blob: 1912dc2c9737dfd7f260df97556c8c8d2de7cb29 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Neal Norwitz649b7592002-01-01 19:07:13 +00009- file.xreadlines() now raises a ValueError if the file is closed:
10 Previously, an xreadlines object was returned which would raise
11 a ValueError when the xreadlines.next() method was called.
12
Tim Petersaf8446f2001-12-21 21:36:50 +000013Extension modules
14
Neal Norwitze790eae2002-01-01 21:14:12 +000015- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000016 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
17 is called.
18
Tim Petersaf8446f2001-12-21 21:36:50 +000019Library
20
Guido van Rossum606fe4e2001-12-28 20:57:14 +000021- ftplib: to safeguard the user's privacy, anonymous login will use
22 "anonymous@" as default password, rather than the real user and host
23 name.
24
Tim Petersaf8446f2001-12-21 21:36:50 +000025Tools/Demos
26
27Build
28
29C API
30
Martin v. Löwis7198a522002-01-01 19:59:11 +000031- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
32
Tim Peters10a3bb52001-12-25 19:07:38 +000033- An old #define of ANY as void has been removed from pyport.h. This
34 hasn't been used since Python's pre-ANSI days, and the #define has
35 been marked as obsolete since then. SF bug 495548 says it created
36 conflicts with other packages, so keeping it around wasn't harmless.
37
Tim Petersaf8446f2001-12-21 21:36:50 +000038- Because Python's magic number scheme broke on January 1st, we decided
39 to stop Python development. Thanks for all the fish!
40
41New platforms
42
Martin v. Löwisa6e97582002-01-01 18:41:33 +000043- GNU/Hurd is now supported.
44
Tim Petersaf8446f2001-12-21 21:36:50 +000045Tests
46
47Windows
48
49Mac
50
51
Tim Peters909c0912001-12-14 23:16:18 +000052What's New in Python 2.2 final?
53Release date: 21-Dec-2001
54===============================
55
56Type/class unification and new-style classes
57
Barry Warsaw52acb492001-12-21 20:04:22 +000058- pickle.py, cPickle: allow pickling instances of new-style classes
59 with a custom metaclass.
60
Tim Peters909c0912001-12-14 23:16:18 +000061Core and builtins
62
Barry Warsaw52acb492001-12-21 20:04:22 +000063- weakref proxy object: when comparing, unwrap both arguments if both
64 are proxies.
65
Tim Peters909c0912001-12-14 23:16:18 +000066Extension modules
67
Barry Warsaw52acb492001-12-21 20:04:22 +000068- binascii.b2a_base64(): fix a potential buffer overrun when encoding
69 very short strings.
70
71- cPickle: the obscure "fast" mode was suspected of causing stack
72 overflows on the Mac. Hopefully fixed this by setting the recursion
73 limit much smaller. If the limit is too low (it only affects
74 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
75 when compiling cPickle.c (or in pyconfig.h).
76
Tim Peters909c0912001-12-14 23:16:18 +000077Library
78
Barry Warsaw52acb492001-12-21 20:04:22 +000079- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
80 close or delete time).
81
82- rfc822.py: fixed a bug where the address '<>' was converted to None
83 instead of an empty string (also fixes the email.Utils module).
84
85- xmlrpclib.py: version 1.0.0; uses precision for doubles.
86
87- test suite: the pickle and cPickle tests were not executing any code
88 when run from the standard regresssion test.
89
Tim Peters909c0912001-12-14 23:16:18 +000090Tools/Demos
91
92Build
93
94C API
95
96New platforms
97
98Tests
99
100Windows
101
Barry Warsaw52acb492001-12-21 20:04:22 +0000102- distutils package: fixed broken Windows installers (bdist_wininst).
103
104- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
105 instances are deleted at process exit time.
106
107- socket.py: prevent mysterious warnings when socket instances are
108 deleted at process exit time.
109
110- posixmodule.c: fix a Windows crash with stat() of a filename ending
111 in backslash.
112
Tim Peters909c0912001-12-14 23:16:18 +0000113Mac
114
Barry Warsaw52acb492001-12-21 20:04:22 +0000115- The Carbon toolbox modules have been upgraded to Universal Headers
116 3.4, and experimental CoreGraphics and CarbonEvents modules have
117 been added. All only for framework-enabled MacOSX.
118
Tim Peters909c0912001-12-14 23:16:18 +0000119
Tim Peters6272dfd2001-12-13 19:34:00 +0000120What's New in Python 2.2c1?
121Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000122===========================
123
124Type/class unification and new-style classes
125
Barry Warsaw06557452001-12-14 20:47:12 +0000126- Guido's tutorial introduction to the new type/class features has
127 been extensively updated. See
128
129 http://www.python.org/2.2/descrintro.html
130
131 That remains the primary documentation in this area.
132
Guido van Rossum33bab012001-12-05 22:45:48 +0000133- Fixed a leak: instance variables declared with __slots__ were never
134 deleted!
135
Guido van Rossum4b800852001-12-03 00:54:52 +0000136- The "delete attribute" method of descriptor objects is called
137 __delete__, not __del__. In previous releases, it was mistakenly
138 called __del__, which created an unfortunate overloading condition
139 with finalizers. (The "get attribute" and "set attribute" methods
140 are still called __get__ and __set__, respectively.)
141
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000142- Some subtle issues with the super built-in were fixed:
143
144 (a) When super itself is subclassed, its __get__ method would still
145 return an instance of the base class (i.e., of super).
146
147 (b) super(C, C()).__class__ would return C rather than super. This
148 is confusing. To fix this, I decided to change the semantics of
149 super so that it only applies to code attributes, not to data
150 attributes. After all, overriding data attributes is not
151 supported anyway.
152
153 (c) The __get__ method didn't check whether the argument was an
154 instance of the type used in creation of the super instance.
155
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000156- Previously, hash() of an instance of a subclass of a mutable type
157 (list or dictionary) would return some value, rather than raising
158 TypeError. This has been fixed. Also, directly calling
159 dict.__hash__ and list.__hash__ now raises the same TypeError
160 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000161
Guido van Rossumd331cb52001-12-05 19:46:42 +0000162- New-style objects now support deleting their __dict__. This is for
163 all intents and purposes equivalent to assigning a brand new empty
164 dictionary, but saves space if the object is not used further.
165
Tim Petersb3c9af12001-11-17 00:21:57 +0000166Core and builtins
167
Tim Peters3caca232001-12-06 06:23:26 +0000168- -Qnew now works as documented in PEP 238: when -Qnew is passed on
169 the command line, all occurrences of "/" use true division instead
170 of classic division. See the PEP for details. Note that "all"
171 means all instances in library and 3rd-party modules, as well as in
172 your own code. As the PEP says, -Qnew is intended for use only in
173 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000174 Note that test_coercion.py in the standard Python test suite fails
175 under -Qnew; this is expected, and won't be repaired until true
176 division becomes the default (in the meantime, test_coercion is
177 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000178
Fred Drake6c01e252001-12-14 17:08:12 +0000179- complex() now only allows the first argument to be a string
180 argument, and raises TypeError if either the second arg is a string
181 or if the second arg is specified when the first is a string.
182
Tim Petersb3c9af12001-11-17 00:21:57 +0000183Extension modules
184
Martin v. Löwis560da622001-11-24 09:24:51 +0000185- gc.get_referents was renamed to gc.get_referrers.
186
Tim Petersb3c9af12001-11-17 00:21:57 +0000187Library
188
Tim Peters25059d32001-12-07 20:35:43 +0000189- Functions in the os.spawn() family now release the global interpreter
190 lock around calling the platform spawn. They should always have done
191 this, but did not before 2.2c1. Multithreaded programs calling
192 an os.spawn function with P_WAIT will no longer block all Python threads
193 until the spawned program completes. It's possible that some programs
194 relies on blocking, although more likely by accident than by design.
195
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000196- webbrowser defaults to netscape.exe on OS/2 now.
197
Martin v. Löwis652e1912001-11-25 14:50:56 +0000198- Tix.ResizeHandle exposes detach_widget, hide, and show.
199
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000200- The charset alias windows_1252 has been added.
201
Barry Warsaw06557452001-12-14 20:47:12 +0000202- types.StringTypes is a tuple containing the defined string types;
203 usually this will be (str, unicode), but if Python was compiled
204 without Unicode support it will be just (str,).
205
206- The pulldom and minidom modules were synchronized to PyXML.
207
Tim Petersb3c9af12001-11-17 00:21:57 +0000208Tools/Demos
209
Barry Warsaw06557452001-12-14 20:47:12 +0000210- A new script called Tools/scripts/google.py was added, which fires
211 off a search on Google.
212
Tim Petersb3c9af12001-11-17 00:21:57 +0000213Build
214
Barry Warsaw06557452001-12-14 20:47:12 +0000215- Note that release builds of Python should arrange to define the
216 preprocessor symbol NDEBUG on the command line (or equivalent).
217 In the 2.2 pre-release series we tried to define this by magic in
218 Python.h instead, but it proved to cause problems for extension
219 authors. The Unix, Windows and Mac builds now all define NDEBUG in
220 release builds via cmdline (or equivalent) instead. Ports to
221 other platforms should do likewise.
222
Jack Jansen1999ef42001-12-06 21:47:20 +0000223- It is no longer necessary to use --with-suffix when building on a
224 case-insensitive file system (such as Mac OS X HFS+). In the build
225 directory an extension is used, but not in the installed python.
226
Tim Petersb3c9af12001-11-17 00:21:57 +0000227C API
228
Tim Petersf582b822001-12-11 18:51:08 +0000229- New function PyDict_MergeFromSeq2() exposes the builtin dict
230 constructor's logic for updating a dictionary from an iterable object
231 producing key-value pairs.
232
Tim Peterscffed4b2001-11-29 03:26:37 +0000233- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000234 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000235 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
236 dump core in some bad cases. This has been repaired. As a result,
237 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
238 previously went unchallenged.
239
Tim Petersb3c9af12001-11-17 00:21:57 +0000240New platforms
241
242Tests
243
244Windows
245
246Mac
247
Jack Jansenffa260f2001-12-06 21:14:00 +0000248- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
249 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000250
Barry Warsaw06557452001-12-14 20:47:12 +0000251- Changed logic for finding python home in Mac OS X framework Pythons.
252 Now sys.executable points to the executable again, in stead of to
253 the shared library. The latter is used only for locating the python
254 home.
255
256
Tim Peters84362bc2001-10-19 17:55:30 +0000257What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000258Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000259===========================
260
261Type/class unification and new-style classes
262
Guido van Rossum3d27df02001-11-15 20:27:54 +0000263- Multiple inheritance mixing new-style and classic classes in the
264 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000265
266 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000267 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000268
269 The MRO (method resolution order) for each base class is respected
270 according to its kind, but the MRO for the derived class is computed
271 using new-style MRO rules if any base clase is a new-style class.
272 This needs to be documented.
273
Tim Petersa427a2b2001-10-29 22:25:45 +0000274- The new builtin dictionary() constructor, and dictionary type, have
275 been renamed to dict. This reflects a decade of common usage.
276
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000277- dict() now accepts an iterable object producing 2-sequences. For
278 example, dict(d.items()) == d for any dictionary d. The argument,
279 and the elements of the argument, can be any iterable objects.
280
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000281- New-style classes can now have a __del__ method, which is called
282 when the instance is deleted (just like for classic classes).
283
Guido van Rossum12d955c2001-10-26 14:56:06 +0000284- Assignment to object.__dict__ is now possible, for objects that are
285 instances of new-style classes that have a __dict__ (unless the base
286 class forbids it).
287
Guido van Rossumc8e56452001-10-22 00:43:43 +0000288- Methods of built-in types now properly check for keyword arguments
289 (formerly these were silently ignored). The only built-in methods
290 that take keyword arguments are __call__, __init__ and __new__.
291
Guido van Rossum86443212001-10-27 22:28:54 +0000292- The socket function has been converted to a type; see below.
293
Tim Peters84362bc2001-10-19 17:55:30 +0000294Core and builtins
295
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000296- Assignment to __debug__ raises SyntaxError at compile-time. This
297 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000298 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000299
Guido van Rossum12d955c2001-10-26 14:56:06 +0000300- Clarified the error messages for unsupported operands to an operator
301 (like 1 + '').
302
Tim Peters84362bc2001-10-19 17:55:30 +0000303Extension modules
304
Tim Peters5ebfd362001-11-13 23:11:19 +0000305- mmap has a new keyword argument, "access", allowing a uniform way for
306 both Windows and Unix users to create read-only, write-through and
307 copy-on-write memory mappings. This was previously possible only on
308 Unix. A new keyword argument was required to support this in a
309 uniform way because the mmap() signuatures had diverged across
310 platforms. Thanks to Jay T Miller for repairing this!
311
Tim Peters169ded02001-11-03 19:57:21 +0000312- By default, the gc.garbage list now contains only those instances in
313 unreachable cycles that have __del__ methods; in 2.1 it contained all
314 instances in unreachable cycles. "Instances" here has been generalized
315 to include instances of both new-style and old-style classes.
316
Guido van Rossum12d955c2001-10-26 14:56:06 +0000317- The socket module defines a new method for socket objects,
318 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000319 send() until all data has been sent. Also, the socket function has
320 been converted to a subclassable type, like list and tuple (etc.)
321 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000322
323- Various bugfixes to the curses module. There is now a test suite
324 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000325
Guido van Rossum692adf12001-10-30 03:03:03 +0000326- binascii.b2a_base64 no longer places an arbitrary restriction of 57
327 bytes on its input.
328
Tim Peters84362bc2001-10-19 17:55:30 +0000329Library
330
Tim Peters5ebfd362001-11-13 23:11:19 +0000331- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000332 convenience function.
333
Tim Peters75335872001-11-03 19:35:43 +0000334- Symbolic group names in regular expressions must be unique. For
335 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
336 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000337 Python 2.2 detects this error at regexp compilation time;
338 previously, the error went undetected, and results were
339 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
340 pattern.subn() methods have been rewritten in C. Also, an
341 experimental function/method finditer() has been added, which works
342 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000343
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000344- Tix exposes more commands through the classes DirSelectBox,
345 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
346 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
347 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
348
Tim Peters98791af2001-10-23 01:59:54 +0000349- Traceback objects are now scanned by cyclic garbage collection, so
350 cycles created by casual use of sys.exc_info() no longer cause
351 permanent memory leaks (provided garbage collection is enabled).
352
Guido van Rossum49192142001-10-24 20:51:44 +0000353- os.extsep -- a new variable needed by the RISCOS support. It is the
354 separator used by extensions, and is '.' on all platforms except
355 RISCOS, where it is '/'. There is no need to use this variable
356 unless you have a masochistic desire to port your code to RISCOS.
357
Barry Warsaw012852b2001-11-16 16:17:27 +0000358- mimetypes.py has optional support for non-standard, but commonly
359 found types. guess_type() and guess_extension() now accept an
360 optional `strict' flag, defaulting to true, which controls whether
361 recognize non-standard types or not. A few non-standard types we
362 know about have been added. Also, when run as a script, there are
363 new -l and -e options.
364
365- statcache is now deprecated.
