blob: fd552ed4af59c5cdecd0f46cfdf2bfbb9d142982 [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
Tim Petersaf8446f2001-12-21 21:36:50 +000029Tools/Demos
30
31Build
32
33C API
34
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000035- The "u#" parser marker will now pass through Unicode object as-is
36 without going through the buffer API.
37
Martin v. Löwis7198a522002-01-01 19:59:11 +000038- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
39
Tim Peters10a3bb52001-12-25 19:07:38 +000040- An old #define of ANY as void has been removed from pyport.h. This
41 hasn't been used since Python's pre-ANSI days, and the #define has
42 been marked as obsolete since then. SF bug 495548 says it created
43 conflicts with other packages, so keeping it around wasn't harmless.
44
Tim Petersaf8446f2001-12-21 21:36:50 +000045- Because Python's magic number scheme broke on January 1st, we decided
46 to stop Python development. Thanks for all the fish!
47
48New platforms
49
Martin v. Löwisa6e97582002-01-01 18:41:33 +000050- GNU/Hurd is now supported.
51
Tim Petersaf8446f2001-12-21 21:36:50 +000052Tests
53
54Windows
55
56Mac
57
58
Tim Peters909c0912001-12-14 23:16:18 +000059What's New in Python 2.2 final?
60Release date: 21-Dec-2001
61===============================
62
63Type/class unification and new-style classes
64
Barry Warsaw52acb492001-12-21 20:04:22 +000065- pickle.py, cPickle: allow pickling instances of new-style classes
66 with a custom metaclass.
67
Tim Peters909c0912001-12-14 23:16:18 +000068Core and builtins
69
Barry Warsaw52acb492001-12-21 20:04:22 +000070- weakref proxy object: when comparing, unwrap both arguments if both
71 are proxies.
72
Tim Peters909c0912001-12-14 23:16:18 +000073Extension modules
74
Barry Warsaw52acb492001-12-21 20:04:22 +000075- binascii.b2a_base64(): fix a potential buffer overrun when encoding
76 very short strings.
77
78- cPickle: the obscure "fast" mode was suspected of causing stack
79 overflows on the Mac. Hopefully fixed this by setting the recursion
80 limit much smaller. If the limit is too low (it only affects
81 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
82 when compiling cPickle.c (or in pyconfig.h).
83
Tim Peters909c0912001-12-14 23:16:18 +000084Library
85
Barry Warsaw52acb492001-12-21 20:04:22 +000086- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
87 close or delete time).
88
89- rfc822.py: fixed a bug where the address '<>' was converted to None
90 instead of an empty string (also fixes the email.Utils module).
91
92- xmlrpclib.py: version 1.0.0; uses precision for doubles.
93
94- test suite: the pickle and cPickle tests were not executing any code
95 when run from the standard regresssion test.
96
Tim Peters909c0912001-12-14 23:16:18 +000097Tools/Demos
98
99Build
100
101C API
102
103New platforms
104
105Tests
106
107Windows
108
Barry Warsaw52acb492001-12-21 20:04:22 +0000109- distutils package: fixed broken Windows installers (bdist_wininst).
110
111- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
112 instances are deleted at process exit time.
113
114- socket.py: prevent mysterious warnings when socket instances are
115 deleted at process exit time.
116
117- posixmodule.c: fix a Windows crash with stat() of a filename ending
118 in backslash.
119
Tim Peters909c0912001-12-14 23:16:18 +0000120Mac
121
Barry Warsaw52acb492001-12-21 20:04:22 +0000122- The Carbon toolbox modules have been upgraded to Universal Headers
123 3.4, and experimental CoreGraphics and CarbonEvents modules have
124 been added. All only for framework-enabled MacOSX.
125
Tim Peters909c0912001-12-14 23:16:18 +0000126
Tim Peters6272dfd2001-12-13 19:34:00 +0000127What's New in Python 2.2c1?
128Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000129===========================
130
131Type/class unification and new-style classes
132
Barry Warsaw06557452001-12-14 20:47:12 +0000133- Guido's tutorial introduction to the new type/class features has
134 been extensively updated. See
135
136 http://www.python.org/2.2/descrintro.html
137
138 That remains the primary documentation in this area.
139
Guido van Rossum33bab012001-12-05 22:45:48 +0000140- Fixed a leak: instance variables declared with __slots__ were never
141 deleted!
142
Guido van Rossum4b800852001-12-03 00:54:52 +0000143- The "delete attribute" method of descriptor objects is called
144 __delete__, not __del__. In previous releases, it was mistakenly
145 called __del__, which created an unfortunate overloading condition
146 with finalizers. (The "get attribute" and "set attribute" methods
147 are still called __get__ and __set__, respectively.)
148
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000149- Some subtle issues with the super built-in were fixed:
150
151 (a) When super itself is subclassed, its __get__ method would still
152 return an instance of the base class (i.e., of super).
153
154 (b) super(C, C()).__class__ would return C rather than super. This
155 is confusing. To fix this, I decided to change the semantics of
156 super so that it only applies to code attributes, not to data
157 attributes. After all, overriding data attributes is not
158 supported anyway.
159
160 (c) The __get__ method didn't check whether the argument was an
161 instance of the type used in creation of the super instance.
162
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000163- Previously, hash() of an instance of a subclass of a mutable type
164 (list or dictionary) would return some value, rather than raising
165 TypeError. This has been fixed. Also, directly calling
166 dict.__hash__ and list.__hash__ now raises the same TypeError
167 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000168
Guido van Rossumd331cb52001-12-05 19:46:42 +0000169- New-style objects now support deleting their __dict__. This is for
170 all intents and purposes equivalent to assigning a brand new empty
171 dictionary, but saves space if the object is not used further.
172
Tim Petersb3c9af12001-11-17 00:21:57 +0000173Core and builtins
174
Tim Peters3caca232001-12-06 06:23:26 +0000175- -Qnew now works as documented in PEP 238: when -Qnew is passed on
176 the command line, all occurrences of "/" use true division instead
177 of classic division. See the PEP for details. Note that "all"
178 means all instances in library and 3rd-party modules, as well as in
179 your own code. As the PEP says, -Qnew is intended for use only in
180 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000181 Note that test_coercion.py in the standard Python test suite fails
182 under -Qnew; this is expected, and won't be repaired until true
183 division becomes the default (in the meantime, test_coercion is
184 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000185
Fred Drake6c01e252001-12-14 17:08:12 +0000186- complex() now only allows the first argument to be a string
187 argument, and raises TypeError if either the second arg is a string
188 or if the second arg is specified when the first is a string.
189
Tim Petersb3c9af12001-11-17 00:21:57 +0000190Extension modules
191
Martin v. Löwis560da622001-11-24 09:24:51 +0000192- gc.get_referents was renamed to gc.get_referrers.
193
Tim Petersb3c9af12001-11-17 00:21:57 +0000194Library
195
Tim Peters25059d32001-12-07 20:35:43 +0000196- Functions in the os.spawn() family now release the global interpreter
197 lock around calling the platform spawn. They should always have done
198 this, but did not before 2.2c1. Multithreaded programs calling
199 an os.spawn function with P_WAIT will no longer block all Python threads
200 until the spawned program completes. It's possible that some programs
201 relies on blocking, although more likely by accident than by design.
202
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000203- webbrowser defaults to netscape.exe on OS/2 now.
204
Martin v. Löwis652e1912001-11-25 14:50:56 +0000205- Tix.ResizeHandle exposes detach_widget, hide, and show.
206
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000207- The charset alias windows_1252 has been added.
208
Barry Warsaw06557452001-12-14 20:47:12 +0000209- types.StringTypes is a tuple containing the defined string types;
210 usually this will be (str, unicode), but if Python was compiled
211 without Unicode support it will be just (str,).
212
213- The pulldom and minidom modules were synchronized to PyXML.
214
Tim Petersb3c9af12001-11-17 00:21:57 +0000215Tools/Demos
216
Barry Warsaw06557452001-12-14 20:47:12 +0000217- A new script called Tools/scripts/google.py was added, which fires
218 off a search on Google.
219
Tim Petersb3c9af12001-11-17 00:21:57 +0000220Build
221
Barry Warsaw06557452001-12-14 20:47:12 +0000222- Note that release builds of Python should arrange to define the
223 preprocessor symbol NDEBUG on the command line (or equivalent).
224 In the 2.2 pre-release series we tried to define this by magic in
225 Python.h instead, but it proved to cause problems for extension
226 authors. The Unix, Windows and Mac builds now all define NDEBUG in
227 release builds via cmdline (or equivalent) instead. Ports to
228 other platforms should do likewise.
229
Jack Jansen1999ef42001-12-06 21:47:20 +0000230- It is no longer necessary to use --with-suffix when building on a
231 case-insensitive file system (such as Mac OS X HFS+). In the build
232 directory an extension is used, but not in the installed python.
233
Tim Petersb3c9af12001-11-17 00:21:57 +0000234C API
235
Tim Petersf582b822001-12-11 18:51:08 +0000236- New function PyDict_MergeFromSeq2() exposes the builtin dict
237 constructor's logic for updating a dictionary from an iterable object
238 producing key-value pairs.
239
Tim Peterscffed4b2001-11-29 03:26:37 +0000240- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000241 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000242 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
243 dump core in some bad cases. This has been repaired. As a result,
244 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
245 previously went unchallenged.
246
Tim Petersb3c9af12001-11-17 00:21:57 +0000247New platforms
248
249Tests
250
251Windows
252
253Mac
254
Jack Jansenffa260f2001-12-06 21:14:00 +0000255- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
256 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000257
Barry Warsaw06557452001-12-14 20:47:12 +0000258- Changed logic for finding python home in Mac OS X framework Pythons.
259 Now sys.executable points to the executable again, in stead of to
260 the shared library. The latter is used only for locating the python
261 home.
262
263
Tim Peters84362bc2001-10-19 17:55:30 +0000264What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000265Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000266===========================
267
268Type/class unification and new-style classes
269
Guido van Rossum3d27df02001-11-15 20:27:54 +0000270- Multiple inheritance mixing new-style and classic classes in the
271 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000272
273 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000274 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000275
276 The MRO (method resolution order) for each base class is respected
277 according to its kind, but the MRO for the derived class is computed
278 using new-style MRO rules if any base clase is a new-style class.
279 This needs to be documented.
280
Tim Petersa427a2b2001-10-29 22:25:45 +0000281- The new builtin dictionary() constructor, and dictionary type, have
282 been renamed to dict. This reflects a decade of common usage.
283
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000284- dict() now accepts an iterable object producing 2-sequences. For
285 example, dict(d.items()) == d for any dictionary d. The argument,
286 and the elements of the argument, can be any iterable objects.
287
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000288- New-style classes can now have a __del__ method, which is called
289 when the instance is deleted (just like for classic classes).
290
Guido van Rossum12d955c2001-10-26 14:56:06 +0000291- Assignment to object.__dict__ is now possible, for objects that are
292 instances of new-style classes that have a __dict__ (unless the base
293 class forbids it).
294
Guido van Rossumc8e56452001-10-22 00:43:43 +0000295- Methods of built-in types now properly check for keyword arguments
296 (formerly these were silently ignored). The only built-in methods
297 that take keyword arguments are __call__, __init__ and __new__.
298
Guido van Rossum86443212001-10-27 22:28:54 +0000299- The socket function has been converted to a type; see below.
300
Tim Peters84362bc2001-10-19 17:55:30 +0000301Core and builtins
302
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000303- Assignment to __debug__ raises SyntaxError at compile-time. This
304 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000305 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000306
Guido van Rossum12d955c2001-10-26 14:56:06 +0000307- Clarified the error messages for unsupported operands to an operator
308 (like 1 + '').
309
Tim Peters84362bc2001-10-19 17:55:30 +0000310Extension modules
311
Tim Peters5ebfd362001-11-13 23:11:19 +0000312- mmap has a new keyword argument, "access", allowing a uniform way for
313 both Windows and Unix users to create read-only, write-through and
314 copy-on-write memory mappings. This was previously possible only on
315 Unix. A new keyword argument was required to support this in a
316 uniform way because the mmap() signuatures had diverged across
317 platforms. Thanks to Jay T Miller for repairing this!
318
Tim Peters169ded02001-11-03 19:57:21 +0000319- By default, the gc.garbage list now contains only those instances in
320 unreachable cycles that have __del__ methods; in 2.1 it contained all
321 instances in unreachable cycles. "Instances" here has been generalized
322 to include instances of both new-style and old-style classes.
323
Guido van Rossum12d955c2001-10-26 14:56:06 +0000324- The socket module defines a new method for socket objects,
325 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000326 send() until all data has been sent. Also, the socket function has
327 been converted to a subclassable type, like list and tuple (etc.)
328 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000329
330- Various bugfixes to the curses module. There is now a test suite
331 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000332
Guido van Rossum692adf12001-10-30 03:03:03 +0000333- binascii.b2a_base64 no longer places an arbitrary restriction of 57
334 bytes on its input.
335
Tim Peters84362bc2001-10-19 17:55:30 +0000336Library
337
Tim Peters5ebfd362001-11-13 23:11:19 +0000338- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000339 convenience function.
340
Tim Peters75335872001-11-03 19:35:43 +0000341- Symbolic group names in regular expressions must be unique. For
342 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
343 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000344 Python 2.2 detects this error at regexp compilation time;
345 previously, the error went undetected, and results were
346 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
347 pattern.subn() methods have been rewritten in C. Also, an
348 experimental function/method finditer() has been added, which works
349 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000350
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000351- Tix exposes more commands through the classes DirSelectBox,
352 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
353 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
354 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
355
Tim Peters98791af2001-10-23 01:59:54 +0000356- Traceback objects are now scanned by cyclic garbage collection, so
357 cycles created by casual use of sys.exc_info() no longer cause
358 permanent memory leaks (provided garbage collection is enabled).
359
Guido van Rossum49192142001-10-24 20:51:44 +0000360- os.extsep -- a new variable needed by the RISCOS support. It is the
361 separator used by extensions, and is '.' on all platforms except
362 RISCOS, where it is '/'. There is no need to use this variable
363 unless you have a masochistic desire to port your code to RISCOS.
364
Barry Warsaw012852b2001-11-16 16:17:27 +0000365- mimetypes.py has optional support for non-standard, but commonly
366 found types. guess_type() and guess_extension() now accept an
367 optional `strict' flag, defaulting to true, which controls whether
368 recognize non-standard types or not. A few non-standard types we
369 know about have been added. Also, when run as a script, there are
370 new -l and -e options.
371
372- statcache is now deprecated.
373
374- email.Utils.formatdate() now produces the preferred RFC 2822 style
375 dates with numeric timezones (it used to produce obsolete dates
376 hard coded to "GMT" timezone). An optional `localtime' flag is
377 added to produce dates in the local timezone, with daylight savings
378 time properly taken into account.
379
380- In pickle and cPickle, instead of masking errors in load() by
381 transforming them into SystemError, we let the original exception
382 propagate out. Also, implement support for __safe_for_unpickling__
383 in pickle, as it already was supported in cPickle.
