blob: 9ef6912fbd14d485b45c5488a5386d467ddda088 [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
15Library
16
Guido van Rossum606fe4e2001-12-28 20:57:14 +000017- ftplib: to safeguard the user's privacy, anonymous login will use
18 "anonymous@" as default password, rather than the real user and host
19 name.
20
Tim Petersaf8446f2001-12-21 21:36:50 +000021Tools/Demos
22
23Build
24
25C API
26
Tim Peters10a3bb52001-12-25 19:07:38 +000027- An old #define of ANY as void has been removed from pyport.h. This
28 hasn't been used since Python's pre-ANSI days, and the #define has
29 been marked as obsolete since then. SF bug 495548 says it created
30 conflicts with other packages, so keeping it around wasn't harmless.
31
Tim Petersaf8446f2001-12-21 21:36:50 +000032- Because Python's magic number scheme broke on January 1st, we decided
33 to stop Python development. Thanks for all the fish!
34
35New platforms
36
Martin v. Löwisa6e97582002-01-01 18:41:33 +000037- GNU/Hurd is now supported.
38
Tim Petersaf8446f2001-12-21 21:36:50 +000039Tests
40
41Windows
42
43Mac
44
45
Tim Peters909c0912001-12-14 23:16:18 +000046What's New in Python 2.2 final?
47Release date: 21-Dec-2001
48===============================
49
50Type/class unification and new-style classes
51
Barry Warsaw52acb492001-12-21 20:04:22 +000052- pickle.py, cPickle: allow pickling instances of new-style classes
53 with a custom metaclass.
54
Tim Peters909c0912001-12-14 23:16:18 +000055Core and builtins
56
Barry Warsaw52acb492001-12-21 20:04:22 +000057- weakref proxy object: when comparing, unwrap both arguments if both
58 are proxies.
59
Tim Peters909c0912001-12-14 23:16:18 +000060Extension modules
61
Barry Warsaw52acb492001-12-21 20:04:22 +000062- binascii.b2a_base64(): fix a potential buffer overrun when encoding
63 very short strings.
64
65- cPickle: the obscure "fast" mode was suspected of causing stack
66 overflows on the Mac. Hopefully fixed this by setting the recursion
67 limit much smaller. If the limit is too low (it only affects
68 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
69 when compiling cPickle.c (or in pyconfig.h).
70
Tim Peters909c0912001-12-14 23:16:18 +000071Library
72
Barry Warsaw52acb492001-12-21 20:04:22 +000073- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
74 close or delete time).
75
76- rfc822.py: fixed a bug where the address '<>' was converted to None
77 instead of an empty string (also fixes the email.Utils module).
78
79- xmlrpclib.py: version 1.0.0; uses precision for doubles.
80
81- test suite: the pickle and cPickle tests were not executing any code
82 when run from the standard regresssion test.
83
Tim Peters909c0912001-12-14 23:16:18 +000084Tools/Demos
85
86Build
87
88C API
89
90New platforms
91
92Tests
93
94Windows
95
Barry Warsaw52acb492001-12-21 20:04:22 +000096- distutils package: fixed broken Windows installers (bdist_wininst).
97
98- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
99 instances are deleted at process exit time.
100
101- socket.py: prevent mysterious warnings when socket instances are
102 deleted at process exit time.
103
104- posixmodule.c: fix a Windows crash with stat() of a filename ending
105 in backslash.
106
Tim Peters909c0912001-12-14 23:16:18 +0000107Mac
108
Barry Warsaw52acb492001-12-21 20:04:22 +0000109- The Carbon toolbox modules have been upgraded to Universal Headers
110 3.4, and experimental CoreGraphics and CarbonEvents modules have
111 been added. All only for framework-enabled MacOSX.
112
Tim Peters909c0912001-12-14 23:16:18 +0000113
Tim Peters6272dfd2001-12-13 19:34:00 +0000114What's New in Python 2.2c1?
115Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000116===========================
117
118Type/class unification and new-style classes
119
Barry Warsaw06557452001-12-14 20:47:12 +0000120- Guido's tutorial introduction to the new type/class features has
121 been extensively updated. See
122
123 http://www.python.org/2.2/descrintro.html
124
125 That remains the primary documentation in this area.
126
Guido van Rossum33bab012001-12-05 22:45:48 +0000127- Fixed a leak: instance variables declared with __slots__ were never
128 deleted!
129
Guido van Rossum4b800852001-12-03 00:54:52 +0000130- The "delete attribute" method of descriptor objects is called
131 __delete__, not __del__. In previous releases, it was mistakenly
132 called __del__, which created an unfortunate overloading condition
133 with finalizers. (The "get attribute" and "set attribute" methods
134 are still called __get__ and __set__, respectively.)
135
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000136- Some subtle issues with the super built-in were fixed:
137
138 (a) When super itself is subclassed, its __get__ method would still
139 return an instance of the base class (i.e., of super).
140
141 (b) super(C, C()).__class__ would return C rather than super. This
142 is confusing. To fix this, I decided to change the semantics of
143 super so that it only applies to code attributes, not to data
144 attributes. After all, overriding data attributes is not
145 supported anyway.
146
147 (c) The __get__ method didn't check whether the argument was an
148 instance of the type used in creation of the super instance.
149
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000150- Previously, hash() of an instance of a subclass of a mutable type
151 (list or dictionary) would return some value, rather than raising
152 TypeError. This has been fixed. Also, directly calling
153 dict.__hash__ and list.__hash__ now raises the same TypeError
154 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000155
Guido van Rossumd331cb52001-12-05 19:46:42 +0000156- New-style objects now support deleting their __dict__. This is for
157 all intents and purposes equivalent to assigning a brand new empty
158 dictionary, but saves space if the object is not used further.
159
Tim Petersb3c9af12001-11-17 00:21:57 +0000160Core and builtins
161
Tim Peters3caca232001-12-06 06:23:26 +0000162- -Qnew now works as documented in PEP 238: when -Qnew is passed on
163 the command line, all occurrences of "/" use true division instead
164 of classic division. See the PEP for details. Note that "all"
165 means all instances in library and 3rd-party modules, as well as in
166 your own code. As the PEP says, -Qnew is intended for use only in
167 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000168 Note that test_coercion.py in the standard Python test suite fails
169 under -Qnew; this is expected, and won't be repaired until true
170 division becomes the default (in the meantime, test_coercion is
171 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000172
Fred Drake6c01e252001-12-14 17:08:12 +0000173- complex() now only allows the first argument to be a string
174 argument, and raises TypeError if either the second arg is a string
175 or if the second arg is specified when the first is a string.
176
Tim Petersb3c9af12001-11-17 00:21:57 +0000177Extension modules
178
Martin v. Löwis560da622001-11-24 09:24:51 +0000179- gc.get_referents was renamed to gc.get_referrers.
180
Tim Petersb3c9af12001-11-17 00:21:57 +0000181Library
182
Tim Peters25059d32001-12-07 20:35:43 +0000183- Functions in the os.spawn() family now release the global interpreter
184 lock around calling the platform spawn. They should always have done
185 this, but did not before 2.2c1. Multithreaded programs calling
186 an os.spawn function with P_WAIT will no longer block all Python threads
187 until the spawned program completes. It's possible that some programs
188 relies on blocking, although more likely by accident than by design.
189
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000190- webbrowser defaults to netscape.exe on OS/2 now.
191
Martin v. Löwis652e1912001-11-25 14:50:56 +0000192- Tix.ResizeHandle exposes detach_widget, hide, and show.
193
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000194- The charset alias windows_1252 has been added.
195
Barry Warsaw06557452001-12-14 20:47:12 +0000196- types.StringTypes is a tuple containing the defined string types;
197 usually this will be (str, unicode), but if Python was compiled
198 without Unicode support it will be just (str,).
199
200- The pulldom and minidom modules were synchronized to PyXML.
201
Tim Petersb3c9af12001-11-17 00:21:57 +0000202Tools/Demos
203
Barry Warsaw06557452001-12-14 20:47:12 +0000204- A new script called Tools/scripts/google.py was added, which fires
205 off a search on Google.
206
Tim Petersb3c9af12001-11-17 00:21:57 +0000207Build
208
Barry Warsaw06557452001-12-14 20:47:12 +0000209- Note that release builds of Python should arrange to define the
210 preprocessor symbol NDEBUG on the command line (or equivalent).
211 In the 2.2 pre-release series we tried to define this by magic in
212 Python.h instead, but it proved to cause problems for extension
213 authors. The Unix, Windows and Mac builds now all define NDEBUG in
214 release builds via cmdline (or equivalent) instead. Ports to
215 other platforms should do likewise.
216
Jack Jansen1999ef42001-12-06 21:47:20 +0000217- It is no longer necessary to use --with-suffix when building on a
218 case-insensitive file system (such as Mac OS X HFS+). In the build
219 directory an extension is used, but not in the installed python.
220
Tim Petersb3c9af12001-11-17 00:21:57 +0000221C API
222
Tim Petersf582b822001-12-11 18:51:08 +0000223- New function PyDict_MergeFromSeq2() exposes the builtin dict
224 constructor's logic for updating a dictionary from an iterable object
225 producing key-value pairs.
226
Tim Peterscffed4b2001-11-29 03:26:37 +0000227- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000228 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000229 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
230 dump core in some bad cases. This has been repaired. As a result,
231 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
232 previously went unchallenged.
233
Tim Petersb3c9af12001-11-17 00:21:57 +0000234New platforms
235
236Tests
237
238Windows
239
240Mac
241
Jack Jansenffa260f2001-12-06 21:14:00 +0000242- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
243 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000244
Barry Warsaw06557452001-12-14 20:47:12 +0000245- Changed logic for finding python home in Mac OS X framework Pythons.
246 Now sys.executable points to the executable again, in stead of to
247 the shared library. The latter is used only for locating the python
248 home.
249
250
Tim Peters84362bc2001-10-19 17:55:30 +0000251What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000252Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000253===========================
254
255Type/class unification and new-style classes
256
Guido van Rossum3d27df02001-11-15 20:27:54 +0000257- Multiple inheritance mixing new-style and classic classes in the
258 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000259
260 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000261 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000262
263 The MRO (method resolution order) for each base class is respected
264 according to its kind, but the MRO for the derived class is computed
265 using new-style MRO rules if any base clase is a new-style class.
266 This needs to be documented.
267
Tim Petersa427a2b2001-10-29 22:25:45 +0000268- The new builtin dictionary() constructor, and dictionary type, have
269 been renamed to dict. This reflects a decade of common usage.
270
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000271- dict() now accepts an iterable object producing 2-sequences. For
272 example, dict(d.items()) == d for any dictionary d. The argument,
273 and the elements of the argument, can be any iterable objects.
274
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000275- New-style classes can now have a __del__ method, which is called
276 when the instance is deleted (just like for classic classes).
277
Guido van Rossum12d955c2001-10-26 14:56:06 +0000278- Assignment to object.__dict__ is now possible, for objects that are
279 instances of new-style classes that have a __dict__ (unless the base
280 class forbids it).
281
Guido van Rossumc8e56452001-10-22 00:43:43 +0000282- Methods of built-in types now properly check for keyword arguments
283 (formerly these were silently ignored). The only built-in methods
284 that take keyword arguments are __call__, __init__ and __new__.
285
Guido van Rossum86443212001-10-27 22:28:54 +0000286- The socket function has been converted to a type; see below.
287
Tim Peters84362bc2001-10-19 17:55:30 +0000288Core and builtins
289
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000290- Assignment to __debug__ raises SyntaxError at compile-time. This
291 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000292 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000293
Guido van Rossum12d955c2001-10-26 14:56:06 +0000294- Clarified the error messages for unsupported operands to an operator
295 (like 1 + '').
296
Tim Peters84362bc2001-10-19 17:55:30 +0000297Extension modules
298
Tim Peters5ebfd362001-11-13 23:11:19 +0000299- mmap has a new keyword argument, "access", allowing a uniform way for
300 both Windows and Unix users to create read-only, write-through and
301 copy-on-write memory mappings. This was previously possible only on
302 Unix. A new keyword argument was required to support this in a
303 uniform way because the mmap() signuatures had diverged across
304 platforms. Thanks to Jay T Miller for repairing this!
305
Tim Peters169ded02001-11-03 19:57:21 +0000306- By default, the gc.garbage list now contains only those instances in
307 unreachable cycles that have __del__ methods; in 2.1 it contained all
308 instances in unreachable cycles. "Instances" here has been generalized
309 to include instances of both new-style and old-style classes.
310
Guido van Rossum12d955c2001-10-26 14:56:06 +0000311- The socket module defines a new method for socket objects,
312 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000313 send() until all data has been sent. Also, the socket function has
314 been converted to a subclassable type, like list and tuple (etc.)
315 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000316
317- Various bugfixes to the curses module. There is now a test suite
318 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000319
Guido van Rossum692adf12001-10-30 03:03:03 +0000320- binascii.b2a_base64 no longer places an arbitrary restriction of 57
321 bytes on its input.
322
Tim Peters84362bc2001-10-19 17:55:30 +0000323Library
324
Tim Peters5ebfd362001-11-13 23:11:19 +0000325- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000326 convenience function.
327
Tim Peters75335872001-11-03 19:35:43 +0000328- Symbolic group names in regular expressions must be unique. For
329 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
330 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000331 Python 2.2 detects this error at regexp compilation time;
332 previously, the error went undetected, and results were
333 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
334 pattern.subn() methods have been rewritten in C. Also, an
335 experimental function/method finditer() has been added, which works
336 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000337
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000338- Tix exposes more commands through the classes DirSelectBox,
339 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
340 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
341 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
342
Tim Peters98791af2001-10-23 01:59:54 +0000343- Traceback objects are now scanned by cyclic garbage collection, so
344 cycles created by casual use of sys.exc_info() no longer cause
345 permanent memory leaks (provided garbage collection is enabled).
346
Guido van Rossum49192142001-10-24 20:51:44 +0000347- os.extsep -- a new variable needed by the RISCOS support. It is the
348 separator used by extensions, and is '.' on all platforms except
349 RISCOS, where it is '/'. There is no need to use this variable
350 unless you have a masochistic desire to port your code to RISCOS.
351
Barry Warsaw012852b2001-11-16 16:17:27 +0000352- mimetypes.py has optional support for non-standard, but commonly
353 found types. guess_type() and guess_extension() now accept an
354 optional `strict' flag, defaulting to true, which controls whether
355 recognize non-standard types or not. A few non-standard types we
356 know about have been added. Also, when run as a script, there are
357 new -l and -e options.
358
359- statcache is now deprecated.
360
361- email.Utils.formatdate() now produces the preferred RFC 2822 style
362 dates with numeric timezones (it used to produce obsolete dates
363 hard coded to "GMT" timezone). An optional `localtime' flag is
364 added to produce dates in the local timezone, with daylight savings
365 time properly taken into account.
366
367- In pickle and cPickle, instead of masking errors in load() by
368 transforming them into SystemError, we let the original exception
369 propagate out. Also, implement support for __safe_for_unpickling__
370 in pickle, as it already was supported in cPickle.
