blob: 22b08444040a62ee9941c1b47bb75d5d3aa5c551 [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
Marc-André Lemburge92e0a92002-02-09 11:28:43 +00009- The UTF-8 codec will now encode and decode Unicode surrogates
10 correctly and without raising exceptions for unpaired ones.
11
Neal Norwitz649b7592002-01-01 19:07:13 +000012- file.xreadlines() now raises a ValueError if the file is closed:
13 Previously, an xreadlines object was returned which would raise
14 a ValueError when the xreadlines.next() method was called.
15
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000016- posix.killpg has been added where available.
17
Tim Petersaf8446f2001-12-21 21:36:50 +000018Extension modules
19
Martin v. Löwis99866332002-03-01 10:27:01 +000020- array.array is now a type object. A new format character
21 'u' indicates Py_UNICODE arrays. For those, .tounicode and
22 .fromunicode methods are available. Arrays now support __iadd__
23 and __imul__.
24
Neal Norwitze790eae2002-01-01 21:14:12 +000025- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000026 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
27 is called.
28
Tim Petersaf8446f2001-12-21 21:36:50 +000029Library
30
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000031- socket module: the SSL support was broken out of the main
32 _socket module C helper and placed into a new _ssl helper
33 which now gets imported by socket.py if available and working.
34
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000035- encodings package: added aliases for all supported IANA character
36 sets
37
Guido van Rossum606fe4e2001-12-28 20:57:14 +000038- ftplib: to safeguard the user's privacy, anonymous login will use
39 "anonymous@" as default password, rather than the real user and host
40 name.
41
Fred Drake36736122002-01-10 13:50:31 +000042- webbrowser: tightened up the command passed to os.system() so that
43 arbitrary shell code can't be executed because a bogus URL was
44 passed in.
45
Tim Peters11bd9942002-02-01 00:52:29 +000046- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000047 gettext.find an optional all argument. Translations will now fallback
48 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000049
Martin v. Löwis9668b932002-01-12 11:27:42 +000050- distutils bdist commands now offer a --skip-build option.
51
Tim Petersaf8446f2001-12-21 21:36:50 +000052Tools/Demos
53
54Build
55
56C API
57
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000058- The "u#" parser marker will now pass through Unicode object as-is
59 without going through the buffer API.
60
Martin v. Löwis7198a522002-01-01 19:59:11 +000061- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
62
Tim Peters10a3bb52001-12-25 19:07:38 +000063- An old #define of ANY as void has been removed from pyport.h. This
64 hasn't been used since Python's pre-ANSI days, and the #define has
65 been marked as obsolete since then. SF bug 495548 says it created
66 conflicts with other packages, so keeping it around wasn't harmless.
67
Tim Petersaf8446f2001-12-21 21:36:50 +000068- Because Python's magic number scheme broke on January 1st, we decided
69 to stop Python development. Thanks for all the fish!
70
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000071- Some of us don't like fish, so we changed Python's magic number
72 scheme to a new one. See Python/import.c for details.
73
Tim Petersaf8446f2001-12-21 21:36:50 +000074New platforms
75
Martin v. Löwisa6e97582002-01-01 18:41:33 +000076- GNU/Hurd is now supported.
77
Tim Petersaf8446f2001-12-21 21:36:50 +000078Tests
79
80Windows
81
Tim Petersab034fa2002-02-01 11:27:43 +000082- os.waitpid() is now implemented for Windows, and can be used to block
83 until a specified process exits. This is similar to, but not exactly
84 the same as, os.waitpid() on POSIX systems. If you're waiting for
85 a specific process whose pid was obtained from one of the spawn()
86 functions, the same Python os.waitpid() code works across platforms.
87 See the docs for details.
88
Tim Peters11bd9942002-02-01 00:52:29 +000089- New tempfile.TemporaryFile implementation for Windows: this doesn't
90 need a TemproraryFileWrapper wrapper anymore, and should be immune
91 to a nasty problem: before 2.3, if you got a temp file on Windows, it
92 got wrapped in an object whose close() method first closed the
93 underlying file, then deleted the file. This usually worked fine.
94 However, the spawn family of functions on Windows create (at a low C
95 level) the same set of open files in the spawned process Q as were
96 open in the spawning process P. If a temp file f was among them, then
97 doing f.close() in P first closed P's C-level file handle on f, but Q's
98 C-level file handle on f remained open, so the attempt in P to delete f
99 blew up with a "Permission denied" error (Windows doesn't allow
100 deleting open files). This was surprising, subtle, and difficult to
101 work around.
102
103- The os module now exports all the symbolic constants usable with the
104 low-level os.open() on Windows: the new constants in 2.3 are
105 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
106 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
107 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
108 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
109 (so specify both if you want both; note that neither is useful unless
110 specified with O_CREAT too).
111
Tim Petersaf8446f2001-12-21 21:36:50 +0000112Mac
113
114
Tim Peters909c0912001-12-14 23:16:18 +0000115What's New in Python 2.2 final?
116Release date: 21-Dec-2001
117===============================
118
119Type/class unification and new-style classes
120
Barry Warsaw52acb492001-12-21 20:04:22 +0000121- pickle.py, cPickle: allow pickling instances of new-style classes
122 with a custom metaclass.
123
Tim Peters909c0912001-12-14 23:16:18 +0000124Core and builtins
125
Barry Warsaw52acb492001-12-21 20:04:22 +0000126- weakref proxy object: when comparing, unwrap both arguments if both
127 are proxies.
128
Tim Peters909c0912001-12-14 23:16:18 +0000129Extension modules
130
Barry Warsaw52acb492001-12-21 20:04:22 +0000131- binascii.b2a_base64(): fix a potential buffer overrun when encoding
132 very short strings.
133
134- cPickle: the obscure "fast" mode was suspected of causing stack
135 overflows on the Mac. Hopefully fixed this by setting the recursion
136 limit much smaller. If the limit is too low (it only affects
137 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
138 when compiling cPickle.c (or in pyconfig.h).
139
Tim Peters909c0912001-12-14 23:16:18 +0000140Library
141
Barry Warsaw52acb492001-12-21 20:04:22 +0000142- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
143 close or delete time).
144
145- rfc822.py: fixed a bug where the address '<>' was converted to None
146 instead of an empty string (also fixes the email.Utils module).
147
148- xmlrpclib.py: version 1.0.0; uses precision for doubles.
149
150- test suite: the pickle and cPickle tests were not executing any code
151 when run from the standard regresssion test.
152
Tim Peters909c0912001-12-14 23:16:18 +0000153Tools/Demos
154
155Build
156
157C API
158
159New platforms
160
161Tests
162
163Windows
164
Barry Warsaw52acb492001-12-21 20:04:22 +0000165- distutils package: fixed broken Windows installers (bdist_wininst).
166
167- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
168 instances are deleted at process exit time.
169
170- socket.py: prevent mysterious warnings when socket instances are
171 deleted at process exit time.
172
173- posixmodule.c: fix a Windows crash with stat() of a filename ending
174 in backslash.
175
Tim Peters909c0912001-12-14 23:16:18 +0000176Mac
177
Barry Warsaw52acb492001-12-21 20:04:22 +0000178- The Carbon toolbox modules have been upgraded to Universal Headers
179 3.4, and experimental CoreGraphics and CarbonEvents modules have
180 been added. All only for framework-enabled MacOSX.
181
Tim Peters909c0912001-12-14 23:16:18 +0000182
Tim Peters6272dfd2001-12-13 19:34:00 +0000183What's New in Python 2.2c1?
184Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000185===========================
186
187Type/class unification and new-style classes
188
Barry Warsaw06557452001-12-14 20:47:12 +0000189- Guido's tutorial introduction to the new type/class features has
190 been extensively updated. See
191
192 http://www.python.org/2.2/descrintro.html
193
194 That remains the primary documentation in this area.
195
Guido van Rossum33bab012001-12-05 22:45:48 +0000196- Fixed a leak: instance variables declared with __slots__ were never
197 deleted!
198
Guido van Rossum4b800852001-12-03 00:54:52 +0000199- The "delete attribute" method of descriptor objects is called
200 __delete__, not __del__. In previous releases, it was mistakenly
201 called __del__, which created an unfortunate overloading condition
202 with finalizers. (The "get attribute" and "set attribute" methods
203 are still called __get__ and __set__, respectively.)
204
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000205- Some subtle issues with the super built-in were fixed:
206
207 (a) When super itself is subclassed, its __get__ method would still
208 return an instance of the base class (i.e., of super).
209
210 (b) super(C, C()).__class__ would return C rather than super. This
211 is confusing. To fix this, I decided to change the semantics of
212 super so that it only applies to code attributes, not to data
213 attributes. After all, overriding data attributes is not
214 supported anyway.
215
216 (c) The __get__ method didn't check whether the argument was an
217 instance of the type used in creation of the super instance.
218
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000219- Previously, hash() of an instance of a subclass of a mutable type
220 (list or dictionary) would return some value, rather than raising
221 TypeError. This has been fixed. Also, directly calling
222 dict.__hash__ and list.__hash__ now raises the same TypeError
223 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000224
Guido van Rossumd331cb52001-12-05 19:46:42 +0000225- New-style objects now support deleting their __dict__. This is for
226 all intents and purposes equivalent to assigning a brand new empty
227 dictionary, but saves space if the object is not used further.
228
Tim Petersb3c9af12001-11-17 00:21:57 +0000229Core and builtins
230
Tim Peters3caca232001-12-06 06:23:26 +0000231- -Qnew now works as documented in PEP 238: when -Qnew is passed on
232 the command line, all occurrences of "/" use true division instead
233 of classic division. See the PEP for details. Note that "all"
234 means all instances in library and 3rd-party modules, as well as in
235 your own code. As the PEP says, -Qnew is intended for use only in
236 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000237 Note that test_coercion.py in the standard Python test suite fails
238 under -Qnew; this is expected, and won't be repaired until true
239 division becomes the default (in the meantime, test_coercion is
240 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000241
Fred Drake6c01e252001-12-14 17:08:12 +0000242- complex() now only allows the first argument to be a string
243 argument, and raises TypeError if either the second arg is a string
244 or if the second arg is specified when the first is a string.
245
Tim Petersb3c9af12001-11-17 00:21:57 +0000246Extension modules
247
Martin v. Löwis560da622001-11-24 09:24:51 +0000248- gc.get_referents was renamed to gc.get_referrers.
249
Tim Petersb3c9af12001-11-17 00:21:57 +0000250Library
251
Tim Peters25059d32001-12-07 20:35:43 +0000252- Functions in the os.spawn() family now release the global interpreter
253 lock around calling the platform spawn. They should always have done
254 this, but did not before 2.2c1. Multithreaded programs calling
255 an os.spawn function with P_WAIT will no longer block all Python threads
256 until the spawned program completes. It's possible that some programs
257 relies on blocking, although more likely by accident than by design.
258
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000259- webbrowser defaults to netscape.exe on OS/2 now.
260
Martin v. Löwis652e1912001-11-25 14:50:56 +0000261- Tix.ResizeHandle exposes detach_widget, hide, and show.
262
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000263- The charset alias windows_1252 has been added.
264
Barry Warsaw06557452001-12-14 20:47:12 +0000265- types.StringTypes is a tuple containing the defined string types;
266 usually this will be (str, unicode), but if Python was compiled
267 without Unicode support it will be just (str,).
268
269- The pulldom and minidom modules were synchronized to PyXML.
270
Tim Petersb3c9af12001-11-17 00:21:57 +0000271Tools/Demos
272
Barry Warsaw06557452001-12-14 20:47:12 +0000273- A new script called Tools/scripts/google.py was added, which fires
274 off a search on Google.
275
Tim Petersb3c9af12001-11-17 00:21:57 +0000276Build
277
Barry Warsaw06557452001-12-14 20:47:12 +0000278- Note that release builds of Python should arrange to define the
279 preprocessor symbol NDEBUG on the command line (or equivalent).
280 In the 2.2 pre-release series we tried to define this by magic in
281 Python.h instead, but it proved to cause problems for extension
282 authors. The Unix, Windows and Mac builds now all define NDEBUG in
283 release builds via cmdline (or equivalent) instead. Ports to
284 other platforms should do likewise.
285
Jack Jansen1999ef42001-12-06 21:47:20 +0000286- It is no longer necessary to use --with-suffix when building on a
287 case-insensitive file system (such as Mac OS X HFS+). In the build
288 directory an extension is used, but not in the installed python.
289
Tim Petersb3c9af12001-11-17 00:21:57 +0000290C API
291
Tim Petersf582b822001-12-11 18:51:08 +0000292- New function PyDict_MergeFromSeq2() exposes the builtin dict
293 constructor's logic for updating a dictionary from an iterable object
294 producing key-value pairs.
295
Tim Peterscffed4b2001-11-29 03:26:37 +0000296- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000297 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000298 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
299 dump core in some bad cases. This has been repaired. As a result,
300 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
301 previously went unchallenged.