384
Tim Peters84362bc2001-10-19 17:55:30 +0000385Tools/Demos
386
387Build
388
Barry Warsaw012852b2001-11-16 16:17:27 +0000389- The dbm module is built using libdb1 if available. The bsddb module
390 is built with libdb3 if available.
391
392- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
393
Tim Peters84362bc2001-10-19 17:55:30 +0000394C API
395
Tim Peters1fc240e2001-10-26 05:06:50 +0000396- New function PySequence_Fast_GET_SIZE() returns the size of a non-
397 NULL result from PySequence_Fast(), more quickly than calling
398 PySequence_Size().
399
Barry Warsaw012852b2001-11-16 16:17:27 +0000400- New argument unpacking function PyArg_UnpackTuple() added.
401
402- New functions PyObject_CallFunctionObjArgs() and
403 PyObject_CallMethodObjArgs() have been added to make it more
404 convenient and efficient to call functions and methods from C.
405
406- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
407 possible that this will propagate errors it didn't before.
408
409- New function PyObject_CheckReadBuffer(), which returns true if its
410 argument supports the single-segment readable buffer interface.
411
Tim Peters84362bc2001-10-19 17:55:30 +0000412New platforms
413
Guido van Rossum86443212001-10-27 22:28:54 +0000414- We've finally confirmed that this release builds on HP-UX 11.00,
415 *with* threads, and passes the test suite.
416
Tim Peters7a33d8b2001-11-05 02:51:07 +0000417- Thanks to a series of patches from Michael Muller, Python may build
418 again under OS/2 Visual Age C++.
419
Guido van Rossum49192142001-10-24 20:51:44 +0000420- Updated RISCOS port by Dietmar Schwertberger.
421
Tim Peters84362bc2001-10-19 17:55:30 +0000422Tests
423
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000424- Added a test script for the curses module. It isn't run automatically;
425 regrtest.py must be run with '-u curses' to enable it.
426
Tim Peters84362bc2001-10-19 17:55:30 +0000427Windows
428
Barry Warsaw012852b2001-11-16 16:17:27 +0000429Mac
430
431- PythonScript has been moved to unsupported and is slated to be
432 removed completely in the next release.
433
434- It should now be possible to build applets that work on both OS9 and
435 OSX.
436
437- The core is now linked with CoreServices not Carbon; as a side
438 result, default 8bit encoding on OSX is now ASCII.
439
440- Python should now build on OSX 10.1.1
441
Tim Peters84362bc2001-10-19 17:55:30 +0000442
Tim Petersabf925f2001-09-28 21:53:42 +0000443What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000444Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000445===========================
446
447Type/class unification and new-style classes
448
Guido van Rossum687ae002001-10-15 22:03:32 +0000449- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000450 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000451 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000452 remains: the __dict__ of a new-style class is a read-only proxy; you
453 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000454 __defined__ attribute of new-style types no longer exists, for lack
455 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000456 future a __cache__ may be resurrected with a similar function, if I
457 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000458
Tim Peters1c9ca872001-10-04 06:43:12 +0000459- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
460 always returned None, even when there was a class docstring).
461
462- doctest now finds and runs docstrings attached to new-style classes,
463 class methods, static methods, and properties.
464
Guido van Rossum9074ef62001-10-16 21:34:49 +0000465Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000466
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000467- A very subtle syntactical pitfall in list comprehensions was fixed.
468 For example: [a+b for a in 'abc', for b in 'def']. The comma in
469 this example is a mistake. Previously, this would silently let 'a'
470 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
471 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
472 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
473 Note that [a for a in <singleton>] is a convoluted way to say
474 [<singleton>] anyway, so it's not like any expressiveness is lost.
475
Guido van Rossum9074ef62001-10-16 21:34:49 +0000476- getattr(obj, name, default) now only catches AttributeError, as
477 documented, rather than returning the default value for all
478 exceptions (which could mask bugs in a __getattr__ hook, for
479 example).
480
Fred Drakecb7a6b52001-10-22 18:41:51 +0000481- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000482 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000483 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000484 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000485
Guido van Rossum1c486092001-10-19 02:05:35 +0000486- unicode(obj) now behaves more like str(obj), accepting arbitrary
487 objects, and calling a __unicode__ method if it exists.
488 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000489 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000490
Barry Warsawf6fb1712001-10-19 05:35:40 +0000491- isinstance() now allows any object as the first argument and a
492 class, a type or something with a __bases__ tuple attribute for the
493 second argument. The second argument may also be a tuple of a
494 class, type, or something with __bases__, in which case isinstance()
495 will return true if the first argument is an instance of any of the
496 things contained in the second argument tuple. E.g.
497
498 isinstance(x, (A, B))
499
500 returns true if x is an instance of A or B.
501
Guido van Rossum9074ef62001-10-16 21:34:49 +0000502Extension modules
503
504- thread.start_new_thread() now returns the thread ID (previously None).
505
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000506- binascii has now two quopri support functions, a2b_qp and b2a_qp.
507
Guido van Rossumc524d952001-10-19 01:31:59 +0000508- readline now supports setting the startup_hook and the
509 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000510
Guido van Rossumc524d952001-10-19 01:31:59 +0000511- os and posix supports chroot(), setgroups() and unsetenv() where
512 available. The stat(), fstat(), statvfs() and fstatvfs() functions
513 now return "pseudo-sequences" -- the various fields can now be
514 accessed as attributes (e.g. os.stat("/").st_mtime) but for
515 backwards compatibility they also behave as a fixed-length sequence.
516 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000517 attributes.
518
519- time: localtime(), gmtime() and strptime() now return a
520 pseudo-sequence similar to the os.stat() return value, with
521 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000522
Guido van Rossum9074ef62001-10-16 21:34:49 +0000523- Decompression objects in the zlib module now accept an optional
524 second parameter to decompress() that specifies the maximum amount
525 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000526
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000527- optional SSL support in the socket module now exports OpenSSL
528 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
529 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000530 automatically seed its PRNG. Also, the keyfile and certfile
531 arguments to socket.ssl() are now optional.
532
533- posixmodule (and by extension, the os module on POSIX platforms) now
534 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000535
Guido van Rossum9074ef62001-10-16 21:34:49 +0000536Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000537
Tim Peters7402f792001-10-02 03:53:41 +0000538- doctest now excludes functions and classes not defined by the module
539 being tested, thanks to Tim Hochberg.
540
Fred Drakecb7a6b52001-10-22 18:41:51 +0000541- HotShot, a new profiler implemented using a C-based callback, has
542 been added. This substantially reduces the overhead of profiling,
543 but it is still quite preliminary. Support modules and
544 documentation will be added in upcoming releases (before 2.2 final).
545
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000546- profile now produces correct output in situations where an exception
547 raised in Python is cleared by C code (e.g. hasattr()). This used
548 to cause wrong output, including spurious claims of recursive
549 functions and attribution of time spent to the wrong function.
550
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000551 The code and documentation for the derived OldProfile and HotProfile
552 profiling classes was removed. The code hasn't worked for years (if
553 you tried to use them, they raised exceptions). OldProfile
554 intended to reproduce the behavior of the profiler Python used more
555 than 7 years ago, and isn't interesting anymore. HotProfile intended
556 to provide a faster profiler (but producing less information), and
557 that's a worthy goal we intend to meet via a different approach (but
558 without losing information).
559
Tim Peterscce092d2001-10-09 05:31:56 +0000560- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000561 a much better system-specific calibration constant. The constant can
562 now be specified in an instance constructor, or as a Profile class or
563 instance variable, instead of by editing profile.py's source code.
564 Calibration must still be done manually (see the docs for the profile
565 module).
566
567 Note that Profile.calibrate() must be overriden by subclasses.
568 Improving the accuracy required exploiting detailed knowledge of
569 profiler internals; the earlier method abstracted away the details
570 and measured a simplified model instead, but consequently computed
571 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000572
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000573- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000574 which indicates whether output is intended for the header 'Q'
575 encoding.
576
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000577- The SocketServer.ThreadingMixIn class now closes the request after
578 finish_request() returns. (Not when it errors out though.)
579
Barry Warsawf6fb1712001-10-19 05:35:40 +0000580- The nntplib module's NNTP.body() method has grown a `file' argument
581 to allow saving the message body to a file.
582
583- The email package has added a class email.Parser.HeaderParser which
584 only parses headers and does not recurse into the message's body.
585 Also, the module/class MIMEAudio has been added for representing
586 audio data (contributed by Anthony Baxter).
587
588- ftplib should be able to handle files > 2GB.
589
590- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
591 ON, and OFF.
592
Fred Drakecb7a6b52001-10-22 18:41:51 +0000593- xml.dom.minidom NodeList objects now support the length attribute
594 and item() method as required by the DOM specifications.
595
Guido van Rossumed554f62001-10-02 23:15:37 +0000596Tools/Demos
597
598- Demo/dns was removed. It no longer serves any purpose; a package
599 derived from it is now maintained by Anthony Baxter, see
600 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000601
Barry Warsawf6fb1712001-10-19 05:35:40 +0000602- The freeze tool has been made more robust, and two new options have
603 been added: -X and -E.
604
Tim Petersabf925f2001-09-28 21:53:42 +0000605Build
606
Barry Warsawf6fb1712001-10-19 05:35:40 +0000607- configure will use CXX in LINKCC if CXX is used to build main() and
608 the system requires to link a C++ main using the C++ compiler.
609
Tim Petersabf925f2001-09-28 21:53:42 +0000610C API
611
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000612- The documentation for the tp_compare slot is updated to require that
613 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
614 not correct. This is not yet enforced but will be enforced in
615 Python 2.3; even later, we may use -2 to indicate errors and +2 for
616 "NotImplemented". Right now, -1 should be used for an error return.
617
Tim Petersd38b1c72001-09-30 05:09:37 +0000618- PyLong_AsLongLong() now accepts int (as well as long) arguments.
619 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
620 as long) arguments.
621
Guido van Rossum3c288632001-10-16 21:13:49 +0000622- PyThread_start_new_thread() now returns a long int giving the thread
623 ID, if one can be calculated; it returns -1 for error, 0 if no
624 thread ID is calculated (this is an incompatible change, but only
625 the thread module used this API). This code has only really been
626 tested on Linux and Windows; other platforms please beware (and
627 report any bugs or strange behavior).
628
Guido van Rossum1c486092001-10-19 02:05:35 +0000629- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
630 input.
631
Tim Petersabf925f2001-09-28 21:53:42 +0000632New platforms
633
634Tests
635
636Windows
637
Tim Peters04cf1d32001-10-09 22:39:40 +0000638- Installer: If you install IDLE, and don't disable file-extension
639 registration, a new "Edit with IDLE" context (right-click) menu entry
640 is created for .py and .pyw files.
641
Tim Peters1ce3cf72001-10-01 17:58:40 +0000642- The signal module now supports SIGBREAK on Windows, thanks to Steven
643 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
644 action remains to call Win32 ExitProcess(). This can be changed via
645 signal.signal(). For example:
646
647 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
648 # (SIGINT) behavior.
649 import signal
650 signal.signal(signal.SIGBREAK,
651 signal.default_int_handler)
652
653 try:
654 while 1:
655 pass
656 except KeyboardInterrupt:
657 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
658 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
659 # program without the possibility for any Python-level cleanup).
660 print "Clean exit"
661
Tim Petersabf925f2001-09-28 21:53:42 +0000662
Tim Petersb07352e2001-09-08 01:25:47 +0000663What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000664Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000665===========================
666
Guido van Rossum808eea72001-09-25 04:15:41 +0000667Type/class unification and new-style classes
668
669- pydoc and inspect are now aware of new-style classes;
670 e.g. help(list) at the interactive prompt now shows proper
671 documentation for all operations on list objects.
672
673- Applications using Jim Fulton's ExtensionClass module can now safely
674 be used with Python 2.2. In particular, Zope 2.4.1 now works with
675 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
676 examples also work again. It is hoped that Gtk and Boost also work
677 with 2.2a4 and beyond. (If you can confirm this, please write
678 webmaster@python.org; if there are still problems, please open a bug
679 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000680
Tim Peters66c1a522001-09-24 21:17:50 +0000681- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
682 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
683 in the constructed property object. fget, fset and fdel weren't
684 discoverable from Python in 2.2a3. __doc__ is new, and allows to
685 associate a docstring with a property.
686
Guido van Rossum808eea72001-09-25 04:15:41 +0000687- Comparison overloading is now more completely implemented. For
688 example, a str subclass instance can properly be compared to a str
689 instance, and it can properly overload comparison. Ditto for most
690 other built-in object types.
691
692- The repr() of new-style classes has changed; instead of <type
693 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
694 *except* for built-in types, which are still rendered as <type
695 'Foo'> (to avoid upsetting existing code that might parse or
696 otherwise rely on repr() of certain type objects).
697
698- The repr() of new-style objects is now always <Foo object at XXX>;
699 previously, it was sometimes <Foo instance at XXX>.
700
701- For new-style classes, what was previously called __getattr__ is now
702 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000703 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000704 one in classic classes is defined which is called only if regular
705 attribute access raises AttributeError; to catch *all* attribute
706 access, you can use __getattribute__ (for new-style classes). If
707 both are defined, __getattribute__ is called first, and if it raises
708 AttributeError, __getattr__ is called.
709
710- The __class__ attribute of new-style objects can be assigned to.
711 The new class must have the same C-level object layout as the old
712 class.
713
714- The builtin file type can be subclassed now. In the usual pattern,
715 "file" is the name of the builtin type, and file() is a new builtin
716 constructor, with the same signature as the builtin open() function.
717 file() is now the preferred way to open a file.
718
719- Previously, __new__ would only see sequential arguments passed to
720 the type in a constructor call; __init__ would see both sequential
721 and keyword arguments. This made no sense whatsoever any more, so
722 now both __new__ and __init__ see all arguments.
723
724- Previously, hash() applied to an instance of a subclass of str or
725 unicode always returned 0. This has been repaired.
726
727- Previously, an operation on an instance of a subclass of an
728 immutable type (int, long, float, complex, tuple, str, unicode),
729 where the subtype didn't override the operation (and so the
730 operation was handled by the builtin type), could return that
731 instance instead a value of the base type. For example, if s was of
732 a str sublass type, s[:] returned s as-is. Now it returns a str
733 with the same value as s.
734
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000735- Provisional support for pickling new-style objects has been added.
736
Guido van Rossum808eea72001-09-25 04:15:41 +0000737Core
738
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000739- file.writelines() now accepts any iterable object producing strings.
740
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000741- PyUnicode_FromEncodedObject() now works very much like
742 PyObject_Str(obj) in that it tries to use __str__/tp_str
743 on the object if the object is not a string or buffer. This
744 makes unicode() behave like str() when applied to non-string/buffer
745 objects.
746
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000747- PyFile_WriteObject now passes Unicode objects to the file's write
748 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000749 of a print statement must support Unicode objects, i.e. they must
750 at least convert them into ASCII strings.
751
Guido van Rossum624c8af2001-09-18 15:21:04 +0000752- Thread scheduling on Solaris should be improved; it is no longer
753 necessary to insert a small sleep at the start of a thread in order
754 to let other runnable threads be scheduled.