366
367- email.Utils.formatdate() now produces the preferred RFC 2822 style
368 dates with numeric timezones (it used to produce obsolete dates
369 hard coded to "GMT" timezone). An optional `localtime' flag is
370 added to produce dates in the local timezone, with daylight savings
371 time properly taken into account.
372
373- In pickle and cPickle, instead of masking errors in load() by
374 transforming them into SystemError, we let the original exception
375 propagate out. Also, implement support for __safe_for_unpickling__
376 in pickle, as it already was supported in cPickle.
377
Tim Peters84362bc2001-10-19 17:55:30 +0000378Tools/Demos
379
380Build
381
Barry Warsaw012852b2001-11-16 16:17:27 +0000382- The dbm module is built using libdb1 if available. The bsddb module
383 is built with libdb3 if available.
384
385- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
386
Tim Peters84362bc2001-10-19 17:55:30 +0000387C API
388
Tim Peters1fc240e2001-10-26 05:06:50 +0000389- New function PySequence_Fast_GET_SIZE() returns the size of a non-
390 NULL result from PySequence_Fast(), more quickly than calling
391 PySequence_Size().
392
Barry Warsaw012852b2001-11-16 16:17:27 +0000393- New argument unpacking function PyArg_UnpackTuple() added.
394
395- New functions PyObject_CallFunctionObjArgs() and
396 PyObject_CallMethodObjArgs() have been added to make it more
397 convenient and efficient to call functions and methods from C.
398
399- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
400 possible that this will propagate errors it didn't before.
401
402- New function PyObject_CheckReadBuffer(), which returns true if its
403 argument supports the single-segment readable buffer interface.
404
Tim Peters84362bc2001-10-19 17:55:30 +0000405New platforms
406
Guido van Rossum86443212001-10-27 22:28:54 +0000407- We've finally confirmed that this release builds on HP-UX 11.00,
408 *with* threads, and passes the test suite.
409
Tim Peters7a33d8b2001-11-05 02:51:07 +0000410- Thanks to a series of patches from Michael Muller, Python may build
411 again under OS/2 Visual Age C++.
412
Guido van Rossum49192142001-10-24 20:51:44 +0000413- Updated RISCOS port by Dietmar Schwertberger.
414
Tim Peters84362bc2001-10-19 17:55:30 +0000415Tests
416
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000417- Added a test script for the curses module. It isn't run automatically;
418 regrtest.py must be run with '-u curses' to enable it.
419
Tim Peters84362bc2001-10-19 17:55:30 +0000420Windows
421
Barry Warsaw012852b2001-11-16 16:17:27 +0000422Mac
423
424- PythonScript has been moved to unsupported and is slated to be
425 removed completely in the next release.
426
427- It should now be possible to build applets that work on both OS9 and
428 OSX.
429
430- The core is now linked with CoreServices not Carbon; as a side
431 result, default 8bit encoding on OSX is now ASCII.
432
433- Python should now build on OSX 10.1.1
434
Tim Peters84362bc2001-10-19 17:55:30 +0000435
Tim Petersabf925f2001-09-28 21:53:42 +0000436What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000437Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000438===========================
439
440Type/class unification and new-style classes
441
Guido van Rossum687ae002001-10-15 22:03:32 +0000442- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000443 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000444 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000445 remains: the __dict__ of a new-style class is a read-only proxy; you
446 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000447 __defined__ attribute of new-style types no longer exists, for lack
448 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000449 future a __cache__ may be resurrected with a similar function, if I
450 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000451
Tim Peters1c9ca872001-10-04 06:43:12 +0000452- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
453 always returned None, even when there was a class docstring).
454
455- doctest now finds and runs docstrings attached to new-style classes,
456 class methods, static methods, and properties.
457
Guido van Rossum9074ef62001-10-16 21:34:49 +0000458Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000459
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000460- A very subtle syntactical pitfall in list comprehensions was fixed.
461 For example: [a+b for a in 'abc', for b in 'def']. The comma in
462 this example is a mistake. Previously, this would silently let 'a'
463 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
464 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
465 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
466 Note that [a for a in <singleton>] is a convoluted way to say
467 [<singleton>] anyway, so it's not like any expressiveness is lost.
468
Guido van Rossum9074ef62001-10-16 21:34:49 +0000469- getattr(obj, name, default) now only catches AttributeError, as
470 documented, rather than returning the default value for all
471 exceptions (which could mask bugs in a __getattr__ hook, for
472 example).
473
Fred Drakecb7a6b52001-10-22 18:41:51 +0000474- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000475 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000476 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000477 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000478
Guido van Rossum1c486092001-10-19 02:05:35 +0000479- unicode(obj) now behaves more like str(obj), accepting arbitrary
480 objects, and calling a __unicode__ method if it exists.
481 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000482 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000483
Barry Warsawf6fb1712001-10-19 05:35:40 +0000484- isinstance() now allows any object as the first argument and a
485 class, a type or something with a __bases__ tuple attribute for the
486 second argument. The second argument may also be a tuple of a
487 class, type, or something with __bases__, in which case isinstance()
488 will return true if the first argument is an instance of any of the
489 things contained in the second argument tuple. E.g.
490
491 isinstance(x, (A, B))
492
493 returns true if x is an instance of A or B.
494
Guido van Rossum9074ef62001-10-16 21:34:49 +0000495Extension modules
496
497- thread.start_new_thread() now returns the thread ID (previously None).
498
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000499- binascii has now two quopri support functions, a2b_qp and b2a_qp.
500
Guido van Rossumc524d952001-10-19 01:31:59 +0000501- readline now supports setting the startup_hook and the
502 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000503
Guido van Rossumc524d952001-10-19 01:31:59 +0000504- os and posix supports chroot(), setgroups() and unsetenv() where
505 available. The stat(), fstat(), statvfs() and fstatvfs() functions
506 now return "pseudo-sequences" -- the various fields can now be
507 accessed as attributes (e.g. os.stat("/").st_mtime) but for
508 backwards compatibility they also behave as a fixed-length sequence.
509 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000510 attributes.
511
512- time: localtime(), gmtime() and strptime() now return a
513 pseudo-sequence similar to the os.stat() return value, with
514 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000515
Guido van Rossum9074ef62001-10-16 21:34:49 +0000516- Decompression objects in the zlib module now accept an optional
517 second parameter to decompress() that specifies the maximum amount
518 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000519
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000520- optional SSL support in the socket module now exports OpenSSL
521 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
522 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000523 automatically seed its PRNG. Also, the keyfile and certfile
524 arguments to socket.ssl() are now optional.
525
526- posixmodule (and by extension, the os module on POSIX platforms) now
527 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000528
Guido van Rossum9074ef62001-10-16 21:34:49 +0000529Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000530
Tim Peters7402f792001-10-02 03:53:41 +0000531- doctest now excludes functions and classes not defined by the module
532 being tested, thanks to Tim Hochberg.
533
Fred Drakecb7a6b52001-10-22 18:41:51 +0000534- HotShot, a new profiler implemented using a C-based callback, has
535 been added. This substantially reduces the overhead of profiling,
536 but it is still quite preliminary. Support modules and
537 documentation will be added in upcoming releases (before 2.2 final).
538
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000539- profile now produces correct output in situations where an exception
540 raised in Python is cleared by C code (e.g. hasattr()). This used
541 to cause wrong output, including spurious claims of recursive
542 functions and attribution of time spent to the wrong function.
543
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000544 The code and documentation for the derived OldProfile and HotProfile
545 profiling classes was removed. The code hasn't worked for years (if
546 you tried to use them, they raised exceptions). OldProfile
547 intended to reproduce the behavior of the profiler Python used more
548 than 7 years ago, and isn't interesting anymore. HotProfile intended
549 to provide a faster profiler (but producing less information), and
550 that's a worthy goal we intend to meet via a different approach (but
551 without losing information).
552
Tim Peterscce092d2001-10-09 05:31:56 +0000553- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000554 a much better system-specific calibration constant. The constant can
555 now be specified in an instance constructor, or as a Profile class or
556 instance variable, instead of by editing profile.py's source code.
557 Calibration must still be done manually (see the docs for the profile
558 module).
559
560 Note that Profile.calibrate() must be overriden by subclasses.
561 Improving the accuracy required exploiting detailed knowledge of
562 profiler internals; the earlier method abstracted away the details
563 and measured a simplified model instead, but consequently computed
564 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000565
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000566- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000567 which indicates whether output is intended for the header 'Q'
568 encoding.
569
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000570- The SocketServer.ThreadingMixIn class now closes the request after
571 finish_request() returns. (Not when it errors out though.)
572
Barry Warsawf6fb1712001-10-19 05:35:40 +0000573- The nntplib module's NNTP.body() method has grown a `file' argument
574 to allow saving the message body to a file.
575
576- The email package has added a class email.Parser.HeaderParser which
577 only parses headers and does not recurse into the message's body.
578 Also, the module/class MIMEAudio has been added for representing
579 audio data (contributed by Anthony Baxter).
580
581- ftplib should be able to handle files > 2GB.
582
583- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
584 ON, and OFF.
585
Fred Drakecb7a6b52001-10-22 18:41:51 +0000586- xml.dom.minidom NodeList objects now support the length attribute
587 and item() method as required by the DOM specifications.
588
Guido van Rossumed554f62001-10-02 23:15:37 +0000589Tools/Demos
590
591- Demo/dns was removed. It no longer serves any purpose; a package
592 derived from it is now maintained by Anthony Baxter, see
593 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000594
Barry Warsawf6fb1712001-10-19 05:35:40 +0000595- The freeze tool has been made more robust, and two new options have
596 been added: -X and -E.
597
Tim Petersabf925f2001-09-28 21:53:42 +0000598Build
599
Barry Warsawf6fb1712001-10-19 05:35:40 +0000600- configure will use CXX in LINKCC if CXX is used to build main() and
601 the system requires to link a C++ main using the C++ compiler.
602
Tim Petersabf925f2001-09-28 21:53:42 +0000603C API
604
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000605- The documentation for the tp_compare slot is updated to require that
606 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
607 not correct. This is not yet enforced but will be enforced in
608 Python 2.3; even later, we may use -2 to indicate errors and +2 for
609 "NotImplemented". Right now, -1 should be used for an error return.
610
Tim Petersd38b1c72001-09-30 05:09:37 +0000611- PyLong_AsLongLong() now accepts int (as well as long) arguments.
612 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
613 as long) arguments.
614
Guido van Rossum3c288632001-10-16 21:13:49 +0000615- PyThread_start_new_thread() now returns a long int giving the thread
616 ID, if one can be calculated; it returns -1 for error, 0 if no
617 thread ID is calculated (this is an incompatible change, but only
618 the thread module used this API). This code has only really been
619 tested on Linux and Windows; other platforms please beware (and
620 report any bugs or strange behavior).
621
Guido van Rossum1c486092001-10-19 02:05:35 +0000622- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
623 input.
624
Tim Petersabf925f2001-09-28 21:53:42 +0000625New platforms
626
627Tests
628
629Windows
630
Tim Peters04cf1d32001-10-09 22:39:40 +0000631- Installer: If you install IDLE, and don't disable file-extension
632 registration, a new "Edit with IDLE" context (right-click) menu entry
633 is created for .py and .pyw files.
634
Tim Peters1ce3cf72001-10-01 17:58:40 +0000635- The signal module now supports SIGBREAK on Windows, thanks to Steven
636 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
637 action remains to call Win32 ExitProcess(). This can be changed via
638 signal.signal(). For example:
639
640 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
641 # (SIGINT) behavior.
642 import signal
643 signal.signal(signal.SIGBREAK,
644 signal.default_int_handler)
645
646 try:
647 while 1:
648 pass
649 except KeyboardInterrupt:
650 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
651 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
652 # program without the possibility for any Python-level cleanup).
653 print "Clean exit"
654
Tim Petersabf925f2001-09-28 21:53:42 +0000655
Tim Petersb07352e2001-09-08 01:25:47 +0000656What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000657Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000658===========================
659
Guido van Rossum808eea72001-09-25 04:15:41 +0000660Type/class unification and new-style classes
661
662- pydoc and inspect are now aware of new-style classes;
663 e.g. help(list) at the interactive prompt now shows proper
664 documentation for all operations on list objects.
665
666- Applications using Jim Fulton's ExtensionClass module can now safely
667 be used with Python 2.2. In particular, Zope 2.4.1 now works with
668 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
669 examples also work again. It is hoped that Gtk and Boost also work
670 with 2.2a4 and beyond. (If you can confirm this, please write
671 webmaster@python.org; if there are still problems, please open a bug
672 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000673
Tim Peters66c1a522001-09-24 21:17:50 +0000674- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
675 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
676 in the constructed property object. fget, fset and fdel weren't
677 discoverable from Python in 2.2a3. __doc__ is new, and allows to
678 associate a docstring with a property.
679
Guido van Rossum808eea72001-09-25 04:15:41 +0000680- Comparison overloading is now more completely implemented. For
681 example, a str subclass instance can properly be compared to a str
682 instance, and it can properly overload comparison. Ditto for most
683 other built-in object types.
684
685- The repr() of new-style classes has changed; instead of <type
686 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
687 *except* for built-in types, which are still rendered as <type
688 'Foo'> (to avoid upsetting existing code that might parse or
689 otherwise rely on repr() of certain type objects).
690
691- The repr() of new-style objects is now always <Foo object at XXX>;
692 previously, it was sometimes <Foo instance at XXX>.
693
694- For new-style classes, what was previously called __getattr__ is now
695 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000696 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000697 one in classic classes is defined which is called only if regular
698 attribute access raises AttributeError; to catch *all* attribute
699 access, you can use __getattribute__ (for new-style classes). If
700 both are defined, __getattribute__ is called first, and if it raises
701 AttributeError, __getattr__ is called.
702
703- The __class__ attribute of new-style objects can be assigned to.
704 The new class must have the same C-level object layout as the old
705 class.
706
707- The builtin file type can be subclassed now. In the usual pattern,
708 "file" is the name of the builtin type, and file() is a new builtin
709 constructor, with the same signature as the builtin open() function.
710 file() is now the preferred way to open a file.
711
712- Previously, __new__ would only see sequential arguments passed to
713 the type in a constructor call; __init__ would see both sequential
714 and keyword arguments. This made no sense whatsoever any more, so
715 now both __new__ and __init__ see all arguments.
716
717- Previously, hash() applied to an instance of a subclass of str or
718 unicode always returned 0. This has been repaired.
719
720- Previously, an operation on an instance of a subclass of an
721 immutable type (int, long, float, complex, tuple, str, unicode),
722 where the subtype didn't override the operation (and so the
723 operation was handled by the builtin type), could return that
724 instance instead a value of the base type. For example, if s was of
725 a str sublass type, s[:] returned s as-is. Now it returns a str
726 with the same value as s.
727
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000728- Provisional support for pickling new-style objects has been added.
729
Guido van Rossum808eea72001-09-25 04:15:41 +0000730Core
731
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000732- file.writelines() now accepts any iterable object producing strings.
733
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000734- PyUnicode_FromEncodedObject() now works very much like
735 PyObject_Str(obj) in that it tries to use __str__/tp_str
736 on the object if the object is not a string or buffer. This
737 makes unicode() behave like str() when applied to non-string/buffer
738 objects.