371
Tim Peters84362bc2001-10-19 17:55:30 +0000372Tools/Demos
373
374Build
375
Barry Warsaw012852b2001-11-16 16:17:27 +0000376- The dbm module is built using libdb1 if available. The bsddb module
377 is built with libdb3 if available.
378
379- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
380
Tim Peters84362bc2001-10-19 17:55:30 +0000381C API
382
Tim Peters1fc240e2001-10-26 05:06:50 +0000383- New function PySequence_Fast_GET_SIZE() returns the size of a non-
384 NULL result from PySequence_Fast(), more quickly than calling
385 PySequence_Size().
386
Barry Warsaw012852b2001-11-16 16:17:27 +0000387- New argument unpacking function PyArg_UnpackTuple() added.
388
389- New functions PyObject_CallFunctionObjArgs() and
390 PyObject_CallMethodObjArgs() have been added to make it more
391 convenient and efficient to call functions and methods from C.
392
393- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
394 possible that this will propagate errors it didn't before.
395
396- New function PyObject_CheckReadBuffer(), which returns true if its
397 argument supports the single-segment readable buffer interface.
398
Tim Peters84362bc2001-10-19 17:55:30 +0000399New platforms
400
Guido van Rossum86443212001-10-27 22:28:54 +0000401- We've finally confirmed that this release builds on HP-UX 11.00,
402 *with* threads, and passes the test suite.
403
Tim Peters7a33d8b2001-11-05 02:51:07 +0000404- Thanks to a series of patches from Michael Muller, Python may build
405 again under OS/2 Visual Age C++.
406
Guido van Rossum49192142001-10-24 20:51:44 +0000407- Updated RISCOS port by Dietmar Schwertberger.
408
Tim Peters84362bc2001-10-19 17:55:30 +0000409Tests
410
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000411- Added a test script for the curses module. It isn't run automatically;
412 regrtest.py must be run with '-u curses' to enable it.
413
Tim Peters84362bc2001-10-19 17:55:30 +0000414Windows
415
Barry Warsaw012852b2001-11-16 16:17:27 +0000416Mac
417
418- PythonScript has been moved to unsupported and is slated to be
419 removed completely in the next release.
420
421- It should now be possible to build applets that work on both OS9 and
422 OSX.
423
424- The core is now linked with CoreServices not Carbon; as a side
425 result, default 8bit encoding on OSX is now ASCII.
426
427- Python should now build on OSX 10.1.1
428
Tim Peters84362bc2001-10-19 17:55:30 +0000429
Tim Petersabf925f2001-09-28 21:53:42 +0000430What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000431Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000432===========================
433
434Type/class unification and new-style classes
435
Guido van Rossum687ae002001-10-15 22:03:32 +0000436- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000437 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000438 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000439 remains: the __dict__ of a new-style class is a read-only proxy; you
440 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000441 __defined__ attribute of new-style types no longer exists, for lack
442 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000443 future a __cache__ may be resurrected with a similar function, if I
444 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000445
Tim Peters1c9ca872001-10-04 06:43:12 +0000446- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
447 always returned None, even when there was a class docstring).
448
449- doctest now finds and runs docstrings attached to new-style classes,
450 class methods, static methods, and properties.
451
Guido van Rossum9074ef62001-10-16 21:34:49 +0000452Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000453
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000454- A very subtle syntactical pitfall in list comprehensions was fixed.
455 For example: [a+b for a in 'abc', for b in 'def']. The comma in
456 this example is a mistake. Previously, this would silently let 'a'
457 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
458 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
459 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
460 Note that [a for a in <singleton>] is a convoluted way to say
461 [<singleton>] anyway, so it's not like any expressiveness is lost.
462
Guido van Rossum9074ef62001-10-16 21:34:49 +0000463- getattr(obj, name, default) now only catches AttributeError, as
464 documented, rather than returning the default value for all
465 exceptions (which could mask bugs in a __getattr__ hook, for
466 example).
467
Fred Drakecb7a6b52001-10-22 18:41:51 +0000468- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000469 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000470 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000471 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000472
Guido van Rossum1c486092001-10-19 02:05:35 +0000473- unicode(obj) now behaves more like str(obj), accepting arbitrary
474 objects, and calling a __unicode__ method if it exists.
475 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000476 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000477
Barry Warsawf6fb1712001-10-19 05:35:40 +0000478- isinstance() now allows any object as the first argument and a
479 class, a type or something with a __bases__ tuple attribute for the
480 second argument. The second argument may also be a tuple of a
481 class, type, or something with __bases__, in which case isinstance()
482 will return true if the first argument is an instance of any of the
483 things contained in the second argument tuple. E.g.
484
485 isinstance(x, (A, B))
486
487 returns true if x is an instance of A or B.
488
Guido van Rossum9074ef62001-10-16 21:34:49 +0000489Extension modules
490
491- thread.start_new_thread() now returns the thread ID (previously None).
492
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000493- binascii has now two quopri support functions, a2b_qp and b2a_qp.
494
Guido van Rossumc524d952001-10-19 01:31:59 +0000495- readline now supports setting the startup_hook and the
496 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000497
Guido van Rossumc524d952001-10-19 01:31:59 +0000498- os and posix supports chroot(), setgroups() and unsetenv() where
499 available. The stat(), fstat(), statvfs() and fstatvfs() functions
500 now return "pseudo-sequences" -- the various fields can now be
501 accessed as attributes (e.g. os.stat("/").st_mtime) but for
502 backwards compatibility they also behave as a fixed-length sequence.
503 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000504 attributes.
505
506- time: localtime(), gmtime() and strptime() now return a
507 pseudo-sequence similar to the os.stat() return value, with
508 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000509
Guido van Rossum9074ef62001-10-16 21:34:49 +0000510- Decompression objects in the zlib module now accept an optional
511 second parameter to decompress() that specifies the maximum amount
512 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000513
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000514- optional SSL support in the socket module now exports OpenSSL
515 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
516 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000517 automatically seed its PRNG. Also, the keyfile and certfile
518 arguments to socket.ssl() are now optional.
519
520- posixmodule (and by extension, the os module on POSIX platforms) now
521 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000522
Guido van Rossum9074ef62001-10-16 21:34:49 +0000523Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000524
Tim Peters7402f792001-10-02 03:53:41 +0000525- doctest now excludes functions and classes not defined by the module
526 being tested, thanks to Tim Hochberg.
527
Fred Drakecb7a6b52001-10-22 18:41:51 +0000528- HotShot, a new profiler implemented using a C-based callback, has
529 been added. This substantially reduces the overhead of profiling,
530 but it is still quite preliminary. Support modules and
531 documentation will be added in upcoming releases (before 2.2 final).
532
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000533- profile now produces correct output in situations where an exception
534 raised in Python is cleared by C code (e.g. hasattr()). This used
535 to cause wrong output, including spurious claims of recursive
536 functions and attribution of time spent to the wrong function.
537
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000538 The code and documentation for the derived OldProfile and HotProfile
539 profiling classes was removed. The code hasn't worked for years (if
540 you tried to use them, they raised exceptions). OldProfile
541 intended to reproduce the behavior of the profiler Python used more
542 than 7 years ago, and isn't interesting anymore. HotProfile intended
543 to provide a faster profiler (but producing less information), and
544 that's a worthy goal we intend to meet via a different approach (but
545 without losing information).
546
Tim Peterscce092d2001-10-09 05:31:56 +0000547- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000548 a much better system-specific calibration constant. The constant can
549 now be specified in an instance constructor, or as a Profile class or
550 instance variable, instead of by editing profile.py's source code.
551 Calibration must still be done manually (see the docs for the profile
552 module).
553
554 Note that Profile.calibrate() must be overriden by subclasses.
555 Improving the accuracy required exploiting detailed knowledge of
556 profiler internals; the earlier method abstracted away the details
557 and measured a simplified model instead, but consequently computed
558 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000559
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000560- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000561 which indicates whether output is intended for the header 'Q'
562 encoding.
563
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000564- The SocketServer.ThreadingMixIn class now closes the request after
565 finish_request() returns. (Not when it errors out though.)
566
Barry Warsawf6fb1712001-10-19 05:35:40 +0000567- The nntplib module's NNTP.body() method has grown a `file' argument
568 to allow saving the message body to a file.
569
570- The email package has added a class email.Parser.HeaderParser which
571 only parses headers and does not recurse into the message's body.
572 Also, the module/class MIMEAudio has been added for representing
573 audio data (contributed by Anthony Baxter).
574
575- ftplib should be able to handle files > 2GB.
576
577- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
578 ON, and OFF.
579
Fred Drakecb7a6b52001-10-22 18:41:51 +0000580- xml.dom.minidom NodeList objects now support the length attribute
581 and item() method as required by the DOM specifications.
582
Guido van Rossumed554f62001-10-02 23:15:37 +0000583Tools/Demos
584
585- Demo/dns was removed. It no longer serves any purpose; a package
586 derived from it is now maintained by Anthony Baxter, see
587 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000588
Barry Warsawf6fb1712001-10-19 05:35:40 +0000589- The freeze tool has been made more robust, and two new options have
590 been added: -X and -E.
591
Tim Petersabf925f2001-09-28 21:53:42 +0000592Build
593
Barry Warsawf6fb1712001-10-19 05:35:40 +0000594- configure will use CXX in LINKCC if CXX is used to build main() and
595 the system requires to link a C++ main using the C++ compiler.
596
Tim Petersabf925f2001-09-28 21:53:42 +0000597C API
598
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000599- The documentation for the tp_compare slot is updated to require that
600 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
601 not correct. This is not yet enforced but will be enforced in
602 Python 2.3; even later, we may use -2 to indicate errors and +2 for
603 "NotImplemented". Right now, -1 should be used for an error return.
604
Tim Petersd38b1c72001-09-30 05:09:37 +0000605- PyLong_AsLongLong() now accepts int (as well as long) arguments.
606 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
607 as long) arguments.
608
Guido van Rossum3c288632001-10-16 21:13:49 +0000609- PyThread_start_new_thread() now returns a long int giving the thread
610 ID, if one can be calculated; it returns -1 for error, 0 if no
611 thread ID is calculated (this is an incompatible change, but only
612 the thread module used this API). This code has only really been
613 tested on Linux and Windows; other platforms please beware (and
614 report any bugs or strange behavior).
615
Guido van Rossum1c486092001-10-19 02:05:35 +0000616- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
617 input.
618
Tim Petersabf925f2001-09-28 21:53:42 +0000619New platforms
620
621Tests
622
623Windows
624
Tim Peters04cf1d32001-10-09 22:39:40 +0000625- Installer: If you install IDLE, and don't disable file-extension
626 registration, a new "Edit with IDLE" context (right-click) menu entry
627 is created for .py and .pyw files.
628
Tim Peters1ce3cf72001-10-01 17:58:40 +0000629- The signal module now supports SIGBREAK on Windows, thanks to Steven
630 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
631 action remains to call Win32 ExitProcess(). This can be changed via
632 signal.signal(). For example:
633
634 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
635 # (SIGINT) behavior.
636 import signal
637 signal.signal(signal.SIGBREAK,
638 signal.default_int_handler)
639
640 try:
641 while 1:
642 pass
643 except KeyboardInterrupt:
644 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
645 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
646 # program without the possibility for any Python-level cleanup).
647 print "Clean exit"
648
Tim Petersabf925f2001-09-28 21:53:42 +0000649
Tim Petersb07352e2001-09-08 01:25:47 +0000650What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000651Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000652===========================
653
Guido van Rossum808eea72001-09-25 04:15:41 +0000654Type/class unification and new-style classes
655
656- pydoc and inspect are now aware of new-style classes;
657 e.g. help(list) at the interactive prompt now shows proper
658 documentation for all operations on list objects.
659
660- Applications using Jim Fulton's ExtensionClass module can now safely
661 be used with Python 2.2. In particular, Zope 2.4.1 now works with
662 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
663 examples also work again. It is hoped that Gtk and Boost also work
664 with 2.2a4 and beyond. (If you can confirm this, please write
665 webmaster@python.org; if there are still problems, please open a bug
666 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000667
Tim Peters66c1a522001-09-24 21:17:50 +0000668- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
669 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
670 in the constructed property object. fget, fset and fdel weren't
671 discoverable from Python in 2.2a3. __doc__ is new, and allows to
672 associate a docstring with a property.
673
Guido van Rossum808eea72001-09-25 04:15:41 +0000674- Comparison overloading is now more completely implemented. For
675 example, a str subclass instance can properly be compared to a str
676 instance, and it can properly overload comparison. Ditto for most
677 other built-in object types.
678
679- The repr() of new-style classes has changed; instead of <type
680 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
681 *except* for built-in types, which are still rendered as <type
682 'Foo'> (to avoid upsetting existing code that might parse or
683 otherwise rely on repr() of certain type objects).
684
685- The repr() of new-style objects is now always <Foo object at XXX>;
686 previously, it was sometimes <Foo instance at XXX>.
687
688- For new-style classes, what was previously called __getattr__ is now
689 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000690 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000691 one in classic classes is defined which is called only if regular
692 attribute access raises AttributeError; to catch *all* attribute
693 access, you can use __getattribute__ (for new-style classes). If
694 both are defined, __getattribute__ is called first, and if it raises
695 AttributeError, __getattr__ is called.
696
697- The __class__ attribute of new-style objects can be assigned to.
698 The new class must have the same C-level object layout as the old
699 class.
700
701- The builtin file type can be subclassed now. In the usual pattern,
702 "file" is the name of the builtin type, and file() is a new builtin
703 constructor, with the same signature as the builtin open() function.
704 file() is now the preferred way to open a file.
705
706- Previously, __new__ would only see sequential arguments passed to
707 the type in a constructor call; __init__ would see both sequential
708 and keyword arguments. This made no sense whatsoever any more, so
709 now both __new__ and __init__ see all arguments.
710
711- Previously, hash() applied to an instance of a subclass of str or
712 unicode always returned 0. This has been repaired.
713
714- Previously, an operation on an instance of a subclass of an
715 immutable type (int, long, float, complex, tuple, str, unicode),
716 where the subtype didn't override the operation (and so the
717 operation was handled by the builtin type), could return that
718 instance instead a value of the base type. For example, if s was of
719 a str sublass type, s[:] returned s as-is. Now it returns a str
720 with the same value as s.
721
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000722- Provisional support for pickling new-style objects has been added.
723
Guido van Rossum808eea72001-09-25 04:15:41 +0000724Core
725
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000726- file.writelines() now accepts any iterable object producing strings.
727
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000728- PyUnicode_FromEncodedObject() now works very much like
729 PyObject_Str(obj) in that it tries to use __str__/tp_str
730 on the object if the object is not a string or buffer. This
731 makes unicode() behave like str() when applied to non-string/buffer
732 objects.
733
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000734- PyFile_WriteObject now passes Unicode objects to the file's write
735 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000736 of a print statement must support Unicode objects, i.e. they must
737 at least convert them into ASCII strings.
738
Guido van Rossum624c8af2001-09-18 15:21:04 +0000739- Thread scheduling on Solaris should be improved; it is no longer
740 necessary to insert a small sleep at the start of a thread in order
741 to let other runnable threads be scheduled.