755
Tim Petersb07352e2001-09-08 01:25:47 +0000756Library
757
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000758- StringIO.StringIO instances and cStringIO.StringIO instances support
759 read character buffer compatible objects for their .write() methods.
760 These objects are converted to strings and then handled as such
761 by the instances.
762
Barry Warsaw2f600732001-09-24 04:28:10 +0000763- The "email" package has been added. This is basically a port of the
764 mimelib package <http://sf.net/projects/mimelib> with API changes
765 and some implementations updated to use iterators and generators.
766
Tim Peters8a9c2842001-09-22 21:30:22 +0000767- difflib.ndiff() and difflib.Differ.compare() are generators now. This
768 restores the ability of Tools/scripts/ndiff.py to start producing output
769 before the entire comparison is complete.
770
Barry Warsaw58b072d2001-09-22 04:44:21 +0000771- StringIO.StringIO instances and cStringIO.StringIO instances support
772 iteration just like file objects (i.e. their .readline() method is
773 called for each iteration until it returns an empty string).
774
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000775- The codecs module has grown four new helper APIs to access
776 builtin codecs: getencoder(), getdecoder(), getreader(),
777 getwriter().
778
Guido van Rossum624c8af2001-09-18 15:21:04 +0000779- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
780 simplifies writing XML RPC servers.
781
Barry Warsaw647d5e82001-09-28 17:01:02 +0000782- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000783 after interpretation of symbolic links. On non-Unix systems, this
784 is an alias for os.path.abspath().
785
Tim Peters16a77ad2001-09-08 04:00:12 +0000786- operator.indexOf() (PySequence_Index() in the C API) now works with any
787 iterable object.
788
Guido van Rossum624c8af2001-09-18 15:21:04 +0000789- smtplib now supports various authentication and security features of
790 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000791
Guido van Rossum624c8af2001-09-18 15:21:04 +0000792- hmac: a new module implementing keyed hashing for message
793 authentication.
794
795- mimetypes now recognizes more extensions and file types. At the
796 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000797
Guido van Rossum624c8af2001-09-18 15:21:04 +0000798- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000799 Python 2.2 bytecode generation. It has also been promoted from a
800 Tool to a standard library package. (Tools/compiler still exists as
801 a sample driver.)
802
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000803Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000804
Tim Petersb07352e2001-09-08 01:25:47 +0000805Build
806
Guido van Rossum624c8af2001-09-18 15:21:04 +0000807- Large file support (LFS) is now automatic when the platform supports
808 it; no more manual configuration tweaks are needed. On Linux, at
809 least, it's possible to have a system whose C library supports large
810 files but whose kernel doesn't; in this case, large file support is
811 still enabled but doesn't do you any good unless you upgrade your
812 kernel or share your Python executable with another system whose
813 kernel has large file support.
814
815- The configure script now supplies plausible defaults in a
816 cross-compilation environment. This doesn't mean that the supplied
817 values are always correct, or that cross-compilation now works
818 flawlessly -- but it's a first step (and it shuts up most of
819 autoconf's warnings about AC_TRY_RUN).
820
821- The Unix build is now a bit less chatty, courtesy of the parser
822 generator. The build is completely silent (except for errors) when
823 using "make -s", thanks to a -q option to setup.py.
824
Tim Petersb07352e2001-09-08 01:25:47 +0000825C API
826
Guido van Rossum624c8af2001-09-18 15:21:04 +0000827- The "structmember" API now supports some new flag bits to deny read
828 and/or write access to attributes in restricted execution mode.
829
Tim Petersb07352e2001-09-08 01:25:47 +0000830New platforms
831
Guido van Rossum624c8af2001-09-18 15:21:04 +0000832- Compaq's iPAQ handheld, running the "familiar" Linux distribution
833 (http://familiar.handhelds.org).
834
Tim Petersb07352e2001-09-08 01:25:47 +0000835Tests
836
Tim Peters8a9c2842001-09-22 21:30:22 +0000837- The "classic" standard tests, which work by comparing stdout to
838 an expected-output file under Lib/test/output/, no longer stop at
839 the first mismatch. Instead the test is run to completion, and a
840 variant of ndiff-style comparison is used to report all differences.
841 This is much easier to understand than the previous style of reporting.
842
843- The unittest-based standard tests now use regrtest's test_main()
844 convention, instead of running as a side-effect of merely being
845 imported. This allows these tests to be run in more natural and
846 flexible ways as unittests, outside the regrtest framework.
847
848- regrtest.py is much better integrated with unittest and doctest now,
849 especially in regard to reporting errors.
850
Tim Petersb07352e2001-09-08 01:25:47 +0000851Windows
852
Guido van Rossum624c8af2001-09-18 15:21:04 +0000853- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000854 that support it (NTFS under Windows 2000). See "What's New in
855 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000856
Tim Petersb07352e2001-09-08 01:25:47 +0000857
Tim Petersedc99312001-08-22 21:36:50 +0000858What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000859Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000860===========================
861
862Core
863
Tim Peters9fffa3e2001-09-04 05:14:19 +0000864- Conversion of long to float now raises OverflowError if the long is too
865 big to represent as a C double.
866
Tim Peters32f453e2001-09-03 08:35:41 +0000867- The 3-argument builtin pow() no longer allows a third non-None argument
868 if either of the first two arguments is a float, or if both are of
869 integer types and the second argument is negative (in which latter case
870 the arguments are converted to float, so this is really the same
871 restriction).
872
Tim Peters5d2b77c2001-09-03 05:47:38 +0000873- The builtin dir() now returns more information, and sometimes much
874 more, generally naming all attributes of an object, and all attributes
875 reachable from the object via its class, and from its class's base
876 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
877 an empty list. In 2.2a3,
878
879 >>> dir([])
880 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
881 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
882 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
883 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
884 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
885 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
886 'reverse', 'sort']
887
888 dir(module) continues to return only the module's attributes, though.
889
Tim Petersbdee63f2001-09-02 03:40:59 +0000890- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000891 than raising OverflowError. This is a partial implementation of PEP
892 237. You can use -Wdefault::OverflowWarning to enable a warning for
893 this situation, and -Werror::OverflowWarning to revert to the old
894 OverflowError exception.
895
Guido van Rossum61c345f2001-09-04 03:26:15 +0000896- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000897 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000898 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
899 -Qold, meaning the / operator has its classic meaning and no
900 warnings are issued. Using -Qwarn issues a run-time warning about
901 all uses of classic division for int and long arguments; -Qwarnall
902 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000903 (for use with fixdiv.py).
904 [Note: the remainder of this paragraph (preserved below) became
905 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
906 <obsolete>
907 Using -Qnew is questionable; it turns on new division by default, but
908 only in the __main__ module. You can usefully combine -Qwarn or
909 -Qwarnall and -Qnew: this gives the __main__ module new division, and
910 warns about classic division everywhere else.
911 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000912
Tim Petersbdee63f2001-09-02 03:40:59 +0000913- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000914 long, float, str, unicode, and tuple. (The types complex, list and
915 dictionary can also be subclassed; this was introduced earlier.)
916 Note that restrictions apply when subclassing immutable built-in
917 types: you can only affect the value of the instance by overloading
918 __new__. You can add mutable attributes, and the subclass instances
919 will have a __dict__ attribute, but you cannot change the "value"
920 (as implemented by the base class) of an immutable subclass instance
921 once it is created.
922
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000923- The dictionary constructor now takes an optional argument, a
924 mapping-like object, and initializes the dictionary from its
925 (key, value) pairs.
926
Tim Petersbdee63f2001-09-02 03:40:59 +0000927- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000928 "cooperative super calls" in a multiple inheritance setting. For an
929 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
930
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000931- A new built-in type, property, has been added. This enables the
932 creation of "properties". These are attributes implemented by
933 getter and setter functions (or only one of these for read-only or
934 write-only attributes), without the need to override __getattr__.
935 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000936
Tim Petersbdee63f2001-09-02 03:40:59 +0000937- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000938 liberalized, to allow leading zeroes. Examples of literals now
939 legal that were SyntaxErrors before:
940
941 00.0 0e3 0100j 07.5 00000000000000000008.
942
Tim Petersbdee63f2001-09-02 03:40:59 +0000943- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000944 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
945
Tim Petersedc99312001-08-22 21:36:50 +0000946Library
947
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000948- telnetlib includes symbolic names for the options, and support for
949 setting an option negotiation callback.
950
Tim Petersa40c7932001-09-05 22:36:56 +0000951- The new C standard no longer requires that math libraries set errno to
952 ERANGE on overflow. For platform libraries that exploit this new
953 freedom, Python's overflow-checking was wholly broken. A new overflow-
954 checking scheme attempts to repair that, but may not be reliable on all
955 platforms (C doesn't seem to provide anything both useful and portable
956 in this area anymore).
957
Martin v. Löwis44f86962001-09-05 13:44:54 +0000958- Asynchronous timeout actions are available through the new class
959 threading.Timer.
960
Tim Peters78526162001-09-05 00:53:45 +0000961- math.log and math.log10 now return sensible results for even huge
962 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
963
Tim Petersbdee63f2001-09-02 03:40:59 +0000964- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000965 currently held. See the docs for the imp module.
966
Tim Petersbdee63f2001-09-02 03:40:59 +0000967- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000968 dumps containing ints written on platforms where Python ints are 8 bytes.
969 When read on a box where Python ints are 4 bytes, such values are
970 converted to Python longs.
971
Tim Petersbdee63f2001-09-02 03:40:59 +0000972- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000973 code objects is no longer allowed. This plugs a security hole.
974
Steve Purcell6091cd62001-09-06 16:05:17 +0000975- unittest.TestResult instances no longer store references to tracebacks
976 generated by test failures. This prevents unexpected dangling references
977 to objects that should be garbage collected between tests.
978
Tim Petersedc99312001-08-22 21:36:50 +0000979Tools
980
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000981- Tools/scripts/fixdiv.py has been added which can be used to fix
982 division operators as per PEP 238.
983
Tim Petersedc99312001-08-22 21:36:50 +0000984Build
985
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000986- If you are an adventurous person using Mac OS X you may want to look at
987 Mac/OSX. There is a Makefile there that will build Python as a real Mac
988 application, which can be used for experimenting with Carbon or Cocoa.
989 Discussion of this on pythonmac-sig, please.
990
Tim Peters7eea37e2001-09-04 22:08:56 +0000991C API
992
993- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000994
Tim Peters9fffa3e2001-09-04 05:14:19 +0000995- Note that PyLong_AsDouble can fail! This has always been true, but no
996 callers checked for it. It's more likely to fail now, because overflow
997 errors are properly detected now. The proper way to check:
998
999 double x = PyLong_AsDouble(some_long_object);
1000 if (x == -1.0 && PyErr_Occurred()) {
1001 /* The conversion failed. */
1002 }
1003
Tim Petersbdee63f2001-09-02 03:40:59 +00001004- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001005 compile but will not participate in GC. To upgrade an extension
1006 module:
1007
1008 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001009
Neil Schemenauer4042c692001-08-30 15:38:01 +00001010 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1011 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001012
Neil Schemenauer4042c692001-08-30 15:38:01 +00001013 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1014 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001015
Neil Schemenauer4042c692001-08-30 15:38:01 +00001016 - remove PyGC_HEAD_SIZE from object size calculations
1017
1018 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1019
Tim Petersbdee63f2001-09-02 03:40:59 +00001020- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001021 These can be used safely to construct string objects from a
1022 sprintf-style format string (similar to the format string supported
1023 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001024
Tim Petersedc99312001-08-22 21:36:50 +00001025New platforms
1026
Tim Petersb7da0902001-09-02 23:01:43 +00001027- Stephen Hansen contributed patches sufficient to get a clean compile
1028 under Borland C (Windows), but he reports problems running it and ran
1029 out of time to complete the port. Volunteers? Expect a MemoryError
1030 when importing the types module; this is probably shallow, and
1031 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001032
Tim Petersedc99312001-08-22 21:36:50 +00001033Tests
1034
1035Windows
1036
Tim Peters6e13a562001-09-06 00:32:15 +00001037- Large file support is now enabled on Win32 platforms as well as on
1038 Win64. This means that, for example, you can use f.tell() and f.seek()
1039 to manipulate files larger than 2 gigabytes (provided you have enough
1040 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001041 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1042 filesize limit, and large file support makes no difference there.
1043 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1044 NTFS has no practical limit on file size, and files of any size can be
1045 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001046
Tim Petersbdee63f2001-09-02 03:40:59 +00001047- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001048 points to command.com (patch from Brian Quinlan).
1049
Tim Petersedc99312001-08-22 21:36:50 +00001050
Tim Peters20f51a72001-07-21 02:31:40 +00001051What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001052Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001053===========================
1054
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001055Build
1056
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001057- Tim Peters developed a brand new Windows installer using Wise 8.1,
1058 generously donated to us by Wise Solutions.
1059
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001060- configure supports a new option --enable-unicode, with the values
1061 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1062 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001063
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001064- A new configure option --enable-framework builds a Mac OS X framework,
1065 which "make frameworkinstall" will install. This provides a starting
1066 point for more mac-like functionality, join pythonmac-sig@python.org
1067 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001068
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001069- The NeXT platform is no longer supported.
1070
1071- The `new' module is now statically linked.
1072
Tim Peters0afb6092001-08-15 06:06:44 +00001073Tools
1074
1075- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001076 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001077 the module docstring for details.
1078
Tim Peters20f51a72001-07-21 02:31:40 +00001079Tests
1080
Tim Peters5e824c32001-08-12 22:25:01 +00001081- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001082 platforms, allowing to give clearer test result output. regrtest
1083 also has optional --use/-u switch to run normally disabled tests
1084 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001085
Tim Peters20f51a72001-07-21 02:31:40 +00001086- Several new tests in the standard test suite, with special thanks to
1087 Nick Mathewson.
1088
1089Core
1090
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001091- The floor division operator // has been added as outlined in PEP
1092 238. The / operator still provides classic division (and will until
1093 Python 3.0) unless "from __future__ import division" is included, in
1094 which case the / operator will provide true division. The operator
1095 module provides truediv() and floordiv() functions. Augmented
1096 assignment variants are included, as are the equivalent overloadable
1097 methods and C API methods. See the PEP for a full discussion:
1098 <http://python.sf.net/peps/pep-0238.html>
1099
Tim Peters6cd6a822001-08-17 22:11:27 +00001100- Future statements are now effective in simulated interactive shells
1101 (like IDLE). This should "just work" by magic, but read Michael
1102 Hudson's "Future statements in simulated shells" PEP 264 for full
1103 details: <http://python.sf.net/peps/pep-0264.html>.
1104
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001105- The type/class unification (PEP 252-253) was integrated into the
1106 trunk and is not so tentative any more (the exact specification of
1107 some features is still tentative). A lot of work has done on fixing
1108 bugs and adding robustness and features (performance still has to
1109 come a long way).
1110
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001111- Warnings about a mismatch in the Python API during extension import
1112 now use the Python warning framework (which makes it possible to
1113 write filters for these warnings).
1114
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001115- A function's __dict__ (aka func_dict) will now always be a
1116 dictionary. It used to be possible to delete it or set it to None,
1117 but now both actions raise TypeErrors. It is still legal to set it
1118 to a dictionary object. Getting func.__dict__ before any attributes
1119 have been assigned now returns an empty dictionary instead of None.