302
Tim Petersb3c9af12001-11-17 00:21:57 +0000303New platforms
304
305Tests
306
307Windows
308
309Mac
310
Jack Jansenffa260f2001-12-06 21:14:00 +0000311- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
312 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000313
Barry Warsaw06557452001-12-14 20:47:12 +0000314- Changed logic for finding python home in Mac OS X framework Pythons.
315 Now sys.executable points to the executable again, in stead of to
316 the shared library. The latter is used only for locating the python
317 home.
318
319
Tim Peters84362bc2001-10-19 17:55:30 +0000320What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000321Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000322===========================
323
324Type/class unification and new-style classes
325
Guido van Rossum3d27df02001-11-15 20:27:54 +0000326- Multiple inheritance mixing new-style and classic classes in the
327 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000328
329 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000330 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000331
332 The MRO (method resolution order) for each base class is respected
333 according to its kind, but the MRO for the derived class is computed
334 using new-style MRO rules if any base clase is a new-style class.
335 This needs to be documented.
336
Tim Petersa427a2b2001-10-29 22:25:45 +0000337- The new builtin dictionary() constructor, and dictionary type, have
338 been renamed to dict. This reflects a decade of common usage.
339
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000340- dict() now accepts an iterable object producing 2-sequences. For
341 example, dict(d.items()) == d for any dictionary d. The argument,
342 and the elements of the argument, can be any iterable objects.
343
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000344- New-style classes can now have a __del__ method, which is called
345 when the instance is deleted (just like for classic classes).
346
Guido van Rossum12d955c2001-10-26 14:56:06 +0000347- Assignment to object.__dict__ is now possible, for objects that are
348 instances of new-style classes that have a __dict__ (unless the base
349 class forbids it).
350
Guido van Rossumc8e56452001-10-22 00:43:43 +0000351- Methods of built-in types now properly check for keyword arguments
352 (formerly these were silently ignored). The only built-in methods
353 that take keyword arguments are __call__, __init__ and __new__.
354
Guido van Rossum86443212001-10-27 22:28:54 +0000355- The socket function has been converted to a type; see below.
356
Tim Peters84362bc2001-10-19 17:55:30 +0000357Core and builtins
358
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000359- Assignment to __debug__ raises SyntaxError at compile-time. This
360 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000361 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000362
Guido van Rossum12d955c2001-10-26 14:56:06 +0000363- Clarified the error messages for unsupported operands to an operator
364 (like 1 + '').
365
Tim Peters84362bc2001-10-19 17:55:30 +0000366Extension modules
367
Tim Peters5ebfd362001-11-13 23:11:19 +0000368- mmap has a new keyword argument, "access", allowing a uniform way for
369 both Windows and Unix users to create read-only, write-through and
370 copy-on-write memory mappings. This was previously possible only on
371 Unix. A new keyword argument was required to support this in a
372 uniform way because the mmap() signuatures had diverged across
373 platforms. Thanks to Jay T Miller for repairing this!
374
Tim Peters169ded02001-11-03 19:57:21 +0000375- By default, the gc.garbage list now contains only those instances in
376 unreachable cycles that have __del__ methods; in 2.1 it contained all
377 instances in unreachable cycles. "Instances" here has been generalized
378 to include instances of both new-style and old-style classes.
379
Guido van Rossum12d955c2001-10-26 14:56:06 +0000380- The socket module defines a new method for socket objects,
381 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000382 send() until all data has been sent. Also, the socket function has
383 been converted to a subclassable type, like list and tuple (etc.)
384 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000385
386- Various bugfixes to the curses module. There is now a test suite
387 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000388
Guido van Rossum692adf12001-10-30 03:03:03 +0000389- binascii.b2a_base64 no longer places an arbitrary restriction of 57
390 bytes on its input.
391
Tim Peters84362bc2001-10-19 17:55:30 +0000392Library
393
Tim Peters5ebfd362001-11-13 23:11:19 +0000394- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000395 convenience function.
396
Tim Peters75335872001-11-03 19:35:43 +0000397- Symbolic group names in regular expressions must be unique. For
398 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
399 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000400 Python 2.2 detects this error at regexp compilation time;
401 previously, the error went undetected, and results were
402 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
403 pattern.subn() methods have been rewritten in C. Also, an
404 experimental function/method finditer() has been added, which works
405 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000406
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000407- Tix exposes more commands through the classes DirSelectBox,
408 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
409 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
410 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
411
Tim Peters98791af2001-10-23 01:59:54 +0000412- Traceback objects are now scanned by cyclic garbage collection, so
413 cycles created by casual use of sys.exc_info() no longer cause
414 permanent memory leaks (provided garbage collection is enabled).
415
Guido van Rossum49192142001-10-24 20:51:44 +0000416- os.extsep -- a new variable needed by the RISCOS support. It is the
417 separator used by extensions, and is '.' on all platforms except
418 RISCOS, where it is '/'. There is no need to use this variable
419 unless you have a masochistic desire to port your code to RISCOS.
420
Barry Warsaw012852b2001-11-16 16:17:27 +0000421- mimetypes.py has optional support for non-standard, but commonly
422 found types. guess_type() and guess_extension() now accept an
423 optional `strict' flag, defaulting to true, which controls whether
424 recognize non-standard types or not. A few non-standard types we
425 know about have been added. Also, when run as a script, there are
426 new -l and -e options.
427
428- statcache is now deprecated.
429
430- email.Utils.formatdate() now produces the preferred RFC 2822 style
431 dates with numeric timezones (it used to produce obsolete dates
432 hard coded to "GMT" timezone). An optional `localtime' flag is
433 added to produce dates in the local timezone, with daylight savings
434 time properly taken into account.
435
436- In pickle and cPickle, instead of masking errors in load() by
437 transforming them into SystemError, we let the original exception
438 propagate out. Also, implement support for __safe_for_unpickling__
439 in pickle, as it already was supported in cPickle.
440
Tim Peters84362bc2001-10-19 17:55:30 +0000441Tools/Demos
442
443Build
444
Barry Warsaw012852b2001-11-16 16:17:27 +0000445- The dbm module is built using libdb1 if available. The bsddb module
446 is built with libdb3 if available.
447
448- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
449
Tim Peters84362bc2001-10-19 17:55:30 +0000450C API
451
Tim Peters1fc240e2001-10-26 05:06:50 +0000452- New function PySequence_Fast_GET_SIZE() returns the size of a non-
453 NULL result from PySequence_Fast(), more quickly than calling
454 PySequence_Size().
455
Barry Warsaw012852b2001-11-16 16:17:27 +0000456- New argument unpacking function PyArg_UnpackTuple() added.
457
458- New functions PyObject_CallFunctionObjArgs() and
459 PyObject_CallMethodObjArgs() have been added to make it more
460 convenient and efficient to call functions and methods from C.
461
462- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
463 possible that this will propagate errors it didn't before.
464
465- New function PyObject_CheckReadBuffer(), which returns true if its
466 argument supports the single-segment readable buffer interface.
467
Tim Peters84362bc2001-10-19 17:55:30 +0000468New platforms
469
Guido van Rossum86443212001-10-27 22:28:54 +0000470- We've finally confirmed that this release builds on HP-UX 11.00,
471 *with* threads, and passes the test suite.
472
Tim Peters7a33d8b2001-11-05 02:51:07 +0000473- Thanks to a series of patches from Michael Muller, Python may build
474 again under OS/2 Visual Age C++.
475
Guido van Rossum49192142001-10-24 20:51:44 +0000476- Updated RISCOS port by Dietmar Schwertberger.
477
Tim Peters84362bc2001-10-19 17:55:30 +0000478Tests
479
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000480- Added a test script for the curses module. It isn't run automatically;
481 regrtest.py must be run with '-u curses' to enable it.
482
Tim Peters84362bc2001-10-19 17:55:30 +0000483Windows
484
Barry Warsaw012852b2001-11-16 16:17:27 +0000485Mac
486
487- PythonScript has been moved to unsupported and is slated to be
488 removed completely in the next release.
489
490- It should now be possible to build applets that work on both OS9 and
491 OSX.
492
493- The core is now linked with CoreServices not Carbon; as a side
494 result, default 8bit encoding on OSX is now ASCII.
495
496- Python should now build on OSX 10.1.1
497
Tim Peters84362bc2001-10-19 17:55:30 +0000498
Tim Petersabf925f2001-09-28 21:53:42 +0000499What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000500Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000501===========================
502
503Type/class unification and new-style classes
504
Guido van Rossum687ae002001-10-15 22:03:32 +0000505- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000506 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000507 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000508 remains: the __dict__ of a new-style class is a read-only proxy; you
509 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000510 __defined__ attribute of new-style types no longer exists, for lack
511 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000512 future a __cache__ may be resurrected with a similar function, if I
513 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000514
Tim Peters1c9ca872001-10-04 06:43:12 +0000515- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
516 always returned None, even when there was a class docstring).
517
518- doctest now finds and runs docstrings attached to new-style classes,
519 class methods, static methods, and properties.
520
Guido van Rossum9074ef62001-10-16 21:34:49 +0000521Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000522
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000523- A very subtle syntactical pitfall in list comprehensions was fixed.
524 For example: [a+b for a in 'abc', for b in 'def']. The comma in
525 this example is a mistake. Previously, this would silently let 'a'
526 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
527 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
528 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
529 Note that [a for a in <singleton>] is a convoluted way to say
530 [<singleton>] anyway, so it's not like any expressiveness is lost.
531
Guido van Rossum9074ef62001-10-16 21:34:49 +0000532- getattr(obj, name, default) now only catches AttributeError, as
533 documented, rather than returning the default value for all
534 exceptions (which could mask bugs in a __getattr__ hook, for
535 example).
536
Fred Drakecb7a6b52001-10-22 18:41:51 +0000537- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000538 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000539 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000540 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000541
Guido van Rossum1c486092001-10-19 02:05:35 +0000542- unicode(obj) now behaves more like str(obj), accepting arbitrary
543 objects, and calling a __unicode__ method if it exists.
544 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000545 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000546
Barry Warsawf6fb1712001-10-19 05:35:40 +0000547- isinstance() now allows any object as the first argument and a
548 class, a type or something with a __bases__ tuple attribute for the
549 second argument. The second argument may also be a tuple of a
550 class, type, or something with __bases__, in which case isinstance()
551 will return true if the first argument is an instance of any of the
552 things contained in the second argument tuple. E.g.
553
554 isinstance(x, (A, B))
555
556 returns true if x is an instance of A or B.
557
Guido van Rossum9074ef62001-10-16 21:34:49 +0000558Extension modules
559
560- thread.start_new_thread() now returns the thread ID (previously None).
561
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000562- binascii has now two quopri support functions, a2b_qp and b2a_qp.
563
Guido van Rossumc524d952001-10-19 01:31:59 +0000564- readline now supports setting the startup_hook and the
565 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000566
Guido van Rossumc524d952001-10-19 01:31:59 +0000567- os and posix supports chroot(), setgroups() and unsetenv() where
568 available. The stat(), fstat(), statvfs() and fstatvfs() functions
569 now return "pseudo-sequences" -- the various fields can now be
570 accessed as attributes (e.g. os.stat("/").st_mtime) but for
571 backwards compatibility they also behave as a fixed-length sequence.
572 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000573 attributes.
574
575- time: localtime(), gmtime() and strptime() now return a
576 pseudo-sequence similar to the os.stat() return value, with
577 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000578
Guido van Rossum9074ef62001-10-16 21:34:49 +0000579- Decompression objects in the zlib module now accept an optional
580 second parameter to decompress() that specifies the maximum amount
581 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000582
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000583- optional SSL support in the socket module now exports OpenSSL
584 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
585 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000586 automatically seed its PRNG. Also, the keyfile and certfile
587 arguments to socket.ssl() are now optional.
588
589- posixmodule (and by extension, the os module on POSIX platforms) now
590 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000591
Guido van Rossum9074ef62001-10-16 21:34:49 +0000592Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000593
Tim Peters7402f792001-10-02 03:53:41 +0000594- doctest now excludes functions and classes not defined by the module
595 being tested, thanks to Tim Hochberg.
596
Fred Drakecb7a6b52001-10-22 18:41:51 +0000597- HotShot, a new profiler implemented using a C-based callback, has
598 been added. This substantially reduces the overhead of profiling,
599 but it is still quite preliminary. Support modules and
600 documentation will be added in upcoming releases (before 2.2 final).
601
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000602- profile now produces correct output in situations where an exception
603 raised in Python is cleared by C code (e.g. hasattr()). This used
604 to cause wrong output, including spurious claims of recursive
605 functions and attribution of time spent to the wrong function.
606
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000607 The code and documentation for the derived OldProfile and HotProfile
608 profiling classes was removed. The code hasn't worked for years (if
609 you tried to use them, they raised exceptions). OldProfile
610 intended to reproduce the behavior of the profiler Python used more
611 than 7 years ago, and isn't interesting anymore. HotProfile intended
612 to provide a faster profiler (but producing less information), and
613 that's a worthy goal we intend to meet via a different approach (but
614 without losing information).
