greater than 0.6.1.
2652
Fred Drake64bb3802000-09-26 16:21:35 +00002653- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2654 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2655 tree only for nodes which are sufficiently interesting to a specific
2656 application. Does not provide the HTML-specific extensions. Still
2657 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002658
Fred Drake64bb3802000-09-26 16:21:35 +00002659- xml.sax: SAX 2 support for Python, including all the handler
2660 interfaces needed to process XML 1.0 compliant XML. Some
2661 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002662
Fred Drake64bb3802000-09-26 16:21:35 +00002663- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2664 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002665
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002666
Jeremy Hylton1b618592000-09-26 05:32:36 +00002667C API
2668
2669- Add three new convenience functions for module initialization --
2670 PyModule_AddObject(), PyModule_AddIntConstant(), and
2671 PyModule_AddStringConstant().
2672
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002673- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002674 removed and add #error to Python.h if NULL isn't defined after
2675 #include of stdio.h.
2676
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002677- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002678 backwards compatibility (at the source level) with old extensions.
2679
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002680- A wrapper API was added for signal() and sigaction(). Instead of
2681 either function, always use PyOS_getsig() to get a signal handler
2682 and PyOS_setsig() to set one. A new convenience typedef
2683 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002686 internal data buffer and size of a string object -- or the default
2687 encoded version of a Unicode object.
2688
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002689- PyString_Size() and PyString_AsString() accept Unicode objects.
2690
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002691- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002692 exists). INT_MAX and LONG_MAX will always be defined, even if
2693 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002694
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002695- PyFloat_FromString takes a second argument, pend, that was
2696 effectively useless. It is now officially useless but preserved for
2697 backwards compatibility. If the pend argument is not NULL, *pend is
2698 set to NULL.
2699
2700- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2701 for the attribute name. See note on getattr() above.
2702
2703- A few bug fixes to argument processing for Unicode.
2704 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2705 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2706 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002707 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002708
2709- Py_BuildValue accepts B format (for bgen-generated code).
2710
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002711
Jeremy Hylton1b618592000-09-26 05:32:36 +00002712Internals
2713
2714- On Unix, fix code for finding Python installation directory so that
2715 it works when argv[0] is a relative path.
2716
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002717- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002718 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002719 rather than by generating a copy of the object.
2720
Tim Peters482c0212000-09-26 06:33:09 +00002721- Several of the internal Unicode tables are much smaller now, and
2722 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002723
Jeremy Hylton97693b02000-09-26 17:42:51 +00002724- In the garbage collector: Fixed bug in collection of tuples. Fixed
2725 bug that caused some instances to be removed from the container set
2726 while they were still live. Fixed parsing in gc.set_debug() for
2727 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002728
2729- Fixed refcount problem in instance deallocation that only occurred
2730 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2731
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002732- On Windows, getpythonregpath is now protected against null data in
2733 registry key.
2734
2735- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002736 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002737
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002738
Jeremy Hylton1b618592000-09-26 05:32:36 +00002739Build and platform-specific issues
2740
2741- Better support of GNU Pth via --with-pth configure option.
2742
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002743- Python/C API now properly exposed to dynamically-loaded extension
2744 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002745
2746- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2747 Don't define MS_SYNC to be zero when it is undefined. Added missing
2748 prototypes in posixmodule.c.
2749
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002750- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002751 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002753- Fix largefile support on older NetBSD systems and OpenBSD by adding
2754 define for TELL64.
2755
2756
2757Tools and other miscellany
2758
2759- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2760
2761- freeze: The modulefinder now works with 2.0 opcodes.
2762
Tim Petersa3a3a032000-11-30 05:22:44 +00002763- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002764 Move hackery of sys.argv until after the Tk instance has been
2765 created, which allows the application-specific Tkinter
2766 initialization to be executed if present; also pass an explicit
2767 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002768
Jeremy Hylton1b618592000-09-26 05:32:36 +00002769
2770What's new in 2.0 beta 1?
2771=========================
2772
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002773Source Incompatibilities
2774------------------------
2775
2776None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2777such as single-argument append(), connect() and bind(), and changes to
2778str(long) and repr(float).
2779
2780
2781Binary Incompatibilities
2782------------------------
2783
2784- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2785with Python 2.0; these extensions will have to be rebuilt for Python
27862.0.
2787
2788- On Windows, attempting to import a third party extension built for
2789Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2790can do about this. Check your PYTHONPATH environment variable!