1120
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001121- A new command line option, -E, was added which disables the use of
1122 all environment variables, or at least those that are specifically
1123 significant to Python. Usually those have a name starting with
1124 "PYTHON". This was used to fix a problem where the tests fail if
1125 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1126 older distribution.
1127
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001128Library
1129
Tim Peters5e824c32001-08-12 22:25:01 +00001130- New class Differ and new functions ndiff() and restore() in difflib.py.
1131 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001132 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001133
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001134- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1135 value using the minimal quoting required for the value; more
1136 reliable than using xml.sax.saxutils.escape() for attribute values.
1137
1138- Readline completion support for cmd.Cmd was added.
1139
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001140- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1141
1142- Added function threading.BoundedSemaphore()
1143
1144- Added Ka-Ping Yee's cgitb.py module.
1145
1146- The `new' module now exposes the CO_xxx flags.
1147
Martin v. Löwis560da622001-11-24 09:24:51 +00001148- The gc module offers the get_referents function.
1149
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001150New platforms
1151
1152C API
1153
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001154- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1155 which provide a cross-platform implementations for the
1156 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1157 the standard sprintf() and vsprintf() C lib APIs, these versions
1158 apply bounds checking on the used buffer which enhances protection
1159 against buffer overruns.
1160
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001161- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001162 and extensions using different Unicode widths is rendered next to
1163 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001164 will result in an ImportError. Unicode extensions writers must make
1165 sure to check the Unicode width compatibility in their extensions by
1166 using at least one of the mangled Unicode APIs in the extension.
1167
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001168- Two new flags METH_NOARGS and METH_O are available in method definition
1169 tables to simplify implementation of methods with no arguments and a
1170 single untyped argument. Calling such methods is more efficient than
1171 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1172 deprecated.
1173
Tim Petersc1731372001-08-04 08:12:36 +00001174Windows
1175
1176- "import module" now compiles module.pyw if it exists and nothing else
1177 relevant is found.
1178
Tim Peters20f51a72001-07-21 02:31:40 +00001179
Guido van Rossum55a78992001-07-17 17:22:32 +00001180What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001181Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001182===========================
1183
1184Core
Tim Petersa814db52001-05-14 07:05:58 +00001185
Tim Peters6d6c1a32001-08-02 04:15:00 +00001186- TENTATIVELY, a large amount of code implementing much of what's
1187 described in PEP 252 (Making Types Look More Like Classes) and PEP
1188 253 (Subtyping Built-in Types) was added. This will be released
1189 with Python 2.2a1. Documentation will be provided separately
1190 through http://www.python.org/2.2/. The purpose of releasing this
1191 with Python 2.2a1 is to test backwards compatibility. It is
1192 possible, though not likely, that a decision is made not to release
1193 this code as part of 2.2 final, if any serious backwards
1194 incompapatibilities are found during alpha testing that cannot be
1195 repaired.
1196
Guido van Rossum55a78992001-07-17 17:22:32 +00001197- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001198 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001199 more 'yield' statements. See PEP 255. Since this adds a new
1200 keyword to the language, this feature must be enabled by including a
1201 future statement: "from __future__ import generators" (see PEP 236).
1202 Generators will become a standard feature in a future release
1203 (probably 2.3). Without this future statement, 'yield' remains an
1204 ordinary identifier, but a warning is issued each time it is used.
1205 (These warnings currently don't conform to the warnings framework of
1206 PEP 230; we intend to fix this in 2.2a2.)
1207
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001208- The UTF-16 codec was modified to be more RFC compliant. It will now
1209 only remove BOM characters at the start of the string and then
1210 only if running in native mode (UTF-16-LE and -BE won't remove a
1211 leading BMO character).
1212
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001213- Strings now have a new method .decode() to complement the already
1214 existing .encode() method. These two methods provide direct access
1215 to the corresponding decoders and encoders of the registered codecs.
1216
1217 To enhance the usability of the .encode() method, the special
1218 casing of Unicode object return values was dropped (Unicode objects
1219 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001220
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001221 Both methods will now return whatever the codec in charge of the
1222 requested encoding returns as object, e.g. Unicode codecs will
1223 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1224 will return u"äöü"). This enables codec writer to create codecs
1225 for various simple to use conversions.
1226
1227 New codecs were added to demonstrate these new features (the .encode()
1228 and .decode() columns indicate the type of the returned objects):
1229
1230 Name | .encode() | .decode() | Description
1231 ----------------------------------------------------------------------
1232 uu | string | string | UU codec (e.g. for email)
1233 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001234 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001235 zlib | string | string | zlib compression
1236 hex | string | string | 2-byte hex codec
1237 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1238
Mark Hammond2a0af792001-05-14 03:09:36 +00001239- Some operating systems now support the concept of a default Unicode
1240 encoding for file system operations. Notably, Windows supports 'mbcs'
1241 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001242 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001243 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001244
1245 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001246 functions that return filenames (such as os.listdir()) to return Python
1247 string objects pre-encoded using the default file system encoding for
1248 the platform. As this encoding is likely to be different from Python's
1249 default encoding, converting this name to a Unicode object before passing
1250 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001251 would attempt to use its default encoding (generally ASCII) rather than
1252 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001253
Tim Petersa814db52001-05-14 07:05:58 +00001254 In general, this change simply removes surprises when working with
1255 Unicode and the file system, making these operations work as you expect,
1256 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001257 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001258
Tim Peters61dff2b2001-05-08 15:43:37 +00001259- Float (and complex) literals in source code were evaluated to full
1260 precision only when running from a .py file; the same code loaded from a
1261 .pyc (or .pyo) file could suffer numeric differences starting at about the
1262 12th significant decimal digit. For example, on a machine with IEEE-754
1263 floating arithmetic,
1264
1265 x = 9007199254740992.0
1266 print long(x)
1267
1268 printed 9007199254740992 if run directly from .py, but 9007199254740000
1269 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1270 str(float) instead of repr(float) when building code objects. marshal
1271 now uses repr(float) instead, which should reproduce floats to full
1272 machine precision (assuming the platform C float<->string I/O conversion
1273 functions are of good quality).
1274
1275 This may cause floating-point results to change in some cases, and
1276 usually for the better, but may also cause numerically unstable
1277 algorithms to break.
1278
Tim Peters2f228e72001-05-13 00:19:31 +00001279- The implementation of dicts suffers fewer collisions, which has speed
1280 benefits. However, the order in which dict entries appear in dict.keys(),
1281 dict.values() and dict.items() may differ from previous releases for a
1282 given dict. Nothing is defined about this order, so no program should
1283 rely on it. Nevertheless, it's easy to write test cases that rely on the
1284 order by accident, typically because of printing the str() or repr() of a
1285 dict to an "expected results" file. See Lib/test/test_support.py's new
1286 sortdict(dict) function for a simple way to display a dict in sorted
1287 order.
1288
Tim Peters7a3bfc32001-06-12 01:22:22 +00001289- Many other small changes to dicts were made, resulting in faster
1290 operation along the most common code paths.
1291
Guido van Rossum10315822001-05-01 20:54:30 +00001292- Dictionary objects now support the "in" operator: "x in dict" means
1293 the same as dict.has_key(x).
1294
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001295- The update() method of dictionaries now accepts generic mapping
1296 objects. Specifically the argument object must support the .keys()
1297 and __getitem__() methods. This allows you to say, for example,
1298 {}.update(UserDict())
1299
Guido van Rossum10315822001-05-01 20:54:30 +00001300- Iterators were added; this is a generalized way of providing values
1301 to a for loop. See PEP 234. There's a new built-in function iter()
1302 to return an iterator. There's a new protocol to get the next value
1303 from an iterator using the next() method (in Python) or the
1304 tp_iternext slot (in C). There's a new protocol to get iterators
1305 using the __iter__() method (in Python) or the tp_iter slot (in C).
1306 Iterating (i.e. a for loop) over a dictionary generates its keys.
1307 Iterating over a file generates its lines.
1308
Tim Petersf553f892001-05-01 20:45:31 +00001309- The following functions were generalized to work nicely with iterator
1310 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001311 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001312 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1313 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001314 join() method of strings
1315 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001316 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1317 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001318 right-hand side of assignment statements with multiple targets, such as
1319 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001320
Tim Petersd85e1022001-05-11 21:51:48 +00001321- Accessing module attributes is significantly faster (for example,
1322 random.random or os.path or yourPythonModule.yourAttribute).
1323
Tim Peterse63415e2001-05-08 04:38:29 +00001324- Comparing dictionary objects via == and != is faster, and now works even
1325 if the keys and values don't support comparisons other than ==.
1326
Tim Peters95bf9392001-05-10 08:32:44 +00001327- Comparing dictionaries in ways other than == and != is slower: there were
1328 insecurities in the dict comparison implementation that could cause Python
1329 to crash if the element comparison routines for the dict keys and/or
1330 values mutated the dicts. Making the code bulletproof slowed it down.
1331
Tim Peterseb28ef22001-06-02 05:27:19 +00001332- Collisions in dicts are resolved via a new approach, which can help
1333 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001334 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001335 faster now. Thanks to Christian Tismer for pointing out the cause and
1336 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001337
Tim Peters52e155e2001-06-16 05:42:57 +00001338- repr() is much faster for large containers (dict, list, tuple).
1339
1340
Tim Petersa814db52001-05-14 07:05:58 +00001341Library
1342
Fred Drake960fdf92001-07-20 18:38:26 +00001343- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1344 were added to the string module. These a locale-indenpendent
1345 constants, unlike letters, lowercase, and uppercase. These are now
1346 use in appropriate locations in the standard library.
1347
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001348- The flags used in dlopen calls can now be configured using
1349 sys.setdlopenflags and queried using sys.getdlopenflags.
1350
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001351- Fredrik Lundh's xmlrpclib is now a standard library module. This
1352 provides full client-side XML-RPC support. In addition,
1353 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1354 one asyncore-based). Thanks to Eric Raymond for the documentation.
1355
Guido van Rossum643d3912001-07-05 14:46:25 +00001356- The xrange() object is simplified: it no longer supports slicing,
1357 repetition, comparisons, efficient 'in' checking, the tolist()
1358 method, or the start, stop and step attributes. See PEP 260.
1359
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001360- A new function fnmatch.filter to filter lists of file names was added.
1361
Barry Warsawffd674d2001-05-22 16:00:10 +00001362- calendar.py uses month and day names based on the current locale.
1363
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001364- strop is now *really* obsolete (this was announced before with 1.6),
1365 and issues DeprecationWarning when used (except for the four items
1366 that are still imported into string.py).
1367
Tim Petersa814db52001-05-14 07:05:58 +00001368- Cookie.py now sorts key+value pairs by key in output strings.
1369
1370- pprint.isrecursive(object) didn't correctly identify recursive objects.
1371 Now it does.
1372
Tim Peters95b3f782001-05-14 18:39:41 +00001373- pprint functions now much faster for large containers (tuple, list, dict).
1374
Tim Peters7b9542a2001-06-10 23:40:19 +00001375- New 'q' and 'Q' format codes in the struct module, corresponding to C
1376 types "long long" and "unsigned long long" (on Windows, __int64). In
1377 native mode, these can be used only when the platform C compiler supports
1378 these types (when HAVE_LONG_LONG is #define'd by the Python config
1379 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001380 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1381 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001382
Guido van Rossum83213cc2001-06-12 16:48:52 +00001383- The site module installs a new built-in function 'help' that invokes
1384 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1385 it displays a message reminding the user to use 'help()' or
1386 'help(object)'.
1387
Tim Petersa814db52001-05-14 07:05:58 +00001388Tests
1389
1390- New test_mutants.py runs dict comparisons where the key and value
1391 comparison operators mutute the dicts randomly during comparison. This
1392 rapidly causes Python to crash under earlier releases (not for the faint
1393 of heart: it can also cause Win9x to freeze or reboot!).
1394
1395- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001396 pprint.isreadable() return sensible results. Also verifies that simple
1397 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001398
Tim Peters4324aa32001-05-28 22:30:08 +00001399C API
1400
1401- Removed the unused last_is_sticky argument from the internal
1402 _PyTuple_Resize(). If this affects you, you were cheating.
1403
1404
Guido van Rossum55a78992001-07-17 17:22:32 +00001405======================================================================
1406
1407
Guido van Rossumffe13be2001-04-16 18:46:45 +00001408What's New in Python 2.1 (final)?
1409=================================
1410
1411We only changed a few things since the last release candidate, all in
1412Python library code:
1413
1414- A bug in the locale module was fixed that affected locales which
1415 define no grouping for numeric formatting.
1416
1417- A few bugs in the weakref module's implementations of weak
1418 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1419 and the test suite was updated to check for these bugs.
1420
1421- An old bug in the os.path.walk() function (introduced in Python
1422 2.0!) was fixed: a non-existent file would cause an exception
1423 instead of being ignored.
1424
1425- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1426 PyChecker.
1427
1428
Guido van Rossum5b08f132001-04-16 02:05:23 +00001429What's New in Python 2.1c2?
1430===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001431
Guido van Rossum5b08f132001-04-16 02:05:23 +00001432A flurry of small changes, and one showstopper fixed in the nick of
1433time made it necessary to release another release candidate. The list
1434here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001435
Guido van Rossum5b08f132001-04-16 02:05:23 +00001436Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001437
Guido van Rossum5b08f132001-04-16 02:05:23 +00001438- Tim discovered a nasty bug in the dictionary code, caused by
1439 PyDict_Next() calling dict_resize(), and the GC code's use of
1440 PyDict_Next() violating an assumption in dict_items(). This was
1441 fixed with considerable amounts of band-aid, but the net effect is a
1442 saner and more robust implementation.
1443
1444- Made a bunch of symbols static that were accidentally global.
1445
1446Build and Ports
1447
1448- The setup.py script didn't check for a new enough version of zlib
1449 (1.1.3 is needed). Now it does.
1450
1451- Changed "make clean" target to also remove shared libraries.
1452
1453- Added a more general warning about the SGI Irix optimizer to README.
1454
1455Library
1456
1457- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1458 omitted the slash between host and file.html.
1459
1460- The mailbox module's _Mailbox class contained a completely broken
1461 and undocumented seek() method. Ripped it out.
1462
1463- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1464 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1465
1466- Fixed a few last-minute bugs in unittest.
1467
1468Extensions
1469
1470- Reverted the patch to the OpenSSL code in socketmodule.c to support
1471 RAND_status() and the EGD, and the subsequent patch that tried to
1472 fix it for pre-0.9.5 versions; the problem with the patch is that on
1473 some systems it issues a warning whenever socket is imported, and
1474 that's unacceptable.
1475
1476Tests
1477
1478- Fixed the pickle tests to work with "import test.test_pickle".
1479
1480- Tweaked test_locale.py to actually run the test Windows.
1481
1482- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1483 not "wb" (which is not a valid mode at all).
1484
1485- Fix pstats browser crashes. Import readline if it exists to make
1486 the user interface nicer.