739
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000740- PyFile_WriteObject now passes Unicode objects to the file's write
741 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000742 of a print statement must support Unicode objects, i.e. they must
743 at least convert them into ASCII strings.
744
Guido van Rossum624c8af2001-09-18 15:21:04 +0000745- Thread scheduling on Solaris should be improved; it is no longer
746 necessary to insert a small sleep at the start of a thread in order
747 to let other runnable threads be scheduled.
748
Tim Petersb07352e2001-09-08 01:25:47 +0000749Library
750
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000751- StringIO.StringIO instances and cStringIO.StringIO instances support
752 read character buffer compatible objects for their .write() methods.
753 These objects are converted to strings and then handled as such
754 by the instances.
755
Barry Warsaw2f600732001-09-24 04:28:10 +0000756- The "email" package has been added. This is basically a port of the
757 mimelib package <http://sf.net/projects/mimelib> with API changes
758 and some implementations updated to use iterators and generators.
759
Tim Peters8a9c2842001-09-22 21:30:22 +0000760- difflib.ndiff() and difflib.Differ.compare() are generators now. This
761 restores the ability of Tools/scripts/ndiff.py to start producing output
762 before the entire comparison is complete.
763
Barry Warsaw58b072d2001-09-22 04:44:21 +0000764- StringIO.StringIO instances and cStringIO.StringIO instances support
765 iteration just like file objects (i.e. their .readline() method is
766 called for each iteration until it returns an empty string).
767
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000768- The codecs module has grown four new helper APIs to access
769 builtin codecs: getencoder(), getdecoder(), getreader(),
770 getwriter().
771
Guido van Rossum624c8af2001-09-18 15:21:04 +0000772- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
773 simplifies writing XML RPC servers.
774
Barry Warsaw647d5e82001-09-28 17:01:02 +0000775- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000776 after interpretation of symbolic links. On non-Unix systems, this
777 is an alias for os.path.abspath().
778
Tim Peters16a77ad2001-09-08 04:00:12 +0000779- operator.indexOf() (PySequence_Index() in the C API) now works with any
780 iterable object.
781
Guido van Rossum624c8af2001-09-18 15:21:04 +0000782- smtplib now supports various authentication and security features of
783 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000784
Guido van Rossum624c8af2001-09-18 15:21:04 +0000785- hmac: a new module implementing keyed hashing for message
786 authentication.
787
788- mimetypes now recognizes more extensions and file types. At the
789 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000790
Guido van Rossum624c8af2001-09-18 15:21:04 +0000791- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000792 Python 2.2 bytecode generation. It has also been promoted from a
793 Tool to a standard library package. (Tools/compiler still exists as
794 a sample driver.)
795
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000796Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000797
Tim Petersb07352e2001-09-08 01:25:47 +0000798Build
799
Guido van Rossum624c8af2001-09-18 15:21:04 +0000800- Large file support (LFS) is now automatic when the platform supports
801 it; no more manual configuration tweaks are needed. On Linux, at
802 least, it's possible to have a system whose C library supports large
803 files but whose kernel doesn't; in this case, large file support is
804 still enabled but doesn't do you any good unless you upgrade your
805 kernel or share your Python executable with another system whose
806 kernel has large file support.
807
808- The configure script now supplies plausible defaults in a
809 cross-compilation environment. This doesn't mean that the supplied
810 values are always correct, or that cross-compilation now works
811 flawlessly -- but it's a first step (and it shuts up most of
812 autoconf's warnings about AC_TRY_RUN).
813
814- The Unix build is now a bit less chatty, courtesy of the parser
815 generator. The build is completely silent (except for errors) when
816 using "make -s", thanks to a -q option to setup.py.
817
Tim Petersb07352e2001-09-08 01:25:47 +0000818C API
819
Guido van Rossum624c8af2001-09-18 15:21:04 +0000820- The "structmember" API now supports some new flag bits to deny read
821 and/or write access to attributes in restricted execution mode.
822
Tim Petersb07352e2001-09-08 01:25:47 +0000823New platforms
824
Guido van Rossum624c8af2001-09-18 15:21:04 +0000825- Compaq's iPAQ handheld, running the "familiar" Linux distribution
826 (http://familiar.handhelds.org).
827
Tim Petersb07352e2001-09-08 01:25:47 +0000828Tests
829
Tim Peters8a9c2842001-09-22 21:30:22 +0000830- The "classic" standard tests, which work by comparing stdout to
831 an expected-output file under Lib/test/output/, no longer stop at
832 the first mismatch. Instead the test is run to completion, and a
833 variant of ndiff-style comparison is used to report all differences.
834 This is much easier to understand than the previous style of reporting.
835
836- The unittest-based standard tests now use regrtest's test_main()
837 convention, instead of running as a side-effect of merely being
838 imported. This allows these tests to be run in more natural and
839 flexible ways as unittests, outside the regrtest framework.
840
841- regrtest.py is much better integrated with unittest and doctest now,
842 especially in regard to reporting errors.
843
Tim Petersb07352e2001-09-08 01:25:47 +0000844Windows
845
Guido van Rossum624c8af2001-09-18 15:21:04 +0000846- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000847 that support it (NTFS under Windows 2000). See "What's New in
848 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000849
Tim Petersb07352e2001-09-08 01:25:47 +0000850
Tim Petersedc99312001-08-22 21:36:50 +0000851What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000852Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000853===========================
854
855Core
856
Tim Peters9fffa3e2001-09-04 05:14:19 +0000857- Conversion of long to float now raises OverflowError if the long is too
858 big to represent as a C double.
859
Tim Peters32f453e2001-09-03 08:35:41 +0000860- The 3-argument builtin pow() no longer allows a third non-None argument
861 if either of the first two arguments is a float, or if both are of
862 integer types and the second argument is negative (in which latter case
863 the arguments are converted to float, so this is really the same
864 restriction).
865
Tim Peters5d2b77c2001-09-03 05:47:38 +0000866- The builtin dir() now returns more information, and sometimes much
867 more, generally naming all attributes of an object, and all attributes
868 reachable from the object via its class, and from its class's base
869 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
870 an empty list. In 2.2a3,
871
872 >>> dir([])
873 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
874 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
875 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
876 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
877 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
878 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
879 'reverse', 'sort']
880
881 dir(module) continues to return only the module's attributes, though.
882
Tim Petersbdee63f2001-09-02 03:40:59 +0000883- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000884 than raising OverflowError. This is a partial implementation of PEP
885 237. You can use -Wdefault::OverflowWarning to enable a warning for
886 this situation, and -Werror::OverflowWarning to revert to the old
887 OverflowError exception.
888
Guido van Rossum61c345f2001-09-04 03:26:15 +0000889- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000890 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000891 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
892 -Qold, meaning the / operator has its classic meaning and no
893 warnings are issued. Using -Qwarn issues a run-time warning about
894 all uses of classic division for int and long arguments; -Qwarnall
895 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000896 (for use with fixdiv.py).
897 [Note: the remainder of this paragraph (preserved below) became
898 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
899 <obsolete>
900 Using -Qnew is questionable; it turns on new division by default, but
901 only in the __main__ module. You can usefully combine -Qwarn or
902 -Qwarnall and -Qnew: this gives the __main__ module new division, and
903 warns about classic division everywhere else.
904 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000905
Tim Petersbdee63f2001-09-02 03:40:59 +0000906- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000907 long, float, str, unicode, and tuple. (The types complex, list and
908 dictionary can also be subclassed; this was introduced earlier.)
909 Note that restrictions apply when subclassing immutable built-in
910 types: you can only affect the value of the instance by overloading
911 __new__. You can add mutable attributes, and the subclass instances
912 will have a __dict__ attribute, but you cannot change the "value"
913 (as implemented by the base class) of an immutable subclass instance
914 once it is created.
915
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000916- The dictionary constructor now takes an optional argument, a
917 mapping-like object, and initializes the dictionary from its
918 (key, value) pairs.
919
Tim Petersbdee63f2001-09-02 03:40:59 +0000920- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000921 "cooperative super calls" in a multiple inheritance setting. For an
922 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
923
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000924- A new built-in type, property, has been added. This enables the
925 creation of "properties". These are attributes implemented by
926 getter and setter functions (or only one of these for read-only or
927 write-only attributes), without the need to override __getattr__.
928 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000929
Tim Petersbdee63f2001-09-02 03:40:59 +0000930- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000931 liberalized, to allow leading zeroes. Examples of literals now
932 legal that were SyntaxErrors before:
933
934 00.0 0e3 0100j 07.5 00000000000000000008.
935
Tim Petersbdee63f2001-09-02 03:40:59 +0000936- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000937 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
938
Tim Petersedc99312001-08-22 21:36:50 +0000939Library
940
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000941- telnetlib includes symbolic names for the options, and support for
942 setting an option negotiation callback.
943
Tim Petersa40c7932001-09-05 22:36:56 +0000944- The new C standard no longer requires that math libraries set errno to
945 ERANGE on overflow. For platform libraries that exploit this new
946 freedom, Python's overflow-checking was wholly broken. A new overflow-
947 checking scheme attempts to repair that, but may not be reliable on all
948 platforms (C doesn't seem to provide anything both useful and portable
949 in this area anymore).
950
Martin v. Löwis44f86962001-09-05 13:44:54 +0000951- Asynchronous timeout actions are available through the new class
952 threading.Timer.
953
Tim Peters78526162001-09-05 00:53:45 +0000954- math.log and math.log10 now return sensible results for even huge
955 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
956
Tim Petersbdee63f2001-09-02 03:40:59 +0000957- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +0000958 currently held. See the docs for the imp module.
959
Tim Petersbdee63f2001-09-02 03:40:59 +0000960- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +0000961 dumps containing ints written on platforms where Python ints are 8 bytes.
962 When read on a box where Python ints are 4 bytes, such values are
963 converted to Python longs.
964
Tim Petersbdee63f2001-09-02 03:40:59 +0000965- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +0000966 code objects is no longer allowed. This plugs a security hole.
967
Steve Purcell6091cd62001-09-06 16:05:17 +0000968- unittest.TestResult instances no longer store references to tracebacks
969 generated by test failures. This prevents unexpected dangling references
970 to objects that should be garbage collected between tests.
971
Tim Petersedc99312001-08-22 21:36:50 +0000972Tools
973
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000974- Tools/scripts/fixdiv.py has been added which can be used to fix
975 division operators as per PEP 238.
976
Tim Petersedc99312001-08-22 21:36:50 +0000977Build
978
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000979- If you are an adventurous person using Mac OS X you may want to look at
980 Mac/OSX. There is a Makefile there that will build Python as a real Mac
981 application, which can be used for experimenting with Carbon or Cocoa.
982 Discussion of this on pythonmac-sig, please.
983
Tim Peters7eea37e2001-09-04 22:08:56 +0000984C API
985
986- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +0000987
Tim Peters9fffa3e2001-09-04 05:14:19 +0000988- Note that PyLong_AsDouble can fail! This has always been true, but no
989 callers checked for it. It's more likely to fail now, because overflow
990 errors are properly detected now. The proper way to check:
991
992 double x = PyLong_AsDouble(some_long_object);
993 if (x == -1.0 && PyErr_Occurred()) {
994 /* The conversion failed. */
995 }
996
Tim Petersbdee63f2001-09-02 03:40:59 +0000997- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +0000998 compile but will not participate in GC. To upgrade an extension
999 module:
1000
1001 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001002
Neil Schemenauer4042c692001-08-30 15:38:01 +00001003 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1004 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001005
Neil Schemenauer4042c692001-08-30 15:38:01 +00001006 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1007 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001008
Neil Schemenauer4042c692001-08-30 15:38:01 +00001009 - remove PyGC_HEAD_SIZE from object size calculations
1010
1011 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1012
Tim Petersbdee63f2001-09-02 03:40:59 +00001013- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001014 These can be used safely to construct string objects from a
1015 sprintf-style format string (similar to the format string supported
1016 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001017
Tim Petersedc99312001-08-22 21:36:50 +00001018New platforms
1019
Tim Petersb7da0902001-09-02 23:01:43 +00001020- Stephen Hansen contributed patches sufficient to get a clean compile
1021 under Borland C (Windows), but he reports problems running it and ran
1022 out of time to complete the port. Volunteers? Expect a MemoryError
1023 when importing the types module; this is probably shallow, and
1024 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001025
Tim Petersedc99312001-08-22 21:36:50 +00001026Tests
1027
1028Windows
1029
Tim Peters6e13a562001-09-06 00:32:15 +00001030- Large file support is now enabled on Win32 platforms as well as on
1031 Win64. This means that, for example, you can use f.tell() and f.seek()
1032 to manipulate files larger than 2 gigabytes (provided you have enough
1033 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001034 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1035 filesize limit, and large file support makes no difference there.
1036 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1037 NTFS has no practical limit on file size, and files of any size can be
1038 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001039
Tim Petersbdee63f2001-09-02 03:40:59 +00001040- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001041 points to command.com (patch from Brian Quinlan).
1042
Tim Petersedc99312001-08-22 21:36:50 +00001043
Tim Peters20f51a72001-07-21 02:31:40 +00001044What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001045Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001046===========================
1047
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001048Build
1049
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001050- Tim Peters developed a brand new Windows installer using Wise 8.1,
1051 generously donated to us by Wise Solutions.
1052
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001053- configure supports a new option --enable-unicode, with the values
1054 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1055 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001056
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001057- A new configure option --enable-framework builds a Mac OS X framework,
1058 which "make frameworkinstall" will install. This provides a starting
1059 point for more mac-like functionality, join pythonmac-sig@python.org
1060 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001061
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001062- The NeXT platform is no longer supported.
1063
1064- The `new' module is now statically linked.
1065
Tim Peters0afb6092001-08-15 06:06:44 +00001066Tools
1067
1068- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001069 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001070 the module docstring for details.
1071
Tim Peters20f51a72001-07-21 02:31:40 +00001072Tests
1073
Tim Peters5e824c32001-08-12 22:25:01 +00001074- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001075 platforms, allowing to give clearer test result output. regrtest
1076 also has optional --use/-u switch to run normally disabled tests
1077 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001078
Tim Peters20f51a72001-07-21 02:31:40 +00001079- Several new tests in the standard test suite, with special thanks to
1080 Nick Mathewson.
1081
1082Core
1083
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001084- The floor division operator // has been added as outlined in PEP
1085 238. The / operator still provides classic division (and will until
1086 Python 3.0) unless "from __future__ import division" is included, in
1087 which case the / operator will provide true division. The operator
1088 module provides truediv() and floordiv() functions. Augmented
1089 assignment variants are included, as are the equivalent overloadable
1090 methods and C API methods. See the PEP for a full discussion:
1091 <http://python.sf.net/peps/pep-0238.html>
1092
Tim Peters6cd6a822001-08-17 22:11:27 +00001093- Future statements are now effective in simulated interactive shells
1094 (like IDLE). This should "just work" by magic, but read Michael
1095 Hudson's "Future statements in simulated shells" PEP 264 for full
1096 details: <http://python.sf.net/peps/pep-0264.html>.
1097
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001098- The type/class unification (PEP 252-253) was integrated into the
1099 trunk and is not so tentative any more (the exact specification of
1100 some features is still tentative). A lot of work has done on fixing
1101 bugs and adding robustness and features (performance still has to
1102 come a long way).