615
Tim Peterscce092d2001-10-09 05:31:56 +0000616- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000617 a much better system-specific calibration constant. The constant can
618 now be specified in an instance constructor, or as a Profile class or
619 instance variable, instead of by editing profile.py's source code.
620 Calibration must still be done manually (see the docs for the profile
621 module).
622
623 Note that Profile.calibrate() must be overriden by subclasses.
624 Improving the accuracy required exploiting detailed knowledge of
625 profiler internals; the earlier method abstracted away the details
626 and measured a simplified model instead, but consequently computed
627 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000628
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000629- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000630 which indicates whether output is intended for the header 'Q'
631 encoding.
632
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000633- The SocketServer.ThreadingMixIn class now closes the request after
634 finish_request() returns. (Not when it errors out though.)
635
Barry Warsawf6fb1712001-10-19 05:35:40 +0000636- The nntplib module's NNTP.body() method has grown a `file' argument
637 to allow saving the message body to a file.
638
639- The email package has added a class email.Parser.HeaderParser which
640 only parses headers and does not recurse into the message's body.
641 Also, the module/class MIMEAudio has been added for representing
642 audio data (contributed by Anthony Baxter).
643
644- ftplib should be able to handle files > 2GB.
645
646- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
647 ON, and OFF.
648
Fred Drakecb7a6b52001-10-22 18:41:51 +0000649- xml.dom.minidom NodeList objects now support the length attribute
650 and item() method as required by the DOM specifications.
651
Guido van Rossumed554f62001-10-02 23:15:37 +0000652Tools/Demos
653
654- Demo/dns was removed. It no longer serves any purpose; a package
655 derived from it is now maintained by Anthony Baxter, see
656 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000657
Barry Warsawf6fb1712001-10-19 05:35:40 +0000658- The freeze tool has been made more robust, and two new options have
659 been added: -X and -E.
660
Tim Petersabf925f2001-09-28 21:53:42 +0000661Build
662
Barry Warsawf6fb1712001-10-19 05:35:40 +0000663- configure will use CXX in LINKCC if CXX is used to build main() and
664 the system requires to link a C++ main using the C++ compiler.
665
Tim Petersabf925f2001-09-28 21:53:42 +0000666C API
667
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000668- The documentation for the tp_compare slot is updated to require that
669 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
670 not correct. This is not yet enforced but will be enforced in
671 Python 2.3; even later, we may use -2 to indicate errors and +2 for
672 "NotImplemented". Right now, -1 should be used for an error return.
673
Tim Petersd38b1c72001-09-30 05:09:37 +0000674- PyLong_AsLongLong() now accepts int (as well as long) arguments.
675 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
676 as long) arguments.
677
Guido van Rossum3c288632001-10-16 21:13:49 +0000678- PyThread_start_new_thread() now returns a long int giving the thread
679 ID, if one can be calculated; it returns -1 for error, 0 if no
680 thread ID is calculated (this is an incompatible change, but only
681 the thread module used this API). This code has only really been
682 tested on Linux and Windows; other platforms please beware (and
683 report any bugs or strange behavior).
684
Guido van Rossum1c486092001-10-19 02:05:35 +0000685- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
686 input.
687
Tim Petersabf925f2001-09-28 21:53:42 +0000688New platforms
689
690Tests
691
692Windows
693
Tim Peters04cf1d32001-10-09 22:39:40 +0000694- Installer: If you install IDLE, and don't disable file-extension
695 registration, a new "Edit with IDLE" context (right-click) menu entry
696 is created for .py and .pyw files.
697
Tim Peters1ce3cf72001-10-01 17:58:40 +0000698- The signal module now supports SIGBREAK on Windows, thanks to Steven
699 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
700 action remains to call Win32 ExitProcess(). This can be changed via
701 signal.signal(). For example:
702
703 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
704 # (SIGINT) behavior.
705 import signal
706 signal.signal(signal.SIGBREAK,
707 signal.default_int_handler)
708
709 try:
710 while 1:
711 pass
712 except KeyboardInterrupt:
713 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
714 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
715 # program without the possibility for any Python-level cleanup).
716 print "Clean exit"
717
Tim Petersabf925f2001-09-28 21:53:42 +0000718
Tim Petersb07352e2001-09-08 01:25:47 +0000719What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000720Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000721===========================
722
Guido van Rossum808eea72001-09-25 04:15:41 +0000723Type/class unification and new-style classes
724
725- pydoc and inspect are now aware of new-style classes;
726 e.g. help(list) at the interactive prompt now shows proper
727 documentation for all operations on list objects.
728
729- Applications using Jim Fulton's ExtensionClass module can now safely
730 be used with Python 2.2. In particular, Zope 2.4.1 now works with
731 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
732 examples also work again. It is hoped that Gtk and Boost also work
733 with 2.2a4 and beyond. (If you can confirm this, please write
734 webmaster@python.org; if there are still problems, please open a bug
735 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000736
Tim Peters66c1a522001-09-24 21:17:50 +0000737- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
738 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
739 in the constructed property object. fget, fset and fdel weren't
740 discoverable from Python in 2.2a3. __doc__ is new, and allows to
741 associate a docstring with a property.
742
Guido van Rossum808eea72001-09-25 04:15:41 +0000743- Comparison overloading is now more completely implemented. For
744 example, a str subclass instance can properly be compared to a str
745 instance, and it can properly overload comparison. Ditto for most
746 other built-in object types.
747
748- The repr() of new-style classes has changed; instead of <type
749 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
750 *except* for built-in types, which are still rendered as <type
751 'Foo'> (to avoid upsetting existing code that might parse or
752 otherwise rely on repr() of certain type objects).
753
754- The repr() of new-style objects is now always <Foo object at XXX>;
755 previously, it was sometimes <Foo instance at XXX>.
756
757- For new-style classes, what was previously called __getattr__ is now
758 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000759 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000760 one in classic classes is defined which is called only if regular
761 attribute access raises AttributeError; to catch *all* attribute
762 access, you can use __getattribute__ (for new-style classes). If
763 both are defined, __getattribute__ is called first, and if it raises
764 AttributeError, __getattr__ is called.
765
766- The __class__ attribute of new-style objects can be assigned to.
767 The new class must have the same C-level object layout as the old
768 class.
769
770- The builtin file type can be subclassed now. In the usual pattern,
771 "file" is the name of the builtin type, and file() is a new builtin
772 constructor, with the same signature as the builtin open() function.
773 file() is now the preferred way to open a file.
774
775- Previously, __new__ would only see sequential arguments passed to
776 the type in a constructor call; __init__ would see both sequential
777 and keyword arguments. This made no sense whatsoever any more, so
778 now both __new__ and __init__ see all arguments.
779
780- Previously, hash() applied to an instance of a subclass of str or
781 unicode always returned 0. This has been repaired.
782
783- Previously, an operation on an instance of a subclass of an
784 immutable type (int, long, float, complex, tuple, str, unicode),
785 where the subtype didn't override the operation (and so the
786 operation was handled by the builtin type), could return that
787 instance instead a value of the base type. For example, if s was of
788 a str sublass type, s[:] returned s as-is. Now it returns a str
789 with the same value as s.
790
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000791- Provisional support for pickling new-style objects has been added.
792
Guido van Rossum808eea72001-09-25 04:15:41 +0000793Core
794
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000795- file.writelines() now accepts any iterable object producing strings.
796
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000797- PyUnicode_FromEncodedObject() now works very much like
798 PyObject_Str(obj) in that it tries to use __str__/tp_str
799 on the object if the object is not a string or buffer. This
800 makes unicode() behave like str() when applied to non-string/buffer
801 objects.
802
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000803- PyFile_WriteObject now passes Unicode objects to the file's write
804 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000805 of a print statement must support Unicode objects, i.e. they must
806 at least convert them into ASCII strings.
807
Guido van Rossum624c8af2001-09-18 15:21:04 +0000808- Thread scheduling on Solaris should be improved; it is no longer
809 necessary to insert a small sleep at the start of a thread in order
810 to let other runnable threads be scheduled.
811
Tim Petersb07352e2001-09-08 01:25:47 +0000812Library
813
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000814- StringIO.StringIO instances and cStringIO.StringIO instances support
815 read character buffer compatible objects for their .write() methods.
816 These objects are converted to strings and then handled as such
817 by the instances.
818
Barry Warsaw2f600732001-09-24 04:28:10 +0000819- The "email" package has been added. This is basically a port of the
820 mimelib package <http://sf.net/projects/mimelib> with API changes
821 and some implementations updated to use iterators and generators.
822
Tim Peters8a9c2842001-09-22 21:30:22 +0000823- difflib.ndiff() and difflib.Differ.compare() are generators now. This
824 restores the ability of Tools/scripts/ndiff.py to start producing output
825 before the entire comparison is complete.
826
Barry Warsaw58b072d2001-09-22 04:44:21 +0000827- StringIO.StringIO instances and cStringIO.StringIO instances support
828 iteration just like file objects (i.e. their .readline() method is
829 called for each iteration until it returns an empty string).
830
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000831- The codecs module has grown four new helper APIs to access
832 builtin codecs: getencoder(), getdecoder(), getreader(),
833 getwriter().
834
Guido van Rossum624c8af2001-09-18 15:21:04 +0000835- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
836 simplifies writing XML RPC servers.
837
Barry Warsaw647d5e82001-09-28 17:01:02 +0000838- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000839 after interpretation of symbolic links. On non-Unix systems, this
840 is an alias for os.path.abspath().
841
Tim Peters16a77ad2001-09-08 04:00:12 +0000842- operator.indexOf() (PySequence_Index() in the C API) now works with any
843 iterable object.
844
Guido van Rossum624c8af2001-09-18 15:21:04 +0000845- smtplib now supports various authentication and security features of
846 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000847
Guido van Rossum624c8af2001-09-18 15:21:04 +0000848- hmac: a new module implementing keyed hashing for message
849 authentication.
850
851- mimetypes now recognizes more extensions and file types. At the
852 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000853
Guido van Rossum624c8af2001-09-18 15:21:04 +0000854- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000855 Python 2.2 bytecode generation. It has also been promoted from a
856 Tool to a standard library package. (Tools/compiler still exists as
857 a sample driver.)
858
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000859Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000860
Tim Petersb07352e2001-09-08 01:25:47 +0000861Build
862
Guido van Rossum624c8af2001-09-18 15:21:04 +0000863- Large file support (LFS) is now automatic when the platform supports
864 it; no more manual configuration tweaks are needed. On Linux, at
865 least, it's possible to have a system whose C library supports large
866 files but whose kernel doesn't; in this case, large file support is
867 still enabled but doesn't do you any good unless you upgrade your
868 kernel or share your Python executable with another system whose
869 kernel has large file support.
870
871- The configure script now supplies plausible defaults in a
872 cross-compilation environment. This doesn't mean that the supplied
873 values are always correct, or that cross-compilation now works
874 flawlessly -- but it's a first step (and it shuts up most of
875 autoconf's warnings about AC_TRY_RUN).
876
877- The Unix build is now a bit less chatty, courtesy of the parser
878 generator. The build is completely silent (except for errors) when
879 using "make -s", thanks to a -q option to setup.py.
880
Tim Petersb07352e2001-09-08 01:25:47 +0000881C API
882
Guido van Rossum624c8af2001-09-18 15:21:04 +0000883- The "structmember" API now supports some new flag bits to deny read
884 and/or write access to attributes in restricted execution mode.
885
Tim Petersb07352e2001-09-08 01:25:47 +0000886New platforms
887
Guido van Rossum624c8af2001-09-18 15:21:04 +0000888- Compaq's iPAQ handheld, running the "familiar" Linux distribution
889 (http://familiar.handhelds.org).
890
Tim Petersb07352e2001-09-08 01:25:47 +0000891Tests
892
Tim Peters8a9c2842001-09-22 21:30:22 +0000893- The "classic" standard tests, which work by comparing stdout to
894 an expected-output file under Lib/test/output/, no longer stop at
895 the first mismatch. Instead the test is run to completion, and a
896 variant of ndiff-style comparison is used to report all differences.
897 This is much easier to understand than the previous style of reporting.
898
899- The unittest-based standard tests now use regrtest's test_main()
900 convention, instead of running as a side-effect of merely being
901 imported. This allows these tests to be run in more natural and
902 flexible ways as unittests, outside the regrtest framework.
903
904- regrtest.py is much better integrated with unittest and doctest now,
905 especially in regard to reporting errors.
906
Tim Petersb07352e2001-09-08 01:25:47 +0000907Windows
908
Guido van Rossum624c8af2001-09-18 15:21:04 +0000909- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000910 that support it (NTFS under Windows 2000). See "What's New in
911 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000912
Tim Petersb07352e2001-09-08 01:25:47 +0000913
Tim Petersedc99312001-08-22 21:36:50 +0000914What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000915Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000916===========================
917
918Core
919
Tim Peters9fffa3e2001-09-04 05:14:19 +0000920- Conversion of long to float now raises OverflowError if the long is too
921 big to represent as a C double.