1487
1488- Add "import thread" to the top of test modules that import the
1489 threading module (test_asynchat and test_threadedtempfile). This
1490 prevents test failures caused by a broken threading module resulting
1491 from a previously caught failed import.
1492
1493- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1494 needed on some platforms (e.g. Solaris 8) when the tests are run
1495 twice in succession.
1496
1497- Skip rather than fail test_sunaudiodev if no audio device is found.
1498
1499
1500What's New in Python 2.1c1?
1501===========================
1502
1503This list was significantly updated when 2.1c2 was released; the 2.1c1
1504release didn't mention most changes that were actually part of 2.1c1:
1505
1506Legal
1507
1508- Copyright was assigned to the Python Software Foundation (PSF) and a
1509 PSF license (very similar to the CNRI license) was added.
1510
1511- The CNRI copyright notice was updated to include 2001.
1512
1513Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001514
Guido van Rossumc9932722001-04-12 02:31:27 +00001515- After a public outcry, assignment to __debug__ is no longer illegal;
1516 instead, a warning is issued. It will become illegal in 2.2.
1517
Guido van Rossum5b08f132001-04-16 02:05:23 +00001518- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1519 "%#x" now always prepends "0x", even if the value is zero.
1520
1521- Fixed some nits in the bytecode compiler.
1522
1523- Fixed core dumps when calling certain kinds of non-functions.
1524
1525- Fixed various core dumps caused by reference count bugs.
1526
1527Build and Ports
1528
1529- Use INSTALL_SCRIPT to install script files.
1530
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001531- New port: SCO Unixware 7, by Billy G. Allie.
1532
Guido van Rossum5b08f132001-04-16 02:05:23 +00001533- Updated RISCOS port.
1534
1535- Updated BeOS port and notes.
1536
1537- Various other porting problems resolved.
1538
1539Library
1540
1541- The TERMIOS and SOCKET modules are now truly obsolete and
1542 unnecessary. Their symbols are incorporated in the termios and
1543 socket modules.
1544
1545- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1546 better tests for pickling.
1547
1548- threading: make Condition.wait() robust against KeyboardInterrupt.
1549
1550- zipfile: add support to zipfile to support opening an archive
1551 represented by an open file rather than a file name. Fix bug where
1552 the archive was not properly closed. Fixed a bug in this bugfix
1553 where flush() was called for a read-only file.
1554
1555- imputil: added an uninstall() method to the ImportManager.
1556
1557- Canvas: fixed bugs in lower() and tkraise() methods.
1558
1559- SocketServer: API change (added overridable close_request() method)
1560 so that the TCP server can explicitly close the request.
1561
1562- pstats: Eric Raymond added a simple interactive statistics browser,
1563 invoked when the module is run as a script.
1564
1565- locale: fixed a problem in format().
1566
1567- webbrowser: made it work when the BROWSER environment variable has a
1568 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1569 KDE 2. Fixed some other nits.
1570
1571- unittest: changes to allow using a different exception than
1572 AssertionError, and added a few more function aliases. Some other
1573 small changes.
1574
1575- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1576
1577- asynchat: fixed a critical bug in asynchat that slipped through the
1578 2.1b2 release. Fixed another rare bug.
1579
1580- Fix some unqualified except: clauses (always a bad code example).
1581
1582XML
1583
1584- pyexpat: new API get_version_string().
1585
1586- Fixed some minidom bugs.
1587
1588Extensions
1589
1590- Fixed a core dump in _weakref. Removed the weakref.mapping()
1591 function (it adds nothing to the API).
1592
1593- Rationalized the use of header files in the readline module, to make
1594 it compile (albeit with some warnings) with the very recent readline
1595 4.2, without breaking for earlier versions.
1596
1597- Hopefully fixed a buffering problem in linuxaudiodev.
1598
1599- Attempted a fix to make the OpenSSL support in the socket module
1600 work again with pre-0.9.5 versions of OpenSSL.
1601
1602Tests
1603
1604- Added a test case for asynchat and asyncore.
1605
1606- Removed coupling between tests where one test failing could break
1607 another.
1608
1609Tools
1610
1611- Ping added an interactive help browser to pydoc, fixed some nits
1612 in the rest of the pydoc code, and added some features to his
1613 inspect module.
1614
1615- An updated python-mode.el version 4.1 which integrates Ken
1616 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1617 much nicer in XEmacs and Emacs. When stepping through your program
1618 with pdb, in either the shell window or the *Python* window, the
1619 source file and line will be tracked by an arrow. Very cool!
1620
1621- IDLE: syntax warnings in interactive mode are changed into errors.
1622
1623- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001624 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001625
1626- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001627
Barry Warsaw11e89c72001-04-11 20:37:57 +00001628
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001629What's New in Python 2.1 beta 2?
1630================================
1631
Guido van Rossum053ae352001-03-22 14:17:21 +00001632(Unlisted are many fixed bugs, more documentation, etc.)
1633
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001634Core language, builtins, and interpreter
1635
Guido van Rossum053ae352001-03-22 14:17:21 +00001636- The nested scopes work (enabled by "from __future__ import
1637 nested_scopes") is completed; in particular, the future now extends
1638 into code executed through exec, eval() and execfile(), and into the
1639 interactive interpreter.
1640
1641- When calling a base class method (e.g. BaseClass.__init__(self)),
1642 this is now allowed even if self is not strictly spoken a class
1643 instance (e.g. when using metaclasses or the Don Beaudry hook).
1644
1645- Slice objects are now comparable but not hashable; this prevents
1646 dict[:] from being accepted but meaningless.
1647
1648- Complex division is now calculated using less braindead algorithms.
1649 This doesn't change semantics except it's more likely to give useful
1650 results in extreme cases. Complex repr() now uses full precision
1651 like float repr().
1652
1653- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1654
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001655- It is illegal to assign to the name __debug__, which is set when the
1656 interpreter starts. It is effectively a compile-time constant.
1657
1658- A warning will be issued if a global statement for a variable
1659 follows a use or assignment of that variable.
1660
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001661Standard library
1662
Guido van Rossum053ae352001-03-22 14:17:21 +00001663- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1664 inspired by JUnit), is now part of the standard library. You now
1665 have a choice of two testing frameworks: unittest requires you to
1666 write testcases as separate code, doctest gathers them from
1667 docstrings. Both approaches have their advantages and
1668 disadvantages.
1669
1670- A new module Tix was added, which wraps the Tix extension library
1671 for Tk. With that module, it is not necessary to statically link
1672 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1673 require" command. See Demo/tix/.
1674
1675- tzparse.py is now obsolete.
1676
1677- In gzip.py, the seek() and tell() methods are removed -- they were
1678 non-functional anyway, and it's better if callers can test for their
1679 existence with hasattr().
1680
1681Python/C API
1682
1683- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1684 that's already in the dictionary during a PyDict_Next() iteration.
1685 This used to fail occasionally when a dictionary resize operation
1686 could be triggered that would rehash all the keys. All other
1687 modifications to the dictionary are still off-limits during a
1688 PyDict_Next() iteration!
1689
1690- New extended APIs related to passing compiler variables around.
1691
1692- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1693 implement isinstance() and issubclass().
1694
1695- Py_BuildValue() now has a "D" conversion to create a Python complex
1696 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001697
Fred Drake4e262a92001-03-22 18:26:47 +00001698- Extensions types which support weak references must now set the
1699 field allocated for the weak reference machinery to NULL themselves;
1700 this is done to avoid the cost of checking each object for having a
1701 weakly referencable type in PyObject_INIT(), since most types are
1702 not weakly referencable.
1703
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001704- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1705 free variables and cell variables to and from the frame's f_locals.
1706
1707- Variants of several functions defined in pythonrun.h have been added
1708 to support the nested_scopes future statement. The variants all end
1709 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1710 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1711 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001712 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001713
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001714Distutils
1715
1716- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1717 into the release tree.
1718
Tim Peters0e57abf2001-05-02 07:39:38 +00001719- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001720 (an uninstaller, more customization of the installer's display)
1721
1722- from Jack Jansen: added Mac-specific code to generate a dialog for
1723 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001724 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001725 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001726
1727- added 'platforms' and 'keywords' to the set of metadata that can be
1728 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001729
1730- applied patches from Jason Tishler to make the compiler class work with
1731 Cygwin.
1732
1733
Tim Peters2fe289a2001-03-01 22:19:38 +00001734What's New in Python 2.1 beta 1?
1735================================
Tim Petersd66595f2001-02-04 03:09:53 +00001736
1737Core language, builtins, and interpreter
1738
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001739- Following an outcry from the community about the amount of code
1740 broken by the nested scopes feature introduced in 2.1a2, we decided
1741 to make this feature optional, and to wait until Python 2.2 (or at
1742 least 6 months) to make it standard. The option can be enabled on a
1743 per-module basis by adding "from __future__ import nested_scopes" at
1744 the beginning of a module (before any other statements, but after
1745 comments and an optional docstring). See PEP 236 (Back to the
1746 __future__) for a description of the __future__ statement. PEP 227
1747 (Statically Nested Scopes) has been updated to reflect this change,
1748 and to clarify the semantics in a number of endcases.
1749
1750- The nested scopes code, when enabled, has been hardened, and most
1751 bugs and memory leaks in it have been fixed.
1752
1753- Compile-time warnings are now generated for a number of conditions
1754 that will break or change in meaning when nested scopes are enabled:
1755
1756 - Using "from...import *" or "exec" without in-clause in a function
1757 scope that also defines a lambda or nested function with one or
1758 more free (non-local) variables. The presence of the import* or
1759 bare exec makes it impossible for the compiler to determine the
1760 exact set of local variables in the outer scope, which makes it
1761 impossible to determine the bindings for free variables in the
1762 inner scope. To avoid the warning about import *, change it into
1763 an import of explicitly name object, or move the import* statement
1764 to the global scope; to avoid the warning about bare exec, use
1765 exec...in... (a good idea anyway -- there's a possibility that
1766 bare exec will be deprecated in the future).
1767
1768 - Use of a global variable in a nested scope with the same name as a
1769 local variable in a surrounding scope. This will change in
1770 meaning with nested scopes: the name in the inner scope will
1771 reference the variable in the outer scope rather than the global
1772 of the same name. To avoid the warning, either rename the outer
1773 variable, or use a global statement in the inner function.
1774
Neil Schemenauera35c6882001-02-27 04:45:05 +00001775- An optional object allocator has been included. This allocator is
1776 optimized for Python objects and should be faster and use less memory
1777 than the standard system allocator. It is not enabled by default
1778 because of possible thread safety problems. The allocator is only
1779 protected by the Python interpreter lock and it is possible that some
1780 extension modules require a thread safe allocator. The object
1781 allocator can be enabled by providing the "--with-pymalloc" option to
1782 configure.
1783
Tim Petersd66595f2001-02-04 03:09:53 +00001784Standard library
1785
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001786- pyexpat now detects the expat version if expat.h defines it. A
1787 number of additional handlers are provided, which are only available
1788 since expat 1.95. In addition, the methods SetParamEntityParsing and
1789 GetInputContext of Parser objects are available with 1.95.x
1790 only. Parser objects now provide the ordered_attributes and
1791 specified_attributes attributes. A new module expat.model was added,
1792 which offers a number of additional constants if 1.95.x is used.
1793
1794- xml.dom offers the new functions registerDOMImplementation and
1795 getDOMImplementation.
1796
1797- xml.dom.minidom offers a toprettyxml method. A number of DOM
1798 conformance issues have been resolved. In particular, Element now
1799 has an hasAttributes method, and the handling of namespaces was
1800 improved.
1801
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001802- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1803 getting information about live Python code, and pydoc.py, a module
1804 for interactively converting docstrings to HTML or text.
1805 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001806 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001807 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1808 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001809
Tim Peters1eff7962001-03-01 02:31:33 +00001810- New library module difflib.py, primarily packaging the SequenceMatcher
1811 class at the heart of the popular ndiff.py file-comparison tool.
1812
1813- doctest.py (a framework for verifying Python code examples in docstrings)
1814 is now part of the std library.
1815
Tim Petersd66595f2001-02-04 03:09:53 +00001816Windows changes
1817
Guido van Rossume3955a82001-03-02 14:05:59 +00001818- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1819 small GUI that lets you browse the module docstrings using your
1820 default web browser.
1821
Tim Peters1eff7962001-03-01 02:31:33 +00001822- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1823 Platforms) is implemented. See
1824
1825 http://python.sourceforge.net/peps/pep-0235.html
1826
1827 for full details, especially the "Current Lower-Left Semantics" section.
1828 The new Windows import rules are simpler than before:
1829
1830 A. If the PYTHONCASEOK environment variable exists, same as
1831 before: silently accept the first case-insensitive match of any
1832 kind; raise ImportError if none found.
1833
1834 B. Else search sys.path for the first case-sensitive match; raise
1835 ImportError if none found.
1836
1837 The same rules have been implented on other platforms with case-
1838 insensitive but case-preserving filesystems too (including Cygwin, and
1839 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001840
Tim Peters25a9ce32001-02-19 07:06:36 +00001841- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1842 what it's supposed to do (and does do under NT and 2000) via direct
1843 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001844 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001845 all Win9x systems before.
1846
Tim Peters1eff7962001-03-01 02:31:33 +00001847- Build: Subproject _test (effectively) renamed to _testcapi.
1848
Tim Peters2fe289a2001-03-01 22:19:38 +00001849New platforms
1850
1851- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1852 Thanks to Steven Majewski!
1853
1854- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1855 Tishler!
1856
Guido van Rossum9089b272001-03-02 06:49:50 +00001857- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1858 Schwertberger! See RISCOS/README for more information -- it seems
1859 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001860 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001861
Tim Peters25a9ce32001-02-19 07:06:36 +00001862
Tim Petersd7b5e882001-01-25 03:36:26 +00001863What's New in Python 2.1 alpha 2?
1864=================================
Tim Peters40ead762001-01-27 05:35:26 +00001865
Tim Petersd7b5e882001-01-25 03:36:26 +00001866Core language, builtins, and interpreter
1867
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001868- Scopes nest. If a name is used in a function or class, but is not
1869 local, the definition in the nearest enclosing function scope will
1870 be used. One consequence of this change is that lambda statements
1871 could reference variables in the namespaces where the lambda is
1872 defined. In some unusual cases, this change will break code.
1873
1874 In all previous version of Python, names were resolved in exactly
1875 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001876 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001877 function A is defined within a function B, the names bound in B are
1878 not visible in A. The new rules make names bound in B visible in A,
1879 unless A contains a name binding that hides the binding in B.
1880
1881 Section 4.1 of the reference manual describes the new scoping rules
1882 in detail. The test script in Lib/test/test_scope.py demonstrates
1883 some of the effects of the change.
1884
1885 The new rules will cause existing code to break if it defines nested
1886 functions where an outer function has local variables with the same
1887 name as globals or builtins used by the inner function. Example:
1888
1889 def munge(str):
1890 def helper(x):
1891 return str(x)
1892 if type(str) != type(''):
1893 str = helper(str)
1894 return str.strip()
1895
1896 Under the old rules, the name str in helper() is bound to the
1897 builtin function str(). Under the new rules, it will be bound to
1898 the argument named str and an error will occur when helper() is
1899 called.