1103
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001104- Warnings about a mismatch in the Python API during extension import
1105 now use the Python warning framework (which makes it possible to
1106 write filters for these warnings).
1107
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001108- A function's __dict__ (aka func_dict) will now always be a
1109 dictionary. It used to be possible to delete it or set it to None,
1110 but now both actions raise TypeErrors. It is still legal to set it
1111 to a dictionary object. Getting func.__dict__ before any attributes
1112 have been assigned now returns an empty dictionary instead of None.
1113
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001114- A new command line option, -E, was added which disables the use of
1115 all environment variables, or at least those that are specifically
1116 significant to Python. Usually those have a name starting with
1117 "PYTHON". This was used to fix a problem where the tests fail if
1118 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1119 older distribution.
1120
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001121Library
1122
Tim Peters5e824c32001-08-12 22:25:01 +00001123- New class Differ and new functions ndiff() and restore() in difflib.py.
1124 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001125 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001126
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001127- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1128 value using the minimal quoting required for the value; more
1129 reliable than using xml.sax.saxutils.escape() for attribute values.
1130
1131- Readline completion support for cmd.Cmd was added.
1132
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001133- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1134
1135- Added function threading.BoundedSemaphore()
1136
1137- Added Ka-Ping Yee's cgitb.py module.
1138
1139- The `new' module now exposes the CO_xxx flags.
1140
Martin v. Löwis560da622001-11-24 09:24:51 +00001141- The gc module offers the get_referents function.
1142
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001143New platforms
1144
1145C API
1146
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001147- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1148 which provide a cross-platform implementations for the
1149 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1150 the standard sprintf() and vsprintf() C lib APIs, these versions
1151 apply bounds checking on the used buffer which enhances protection
1152 against buffer overruns.
1153
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001154- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001155 and extensions using different Unicode widths is rendered next to
1156 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001157 will result in an ImportError. Unicode extensions writers must make
1158 sure to check the Unicode width compatibility in their extensions by
1159 using at least one of the mangled Unicode APIs in the extension.
1160
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001161- Two new flags METH_NOARGS and METH_O are available in method definition
1162 tables to simplify implementation of methods with no arguments and a
1163 single untyped argument. Calling such methods is more efficient than
1164 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1165 deprecated.
1166
Tim Petersc1731372001-08-04 08:12:36 +00001167Windows
1168
1169- "import module" now compiles module.pyw if it exists and nothing else
1170 relevant is found.
1171
Tim Peters20f51a72001-07-21 02:31:40 +00001172
Guido van Rossum55a78992001-07-17 17:22:32 +00001173What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001174Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001175===========================
1176
1177Core
Tim Petersa814db52001-05-14 07:05:58 +00001178
Tim Peters6d6c1a32001-08-02 04:15:00 +00001179- TENTATIVELY, a large amount of code implementing much of what's
1180 described in PEP 252 (Making Types Look More Like Classes) and PEP
1181 253 (Subtyping Built-in Types) was added. This will be released
1182 with Python 2.2a1. Documentation will be provided separately
1183 through http://www.python.org/2.2/. The purpose of releasing this
1184 with Python 2.2a1 is to test backwards compatibility. It is
1185 possible, though not likely, that a decision is made not to release
1186 this code as part of 2.2 final, if any serious backwards
1187 incompapatibilities are found during alpha testing that cannot be
1188 repaired.
1189
Guido van Rossum55a78992001-07-17 17:22:32 +00001190- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001191 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001192 more 'yield' statements. See PEP 255. Since this adds a new
1193 keyword to the language, this feature must be enabled by including a
1194 future statement: "from __future__ import generators" (see PEP 236).
1195 Generators will become a standard feature in a future release
1196 (probably 2.3). Without this future statement, 'yield' remains an
1197 ordinary identifier, but a warning is issued each time it is used.
1198 (These warnings currently don't conform to the warnings framework of
1199 PEP 230; we intend to fix this in 2.2a2.)
1200
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001201- The UTF-16 codec was modified to be more RFC compliant. It will now
1202 only remove BOM characters at the start of the string and then
1203 only if running in native mode (UTF-16-LE and -BE won't remove a
1204 leading BMO character).
1205
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001206- Strings now have a new method .decode() to complement the already
1207 existing .encode() method. These two methods provide direct access
1208 to the corresponding decoders and encoders of the registered codecs.
1209
1210 To enhance the usability of the .encode() method, the special
1211 casing of Unicode object return values was dropped (Unicode objects
1212 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001213
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001214 Both methods will now return whatever the codec in charge of the
1215 requested encoding returns as object, e.g. Unicode codecs will
1216 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1217 will return u"äöü"). This enables codec writer to create codecs
1218 for various simple to use conversions.
1219
1220 New codecs were added to demonstrate these new features (the .encode()
1221 and .decode() columns indicate the type of the returned objects):
1222
1223 Name | .encode() | .decode() | Description
1224 ----------------------------------------------------------------------
1225 uu | string | string | UU codec (e.g. for email)
1226 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001227 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001228 zlib | string | string | zlib compression
1229 hex | string | string | 2-byte hex codec
1230 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1231
Mark Hammond2a0af792001-05-14 03:09:36 +00001232- Some operating systems now support the concept of a default Unicode
1233 encoding for file system operations. Notably, Windows supports 'mbcs'
1234 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001235 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001236 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001237
1238 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001239 functions that return filenames (such as os.listdir()) to return Python
1240 string objects pre-encoded using the default file system encoding for
1241 the platform. As this encoding is likely to be different from Python's
1242 default encoding, converting this name to a Unicode object before passing
1243 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001244 would attempt to use its default encoding (generally ASCII) rather than
1245 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001246
Tim Petersa814db52001-05-14 07:05:58 +00001247 In general, this change simply removes surprises when working with
1248 Unicode and the file system, making these operations work as you expect,
1249 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001250 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001251
Tim Peters61dff2b2001-05-08 15:43:37 +00001252- Float (and complex) literals in source code were evaluated to full
1253 precision only when running from a .py file; the same code loaded from a
1254 .pyc (or .pyo) file could suffer numeric differences starting at about the
1255 12th significant decimal digit. For example, on a machine with IEEE-754
1256 floating arithmetic,
1257
1258 x = 9007199254740992.0
1259 print long(x)
1260
1261 printed 9007199254740992 if run directly from .py, but 9007199254740000
1262 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1263 str(float) instead of repr(float) when building code objects. marshal
1264 now uses repr(float) instead, which should reproduce floats to full
1265 machine precision (assuming the platform C float<->string I/O conversion
1266 functions are of good quality).
1267
1268 This may cause floating-point results to change in some cases, and
1269 usually for the better, but may also cause numerically unstable
1270 algorithms to break.
1271
Tim Peters2f228e72001-05-13 00:19:31 +00001272- The implementation of dicts suffers fewer collisions, which has speed
1273 benefits. However, the order in which dict entries appear in dict.keys(),
1274 dict.values() and dict.items() may differ from previous releases for a
1275 given dict. Nothing is defined about this order, so no program should
1276 rely on it. Nevertheless, it's easy to write test cases that rely on the
1277 order by accident, typically because of printing the str() or repr() of a
1278 dict to an "expected results" file. See Lib/test/test_support.py's new
1279 sortdict(dict) function for a simple way to display a dict in sorted
1280 order.
1281
Tim Peters7a3bfc32001-06-12 01:22:22 +00001282- Many other small changes to dicts were made, resulting in faster
1283 operation along the most common code paths.
1284
Guido van Rossum10315822001-05-01 20:54:30 +00001285- Dictionary objects now support the "in" operator: "x in dict" means
1286 the same as dict.has_key(x).
1287
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001288- The update() method of dictionaries now accepts generic mapping
1289 objects. Specifically the argument object must support the .keys()
1290 and __getitem__() methods. This allows you to say, for example,
1291 {}.update(UserDict())
1292
Guido van Rossum10315822001-05-01 20:54:30 +00001293- Iterators were added; this is a generalized way of providing values
1294 to a for loop. See PEP 234. There's a new built-in function iter()
1295 to return an iterator. There's a new protocol to get the next value
1296 from an iterator using the next() method (in Python) or the
1297 tp_iternext slot (in C). There's a new protocol to get iterators
1298 using the __iter__() method (in Python) or the tp_iter slot (in C).
1299 Iterating (i.e. a for loop) over a dictionary generates its keys.
1300 Iterating over a file generates its lines.
1301
Tim Petersf553f892001-05-01 20:45:31 +00001302- The following functions were generalized to work nicely with iterator
1303 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001304 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001305 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1306 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001307 join() method of strings
1308 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001309 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1310 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001311 right-hand side of assignment statements with multiple targets, such as
1312 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001313
Tim Petersd85e1022001-05-11 21:51:48 +00001314- Accessing module attributes is significantly faster (for example,
1315 random.random or os.path or yourPythonModule.yourAttribute).
1316
Tim Peterse63415e2001-05-08 04:38:29 +00001317- Comparing dictionary objects via == and != is faster, and now works even
1318 if the keys and values don't support comparisons other than ==.
1319
Tim Peters95bf9392001-05-10 08:32:44 +00001320- Comparing dictionaries in ways other than == and != is slower: there were
1321 insecurities in the dict comparison implementation that could cause Python
1322 to crash if the element comparison routines for the dict keys and/or
1323 values mutated the dicts. Making the code bulletproof slowed it down.
1324
Tim Peterseb28ef22001-06-02 05:27:19 +00001325- Collisions in dicts are resolved via a new approach, which can help
1326 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001327 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001328 faster now. Thanks to Christian Tismer for pointing out the cause and
1329 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001330
Tim Peters52e155e2001-06-16 05:42:57 +00001331- repr() is much faster for large containers (dict, list, tuple).
1332
1333
Tim Petersa814db52001-05-14 07:05:58 +00001334Library
1335
Fred Drake960fdf92001-07-20 18:38:26 +00001336- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1337 were added to the string module. These a locale-indenpendent
1338 constants, unlike letters, lowercase, and uppercase. These are now
1339 use in appropriate locations in the standard library.
1340
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001341- The flags used in dlopen calls can now be configured using
1342 sys.setdlopenflags and queried using sys.getdlopenflags.
1343
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001344- Fredrik Lundh's xmlrpclib is now a standard library module. This
1345 provides full client-side XML-RPC support. In addition,
1346 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1347 one asyncore-based). Thanks to Eric Raymond for the documentation.
1348
Guido van Rossum643d3912001-07-05 14:46:25 +00001349- The xrange() object is simplified: it no longer supports slicing,
1350 repetition, comparisons, efficient 'in' checking, the tolist()
1351 method, or the start, stop and step attributes. See PEP 260.
1352
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001353- A new function fnmatch.filter to filter lists of file names was added.
1354
Barry Warsawffd674d2001-05-22 16:00:10 +00001355- calendar.py uses month and day names based on the current locale.
1356
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001357- strop is now *really* obsolete (this was announced before with 1.6),
1358 and issues DeprecationWarning when used (except for the four items
1359 that are still imported into string.py).
1360
Tim Petersa814db52001-05-14 07:05:58 +00001361- Cookie.py now sorts key+value pairs by key in output strings.
1362
1363- pprint.isrecursive(object) didn't correctly identify recursive objects.
1364 Now it does.
1365
Tim Peters95b3f782001-05-14 18:39:41 +00001366- pprint functions now much faster for large containers (tuple, list, dict).
1367
Tim Peters7b9542a2001-06-10 23:40:19 +00001368- New 'q' and 'Q' format codes in the struct module, corresponding to C
1369 types "long long" and "unsigned long long" (on Windows, __int64). In
1370 native mode, these can be used only when the platform C compiler supports
1371 these types (when HAVE_LONG_LONG is #define'd by the Python config
1372 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001373 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1374 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001375
Guido van Rossum83213cc2001-06-12 16:48:52 +00001376- The site module installs a new built-in function 'help' that invokes
1377 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1378 it displays a message reminding the user to use 'help()' or
1379 'help(object)'.
1380
Tim Petersa814db52001-05-14 07:05:58 +00001381Tests
1382
1383- New test_mutants.py runs dict comparisons where the key and value
1384 comparison operators mutute the dicts randomly during comparison. This
1385 rapidly causes Python to crash under earlier releases (not for the faint
1386 of heart: it can also cause Win9x to freeze or reboot!).
1387
1388- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001389 pprint.isreadable() return sensible results. Also verifies that simple
1390 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001391
Tim Peters4324aa32001-05-28 22:30:08 +00001392C API
1393
1394- Removed the unused last_is_sticky argument from the internal
1395 _PyTuple_Resize(). If this affects you, you were cheating.
1396
1397
Guido van Rossum55a78992001-07-17 17:22:32 +00001398======================================================================
1399
1400
Guido van Rossumffe13be2001-04-16 18:46:45 +00001401What's New in Python 2.1 (final)?
1402=================================
1403
1404We only changed a few things since the last release candidate, all in
1405Python library code:
1406
1407- A bug in the locale module was fixed that affected locales which
1408 define no grouping for numeric formatting.
1409
1410- A few bugs in the weakref module's implementations of weak
1411 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1412 and the test suite was updated to check for these bugs.
1413
1414- An old bug in the os.path.walk() function (introduced in Python
1415 2.0!) was fixed: a non-existent file would cause an exception
1416 instead of being ignored.
1417
1418- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1419 PyChecker.
1420
1421
Guido van Rossum5b08f132001-04-16 02:05:23 +00001422What's New in Python 2.1c2?
1423===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001424
Guido van Rossum5b08f132001-04-16 02:05:23 +00001425A flurry of small changes, and one showstopper fixed in the nick of
1426time made it necessary to release another release candidate. The list
1427here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001428
Guido van Rossum5b08f132001-04-16 02:05:23 +00001429Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001430
Guido van Rossum5b08f132001-04-16 02:05:23 +00001431- Tim discovered a nasty bug in the dictionary code, caused by
1432 PyDict_Next() calling dict_resize(), and the GC code's use of
1433 PyDict_Next() violating an assumption in dict_items(). This was
1434 fixed with considerable amounts of band-aid, but the net effect is a
1435 saner and more robust implementation.
1436
1437- Made a bunch of symbols static that were accidentally global.
1438
1439Build and Ports
1440
1441- The setup.py script didn't check for a new enough version of zlib
1442 (1.1.3 is needed). Now it does.
1443
1444- Changed "make clean" target to also remove shared libraries.
1445
1446- Added a more general warning about the SGI Irix optimizer to README.
1447
1448Library
1449
1450- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1451 omitted the slash between host and file.html.
1452
1453- The mailbox module's _Mailbox class contained a completely broken
1454 and undocumented seek() method. Ripped it out.
1455
1456- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1457 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1458
1459- Fixed a few last-minute bugs in unittest.
1460
1461Extensions
1462
1463- Reverted the patch to the OpenSSL code in socketmodule.c to support
1464 RAND_status() and the EGD, and the subsequent patch that tried to
1465 fix it for pre-0.9.5 versions; the problem with the patch is that on
1466 some systems it issues a warning whenever socket is imported, and
1467 that's unacceptable.
1468
1469Tests
1470
1471- Fixed the pickle tests to work with "import test.test_pickle".
1472
1473- Tweaked test_locale.py to actually run the test Windows.