742
Tim Petersb07352e2001-09-08 01:25:47 +0000743Library
744
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000745- StringIO.StringIO instances and cStringIO.StringIO instances support
746 read character buffer compatible objects for their .write() methods.
747 These objects are converted to strings and then handled as such
748 by the instances.
749
Barry Warsaw2f600732001-09-24 04:28:10 +0000750- The "email" package has been added. This is basically a port of the
751 mimelib package <http://sf.net/projects/mimelib> with API changes
752 and some implementations updated to use iterators and generators.
753
Tim Peters8a9c2842001-09-22 21:30:22 +0000754- difflib.ndiff() and difflib.Differ.compare() are generators now. This
755 restores the ability of Tools/scripts/ndiff.py to start producing output
756 before the entire comparison is complete.
757
Barry Warsaw58b072d2001-09-22 04:44:21 +0000758- StringIO.StringIO instances and cStringIO.StringIO instances support
759 iteration just like file objects (i.e. their .readline() method is
760 called for each iteration until it returns an empty string).
761
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000762- The codecs module has grown four new helper APIs to access
763 builtin codecs: getencoder(), getdecoder(), getreader(),
764 getwriter().
765
Guido van Rossum624c8af2001-09-18 15:21:04 +0000766- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
767 simplifies writing XML RPC servers.
768
Barry Warsaw647d5e82001-09-28 17:01:02 +0000769- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000770 after interpretation of symbolic links. On non-Unix systems, this
771 is an alias for os.path.abspath().
772
Tim Peters16a77ad2001-09-08 04:00:12 +0000773- operator.indexOf() (PySequence_Index() in the C API) now works with any
774 iterable object.
775
Guido van Rossum624c8af2001-09-18 15:21:04 +0000776- smtplib now supports various authentication and security features of
777 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000778
Guido van Rossum624c8af2001-09-18 15:21:04 +0000779- hmac: a new module implementing keyed hashing for message
780 authentication.
781
782- mimetypes now recognizes more extensions and file types. At the
783 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000784
Guido van Rossum624c8af2001-09-18 15:21:04 +0000785- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000786 Python 2.2 bytecode generation. It has also been promoted from a
787 Tool to a standard library package. (Tools/compiler still exists as
788 a sample driver.)
789
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000790Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000791
Tim Petersb07352e2001-09-08 01:25:47 +0000792Build
793
Guido van Rossum624c8af2001-09-18 15:21:04 +0000794- Large file support (LFS) is now automatic when the platform supports
795 it; no more manual configuration tweaks are needed. On Linux, at
796 least, it's possible to have a system whose C library supports large
797 files but whose kernel doesn't; in this case, large file support is
798 still enabled but doesn't do you any good unless you upgrade your
799 kernel or share your Python executable with another system whose
800 kernel has large file support.
801
802- The configure script now supplies plausible defaults in a
803 cross-compilation environment. This doesn't mean that the supplied
804 values are always correct, or that cross-compilation now works
805 flawlessly -- but it's a first step (and it shuts up most of
806 autoconf's warnings about AC_TRY_RUN).
807
808- The Unix build is now a bit less chatty, courtesy of the parser
809 generator. The build is completely silent (except for errors) when
810 using "make -s", thanks to a -q option to setup.py.
811
Tim Petersb07352e2001-09-08 01:25:47 +0000812C API
813
Guido van Rossum624c8af2001-09-18 15:21:04 +0000814- The "structmember" API now supports some new flag bits to deny read
815 and/or write access to attributes in restricted execution mode.
816
Tim Petersb07352e2001-09-08 01:25:47 +0000817New platforms
818
Guido van Rossum624c8af2001-09-18 15:21:04 +0000819- Compaq's iPAQ handheld, running the "familiar" Linux distribution
820 (http://familiar.handhelds.org).
821
Tim Petersb07352e2001-09-08 01:25:47 +0000822Tests
823
Tim Peters8a9c2842001-09-22 21:30:22 +0000824- The "classic" standard tests, which work by comparing stdout to
825 an expected-output file under Lib/test/output/, no longer stop at
826 the first mismatch. Instead the test is run to completion, and a
827 variant of ndiff-style comparison is used to report all differences.
828 This is much easier to understand than the previous style of reporting.
829
830- The unittest-based standard tests now use regrtest's test_main()
831 convention, instead of running as a side-effect of merely being
832 imported. This allows these tests to be run in more natural and
833 flexible ways as unittests, outside the regrtest framework.
834
835- regrtest.py is much better integrated with unittest and doctest now,
836 especially in regard to reporting errors.
837
Tim Petersb07352e2001-09-08 01:25:47 +0000838Windows
839
Guido van Rossum624c8af2001-09-18 15:21:04 +0000840- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000841 that support it (NTFS under Windows 2000). See "What's New in
842 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000843
Tim Petersb07352e2001-09-08 01:25:47 +0000844
Tim Petersedc99312001-08-22 21:36:50 +0000845What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000846Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000847===========================
848
849Core
850
Tim Peters9fffa3e2001-09-04 05:14:19 +0000851- Conversion of long to float now raises OverflowError if the long is too
852 big to represent as a C double.
853
Tim Peters32f453e2001-09-03 08:35:41 +0000854- The 3-argument builtin pow() no longer allows a third non-None argument
855 if either of the first two arguments is a float, or if both are of
856 integer types and the second argument is negative (in which latter case
857 the arguments are converted to float, so this is really the same
858 restriction).
859
Tim Peters5d2b77c2001-09-03 05:47:38 +0000860- The builtin dir() now returns more information, and sometimes much
861 more, generally naming all attributes of an object, and all attributes
862 reachable from the object via its class, and from its class's base
863 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
864 an empty list. In 2.2a3,
865
866 >>> dir([])
867 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
868 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
869 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
870 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
871 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
872 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
873 'reverse', 'sort']
874
875 dir(module) continues to return only the module's attributes, though.
876
Tim Petersbdee63f2001-09-02 03:40:59 +0000877- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000878 than raising OverflowError. This is a partial implementation of PEP
879 237. You can use -Wdefault::OverflowWarning to enable a warning for
880 this situation, and -Werror::OverflowWarning to revert to the old
881 OverflowError exception.
882
Guido van Rossum61c345f2001-09-04 03:26:15 +0000883- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000884 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000885 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
886 -Qold, meaning the / operator has its classic meaning and no
887 warnings are issued. Using -Qwarn issues a run-time warning about
888 all uses of classic division for int and long arguments; -Qwarnall
889 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000890 (for use with fixdiv.py).
891 [Note: the remainder of this paragraph (preserved below) became
892 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
893 <obsolete>
894 Using -Qnew is questionable; it turns on new division by default, but
895 only in the __main__ module. You can usefully combine -Qwarn or
896 -Qwarnall and -Qnew: this gives the __main__ module new division, and
897 warns about classic division everywhere else.
898 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000899
Tim Petersbdee63f2001-09-02 03:40:59 +0000900- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000901 long, float, str, unicode, and tuple. (The types complex, list and
902 dictionary can also be subclassed; this was introduced earlier.)
903 Note that restrictions apply when subclassing immutable built-in
904 types: you can only affect the value of the instance by overloading
905 __new__. You can add mutable attributes, and the subclass instances
906 will have a __dict__ attribute, but you cannot change the "value"
907 (as implemented by the base class) of an immutable subclass instance
908 once it is created.
909
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000910- The dictionary constructor now takes an optional argument, a
911 mapping-like object, and initializes the dictionary from its
912 (key, value) pairs.
913
Tim Petersbdee63f2001-09-02 03:40:59 +0000914- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000915 "cooperative super calls" in a multiple inheritance setting. For an
916 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
917
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000918- A new built-in type, property, has been added. This enables the
919 creation of "properties". These are attributes implemented by
920 getter and setter functions (or only one of these for read-only or
921 write-only attributes), without the need to override __getattr__.
922 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000923
Tim Petersbdee63f2001-09-02 03:40:59 +0000924- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000925 liberalized, to allow leading zeroes. Examples of literals now
926 legal that were SyntaxErrors before:
927
928 00.0 0e3 0100j 07.5 00000000000000000008.
929
Tim Petersbdee63f2001-09-02 03:40:59 +0000930- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000931 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
932
Tim Petersedc99312001-08-22 21:36:50 +0000933Library
934
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000935- telnetlib includes symbolic names for the options, and support for
936 setting an option negotiation callback.
937
Tim Petersa40c7932001-09-05 22:36:56 +0000938- The new C standard no longer requires that math libraries set errno to
939 ERANGE on overflow. For platform libraries that exploit this new
940 freedom, Python's overflow-checking was wholly broken. A new overflow-
941 checking scheme attempts to repair that, but may not be reliable on all
942 platforms (C doesn't seem to provide anything both useful and portable
943 in this area anymore).
944
Martin v. Löwis44f86962001-09-05 13:44:54 +0000945- Asynchronous timeout actions are available through the new class
946 threading.Timer.
947
Tim Peters78526162001-09-05 00:53:45 +0000948- math.log and math.log10 now return sensible results for even huge
949 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
950
Tim Petersbdee63f2001-09-02 03:40:59 +0000951- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000952 currently held. See the docs for the imp module.
953
Tim Petersbdee63f2001-09-02 03:40:59 +0000954- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000955 dumps containing ints written on platforms where Python ints are 8 bytes.
956 When read on a box where Python ints are 4 bytes, such values are
957 converted to Python longs.
958
Tim Petersbdee63f2001-09-02 03:40:59 +0000959- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000960 code objects is no longer allowed. This plugs a security hole.
961
Steve Purcell6091cd62001-09-06 16:05:17 +0000962- unittest.TestResult instances no longer store references to tracebacks
963 generated by test failures. This prevents unexpected dangling references
964 to objects that should be garbage collected between tests.
965
Tim Petersedc99312001-08-22 21:36:50 +0000966Tools
967
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000968- Tools/scripts/fixdiv.py has been added which can be used to fix
969 division operators as per PEP 238.
970
Tim Petersedc99312001-08-22 21:36:50 +0000971Build
972
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000973- If you are an adventurous person using Mac OS X you may want to look at
974 Mac/OSX. There is a Makefile there that will build Python as a real Mac
975 application, which can be used for experimenting with Carbon or Cocoa.
976 Discussion of this on pythonmac-sig, please.
977
Tim Peters7eea37e2001-09-04 22:08:56 +0000978C API
979
980- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000981
Tim Peters9fffa3e2001-09-04 05:14:19 +0000982- Note that PyLong_AsDouble can fail! This has always been true, but no
983 callers checked for it. It's more likely to fail now, because overflow
984 errors are properly detected now. The proper way to check:
985
986 double x = PyLong_AsDouble(some_long_object);
987 if (x == -1.0 && PyErr_Occurred()) {
988 /* The conversion failed. */
989 }
990
Tim Petersbdee63f2001-09-02 03:40:59 +0000991- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000992 compile but will not participate in GC. To upgrade an extension
993 module:
994
995 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +0000996
Neil Schemenauer4042c692001-08-30 15:38:01 +0000997 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
998 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +0000999
Neil Schemenauer4042c692001-08-30 15:38:01 +00001000 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1001 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001002
Neil Schemenauer4042c692001-08-30 15:38:01 +00001003 - remove PyGC_HEAD_SIZE from object size calculations
1004
1005 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1006
Tim Petersbdee63f2001-09-02 03:40:59 +00001007- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001008 These can be used safely to construct string objects from a
1009 sprintf-style format string (similar to the format string supported
1010 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001011
Tim Petersedc99312001-08-22 21:36:50 +00001012New platforms
1013
Tim Petersb7da0902001-09-02 23:01:43 +00001014- Stephen Hansen contributed patches sufficient to get a clean compile
1015 under Borland C (Windows), but he reports problems running it and ran
1016 out of time to complete the port. Volunteers? Expect a MemoryError
1017 when importing the types module; this is probably shallow, and
1018 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001019
Tim Petersedc99312001-08-22 21:36:50 +00001020Tests
1021
1022Windows
1023
Tim Peters6e13a562001-09-06 00:32:15 +00001024- Large file support is now enabled on Win32 platforms as well as on
1025 Win64. This means that, for example, you can use f.tell() and f.seek()
1026 to manipulate files larger than 2 gigabytes (provided you have enough
1027 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001028 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1029 filesize limit, and large file support makes no difference there.
1030 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1031 NTFS has no practical limit on file size, and files of any size can be
1032 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001033
Tim Petersbdee63f2001-09-02 03:40:59 +00001034- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001035 points to command.com (patch from Brian Quinlan).
1036
Tim Petersedc99312001-08-22 21:36:50 +00001037
Tim Peters20f51a72001-07-21 02:31:40 +00001038What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001039Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001040===========================
1041
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001042Build
1043
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001044- Tim Peters developed a brand new Windows installer using Wise 8.1,
1045 generously donated to us by Wise Solutions.
1046
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001047- configure supports a new option --enable-unicode, with the values
1048 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1049 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001050
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001051- A new configure option --enable-framework builds a Mac OS X framework,
1052 which "make frameworkinstall" will install. This provides a starting
1053 point for more mac-like functionality, join pythonmac-sig@python.org
1054 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001055
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001056- The NeXT platform is no longer supported.
1057
1058- The `new' module is now statically linked.
1059
Tim Peters0afb6092001-08-15 06:06:44 +00001060Tools
1061
1062- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001063 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001064 the module docstring for details.
1065
Tim Peters20f51a72001-07-21 02:31:40 +00001066Tests
1067
Tim Peters5e824c32001-08-12 22:25:01 +00001068- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001069 platforms, allowing to give clearer test result output. regrtest
1070 also has optional --use/-u switch to run normally disabled tests
1071 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001072
Tim Peters20f51a72001-07-21 02:31:40 +00001073- Several new tests in the standard test suite, with special thanks to
1074 Nick Mathewson.
1075
1076Core
1077
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001078- The floor division operator // has been added as outlined in PEP
1079 238. The / operator still provides classic division (and will until
1080 Python 3.0) unless "from __future__ import division" is included, in
1081 which case the / operator will provide true division. The operator
1082 module provides truediv() and floordiv() functions. Augmented
1083 assignment variants are included, as are the equivalent overloadable
1084 methods and C API methods. See the PEP for a full discussion:
1085 <http://python.sf.net/peps/pep-0238.html>
1086
Tim Peters6cd6a822001-08-17 22:11:27 +00001087- Future statements are now effective in simulated interactive shells
1088 (like IDLE). This should "just work" by magic, but read Michael
1089 Hudson's "Future statements in simulated shells" PEP 264 for full
1090 details: <http://python.sf.net/peps/pep-0264.html>.
1091
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001092- The type/class unification (PEP 252-253) was integrated into the
1093 trunk and is not so tentative any more (the exact specification of
1094 some features is still tentative). A lot of work has done on fixing
1095 bugs and adding robustness and features (performance still has to
1096 come a long way).
1097
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001098- Warnings about a mismatch in the Python API during extension import
1099 now use the Python warning framework (which makes it possible to
1100 write filters for these warnings).
1101
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001102- A function's __dict__ (aka func_dict) will now always be a
1103 dictionary. It used to be possible to delete it or set it to None,
1104 but now both actions raise TypeErrors. It is still legal to set it
1105 to a dictionary object. Getting func.__dict__ before any attributes
1106 have been assigned now returns an empty dictionary instead of None.