1900
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001901- The compiler will report a SyntaxError if "from ... import *" occurs
1902 in a function or class scope. The language reference has documented
1903 that this case is illegal, but the compiler never checked for it.
1904 The recent introduction of nested scope makes the meaning of this
1905 form of name binding ambiguous. In a future release, the compiler
1906 may allow this form when there is no possibility of ambiguity.
1907
Tim Peters40ead762001-01-27 05:35:26 +00001908- repr(string) is easier to read, now using hex escapes instead of octal,
1909 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1910
1911 >>> "\texample \r\n" + chr(0) + chr(255)
1912 '\texample \r\n\x00\xff' # in 2.1
1913 '\011example \015\012\000\377' # in 2.0
1914
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001915- Functions are now compared and hashed by identity, not by value, since
1916 the func_code attribute is writable.
1917
Fred Drakefb9d7122001-02-01 20:00:40 +00001918- Weak references (PEP 205) have been added. This involves a few
1919 changes in the core, an extension module (_weakref), and a Python
1920 module (weakref). The weakref module is the public interface. It
1921 includes support for "explicit" weak references, proxy objects, and
1922 mappings with weakly held values.
1923
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001924- A 'continue' statement can now appear in a try block within the body
1925 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001926 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001927
Tim Petersd7b5e882001-01-25 03:36:26 +00001928Standard library
1929
Barry Warsaw30dbd142001-01-31 22:14:01 +00001930- mailbox.py now has a new class, PortableUnixMailbox which is
1931 identical to UnixMailbox but uses a more portable scheme for
1932 determining From_ separators. Also, the constructors for all the
1933 classes in this module have a new optional `factory' argument, which
1934 is a callable used when new message classes must be instantiated by
1935 the next() method.
1936
Tim Petersd7b5e882001-01-25 03:36:26 +00001937- random.py is now self-contained, and offers all the functionality of
1938 the now-deprecated whrandom.py. See the docs for details. random.py
1939 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001940 and restoring the internal state of the generator; and jumpahead(n),
1941 for quickly forcing the internal state to be the same as if n calls to
1942 random() had been made. The latter is particularly useful for multi-
1943 threaded programs, creating one instance of the random.Random() class for
1944 each thread, then using .jumpahead() to force each instance to use a
1945 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001946
Tim Peters0de88fc2001-02-01 04:59:18 +00001947- random.py's seed() function is new. For bit-for-bit compatibility with
1948 prior releases, use the whseed function instead. The new seed function
1949 addresses two problems: (1) The old function couldn't produce more than
1950 about 2**24 distinct internal states; the new one about 2**45 (the best
1951 that can be done in the Wichmann-Hill generator). (2) The old function
1952 sometimes produced identical internal states when passed distinct
1953 integers, and there was no simple way to predict when that would happen;
1954 the new one guarantees to produce distinct internal states for all
1955 arguments in [0, 27814431486576L).
1956
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001957- The socket module now supports raw packets on Linux. The socket
1958 family is AF_PACKET.
1959
Tim Peters9ea17ac2001-02-02 05:57:15 +00001960- test_capi.py is a start at running tests of the Python C API. The tests
1961 are implemented by the new Modules/_testmodule.c.
1962
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001963- A new extension module, _symtable, provides provisional access to the
1964 internal symbol table used by the Python compiler. A higher-level
1965 interface will be added on top of _symtable in a future release.
1966
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001967- Removed the obsolete soundex module.
1968
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001969- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1970 the isSameNode method; NamedNodeMap the get method.
1971
1972- xml.sax.expatreader supports the lexical handler property; it
1973 generates comment, startCDATA, and endCDATA events.
1974
Tim Petersee826f82001-01-31 19:39:44 +00001975Windows changes
1976
1977- Build procedure: the zlib project is built in a different way that
1978 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001979 the zlib binary used. See PCbuild\readme.txt for details. Your old
1980 zlib-related directories can be deleted; you'll need to download fresh
1981 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001982
Tim Peters9ea17ac2001-02-02 05:57:15 +00001983- Build: New subproject _test for the benefit of test_capi.py (see above).
1984
Tim Petersb16c56f2001-02-02 21:24:51 +00001985- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1986 interface to some Python compiler internals).
1987
1988- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001989 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001990
Tim Petersa3a3a032000-11-30 05:22:44 +00001991What's New in Python 2.1 alpha 1?
1992=================================
1993
1994Core language, builtins, and interpreter
1995
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001996- There is a new Unicode companion to the PyObject_Str() API
1997 called PyObject_Unicode(). It behaves in the same way as the
1998 former, but assures that the returned value is an Unicode object
1999 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002000
Guido van Rossumf98eda02001-01-17 15:54:45 +00002001- The comparison operators support "rich comparison overloading" (PEP
2002 207). C extension types can provide a rich comparison function in
2003 the new tp_richcompare slot in the type object. The cmp() function
2004 and the C function PyObject_Compare() first try the new rich
2005 comparison operators before trying the old 3-way comparison. There
2006 is also a new C API PyObject_RichCompare() (which also falls back on
2007 the old 3-way comparison, but does not constrain the outcome of the
2008 rich comparison to a Boolean result).
2009
2010 The rich comparison function takes two objects (at least one of
2011 which is guaranteed to have the type that provided the function) and
2012 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2013 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2014 object, which may be NotImplemented (in which case the tp_compare
2015 slot function is used as a fallback, if defined).
2016
2017 Classes can overload individual comparison operators by defining one
2018 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002019 __ge__. There are no explicit "reflected argument" versions of
2020 these; instead, __lt__ and __gt__ are each other's reflection,
2021 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2022 reflection (similar at the C level). No other implications are
2023 made; in particular, Python does not assume that == is the Boolean
2024 inverse of !=, or that < is the Boolean inverse of >=. This makes
2025 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002026
2027 Classes or types that want to implement (in)equality tests but not
2028 the ordering operators (i.e. unordered types) should implement ==
2029 and !=, and raise an error for the ordering operators.
2030
Guido van Rossuma88479f2001-01-18 14:28:08 +00002031 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002032 Boolean; e.g. a matrix type might want to return a matrix of bits
2033 for A < B, giving elementwise comparisons. Such types should ensure
2034 that any interpretation of their value in a Boolean context raises
2035 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2036 at the C level) to always raise an exception.
2037
Guido van Rossuma88479f2001-01-18 14:28:08 +00002038- Complex numbers use rich comparisons to define == and != but raise
2039 an exception for <, <=, > and >=. Unfortunately, this also means
2040 that cmp() of two complex numbers raises an exception when the two
2041 numbers differ. Since it is not mathematically meaningful to compare
2042 complex numbers except for equality, I hope that this doesn't break
2043 too much code.
2044
Tim Peters3389f192001-02-18 08:48:49 +00002045- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002046 not defined by the language, other than that it's arbitrary but
2047 consistent (see the Reference Manual). An implementation detail changed
2048 in 2.1a1 such that None now compares less than any other object. Code
2049 relying on this new behavior (like code that relied on the previous
2050 behavior) does so at its own risk.
2051
Barry Warsaw573b5412001-01-15 20:43:18 +00002052- Functions and methods now support getting and setting arbitrarily
2053 named attributes (PEP 232). Functions have a new __dict__
2054 (a.k.a. func_dict) which hold the function attributes. Methods get
2055 and set attributes on their underlying im_func. It is a TypeError
2056 to set an attribute on a bound method.
2057
Guido van Rossum051e3352001-01-15 19:11:10 +00002058- The xrange() object implementation has been improved so that
2059 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2060 limitation that in this case len(xrange(sys.maxint)) can't be
2061 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2062 work fine as long as the index i doesn't actually reach 2**31.
2063 (Python uses regular ints for sequence and string indices; fixing
2064 that is much more work.)
2065
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002066- Two changes to from...import:
2067
Guido van Rossumba381232001-02-03 15:06:40 +00002068 1) "from M import X" now works even if (after loading module M)
2069 sys.modules['M'] is not a real module; it's basically a getattr()
2070 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002071
2072 2) "from M import *" now looks for M.__all__ to decide which names to
2073 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2074 filters out names starting with '_' as before. Whether or not
2075 __all__ exists, there's no restriction on the type of M.
2076
Guido van Rossumf61f1662001-01-10 20:13:55 +00002077- File objects have a new method, xreadlines(). This is the fastest
2078 way to iterate over all lines in a file:
2079
2080 for line in file.xreadlines():
2081 ...do something to line...
2082
2083 See the xreadlines module (mentioned below) for how to do this for
2084 other file-like objects.
2085
2086- Even if you don't use file.xreadlines(), you may expect a speedup on
2087 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002088 quite a bit in platform-specific ways: on systems (like Linux) that
2089 support flockfile(), getc_unlocked(), and funlockfile(), those are
2090 used by default. On systems (like Windows) without getc_unlocked(),
2091 a complicated (but still thread-safe) method using fgets() is used by
2092 default.
2093
Tim Petersd52269b2001-01-25 06:23:18 +00002094 You can force use of the fgets() method by #define'ing
2095 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002096 getc_unlocked()).
2097
Tim Petersd52269b2001-01-25 06:23:18 +00002098 You can force fgets() not to be used by #define'ing
2099 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002100 test_bufio.py fails -- and let us know if it does!).
2101
2102- In addition, the fileinput module, while still slower than the other
2103 methods on most platforms, has been sped up too, by using
2104 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002105
2106- Support for run-time warnings has been added, including a new
2107 command line option (-W) to specify the disposition of warnings.
2108 See the description of the warnings module below.
2109
2110- Extensive changes have been made to the coercion code. This mostly
2111 affects extension modules (which can now implement mixed-type
2112 numerical operators without having to use coercion), but
2113 occasionally, in boundary cases the coercion semantics have changed
2114 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002115 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002116 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002117 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002118
Guido van Rossumf98eda02001-01-17 15:54:45 +00002119- In connection with the coercion changes, a new built-in singleton
2120 object, NotImplemented is defined. This can be returned for
2121 operations that wish to indicate they are not implemented for a
2122 particular combination of arguments. From C, this is
2123 Py_NotImplemented.
2124
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002125- The interpreter accepts now bytecode files on the command line even
2126 if they do not have a .pyc or .pyo extension. On Linux, after executing
2127
Martin v. Löwise214baa2001-02-04 22:37:56 +00002128import imp,sys,string
2129magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2130reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2131open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002132
2133 any byte code file can be used as an executable (i.e. as an argument
2134 to execve(2)).
2135
Tim Peters9940b802000-12-01 07:59:35 +00002136- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002137 character. In 1.6 and earlier, they never produced a sign,
2138 and raised an error if the value of the long was too large
2139 to fit in a Python int. In 2.0, they produced a sign if and
2140 only if too large to fit in an int. This was inconsistent
2141 across platforms (because the size of an int varies across
2142 platforms), and inconsistent with hex() and oct(). Example:
2143
2144 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002145 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002146 'ffffffbe' # in 2.0 and before, on 32-bit machines
2147 >>> hex(-0x42L)
2148 '-0x42L' # in all versions of Python
2149
Tim Peters9940b802000-12-01 07:59:35 +00002150 The behavior of %d formats for negative Python longs remains
2151 the same as in 2.0 (although in 1.6 and before, they raised
2152 an error if the long didn't fit in a Python int).
2153
2154 %u formats don't make sense for Python longs, but are allowed
2155 and treated the same as %d in 2.1. In 2.0, a negative long
2156 formatted via %u produced a sign if and only if too large to
2157 fit in an int. In 1.6 and earlier, a negative long formatted
2158 via %u raised an error if it was too big to fit in an int.
2159
Guido van Rossum3661d392000-12-12 22:10:31 +00002160- Dictionary objects have an odd new method, popitem(). This removes
2161 an arbitrary item from the dictionary and returns it (in the form of
2162 a (key, value) pair). This can be useful for algorithms that use a
2163 dictionary as a bag of "to do" items and repeatedly need to pick one
2164 item. Such algorithms normally end up running in quadratic time;
2165 using popitem() they can usually be made to run in linear time.
2166
Tim Peters36cdad12000-12-29 02:06:45 +00002167Standard library
2168
Thomas Woutersfe385252001-01-19 23:16:56 +00002169- In the time module, the time argument to the functions strftime,
2170 localtime, gmtime, asctime and ctime is now optional, defaulting to
2171 the current time (in the local timezone).
2172
Guido van Rossumda91f222001-01-15 16:36:08 +00002173- The ftplib module now defaults to passive mode, which is deemed a
2174 more useful default given that clients are often inside firewalls
2175 these days. Note that this could break if ftplib is used to connect
2176 to a *server* that is inside a firewall, from outside; this is
2177 expected to be a very rare situation. To fix that, you can call
2178 ftp.set_pasv(0).
2179
Martin v. Löwis10a27872001-01-13 09:54:41 +00002180- The module site now treats .pth files not only for path configuration,
2181 but also supports extensions to the initialization code: Lines starting
2182 with import are executed.
2183
Guido van Rossumf61f1662001-01-10 20:13:55 +00002184- There's a new module, warnings, which implements a mechanism for
2185 issuing and filtering warnings. There are some new built-in
2186 exceptions that serve as warning categories, and a new command line
2187 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2188 turns warnings into errors). warnings.warn(message[, category])
2189 issues a warning message; this can also be called from C as
2190 PyErr_Warn(category, message).
2191
2192- A new module xreadlines was added. This exports a single factory
2193 function, xreadlines(). The intention is that this code is the
2194 absolutely fastest way to iterate over all lines in an open
2195 file(-like) object:
2196
2197 import xreadlines
2198 for line in xreadlines.xreadlines(file):
2199 ...do something to line...
2200
2201 This is equivalent to the previous the speed record holder using
2202 file.readlines(sizehint). Note that if file is a real file object
2203 (as opposed to a file-like object), this is equivalent:
2204
2205 for line in file.xreadlines():
2206 ...do something to line...
2207
Tim Peters36cdad12000-12-29 02:06:45 +00002208- The bisect module has new functions bisect_left, insort_left,
2209 bisect_right and insort_right. The old names bisect and insort
2210 are now aliases for bisect_right and insort_right. XXX_right
2211 and XXX_left methods differ in what happens when the new element
2212 compares equal to one or more elements already in the list: the
2213 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002214 right. Code that doesn't care where equal elements end up should
2215 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002216
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002217- The new curses.panel module wraps the panel library that forms part
2218 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2219
Guido van Rossumf61f1662001-01-10 20:13:55 +00002220- The SocketServer module now sets the allow_reuse_address flag by
2221 default in the TCPServer class.
2222
2223- A new function, sys._getframe(), returns the stack frame pointer of
2224 the caller. This is intended only as a building block for
2225 higher-level mechanisms such as string interpolation.
2226
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002227- The pyexpat module supports a number of new handlers, which are
2228 available only in expat 1.2. If invocation of a callback fails, it
2229 will report an additional frame in the traceback. Parser objects
2230 participate now in garbage collection. If expat reports an unknown
2231 encoding, pyexpat will try to use a Python codec; that works only
2232 for single-byte charsets. The parser type objects is exposed as
2233 XMLParserObject.
2234
2235- xml.dom now offers standard definitions for symbolic node type and
2236 exception code constants, and a hierarchy of DOM exceptions. minidom
2237 was adjusted to use them.