922
Tim Peters32f453e2001-09-03 08:35:41 +0000923- The 3-argument builtin pow() no longer allows a third non-None argument
924 if either of the first two arguments is a float, or if both are of
925 integer types and the second argument is negative (in which latter case
926 the arguments are converted to float, so this is really the same
927 restriction).
928
Tim Peters5d2b77c2001-09-03 05:47:38 +0000929- The builtin dir() now returns more information, and sometimes much
930 more, generally naming all attributes of an object, and all attributes
931 reachable from the object via its class, and from its class's base
932 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
933 an empty list. In 2.2a3,
934
935 >>> dir([])
936 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
937 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
938 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
939 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
940 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
941 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
942 'reverse', 'sort']
943
944 dir(module) continues to return only the module's attributes, though.
945
Tim Petersbdee63f2001-09-02 03:40:59 +0000946- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000947 than raising OverflowError. This is a partial implementation of PEP
948 237. You can use -Wdefault::OverflowWarning to enable a warning for
949 this situation, and -Werror::OverflowWarning to revert to the old
950 OverflowError exception.
951
Guido van Rossum61c345f2001-09-04 03:26:15 +0000952- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000953 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000954 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
955 -Qold, meaning the / operator has its classic meaning and no
956 warnings are issued. Using -Qwarn issues a run-time warning about
957 all uses of classic division for int and long arguments; -Qwarnall
958 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000959 (for use with fixdiv.py).
960 [Note: the remainder of this paragraph (preserved below) became
961 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
962 <obsolete>
963 Using -Qnew is questionable; it turns on new division by default, but
964 only in the __main__ module. You can usefully combine -Qwarn or
965 -Qwarnall and -Qnew: this gives the __main__ module new division, and
966 warns about classic division everywhere else.
967 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000968
Tim Petersbdee63f2001-09-02 03:40:59 +0000969- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000970 long, float, str, unicode, and tuple. (The types complex, list and
971 dictionary can also be subclassed; this was introduced earlier.)
972 Note that restrictions apply when subclassing immutable built-in
973 types: you can only affect the value of the instance by overloading
974 __new__. You can add mutable attributes, and the subclass instances
975 will have a __dict__ attribute, but you cannot change the "value"
976 (as implemented by the base class) of an immutable subclass instance
977 once it is created.
978
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000979- The dictionary constructor now takes an optional argument, a
980 mapping-like object, and initializes the dictionary from its
981 (key, value) pairs.
982
Tim Petersbdee63f2001-09-02 03:40:59 +0000983- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000984 "cooperative super calls" in a multiple inheritance setting. For an
985 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
986
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000987- A new built-in type, property, has been added. This enables the
988 creation of "properties". These are attributes implemented by
989 getter and setter functions (or only one of these for read-only or
990 write-only attributes), without the need to override __getattr__.
991 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000992
Tim Petersbdee63f2001-09-02 03:40:59 +0000993- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000994 liberalized, to allow leading zeroes. Examples of literals now
995 legal that were SyntaxErrors before:
996
997 00.0 0e3 0100j 07.5 00000000000000000008.
998
Tim Petersbdee63f2001-09-02 03:40:59 +0000999- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001000 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1001
Tim Petersedc99312001-08-22 21:36:50 +00001002Library
1003
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001004- telnetlib includes symbolic names for the options, and support for
1005 setting an option negotiation callback.
1006
Tim Petersa40c7932001-09-05 22:36:56 +00001007- The new C standard no longer requires that math libraries set errno to
1008 ERANGE on overflow. For platform libraries that exploit this new
1009 freedom, Python's overflow-checking was wholly broken. A new overflow-
1010 checking scheme attempts to repair that, but may not be reliable on all
1011 platforms (C doesn't seem to provide anything both useful and portable
1012 in this area anymore).
1013
Martin v. Löwis44f86962001-09-05 13:44:54 +00001014- Asynchronous timeout actions are available through the new class
1015 threading.Timer.
1016
Tim Peters78526162001-09-05 00:53:45 +00001017- math.log and math.log10 now return sensible results for even huge
1018 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1019
Tim Petersbdee63f2001-09-02 03:40:59 +00001020- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001021 currently held. See the docs for the imp module.
1022
Tim Petersbdee63f2001-09-02 03:40:59 +00001023- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001024 dumps containing ints written on platforms where Python ints are 8 bytes.
1025 When read on a box where Python ints are 4 bytes, such values are
1026 converted to Python longs.
1027
Tim Petersbdee63f2001-09-02 03:40:59 +00001028- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001029 code objects is no longer allowed. This plugs a security hole.
1030
Steve Purcell6091cd62001-09-06 16:05:17 +00001031- unittest.TestResult instances no longer store references to tracebacks
1032 generated by test failures. This prevents unexpected dangling references
1033 to objects that should be garbage collected between tests.
1034
Tim Petersedc99312001-08-22 21:36:50 +00001035Tools
1036
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001037- Tools/scripts/fixdiv.py has been added which can be used to fix
1038 division operators as per PEP 238.
1039
Tim Petersedc99312001-08-22 21:36:50 +00001040Build
1041
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001042- If you are an adventurous person using Mac OS X you may want to look at
1043 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1044 application, which can be used for experimenting with Carbon or Cocoa.
1045 Discussion of this on pythonmac-sig, please.
1046
Tim Peters7eea37e2001-09-04 22:08:56 +00001047C API
1048
1049- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001050
Tim Peters9fffa3e2001-09-04 05:14:19 +00001051- Note that PyLong_AsDouble can fail! This has always been true, but no
1052 callers checked for it. It's more likely to fail now, because overflow
1053 errors are properly detected now. The proper way to check:
1054
1055 double x = PyLong_AsDouble(some_long_object);
1056 if (x == -1.0 && PyErr_Occurred()) {
1057 /* The conversion failed. */
1058 }
1059
Tim Petersbdee63f2001-09-02 03:40:59 +00001060- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001061 compile but will not participate in GC. To upgrade an extension
1062 module:
1063
1064 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001065
Neil Schemenauer4042c692001-08-30 15:38:01 +00001066 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1067 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001068
Neil Schemenauer4042c692001-08-30 15:38:01 +00001069 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1070 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001071
Neil Schemenauer4042c692001-08-30 15:38:01 +00001072 - remove PyGC_HEAD_SIZE from object size calculations
1073
1074 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1075
Tim Petersbdee63f2001-09-02 03:40:59 +00001076- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001077 These can be used safely to construct string objects from a
1078 sprintf-style format string (similar to the format string supported
1079 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001080
Tim Petersedc99312001-08-22 21:36:50 +00001081New platforms
1082
Tim Petersb7da0902001-09-02 23:01:43 +00001083- Stephen Hansen contributed patches sufficient to get a clean compile
1084 under Borland C (Windows), but he reports problems running it and ran
1085 out of time to complete the port. Volunteers? Expect a MemoryError
1086 when importing the types module; this is probably shallow, and
1087 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001088
Tim Petersedc99312001-08-22 21:36:50 +00001089Tests
1090
1091Windows
1092
Tim Peters6e13a562001-09-06 00:32:15 +00001093- Large file support is now enabled on Win32 platforms as well as on
1094 Win64. This means that, for example, you can use f.tell() and f.seek()
1095 to manipulate files larger than 2 gigabytes (provided you have enough
1096 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001097 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1098 filesize limit, and large file support makes no difference there.
1099 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1100 NTFS has no practical limit on file size, and files of any size can be
1101 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001102
Tim Petersbdee63f2001-09-02 03:40:59 +00001103- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001104 points to command.com (patch from Brian Quinlan).
1105
Tim Petersedc99312001-08-22 21:36:50 +00001106
Tim Peters20f51a72001-07-21 02:31:40 +00001107What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001108Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001109===========================
1110
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001111Build
1112
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001113- Tim Peters developed a brand new Windows installer using Wise 8.1,
1114 generously donated to us by Wise Solutions.
1115
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001116- configure supports a new option --enable-unicode, with the values
1117 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1118 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001119
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001120- A new configure option --enable-framework builds a Mac OS X framework,
1121 which "make frameworkinstall" will install. This provides a starting
1122 point for more mac-like functionality, join pythonmac-sig@python.org
1123 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001124
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001125- The NeXT platform is no longer supported.
1126
1127- The `new' module is now statically linked.
1128
Tim Peters0afb6092001-08-15 06:06:44 +00001129Tools
1130
1131- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001132 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001133 the module docstring for details.
1134
Tim Peters20f51a72001-07-21 02:31:40 +00001135Tests
1136
Tim Peters5e824c32001-08-12 22:25:01 +00001137- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001138 platforms, allowing to give clearer test result output. regrtest
1139 also has optional --use/-u switch to run normally disabled tests
1140 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001141
Tim Peters20f51a72001-07-21 02:31:40 +00001142- Several new tests in the standard test suite, with special thanks to
1143 Nick Mathewson.
1144
1145Core
1146
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001147- The floor division operator // has been added as outlined in PEP
1148 238. The / operator still provides classic division (and will until
1149 Python 3.0) unless "from __future__ import division" is included, in
1150 which case the / operator will provide true division. The operator
1151 module provides truediv() and floordiv() functions. Augmented
1152 assignment variants are included, as are the equivalent overloadable
1153 methods and C API methods. See the PEP for a full discussion:
1154 <http://python.sf.net/peps/pep-0238.html>
1155
Tim Peters6cd6a822001-08-17 22:11:27 +00001156- Future statements are now effective in simulated interactive shells
1157 (like IDLE). This should "just work" by magic, but read Michael
1158 Hudson's "Future statements in simulated shells" PEP 264 for full
1159 details: <http://python.sf.net/peps/pep-0264.html>.
1160
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001161- The type/class unification (PEP 252-253) was integrated into the
1162 trunk and is not so tentative any more (the exact specification of
1163 some features is still tentative). A lot of work has done on fixing
1164 bugs and adding robustness and features (performance still has to
1165 come a long way).
1166
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001167- Warnings about a mismatch in the Python API during extension import
1168 now use the Python warning framework (which makes it possible to
1169 write filters for these warnings).
1170
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001171- A function's __dict__ (aka func_dict) will now always be a
1172 dictionary. It used to be possible to delete it or set it to None,
1173 but now both actions raise TypeErrors. It is still legal to set it
1174 to a dictionary object. Getting func.__dict__ before any attributes
1175 have been assigned now returns an empty dictionary instead of None.
1176
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001177- A new command line option, -E, was added which disables the use of
1178 all environment variables, or at least those that are specifically
1179 significant to Python. Usually those have a name starting with
1180 "PYTHON". This was used to fix a problem where the tests fail if
1181 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1182 older distribution.
1183
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001184Library
1185
Tim Peters5e824c32001-08-12 22:25:01 +00001186- New class Differ and new functions ndiff() and restore() in difflib.py.
1187 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001188 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001189
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001190- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1191 value using the minimal quoting required for the value; more
1192 reliable than using xml.sax.saxutils.escape() for attribute values.
1193
1194- Readline completion support for cmd.Cmd was added.
1195
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001196- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1197
1198- Added function threading.BoundedSemaphore()
1199
1200- Added Ka-Ping Yee's cgitb.py module.
1201
1202- The `new' module now exposes the CO_xxx flags.
1203
Martin v. Löwis560da622001-11-24 09:24:51 +00001204- The gc module offers the get_referents function.
1205
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001206New platforms
1207
1208C API
1209
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001210- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1211 which provide a cross-platform implementations for the
1212 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1213 the standard sprintf() and vsprintf() C lib APIs, these versions
1214 apply bounds checking on the used buffer which enhances protection
1215 against buffer overruns.
1216
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001217- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001218 and extensions using different Unicode widths is rendered next to
1219 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001220 will result in an ImportError. Unicode extensions writers must make
1221 sure to check the Unicode width compatibility in their extensions by
1222 using at least one of the mangled Unicode APIs in the extension.
1223
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001224- Two new flags METH_NOARGS and METH_O are available in method definition
1225 tables to simplify implementation of methods with no arguments and a
1226 single untyped argument. Calling such methods is more efficient than
1227 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1228 deprecated.
1229
Tim Petersc1731372001-08-04 08:12:36 +00001230Windows
1231
1232- "import module" now compiles module.pyw if it exists and nothing else
1233 relevant is found.
1234
Tim Peters20f51a72001-07-21 02:31:40 +00001235
Guido van Rossum55a78992001-07-17 17:22:32 +00001236What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001237Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001238===========================
1239
1240Core
Tim Petersa814db52001-05-14 07:05:58 +00001241
Tim Peters6d6c1a32001-08-02 04:15:00 +00001242- TENTATIVELY, a large amount of code implementing much of what's
1243 described in PEP 252 (Making Types Look More Like Classes) and PEP
1244 253 (Subtyping Built-in Types) was added. This will be released
1245 with Python 2.2a1. Documentation will be provided separately
1246 through http://www.python.org/2.2/. The purpose of releasing this
1247 with Python 2.2a1 is to test backwards compatibility. It is
1248 possible, though not likely, that a decision is made not to release
1249 this code as part of 2.2 final, if any serious backwards
1250 incompapatibilities are found during alpha testing that cannot be
1251 repaired.