1107
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001108- A new command line option, -E, was added which disables the use of
1109 all environment variables, or at least those that are specifically
1110 significant to Python. Usually those have a name starting with
1111 "PYTHON". This was used to fix a problem where the tests fail if
1112 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1113 older distribution.
1114
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001115Library
1116
Tim Peters5e824c32001-08-12 22:25:01 +00001117- New class Differ and new functions ndiff() and restore() in difflib.py.
1118 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001119 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001120
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001121- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1122 value using the minimal quoting required for the value; more
1123 reliable than using xml.sax.saxutils.escape() for attribute values.
1124
1125- Readline completion support for cmd.Cmd was added.
1126
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001127- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1128
1129- Added function threading.BoundedSemaphore()
1130
1131- Added Ka-Ping Yee's cgitb.py module.
1132
1133- The `new' module now exposes the CO_xxx flags.
1134
Martin v. Löwis560da622001-11-24 09:24:51 +00001135- The gc module offers the get_referents function.
1136
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001137New platforms
1138
1139C API
1140
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001141- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1142 which provide a cross-platform implementations for the
1143 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1144 the standard sprintf() and vsprintf() C lib APIs, these versions
1145 apply bounds checking on the used buffer which enhances protection
1146 against buffer overruns.
1147
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001148- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001149 and extensions using different Unicode widths is rendered next to
1150 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001151 will result in an ImportError. Unicode extensions writers must make
1152 sure to check the Unicode width compatibility in their extensions by
1153 using at least one of the mangled Unicode APIs in the extension.
1154
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001155- Two new flags METH_NOARGS and METH_O are available in method definition
1156 tables to simplify implementation of methods with no arguments and a
1157 single untyped argument. Calling such methods is more efficient than
1158 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1159 deprecated.
1160
Tim Petersc1731372001-08-04 08:12:36 +00001161Windows
1162
1163- "import module" now compiles module.pyw if it exists and nothing else
1164 relevant is found.
1165
Tim Peters20f51a72001-07-21 02:31:40 +00001166
Guido van Rossum55a78992001-07-17 17:22:32 +00001167What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001168Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001169===========================
1170
1171Core
Tim Petersa814db52001-05-14 07:05:58 +00001172
Tim Peters6d6c1a32001-08-02 04:15:00 +00001173- TENTATIVELY, a large amount of code implementing much of what's
1174 described in PEP 252 (Making Types Look More Like Classes) and PEP
1175 253 (Subtyping Built-in Types) was added. This will be released
1176 with Python 2.2a1. Documentation will be provided separately
1177 through http://www.python.org/2.2/. The purpose of releasing this
1178 with Python 2.2a1 is to test backwards compatibility. It is
1179 possible, though not likely, that a decision is made not to release
1180 this code as part of 2.2 final, if any serious backwards
1181 incompapatibilities are found during alpha testing that cannot be
1182 repaired.
1183
Guido van Rossum55a78992001-07-17 17:22:32 +00001184- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001185 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001186 more 'yield' statements. See PEP 255. Since this adds a new
1187 keyword to the language, this feature must be enabled by including a
1188 future statement: "from __future__ import generators" (see PEP 236).
1189 Generators will become a standard feature in a future release
1190 (probably 2.3). Without this future statement, 'yield' remains an
1191 ordinary identifier, but a warning is issued each time it is used.
1192 (These warnings currently don't conform to the warnings framework of
1193 PEP 230; we intend to fix this in 2.2a2.)
1194
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001195- The UTF-16 codec was modified to be more RFC compliant. It will now
1196 only remove BOM characters at the start of the string and then
1197 only if running in native mode (UTF-16-LE and -BE won't remove a
1198 leading BMO character).
1199
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001200- Strings now have a new method .decode() to complement the already
1201 existing .encode() method. These two methods provide direct access
1202 to the corresponding decoders and encoders of the registered codecs.
1203
1204 To enhance the usability of the .encode() method, the special
1205 casing of Unicode object return values was dropped (Unicode objects
1206 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001207
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001208 Both methods will now return whatever the codec in charge of the
1209 requested encoding returns as object, e.g. Unicode codecs will
1210 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1211 will return u"äöü"). This enables codec writer to create codecs
1212 for various simple to use conversions.
1213
1214 New codecs were added to demonstrate these new features (the .encode()
1215 and .decode() columns indicate the type of the returned objects):
1216
1217 Name | .encode() | .decode() | Description
1218 ----------------------------------------------------------------------
1219 uu | string | string | UU codec (e.g. for email)
1220 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001221 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001222 zlib | string | string | zlib compression
1223 hex | string | string | 2-byte hex codec
1224 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1225
Mark Hammond2a0af792001-05-14 03:09:36 +00001226- Some operating systems now support the concept of a default Unicode
1227 encoding for file system operations. Notably, Windows supports 'mbcs'
1228 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001229 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001230 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001231
1232 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001233 functions that return filenames (such as os.listdir()) to return Python
1234 string objects pre-encoded using the default file system encoding for
1235 the platform. As this encoding is likely to be different from Python's
1236 default encoding, converting this name to a Unicode object before passing
1237 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001238 would attempt to use its default encoding (generally ASCII) rather than
1239 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001240
Tim Petersa814db52001-05-14 07:05:58 +00001241 In general, this change simply removes surprises when working with
1242 Unicode and the file system, making these operations work as you expect,
1243 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001244 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001245
Tim Peters61dff2b2001-05-08 15:43:37 +00001246- Float (and complex) literals in source code were evaluated to full
1247 precision only when running from a .py file; the same code loaded from a
1248 .pyc (or .pyo) file could suffer numeric differences starting at about the
1249 12th significant decimal digit. For example, on a machine with IEEE-754
1250 floating arithmetic,
1251
1252 x = 9007199254740992.0
1253 print long(x)
1254
1255 printed 9007199254740992 if run directly from .py, but 9007199254740000
1256 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1257 str(float) instead of repr(float) when building code objects. marshal
1258 now uses repr(float) instead, which should reproduce floats to full
1259 machine precision (assuming the platform C float<->string I/O conversion
1260 functions are of good quality).
1261
1262 This may cause floating-point results to change in some cases, and
1263 usually for the better, but may also cause numerically unstable
1264 algorithms to break.
1265
Tim Peters2f228e72001-05-13 00:19:31 +00001266- The implementation of dicts suffers fewer collisions, which has speed
1267 benefits. However, the order in which dict entries appear in dict.keys(),
1268 dict.values() and dict.items() may differ from previous releases for a
1269 given dict. Nothing is defined about this order, so no program should
1270 rely on it. Nevertheless, it's easy to write test cases that rely on the
1271 order by accident, typically because of printing the str() or repr() of a
1272 dict to an "expected results" file. See Lib/test/test_support.py's new
1273 sortdict(dict) function for a simple way to display a dict in sorted
1274 order.
1275
Tim Peters7a3bfc32001-06-12 01:22:22 +00001276- Many other small changes to dicts were made, resulting in faster
1277 operation along the most common code paths.
1278
Guido van Rossum10315822001-05-01 20:54:30 +00001279- Dictionary objects now support the "in" operator: "x in dict" means
1280 the same as dict.has_key(x).
1281
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001282- The update() method of dictionaries now accepts generic mapping
1283 objects. Specifically the argument object must support the .keys()
1284 and __getitem__() methods. This allows you to say, for example,
1285 {}.update(UserDict())
1286
Guido van Rossum10315822001-05-01 20:54:30 +00001287- Iterators were added; this is a generalized way of providing values
1288 to a for loop. See PEP 234. There's a new built-in function iter()
1289 to return an iterator. There's a new protocol to get the next value
1290 from an iterator using the next() method (in Python) or the
1291 tp_iternext slot (in C). There's a new protocol to get iterators
1292 using the __iter__() method (in Python) or the tp_iter slot (in C).
1293 Iterating (i.e. a for loop) over a dictionary generates its keys.
1294 Iterating over a file generates its lines.
1295
Tim Petersf553f892001-05-01 20:45:31 +00001296- The following functions were generalized to work nicely with iterator
1297 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001298 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001299 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1300 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001301 join() method of strings
1302 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001303 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1304 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001305 right-hand side of assignment statements with multiple targets, such as
1306 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001307
Tim Petersd85e1022001-05-11 21:51:48 +00001308- Accessing module attributes is significantly faster (for example,
1309 random.random or os.path or yourPythonModule.yourAttribute).
1310
Tim Peterse63415e2001-05-08 04:38:29 +00001311- Comparing dictionary objects via == and != is faster, and now works even
1312 if the keys and values don't support comparisons other than ==.
1313
Tim Peters95bf9392001-05-10 08:32:44 +00001314- Comparing dictionaries in ways other than == and != is slower: there were
1315 insecurities in the dict comparison implementation that could cause Python
1316 to crash if the element comparison routines for the dict keys and/or
1317 values mutated the dicts. Making the code bulletproof slowed it down.
1318
Tim Peterseb28ef22001-06-02 05:27:19 +00001319- Collisions in dicts are resolved via a new approach, which can help
1320 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001321 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001322 faster now. Thanks to Christian Tismer for pointing out the cause and
1323 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001324
Tim Peters52e155e2001-06-16 05:42:57 +00001325- repr() is much faster for large containers (dict, list, tuple).
1326
1327
Tim Petersa814db52001-05-14 07:05:58 +00001328Library
1329
Fred Drake960fdf92001-07-20 18:38:26 +00001330- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1331 were added to the string module. These a locale-indenpendent
1332 constants, unlike letters, lowercase, and uppercase. These are now
1333 use in appropriate locations in the standard library.
1334
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001335- The flags used in dlopen calls can now be configured using
1336 sys.setdlopenflags and queried using sys.getdlopenflags.
1337
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001338- Fredrik Lundh's xmlrpclib is now a standard library module. This
1339 provides full client-side XML-RPC support. In addition,
1340 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1341 one asyncore-based). Thanks to Eric Raymond for the documentation.
1342
Guido van Rossum643d3912001-07-05 14:46:25 +00001343- The xrange() object is simplified: it no longer supports slicing,
1344 repetition, comparisons, efficient 'in' checking, the tolist()
1345 method, or the start, stop and step attributes. See PEP 260.
1346
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001347- A new function fnmatch.filter to filter lists of file names was added.
1348
Barry Warsawffd674d2001-05-22 16:00:10 +00001349- calendar.py uses month and day names based on the current locale.
1350
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001351- strop is now *really* obsolete (this was announced before with 1.6),
1352 and issues DeprecationWarning when used (except for the four items
1353 that are still imported into string.py).
1354
Tim Petersa814db52001-05-14 07:05:58 +00001355- Cookie.py now sorts key+value pairs by key in output strings.
1356
1357- pprint.isrecursive(object) didn't correctly identify recursive objects.
1358 Now it does.
1359
Tim Peters95b3f782001-05-14 18:39:41 +00001360- pprint functions now much faster for large containers (tuple, list, dict).
1361
Tim Peters7b9542a2001-06-10 23:40:19 +00001362- New 'q' and 'Q' format codes in the struct module, corresponding to C
1363 types "long long" and "unsigned long long" (on Windows, __int64). In
1364 native mode, these can be used only when the platform C compiler supports
1365 these types (when HAVE_LONG_LONG is #define'd by the Python config
1366 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001367 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1368 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001369
Guido van Rossum83213cc2001-06-12 16:48:52 +00001370- The site module installs a new built-in function 'help' that invokes
1371 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1372 it displays a message reminding the user to use 'help()' or
1373 'help(object)'.
1374
Tim Petersa814db52001-05-14 07:05:58 +00001375Tests
1376
1377- New test_mutants.py runs dict comparisons where the key and value
1378 comparison operators mutute the dicts randomly during comparison. This
1379 rapidly causes Python to crash under earlier releases (not for the faint
1380 of heart: it can also cause Win9x to freeze or reboot!).
1381
1382- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001383 pprint.isreadable() return sensible results. Also verifies that simple
1384 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001385
Tim Peters4324aa32001-05-28 22:30:08 +00001386C API
1387
1388- Removed the unused last_is_sticky argument from the internal
1389 _PyTuple_Resize(). If this affects you, you were cheating.
1390
1391
Guido van Rossum55a78992001-07-17 17:22:32 +00001392======================================================================
1393
1394
Guido van Rossumffe13be2001-04-16 18:46:45 +00001395What's New in Python 2.1 (final)?
1396=================================
1397
1398We only changed a few things since the last release candidate, all in
1399Python library code:
1400
1401- A bug in the locale module was fixed that affected locales which
1402 define no grouping for numeric formatting.
1403
1404- A few bugs in the weakref module's implementations of weak
1405 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1406 and the test suite was updated to check for these bugs.
1407
1408- An old bug in the os.path.walk() function (introduced in Python
1409 2.0!) was fixed: a non-existent file would cause an exception
1410 instead of being ignored.
1411
1412- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1413 PyChecker.
1414
1415
Guido van Rossum5b08f132001-04-16 02:05:23 +00001416What's New in Python 2.1c2?
1417===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001418
Guido van Rossum5b08f132001-04-16 02:05:23 +00001419A flurry of small changes, and one showstopper fixed in the nick of
1420time made it necessary to release another release candidate. The list
1421here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001422
Guido van Rossum5b08f132001-04-16 02:05:23 +00001423Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001424
Guido van Rossum5b08f132001-04-16 02:05:23 +00001425- Tim discovered a nasty bug in the dictionary code, caused by
1426 PyDict_Next() calling dict_resize(), and the GC code's use of
1427 PyDict_Next() violating an assumption in dict_items(). This was
1428 fixed with considerable amounts of band-aid, but the net effect is a
1429 saner and more robust implementation.
1430
1431- Made a bunch of symbols static that were accidentally global.
1432
1433Build and Ports
1434
1435- The setup.py script didn't check for a new enough version of zlib
1436 (1.1.3 is needed). Now it does.
1437
1438- Changed "make clean" target to also remove shared libraries.
1439
1440- Added a more general warning about the SGI Irix optimizer to README.
1441
1442Library
1443
1444- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1445 omitted the slash between host and file.html.
1446
1447- The mailbox module's _Mailbox class contained a completely broken
1448 and undocumented seek() method. Ripped it out.
1449
1450- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1451 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1452
1453- Fixed a few last-minute bugs in unittest.
1454
1455Extensions
1456
1457- Reverted the patch to the OpenSSL code in socketmodule.c to support
1458 RAND_status() and the EGD, and the subsequent patch that tried to
1459 fix it for pre-0.9.5 versions; the problem with the patch is that on
1460 some systems it issues a warning whenever socket is imported, and
1461 that's unacceptable.
1462
1463Tests
1464
1465- Fixed the pickle tests to work with "import test.test_pickle".
1466
1467- Tweaked test_locale.py to actually run the test Windows.
1468
1469- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1470 not "wb" (which is not a valid mode at all).
1471
1472- Fix pstats browser crashes. Import readline if it exists to make
1473 the user interface nicer.