2238
2239- The conformance of xml.dom.minidom to the DOM specification was
2240 improved. It detects a number of additional error cases; the
2241 previous/next relationship works even when the tree is modified;
2242 Node supports the normalize() method; NamedNodeMap, DocumentType and
2243 DOMImplementation classes were added; Element supports the
2244 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2245 method.
2246
Guido van Rossumf61f1662001-01-10 20:13:55 +00002247Build issues
2248
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002249- For Unix (and Unix-compatible) builds, configuration and building of
2250 extension modules is now greatly automated. Rather than having to
2251 edit the Modules/Setup file to indicate which modules should be
2252 built and where their include files and libraries are, a
2253 distutils-based setup.py script now takes care of building most
2254 extension modules. All extension modules built this way are built
2255 as shared libraries. Only a few modules that must be linked
2256 statically are still listed in the Setup file; you won't need to
2257 edit their configuration.
2258
2259- Python should now build out of the box on Cygwin. If it doesn't,
2260 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002261
2262- Python now always uses its own (renamed) implementation of getopt()
2263 -- there's too much variation among C library getopt()
2264 implementations.
2265
2266- C++ compilers are better supported; the CXX macro is always set to a
2267 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002268
Tim Petersd92dfe02000-12-12 01:18:41 +00002269Windows changes
2270
2271- select module: By default under Windows, a select() call
2272 can specify no more than 64 sockets. Python now boosts
2273 this Microsoft default to 512. If you need even more than
2274 that, see the MS docs (you'll need to #define FD_SETSIZE
2275 and recompile Python from source).
2276
Guido van Rossumf61f1662001-01-10 20:13:55 +00002277- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2278 subdirectory is no more!
2279
Tim Petersa3a3a032000-11-30 05:22:44 +00002280
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002281What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002282=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002283
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002284Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002285changes are in the file HISTORY. If you are making the jump directly
2286from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2287HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002288
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002289Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2290the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2291http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002292
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002293--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002294
2295======================================================================
2296
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002297What's new in 2.0 (since release candidate 1)?
2298==============================================
2299
2300Standard library
2301
2302- The copy_reg module was modified to clarify its intended use: to
2303 register pickle support for extension types, not for classes.
2304 pickle() will raise a TypeError if it is passed a class.
2305
2306- Fixed a bug in gettext's "normalize and expand" code that prevented
2307 it from finding an existing .mo file.
2308
2309- Restored support for HTTP/0.9 servers in httplib.
2310
Tim Peters989b7b92000-10-16 20:24:53 +00002311- The math module was changed to stop raising OverflowError in case of
2312 underflow, and return 0 instead in underflow cases. Whether Python
2313 used to raise OverflowError in case of underflow was platform-
2314 dependent (it did when the platform math library set errno to ERANGE
2315 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002316
2317- Fixed a bug in StringIO that occurred when the file position was not
2318 at the end of the file and write() was called with enough data to
2319 extend past the end of the file.
2320
2321- Fixed a bug that caused Tkinter error messages to get lost on
2322 Windows. The bug was fixed by replacing direct use of
2323 interp->result with Tcl_GetStringResult(interp).
2324
2325- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2326 redirect response.
2327
2328- Several changes were made to distutils: Some debugging code was
2329 removed from util. Fixed the installer used when an external zip
2330 program (like WinZip) is not found; the source code for this
2331 installer is in Misc/distutils. check_lib() was modified to behave
2332 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2333 test for whether installed modules are on sys.path was changed to
2334 use both normcase() and normpath().
2335
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002336- Several minor bugs were fixed in the xml package (the minidom,
2337 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002338
2339- The regression test driver (regrtest.py) behavior when invoked with
2340 -l changed: It now reports a count of objects that are recognized as
2341 garbage but not freed by the garbage collector.
2342
Tim Peters989b7b92000-10-16 20:24:53 +00002343- The regression test for the math module was changed to test
2344 exceptional behavior when the test is run in verbose mode. Python
2345 cannot yet guarantee consistent exception behavior across platforms,
2346 so the exception part of test_math is run only in verbose mode, and
2347 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002348
2349Internals
2350
2351- PyOS_CheckStack() has been disabled on Win64, where it caused
2352 test_sre to fail.
2353
2354Build issues
2355
2356- Changed compiler flags, so that gcc is always invoked with -Wall and
2357 -Wstrict-prototypes. Users compiling Python with GCC should see
2358 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002359 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002360 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002361
Tim Petersa3a3a032000-11-30 05:22:44 +00002362- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002363
2364Tools and other miscellany
2365
2366- The compiler in Tools/compiler was updated to support the new
2367 language features introduced in 2.0: extended print statement, list
2368 comprehensions, and augmented assignments. The new compiler should
2369 also be backwards compatible with Python 1.5.2; the compiler will
2370 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002371 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002372
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002373What's new in 2.0 release candidate 1 (since beta 2)?
2374=====================================================
2375
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002376What is release candidate 1?
2377
2378We believe that release candidate 1 will fix all known bugs that we
2379intend to fix for the 2.0 final release. This release should be a bit
2380more stable than the previous betas. We would like to see even more
2381widespread testing before the final release, so we are producing this
2382release candidate. The final release will be exactly the same unless
2383any show-stopping (or brown bag) bugs are found by testers of the
2384release candidate.
2385
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002386All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002387to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002388
2389Core language, builtins, and interpreter
2390
2391- A bug that caused crashes when __coerce__ was used with augmented
2392 assignment, e.g. +=, was fixed.
2393
2394- Raise ZeroDivisionError when raising zero to a negative number,
2395 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2396 power operator and the result of math.pow(0.0, -2.0) will vary by
2397 platform. On Linux, it raises a ValueError.
2398
2399- A bug in Unicode string interpolation was fixed that occasionally
2400 caused errors with formats including "%%". For example, the
2401 following expression "%% %s" % u"abc" no longer raises a TypeError.
2402
2403- Compilation of deeply nested expressions raises MemoryError instead
2404 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2405
2406- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2407 rendering them useless. They are now written in binary mode again.
2408
2409Standard library
2410
2411- Keyword arguments are now accepted for most pattern and match object
2412 methods in SRE, the standard regular expression engine.
2413
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002414- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002415 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002416
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002417- Several bugs in the Unicode handling and error handling in _tkinter
2418 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002419
2420- Fix memory management errors in Merge() and Tkapp_Call() routines.
2421
2422- Several changes were made to cStringIO to make it compatible with
2423 the file-like object interface and with StringIO. If operations are
2424 performed on a closed object, an exception is raised. The truncate
2425 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002426 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002427
2428- There were many changes made to the linuxaudiodev module and its
2429 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002430 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002431
2432 Note that this module is named poorly, because it should work
2433 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002434 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002435
2436 The module now raises exceptions when errors occur instead of
2437 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2438 audio) and defines a getptr() method that calls the
2439 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2440
2441- The library_version attribute, introduced in an earlier beta, was
2442 removed because it can not be supported with early versions of the C
2443 readline library, which provides no way to determine the version at
2444 compile-time.
2445
2446- The binascii module is now enabled on Win64.
2447
Tim Peters46446d62000-10-09 21:19:31 +00002448- tokenize.py no longer suffers "recursion depth" errors when parsing
2449 programs with very long string literals.
2450
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002451Internals
2452
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002453- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002454 which is called when the interpreter starts up to determine where
2455 the standard library is installed. These vulnerabilities affect all
2456 previous versions of Python and can be exploited by setting very
2457 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2458 setuid Python script, although use of the wrapper in
2459 Misc/setuid-prog.c will eliminate the vulnerability.
2460
2461- Fixed garbage collection bugs in instance creation that were
2462 triggered when errors occurred during initialization. The solution,
2463 applied in cPickle and in PyInstance_New(), is to call
2464 PyObject_GC_Init() after the initialization of the object's
2465 container attributes is complete.
2466
2467- pyexpat adds definitions of PyModule_AddStringConstant and
2468 PyModule_AddObject if the Python version is less than 2.0, which
2469 provides compatibility with PyXML on Python 1.5.2.
2470
2471- If the platform has a bogus definition for LONG_BIT (the number of
2472 bits in a long), an error will be reported at compile time.
2473
2474- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2475 collection crashes and possibly other, unreported crashes.
2476
2477- Fixed a memory leak in _PyUnicode_Fini().
2478
2479Build issues
2480
2481- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002482 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002483 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002484
2485- The mmap.PAGESIZE constant is now initialized using sysconf when
2486 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2487
2488- The md5 file should now compile on all platforms.
2489
2490- The select module now compiles on platforms that do not define
2491 POLLRDNORM and related constants.
2492
2493- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002494 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002495
Jeremy Hylton10921202000-10-09 18:34:12 +00002496- BeOS: A number of changes were made to the build and installation
2497 process. ar-fake now operates on a directory of object files.
2498 dl_export.h is gone, and its macros now appear on the mwcc command
2499 line during build on PPC BeOS.
2500
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002501- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002502 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002503
2504- Cygwin: Support for shared libraries, Tkinter, and sockets.
2505
2506- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2507
2508Tools and other miscellany
2509
2510- Removed debugging prints from main used with freeze.
2511
Tim Peters46446d62000-10-09 21:19:31 +00002512- IDLE auto-indent no longer crashes when it encounters Unicode
2513 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002514
2515What's new in 2.0 beta 2 (since beta 1)?
2516========================================
2517
2518Core language, builtins, and interpreter
2519
Tim Peters482c0212000-09-26 06:33:09 +00002520- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002521 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002522
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002523- Add -h and -V command line options to print the usage message and
2524 Python version number and exit immediately.
2525
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002526- eval() and exec accept Unicode objects as code parameters.
2527
2528- getattr() and setattr() now also accept Unicode objects for the
2529 attribute name, which are converted to strings using the default
2530 encoding before lookup.
2531
2532- Multiplication on string and Unicode now does proper bounds
2533 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2534 string is too long."
2535
2536- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002537 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002538
Jeremy Hylton1b618592000-09-26 05:32:36 +00002539
2540Standard library and extensions
2541
Guido van Rossum5b08f132001-04-16 02:05:23 +00002542- socket module: the OpenSSL code now adds support for RAND_status()
2543 and EGD (Entropy Gathering Device).
2544
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002545- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002546 argument checking; it still takes no arguments.
2547
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002548- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002549
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002550- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002551
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002552- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002553
2554- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002555 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002556
2557- copy: Copy Unicode objects atomically.
2558
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002559- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002560
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002561- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002562
Fred Drake67233bc2000-09-26 16:40:27 +00002563- dbm: Add get() and setdefault() methods to dbm object. Add constant
2564 `library' to module that names the library used. Added doc strings
2565 and method names to error messages. Uses configure to determine
2566 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2567 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002568
2569- distutils: Update to version 0.9.3.
2570
2571- dl: Add several dl.RTLD_ constants.
2572
2573- fpectl: Now supported on FreeBSD.
2574
2575- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2576 found by the collector will be saved in gc.garbage. This is useful
2577 for debugging a program that creates reference cycles.
2578
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002579- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002580 of HTTP class. Do not close socket on zero-length response. Do not
2581 crash when server sends invalid content-length header.
2582
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002583- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002584
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002585- marshal: When reading a short, sign-extend on platforms where shorts
2586 are bigger than 16 bits. When reading a long, repair the unportable
2587 sign extension that was being done for 64-bit machines. (It assumed
2588 that signed right shift sign-extends.)
2589
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002590- operator: Add contains(), invert(), __invert__() as aliases for
2591 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002592
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002593- os: Add support for popen2() and popen3() on all platforms where
2594 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002595
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002596- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002597 clicking on a file in Explorer (or passing the file name to the
2598 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002599
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002600- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002601 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002602
2603- pickle: Now raises ValueError when an invalid pickle that contains
2604 a non-string repr where a string repr was expected. This behavior
2605 matches cPickle.
2606
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002607- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002608
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002609- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002610
2611- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002612 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002613 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002614
2615- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002616 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002617
2618- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002619 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002620 few cycles during startup since the first call to
2621 setdefaultencoding() will initialize the codec registry and the
2622 encodings package.
2623
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002624- socket: Support for size hint in readlines() method of object returned
2625 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002626
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002627- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002628 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002629 is followed by whitespace.
2630
Tim Petersa3a3a032000-11-30 05:22:44 +00002631- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002632
2633- struct: Check ranges for bytes and shorts.
2634
2635- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002636 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002637
2638- Tkinter: Image objects are now guaranteed to have unique ids. Set
2639 event.delta to zero if Tk version doesn't support mousewheel.
2640 Removed some debugging prints.
2641
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002642- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002643
Fred Drake67233bc2000-09-26 16:40:27 +00002644- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002645 which works around a bug in Norton AntiVirus 2000 that leads directly
2646 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002647
2648- xml: New version detection code allows PyXML to override standard
2649 XML package if PyXML version is greater than 0.6.1.
2650
Fred Drake64bb3802000-09-26 16:21:35 +00002651- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2652 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2653 tree only for nodes which are sufficiently interesting to a specific
2654 application. Does not provide the HTML-specific extensions. Still
2655 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002656
Fred Drake64bb3802000-09-26 16:21:35 +00002657- xml.sax: SAX 2 support for Python, including all the handler
2658 interfaces needed to process XML 1.0 compliant XML. Some
2659 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002660
Fred Drake64bb3802000-09-26 16:21:35 +00002661- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2662 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002663
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002664
Jeremy Hylton1b618592000-09-26 05:32:36 +00002665C API
2666
2667- Add three new convenience functions for module initialization --
2668 PyModule_AddObject(), PyModule_AddIntConstant(), and
2669 PyModule_AddStringConstant().
2670
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002671- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002672 removed and add #error to Python.h if NULL isn't defined after
2673 #include of stdio.h.
2674
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002675- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002676 backwards compatibility (at the source level) with old extensions.
2677
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002678- A wrapper API was added for signal() and sigaction(). Instead of
2679 either function, always use PyOS_getsig() to get a signal handler
2680 and PyOS_setsig() to set one. A new convenience typedef
2681 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002682
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002683- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002684 internal data buffer and size of a string object -- or the default
2685 encoded version of a Unicode object.
2686
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002687- PyString_Size() and PyString_AsString() accept Unicode objects.
2688
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002689- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002690 exists). INT_MAX and LONG_MAX will always be defined, even if
2691 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002692
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002693- PyFloat_FromString takes a second argument, pend, that was
2694 effectively useless. It is now officially useless but preserved for
2695 backwards compatibility. If the pend argument is not NULL, *pend is
2696 set to NULL.
2697
2698- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2699 for the attribute name. See note on getattr() above.
2700
2701- A few bug fixes to argument processing for Unicode.
2702 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2703 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2704 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002705 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002706
2707- Py_BuildValue accepts B format (for bgen-generated code).
2708
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002709
Jeremy Hylton1b618592000-09-26 05:32:36 +00002710Internals
2711
2712- On Unix, fix code for finding Python installation directory so that
2713 it works when argv[0] is a relative path.