1252
Guido van Rossum55a78992001-07-17 17:22:32 +00001253- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001254 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001255 more 'yield' statements. See PEP 255. Since this adds a new
1256 keyword to the language, this feature must be enabled by including a
1257 future statement: "from __future__ import generators" (see PEP 236).
1258 Generators will become a standard feature in a future release
1259 (probably 2.3). Without this future statement, 'yield' remains an
1260 ordinary identifier, but a warning is issued each time it is used.
1261 (These warnings currently don't conform to the warnings framework of
1262 PEP 230; we intend to fix this in 2.2a2.)
1263
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001264- The UTF-16 codec was modified to be more RFC compliant. It will now
1265 only remove BOM characters at the start of the string and then
1266 only if running in native mode (UTF-16-LE and -BE won't remove a
1267 leading BMO character).
1268
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001269- Strings now have a new method .decode() to complement the already
1270 existing .encode() method. These two methods provide direct access
1271 to the corresponding decoders and encoders of the registered codecs.
1272
1273 To enhance the usability of the .encode() method, the special
1274 casing of Unicode object return values was dropped (Unicode objects
1275 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001276
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001277 Both methods will now return whatever the codec in charge of the
1278 requested encoding returns as object, e.g. Unicode codecs will
1279 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1280 will return u"äöü"). This enables codec writer to create codecs
1281 for various simple to use conversions.
1282
1283 New codecs were added to demonstrate these new features (the .encode()
1284 and .decode() columns indicate the type of the returned objects):
1285
1286 Name | .encode() | .decode() | Description
1287 ----------------------------------------------------------------------
1288 uu | string | string | UU codec (e.g. for email)
1289 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001290 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001291 zlib | string | string | zlib compression
1292 hex | string | string | 2-byte hex codec
1293 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1294
Mark Hammond2a0af792001-05-14 03:09:36 +00001295- Some operating systems now support the concept of a default Unicode
1296 encoding for file system operations. Notably, Windows supports 'mbcs'
1297 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001298 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001299 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001300
1301 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001302 functions that return filenames (such as os.listdir()) to return Python
1303 string objects pre-encoded using the default file system encoding for
1304 the platform. As this encoding is likely to be different from Python's
1305 default encoding, converting this name to a Unicode object before passing
1306 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001307 would attempt to use its default encoding (generally ASCII) rather than
1308 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001309
Tim Petersa814db52001-05-14 07:05:58 +00001310 In general, this change simply removes surprises when working with
1311 Unicode and the file system, making these operations work as you expect,
1312 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001313 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001314
Tim Peters61dff2b2001-05-08 15:43:37 +00001315- Float (and complex) literals in source code were evaluated to full
1316 precision only when running from a .py file; the same code loaded from a
1317 .pyc (or .pyo) file could suffer numeric differences starting at about the
1318 12th significant decimal digit. For example, on a machine with IEEE-754
1319 floating arithmetic,
1320
1321 x = 9007199254740992.0
1322 print long(x)
1323
1324 printed 9007199254740992 if run directly from .py, but 9007199254740000
1325 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1326 str(float) instead of repr(float) when building code objects. marshal
1327 now uses repr(float) instead, which should reproduce floats to full
1328 machine precision (assuming the platform C float<->string I/O conversion
1329 functions are of good quality).
1330
1331 This may cause floating-point results to change in some cases, and
1332 usually for the better, but may also cause numerically unstable
1333 algorithms to break.
1334
Tim Peters2f228e72001-05-13 00:19:31 +00001335- The implementation of dicts suffers fewer collisions, which has speed
1336 benefits. However, the order in which dict entries appear in dict.keys(),
1337 dict.values() and dict.items() may differ from previous releases for a
1338 given dict. Nothing is defined about this order, so no program should
1339 rely on it. Nevertheless, it's easy to write test cases that rely on the
1340 order by accident, typically because of printing the str() or repr() of a
1341 dict to an "expected results" file. See Lib/test/test_support.py's new
1342 sortdict(dict) function for a simple way to display a dict in sorted
1343 order.
1344
Tim Peters7a3bfc32001-06-12 01:22:22 +00001345- Many other small changes to dicts were made, resulting in faster
1346 operation along the most common code paths.
1347
Guido van Rossum10315822001-05-01 20:54:30 +00001348- Dictionary objects now support the "in" operator: "x in dict" means
1349 the same as dict.has_key(x).
1350
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001351- The update() method of dictionaries now accepts generic mapping
1352 objects. Specifically the argument object must support the .keys()
1353 and __getitem__() methods. This allows you to say, for example,
1354 {}.update(UserDict())
1355
Guido van Rossum10315822001-05-01 20:54:30 +00001356- Iterators were added; this is a generalized way of providing values
1357 to a for loop. See PEP 234. There's a new built-in function iter()
1358 to return an iterator. There's a new protocol to get the next value
1359 from an iterator using the next() method (in Python) or the
1360 tp_iternext slot (in C). There's a new protocol to get iterators
1361 using the __iter__() method (in Python) or the tp_iter slot (in C).
1362 Iterating (i.e. a for loop) over a dictionary generates its keys.
1363 Iterating over a file generates its lines.
1364
Tim Petersf553f892001-05-01 20:45:31 +00001365- The following functions were generalized to work nicely with iterator
1366 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001367 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001368 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1369 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001370 join() method of strings
1371 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001372 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1373 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001374 right-hand side of assignment statements with multiple targets, such as
1375 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001376
Tim Petersd85e1022001-05-11 21:51:48 +00001377- Accessing module attributes is significantly faster (for example,
1378 random.random or os.path or yourPythonModule.yourAttribute).
1379
Tim Peterse63415e2001-05-08 04:38:29 +00001380- Comparing dictionary objects via == and != is faster, and now works even
1381 if the keys and values don't support comparisons other than ==.
1382
Tim Peters95bf9392001-05-10 08:32:44 +00001383- Comparing dictionaries in ways other than == and != is slower: there were
1384 insecurities in the dict comparison implementation that could cause Python
1385 to crash if the element comparison routines for the dict keys and/or
1386 values mutated the dicts. Making the code bulletproof slowed it down.
1387
Tim Peterseb28ef22001-06-02 05:27:19 +00001388- Collisions in dicts are resolved via a new approach, which can help
1389 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001390 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001391 faster now. Thanks to Christian Tismer for pointing out the cause and
1392 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001393
Tim Peters52e155e2001-06-16 05:42:57 +00001394- repr() is much faster for large containers (dict, list, tuple).
1395
1396
Tim Petersa814db52001-05-14 07:05:58 +00001397Library
1398
Fred Drake960fdf92001-07-20 18:38:26 +00001399- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1400 were added to the string module. These a locale-indenpendent
1401 constants, unlike letters, lowercase, and uppercase. These are now
1402 use in appropriate locations in the standard library.
1403
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001404- The flags used in dlopen calls can now be configured using
1405 sys.setdlopenflags and queried using sys.getdlopenflags.
1406
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001407- Fredrik Lundh's xmlrpclib is now a standard library module. This
1408 provides full client-side XML-RPC support. In addition,
1409 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1410 one asyncore-based). Thanks to Eric Raymond for the documentation.
1411
Guido van Rossum643d3912001-07-05 14:46:25 +00001412- The xrange() object is simplified: it no longer supports slicing,
1413 repetition, comparisons, efficient 'in' checking, the tolist()
1414 method, or the start, stop and step attributes. See PEP 260.
1415
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001416- A new function fnmatch.filter to filter lists of file names was added.
1417
Barry Warsawffd674d2001-05-22 16:00:10 +00001418- calendar.py uses month and day names based on the current locale.
1419
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001420- strop is now *really* obsolete (this was announced before with 1.6),
1421 and issues DeprecationWarning when used (except for the four items
1422 that are still imported into string.py).
1423
Tim Petersa814db52001-05-14 07:05:58 +00001424- Cookie.py now sorts key+value pairs by key in output strings.
1425
1426- pprint.isrecursive(object) didn't correctly identify recursive objects.
1427 Now it does.
1428
Tim Peters95b3f782001-05-14 18:39:41 +00001429- pprint functions now much faster for large containers (tuple, list, dict).
1430
Tim Peters7b9542a2001-06-10 23:40:19 +00001431- New 'q' and 'Q' format codes in the struct module, corresponding to C
1432 types "long long" and "unsigned long long" (on Windows, __int64). In
1433 native mode, these can be used only when the platform C compiler supports
1434 these types (when HAVE_LONG_LONG is #define'd by the Python config
1435 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001436 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1437 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001438
Guido van Rossum83213cc2001-06-12 16:48:52 +00001439- The site module installs a new built-in function 'help' that invokes
1440 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1441 it displays a message reminding the user to use 'help()' or
1442 'help(object)'.
1443
Tim Petersa814db52001-05-14 07:05:58 +00001444Tests
1445
1446- New test_mutants.py runs dict comparisons where the key and value
1447 comparison operators mutute the dicts randomly during comparison. This
1448 rapidly causes Python to crash under earlier releases (not for the faint
1449 of heart: it can also cause Win9x to freeze or reboot!).
1450
1451- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001452 pprint.isreadable() return sensible results. Also verifies that simple
1453 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001454
Tim Peters4324aa32001-05-28 22:30:08 +00001455C API
1456
1457- Removed the unused last_is_sticky argument from the internal
1458 _PyTuple_Resize(). If this affects you, you were cheating.
1459
1460
Guido van Rossum55a78992001-07-17 17:22:32 +00001461======================================================================
1462
1463
Guido van Rossumffe13be2001-04-16 18:46:45 +00001464What's New in Python 2.1 (final)?
1465=================================
1466
1467We only changed a few things since the last release candidate, all in
1468Python library code:
1469
1470- A bug in the locale module was fixed that affected locales which
1471 define no grouping for numeric formatting.
1472
1473- A few bugs in the weakref module's implementations of weak
1474 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1475 and the test suite was updated to check for these bugs.
1476
1477- An old bug in the os.path.walk() function (introduced in Python
1478 2.0!) was fixed: a non-existent file would cause an exception
1479 instead of being ignored.
1480
1481- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1482 PyChecker.
1483
1484
Guido van Rossum5b08f132001-04-16 02:05:23 +00001485What's New in Python 2.1c2?
1486===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001487
Guido van Rossum5b08f132001-04-16 02:05:23 +00001488A flurry of small changes, and one showstopper fixed in the nick of
1489time made it necessary to release another release candidate. The list
1490here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001491
Guido van Rossum5b08f132001-04-16 02:05:23 +00001492Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001493
Guido van Rossum5b08f132001-04-16 02:05:23 +00001494- Tim discovered a nasty bug in the dictionary code, caused by
1495 PyDict_Next() calling dict_resize(), and the GC code's use of
1496 PyDict_Next() violating an assumption in dict_items(). This was
1497 fixed with considerable amounts of band-aid, but the net effect is a
1498 saner and more robust implementation.
1499
1500- Made a bunch of symbols static that were accidentally global.
1501
1502Build and Ports
1503
1504- The setup.py script didn't check for a new enough version of zlib
1505 (1.1.3 is needed). Now it does.
1506
1507- Changed "make clean" target to also remove shared libraries.
1508
1509- Added a more general warning about the SGI Irix optimizer to README.
1510
1511Library
1512
1513- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1514 omitted the slash between host and file.html.
1515
1516- The mailbox module's _Mailbox class contained a completely broken
1517 and undocumented seek() method. Ripped it out.
1518
1519- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1520 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1521
1522- Fixed a few last-minute bugs in unittest.
1523
1524Extensions
1525
1526- Reverted the patch to the OpenSSL code in socketmodule.c to support
1527 RAND_status() and the EGD, and the subsequent patch that tried to
1528 fix it for pre-0.9.5 versions; the problem with the patch is that on
1529 some systems it issues a warning whenever socket is imported, and
1530 that's unacceptable.
1531
1532Tests
1533
1534- Fixed the pickle tests to work with "import test.test_pickle".
1535
1536- Tweaked test_locale.py to actually run the test Windows.
1537
1538- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1539 not "wb" (which is not a valid mode at all).
1540
1541- Fix pstats browser crashes. Import readline if it exists to make
1542 the user interface nicer.
1543
1544- Add "import thread" to the top of test modules that import the
1545 threading module (test_asynchat and test_threadedtempfile). This
1546 prevents test failures caused by a broken threading module resulting
1547 from a previously caught failed import.
1548
1549- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1550 needed on some platforms (e.g. Solaris 8) when the tests are run
1551 twice in succession.
1552
1553- Skip rather than fail test_sunaudiodev if no audio device is found.
1554
1555
1556What's New in Python 2.1c1?
1557===========================
1558
1559This list was significantly updated when 2.1c2 was released; the 2.1c1
1560release didn't mention most changes that were actually part of 2.1c1:
1561
1562Legal
1563
1564- Copyright was assigned to the Python Software Foundation (PSF) and a
1565 PSF license (very similar to the CNRI license) was added.
1566
1567- The CNRI copyright notice was updated to include 2001.