1474
1475- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1476 not "wb" (which is not a valid mode at all).
1477
1478- Fix pstats browser crashes. Import readline if it exists to make
1479 the user interface nicer.
1480
1481- Add "import thread" to the top of test modules that import the
1482 threading module (test_asynchat and test_threadedtempfile). This
1483 prevents test failures caused by a broken threading module resulting
1484 from a previously caught failed import.
1485
1486- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1487 needed on some platforms (e.g. Solaris 8) when the tests are run
1488 twice in succession.
1489
1490- Skip rather than fail test_sunaudiodev if no audio device is found.
1491
1492
1493What's New in Python 2.1c1?
1494===========================
1495
1496This list was significantly updated when 2.1c2 was released; the 2.1c1
1497release didn't mention most changes that were actually part of 2.1c1:
1498
1499Legal
1500
1501- Copyright was assigned to the Python Software Foundation (PSF) and a
1502 PSF license (very similar to the CNRI license) was added.
1503
1504- The CNRI copyright notice was updated to include 2001.
1505
1506Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001507
Guido van Rossumc9932722001-04-12 02:31:27 +00001508- After a public outcry, assignment to __debug__ is no longer illegal;
1509 instead, a warning is issued. It will become illegal in 2.2.
1510
Guido van Rossum5b08f132001-04-16 02:05:23 +00001511- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1512 "%#x" now always prepends "0x", even if the value is zero.
1513
1514- Fixed some nits in the bytecode compiler.
1515
1516- Fixed core dumps when calling certain kinds of non-functions.
1517
1518- Fixed various core dumps caused by reference count bugs.
1519
1520Build and Ports
1521
1522- Use INSTALL_SCRIPT to install script files.
1523
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001524- New port: SCO Unixware 7, by Billy G. Allie.
1525
Guido van Rossum5b08f132001-04-16 02:05:23 +00001526- Updated RISCOS port.
1527
1528- Updated BeOS port and notes.
1529
1530- Various other porting problems resolved.
1531
1532Library
1533
1534- The TERMIOS and SOCKET modules are now truly obsolete and
1535 unnecessary. Their symbols are incorporated in the termios and
1536 socket modules.
1537
1538- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1539 better tests for pickling.
1540
1541- threading: make Condition.wait() robust against KeyboardInterrupt.
1542
1543- zipfile: add support to zipfile to support opening an archive
1544 represented by an open file rather than a file name. Fix bug where
1545 the archive was not properly closed. Fixed a bug in this bugfix
1546 where flush() was called for a read-only file.
1547
1548- imputil: added an uninstall() method to the ImportManager.
1549
1550- Canvas: fixed bugs in lower() and tkraise() methods.
1551
1552- SocketServer: API change (added overridable close_request() method)
1553 so that the TCP server can explicitly close the request.
1554
1555- pstats: Eric Raymond added a simple interactive statistics browser,
1556 invoked when the module is run as a script.
1557
1558- locale: fixed a problem in format().
1559
1560- webbrowser: made it work when the BROWSER environment variable has a
1561 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1562 KDE 2. Fixed some other nits.
1563
1564- unittest: changes to allow using a different exception than
1565 AssertionError, and added a few more function aliases. Some other
1566 small changes.
1567
1568- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1569
1570- asynchat: fixed a critical bug in asynchat that slipped through the
1571 2.1b2 release. Fixed another rare bug.
1572
1573- Fix some unqualified except: clauses (always a bad code example).
1574
1575XML
1576
1577- pyexpat: new API get_version_string().
1578
1579- Fixed some minidom bugs.
1580
1581Extensions
1582
1583- Fixed a core dump in _weakref. Removed the weakref.mapping()
1584 function (it adds nothing to the API).
1585
1586- Rationalized the use of header files in the readline module, to make
1587 it compile (albeit with some warnings) with the very recent readline
1588 4.2, without breaking for earlier versions.
1589
1590- Hopefully fixed a buffering problem in linuxaudiodev.
1591
1592- Attempted a fix to make the OpenSSL support in the socket module
1593 work again with pre-0.9.5 versions of OpenSSL.
1594
1595Tests
1596
1597- Added a test case for asynchat and asyncore.
1598
1599- Removed coupling between tests where one test failing could break
1600 another.
1601
1602Tools
1603
1604- Ping added an interactive help browser to pydoc, fixed some nits
1605 in the rest of the pydoc code, and added some features to his
1606 inspect module.
1607
1608- An updated python-mode.el version 4.1 which integrates Ken
1609 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1610 much nicer in XEmacs and Emacs. When stepping through your program
1611 with pdb, in either the shell window or the *Python* window, the
1612 source file and line will be tracked by an arrow. Very cool!
1613
1614- IDLE: syntax warnings in interactive mode are changed into errors.
1615
1616- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001617 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001618
1619- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001620
Barry Warsaw11e89c72001-04-11 20:37:57 +00001621
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001622What's New in Python 2.1 beta 2?
1623================================
1624
Guido van Rossum053ae352001-03-22 14:17:21 +00001625(Unlisted are many fixed bugs, more documentation, etc.)
1626
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001627Core language, builtins, and interpreter
1628
Guido van Rossum053ae352001-03-22 14:17:21 +00001629- The nested scopes work (enabled by "from __future__ import
1630 nested_scopes") is completed; in particular, the future now extends
1631 into code executed through exec, eval() and execfile(), and into the
1632 interactive interpreter.
1633
1634- When calling a base class method (e.g. BaseClass.__init__(self)),
1635 this is now allowed even if self is not strictly spoken a class
1636 instance (e.g. when using metaclasses or the Don Beaudry hook).
1637
1638- Slice objects are now comparable but not hashable; this prevents
1639 dict[:] from being accepted but meaningless.
1640
1641- Complex division is now calculated using less braindead algorithms.
1642 This doesn't change semantics except it's more likely to give useful
1643 results in extreme cases. Complex repr() now uses full precision
1644 like float repr().
1645
1646- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1647
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001648- It is illegal to assign to the name __debug__, which is set when the
1649 interpreter starts. It is effectively a compile-time constant.
1650
1651- A warning will be issued if a global statement for a variable
1652 follows a use or assignment of that variable.
1653
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001654Standard library
1655
Guido van Rossum053ae352001-03-22 14:17:21 +00001656- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1657 inspired by JUnit), is now part of the standard library. You now
1658 have a choice of two testing frameworks: unittest requires you to
1659 write testcases as separate code, doctest gathers them from
1660 docstrings. Both approaches have their advantages and
1661 disadvantages.
1662
1663- A new module Tix was added, which wraps the Tix extension library
1664 for Tk. With that module, it is not necessary to statically link
1665 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1666 require" command. See Demo/tix/.
1667
1668- tzparse.py is now obsolete.
1669
1670- In gzip.py, the seek() and tell() methods are removed -- they were
1671 non-functional anyway, and it's better if callers can test for their
1672 existence with hasattr().
1673
1674Python/C API
1675
1676- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1677 that's already in the dictionary during a PyDict_Next() iteration.
1678 This used to fail occasionally when a dictionary resize operation
1679 could be triggered that would rehash all the keys. All other
1680 modifications to the dictionary are still off-limits during a
1681 PyDict_Next() iteration!
1682
1683- New extended APIs related to passing compiler variables around.
1684
1685- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1686 implement isinstance() and issubclass().
1687
1688- Py_BuildValue() now has a "D" conversion to create a Python complex
1689 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001690
Fred Drake4e262a92001-03-22 18:26:47 +00001691- Extensions types which support weak references must now set the
1692 field allocated for the weak reference machinery to NULL themselves;
1693 this is done to avoid the cost of checking each object for having a
1694 weakly referencable type in PyObject_INIT(), since most types are
1695 not weakly referencable.
1696
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001697- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1698 free variables and cell variables to and from the frame's f_locals.
1699
1700- Variants of several functions defined in pythonrun.h have been added
1701 to support the nested_scopes future statement. The variants all end
1702 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1703 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1704 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001705 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001706
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001707Distutils
1708
1709- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1710 into the release tree.
1711
Tim Peters0e57abf2001-05-02 07:39:38 +00001712- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001713 (an uninstaller, more customization of the installer's display)
1714
1715- from Jack Jansen: added Mac-specific code to generate a dialog for
1716 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001717 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001718 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001719
1720- added 'platforms' and 'keywords' to the set of metadata that can be
1721 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001722
1723- applied patches from Jason Tishler to make the compiler class work with
1724 Cygwin.
1725
1726
Tim Peters2fe289a2001-03-01 22:19:38 +00001727What's New in Python 2.1 beta 1?
1728================================
Tim Petersd66595f2001-02-04 03:09:53 +00001729
1730Core language, builtins, and interpreter
1731
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001732- Following an outcry from the community about the amount of code
1733 broken by the nested scopes feature introduced in 2.1a2, we decided
1734 to make this feature optional, and to wait until Python 2.2 (or at
1735 least 6 months) to make it standard. The option can be enabled on a
1736 per-module basis by adding "from __future__ import nested_scopes" at
1737 the beginning of a module (before any other statements, but after
1738 comments and an optional docstring). See PEP 236 (Back to the
1739 __future__) for a description of the __future__ statement. PEP 227
1740 (Statically Nested Scopes) has been updated to reflect this change,
1741 and to clarify the semantics in a number of endcases.
1742
1743- The nested scopes code, when enabled, has been hardened, and most
1744 bugs and memory leaks in it have been fixed.
1745
1746- Compile-time warnings are now generated for a number of conditions
1747 that will break or change in meaning when nested scopes are enabled:
1748
1749 - Using "from...import *" or "exec" without in-clause in a function
1750 scope that also defines a lambda or nested function with one or
1751 more free (non-local) variables. The presence of the import* or
1752 bare exec makes it impossible for the compiler to determine the
1753 exact set of local variables in the outer scope, which makes it
1754 impossible to determine the bindings for free variables in the
1755 inner scope. To avoid the warning about import *, change it into
1756 an import of explicitly name object, or move the import* statement
1757 to the global scope; to avoid the warning about bare exec, use
1758 exec...in... (a good idea anyway -- there's a possibility that
1759 bare exec will be deprecated in the future).
1760
1761 - Use of a global variable in a nested scope with the same name as a
1762 local variable in a surrounding scope. This will change in
1763 meaning with nested scopes: the name in the inner scope will
1764 reference the variable in the outer scope rather than the global
1765 of the same name. To avoid the warning, either rename the outer
1766 variable, or use a global statement in the inner function.
1767
Neil Schemenauera35c6882001-02-27 04:45:05 +00001768- An optional object allocator has been included. This allocator is
1769 optimized for Python objects and should be faster and use less memory
1770 than the standard system allocator. It is not enabled by default
1771 because of possible thread safety problems. The allocator is only
1772 protected by the Python interpreter lock and it is possible that some
1773 extension modules require a thread safe allocator. The object
1774 allocator can be enabled by providing the "--with-pymalloc" option to
1775 configure.
1776
Tim Petersd66595f2001-02-04 03:09:53 +00001777Standard library
1778
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001779- pyexpat now detects the expat version if expat.h defines it. A
1780 number of additional handlers are provided, which are only available
1781 since expat 1.95. In addition, the methods SetParamEntityParsing and
1782 GetInputContext of Parser objects are available with 1.95.x
1783 only. Parser objects now provide the ordered_attributes and
1784 specified_attributes attributes. A new module expat.model was added,
1785 which offers a number of additional constants if 1.95.x is used.
1786
1787- xml.dom offers the new functions registerDOMImplementation and
1788 getDOMImplementation.
1789
1790- xml.dom.minidom offers a toprettyxml method. A number of DOM
1791 conformance issues have been resolved. In particular, Element now
1792 has an hasAttributes method, and the handling of namespaces was
1793 improved.
1794
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001795- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1796 getting information about live Python code, and pydoc.py, a module
1797 for interactively converting docstrings to HTML or text.
1798 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001799 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001800 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1801 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001802
Tim Peters1eff7962001-03-01 02:31:33 +00001803- New library module difflib.py, primarily packaging the SequenceMatcher
1804 class at the heart of the popular ndiff.py file-comparison tool.
1805
1806- doctest.py (a framework for verifying Python code examples in docstrings)
1807 is now part of the std library.
1808
Tim Petersd66595f2001-02-04 03:09:53 +00001809Windows changes
1810
Guido van Rossume3955a82001-03-02 14:05:59 +00001811- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1812 small GUI that lets you browse the module docstrings using your
1813 default web browser.
1814
Tim Peters1eff7962001-03-01 02:31:33 +00001815- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1816 Platforms) is implemented. See
1817
1818 http://python.sourceforge.net/peps/pep-0235.html
1819
1820 for full details, especially the "Current Lower-Left Semantics" section.
1821 The new Windows import rules are simpler than before:
1822
1823 A. If the PYTHONCASEOK environment variable exists, same as
1824 before: silently accept the first case-insensitive match of any
1825 kind; raise ImportError if none found.
1826
1827 B. Else search sys.path for the first case-sensitive match; raise
1828 ImportError if none found.
1829
1830 The same rules have been implented on other platforms with case-
1831 insensitive but case-preserving filesystems too (including Cygwin, and
1832 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001833
Tim Peters25a9ce32001-02-19 07:06:36 +00001834- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1835 what it's supposed to do (and does do under NT and 2000) via direct
1836 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001837 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001838 all Win9x systems before.
1839
Tim Peters1eff7962001-03-01 02:31:33 +00001840- Build: Subproject _test (effectively) renamed to _testcapi.
1841
Tim Peters2fe289a2001-03-01 22:19:38 +00001842New platforms
1843
1844- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1845 Thanks to Steven Majewski!
1846
1847- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1848 Tishler!
1849
Guido van Rossum9089b272001-03-02 06:49:50 +00001850- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1851 Schwertberger! See RISCOS/README for more information -- it seems
1852 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001853 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001854
Tim Peters25a9ce32001-02-19 07:06:36 +00001855
Tim Petersd7b5e882001-01-25 03:36:26 +00001856What's New in Python 2.1 alpha 2?
1857=================================
Tim Peters40ead762001-01-27 05:35:26 +00001858
Tim Petersd7b5e882001-01-25 03:36:26 +00001859Core language, builtins, and interpreter
1860
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001861- Scopes nest. If a name is used in a function or class, but is not
1862 local, the definition in the nearest enclosing function scope will
1863 be used. One consequence of this change is that lambda statements
1864 could reference variables in the namespaces where the lambda is
1865 defined. In some unusual cases, this change will break code.
1866
1867 In all previous version of Python, names were resolved in exactly
1868 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001869 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001870 function A is defined within a function B, the names bound in B are
1871 not visible in A. The new rules make names bound in B visible in A,
1872 unless A contains a name binding that hides the binding in B.
1873
1874 Section 4.1 of the reference manual describes the new scoping rules
1875 in detail. The test script in Lib/test/test_scope.py demonstrates
1876 some of the effects of the change.
1877
1878 The new rules will cause existing code to break if it defines nested
1879 functions where an outer function has local variables with the same
1880 name as globals or builtins used by the inner function. Example:
1881
1882 def munge(str):
1883 def helper(x):
1884 return str(x)
1885 if type(str) != type(''):
1886 str = helper(str)
1887 return str.strip()
1888
1889 Under the old rules, the name str in helper() is bound to the
1890 builtin function str(). Under the new rules, it will be bound to
1891 the argument named str and an error will occur when helper() is
1892 called.