1474
1475- Add "import thread" to the top of test modules that import the
1476 threading module (test_asynchat and test_threadedtempfile). This
1477 prevents test failures caused by a broken threading module resulting
1478 from a previously caught failed import.
1479
1480- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1481 needed on some platforms (e.g. Solaris 8) when the tests are run
1482 twice in succession.
1483
1484- Skip rather than fail test_sunaudiodev if no audio device is found.
1485
1486
1487What's New in Python 2.1c1?
1488===========================
1489
1490This list was significantly updated when 2.1c2 was released; the 2.1c1
1491release didn't mention most changes that were actually part of 2.1c1:
1492
1493Legal
1494
1495- Copyright was assigned to the Python Software Foundation (PSF) and a
1496 PSF license (very similar to the CNRI license) was added.
1497
1498- The CNRI copyright notice was updated to include 2001.
1499
1500Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001501
Guido van Rossumc9932722001-04-12 02:31:27 +00001502- After a public outcry, assignment to __debug__ is no longer illegal;
1503 instead, a warning is issued. It will become illegal in 2.2.
1504
Guido van Rossum5b08f132001-04-16 02:05:23 +00001505- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1506 "%#x" now always prepends "0x", even if the value is zero.
1507
1508- Fixed some nits in the bytecode compiler.
1509
1510- Fixed core dumps when calling certain kinds of non-functions.
1511
1512- Fixed various core dumps caused by reference count bugs.
1513
1514Build and Ports
1515
1516- Use INSTALL_SCRIPT to install script files.
1517
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001518- New port: SCO Unixware 7, by Billy G. Allie.
1519
Guido van Rossum5b08f132001-04-16 02:05:23 +00001520- Updated RISCOS port.
1521
1522- Updated BeOS port and notes.
1523
1524- Various other porting problems resolved.
1525
1526Library
1527
1528- The TERMIOS and SOCKET modules are now truly obsolete and
1529 unnecessary. Their symbols are incorporated in the termios and
1530 socket modules.
1531
1532- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1533 better tests for pickling.
1534
1535- threading: make Condition.wait() robust against KeyboardInterrupt.
1536
1537- zipfile: add support to zipfile to support opening an archive
1538 represented by an open file rather than a file name. Fix bug where
1539 the archive was not properly closed. Fixed a bug in this bugfix
1540 where flush() was called for a read-only file.
1541
1542- imputil: added an uninstall() method to the ImportManager.
1543
1544- Canvas: fixed bugs in lower() and tkraise() methods.
1545
1546- SocketServer: API change (added overridable close_request() method)
1547 so that the TCP server can explicitly close the request.
1548
1549- pstats: Eric Raymond added a simple interactive statistics browser,
1550 invoked when the module is run as a script.
1551
1552- locale: fixed a problem in format().
1553
1554- webbrowser: made it work when the BROWSER environment variable has a
1555 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1556 KDE 2. Fixed some other nits.
1557
1558- unittest: changes to allow using a different exception than
1559 AssertionError, and added a few more function aliases. Some other
1560 small changes.
1561
1562- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1563
1564- asynchat: fixed a critical bug in asynchat that slipped through the
1565 2.1b2 release. Fixed another rare bug.
1566
1567- Fix some unqualified except: clauses (always a bad code example).
1568
1569XML
1570
1571- pyexpat: new API get_version_string().
1572
1573- Fixed some minidom bugs.
1574
1575Extensions
1576
1577- Fixed a core dump in _weakref. Removed the weakref.mapping()
1578 function (it adds nothing to the API).
1579
1580- Rationalized the use of header files in the readline module, to make
1581 it compile (albeit with some warnings) with the very recent readline
1582 4.2, without breaking for earlier versions.
1583
1584- Hopefully fixed a buffering problem in linuxaudiodev.
1585
1586- Attempted a fix to make the OpenSSL support in the socket module
1587 work again with pre-0.9.5 versions of OpenSSL.
1588
1589Tests
1590
1591- Added a test case for asynchat and asyncore.
1592
1593- Removed coupling between tests where one test failing could break
1594 another.
1595
1596Tools
1597
1598- Ping added an interactive help browser to pydoc, fixed some nits
1599 in the rest of the pydoc code, and added some features to his
1600 inspect module.
1601
1602- An updated python-mode.el version 4.1 which integrates Ken
1603 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1604 much nicer in XEmacs and Emacs. When stepping through your program
1605 with pdb, in either the shell window or the *Python* window, the
1606 source file and line will be tracked by an arrow. Very cool!
1607
1608- IDLE: syntax warnings in interactive mode are changed into errors.
1609
1610- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001611 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001612
1613- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001614
Barry Warsaw11e89c72001-04-11 20:37:57 +00001615
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001616What's New in Python 2.1 beta 2?
1617================================
1618
Guido van Rossum053ae352001-03-22 14:17:21 +00001619(Unlisted are many fixed bugs, more documentation, etc.)
1620
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001621Core language, builtins, and interpreter
1622
Guido van Rossum053ae352001-03-22 14:17:21 +00001623- The nested scopes work (enabled by "from __future__ import
1624 nested_scopes") is completed; in particular, the future now extends
1625 into code executed through exec, eval() and execfile(), and into the
1626 interactive interpreter.
1627
1628- When calling a base class method (e.g. BaseClass.__init__(self)),
1629 this is now allowed even if self is not strictly spoken a class
1630 instance (e.g. when using metaclasses or the Don Beaudry hook).
1631
1632- Slice objects are now comparable but not hashable; this prevents
1633 dict[:] from being accepted but meaningless.
1634
1635- Complex division is now calculated using less braindead algorithms.
1636 This doesn't change semantics except it's more likely to give useful
1637 results in extreme cases. Complex repr() now uses full precision
1638 like float repr().
1639
1640- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1641
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001642- It is illegal to assign to the name __debug__, which is set when the
1643 interpreter starts. It is effectively a compile-time constant.
1644
1645- A warning will be issued if a global statement for a variable
1646 follows a use or assignment of that variable.
1647
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001648Standard library
1649
Guido van Rossum053ae352001-03-22 14:17:21 +00001650- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1651 inspired by JUnit), is now part of the standard library. You now
1652 have a choice of two testing frameworks: unittest requires you to
1653 write testcases as separate code, doctest gathers them from
1654 docstrings. Both approaches have their advantages and
1655 disadvantages.
1656
1657- A new module Tix was added, which wraps the Tix extension library
1658 for Tk. With that module, it is not necessary to statically link
1659 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1660 require" command. See Demo/tix/.
1661
1662- tzparse.py is now obsolete.
1663
1664- In gzip.py, the seek() and tell() methods are removed -- they were
1665 non-functional anyway, and it's better if callers can test for their
1666 existence with hasattr().
1667
1668Python/C API
1669
1670- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1671 that's already in the dictionary during a PyDict_Next() iteration.
1672 This used to fail occasionally when a dictionary resize operation
1673 could be triggered that would rehash all the keys. All other
1674 modifications to the dictionary are still off-limits during a
1675 PyDict_Next() iteration!
1676
1677- New extended APIs related to passing compiler variables around.
1678
1679- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1680 implement isinstance() and issubclass().
1681
1682- Py_BuildValue() now has a "D" conversion to create a Python complex
1683 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001684
Fred Drake4e262a92001-03-22 18:26:47 +00001685- Extensions types which support weak references must now set the
1686 field allocated for the weak reference machinery to NULL themselves;
1687 this is done to avoid the cost of checking each object for having a
1688 weakly referencable type in PyObject_INIT(), since most types are
1689 not weakly referencable.
1690
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001691- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1692 free variables and cell variables to and from the frame's f_locals.
1693
1694- Variants of several functions defined in pythonrun.h have been added
1695 to support the nested_scopes future statement. The variants all end
1696 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1697 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1698 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001699 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001700
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001701Distutils
1702
1703- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1704 into the release tree.
1705
Tim Peters0e57abf2001-05-02 07:39:38 +00001706- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001707 (an uninstaller, more customization of the installer's display)
1708
1709- from Jack Jansen: added Mac-specific code to generate a dialog for
1710 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001711 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001712 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001713
1714- added 'platforms' and 'keywords' to the set of metadata that can be
1715 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001716
1717- applied patches from Jason Tishler to make the compiler class work with
1718 Cygwin.
1719
1720
Tim Peters2fe289a2001-03-01 22:19:38 +00001721What's New in Python 2.1 beta 1?
1722================================
Tim Petersd66595f2001-02-04 03:09:53 +00001723
1724Core language, builtins, and interpreter
1725
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001726- Following an outcry from the community about the amount of code
1727 broken by the nested scopes feature introduced in 2.1a2, we decided
1728 to make this feature optional, and to wait until Python 2.2 (or at
1729 least 6 months) to make it standard. The option can be enabled on a
1730 per-module basis by adding "from __future__ import nested_scopes" at
1731 the beginning of a module (before any other statements, but after
1732 comments and an optional docstring). See PEP 236 (Back to the
1733 __future__) for a description of the __future__ statement. PEP 227
1734 (Statically Nested Scopes) has been updated to reflect this change,
1735 and to clarify the semantics in a number of endcases.
1736
1737- The nested scopes code, when enabled, has been hardened, and most
1738 bugs and memory leaks in it have been fixed.
1739
1740- Compile-time warnings are now generated for a number of conditions
1741 that will break or change in meaning when nested scopes are enabled:
1742
1743 - Using "from...import *" or "exec" without in-clause in a function
1744 scope that also defines a lambda or nested function with one or
1745 more free (non-local) variables. The presence of the import* or
1746 bare exec makes it impossible for the compiler to determine the
1747 exact set of local variables in the outer scope, which makes it
1748 impossible to determine the bindings for free variables in the
1749 inner scope. To avoid the warning about import *, change it into
1750 an import of explicitly name object, or move the import* statement
1751 to the global scope; to avoid the warning about bare exec, use
1752 exec...in... (a good idea anyway -- there's a possibility that
1753 bare exec will be deprecated in the future).
1754
1755 - Use of a global variable in a nested scope with the same name as a
1756 local variable in a surrounding scope. This will change in
1757 meaning with nested scopes: the name in the inner scope will
1758 reference the variable in the outer scope rather than the global
1759 of the same name. To avoid the warning, either rename the outer
1760 variable, or use a global statement in the inner function.
1761
Neil Schemenauera35c6882001-02-27 04:45:05 +00001762- An optional object allocator has been included. This allocator is
1763 optimized for Python objects and should be faster and use less memory
1764 than the standard system allocator. It is not enabled by default
1765 because of possible thread safety problems. The allocator is only
1766 protected by the Python interpreter lock and it is possible that some
1767 extension modules require a thread safe allocator. The object
1768 allocator can be enabled by providing the "--with-pymalloc" option to
1769 configure.
1770
Tim Petersd66595f2001-02-04 03:09:53 +00001771Standard library
1772
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001773- pyexpat now detects the expat version if expat.h defines it. A
1774 number of additional handlers are provided, which are only available
1775 since expat 1.95. In addition, the methods SetParamEntityParsing and
1776 GetInputContext of Parser objects are available with 1.95.x
1777 only. Parser objects now provide the ordered_attributes and
1778 specified_attributes attributes. A new module expat.model was added,
1779 which offers a number of additional constants if 1.95.x is used.
1780
1781- xml.dom offers the new functions registerDOMImplementation and
1782 getDOMImplementation.
1783
1784- xml.dom.minidom offers a toprettyxml method. A number of DOM
1785 conformance issues have been resolved. In particular, Element now
1786 has an hasAttributes method, and the handling of namespaces was
1787 improved.
1788
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001789- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1790 getting information about live Python code, and pydoc.py, a module
1791 for interactively converting docstrings to HTML or text.
1792 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001793 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001794 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1795 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001796
Tim Peters1eff7962001-03-01 02:31:33 +00001797- New library module difflib.py, primarily packaging the SequenceMatcher
1798 class at the heart of the popular ndiff.py file-comparison tool.
1799
1800- doctest.py (a framework for verifying Python code examples in docstrings)
1801 is now part of the std library.
1802
Tim Petersd66595f2001-02-04 03:09:53 +00001803Windows changes
1804
Guido van Rossume3955a82001-03-02 14:05:59 +00001805- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1806 small GUI that lets you browse the module docstrings using your
1807 default web browser.
1808
Tim Peters1eff7962001-03-01 02:31:33 +00001809- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1810 Platforms) is implemented. See
1811
1812 http://python.sourceforge.net/peps/pep-0235.html
1813
1814 for full details, especially the "Current Lower-Left Semantics" section.
1815 The new Windows import rules are simpler than before:
1816
1817 A. If the PYTHONCASEOK environment variable exists, same as
1818 before: silently accept the first case-insensitive match of any
1819 kind; raise ImportError if none found.
1820
1821 B. Else search sys.path for the first case-sensitive match; raise
1822 ImportError if none found.
1823
1824 The same rules have been implented on other platforms with case-
1825 insensitive but case-preserving filesystems too (including Cygwin, and
1826 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001827
Tim Peters25a9ce32001-02-19 07:06:36 +00001828- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1829 what it's supposed to do (and does do under NT and 2000) via direct
1830 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001831 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001832 all Win9x systems before.
1833
Tim Peters1eff7962001-03-01 02:31:33 +00001834- Build: Subproject _test (effectively) renamed to _testcapi.
1835
Tim Peters2fe289a2001-03-01 22:19:38 +00001836New platforms
1837
1838- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1839 Thanks to Steven Majewski!
1840
1841- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1842 Tishler!
1843
Guido van Rossum9089b272001-03-02 06:49:50 +00001844- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1845 Schwertberger! See RISCOS/README for more information -- it seems
1846 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001847 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001848
Tim Peters25a9ce32001-02-19 07:06:36 +00001849
Tim Petersd7b5e882001-01-25 03:36:26 +00001850What's New in Python 2.1 alpha 2?
1851=================================
Tim Peters40ead762001-01-27 05:35:26 +00001852
Tim Petersd7b5e882001-01-25 03:36:26 +00001853Core language, builtins, and interpreter
1854
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001855- Scopes nest. If a name is used in a function or class, but is not
1856 local, the definition in the nearest enclosing function scope will
1857 be used. One consequence of this change is that lambda statements
1858 could reference variables in the namespaces where the lambda is
1859 defined. In some unusual cases, this change will break code.
1860
1861 In all previous version of Python, names were resolved in exactly
1862 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001863 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001864 function A is defined within a function B, the names bound in B are
1865 not visible in A. The new rules make names bound in B visible in A,
1866 unless A contains a name binding that hides the binding in B.
1867
1868 Section 4.1 of the reference manual describes the new scoping rules
1869 in detail. The test script in Lib/test/test_scope.py demonstrates
1870 some of the effects of the change.
1871
1872 The new rules will cause existing code to break if it defines nested
1873 functions where an outer function has local variables with the same
1874 name as globals or builtins used by the inner function. Example:
1875
1876 def munge(str):
1877 def helper(x):
1878 return str(x)
1879 if type(str) != type(''):
1880 str = helper(str)
1881 return str.strip()
1882
1883 Under the old rules, the name str in helper() is bound to the
1884 builtin function str(). Under the new rules, it will be bound to
1885 the argument named str and an error will occur when helper() is
1886 called.