1568
1569Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001570
Guido van Rossumc9932722001-04-12 02:31:27 +00001571- After a public outcry, assignment to __debug__ is no longer illegal;
1572 instead, a warning is issued. It will become illegal in 2.2.
1573
Guido van Rossum5b08f132001-04-16 02:05:23 +00001574- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1575 "%#x" now always prepends "0x", even if the value is zero.
1576
1577- Fixed some nits in the bytecode compiler.
1578
1579- Fixed core dumps when calling certain kinds of non-functions.
1580
1581- Fixed various core dumps caused by reference count bugs.
1582
1583Build and Ports
1584
1585- Use INSTALL_SCRIPT to install script files.
1586
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001587- New port: SCO Unixware 7, by Billy G. Allie.
1588
Guido van Rossum5b08f132001-04-16 02:05:23 +00001589- Updated RISCOS port.
1590
1591- Updated BeOS port and notes.
1592
1593- Various other porting problems resolved.
1594
1595Library
1596
1597- The TERMIOS and SOCKET modules are now truly obsolete and
1598 unnecessary. Their symbols are incorporated in the termios and
1599 socket modules.
1600
1601- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1602 better tests for pickling.
1603
1604- threading: make Condition.wait() robust against KeyboardInterrupt.
1605
1606- zipfile: add support to zipfile to support opening an archive
1607 represented by an open file rather than a file name. Fix bug where
1608 the archive was not properly closed. Fixed a bug in this bugfix
1609 where flush() was called for a read-only file.
1610
1611- imputil: added an uninstall() method to the ImportManager.
1612
1613- Canvas: fixed bugs in lower() and tkraise() methods.
1614
1615- SocketServer: API change (added overridable close_request() method)
1616 so that the TCP server can explicitly close the request.
1617
1618- pstats: Eric Raymond added a simple interactive statistics browser,
1619 invoked when the module is run as a script.
1620
1621- locale: fixed a problem in format().
1622
1623- webbrowser: made it work when the BROWSER environment variable has a
1624 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1625 KDE 2. Fixed some other nits.
1626
1627- unittest: changes to allow using a different exception than
1628 AssertionError, and added a few more function aliases. Some other
1629 small changes.
1630
1631- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1632
1633- asynchat: fixed a critical bug in asynchat that slipped through the
1634 2.1b2 release. Fixed another rare bug.
1635
1636- Fix some unqualified except: clauses (always a bad code example).
1637
1638XML
1639
1640- pyexpat: new API get_version_string().
1641
1642- Fixed some minidom bugs.
1643
1644Extensions
1645
1646- Fixed a core dump in _weakref. Removed the weakref.mapping()
1647 function (it adds nothing to the API).
1648
1649- Rationalized the use of header files in the readline module, to make
1650 it compile (albeit with some warnings) with the very recent readline
1651 4.2, without breaking for earlier versions.
1652
1653- Hopefully fixed a buffering problem in linuxaudiodev.
1654
1655- Attempted a fix to make the OpenSSL support in the socket module
1656 work again with pre-0.9.5 versions of OpenSSL.
1657
1658Tests
1659
1660- Added a test case for asynchat and asyncore.
1661
1662- Removed coupling between tests where one test failing could break
1663 another.
1664
1665Tools
1666
1667- Ping added an interactive help browser to pydoc, fixed some nits
1668 in the rest of the pydoc code, and added some features to his
1669 inspect module.
1670
1671- An updated python-mode.el version 4.1 which integrates Ken
1672 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1673 much nicer in XEmacs and Emacs. When stepping through your program
1674 with pdb, in either the shell window or the *Python* window, the
1675 source file and line will be tracked by an arrow. Very cool!
1676
1677- IDLE: syntax warnings in interactive mode are changed into errors.
1678
1679- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001680 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001681
1682- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001683
Barry Warsaw11e89c72001-04-11 20:37:57 +00001684
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001685What's New in Python 2.1 beta 2?
1686================================
1687
Guido van Rossum053ae352001-03-22 14:17:21 +00001688(Unlisted are many fixed bugs, more documentation, etc.)
1689
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001690Core language, builtins, and interpreter
1691
Guido van Rossum053ae352001-03-22 14:17:21 +00001692- The nested scopes work (enabled by "from __future__ import
1693 nested_scopes") is completed; in particular, the future now extends
1694 into code executed through exec, eval() and execfile(), and into the
1695 interactive interpreter.
1696
1697- When calling a base class method (e.g. BaseClass.__init__(self)),
1698 this is now allowed even if self is not strictly spoken a class
1699 instance (e.g. when using metaclasses or the Don Beaudry hook).
1700
1701- Slice objects are now comparable but not hashable; this prevents
1702 dict[:] from being accepted but meaningless.
1703
1704- Complex division is now calculated using less braindead algorithms.
1705 This doesn't change semantics except it's more likely to give useful
1706 results in extreme cases. Complex repr() now uses full precision
1707 like float repr().
1708
1709- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1710
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001711- It is illegal to assign to the name __debug__, which is set when the
1712 interpreter starts. It is effectively a compile-time constant.
1713
1714- A warning will be issued if a global statement for a variable
1715 follows a use or assignment of that variable.
1716
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001717Standard library
1718
Guido van Rossum053ae352001-03-22 14:17:21 +00001719- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1720 inspired by JUnit), is now part of the standard library. You now
1721 have a choice of two testing frameworks: unittest requires you to
1722 write testcases as separate code, doctest gathers them from
1723 docstrings. Both approaches have their advantages and
1724 disadvantages.
1725
1726- A new module Tix was added, which wraps the Tix extension library
1727 for Tk. With that module, it is not necessary to statically link
1728 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1729 require" command. See Demo/tix/.
1730
1731- tzparse.py is now obsolete.
1732
1733- In gzip.py, the seek() and tell() methods are removed -- they were
1734 non-functional anyway, and it's better if callers can test for their
1735 existence with hasattr().
1736
1737Python/C API
1738
1739- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1740 that's already in the dictionary during a PyDict_Next() iteration.
1741 This used to fail occasionally when a dictionary resize operation
1742 could be triggered that would rehash all the keys. All other
1743 modifications to the dictionary are still off-limits during a
1744 PyDict_Next() iteration!
1745
1746- New extended APIs related to passing compiler variables around.
1747
1748- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1749 implement isinstance() and issubclass().
1750
1751- Py_BuildValue() now has a "D" conversion to create a Python complex
1752 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001753
Fred Drake4e262a92001-03-22 18:26:47 +00001754- Extensions types which support weak references must now set the
1755 field allocated for the weak reference machinery to NULL themselves;
1756 this is done to avoid the cost of checking each object for having a
1757 weakly referencable type in PyObject_INIT(), since most types are
1758 not weakly referencable.
1759
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001760- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1761 free variables and cell variables to and from the frame's f_locals.
1762
1763- Variants of several functions defined in pythonrun.h have been added
1764 to support the nested_scopes future statement. The variants all end
1765 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1766 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1767 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001768 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001769
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001770Distutils
1771
1772- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1773 into the release tree.
1774
Tim Peters0e57abf2001-05-02 07:39:38 +00001775- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001776 (an uninstaller, more customization of the installer's display)
1777
1778- from Jack Jansen: added Mac-specific code to generate a dialog for
1779 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001780 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001781 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001782
1783- added 'platforms' and 'keywords' to the set of metadata that can be
1784 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001785
1786- applied patches from Jason Tishler to make the compiler class work with
1787 Cygwin.
1788
1789
Tim Peters2fe289a2001-03-01 22:19:38 +00001790What's New in Python 2.1 beta 1?
1791================================
Tim Petersd66595f2001-02-04 03:09:53 +00001792
1793Core language, builtins, and interpreter
1794
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001795- Following an outcry from the community about the amount of code
1796 broken by the nested scopes feature introduced in 2.1a2, we decided
1797 to make this feature optional, and to wait until Python 2.2 (or at
1798 least 6 months) to make it standard. The option can be enabled on a
1799 per-module basis by adding "from __future__ import nested_scopes" at
1800 the beginning of a module (before any other statements, but after
1801 comments and an optional docstring). See PEP 236 (Back to the
1802 __future__) for a description of the __future__ statement. PEP 227
1803 (Statically Nested Scopes) has been updated to reflect this change,
1804 and to clarify the semantics in a number of endcases.
1805
1806- The nested scopes code, when enabled, has been hardened, and most
1807 bugs and memory leaks in it have been fixed.
1808
1809- Compile-time warnings are now generated for a number of conditions
1810 that will break or change in meaning when nested scopes are enabled:
1811
1812 - Using "from...import *" or "exec" without in-clause in a function
1813 scope that also defines a lambda or nested function with one or
1814 more free (non-local) variables. The presence of the import* or
1815 bare exec makes it impossible for the compiler to determine the
1816 exact set of local variables in the outer scope, which makes it
1817 impossible to determine the bindings for free variables in the
1818 inner scope. To avoid the warning about import *, change it into
1819 an import of explicitly name object, or move the import* statement
1820 to the global scope; to avoid the warning about bare exec, use
1821 exec...in... (a good idea anyway -- there's a possibility that
1822 bare exec will be deprecated in the future).
1823
1824 - Use of a global variable in a nested scope with the same name as a
1825 local variable in a surrounding scope. This will change in
1826 meaning with nested scopes: the name in the inner scope will
1827 reference the variable in the outer scope rather than the global
1828 of the same name. To avoid the warning, either rename the outer
1829 variable, or use a global statement in the inner function.
1830
Neil Schemenauera35c6882001-02-27 04:45:05 +00001831- An optional object allocator has been included. This allocator is
1832 optimized for Python objects and should be faster and use less memory
1833 than the standard system allocator. It is not enabled by default
1834 because of possible thread safety problems. The allocator is only
1835 protected by the Python interpreter lock and it is possible that some
1836 extension modules require a thread safe allocator. The object
1837 allocator can be enabled by providing the "--with-pymalloc" option to
1838 configure.
1839
Tim Petersd66595f2001-02-04 03:09:53 +00001840Standard library
1841
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001842- pyexpat now detects the expat version if expat.h defines it. A
1843 number of additional handlers are provided, which are only available
1844 since expat 1.95. In addition, the methods SetParamEntityParsing and
1845 GetInputContext of Parser objects are available with 1.95.x
1846 only. Parser objects now provide the ordered_attributes and
1847 specified_attributes attributes. A new module expat.model was added,
1848 which offers a number of additional constants if 1.95.x is used.
1849
1850- xml.dom offers the new functions registerDOMImplementation and
1851 getDOMImplementation.
1852
1853- xml.dom.minidom offers a toprettyxml method. A number of DOM
1854 conformance issues have been resolved. In particular, Element now
1855 has an hasAttributes method, and the handling of namespaces was
1856 improved.
1857
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001858- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1859 getting information about live Python code, and pydoc.py, a module
1860 for interactively converting docstrings to HTML or text.
1861 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001862 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001863 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1864 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001865
Tim Peters1eff7962001-03-01 02:31:33 +00001866- New library module difflib.py, primarily packaging the SequenceMatcher
1867 class at the heart of the popular ndiff.py file-comparison tool.
1868
1869- doctest.py (a framework for verifying Python code examples in docstrings)
1870 is now part of the std library.
1871
Tim Petersd66595f2001-02-04 03:09:53 +00001872Windows changes
1873
Guido van Rossume3955a82001-03-02 14:05:59 +00001874- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1875 small GUI that lets you browse the module docstrings using your
1876 default web browser.
1877
Tim Peters1eff7962001-03-01 02:31:33 +00001878- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1879 Platforms) is implemented. See
1880
1881 http://python.sourceforge.net/peps/pep-0235.html
1882
1883 for full details, especially the "Current Lower-Left Semantics" section.
1884 The new Windows import rules are simpler than before:
1885
1886 A. If the PYTHONCASEOK environment variable exists, same as
1887 before: silently accept the first case-insensitive match of any
1888 kind; raise ImportError if none found.
1889
1890 B. Else search sys.path for the first case-sensitive match; raise
1891 ImportError if none found.
1892
1893 The same rules have been implented on other platforms with case-
1894 insensitive but case-preserving filesystems too (including Cygwin, and
1895 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001896
Tim Peters25a9ce32001-02-19 07:06:36 +00001897- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1898 what it's supposed to do (and does do under NT and 2000) via direct
1899 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001900 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001901 all Win9x systems before.
1902
Tim Peters1eff7962001-03-01 02:31:33 +00001903- Build: Subproject _test (effectively) renamed to _testcapi.
1904
Tim Peters2fe289a2001-03-01 22:19:38 +00001905New platforms
1906
1907- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1908 Thanks to Steven Majewski!
1909
1910- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1911 Tishler!
1912
Guido van Rossum9089b272001-03-02 06:49:50 +00001913- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1914 Schwertberger! See RISCOS/README for more information -- it seems
1915 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001916 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001917
Tim Peters25a9ce32001-02-19 07:06:36 +00001918
Tim Petersd7b5e882001-01-25 03:36:26 +00001919What's New in Python 2.1 alpha 2?