2714
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002715- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002716 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002717 rather than by generating a copy of the object.
2718
Tim Peters482c0212000-09-26 06:33:09 +00002719- Several of the internal Unicode tables are much smaller now, and
2720 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721
Jeremy Hylton97693b02000-09-26 17:42:51 +00002722- In the garbage collector: Fixed bug in collection of tuples. Fixed
2723 bug that caused some instances to be removed from the container set
2724 while they were still live. Fixed parsing in gc.set_debug() for
2725 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002726
2727- Fixed refcount problem in instance deallocation that only occurred
2728 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2729
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002730- On Windows, getpythonregpath is now protected against null data in
2731 registry key.
2732
2733- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002734 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002735
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002736
Jeremy Hylton1b618592000-09-26 05:32:36 +00002737Build and platform-specific issues
2738
2739- Better support of GNU Pth via --with-pth configure option.
2740
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002741- Python/C API now properly exposed to dynamically-loaded extension
2742 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002743
2744- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2745 Don't define MS_SYNC to be zero when it is undefined. Added missing
2746 prototypes in posixmodule.c.
2747
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002748- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002749 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002750
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002751- Fix largefile support on older NetBSD systems and OpenBSD by adding
2752 define for TELL64.
2753
2754
2755Tools and other miscellany
2756
2757- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2758
2759- freeze: The modulefinder now works with 2.0 opcodes.
2760
Tim Petersa3a3a032000-11-30 05:22:44 +00002761- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002762 Move hackery of sys.argv until after the Tk instance has been
2763 created, which allows the application-specific Tkinter
2764 initialization to be executed if present; also pass an explicit
2765 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002766
Jeremy Hylton1b618592000-09-26 05:32:36 +00002767
2768What's new in 2.0 beta 1?
2769=========================
2770
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002771Source Incompatibilities
2772------------------------
2773
2774None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2775such as single-argument append(), connect() and bind(), and changes to
2776str(long) and repr(float).
2777
2778
2779Binary Incompatibilities
2780------------------------
2781
2782- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2783with Python 2.0; these extensions will have to be rebuilt for Python
27842.0.
2785
2786- On Windows, attempting to import a third party extension built for
2787Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2788can do about this. Check your PYTHONPATH environment variable!
2789
2790- Python bytecode files (*.pyc and *.pyo) are not compatible between
2791releases.
2792
2793
2794Overview of Changes Since 1.6
2795-----------------------------
2796
2797There are many new modules (including brand new XML support through
2798the xml package, and i18n support through the gettext module); a list
2799of all new modules is included below. Lots of bugs have been fixed.
2800
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002801The process for making major new changes to the language has changed
2802since Python 1.6. Enhancements must now be documented by a Python
2803Enhancement Proposal (PEP) before they can be accepted.
2804
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002805There are several important syntax enhancements, described in more
2806detail below:
2807
2808 - Augmented assignment, e.g. x += 1
2809
2810 - List comprehensions, e.g. [x**2 for x in range(10)]
2811
2812 - Extended import statement, e.g. import Module as Name
2813
2814 - Extended print statement, e.g. print >> file, "Hello"
2815
2816Other important changes:
2817
2818 - Optional collection of cyclical garbage
2819
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002820Python Enhancement Proposal (PEP)
2821---------------------------------
2822
2823PEP stands for Python Enhancement Proposal. A PEP is a design
2824document providing information to the Python community, or describing
2825a new feature for Python. The PEP should provide a concise technical
2826specification of the feature and a rationale for the feature.
2827
2828We intend PEPs to be the primary mechanisms for proposing new
2829features, for collecting community input on an issue, and for
2830documenting the design decisions that have gone into Python. The PEP
2831author is responsible for building consensus within the community and
2832documenting dissenting opinions.
2833
2834The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002835
2836Augmented Assignment
2837--------------------
2838
2839This must have been the most-requested feature of the past years!
2840Eleven new assignment operators were added:
2841
Guido van Rossume905e952000-09-05 12:42:46 +00002842 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002843
2844For example,
2845
2846 A += B
2847
2848is similar to
2849
2850 A = A + B
2851
2852except that A is evaluated only once (relevant when A is something
2853like dict[index].attr).
2854
2855However, if A is a mutable object, A may be modified in place. Thus,
2856if A is a number or a string, A += B has the same effect as A = A+B
2857(except A is only evaluated once); but if a is a list, A += B has the
2858same effect as A.extend(B)!
2859
2860Classes and built-in object types can override the new operators in
2861order to implement the in-place behavior; the not-in-place behavior is
2862used automatically as a fallback when an object doesn't implement the
2863in-place behavior. For classes, the method name is derived from the
2864method name for the corresponding not-in-place operator by inserting
2865an 'i' in front of the name, e.g. __iadd__ implements in-place
2866__add__.
2867
2868Augmented assignment was implemented by Thomas Wouters.
2869
2870
2871List Comprehensions
2872-------------------
2873
2874This is a flexible new notation for lists whose elements are computed
2875from another list (or lists). The simplest form is:
2876
2877 [<expression> for <variable> in <sequence>]
2878
Guido van Rossum56db0952000-09-06 23:34:25 +00002879For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002880This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002881
2882You can also add a condition:
2883
2884 [<expression> for <variable> in <sequence> if <condition>]
2885
2886For example, [w for w in words if w == w.lower()] would yield the list
2887of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002888than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002889
2890You can also have nested for loops and more than one 'if' clause. For
2891example, here's a function that flattens a sequence of sequences::
2892
2893 def flatten(seq):
2894 return [x for subseq in seq for x in subseq]
2895
2896 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2897
2898This prints
2899
2900 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2901
2902List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002903Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002904
2905
2906Extended Import Statement
2907-------------------------
2908
2909Many people have asked for a way to import a module under a different
2910name. This can be accomplished like this:
2911
2912 import foo
2913 bar = foo
2914 del foo
2915
2916but this common idiom gets old quickly. A simple extension of the
2917import statement now allows this to be written as follows:
2918
2919 import foo as bar
2920
2921There's also a variant for 'from ... import':
2922
2923 from foo import bar as spam
2924
2925This also works with packages; e.g. you can write this:
2926
2927 import test.regrtest as regrtest
2928
2929Note that 'as' is not a new keyword -- it is recognized only in this
2930context (this is only possible because the syntax for the import
2931statement doesn't involve expressions).
2932
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002933Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002934
2935
2936Extended Print Statement
2937------------------------
2938
2939Easily the most controversial new feature, this extension to the print
2940statement adds an option to make the output go to a different file
2941than the default sys.stdout.
2942
2943For example, to write an error message to sys.stderr, you can now
2944write:
2945
2946 print >> sys.stderr, "Error: bad dog!"
2947
2948As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002949evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002950
2951 print >> None, "Hello world"
2952
2953is equivalent to
2954
2955 print "Hello world"
2956
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002957Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002958
2959
2960Optional Collection of Cyclical Garbage
2961---------------------------------------
2962
2963Python is now equipped with a garbage collector that can hunt down
2964cyclical references between Python objects. It's no replacement for
2965reference counting; in fact, it depends on the reference counts being
2966correct, and decides that a set of objects belong to a cycle if all
2967their reference counts can be accounted for from their references to
2968each other. This devious scheme was first proposed by Eric Tiedemann,
2969and brought to implementation by Neil Schemenauer.
2970
2971There's a module "gc" that lets you control some parameters of the
2972garbage collection. There's also an option to the configure script
2973that lets you enable or disable the garbage collection. In 2.0b1,
2974it's on by default, so that we (hopefully) can collect decent user
2975experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002976performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002977off by default in the final 2.0 release.
2978
2979
2980Smaller Changes
2981---------------
2982
2983A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2984map(None, seq1, seq2, ...) when the sequences have the same length;
2985i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2986the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002987zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002988
2989sys.version_info is a tuple (major, minor, micro, level, serial).
2990
2991Dictionaries have an odd new method, setdefault(key, default).
2992dict.setdefault(key, default) returns dict[key] if it exists; if not,
2993it sets dict[key] to default and returns that value. Thus:
2994
2995 dict.setdefault(key, []).append(item)
2996
2997does the same work as this common idiom:
2998
2999 if not dict.has_key(key):
3000 dict[key] = []
3001 dict[key].append(item)
3002
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003003There are two new variants of SyntaxError that are raised for
3004indentation-related errors: IndentationError and TabError.
3005
3006Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3007escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003008
3009The limits on the size of expressions and file in Python source code
3010have been raised from 2**16 to 2**32. Previous versions of Python
3011were limited because the maximum argument size the Python VM accepted
3012was 2**16. This limited the size of object constructor expressions,
3013e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3014limit was raised thanks to a patch by Charles Waldman that effectively
3015fixes the problem. It is now much more likely that you will be
3016limited by available memory than by an arbitrary limit in Python.
3017
3018The interpreter's maximum recursion depth can be modified by Python
3019programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3020limit is the maximum number of recursive calls that can be made by
3021Python code. The limit exists to prevent infinite recursion from
3022overflowing the C stack and causing a core dump. The default value is
30231000. The maximum safe value for a particular platform can be found
3024by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003025
3026New Modules and Packages
3027------------------------
3028
3029atexit - for registering functions to be called when Python exits.
3030
3031imputil - Greg Stein's alternative API for writing custom import
3032hooks.
3033
3034pyexpat - an interface to the Expat XML parser, contributed by Paul
3035Prescod.
3036
3037xml - a new package with XML support code organized (so far) in three
3038subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3039would fill a volume. There's a special feature whereby a
3040user-installed package named _xmlplus overrides the standard
3041xmlpackage; this is intended to give the XML SIG a hook to distribute
3042backwards-compatible updates to the standard xml package.
3043
3044webbrowser - a platform-independent API to launch a web browser.
3045
3046
Guido van Rossume905e952000-09-05 12:42:46 +00003047Changed Modules
3048---------------
3049
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003050array -- new methods for array objects: count, extend, index, pop, and
3051remove
3052
3053binascii -- new functions b2a_hex and a2b_hex that convert between
3054binary data and its hex representation
3055
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003056calendar -- Many new functions that support features including control
3057over which day of the week is the first day, returning strings instead
3058of printing them. Also new symbolic constants for days of week,
3059e.g. MONDAY, ..., SUNDAY.
3060
3061cgi -- FieldStorage objects have a getvalue method that works like a
3062dictionary's get method and returns the value attribute of the object.
3063
3064ConfigParser -- The parser object has new methods has_option,
3065remove_section, remove_option, set, and write. They allow the module
3066to be used for writing config files as well as reading them.
3067
3068ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003069optionally support the RFC 959 REST command.
3070
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003071gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003072
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003073httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3074the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003075
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003076locale -- implement getdefaultlocale for Win32 and Macintosh
3077
3078marshal -- no longer dumps core when marshaling deeply nested or
3079recursive data structures
3080
3081os -- new functions isatty, seteuid, setegid, setreuid, setregid
3082
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003083os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3084support under Unix.
3085
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003086os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003087
3088os.path -- fix semantics of os.path.commonprefix
3089
3090smtplib -- support for sending very long messages
3091
3092socket -- new function getfqdn()
3093
3094readline -- new functions to read, write and truncate history files.
3095The readline section of the library reference manual contains an
3096example.
3097
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003098select -- add interface to poll system call
3099
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003100shutil -- new copyfileobj function
3101
3102SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3103HTTP server.
3104
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003105Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003106
3107urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003108e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003109
3110whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003111
3112
3113Obsolete Modules
3114----------------
3115
3116None. However note that 1.6 made a whole slew of modules obsolete:
3117stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3118poly, zmod, strop, util, whatsound.
3119
3120
3121Changed, New, Obsolete Tools
3122----------------------------
3123
Tim Peters8b092332000-09-05 20:15:25 +00003124None.
Guido van Rossume905e952000-09-05 12:42:46 +00003125
3126
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003127C-level Changes
3128---------------
3129
3130Several cleanup jobs were carried out throughout the source code.
3131
3132All C code was converted to ANSI C; we got rid of all uses of the
3133Py_PROTO() macro, which makes the header files a lot more readable.
3134
3135Most of the portability hacks were moved to a new header file,
3136pyport.h; several other new header files were added and some old
3137header files were removed, in an attempt to create a more rational set
3138of header files. (Few of these ever need to be included explicitly;
3139they are all included by Python.h.)
3140
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003141Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003142and Win64, especially for the new Intel Itanium processor. Mick also
3143added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003144
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003145The C APIs to return an object's size have been update to consistently
3146use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3147previous versions, the abstract interfaces used PyXXX_Length and the
3148concrete interfaces used PyXXX_Size. The old names,
3149e.g. PyObject_Length, are still available for backwards compatibility
3150at the API level, but are deprecated.
3151
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003152The PyOS_CheckStack function has been implemented on Windows by
3153Fredrik Lundh. It prevents Python from failing with a stack overflow
3154on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003155
3156The GC changes resulted in creation of two new slots on object,
3157tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003158the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003159
3160The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003161C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003162
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003163PyErr_Format has been updated to automatically calculate the size of
3164the buffer needed to hold the formatted result string. This change
3165prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003166
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003167New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003168
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003169PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3170that are the same as their non-Ex counterparts except they take an
3171extra flag argument that tells them to close the file when done.
3172
3173XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003174
Tim Peters8b092332000-09-05 20:15:25 +00003175
3176Windows Changes
3177---------------
3178
3179New popen2/popen3/peopen4 in os module (see Changed Modules above).
3180
3181os.popen is much more usable on Windows 95 and 98. See Microsoft
3182Knowledge Base article Q150956. The Win9x workaround described there
3183is implemented by the new w9xpopen.exe helper in the root of your
3184Python installation. Note that Python uses this internally; it is not
3185a standalone program.
3186
3187Administrator privileges are no longer required to install Python
3188on Windows NT or Windows 2000. If you have administrator privileges,
3189Python's registry info will be written under HKEY_LOCAL_MACHINE.
3190Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003191under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003192uses of Python, but will prevent some advanced uses from working
3193(for example, running a Python script as an NT service, or possibly
3194from CGI).
3195
3196[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3197installer; instead, it installs the needed Tcl/Tk files directly in the
3198Python directory. If you already have a Tcl/Tk installation, this
3199wastes some disk space (about 4 Megs) but avoids problems with
3200conflicting Tcl/Tk installations, and makes it much easier for Python
3201to ensure that Tcl/Tk can find all its files.
3202
3203[This was new in 1.6] The Windows installer now installs by default in
3204\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3205
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003206
3207Updates to the changes between 1.5.2 and 1.6
3208--------------------------------------------
3209
3210The 1.6 NEWS file can't be changed after the release is done, so here
3211is some late-breaking news:
3212
3213New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3214and changes to getlocale() and setlocale().
3215
3216The new module is now enabled per default.
3217
3218It is not true that the encodings codecs cannot be used for normal
3219strings: the string.encode() (which is also present on 8-bit strings
3220!) allows using them for 8-bit strings too, e.g. to convert files from
3221cp1252 (Windows) to latin-1 or vice-versa.
3222
3223Japanese codecs are available from Tamito KAJIYAMA:
3224http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3225
3226
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003227======================================================================