1887
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001888- The compiler will report a SyntaxError if "from ... import *" occurs
1889 in a function or class scope. The language reference has documented
1890 that this case is illegal, but the compiler never checked for it.
1891 The recent introduction of nested scope makes the meaning of this
1892 form of name binding ambiguous. In a future release, the compiler
1893 may allow this form when there is no possibility of ambiguity.
1894
Tim Peters40ead762001-01-27 05:35:26 +00001895- repr(string) is easier to read, now using hex escapes instead of octal,
1896 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1897
1898 >>> "\texample \r\n" + chr(0) + chr(255)
1899 '\texample \r\n\x00\xff' # in 2.1
1900 '\011example \015\012\000\377' # in 2.0
1901
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001902- Functions are now compared and hashed by identity, not by value, since
1903 the func_code attribute is writable.
1904
Fred Drakefb9d7122001-02-01 20:00:40 +00001905- Weak references (PEP 205) have been added. This involves a few
1906 changes in the core, an extension module (_weakref), and a Python
1907 module (weakref). The weakref module is the public interface. It
1908 includes support for "explicit" weak references, proxy objects, and
1909 mappings with weakly held values.
1910
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001911- A 'continue' statement can now appear in a try block within the body
1912 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001913 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001914
Tim Petersd7b5e882001-01-25 03:36:26 +00001915Standard library
1916
Barry Warsaw30dbd142001-01-31 22:14:01 +00001917- mailbox.py now has a new class, PortableUnixMailbox which is
1918 identical to UnixMailbox but uses a more portable scheme for
1919 determining From_ separators. Also, the constructors for all the
1920 classes in this module have a new optional `factory' argument, which
1921 is a callable used when new message classes must be instantiated by
1922 the next() method.
1923
Tim Petersd7b5e882001-01-25 03:36:26 +00001924- random.py is now self-contained, and offers all the functionality of
1925 the now-deprecated whrandom.py. See the docs for details. random.py
1926 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001927 and restoring the internal state of the generator; and jumpahead(n),
1928 for quickly forcing the internal state to be the same as if n calls to
1929 random() had been made. The latter is particularly useful for multi-
1930 threaded programs, creating one instance of the random.Random() class for
1931 each thread, then using .jumpahead() to force each instance to use a
1932 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001933
Tim Peters0de88fc2001-02-01 04:59:18 +00001934- random.py's seed() function is new. For bit-for-bit compatibility with
1935 prior releases, use the whseed function instead. The new seed function
1936 addresses two problems: (1) The old function couldn't produce more than
1937 about 2**24 distinct internal states; the new one about 2**45 (the best
1938 that can be done in the Wichmann-Hill generator). (2) The old function
1939 sometimes produced identical internal states when passed distinct
1940 integers, and there was no simple way to predict when that would happen;
1941 the new one guarantees to produce distinct internal states for all
1942 arguments in [0, 27814431486576L).
1943
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001944- The socket module now supports raw packets on Linux. The socket
1945 family is AF_PACKET.
1946
Tim Peters9ea17ac2001-02-02 05:57:15 +00001947- test_capi.py is a start at running tests of the Python C API. The tests
1948 are implemented by the new Modules/_testmodule.c.
1949
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001950- A new extension module, _symtable, provides provisional access to the
1951 internal symbol table used by the Python compiler. A higher-level
1952 interface will be added on top of _symtable in a future release.
1953
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001954- Removed the obsolete soundex module.
1955
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001956- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1957 the isSameNode method; NamedNodeMap the get method.
1958
1959- xml.sax.expatreader supports the lexical handler property; it
1960 generates comment, startCDATA, and endCDATA events.
1961
Tim Petersee826f82001-01-31 19:39:44 +00001962Windows changes
1963
1964- Build procedure: the zlib project is built in a different way that
1965 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001966 the zlib binary used. See PCbuild\readme.txt for details. Your old
1967 zlib-related directories can be deleted; you'll need to download fresh
1968 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001969
Tim Peters9ea17ac2001-02-02 05:57:15 +00001970- Build: New subproject _test for the benefit of test_capi.py (see above).
1971
Tim Petersb16c56f2001-02-02 21:24:51 +00001972- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1973 interface to some Python compiler internals).
1974
1975- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001976 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001977
Tim Petersa3a3a032000-11-30 05:22:44 +00001978What's New in Python 2.1 alpha 1?
1979=================================
1980
1981Core language, builtins, and interpreter
1982
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001983- There is a new Unicode companion to the PyObject_Str() API
1984 called PyObject_Unicode(). It behaves in the same way as the
1985 former, but assures that the returned value is an Unicode object
1986 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001987
Guido van Rossumf98eda02001-01-17 15:54:45 +00001988- The comparison operators support "rich comparison overloading" (PEP
1989 207). C extension types can provide a rich comparison function in
1990 the new tp_richcompare slot in the type object. The cmp() function
1991 and the C function PyObject_Compare() first try the new rich
1992 comparison operators before trying the old 3-way comparison. There
1993 is also a new C API PyObject_RichCompare() (which also falls back on
1994 the old 3-way comparison, but does not constrain the outcome of the
1995 rich comparison to a Boolean result).
1996
1997 The rich comparison function takes two objects (at least one of
1998 which is guaranteed to have the type that provided the function) and
1999 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2000 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2001 object, which may be NotImplemented (in which case the tp_compare
2002 slot function is used as a fallback, if defined).
2003
2004 Classes can overload individual comparison operators by defining one
2005 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002006 __ge__. There are no explicit "reflected argument" versions of
2007 these; instead, __lt__ and __gt__ are each other's reflection,
2008 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2009 reflection (similar at the C level). No other implications are
2010 made; in particular, Python does not assume that == is the Boolean
2011 inverse of !=, or that < is the Boolean inverse of >=. This makes
2012 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002013
2014 Classes or types that want to implement (in)equality tests but not
2015 the ordering operators (i.e. unordered types) should implement ==
2016 and !=, and raise an error for the ordering operators.
2017
Guido van Rossuma88479f2001-01-18 14:28:08 +00002018 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002019 Boolean; e.g. a matrix type might want to return a matrix of bits
2020 for A < B, giving elementwise comparisons. Such types should ensure
2021 that any interpretation of their value in a Boolean context raises
2022 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2023 at the C level) to always raise an exception.
2024
Guido van Rossuma88479f2001-01-18 14:28:08 +00002025- Complex numbers use rich comparisons to define == and != but raise
2026 an exception for <, <=, > and >=. Unfortunately, this also means
2027 that cmp() of two complex numbers raises an exception when the two
2028 numbers differ. Since it is not mathematically meaningful to compare
2029 complex numbers except for equality, I hope that this doesn't break
2030 too much code.
2031
Tim Peters3389f192001-02-18 08:48:49 +00002032- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002033 not defined by the language, other than that it's arbitrary but
2034 consistent (see the Reference Manual). An implementation detail changed
2035 in 2.1a1 such that None now compares less than any other object. Code
2036 relying on this new behavior (like code that relied on the previous
2037 behavior) does so at its own risk.
2038
Barry Warsaw573b5412001-01-15 20:43:18 +00002039- Functions and methods now support getting and setting arbitrarily
2040 named attributes (PEP 232). Functions have a new __dict__
2041 (a.k.a. func_dict) which hold the function attributes. Methods get
2042 and set attributes on their underlying im_func. It is a TypeError
2043 to set an attribute on a bound method.
2044
Guido van Rossum051e3352001-01-15 19:11:10 +00002045- The xrange() object implementation has been improved so that
2046 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2047 limitation that in this case len(xrange(sys.maxint)) can't be
2048 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2049 work fine as long as the index i doesn't actually reach 2**31.
2050 (Python uses regular ints for sequence and string indices; fixing
2051 that is much more work.)
2052
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002053- Two changes to from...import:
2054
Guido van Rossumba381232001-02-03 15:06:40 +00002055 1) "from M import X" now works even if (after loading module M)
2056 sys.modules['M'] is not a real module; it's basically a getattr()
2057 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002058
2059 2) "from M import *" now looks for M.__all__ to decide which names to
2060 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2061 filters out names starting with '_' as before. Whether or not
2062 __all__ exists, there's no restriction on the type of M.
2063
Guido van Rossumf61f1662001-01-10 20:13:55 +00002064- File objects have a new method, xreadlines(). This is the fastest
2065 way to iterate over all lines in a file:
2066
2067 for line in file.xreadlines():
2068 ...do something to line...
2069
2070 See the xreadlines module (mentioned below) for how to do this for
2071 other file-like objects.
2072
2073- Even if you don't use file.xreadlines(), you may expect a speedup on
2074 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002075 quite a bit in platform-specific ways: on systems (like Linux) that
2076 support flockfile(), getc_unlocked(), and funlockfile(), those are
2077 used by default. On systems (like Windows) without getc_unlocked(),
2078 a complicated (but still thread-safe) method using fgets() is used by
2079 default.
2080
Tim Petersd52269b2001-01-25 06:23:18 +00002081 You can force use of the fgets() method by #define'ing
2082 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002083 getc_unlocked()).
2084
Tim Petersd52269b2001-01-25 06:23:18 +00002085 You can force fgets() not to be used by #define'ing
2086 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002087 test_bufio.py fails -- and let us know if it does!).
2088
2089- In addition, the fileinput module, while still slower than the other
2090 methods on most platforms, has been sped up too, by using
2091 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002092
2093- Support for run-time warnings has been added, including a new
2094 command line option (-W) to specify the disposition of warnings.
2095 See the description of the warnings module below.
2096
2097- Extensive changes have been made to the coercion code. This mostly
2098 affects extension modules (which can now implement mixed-type
2099 numerical operators without having to use coercion), but
2100 occasionally, in boundary cases the coercion semantics have changed
2101 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002102 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002103 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002104 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002105
Guido van Rossumf98eda02001-01-17 15:54:45 +00002106- In connection with the coercion changes, a new built-in singleton
2107 object, NotImplemented is defined. This can be returned for
2108 operations that wish to indicate they are not implemented for a
2109 particular combination of arguments. From C, this is
2110 Py_NotImplemented.
2111
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002112- The interpreter accepts now bytecode files on the command line even
2113 if they do not have a .pyc or .pyo extension. On Linux, after executing
2114
Martin v. Löwise214baa2001-02-04 22:37:56 +00002115import imp,sys,string
2116magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2117reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2118open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002119
2120 any byte code file can be used as an executable (i.e. as an argument
2121 to execve(2)).
2122
Tim Peters9940b802000-12-01 07:59:35 +00002123- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002124 character. In 1.6 and earlier, they never produced a sign,
2125 and raised an error if the value of the long was too large
2126 to fit in a Python int. In 2.0, they produced a sign if and
2127 only if too large to fit in an int. This was inconsistent
2128 across platforms (because the size of an int varies across
2129 platforms), and inconsistent with hex() and oct(). Example:
2130
2131 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002132 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002133 'ffffffbe' # in 2.0 and before, on 32-bit machines
2134 >>> hex(-0x42L)
2135 '-0x42L' # in all versions of Python
2136
Tim Peters9940b802000-12-01 07:59:35 +00002137 The behavior of %d formats for negative Python longs remains
2138 the same as in 2.0 (although in 1.6 and before, they raised
2139 an error if the long didn't fit in a Python int).
2140
2141 %u formats don't make sense for Python longs, but are allowed
2142 and treated the same as %d in 2.1. In 2.0, a negative long
2143 formatted via %u produced a sign if and only if too large to
2144 fit in an int. In 1.6 and earlier, a negative long formatted
2145 via %u raised an error if it was too big to fit in an int.
2146
Guido van Rossum3661d392000-12-12 22:10:31 +00002147- Dictionary objects have an odd new method, popitem(). This removes
2148 an arbitrary item from the dictionary and returns it (in the form of
2149 a (key, value) pair). This can be useful for algorithms that use a
2150 dictionary as a bag of "to do" items and repeatedly need to pick one
2151 item. Such algorithms normally end up running in quadratic time;
2152 using popitem() they can usually be made to run in linear time.
2153
Tim Peters36cdad12000-12-29 02:06:45 +00002154Standard library
2155
Thomas Woutersfe385252001-01-19 23:16:56 +00002156- In the time module, the time argument to the functions strftime,
2157 localtime, gmtime, asctime and ctime is now optional, defaulting to
2158 the current time (in the local timezone).
2159
Guido van Rossumda91f222001-01-15 16:36:08 +00002160- The ftplib module now defaults to passive mode, which is deemed a
2161 more useful default given that clients are often inside firewalls
2162 these days. Note that this could break if ftplib is used to connect
2163 to a *server* that is inside a firewall, from outside; this is
2164 expected to be a very rare situation. To fix that, you can call
2165 ftp.set_pasv(0).
2166
Martin v. Löwis10a27872001-01-13 09:54:41 +00002167- The module site now treats .pth files not only for path configuration,
2168 but also supports extensions to the initialization code: Lines starting
2169 with import are executed.
2170
Guido van Rossumf61f1662001-01-10 20:13:55 +00002171- There's a new module, warnings, which implements a mechanism for
2172 issuing and filtering warnings. There are some new built-in
2173 exceptions that serve as warning categories, and a new command line
2174 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2175 turns warnings into errors). warnings.warn(message[, category])
2176 issues a warning message; this can also be called from C as
2177 PyErr_Warn(category, message).
2178
2179- A new module xreadlines was added. This exports a single factory
2180 function, xreadlines(). The intention is that this code is the
2181 absolutely fastest way to iterate over all lines in an open
2182 file(-like) object:
2183
2184 import xreadlines
2185 for line in xreadlines.xreadlines(file):
2186 ...do something to line...
2187
2188 This is equivalent to the previous the speed record holder using
2189 file.readlines(sizehint). Note that if file is a real file object
2190 (as opposed to a file-like object), this is equivalent:
2191
2192 for line in file.xreadlines():
2193 ...do something to line...
2194
Tim Peters36cdad12000-12-29 02:06:45 +00002195- The bisect module has new functions bisect_left, insort_left,
2196 bisect_right and insort_right. The old names bisect and insort
2197 are now aliases for bisect_right and insort_right. XXX_right
2198 and XXX_left methods differ in what happens when the new element
2199 compares equal to one or more elements already in the list: the
2200 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002201 right. Code that doesn't care where equal elements end up should
2202 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002203
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002204- The new curses.panel module wraps the panel library that forms part
2205 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2206
Guido van Rossumf61f1662001-01-10 20:13:55 +00002207- The SocketServer module now sets the allow_reuse_address flag by
2208 default in the TCPServer class.
2209
2210- A new function, sys._getframe(), returns the stack frame pointer of
2211 the caller. This is intended only as a building block for
2212 higher-level mechanisms such as string interpolation.
2213
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002214- The pyexpat module supports a number of new handlers, which are
2215 available only in expat 1.2. If invocation of a callback fails, it
2216 will report an additional frame in the traceback. Parser objects
2217 participate now in garbage collection. If expat reports an unknown
2218 encoding, pyexpat will try to use a Python codec; that works only
2219 for single-byte charsets. The parser type objects is exposed as
2220 XMLParserObject.
2221
2222- xml.dom now offers standard definitions for symbolic node type and
2223 exception code constants, and a hierarchy of DOM exceptions. minidom
2224 was adjusted to use them.