1893
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001894- The compiler will report a SyntaxError if "from ... import *" occurs
1895 in a function or class scope. The language reference has documented
1896 that this case is illegal, but the compiler never checked for it.
1897 The recent introduction of nested scope makes the meaning of this
1898 form of name binding ambiguous. In a future release, the compiler
1899 may allow this form when there is no possibility of ambiguity.
1900
Tim Peters40ead762001-01-27 05:35:26 +00001901- repr(string) is easier to read, now using hex escapes instead of octal,
1902 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1903
1904 >>> "\texample \r\n" + chr(0) + chr(255)
1905 '\texample \r\n\x00\xff' # in 2.1
1906 '\011example \015\012\000\377' # in 2.0
1907
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001908- Functions are now compared and hashed by identity, not by value, since
1909 the func_code attribute is writable.
1910
Fred Drakefb9d7122001-02-01 20:00:40 +00001911- Weak references (PEP 205) have been added. This involves a few
1912 changes in the core, an extension module (_weakref), and a Python
1913 module (weakref). The weakref module is the public interface. It
1914 includes support for "explicit" weak references, proxy objects, and
1915 mappings with weakly held values.
1916
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001917- A 'continue' statement can now appear in a try block within the body
1918 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001919 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001920
Tim Petersd7b5e882001-01-25 03:36:26 +00001921Standard library
1922
Barry Warsaw30dbd142001-01-31 22:14:01 +00001923- mailbox.py now has a new class, PortableUnixMailbox which is
1924 identical to UnixMailbox but uses a more portable scheme for
1925 determining From_ separators. Also, the constructors for all the
1926 classes in this module have a new optional `factory' argument, which
1927 is a callable used when new message classes must be instantiated by
1928 the next() method.
1929
Tim Petersd7b5e882001-01-25 03:36:26 +00001930- random.py is now self-contained, and offers all the functionality of
1931 the now-deprecated whrandom.py. See the docs for details. random.py
1932 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001933 and restoring the internal state of the generator; and jumpahead(n),
1934 for quickly forcing the internal state to be the same as if n calls to
1935 random() had been made. The latter is particularly useful for multi-
1936 threaded programs, creating one instance of the random.Random() class for
1937 each thread, then using .jumpahead() to force each instance to use a
1938 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001939
Tim Peters0de88fc2001-02-01 04:59:18 +00001940- random.py's seed() function is new. For bit-for-bit compatibility with
1941 prior releases, use the whseed function instead. The new seed function
1942 addresses two problems: (1) The old function couldn't produce more than
1943 about 2**24 distinct internal states; the new one about 2**45 (the best
1944 that can be done in the Wichmann-Hill generator). (2) The old function
1945 sometimes produced identical internal states when passed distinct
1946 integers, and there was no simple way to predict when that would happen;
1947 the new one guarantees to produce distinct internal states for all
1948 arguments in [0, 27814431486576L).
1949
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001950- The socket module now supports raw packets on Linux. The socket
1951 family is AF_PACKET.
1952
Tim Peters9ea17ac2001-02-02 05:57:15 +00001953- test_capi.py is a start at running tests of the Python C API. The tests
1954 are implemented by the new Modules/_testmodule.c.
1955
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001956- A new extension module, _symtable, provides provisional access to the
1957 internal symbol table used by the Python compiler. A higher-level
1958 interface will be added on top of _symtable in a future release.
1959
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00001960- Removed the obsolete soundex module.
1961
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001962- xml.dom.minidom now uses the standard DOM exceptions. Node supports
1963 the isSameNode method; NamedNodeMap the get method.
1964
1965- xml.sax.expatreader supports the lexical handler property; it
1966 generates comment, startCDATA, and endCDATA events.
1967
Tim Petersee826f82001-01-31 19:39:44 +00001968Windows changes
1969
1970- Build procedure: the zlib project is built in a different way that
1971 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00001972 the zlib binary used. See PCbuild\readme.txt for details. Your old
1973 zlib-related directories can be deleted; you'll need to download fresh
1974 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00001975
Tim Peters9ea17ac2001-02-02 05:57:15 +00001976- Build: New subproject _test for the benefit of test_capi.py (see above).
1977
Tim Petersb16c56f2001-02-02 21:24:51 +00001978- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
1979 interface to some Python compiler internals).
1980
1981- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00001982 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00001983
Tim Petersa3a3a032000-11-30 05:22:44 +00001984What's New in Python 2.1 alpha 1?
1985=================================
1986
1987Core language, builtins, and interpreter
1988
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00001989- There is a new Unicode companion to the PyObject_Str() API
1990 called PyObject_Unicode(). It behaves in the same way as the
1991 former, but assures that the returned value is an Unicode object
1992 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00001993
Guido van Rossumf98eda02001-01-17 15:54:45 +00001994- The comparison operators support "rich comparison overloading" (PEP
1995 207). C extension types can provide a rich comparison function in
1996 the new tp_richcompare slot in the type object. The cmp() function
1997 and the C function PyObject_Compare() first try the new rich
1998 comparison operators before trying the old 3-way comparison. There
1999 is also a new C API PyObject_RichCompare() (which also falls back on
2000 the old 3-way comparison, but does not constrain the outcome of the
2001 rich comparison to a Boolean result).
2002
2003 The rich comparison function takes two objects (at least one of
2004 which is guaranteed to have the type that provided the function) and
2005 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2006 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2007 object, which may be NotImplemented (in which case the tp_compare
2008 slot function is used as a fallback, if defined).
2009
2010 Classes can overload individual comparison operators by defining one
2011 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002012 __ge__. There are no explicit "reflected argument" versions of
2013 these; instead, __lt__ and __gt__ are each other's reflection,
2014 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2015 reflection (similar at the C level). No other implications are
2016 made; in particular, Python does not assume that == is the Boolean
2017 inverse of !=, or that < is the Boolean inverse of >=. This makes
2018 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002019
2020 Classes or types that want to implement (in)equality tests but not
2021 the ordering operators (i.e. unordered types) should implement ==
2022 and !=, and raise an error for the ordering operators.
2023
Guido van Rossuma88479f2001-01-18 14:28:08 +00002024 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002025 Boolean; e.g. a matrix type might want to return a matrix of bits
2026 for A < B, giving elementwise comparisons. Such types should ensure
2027 that any interpretation of their value in a Boolean context raises
2028 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2029 at the C level) to always raise an exception.
2030
Guido van Rossuma88479f2001-01-18 14:28:08 +00002031- Complex numbers use rich comparisons to define == and != but raise
2032 an exception for <, <=, > and >=. Unfortunately, this also means
2033 that cmp() of two complex numbers raises an exception when the two
2034 numbers differ. Since it is not mathematically meaningful to compare
2035 complex numbers except for equality, I hope that this doesn't break
2036 too much code.
2037
Tim Peters3389f192001-02-18 08:48:49 +00002038- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002039 not defined by the language, other than that it's arbitrary but
2040 consistent (see the Reference Manual). An implementation detail changed
2041 in 2.1a1 such that None now compares less than any other object. Code
2042 relying on this new behavior (like code that relied on the previous
2043 behavior) does so at its own risk.
2044
Barry Warsaw573b5412001-01-15 20:43:18 +00002045- Functions and methods now support getting and setting arbitrarily
2046 named attributes (PEP 232). Functions have a new __dict__
2047 (a.k.a. func_dict) which hold the function attributes. Methods get
2048 and set attributes on their underlying im_func. It is a TypeError
2049 to set an attribute on a bound method.
2050
Guido van Rossum051e3352001-01-15 19:11:10 +00002051- The xrange() object implementation has been improved so that
2052 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2053 limitation that in this case len(xrange(sys.maxint)) can't be
2054 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2055 work fine as long as the index i doesn't actually reach 2**31.
2056 (Python uses regular ints for sequence and string indices; fixing
2057 that is much more work.)
2058
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002059- Two changes to from...import:
2060
Guido van Rossumba381232001-02-03 15:06:40 +00002061 1) "from M import X" now works even if (after loading module M)
2062 sys.modules['M'] is not a real module; it's basically a getattr()
2063 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002064
2065 2) "from M import *" now looks for M.__all__ to decide which names to
2066 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2067 filters out names starting with '_' as before. Whether or not
2068 __all__ exists, there's no restriction on the type of M.
2069
Guido van Rossumf61f1662001-01-10 20:13:55 +00002070- File objects have a new method, xreadlines(). This is the fastest
2071 way to iterate over all lines in a file:
2072
2073 for line in file.xreadlines():
2074 ...do something to line...
2075
2076 See the xreadlines module (mentioned below) for how to do this for
2077 other file-like objects.
2078
2079- Even if you don't use file.xreadlines(), you may expect a speedup on
2080 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002081 quite a bit in platform-specific ways: on systems (like Linux) that
2082 support flockfile(), getc_unlocked(), and funlockfile(), those are
2083 used by default. On systems (like Windows) without getc_unlocked(),
2084 a complicated (but still thread-safe) method using fgets() is used by
2085 default.
2086
Tim Petersd52269b2001-01-25 06:23:18 +00002087 You can force use of the fgets() method by #define'ing
2088 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002089 getc_unlocked()).
2090
Tim Petersd52269b2001-01-25 06:23:18 +00002091 You can force fgets() not to be used by #define'ing
2092 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002093 test_bufio.py fails -- and let us know if it does!).
2094
2095- In addition, the fileinput module, while still slower than the other
2096 methods on most platforms, has been sped up too, by using
2097 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002098
2099- Support for run-time warnings has been added, including a new
2100 command line option (-W) to specify the disposition of warnings.
2101 See the description of the warnings module below.
2102
2103- Extensive changes have been made to the coercion code. This mostly
2104 affects extension modules (which can now implement mixed-type
2105 numerical operators without having to use coercion), but
2106 occasionally, in boundary cases the coercion semantics have changed
2107 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002108 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002109 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002110 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002111
Guido van Rossumf98eda02001-01-17 15:54:45 +00002112- In connection with the coercion changes, a new built-in singleton
2113 object, NotImplemented is defined. This can be returned for
2114 operations that wish to indicate they are not implemented for a
2115 particular combination of arguments. From C, this is
2116 Py_NotImplemented.
2117
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002118- The interpreter accepts now bytecode files on the command line even
2119 if they do not have a .pyc or .pyo extension. On Linux, after executing
2120
Martin v. Löwise214baa2001-02-04 22:37:56 +00002121import imp,sys,string
2122magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2123reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2124open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002125
2126 any byte code file can be used as an executable (i.e. as an argument
2127 to execve(2)).
2128
Tim Peters9940b802000-12-01 07:59:35 +00002129- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002130 character. In 1.6 and earlier, they never produced a sign,
2131 and raised an error if the value of the long was too large
2132 to fit in a Python int. In 2.0, they produced a sign if and
2133 only if too large to fit in an int. This was inconsistent
2134 across platforms (because the size of an int varies across
2135 platforms), and inconsistent with hex() and oct(). Example:
2136
2137 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002138 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002139 'ffffffbe' # in 2.0 and before, on 32-bit machines
2140 >>> hex(-0x42L)
2141 '-0x42L' # in all versions of Python
2142
Tim Peters9940b802000-12-01 07:59:35 +00002143 The behavior of %d formats for negative Python longs remains
2144 the same as in 2.0 (although in 1.6 and before, they raised
2145 an error if the long didn't fit in a Python int).
2146
2147 %u formats don't make sense for Python longs, but are allowed
2148 and treated the same as %d in 2.1. In 2.0, a negative long
2149 formatted via %u produced a sign if and only if too large to
2150 fit in an int. In 1.6 and earlier, a negative long formatted
2151 via %u raised an error if it was too big to fit in an int.
2152
Guido van Rossum3661d392000-12-12 22:10:31 +00002153- Dictionary objects have an odd new method, popitem(). This removes
2154 an arbitrary item from the dictionary and returns it (in the form of
2155 a (key, value) pair). This can be useful for algorithms that use a
2156 dictionary as a bag of "to do" items and repeatedly need to pick one
2157 item. Such algorithms normally end up running in quadratic time;
2158 using popitem() they can usually be made to run in linear time.
2159
Tim Peters36cdad12000-12-29 02:06:45 +00002160Standard library
2161
Thomas Woutersfe385252001-01-19 23:16:56 +00002162- In the time module, the time argument to the functions strftime,
2163 localtime, gmtime, asctime and ctime is now optional, defaulting to
2164 the current time (in the local timezone).
2165
Guido van Rossumda91f222001-01-15 16:36:08 +00002166- The ftplib module now defaults to passive mode, which is deemed a
2167 more useful default given that clients are often inside firewalls
2168 these days. Note that this could break if ftplib is used to connect
2169 to a *server* that is inside a firewall, from outside; this is
2170 expected to be a very rare situation. To fix that, you can call
2171 ftp.set_pasv(0).
2172
Martin v. Löwis10a27872001-01-13 09:54:41 +00002173- The module site now treats .pth files not only for path configuration,
2174 but also supports extensions to the initialization code: Lines starting
2175 with import are executed.
2176
Guido van Rossumf61f1662001-01-10 20:13:55 +00002177- There's a new module, warnings, which implements a mechanism for
2178 issuing and filtering warnings. There are some new built-in
2179 exceptions that serve as warning categories, and a new command line
2180 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2181 turns warnings into errors). warnings.warn(message[, category])
2182 issues a warning message; this can also be called from C as
2183 PyErr_Warn(category, message).
2184
2185- A new module xreadlines was added. This exports a single factory
2186 function, xreadlines(). The intention is that this code is the
2187 absolutely fastest way to iterate over all lines in an open
2188 file(-like) object:
2189
2190 import xreadlines
2191 for line in xreadlines.xreadlines(file):
2192 ...do something to line...
2193
2194 This is equivalent to the previous the speed record holder using
2195 file.readlines(sizehint). Note that if file is a real file object
2196 (as opposed to a file-like object), this is equivalent:
2197
2198 for line in file.xreadlines():
2199 ...do something to line...
2200
Tim Peters36cdad12000-12-29 02:06:45 +00002201- The bisect module has new functions bisect_left, insort_left,
2202 bisect_right and insort_right. The old names bisect and insort
2203 are now aliases for bisect_right and insort_right. XXX_right
2204 and XXX_left methods differ in what happens when the new element
2205 compares equal to one or more elements already in the list: the
2206 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002207 right. Code that doesn't care where equal elements end up should
2208 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002209
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002210- The new curses.panel module wraps the panel library that forms part
2211 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2212
Guido van Rossumf61f1662001-01-10 20:13:55 +00002213- The SocketServer module now sets the allow_reuse_address flag by
2214 default in the TCPServer class.
2215
2216- A new function, sys._getframe(), returns the stack frame pointer of
2217 the caller. This is intended only as a building block for
2218 higher-level mechanisms such as string interpolation.