1920=================================
Tim Peters40ead762001-01-27 05:35:26 +00001921
Tim Petersd7b5e882001-01-25 03:36:26 +00001922Core language, builtins, and interpreter
1923
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001924- Scopes nest. If a name is used in a function or class, but is not
1925 local, the definition in the nearest enclosing function scope will
1926 be used. One consequence of this change is that lambda statements
1927 could reference variables in the namespaces where the lambda is
1928 defined. In some unusual cases, this change will break code.
1929
1930 In all previous version of Python, names were resolved in exactly
1931 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001932 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001933 function A is defined within a function B, the names bound in B are
1934 not visible in A. The new rules make names bound in B visible in A,
1935 unless A contains a name binding that hides the binding in B.
1936
1937 Section 4.1 of the reference manual describes the new scoping rules
1938 in detail. The test script in Lib/test/test_scope.py demonstrates
1939 some of the effects of the change.
1940
1941 The new rules will cause existing code to break if it defines nested
1942 functions where an outer function has local variables with the same
1943 name as globals or builtins used by the inner function. Example:
1944
1945 def munge(str):
1946 def helper(x):
1947 return str(x)
1948 if type(str) != type(''):
1949 str = helper(str)
1950 return str.strip()
1951
1952 Under the old rules, the name str in helper() is bound to the
1953 builtin function str(). Under the new rules, it will be bound to
1954 the argument named str and an error will occur when helper() is
1955 called.
1956
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001957- The compiler will report a SyntaxError if "from ... import *" occurs
1958 in a function or class scope. The language reference has documented
1959 that this case is illegal, but the compiler never checked for it.
1960 The recent introduction of nested scope makes the meaning of this
1961 form of name binding ambiguous. In a future release, the compiler
1962 may allow this form when there is no possibility of ambiguity.
1963
Tim Peters40ead762001-01-27 05:35:26 +00001964- repr(string) is easier to read, now using hex escapes instead of octal,
1965 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1966
1967 >>> "\texample \r\n" + chr(0) + chr(255)
1968 '\texample \r\n\x00\xff' # in 2.1
1969 '\011example \015\012\000\377' # in 2.0
1970
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001971- Functions are now compared and hashed by identity, not by value, since
1972 the func_code attribute is writable.
1973
Fred Drakefb9d7122001-02-01 20:00:40 +00001974- Weak references (PEP 205) have been added. This involves a few
1975 changes in the core, an extension module (_weakref), and a Python
1976 module (weakref). The weakref module is the public interface. It
1977 includes support for "explicit" weak references, proxy objects, and
1978 mappings with weakly held values.
1979
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001980- A 'continue' statement can now appear in a try block within the body
1981 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001982 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001983
Tim Petersd7b5e882001-01-25 03:36:26 +00001984Standard library
1985
Barry Warsaw30dbd142001-01-31 22:14:01 +00001986- mailbox.py now has a new class, PortableUnixMailbox which is
1987 identical to UnixMailbox but uses a more portable scheme for
1988 determining From_ separators. Also, the constructors for all the
1989 classes in this module have a new optional `factory' argument, which
1990 is a callable used when new message classes must be instantiated by
1991 the next() method.
1992
Tim Petersd7b5e882001-01-25 03:36:26 +00001993- random.py is now self-contained, and offers all the functionality of
1994 the now-deprecated whrandom.py. See the docs for details. random.py
1995 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001996 and restoring the internal state of the generator; and jumpahead(n),
1997 for quickly forcing the internal state to be the same as if n calls to
1998 random() had been made. The latter is particularly useful for multi-
1999 threaded programs, creating one instance of the random.Random() class for
2000 each thread, then using .jumpahead() to force each instance to use a
2001 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002002
Tim Peters0de88fc2001-02-01 04:59:18 +00002003- random.py's seed() function is new. For bit-for-bit compatibility with
2004 prior releases, use the whseed function instead. The new seed function
2005 addresses two problems: (1) The old function couldn't produce more than
2006 about 2**24 distinct internal states; the new one about 2**45 (the best
2007 that can be done in the Wichmann-Hill generator). (2) The old function
2008 sometimes produced identical internal states when passed distinct
2009 integers, and there was no simple way to predict when that would happen;
2010 the new one guarantees to produce distinct internal states for all
2011 arguments in [0, 27814431486576L).
2012
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002013- The socket module now supports raw packets on Linux. The socket
2014 family is AF_PACKET.
2015
Tim Peters9ea17ac2001-02-02 05:57:15 +00002016- test_capi.py is a start at running tests of the Python C API. The tests
2017 are implemented by the new Modules/_testmodule.c.
2018
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002019- A new extension module, _symtable, provides provisional access to the
2020 internal symbol table used by the Python compiler. A higher-level
2021 interface will be added on top of _symtable in a future release.
2022
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002023- Removed the obsolete soundex module.
2024
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002025- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2026 the isSameNode method; NamedNodeMap the get method.
2027
2028- xml.sax.expatreader supports the lexical handler property; it
2029 generates comment, startCDATA, and endCDATA events.
2030
Tim Petersee826f82001-01-31 19:39:44 +00002031Windows changes
2032
2033- Build procedure: the zlib project is built in a different way that
2034 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002035 the zlib binary used. See PCbuild\readme.txt for details. Your old
2036 zlib-related directories can be deleted; you'll need to download fresh
2037 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002038
Tim Peters9ea17ac2001-02-02 05:57:15 +00002039- Build: New subproject _test for the benefit of test_capi.py (see above).
2040
Tim Petersb16c56f2001-02-02 21:24:51 +00002041- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2042 interface to some Python compiler internals).
2043
2044- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002045 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002046
Tim Petersa3a3a032000-11-30 05:22:44 +00002047What's New in Python 2.1 alpha 1?
2048=================================
2049
2050Core language, builtins, and interpreter
2051
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002052- There is a new Unicode companion to the PyObject_Str() API
2053 called PyObject_Unicode(). It behaves in the same way as the
2054 former, but assures that the returned value is an Unicode object
2055 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002056
Guido van Rossumf98eda02001-01-17 15:54:45 +00002057- The comparison operators support "rich comparison overloading" (PEP
2058 207). C extension types can provide a rich comparison function in
2059 the new tp_richcompare slot in the type object. The cmp() function
2060 and the C function PyObject_Compare() first try the new rich
2061 comparison operators before trying the old 3-way comparison. There
2062 is also a new C API PyObject_RichCompare() (which also falls back on
2063 the old 3-way comparison, but does not constrain the outcome of the
2064 rich comparison to a Boolean result).
2065
2066 The rich comparison function takes two objects (at least one of
2067 which is guaranteed to have the type that provided the function) and
2068 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2069 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2070 object, which may be NotImplemented (in which case the tp_compare
2071 slot function is used as a fallback, if defined).
2072
2073 Classes can overload individual comparison operators by defining one
2074 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002075 __ge__. There are no explicit "reflected argument" versions of
2076 these; instead, __lt__ and __gt__ are each other's reflection,
2077 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2078 reflection (similar at the C level). No other implications are
2079 made; in particular, Python does not assume that == is the Boolean
2080 inverse of !=, or that < is the Boolean inverse of >=. This makes
2081 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002082
2083 Classes or types that want to implement (in)equality tests but not
2084 the ordering operators (i.e. unordered types) should implement ==
2085 and !=, and raise an error for the ordering operators.
2086
Guido van Rossuma88479f2001-01-18 14:28:08 +00002087 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002088 Boolean; e.g. a matrix type might want to return a matrix of bits
2089 for A < B, giving elementwise comparisons. Such types should ensure
2090 that any interpretation of their value in a Boolean context raises
2091 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2092 at the C level) to always raise an exception.
2093
Guido van Rossuma88479f2001-01-18 14:28:08 +00002094- Complex numbers use rich comparisons to define == and != but raise
2095 an exception for <, <=, > and >=. Unfortunately, this also means
2096 that cmp() of two complex numbers raises an exception when the two
2097 numbers differ. Since it is not mathematically meaningful to compare
2098 complex numbers except for equality, I hope that this doesn't break
2099 too much code.
2100
Tim Peters3389f192001-02-18 08:48:49 +00002101- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002102 not defined by the language, other than that it's arbitrary but
2103 consistent (see the Reference Manual). An implementation detail changed
2104 in 2.1a1 such that None now compares less than any other object. Code
2105 relying on this new behavior (like code that relied on the previous
2106 behavior) does so at its own risk.
2107
Barry Warsaw573b5412001-01-15 20:43:18 +00002108- Functions and methods now support getting and setting arbitrarily
2109 named attributes (PEP 232). Functions have a new __dict__
2110 (a.k.a. func_dict) which hold the function attributes. Methods get
2111 and set attributes on their underlying im_func. It is a TypeError
2112 to set an attribute on a bound method.
2113
Guido van Rossum051e3352001-01-15 19:11:10 +00002114- The xrange() object implementation has been improved so that
2115 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2116 limitation that in this case len(xrange(sys.maxint)) can't be
2117 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2118 work fine as long as the index i doesn't actually reach 2**31.
2119 (Python uses regular ints for sequence and string indices; fixing
2120 that is much more work.)
2121
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002122- Two changes to from...import:
2123
Guido van Rossumba381232001-02-03 15:06:40 +00002124 1) "from M import X" now works even if (after loading module M)
2125 sys.modules['M'] is not a real module; it's basically a getattr()
2126 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002127
2128 2) "from M import *" now looks for M.__all__ to decide which names to
2129 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2130 filters out names starting with '_' as before. Whether or not
2131 __all__ exists, there's no restriction on the type of M.
2132
Guido van Rossumf61f1662001-01-10 20:13:55 +00002133- File objects have a new method, xreadlines(). This is the fastest
2134 way to iterate over all lines in a file:
2135
2136 for line in file.xreadlines():
2137 ...do something to line...
2138
2139 See the xreadlines module (mentioned below) for how to do this for
2140 other file-like objects.
2141
2142- Even if you don't use file.xreadlines(), you may expect a speedup on
2143 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002144 quite a bit in platform-specific ways: on systems (like Linux) that
2145 support flockfile(), getc_unlocked(), and funlockfile(), those are
2146 used by default. On systems (like Windows) without getc_unlocked(),
2147 a complicated (but still thread-safe) method using fgets() is used by
2148 default.
2149
Tim Petersd52269b2001-01-25 06:23:18 +00002150 You can force use of the fgets() method by #define'ing
2151 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002152 getc_unlocked()).
2153
Tim Petersd52269b2001-01-25 06:23:18 +00002154 You can force fgets() not to be used by #define'ing
2155 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002156 test_bufio.py fails -- and let us know if it does!).
2157
2158- In addition, the fileinput module, while still slower than the other
2159 methods on most platforms, has been sped up too, by using
2160 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002161
2162- Support for run-time warnings has been added, including a new
2163 command line option (-W) to specify the disposition of warnings.
2164 See the description of the warnings module below.
2165
2166- Extensive changes have been made to the coercion code. This mostly
2167 affects extension modules (which can now implement mixed-type
2168 numerical operators without having to use coercion), but
2169 occasionally, in boundary cases the coercion semantics have changed
2170 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002171 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002172 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002173 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002174
Guido van Rossumf98eda02001-01-17 15:54:45 +00002175- In connection with the coercion changes, a new built-in singleton
2176 object, NotImplemented is defined. This can be returned for
2177 operations that wish to indicate they are not implemented for a
2178 particular combination of arguments. From C, this is
2179 Py_NotImplemented.
2180
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002181- The interpreter accepts now bytecode files on the command line even
2182 if they do not have a .pyc or .pyo extension. On Linux, after executing
2183
Martin v. Löwise214baa2001-02-04 22:37:56 +00002184import imp,sys,string
2185magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2186reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2187open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002188
2189 any byte code file can be used as an executable (i.e. as an argument
2190 to execve(2)).
2191
Tim Peters9940b802000-12-01 07:59:35 +00002192- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002193 character. In 1.6 and earlier, they never produced a sign,
2194 and raised an error if the value of the long was too large
2195 to fit in a Python int. In 2.0, they produced a sign if and
2196 only if too large to fit in an int. This was inconsistent
2197 across platforms (because the size of an int varies across
2198 platforms), and inconsistent with hex() and oct(). Example:
2199
2200 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002201 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002202 'ffffffbe' # in 2.0 and before, on 32-bit machines
2203 >>> hex(-0x42L)
2204 '-0x42L' # in all versions of Python
2205
Tim Peters9940b802000-12-01 07:59:35 +00002206 The behavior of %d formats for negative Python longs remains
2207 the same as in 2.0 (although in 1.6 and before, they raised
2208 an error if the long didn't fit in a Python int).
2209
2210 %u formats don't make sense for Python longs, but are allowed
2211 and treated the same as %d in 2.1. In 2.0, a negative long
2212 formatted via %u produced a sign if and only if too large to
2213 fit in an int. In 1.6 and earlier, a negative long formatted
2214 via %u raised an error if it was too big to fit in an int.