2791
2792- Python bytecode files (*.pyc and *.pyo) are not compatible between
2793releases.
2794
2795
2796Overview of Changes Since 1.6
2797-----------------------------
2798
2799There are many new modules (including brand new XML support through
2800the xml package, and i18n support through the gettext module); a list
2801of all new modules is included below. Lots of bugs have been fixed.
2802
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002803The process for making major new changes to the language has changed
2804since Python 1.6. Enhancements must now be documented by a Python
2805Enhancement Proposal (PEP) before they can be accepted.
2806
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002807There are several important syntax enhancements, described in more
2808detail below:
2809
2810 - Augmented assignment, e.g. x += 1
2811
2812 - List comprehensions, e.g. [x**2 for x in range(10)]
2813
2814 - Extended import statement, e.g. import Module as Name
2815
2816 - Extended print statement, e.g. print >> file, "Hello"
2817
2818Other important changes:
2819
2820 - Optional collection of cyclical garbage
2821
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002822Python Enhancement Proposal (PEP)
2823---------------------------------
2824
2825PEP stands for Python Enhancement Proposal. A PEP is a design
2826document providing information to the Python community, or describing
2827a new feature for Python. The PEP should provide a concise technical
2828specification of the feature and a rationale for the feature.
2829
2830We intend PEPs to be the primary mechanisms for proposing new
2831features, for collecting community input on an issue, and for
2832documenting the design decisions that have gone into Python. The PEP
2833author is responsible for building consensus within the community and
2834documenting dissenting opinions.
2835
2836The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002837
2838Augmented Assignment
2839--------------------
2840
2841This must have been the most-requested feature of the past years!
2842Eleven new assignment operators were added:
2843
Guido van Rossume905e952000-09-05 12:42:46 +00002844 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002845
2846For example,
2847
2848 A += B
2849
2850is similar to
2851
2852 A = A + B
2853
2854except that A is evaluated only once (relevant when A is something
2855like dict[index].attr).
2856
2857However, if A is a mutable object, A may be modified in place. Thus,
2858if A is a number or a string, A += B has the same effect as A = A+B
2859(except A is only evaluated once); but if a is a list, A += B has the
2860same effect as A.extend(B)!
2861
2862Classes and built-in object types can override the new operators in
2863order to implement the in-place behavior; the not-in-place behavior is
2864used automatically as a fallback when an object doesn't implement the
2865in-place behavior. For classes, the method name is derived from the
2866method name for the corresponding not-in-place operator by inserting
2867an 'i' in front of the name, e.g. __iadd__ implements in-place
2868__add__.
2869
2870Augmented assignment was implemented by Thomas Wouters.
2871
2872
2873List Comprehensions
2874-------------------
2875
2876This is a flexible new notation for lists whose elements are computed
2877from another list (or lists). The simplest form is:
2878
2879 [<expression> for <variable> in <sequence>]
2880
Guido van Rossum56db0952000-09-06 23:34:25 +00002881For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002882This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002883
2884You can also add a condition:
2885
2886 [<expression> for <variable> in <sequence> if <condition>]
2887
2888For example, [w for w in words if w == w.lower()] would yield the list
2889of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002890than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002891
2892You can also have nested for loops and more than one 'if' clause. For
2893example, here's a function that flattens a sequence of sequences::
2894
2895 def flatten(seq):
2896 return [x for subseq in seq for x in subseq]
2897
2898 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2899
2900This prints
2901
2902 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2903
2904List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002905Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002906
2907
2908Extended Import Statement
2909-------------------------
2910
2911Many people have asked for a way to import a module under a different
2912name. This can be accomplished like this:
2913
2914 import foo
2915 bar = foo
2916 del foo
2917
2918but this common idiom gets old quickly. A simple extension of the
2919import statement now allows this to be written as follows:
2920
2921 import foo as bar
2922
2923There's also a variant for 'from ... import':
2924
2925 from foo import bar as spam
2926
2927This also works with packages; e.g. you can write this:
2928
2929 import test.regrtest as regrtest
2930
2931Note that 'as' is not a new keyword -- it is recognized only in this
2932context (this is only possible because the syntax for the import
2933statement doesn't involve expressions).
2934
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002935Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002936
2937
2938Extended Print Statement
2939------------------------
2940
2941Easily the most controversial new feature, this extension to the print
2942statement adds an option to make the output go to a different file
2943than the default sys.stdout.