2219
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002220- The pyexpat module supports a number of new handlers, which are
2221 available only in expat 1.2. If invocation of a callback fails, it
2222 will report an additional frame in the traceback. Parser objects
2223 participate now in garbage collection. If expat reports an unknown
2224 encoding, pyexpat will try to use a Python codec; that works only
2225 for single-byte charsets. The parser type objects is exposed as
2226 XMLParserObject.
2227
2228- xml.dom now offers standard definitions for symbolic node type and
2229 exception code constants, and a hierarchy of DOM exceptions. minidom
2230 was adjusted to use them.
2231
2232- The conformance of xml.dom.minidom to the DOM specification was
2233 improved. It detects a number of additional error cases; the
2234 previous/next relationship works even when the tree is modified;
2235 Node supports the normalize() method; NamedNodeMap, DocumentType and
2236 DOMImplementation classes were added; Element supports the
2237 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2238 method.
2239
Guido van Rossumf61f1662001-01-10 20:13:55 +00002240Build issues
2241
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002242- For Unix (and Unix-compatible) builds, configuration and building of
2243 extension modules is now greatly automated. Rather than having to
2244 edit the Modules/Setup file to indicate which modules should be
2245 built and where their include files and libraries are, a
2246 distutils-based setup.py script now takes care of building most
2247 extension modules. All extension modules built this way are built
2248 as shared libraries. Only a few modules that must be linked
2249 statically are still listed in the Setup file; you won't need to
2250 edit their configuration.
2251
2252- Python should now build out of the box on Cygwin. If it doesn't,
2253 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002254
2255- Python now always uses its own (renamed) implementation of getopt()
2256 -- there's too much variation among C library getopt()
2257 implementations.
2258
2259- C++ compilers are better supported; the CXX macro is always set to a
2260 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002261
Tim Petersd92dfe02000-12-12 01:18:41 +00002262Windows changes
2263
2264- select module: By default under Windows, a select() call
2265 can specify no more than 64 sockets. Python now boosts
2266 this Microsoft default to 512. If you need even more than
2267 that, see the MS docs (you'll need to #define FD_SETSIZE
2268 and recompile Python from source).
2269
Guido van Rossumf61f1662001-01-10 20:13:55 +00002270- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2271 subdirectory is no more!
2272
Tim Petersa3a3a032000-11-30 05:22:44 +00002273
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002274What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002275=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002276
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002277Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002278changes are in the file HISTORY. If you are making the jump directly
2279from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2280HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002281
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002282Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2283the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2284http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002285
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002286--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002287
2288======================================================================
2289
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002290What's new in 2.0 (since release candidate 1)?
2291==============================================
2292
2293Standard library
2294
2295- The copy_reg module was modified to clarify its intended use: to
2296 register pickle support for extension types, not for classes.
2297 pickle() will raise a TypeError if it is passed a class.
2298
2299- Fixed a bug in gettext's "normalize and expand" code that prevented
2300 it from finding an existing .mo file.
2301
2302- Restored support for HTTP/0.9 servers in httplib.
2303
Tim Peters989b7b92000-10-16 20:24:53 +00002304- The math module was changed to stop raising OverflowError in case of
2305 underflow, and return 0 instead in underflow cases. Whether Python
2306 used to raise OverflowError in case of underflow was platform-
2307 dependent (it did when the platform math library set errno to ERANGE
2308 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002309
2310- Fixed a bug in StringIO that occurred when the file position was not
2311 at the end of the file and write() was called with enough data to
2312 extend past the end of the file.
2313
2314- Fixed a bug that caused Tkinter error messages to get lost on
2315 Windows. The bug was fixed by replacing direct use of
2316 interp->result with Tcl_GetStringResult(interp).
2317
2318- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2319 redirect response.
2320
2321- Several changes were made to distutils: Some debugging code was
2322 removed from util. Fixed the installer used when an external zip
2323 program (like WinZip) is not found; the source code for this
2324 installer is in Misc/distutils. check_lib() was modified to behave
2325 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2326 test for whether installed modules are on sys.path was changed to
2327 use both normcase() and normpath().
2328
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002329- Several minor bugs were fixed in the xml package (the minidom,
2330 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002331
2332- The regression test driver (regrtest.py) behavior when invoked with
2333 -l changed: It now reports a count of objects that are recognized as
2334 garbage but not freed by the garbage collector.
2335
Tim Peters989b7b92000-10-16 20:24:53 +00002336- The regression test for the math module was changed to test
2337 exceptional behavior when the test is run in verbose mode. Python
2338 cannot yet guarantee consistent exception behavior across platforms,
2339 so the exception part of test_math is run only in verbose mode, and
2340 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002341
2342Internals
2343
2344- PyOS_CheckStack() has been disabled on Win64, where it caused
2345 test_sre to fail.
2346
2347Build issues
2348
2349- Changed compiler flags, so that gcc is always invoked with -Wall and
2350 -Wstrict-prototypes. Users compiling Python with GCC should see
2351 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002352 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002353 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002354
Tim Petersa3a3a032000-11-30 05:22:44 +00002355- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002356
2357Tools and other miscellany
2358
2359- The compiler in Tools/compiler was updated to support the new
2360 language features introduced in 2.0: extended print statement, list
2361 comprehensions, and augmented assignments. The new compiler should
2362 also be backwards compatible with Python 1.5.2; the compiler will
2363 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002364 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002365
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002366What's new in 2.0 release candidate 1 (since beta 2)?
2367=====================================================
2368
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002369What is release candidate 1?
2370
2371We believe that release candidate 1 will fix all known bugs that we
2372intend to fix for the 2.0 final release. This release should be a bit
2373more stable than the previous betas. We would like to see even more
2374widespread testing before the final release, so we are producing this
2375release candidate. The final release will be exactly the same unless
2376any show-stopping (or brown bag) bugs are found by testers of the
2377release candidate.
2378
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002379All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002380to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002381
2382Core language, builtins, and interpreter
2383
2384- A bug that caused crashes when __coerce__ was used with augmented
2385 assignment, e.g. +=, was fixed.
2386
2387- Raise ZeroDivisionError when raising zero to a negative number,
2388 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2389 power operator and the result of math.pow(0.0, -2.0) will vary by
2390 platform. On Linux, it raises a ValueError.
2391
2392- A bug in Unicode string interpolation was fixed that occasionally
2393 caused errors with formats including "%%". For example, the
2394 following expression "%% %s" % u"abc" no longer raises a TypeError.
2395
2396- Compilation of deeply nested expressions raises MemoryError instead
2397 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2398
2399- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2400 rendering them useless. They are now written in binary mode again.
2401
2402Standard library
2403
2404- Keyword arguments are now accepted for most pattern and match object
2405 methods in SRE, the standard regular expression engine.
2406
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002407- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002408 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002409
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002410- Several bugs in the Unicode handling and error handling in _tkinter
2411 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002412
2413- Fix memory management errors in Merge() and Tkapp_Call() routines.
2414
2415- Several changes were made to cStringIO to make it compatible with
2416 the file-like object interface and with StringIO. If operations are
2417 performed on a closed object, an exception is raised. The truncate
2418 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002419 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002420
2421- There were many changes made to the linuxaudiodev module and its
2422 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002423 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002424
2425 Note that this module is named poorly, because it should work
2426 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002427 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002428
2429 The module now raises exceptions when errors occur instead of
2430 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2431 audio) and defines a getptr() method that calls the
2432 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2433
2434- The library_version attribute, introduced in an earlier beta, was
2435 removed because it can not be supported with early versions of the C
2436 readline library, which provides no way to determine the version at
2437 compile-time.
2438
2439- The binascii module is now enabled on Win64.
2440
Tim Peters46446d62000-10-09 21:19:31 +00002441- tokenize.py no longer suffers "recursion depth" errors when parsing
2442 programs with very long string literals.
2443
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002444Internals
2445
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002446- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002447 which is called when the interpreter starts up to determine where
2448 the standard library is installed. These vulnerabilities affect all
2449 previous versions of Python and can be exploited by setting very
2450 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2451 setuid Python script, although use of the wrapper in
2452 Misc/setuid-prog.c will eliminate the vulnerability.
2453
2454- Fixed garbage collection bugs in instance creation that were
2455 triggered when errors occurred during initialization. The solution,
2456 applied in cPickle and in PyInstance_New(), is to call
2457 PyObject_GC_Init() after the initialization of the object's
2458 container attributes is complete.
2459
2460- pyexpat adds definitions of PyModule_AddStringConstant and
2461 PyModule_AddObject if the Python version is less than 2.0, which
2462 provides compatibility with PyXML on Python 1.5.2.
2463
2464- If the platform has a bogus definition for LONG_BIT (the number of
2465 bits in a long), an error will be reported at compile time.
2466
2467- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2468 collection crashes and possibly other, unreported crashes.
2469
2470- Fixed a memory leak in _PyUnicode_Fini().
2471
2472Build issues
2473
2474- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002475 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002476 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002477
2478- The mmap.PAGESIZE constant is now initialized using sysconf when
2479 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2480
2481- The md5 file should now compile on all platforms.
2482
2483- The select module now compiles on platforms that do not define
2484 POLLRDNORM and related constants.
2485
2486- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002487 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002488
Jeremy Hylton10921202000-10-09 18:34:12 +00002489- BeOS: A number of changes were made to the build and installation
2490 process. ar-fake now operates on a directory of object files.
2491 dl_export.h is gone, and its macros now appear on the mwcc command
2492 line during build on PPC BeOS.
2493
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002494- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002495 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002496
2497- Cygwin: Support for shared libraries, Tkinter, and sockets.
2498
2499- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2500
2501Tools and other miscellany
2502
2503- Removed debugging prints from main used with freeze.
2504
Tim Peters46446d62000-10-09 21:19:31 +00002505- IDLE auto-indent no longer crashes when it encounters Unicode
2506 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002507
2508What's new in 2.0 beta 2 (since beta 1)?
2509========================================
2510
2511Core language, builtins, and interpreter
2512
Tim Peters482c0212000-09-26 06:33:09 +00002513- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002514 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002515
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002516- Add -h and -V command line options to print the usage message and
2517 Python version number and exit immediately.
2518
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002519- eval() and exec accept Unicode objects as code parameters.
2520
2521- getattr() and setattr() now also accept Unicode objects for the
2522 attribute name, which are converted to strings using the default
2523 encoding before lookup.
2524
2525- Multiplication on string and Unicode now does proper bounds
2526 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2527 string is too long."
2528
2529- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002530 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002531
Jeremy Hylton1b618592000-09-26 05:32:36 +00002532
2533Standard library and extensions
2534
Guido van Rossum5b08f132001-04-16 02:05:23 +00002535- socket module: the OpenSSL code now adds support for RAND_status()
2536 and EGD (Entropy Gathering Device).
2537
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002538- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002539 argument checking; it still takes no arguments.
2540
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002541- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002542
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002543- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002544
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002545- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002546
2547- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002548 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002549
2550- copy: Copy Unicode objects atomically.
2551
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002552- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002553
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002554- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002555
Fred Drake67233bc2000-09-26 16:40:27 +00002556- dbm: Add get() and setdefault() methods to dbm object. Add constant
2557 `library' to module that names the library used. Added doc strings
2558 and method names to error messages. Uses configure to determine
2559 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2560 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002561
2562- distutils: Update to version 0.9.3.
2563
2564- dl: Add several dl.RTLD_ constants.
2565
2566- fpectl: Now supported on FreeBSD.
2567
2568- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2569 found by the collector will be saved in gc.garbage. This is useful
2570 for debugging a program that creates reference cycles.
2571
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002572- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002573 of HTTP class. Do not close socket on zero-length response. Do not
2574 crash when server sends invalid content-length header.
2575
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002576- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002577
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002578- marshal: When reading a short, sign-extend on platforms where shorts
2579 are bigger than 16 bits. When reading a long, repair the unportable
2580 sign extension that was being done for 64-bit machines. (It assumed
2581 that signed right shift sign-extends.)
2582
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002583- operator: Add contains(), invert(), __invert__() as aliases for
2584 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002585
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002586- os: Add support for popen2() and popen3() on all platforms where
2587 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002588
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002589- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002590 clicking on a file in Explorer (or passing the file name to the
2591 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002592
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002593- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002594 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002595
2596- pickle: Now raises ValueError when an invalid pickle that contains
2597 a non-string repr where a string repr was expected. This behavior
2598 matches cPickle.
2599
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002600- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002601
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002602- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002603
2604- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002605 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002606 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002607
2608- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002609 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002610
2611- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002612 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002613 few cycles during startup since the first call to
2614 setdefaultencoding() will initialize the codec registry and the
2615 encodings package.
2616
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002617- socket: Support for size hint in readlines() method of object returned
2618 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002619
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002620- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002621 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002622 is followed by whitespace.
2623
Tim Petersa3a3a032000-11-30 05:22:44 +00002624- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002625
2626- struct: Check ranges for bytes and shorts.
2627
2628- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002629 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002630
2631- Tkinter: Image objects are now guaranteed to have unique ids. Set
2632 event.delta to zero if Tk version doesn't support mousewheel.
2633 Removed some debugging prints.
2634
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002635- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002636
Fred Drake67233bc2000-09-26 16:40:27 +00002637- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002638 which works around a bug in Norton AntiVirus 2000 that leads directly
2639 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002640
2641- xml: New version detection code allows PyXML to override standard
2642 XML package if PyXML version is greater than 0.6.1.
2643
Fred Drake64bb3802000-09-26 16:21:35 +00002644- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2645 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2646 tree only for nodes which are sufficiently interesting to a specific
2647 application. Does not provide the HTML-specific extensions. Still
2648 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002649
Fred Drake64bb3802000-09-26 16:21:35 +00002650- xml.sax: SAX 2 support for Python, including all the handler
2651 interfaces needed to process XML 1.0 compliant XML. Some
2652 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002653
Fred Drake64bb3802000-09-26 16:21:35 +00002654- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2655 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002656
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002657
Jeremy Hylton1b618592000-09-26 05:32:36 +00002658C API
2659
2660- Add three new convenience functions for module initialization --
2661 PyModule_AddObject(), PyModule_AddIntConstant(), and
2662 PyModule_AddStringConstant().
2663
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002664- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002665 removed and add #error to Python.h if NULL isn't defined after
2666 #include of stdio.h.
2667
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002668- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002669 backwards compatibility (at the source level) with old extensions.
2670
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002671- A wrapper API was added for signal() and sigaction(). Instead of
2672 either function, always use PyOS_getsig() to get a signal handler
2673 and PyOS_setsig() to set one. A new convenience typedef
2674 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002675
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002676- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002677 internal data buffer and size of a string object -- or the default
2678 encoded version of a Unicode object.
2679
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002680- PyString_Size() and PyString_AsString() accept Unicode objects.
2681
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002682- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002683 exists). INT_MAX and LONG_MAX will always be defined, even if
2684 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002686- PyFloat_FromString takes a second argument, pend, that was
2687 effectively useless. It is now officially useless but preserved for
2688 backwards compatibility. If the pend argument is not NULL, *pend is
2689 set to NULL.
2690
2691- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2692 for the attribute name. See note on getattr() above.
2693
2694- A few bug fixes to argument processing for Unicode.
2695 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2696 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2697 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002698 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002699
2700- Py_BuildValue accepts B format (for bgen-generated code).
2701
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002702
Jeremy Hylton1b618592000-09-26 05:32:36 +00002703Internals
2704
2705- On Unix, fix code for finding Python installation directory so that
2706 it works when argv[0] is a relative path.