2225
2226- The conformance of xml.dom.minidom to the DOM specification was
2227 improved. It detects a number of additional error cases; the
2228 previous/next relationship works even when the tree is modified;
2229 Node supports the normalize() method; NamedNodeMap, DocumentType and
2230 DOMImplementation classes were added; Element supports the
2231 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2232 method.
2233
Guido van Rossumf61f1662001-01-10 20:13:55 +00002234Build issues
2235
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002236- For Unix (and Unix-compatible) builds, configuration and building of
2237 extension modules is now greatly automated. Rather than having to
2238 edit the Modules/Setup file to indicate which modules should be
2239 built and where their include files and libraries are, a
2240 distutils-based setup.py script now takes care of building most
2241 extension modules. All extension modules built this way are built
2242 as shared libraries. Only a few modules that must be linked
2243 statically are still listed in the Setup file; you won't need to
2244 edit their configuration.
2245
2246- Python should now build out of the box on Cygwin. If it doesn't,
2247 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002248
2249- Python now always uses its own (renamed) implementation of getopt()
2250 -- there's too much variation among C library getopt()
2251 implementations.
2252
2253- C++ compilers are better supported; the CXX macro is always set to a
2254 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002255
Tim Petersd92dfe02000-12-12 01:18:41 +00002256Windows changes
2257
2258- select module: By default under Windows, a select() call
2259 can specify no more than 64 sockets. Python now boosts
2260 this Microsoft default to 512. If you need even more than
2261 that, see the MS docs (you'll need to #define FD_SETSIZE
2262 and recompile Python from source).
2263
Guido van Rossumf61f1662001-01-10 20:13:55 +00002264- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2265 subdirectory is no more!
2266
Tim Petersa3a3a032000-11-30 05:22:44 +00002267
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002268What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002269=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002270
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002271Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002272changes are in the file HISTORY. If you are making the jump directly
2273from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2274HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002275
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002276Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2277the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2278http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002279
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002280--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002281
2282======================================================================
2283
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002284What's new in 2.0 (since release candidate 1)?
2285==============================================
2286
2287Standard library
2288
2289- The copy_reg module was modified to clarify its intended use: to
2290 register pickle support for extension types, not for classes.
2291 pickle() will raise a TypeError if it is passed a class.
2292
2293- Fixed a bug in gettext's "normalize and expand" code that prevented
2294 it from finding an existing .mo file.
2295
2296- Restored support for HTTP/0.9 servers in httplib.
2297
Tim Peters989b7b92000-10-16 20:24:53 +00002298- The math module was changed to stop raising OverflowError in case of
2299 underflow, and return 0 instead in underflow cases. Whether Python
2300 used to raise OverflowError in case of underflow was platform-
2301 dependent (it did when the platform math library set errno to ERANGE
2302 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002303
2304- Fixed a bug in StringIO that occurred when the file position was not
2305 at the end of the file and write() was called with enough data to
2306 extend past the end of the file.
2307
2308- Fixed a bug that caused Tkinter error messages to get lost on
2309 Windows. The bug was fixed by replacing direct use of
2310 interp->result with Tcl_GetStringResult(interp).
2311
2312- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2313 redirect response.
2314
2315- Several changes were made to distutils: Some debugging code was
2316 removed from util. Fixed the installer used when an external zip
2317 program (like WinZip) is not found; the source code for this
2318 installer is in Misc/distutils. check_lib() was modified to behave
2319 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2320 test for whether installed modules are on sys.path was changed to
2321 use both normcase() and normpath().
2322
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002323- Several minor bugs were fixed in the xml package (the minidom,
2324 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002325
2326- The regression test driver (regrtest.py) behavior when invoked with
2327 -l changed: It now reports a count of objects that are recognized as
2328 garbage but not freed by the garbage collector.
2329
Tim Peters989b7b92000-10-16 20:24:53 +00002330- The regression test for the math module was changed to test
2331 exceptional behavior when the test is run in verbose mode. Python
2332 cannot yet guarantee consistent exception behavior across platforms,
2333 so the exception part of test_math is run only in verbose mode, and
2334 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002335
2336Internals
2337
2338- PyOS_CheckStack() has been disabled on Win64, where it caused
2339 test_sre to fail.
2340
2341Build issues
2342
2343- Changed compiler flags, so that gcc is always invoked with -Wall and
2344 -Wstrict-prototypes. Users compiling Python with GCC should see
2345 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002346 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002347 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002348
Tim Petersa3a3a032000-11-30 05:22:44 +00002349- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002350
2351Tools and other miscellany
2352
2353- The compiler in Tools/compiler was updated to support the new
2354 language features introduced in 2.0: extended print statement, list
2355 comprehensions, and augmented assignments. The new compiler should
2356 also be backwards compatible with Python 1.5.2; the compiler will
2357 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002358 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002359
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002360What's new in 2.0 release candidate 1 (since beta 2)?
2361=====================================================
2362
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002363What is release candidate 1?
2364
2365We believe that release candidate 1 will fix all known bugs that we
2366intend to fix for the 2.0 final release. This release should be a bit
2367more stable than the previous betas. We would like to see even more
2368widespread testing before the final release, so we are producing this
2369release candidate. The final release will be exactly the same unless
2370any show-stopping (or brown bag) bugs are found by testers of the
2371release candidate.
2372
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002373All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002374to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002375
2376Core language, builtins, and interpreter
2377
2378- A bug that caused crashes when __coerce__ was used with augmented
2379 assignment, e.g. +=, was fixed.
2380
2381- Raise ZeroDivisionError when raising zero to a negative number,
2382 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2383 power operator and the result of math.pow(0.0, -2.0) will vary by
2384 platform. On Linux, it raises a ValueError.
2385
2386- A bug in Unicode string interpolation was fixed that occasionally
2387 caused errors with formats including "%%". For example, the
2388 following expression "%% %s" % u"abc" no longer raises a TypeError.
2389
2390- Compilation of deeply nested expressions raises MemoryError instead
2391 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2392
2393- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2394 rendering them useless. They are now written in binary mode again.
2395
2396Standard library
2397
2398- Keyword arguments are now accepted for most pattern and match object
2399 methods in SRE, the standard regular expression engine.
2400
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002401- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002402 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002403
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002404- Several bugs in the Unicode handling and error handling in _tkinter
2405 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002406
2407- Fix memory management errors in Merge() and Tkapp_Call() routines.
2408
2409- Several changes were made to cStringIO to make it compatible with
2410 the file-like object interface and with StringIO. If operations are
2411 performed on a closed object, an exception is raised. The truncate
2412 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002413 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002414
2415- There were many changes made to the linuxaudiodev module and its
2416 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002417 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002418
2419 Note that this module is named poorly, because it should work
2420 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002421 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002422
2423 The module now raises exceptions when errors occur instead of
2424 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2425 audio) and defines a getptr() method that calls the
2426 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2427
2428- The library_version attribute, introduced in an earlier beta, was
2429 removed because it can not be supported with early versions of the C
2430 readline library, which provides no way to determine the version at
2431 compile-time.
2432
2433- The binascii module is now enabled on Win64.
2434
Tim Peters46446d62000-10-09 21:19:31 +00002435- tokenize.py no longer suffers "recursion depth" errors when parsing
2436 programs with very long string literals.
2437
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002438Internals
2439
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002440- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002441 which is called when the interpreter starts up to determine where
2442 the standard library is installed. These vulnerabilities affect all
2443 previous versions of Python and can be exploited by setting very
2444 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2445 setuid Python script, although use of the wrapper in
2446 Misc/setuid-prog.c will eliminate the vulnerability.
2447
2448- Fixed garbage collection bugs in instance creation that were
2449 triggered when errors occurred during initialization. The solution,
2450 applied in cPickle and in PyInstance_New(), is to call
2451 PyObject_GC_Init() after the initialization of the object's
2452 container attributes is complete.
2453
2454- pyexpat adds definitions of PyModule_AddStringConstant and
2455 PyModule_AddObject if the Python version is less than 2.0, which
2456 provides compatibility with PyXML on Python 1.5.2.
2457
2458- If the platform has a bogus definition for LONG_BIT (the number of
2459 bits in a long), an error will be reported at compile time.
2460
2461- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2462 collection crashes and possibly other, unreported crashes.
2463
2464- Fixed a memory leak in _PyUnicode_Fini().
2465
2466Build issues
2467
2468- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002469 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002470 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002471
2472- The mmap.PAGESIZE constant is now initialized using sysconf when
2473 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2474
2475- The md5 file should now compile on all platforms.
2476
2477- The select module now compiles on platforms that do not define
2478 POLLRDNORM and related constants.
2479
2480- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002481 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002482
Jeremy Hylton10921202000-10-09 18:34:12 +00002483- BeOS: A number of changes were made to the build and installation
2484 process. ar-fake now operates on a directory of object files.
2485 dl_export.h is gone, and its macros now appear on the mwcc command
2486 line during build on PPC BeOS.
2487
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002488- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002489 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002490
2491- Cygwin: Support for shared libraries, Tkinter, and sockets.
2492
2493- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2494
2495Tools and other miscellany
2496
2497- Removed debugging prints from main used with freeze.
2498
Tim Peters46446d62000-10-09 21:19:31 +00002499- IDLE auto-indent no longer crashes when it encounters Unicode
2500 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002501
2502What's new in 2.0 beta 2 (since beta 1)?
2503========================================
2504
2505Core language, builtins, and interpreter
2506
Tim Peters482c0212000-09-26 06:33:09 +00002507- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002508 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002509
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002510- Add -h and -V command line options to print the usage message and
2511 Python version number and exit immediately.
2512
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002513- eval() and exec accept Unicode objects as code parameters.
2514
2515- getattr() and setattr() now also accept Unicode objects for the
2516 attribute name, which are converted to strings using the default
2517 encoding before lookup.
2518
2519- Multiplication on string and Unicode now does proper bounds
2520 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2521 string is too long."
2522
2523- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002524 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002525
Jeremy Hylton1b618592000-09-26 05:32:36 +00002526
2527Standard library and extensions
2528
Guido van Rossum5b08f132001-04-16 02:05:23 +00002529- socket module: the OpenSSL code now adds support for RAND_status()
2530 and EGD (Entropy Gathering Device).
2531
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002532- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002533 argument checking; it still takes no arguments.
2534
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002535- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002536
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002537- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002538
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002539- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002540
2541- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002542 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002543
2544- copy: Copy Unicode objects atomically.
2545
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002546- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002547
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002548- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002549
Fred Drake67233bc2000-09-26 16:40:27 +00002550- dbm: Add get() and setdefault() methods to dbm object. Add constant
2551 `library' to module that names the library used. Added doc strings
2552 and method names to error messages. Uses configure to determine
2553 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2554 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002555
2556- distutils: Update to version 0.9.3.
2557
2558- dl: Add several dl.RTLD_ constants.
2559
2560- fpectl: Now supported on FreeBSD.
2561
2562- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2563 found by the collector will be saved in gc.garbage. This is useful
2564 for debugging a program that creates reference cycles.
2565
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002566- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002567 of HTTP class. Do not close socket on zero-length response. Do not
2568 crash when server sends invalid content-length header.
2569
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002570- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002571
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002572- marshal: When reading a short, sign-extend on platforms where shorts
2573 are bigger than 16 bits. When reading a long, repair the unportable
2574 sign extension that was being done for 64-bit machines. (It assumed
2575 that signed right shift sign-extends.)
2576
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002577- operator: Add contains(), invert(), __invert__() as aliases for
2578 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002579
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002580- os: Add support for popen2() and popen3() on all platforms where
2581 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002582
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002583- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002584 clicking on a file in Explorer (or passing the file name to the
2585 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002586
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002587- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002588 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002589
2590- pickle: Now raises ValueError when an invalid pickle that contains
2591 a non-string repr where a string repr was expected. This behavior
2592 matches cPickle.
2593
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002594- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002595
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002596- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002597
2598- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002599 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002600 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002601
2602- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002603 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002604
2605- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002606 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002607 few cycles during startup since the first call to
2608 setdefaultencoding() will initialize the codec registry and the
2609 encodings package.
2610
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002611- socket: Support for size hint in readlines() method of object returned
2612 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002613
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002614- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002615 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002616 is followed by whitespace.
2617
Tim Petersa3a3a032000-11-30 05:22:44 +00002618- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002619
2620- struct: Check ranges for bytes and shorts.
2621
2622- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002623 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002624
2625- Tkinter: Image objects are now guaranteed to have unique ids. Set
2626 event.delta to zero if Tk version doesn't support mousewheel.
2627 Removed some debugging prints.
2628
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002629- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002630
Fred Drake67233bc2000-09-26 16:40:27 +00002631- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002632 which works around a bug in Norton AntiVirus 2000 that leads directly
2633 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002634
2635- xml: New version detection code allows PyXML to override standard
2636 XML package if PyXML version is greater than 0.6.1.
2637
Fred Drake64bb3802000-09-26 16:21:35 +00002638- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2639 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2640 tree only for nodes which are sufficiently interesting to a specific
2641 application. Does not provide the HTML-specific extensions. Still
2642 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002643
Fred Drake64bb3802000-09-26 16:21:35 +00002644- xml.sax: SAX 2 support for Python, including all the handler
2645 interfaces needed to process XML 1.0 compliant XML. Some
2646 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002647
Fred Drake64bb3802000-09-26 16:21:35 +00002648- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2649 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002651
Jeremy Hylton1b618592000-09-26 05:32:36 +00002652C API
2653
2654- Add three new convenience functions for module initialization --
2655 PyModule_AddObject(), PyModule_AddIntConstant(), and
2656 PyModule_AddStringConstant().
2657
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002658- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002659 removed and add #error to Python.h if NULL isn't defined after
2660 #include of stdio.h.
2661
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002662- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002663 backwards compatibility (at the source level) with old extensions.
2664
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002665- A wrapper API was added for signal() and sigaction(). Instead of
2666 either function, always use PyOS_getsig() to get a signal handler
2667 and PyOS_setsig() to set one. A new convenience typedef
2668 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002669
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002670- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671 internal data buffer and size of a string object -- or the default
2672 encoded version of a Unicode object.
2673
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002674- PyString_Size() and PyString_AsString() accept Unicode objects.
2675
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002676- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002677 exists). INT_MAX and LONG_MAX will always be defined, even if
2678 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002679
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002680- PyFloat_FromString takes a second argument, pend, that was
2681 effectively useless. It is now officially useless but preserved for
2682 backwards compatibility. If the pend argument is not NULL, *pend is
2683 set to NULL.
2684
2685- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2686 for the attribute name. See note on getattr() above.
2687
2688- A few bug fixes to argument processing for Unicode.
2689 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2690 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2691 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002692 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002693
2694- Py_BuildValue accepts B format (for bgen-generated code).
2695
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002696
Jeremy Hylton1b618592000-09-26 05:32:36 +00002697Internals
2698
2699- On Unix, fix code for finding Python installation directory so that
2700 it works when argv[0] is a relative path.
2701
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002702- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002703 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002704 rather than by generating a copy of the object.