2944
2945For example, to write an error message to sys.stderr, you can now
2946write:
2947
2948 print >> sys.stderr, "Error: bad dog!"
2949
2950As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002951evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002952
2953 print >> None, "Hello world"
2954
2955is equivalent to
2956
2957 print "Hello world"
2958
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002959Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002960
2961
2962Optional Collection of Cyclical Garbage
2963---------------------------------------
2964
2965Python is now equipped with a garbage collector that can hunt down
2966cyclical references between Python objects. It's no replacement for
2967reference counting; in fact, it depends on the reference counts being
2968correct, and decides that a set of objects belong to a cycle if all
2969their reference counts can be accounted for from their references to
2970each other. This devious scheme was first proposed by Eric Tiedemann,
2971and brought to implementation by Neil Schemenauer.
2972
2973There's a module "gc" that lets you control some parameters of the
2974garbage collection. There's also an option to the configure script
2975that lets you enable or disable the garbage collection. In 2.0b1,
2976it's on by default, so that we (hopefully) can collect decent user
2977experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002978performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002979off by default in the final 2.0 release.
2980
2981
2982Smaller Changes
2983---------------
2984
2985A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2986map(None, seq1, seq2, ...) when the sequences have the same length;
2987i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2988the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002989zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002990
2991sys.version_info is a tuple (major, minor, micro, level, serial).
2992
2993Dictionaries have an odd new method, setdefault(key, default).
2994dict.setdefault(key, default) returns dict[key] if it exists; if not,
2995it sets dict[key] to default and returns that value. Thus:
2996
2997 dict.setdefault(key, []).append(item)
2998
2999does the same work as this common idiom:
3000
3001 if not dict.has_key(key):
3002 dict[key] = []
3003 dict[key].append(item)
3004
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003005There are two new variants of SyntaxError that are raised for
3006indentation-related errors: IndentationError and TabError.
3007
3008Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3009escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003010
3011The limits on the size of expressions and file in Python source code
3012have been raised from 2**16 to 2**32. Previous versions of Python
3013were limited because the maximum argument size the Python VM accepted
3014was 2**16. This limited the size of object constructor expressions,
3015e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3016limit was raised thanks to a patch by Charles Waldman that effectively
3017fixes the problem. It is now much more likely that you will be
3018limited by available memory than by an arbitrary limit in Python.
3019
3020The interpreter's maximum recursion depth can be modified by Python
3021programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3022limit is the maximum number of recursive calls that can be made by
3023Python code. The limit exists to prevent infinite recursion from
3024overflowing the C stack and causing a core dump. The default value is
30251000. The maximum safe value for a particular platform can be found
3026by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003027
3028New Modules and Packages
3029------------------------
3030
3031atexit - for registering functions to be called when Python exits.
3032
3033imputil - Greg Stein's alternative API for writing custom import
3034hooks.
3035
3036pyexpat - an interface to the Expat XML parser, contributed by Paul
3037Prescod.
3038
3039xml - a new package with XML support code organized (so far) in three
3040subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3041would fill a volume. There's a special feature whereby a
3042user-installed package named _xmlplus overrides the standard
3043xmlpackage; this is intended to give the XML SIG a hook to distribute
3044backwards-compatible updates to the standard xml package.
3045
3046webbrowser - a platform-independent API to launch a web browser.
3047
3048
Guido van Rossume905e952000-09-05 12:42:46 +00003049Changed Modules
3050---------------
3051
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003052array -- new methods for array objects: count, extend, index, pop, and
3053remove
3054
3055binascii -- new functions b2a_hex and a2b_hex that convert between
3056binary data and its hex representation
3057
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003058calendar -- Many new functions that support features including control
3059over which day of the week is the first day, returning strings instead
3060of printing them. Also new symbolic constants for days of week,
3061e.g. MONDAY, ..., SUNDAY.
3062
3063cgi -- FieldStorage objects have a getvalue method that works like a
3064dictionary's get method and returns the value attribute of the object.
3065
3066ConfigParser -- The parser object has new methods has_option,
3067remove_section, remove_option, set, and write. They allow the module
3068to be used for writing config files as well as reading them.
3069
3070ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003071optionally support the RFC 959 REST command.
3072
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003073gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003074
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003075httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3076the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003077
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003078locale -- implement getdefaultlocale for Win32 and Macintosh
3079
3080marshal -- no longer dumps core when marshaling deeply nested or
3081recursive data structures
3082
3083os -- new functions isatty, seteuid, setegid, setreuid, setregid
3084
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003085os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3086support under Unix.