2707
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002708- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002709 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002710 rather than by generating a copy of the object.
2711
Tim Peters482c0212000-09-26 06:33:09 +00002712- Several of the internal Unicode tables are much smaller now, and
2713 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002714
Jeremy Hylton97693b02000-09-26 17:42:51 +00002715- In the garbage collector: Fixed bug in collection of tuples. Fixed
2716 bug that caused some instances to be removed from the container set
2717 while they were still live. Fixed parsing in gc.set_debug() for
2718 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002719
2720- Fixed refcount problem in instance deallocation that only occurred
2721 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2722
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002723- On Windows, getpythonregpath is now protected against null data in
2724 registry key.
2725
2726- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002727 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002728
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002729
Jeremy Hylton1b618592000-09-26 05:32:36 +00002730Build and platform-specific issues
2731
2732- Better support of GNU Pth via --with-pth configure option.
2733
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002734- Python/C API now properly exposed to dynamically-loaded extension
2735 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002736
2737- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2738 Don't define MS_SYNC to be zero when it is undefined. Added missing
2739 prototypes in posixmodule.c.
2740
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002741- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002742 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002743
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002744- Fix largefile support on older NetBSD systems and OpenBSD by adding
2745 define for TELL64.
2746
2747
2748Tools and other miscellany
2749
2750- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2751
2752- freeze: The modulefinder now works with 2.0 opcodes.
2753
Tim Petersa3a3a032000-11-30 05:22:44 +00002754- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002755 Move hackery of sys.argv until after the Tk instance has been
2756 created, which allows the application-specific Tkinter
2757 initialization to be executed if present; also pass an explicit
2758 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002759
Jeremy Hylton1b618592000-09-26 05:32:36 +00002760
2761What's new in 2.0 beta 1?
2762=========================
2763
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002764Source Incompatibilities
2765------------------------
2766
2767None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2768such as single-argument append(), connect() and bind(), and changes to
2769str(long) and repr(float).
2770
2771
2772Binary Incompatibilities
2773------------------------
2774
2775- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2776with Python 2.0; these extensions will have to be rebuilt for Python
27772.0.
2778
2779- On Windows, attempting to import a third party extension built for
2780Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2781can do about this. Check your PYTHONPATH environment variable!
2782
2783- Python bytecode files (*.pyc and *.pyo) are not compatible between
2784releases.
2785
2786
2787Overview of Changes Since 1.6
2788-----------------------------
2789
2790There are many new modules (including brand new XML support through
2791the xml package, and i18n support through the gettext module); a list
2792of all new modules is included below. Lots of bugs have been fixed.
2793
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002794The process for making major new changes to the language has changed
2795since Python 1.6. Enhancements must now be documented by a Python
2796Enhancement Proposal (PEP) before they can be accepted.
2797
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002798There are several important syntax enhancements, described in more
2799detail below:
2800
2801 - Augmented assignment, e.g. x += 1
2802
2803 - List comprehensions, e.g. [x**2 for x in range(10)]
2804
2805 - Extended import statement, e.g. import Module as Name
2806
2807 - Extended print statement, e.g. print >> file, "Hello"
2808
2809Other important changes:
2810
2811 - Optional collection of cyclical garbage
2812
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002813Python Enhancement Proposal (PEP)
2814---------------------------------
2815
2816PEP stands for Python Enhancement Proposal. A PEP is a design
2817document providing information to the Python community, or describing
2818a new feature for Python. The PEP should provide a concise technical
2819specification of the feature and a rationale for the feature.
2820
2821We intend PEPs to be the primary mechanisms for proposing new
2822features, for collecting community input on an issue, and for
2823documenting the design decisions that have gone into Python. The PEP
2824author is responsible for building consensus within the community and
2825documenting dissenting opinions.
2826
2827The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002828
2829Augmented Assignment
2830--------------------
2831
2832This must have been the most-requested feature of the past years!
2833Eleven new assignment operators were added:
2834
Guido van Rossume905e952000-09-05 12:42:46 +00002835 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002836
2837For example,
2838
2839 A += B
2840
2841is similar to
2842
2843 A = A + B
2844
2845except that A is evaluated only once (relevant when A is something
2846like dict[index].attr).
2847
2848However, if A is a mutable object, A may be modified in place. Thus,
2849if A is a number or a string, A += B has the same effect as A = A+B
2850(except A is only evaluated once); but if a is a list, A += B has the
2851same effect as A.extend(B)!
2852
2853Classes and built-in object types can override the new operators in
2854order to implement the in-place behavior; the not-in-place behavior is
2855used automatically as a fallback when an object doesn't implement the
2856in-place behavior. For classes, the method name is derived from the
2857method name for the corresponding not-in-place operator by inserting
2858an 'i' in front of the name, e.g. __iadd__ implements in-place
2859__add__.
2860
2861Augmented assignment was implemented by Thomas Wouters.
2862
2863
2864List Comprehensions
2865-------------------
2866
2867This is a flexible new notation for lists whose elements are computed
2868from another list (or lists). The simplest form is:
2869
2870 [<expression> for <variable> in <sequence>]
2871
Guido van Rossum56db0952000-09-06 23:34:25 +00002872For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002873This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002874
2875You can also add a condition:
2876
2877 [<expression> for <variable> in <sequence> if <condition>]
2878
2879For example, [w for w in words if w == w.lower()] would yield the list
2880of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002881than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002882
2883You can also have nested for loops and more than one 'if' clause. For
2884example, here's a function that flattens a sequence of sequences::
2885
2886 def flatten(seq):
2887 return [x for subseq in seq for x in subseq]
2888
2889 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2890
2891This prints
2892
2893 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2894
2895List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002896Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002897
2898
2899Extended Import Statement
2900-------------------------
2901
2902Many people have asked for a way to import a module under a different
2903name. This can be accomplished like this:
2904
2905 import foo
2906 bar = foo
2907 del foo
2908
2909but this common idiom gets old quickly. A simple extension of the
2910import statement now allows this to be written as follows:
2911
2912 import foo as bar
2913
2914There's also a variant for 'from ... import':
2915
2916 from foo import bar as spam
2917
2918This also works with packages; e.g. you can write this:
2919
2920 import test.regrtest as regrtest
2921
2922Note that 'as' is not a new keyword -- it is recognized only in this
2923context (this is only possible because the syntax for the import
2924statement doesn't involve expressions).
2925
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002926Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002927
2928
2929Extended Print Statement
2930------------------------
2931
2932Easily the most controversial new feature, this extension to the print
2933statement adds an option to make the output go to a different file
2934than the default sys.stdout.
2935
2936For example, to write an error message to sys.stderr, you can now
2937write:
2938
2939 print >> sys.stderr, "Error: bad dog!"
2940
2941As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002942evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002943
2944 print >> None, "Hello world"
2945
2946is equivalent to
2947
2948 print "Hello world"
2949
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002950Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002951
2952
2953Optional Collection of Cyclical Garbage
2954---------------------------------------
2955
2956Python is now equipped with a garbage collector that can hunt down
2957cyclical references between Python objects. It's no replacement for
2958reference counting; in fact, it depends on the reference counts being
2959correct, and decides that a set of objects belong to a cycle if all
2960their reference counts can be accounted for from their references to
2961each other. This devious scheme was first proposed by Eric Tiedemann,
2962and brought to implementation by Neil Schemenauer.
2963
2964There's a module "gc" that lets you control some parameters of the
2965garbage collection. There's also an option to the configure script
2966that lets you enable or disable the garbage collection. In 2.0b1,
2967it's on by default, so that we (hopefully) can collect decent user
2968experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00002969performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002970off by default in the final 2.0 release.
2971
2972
2973Smaller Changes
2974---------------
2975
2976A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
2977map(None, seq1, seq2, ...) when the sequences have the same length;
2978i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
2979the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002980zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002981
2982sys.version_info is a tuple (major, minor, micro, level, serial).
2983
2984Dictionaries have an odd new method, setdefault(key, default).
2985dict.setdefault(key, default) returns dict[key] if it exists; if not,
2986it sets dict[key] to default and returns that value. Thus:
2987
2988 dict.setdefault(key, []).append(item)
2989
2990does the same work as this common idiom:
2991
2992 if not dict.has_key(key):
2993 dict[key] = []
2994 dict[key].append(item)
2995
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002996There are two new variants of SyntaxError that are raised for
2997indentation-related errors: IndentationError and TabError.
2998
2999Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3000escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003001
3002The limits on the size of expressions and file in Python source code
3003have been raised from 2**16 to 2**32. Previous versions of Python
3004were limited because the maximum argument size the Python VM accepted
3005was 2**16. This limited the size of object constructor expressions,
3006e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3007limit was raised thanks to a patch by Charles Waldman that effectively
3008fixes the problem. It is now much more likely that you will be
3009limited by available memory than by an arbitrary limit in Python.
3010
3011The interpreter's maximum recursion depth can be modified by Python
3012programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3013limit is the maximum number of recursive calls that can be made by
3014Python code. The limit exists to prevent infinite recursion from
3015overflowing the C stack and causing a core dump. The default value is
30161000. The maximum safe value for a particular platform can be found
3017by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003018
3019New Modules and Packages
3020------------------------
3021
3022atexit - for registering functions to be called when Python exits.
3023
3024imputil - Greg Stein's alternative API for writing custom import
3025hooks.
3026
3027pyexpat - an interface to the Expat XML parser, contributed by Paul
3028Prescod.
3029
3030xml - a new package with XML support code organized (so far) in three
3031subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3032would fill a volume. There's a special feature whereby a
3033user-installed package named _xmlplus overrides the standard
3034xmlpackage; this is intended to give the XML SIG a hook to distribute
3035backwards-compatible updates to the standard xml package.
3036
3037webbrowser - a platform-independent API to launch a web browser.
3038
3039
Guido van Rossume905e952000-09-05 12:42:46 +00003040Changed Modules
3041---------------
3042
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003043array -- new methods for array objects: count, extend, index, pop, and
3044remove
3045
3046binascii -- new functions b2a_hex and a2b_hex that convert between
3047binary data and its hex representation
3048
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003049calendar -- Many new functions that support features including control
3050over which day of the week is the first day, returning strings instead
3051of printing them. Also new symbolic constants for days of week,
3052e.g. MONDAY, ..., SUNDAY.
3053
3054cgi -- FieldStorage objects have a getvalue method that works like a
3055dictionary's get method and returns the value attribute of the object.
3056
3057ConfigParser -- The parser object has new methods has_option,
3058remove_section, remove_option, set, and write. They allow the module
3059to be used for writing config files as well as reading them.
3060
3061ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003062optionally support the RFC 959 REST command.
3063
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003064gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003065
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003066httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3067the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003068
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003069locale -- implement getdefaultlocale for Win32 and Macintosh
3070
3071marshal -- no longer dumps core when marshaling deeply nested or
3072recursive data structures
3073
3074os -- new functions isatty, seteuid, setegid, setreuid, setregid
3075
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003076os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3077support under Unix.
3078
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003079os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003080
3081os.path -- fix semantics of os.path.commonprefix
3082
3083smtplib -- support for sending very long messages
3084
3085socket -- new function getfqdn()
3086
3087readline -- new functions to read, write and truncate history files.
3088The readline section of the library reference manual contains an
3089example.
3090
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003091select -- add interface to poll system call
3092
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003093shutil -- new copyfileobj function
3094
3095SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3096HTTP server.
3097
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003098Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003099
3100urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003101e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003102
3103whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003104
3105
3106Obsolete Modules
3107----------------
3108
3109None. However note that 1.6 made a whole slew of modules obsolete:
3110stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3111poly, zmod, strop, util, whatsound.
3112
3113
3114Changed, New, Obsolete Tools
3115----------------------------
3116
Tim Peters8b092332000-09-05 20:15:25 +00003117None.
Guido van Rossume905e952000-09-05 12:42:46 +00003118
3119
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003120C-level Changes
3121---------------
3122
3123Several cleanup jobs were carried out throughout the source code.
3124
3125All C code was converted to ANSI C; we got rid of all uses of the
3126Py_PROTO() macro, which makes the header files a lot more readable.
3127
3128Most of the portability hacks were moved to a new header file,
3129pyport.h; several other new header files were added and some old
3130header files were removed, in an attempt to create a more rational set
3131of header files. (Few of these ever need to be included explicitly;
3132they are all included by Python.h.)
3133
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003134Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003135and Win64, especially for the new Intel Itanium processor. Mick also
3136added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003137
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003138The C APIs to return an object's size have been update to consistently
3139use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3140previous versions, the abstract interfaces used PyXXX_Length and the
3141concrete interfaces used PyXXX_Size. The old names,
3142e.g. PyObject_Length, are still available for backwards compatibility
3143at the API level, but are deprecated.
3144
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003145The PyOS_CheckStack function has been implemented on Windows by
3146Fredrik Lundh. It prevents Python from failing with a stack overflow
3147on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003148
3149The GC changes resulted in creation of two new slots on object,
3150tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003151the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003152
3153The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003154C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003155
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003156PyErr_Format has been updated to automatically calculate the size of
3157the buffer needed to hold the formatted result string. This change
3158prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003159
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003160New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003161
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003162PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3163that are the same as their non-Ex counterparts except they take an
3164extra flag argument that tells them to close the file when done.
3165
3166XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003167
Tim Peters8b092332000-09-05 20:15:25 +00003168
3169Windows Changes
3170---------------
3171
3172New popen2/popen3/peopen4 in os module (see Changed Modules above).
3173
3174os.popen is much more usable on Windows 95 and 98. See Microsoft
3175Knowledge Base article Q150956. The Win9x workaround described there
3176is implemented by the new w9xpopen.exe helper in the root of your
3177Python installation. Note that Python uses this internally; it is not
3178a standalone program.
3179
3180Administrator privileges are no longer required to install Python
3181on Windows NT or Windows 2000. If you have administrator privileges,
3182Python's registry info will be written under HKEY_LOCAL_MACHINE.
3183Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003184under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003185uses of Python, but will prevent some advanced uses from working
3186(for example, running a Python script as an NT service, or possibly
3187from CGI).
3188
3189[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3190installer; instead, it installs the needed Tcl/Tk files directly in the
3191Python directory. If you already have a Tcl/Tk installation, this
3192wastes some disk space (about 4 Megs) but avoids problems with
3193conflicting Tcl/Tk installations, and makes it much easier for Python
3194to ensure that Tcl/Tk can find all its files.
3195
3196[This was new in 1.6] The Windows installer now installs by default in
3197\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3198
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003199
3200Updates to the changes between 1.5.2 and 1.6
3201--------------------------------------------
3202
3203The 1.6 NEWS file can't be changed after the release is done, so here
3204is some late-breaking news:
3205
3206New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3207and changes to getlocale() and setlocale().
3208
3209The new module is now enabled per default.
3210
3211It is not true that the encodings codecs cannot be used for normal
3212strings: the string.encode() (which is also present on 8-bit strings
3213!) allows using them for 8-bit strings too, e.g. to convert files from
3214cp1252 (Windows) to latin-1 or vice-versa.
3215
3216Japanese codecs are available from Tamito KAJIYAMA:
3217http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3218
3219
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003220======================================================================