2705
Tim Peters482c0212000-09-26 06:33:09 +00002706- Several of the internal Unicode tables are much smaller now, and
2707 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002708
Jeremy Hylton97693b02000-09-26 17:42:51 +00002709- In the garbage collector: Fixed bug in collection of tuples. Fixed
2710 bug that caused some instances to be removed from the container set
2711 while they were still live. Fixed parsing in gc.set_debug() for
2712 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002713
2714- Fixed refcount problem in instance deallocation that only occurred
2715 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2716
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002717- On Windows, getpythonregpath is now protected against null data in
2718 registry key.
2719
2720- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002721 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002722
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002723
Jeremy Hylton1b618592000-09-26 05:32:36 +00002724Build and platform-specific issues
2725
2726- Better support of GNU Pth via --with-pth configure option.
2727
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002728- Python/C API now properly exposed to dynamically-loaded extension
2729 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002730
2731- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2732 Don't define MS_SYNC to be zero when it is undefined. Added missing
2733 prototypes in posixmodule.c.
2734
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002735- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002736 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002737
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002738- Fix largefile support on older NetBSD systems and OpenBSD by adding
2739 define for TELL64.
2740
2741
2742Tools and other miscellany
2743
2744- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2745
2746- freeze: The modulefinder now works with 2.0 opcodes.
2747
Tim Petersa3a3a032000-11-30 05:22:44 +00002748- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002749 Move hackery of sys.argv until after the Tk instance has been
2750 created, which allows the application-specific Tkinter
2751 initialization to be executed if present; also pass an explicit
2752 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002753
Jeremy Hylton1b618592000-09-26 05:32:36 +00002754
2755What's new in 2.0 beta 1?
2756=========================
2757
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002758Source Incompatibilities
2759------------------------
2760
2761None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2762such as single-argument append(), connect() and bind(), and changes to
2763str(long) and repr(float).
2764
2765
2766Binary Incompatibilities
2767------------------------
2768
2769- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2770with Python 2.0; these extensions will have to be rebuilt for Python
27712.0.
2772
2773- On Windows, attempting to import a third party extension built for
2774Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2775can do about this. Check your PYTHONPATH environment variable!
2776
2777- Python bytecode files (*.pyc and *.pyo) are not compatible between
2778releases.
2779
2780
2781Overview of Changes Since 1.6
2782-----------------------------
2783
2784There are many new modules (including brand new XML support through
2785the xml package, and i18n support through the gettext module); a list
2786of all new modules is included below. Lots of bugs have been fixed.
2787
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002788The process for making major new changes to the language has changed
2789since Python 1.6. Enhancements must now be documented by a Python
2790Enhancement Proposal (PEP) before they can be accepted.
2791
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002792There are several important syntax enhancements, described in more
2793detail below:
2794
2795 - Augmented assignment, e.g. x += 1
2796
2797 - List comprehensions, e.g. [x**2 for x in range(10)]
2798
2799 - Extended import statement, e.g. import Module as Name
2800
2801 - Extended print statement, e.g. print >> file, "Hello"
2802
2803Other important changes:
2804
2805 - Optional collection of cyclical garbage
2806
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002807Python Enhancement Proposal (PEP)
2808---------------------------------
2809
2810PEP stands for Python Enhancement Proposal. A PEP is a design
2811document providing information to the Python community, or describing
2812a new feature for Python. The PEP should provide a concise technical
2813specification of the feature and a rationale for the feature.
2814
2815We intend PEPs to be the primary mechanisms for proposing new
2816features, for collecting community input on an issue, and for
2817documenting the design decisions that have gone into Python. The PEP
2818author is responsible for building consensus within the community and
2819documenting dissenting opinions.
2820
2821The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002822
2823Augmented Assignment
2824--------------------
2825
2826This must have been the most-requested feature of the past years!
2827Eleven new assignment operators were added:
2828
Guido van Rossume905e952000-09-05 12:42:46 +00002829 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002830
2831For example,
2832
2833 A += B
2834
2835is similar to
2836
2837 A = A + B
2838
2839except that A is evaluated only once (relevant when A is something
2840like dict[index].attr).
2841
2842However, if A is a mutable object, A may be modified in place. Thus,
2843if A is a number or a string, A += B has the same effect as A = A+B
2844(except A is only evaluated once); but if a is a list, A += B has the
2845same effect as A.extend(B)!
2846
2847Classes and built-in object types can override the new operators in
2848order to implement the in-place behavior; the not-in-place behavior is
2849used automatically as a fallback when an object doesn't implement the
2850in-place behavior. For classes, the method name is derived from the
2851method name for the corresponding not-in-place operator by inserting
2852an 'i' in front of the name, e.g. __iadd__ implements in-place
2853__add__.
2854
2855Augmented assignment was implemented by Thomas Wouters.
2856
2857
2858List Comprehensions
2859-------------------
2860
2861This is a flexible new notation for lists whose elements are computed
2862from another list (or lists). The simplest form is:
2863
2864 [<expression> for <variable> in <sequence>]
2865
Guido van Rossum56db0952000-09-06 23:34:25 +00002866For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002867This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002868
2869You can also add a condition:
2870
2871 [<expression> for <variable> in <sequence> if <condition>]
2872
2873For example, [w for w in words if w == w.lower()] would yield the list
2874of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002875than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002876
2877You can also have nested for loops and more than one 'if' clause. For
2878example, here's a function that flattens a sequence of sequences::
2879
2880 def flatten(seq):
2881 return [x for subseq in seq for x in subseq]
2882
2883 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2884
2885This prints
2886
2887 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2888
2889List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002890Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002891
2892
2893Extended Import Statement
2894-------------------------
2895
2896Many people have asked for a way to import a module under a different
2897name. This can be accomplished like this:
2898
2899 import foo
2900 bar = foo
2901 del foo
2902
2903but this common idiom gets old quickly. A simple extension of the
2904import statement now allows this to be written as follows:
2905
2906 import foo as bar
2907
2908There's also a variant for 'from ... import':
2909
2910 from foo import bar as spam
2911
2912This also works with packages; e.g. you can write this:
2913
2914 import test.regrtest as regrtest
2915
2916Note that 'as' is not a new keyword -- it is recognized only in this
2917context (this is only possible because the syntax for the import
2918statement doesn't involve expressions).
2919
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002920Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002921
2922
2923Extended Print Statement
2924------------------------
2925
2926Easily the most controversial new feature, this extension to the print
2927statement adds an option to make the output go to a different file
2928than the default sys.stdout.
2929
2930For example, to write an error message to sys.stderr, you can now
2931write:
2932
2933 print >> sys.stderr, "Error: bad dog!"
2934
2935As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002936evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002937
2938 print >> None, "Hello world"
2939
2940is equivalent to
2941
2942 print "Hello world"
2943
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002944Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002945
2946
2947Optional Collection of Cyclical Garbage
2948---------------------------------------
2949
2950Python is now equipped with a garbage collector that can hunt down
2951cyclical references between Python objects. It's no replacement for
2952reference counting; in fact, it depends on the reference counts being
2953correct, and decides that a set of objects belong to a cycle if all
2954their reference counts can be accounted for from their references to
2955each other. This devious scheme was first proposed by Eric Tiedemann,
2956and brought to implementation by Neil Schemenauer.
2957
2958There's a module "gc" that lets you control some parameters of the
2959garbage collection. There's also an option to the configure script
2960that lets you enable or disable the garbage collection. In 2.0b1,
2961it's on by default, so that we (hopefully) can collect decent user
2962experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002963performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002964off by default in the final 2.0 release.
2965
2966
2967Smaller Changes
2968---------------
2969
2970A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2971map(None, seq1, seq2, ...) when the sequences have the same length;
2972i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2973the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002974zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002975
2976sys.version_info is a tuple (major, minor, micro, level, serial).
2977
2978Dictionaries have an odd new method, setdefault(key, default).
2979dict.setdefault(key, default) returns dict[key] if it exists; if not,
2980it sets dict[key] to default and returns that value. Thus:
2981
2982 dict.setdefault(key, []).append(item)
2983
2984does the same work as this common idiom:
2985
2986 if not dict.has_key(key):
2987 dict[key] = []
2988 dict[key].append(item)
2989
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002990There are two new variants of SyntaxError that are raised for
2991indentation-related errors: IndentationError and TabError.
2992
2993Changed \x to consume exactly two hex digits; see PEP 223. Added \U
2994escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00002995
2996The limits on the size of expressions and file in Python source code
2997have been raised from 2**16 to 2**32. Previous versions of Python
2998were limited because the maximum argument size the Python VM accepted
2999was 2**16. This limited the size of object constructor expressions,
3000e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3001limit was raised thanks to a patch by Charles Waldman that effectively
3002fixes the problem. It is now much more likely that you will be
3003limited by available memory than by an arbitrary limit in Python.
3004
3005The interpreter's maximum recursion depth can be modified by Python
3006programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3007limit is the maximum number of recursive calls that can be made by
3008Python code. The limit exists to prevent infinite recursion from
3009overflowing the C stack and causing a core dump. The default value is
30101000. The maximum safe value for a particular platform can be found
3011by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003012
3013New Modules and Packages
3014------------------------
3015
3016atexit - for registering functions to be called when Python exits.
3017
3018imputil - Greg Stein's alternative API for writing custom import
3019hooks.
3020
3021pyexpat - an interface to the Expat XML parser, contributed by Paul
3022Prescod.
3023
3024xml - a new package with XML support code organized (so far) in three
3025subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3026would fill a volume. There's a special feature whereby a
3027user-installed package named _xmlplus overrides the standard
3028xmlpackage; this is intended to give the XML SIG a hook to distribute
3029backwards-compatible updates to the standard xml package.
3030
3031webbrowser - a platform-independent API to launch a web browser.
3032
3033
Guido van Rossume905e952000-09-05 12:42:46 +00003034Changed Modules
3035---------------
3036
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003037array -- new methods for array objects: count, extend, index, pop, and
3038remove
3039
3040binascii -- new functions b2a_hex and a2b_hex that convert between
3041binary data and its hex representation
3042
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003043calendar -- Many new functions that support features including control
3044over which day of the week is the first day, returning strings instead
3045of printing them. Also new symbolic constants for days of week,
3046e.g. MONDAY, ..., SUNDAY.
3047
3048cgi -- FieldStorage objects have a getvalue method that works like a
3049dictionary's get method and returns the value attribute of the object.
3050
3051ConfigParser -- The parser object has new methods has_option,
3052remove_section, remove_option, set, and write. They allow the module
3053to be used for writing config files as well as reading them.
3054
3055ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003056optionally support the RFC 959 REST command.
3057
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003058gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003059
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003060httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3061the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003062
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003063locale -- implement getdefaultlocale for Win32 and Macintosh
3064
3065marshal -- no longer dumps core when marshaling deeply nested or
3066recursive data structures
3067
3068os -- new functions isatty, seteuid, setegid, setreuid, setregid
3069
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003070os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3071support under Unix.
3072
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003073os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003074
3075os.path -- fix semantics of os.path.commonprefix
3076
3077smtplib -- support for sending very long messages
3078
3079socket -- new function getfqdn()
3080
3081readline -- new functions to read, write and truncate history files.
3082The readline section of the library reference manual contains an
3083example.
3084
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003085select -- add interface to poll system call
3086
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003087shutil -- new copyfileobj function
3088
3089SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3090HTTP server.
3091
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003092Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003093
3094urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003095e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003096
3097whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003098
3099
3100Obsolete Modules
3101----------------
3102
3103None. However note that 1.6 made a whole slew of modules obsolete:
3104stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3105poly, zmod, strop, util, whatsound.
3106
3107
3108Changed, New, Obsolete Tools
3109----------------------------
3110
Tim Peters8b092332000-09-05 20:15:25 +00003111None.
Guido van Rossume905e952000-09-05 12:42:46 +00003112
3113
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003114C-level Changes
3115---------------
3116
3117Several cleanup jobs were carried out throughout the source code.
3118
3119All C code was converted to ANSI C; we got rid of all uses of the
3120Py_PROTO() macro, which makes the header files a lot more readable.
3121
3122Most of the portability hacks were moved to a new header file,
3123pyport.h; several other new header files were added and some old
3124header files were removed, in an attempt to create a more rational set
3125of header files. (Few of these ever need to be included explicitly;
3126they are all included by Python.h.)
3127
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003128Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003129and Win64, especially for the new Intel Itanium processor. Mick also
3130added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003131
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003132The C APIs to return an object's size have been update to consistently
3133use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3134previous versions, the abstract interfaces used PyXXX_Length and the
3135concrete interfaces used PyXXX_Size. The old names,
3136e.g. PyObject_Length, are still available for backwards compatibility
3137at the API level, but are deprecated.
3138
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003139The PyOS_CheckStack function has been implemented on Windows by
3140Fredrik Lundh. It prevents Python from failing with a stack overflow
3141on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003142
3143The GC changes resulted in creation of two new slots on object,
3144tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003145the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003146
3147The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003148C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003149
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003150PyErr_Format has been updated to automatically calculate the size of
3151the buffer needed to hold the formatted result string. This change
3152prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003153
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003154New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003155
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003156PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3157that are the same as their non-Ex counterparts except they take an
3158extra flag argument that tells them to close the file when done.
3159
3160XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003161
Tim Peters8b092332000-09-05 20:15:25 +00003162
3163Windows Changes
3164---------------
3165
3166New popen2/popen3/peopen4 in os module (see Changed Modules above).
3167
3168os.popen is much more usable on Windows 95 and 98. See Microsoft
3169Knowledge Base article Q150956. The Win9x workaround described there
3170is implemented by the new w9xpopen.exe helper in the root of your
3171Python installation. Note that Python uses this internally; it is not
3172a standalone program.
3173
3174Administrator privileges are no longer required to install Python
3175on Windows NT or Windows 2000. If you have administrator privileges,
3176Python's registry info will be written under HKEY_LOCAL_MACHINE.
3177Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003178under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003179uses of Python, but will prevent some advanced uses from working
3180(for example, running a Python script as an NT service, or possibly
3181from CGI).
3182
3183[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3184installer; instead, it installs the needed Tcl/Tk files directly in the
3185Python directory. If you already have a Tcl/Tk installation, this
3186wastes some disk space (about 4 Megs) but avoids problems with
3187conflicting Tcl/Tk installations, and makes it much easier for Python
3188to ensure that Tcl/Tk can find all its files.
3189
3190[This was new in 1.6] The Windows installer now installs by default in
3191\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3192
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003193
3194Updates to the changes between 1.5.2 and 1.6
3195--------------------------------------------
3196
3197The 1.6 NEWS file can't be changed after the release is done, so here
3198is some late-breaking news:
3199
3200New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3201and changes to getlocale() and setlocale().
3202
3203The new module is now enabled per default.
3204
3205It is not true that the encodings codecs cannot be used for normal
3206strings: the string.encode() (which is also present on 8-bit strings
3207!) allows using them for 8-bit strings too, e.g. to convert files from
3208cp1252 (Windows) to latin-1 or vice-versa.
3209
3210Japanese codecs are available from Tamito KAJIYAMA:
3211http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3212
3213
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003214======================================================================