3087
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003088os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003089
3090os.path -- fix semantics of os.path.commonprefix
3091
3092smtplib -- support for sending very long messages
3093
3094socket -- new function getfqdn()
3095
3096readline -- new functions to read, write and truncate history files.
3097The readline section of the library reference manual contains an
3098example.
3099
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003100select -- add interface to poll system call
3101
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003102shutil -- new copyfileobj function
3103
3104SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3105HTTP server.
3106
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003107Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003108
3109urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003110e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003111
3112whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003113
3114
3115Obsolete Modules
3116----------------
3117
3118None. However note that 1.6 made a whole slew of modules obsolete:
3119stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3120poly, zmod, strop, util, whatsound.
3121
3122
3123Changed, New, Obsolete Tools
3124----------------------------
3125
Tim Peters8b092332000-09-05 20:15:25 +00003126None.
Guido van Rossume905e952000-09-05 12:42:46 +00003127
3128
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003129C-level Changes
3130---------------
3131
3132Several cleanup jobs were carried out throughout the source code.
3133
3134All C code was converted to ANSI C; we got rid of all uses of the
3135Py_PROTO() macro, which makes the header files a lot more readable.
3136
3137Most of the portability hacks were moved to a new header file,
3138pyport.h; several other new header files were added and some old
3139header files were removed, in an attempt to create a more rational set
3140of header files. (Few of these ever need to be included explicitly;
3141they are all included by Python.h.)
3142
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003143Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003144and Win64, especially for the new Intel Itanium processor. Mick also
3145added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003146
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003147The C APIs to return an object's size have been update to consistently
3148use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3149previous versions, the abstract interfaces used PyXXX_Length and the
3150concrete interfaces used PyXXX_Size. The old names,
3151e.g. PyObject_Length, are still available for backwards compatibility
3152at the API level, but are deprecated.
3153
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003154The PyOS_CheckStack function has been implemented on Windows by
3155Fredrik Lundh. It prevents Python from failing with a stack overflow
3156on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003157
3158The GC changes resulted in creation of two new slots on object,
3159tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003160the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003161
3162The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003163C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003164
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003165PyErr_Format has been updated to automatically calculate the size of
3166the buffer needed to hold the formatted result string. This change
3167prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003168
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003169New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003170
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003171PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3172that are the same as their non-Ex counterparts except they take an
3173extra flag argument that tells them to close the file when done.
3174
3175XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003176
Tim Peters8b092332000-09-05 20:15:25 +00003177
3178Windows Changes
3179---------------
3180
3181New popen2/popen3/peopen4 in os module (see Changed Modules above).
3182
3183os.popen is much more usable on Windows 95 and 98. See Microsoft
3184Knowledge Base article Q150956. The Win9x workaround described there
3185is implemented by the new w9xpopen.exe helper in the root of your
3186Python installation. Note that Python uses this internally; it is not
3187a standalone program.
3188
3189Administrator privileges are no longer required to install Python
3190on Windows NT or Windows 2000. If you have administrator privileges,
3191Python's registry info will be written under HKEY_LOCAL_MACHINE.
3192Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003193under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003194uses of Python, but will prevent some advanced uses from working
3195(for example, running a Python script as an NT service, or possibly
3196from CGI).
3197
3198[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3199installer; instead, it installs the needed Tcl/Tk files directly in the
3200Python directory. If you already have a Tcl/Tk installation, this
3201wastes some disk space (about 4 Megs) but avoids problems with
3202conflicting Tcl/Tk installations, and makes it much easier for Python
3203to ensure that Tcl/Tk can find all its files.
3204
3205[This was new in 1.6] The Windows installer now installs by default in
3206\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3207
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003208
3209Updates to the changes between 1.5.2 and 1.6
3210--------------------------------------------
3211
3212The 1.6 NEWS file can't be changed after the release is done, so here
3213is some late-breaking news:
3214
3215New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3216and changes to getlocale() and setlocale().
3217
3218The new module is now enabled per default.
3219
3220It is not true that the encodings codecs cannot be used for normal
3221strings: the string.encode() (which is also present on 8-bit strings
3222!) allows using them for 8-bit strings too, e.g. to convert files from
3223cp1252 (Windows) to latin-1 or vice-versa.
3224
3225Japanese codecs are available from Tamito KAJIYAMA:
3226http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3227
3228
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003229======================================================================