2215
Guido van Rossum3661d392000-12-12 22:10:31 +00002216- Dictionary objects have an odd new method, popitem(). This removes
2217 an arbitrary item from the dictionary and returns it (in the form of
2218 a (key, value) pair). This can be useful for algorithms that use a
2219 dictionary as a bag of "to do" items and repeatedly need to pick one
2220 item. Such algorithms normally end up running in quadratic time;
2221 using popitem() they can usually be made to run in linear time.
2222
Tim Peters36cdad12000-12-29 02:06:45 +00002223Standard library
2224
Thomas Woutersfe385252001-01-19 23:16:56 +00002225- In the time module, the time argument to the functions strftime,
2226 localtime, gmtime, asctime and ctime is now optional, defaulting to
2227 the current time (in the local timezone).
2228
Guido van Rossumda91f222001-01-15 16:36:08 +00002229- The ftplib module now defaults to passive mode, which is deemed a
2230 more useful default given that clients are often inside firewalls
2231 these days. Note that this could break if ftplib is used to connect
2232 to a *server* that is inside a firewall, from outside; this is
2233 expected to be a very rare situation. To fix that, you can call
2234 ftp.set_pasv(0).
2235
Martin v. Löwis10a27872001-01-13 09:54:41 +00002236- The module site now treats .pth files not only for path configuration,
2237 but also supports extensions to the initialization code: Lines starting
2238 with import are executed.
2239
Guido van Rossumf61f1662001-01-10 20:13:55 +00002240- There's a new module, warnings, which implements a mechanism for
2241 issuing and filtering warnings. There are some new built-in
2242 exceptions that serve as warning categories, and a new command line
2243 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2244 turns warnings into errors). warnings.warn(message[, category])
2245 issues a warning message; this can also be called from C as
2246 PyErr_Warn(category, message).
2247
2248- A new module xreadlines was added. This exports a single factory
2249 function, xreadlines(). The intention is that this code is the
2250 absolutely fastest way to iterate over all lines in an open
2251 file(-like) object:
2252
2253 import xreadlines
2254 for line in xreadlines.xreadlines(file):
2255 ...do something to line...
2256
2257 This is equivalent to the previous the speed record holder using
2258 file.readlines(sizehint). Note that if file is a real file object
2259 (as opposed to a file-like object), this is equivalent:
2260
2261 for line in file.xreadlines():
2262 ...do something to line...
2263
Tim Peters36cdad12000-12-29 02:06:45 +00002264- The bisect module has new functions bisect_left, insort_left,
2265 bisect_right and insort_right. The old names bisect and insort
2266 are now aliases for bisect_right and insort_right. XXX_right
2267 and XXX_left methods differ in what happens when the new element
2268 compares equal to one or more elements already in the list: the
2269 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002270 right. Code that doesn't care where equal elements end up should
2271 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002272
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002273- The new curses.panel module wraps the panel library that forms part
2274 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2275
Guido van Rossumf61f1662001-01-10 20:13:55 +00002276- The SocketServer module now sets the allow_reuse_address flag by
2277 default in the TCPServer class.
2278
2279- A new function, sys._getframe(), returns the stack frame pointer of
2280 the caller. This is intended only as a building block for
2281 higher-level mechanisms such as string interpolation.
2282
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002283- The pyexpat module supports a number of new handlers, which are
2284 available only in expat 1.2. If invocation of a callback fails, it
2285 will report an additional frame in the traceback. Parser objects
2286 participate now in garbage collection. If expat reports an unknown
2287 encoding, pyexpat will try to use a Python codec; that works only
2288 for single-byte charsets. The parser type objects is exposed as
2289 XMLParserObject.
2290
2291- xml.dom now offers standard definitions for symbolic node type and
2292 exception code constants, and a hierarchy of DOM exceptions. minidom
2293 was adjusted to use them.
2294
2295- The conformance of xml.dom.minidom to the DOM specification was
2296 improved. It detects a number of additional error cases; the
2297 previous/next relationship works even when the tree is modified;
2298 Node supports the normalize() method; NamedNodeMap, DocumentType and
2299 DOMImplementation classes were added; Element supports the
2300 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2301 method.
2302
Guido van Rossumf61f1662001-01-10 20:13:55 +00002303Build issues
2304
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002305- For Unix (and Unix-compatible) builds, configuration and building of
2306 extension modules is now greatly automated. Rather than having to
2307 edit the Modules/Setup file to indicate which modules should be
2308 built and where their include files and libraries are, a
2309 distutils-based setup.py script now takes care of building most
2310 extension modules. All extension modules built this way are built
2311 as shared libraries. Only a few modules that must be linked
2312 statically are still listed in the Setup file; you won't need to
2313 edit their configuration.
2314
2315- Python should now build out of the box on Cygwin. If it doesn't,
2316 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002317
2318- Python now always uses its own (renamed) implementation of getopt()
2319 -- there's too much variation among C library getopt()
2320 implementations.
2321
2322- C++ compilers are better supported; the CXX macro is always set to a
2323 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002324
Tim Petersd92dfe02000-12-12 01:18:41 +00002325Windows changes
2326
2327- select module: By default under Windows, a select() call
2328 can specify no more than 64 sockets. Python now boosts
2329 this Microsoft default to 512. If you need even more than
2330 that, see the MS docs (you'll need to #define FD_SETSIZE
2331 and recompile Python from source).
2332
Guido van Rossumf61f1662001-01-10 20:13:55 +00002333- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2334 subdirectory is no more!
2335
Tim Petersa3a3a032000-11-30 05:22:44 +00002336
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002337What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002338=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002339
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002340Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002341changes are in the file HISTORY. If you are making the jump directly
2342from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2343HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002344
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002345Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2346the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2347http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002348
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002349--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002350
2351======================================================================
2352
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002353What's new in 2.0 (since release candidate 1)?
2354==============================================
2355
2356Standard library
2357
2358- The copy_reg module was modified to clarify its intended use: to
2359 register pickle support for extension types, not for classes.
2360 pickle() will raise a TypeError if it is passed a class.
2361
2362- Fixed a bug in gettext's "normalize and expand" code that prevented
2363 it from finding an existing .mo file.
2364
2365- Restored support for HTTP/0.9 servers in httplib.
2366
Tim Peters989b7b92000-10-16 20:24:53 +00002367- The math module was changed to stop raising OverflowError in case of
2368 underflow, and return 0 instead in underflow cases. Whether Python
2369 used to raise OverflowError in case of underflow was platform-
2370 dependent (it did when the platform math library set errno to ERANGE
2371 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002372
2373- Fixed a bug in StringIO that occurred when the file position was not
2374 at the end of the file and write() was called with enough data to
2375 extend past the end of the file.
2376
2377- Fixed a bug that caused Tkinter error messages to get lost on
2378 Windows. The bug was fixed by replacing direct use of
2379 interp->result with Tcl_GetStringResult(interp).
2380
2381- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2382 redirect response.
2383
2384- Several changes were made to distutils: Some debugging code was
2385 removed from util. Fixed the installer used when an external zip
2386 program (like WinZip) is not found; the source code for this
2387 installer is in Misc/distutils. check_lib() was modified to behave
2388 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2389 test for whether installed modules are on sys.path was changed to
2390 use both normcase() and normpath().
2391
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002392- Several minor bugs were fixed in the xml package (the minidom,
2393 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002394
2395- The regression test driver (regrtest.py) behavior when invoked with
2396 -l changed: It now reports a count of objects that are recognized as
2397 garbage but not freed by the garbage collector.
2398
Tim Peters989b7b92000-10-16 20:24:53 +00002399- The regression test for the math module was changed to test
2400 exceptional behavior when the test is run in verbose mode. Python
2401 cannot yet guarantee consistent exception behavior across platforms,
2402 so the exception part of test_math is run only in verbose mode, and
2403 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002404
2405Internals
2406
2407- PyOS_CheckStack() has been disabled on Win64, where it caused
2408 test_sre to fail.
2409
2410Build issues
2411
2412- Changed compiler flags, so that gcc is always invoked with -Wall and
2413 -Wstrict-prototypes. Users compiling Python with GCC should see
2414 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002415 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002416 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002417
Tim Petersa3a3a032000-11-30 05:22:44 +00002418- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002419
2420Tools and other miscellany
2421
2422- The compiler in Tools/compiler was updated to support the new
2423 language features introduced in 2.0: extended print statement, list
2424 comprehensions, and augmented assignments. The new compiler should
2425 also be backwards compatible with Python 1.5.2; the compiler will
2426 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002427 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002428
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002429What's new in 2.0 release candidate 1 (since beta 2)?
2430=====================================================
2431
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002432What is release candidate 1?
2433
2434We believe that release candidate 1 will fix all known bugs that we
2435intend to fix for the 2.0 final release. This release should be a bit
2436more stable than the previous betas. We would like to see even more
2437widespread testing before the final release, so we are producing this
2438release candidate. The final release will be exactly the same unless
2439any show-stopping (or brown bag) bugs are found by testers of the
2440release candidate.
2441
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002442All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002443to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002444
2445Core language, builtins, and interpreter
2446
2447- A bug that caused crashes when __coerce__ was used with augmented
2448 assignment, e.g. +=, was fixed.
2449
2450- Raise ZeroDivisionError when raising zero to a negative number,
2451 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2452 power operator and the result of math.pow(0.0, -2.0) will vary by
2453 platform. On Linux, it raises a ValueError.
2454
2455- A bug in Unicode string interpolation was fixed that occasionally
2456 caused errors with formats including "%%". For example, the
2457 following expression "%% %s" % u"abc" no longer raises a TypeError.
2458
2459- Compilation of deeply nested expressions raises MemoryError instead
2460 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2461
2462- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2463 rendering them useless. They are now written in binary mode again.
2464
2465Standard library
2466
2467- Keyword arguments are now accepted for most pattern and match object
2468 methods in SRE, the standard regular expression engine.
2469
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002470- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002471 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002472
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002473- Several bugs in the Unicode handling and error handling in _tkinter
2474 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002475
2476- Fix memory management errors in Merge() and Tkapp_Call() routines.
2477
2478- Several changes were made to cStringIO to make it compatible with
2479 the file-like object interface and with StringIO. If operations are
2480 performed on a closed object, an exception is raised. The truncate
2481 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002482 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002483
2484- There were many changes made to the linuxaudiodev module and its
2485 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002486 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002487
2488 Note that this module is named poorly, because it should work
2489 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002490 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002491
2492 The module now raises exceptions when errors occur instead of
2493 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2494 audio) and defines a getptr() method that calls the
2495 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2496
2497- The library_version attribute, introduced in an earlier beta, was
2498 removed because it can not be supported with early versions of the C
2499 readline library, which provides no way to determine the version at
2500 compile-time.
2501
2502- The binascii module is now enabled on Win64.
2503
Tim Peters46446d62000-10-09 21:19:31 +00002504- tokenize.py no longer suffers "recursion depth" errors when parsing
2505 programs with very long string literals.
2506
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002507Internals
2508
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002509- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002510 which is called when the interpreter starts up to determine where
2511 the standard library is installed. These vulnerabilities affect all
2512 previous versions of Python and can be exploited by setting very
2513 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2514 setuid Python script, although use of the wrapper in
2515 Misc/setuid-prog.c will eliminate the vulnerability.
2516
2517- Fixed garbage collection bugs in instance creation that were
2518 triggered when errors occurred during initialization. The solution,
2519 applied in cPickle and in PyInstance_New(), is to call
2520 PyObject_GC_Init() after the initialization of the object's
2521 container attributes is complete.
2522
2523- pyexpat adds definitions of PyModule_AddStringConstant and
2524 PyModule_AddObject if the Python version is less than 2.0, which
2525 provides compatibility with PyXML on Python 1.5.2.
2526
2527- If the platform has a bogus definition for LONG_BIT (the number of
2528 bits in a long), an error will be reported at compile time.
2529
2530- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2531 collection crashes and possibly other, unreported crashes.
2532
2533- Fixed a memory leak in _PyUnicode_Fini().
2534
2535Build issues
2536
2537- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002538 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002539 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002540
2541- The mmap.PAGESIZE constant is now initialized using sysconf when
2542 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2543
2544- The md5 file should now compile on all platforms.
2545
2546- The select module now compiles on platforms that do not define
2547 POLLRDNORM and related constants.
2548
2549- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002550 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002551
Jeremy Hylton10921202000-10-09 18:34:12 +00002552- BeOS: A number of changes were made to the build and installation
2553 process. ar-fake now operates on a directory of object files.
2554 dl_export.h is gone, and its macros now appear on the mwcc command
2555 line during build on PPC BeOS.
2556
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002557- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002558 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002559
2560- Cygwin: Support for shared libraries, Tkinter, and sockets.
2561
2562- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2563
2564Tools and other miscellany
2565
2566- Removed debugging prints from main used with freeze.
2567
Tim Peters46446d62000-10-09 21:19:31 +00002568- IDLE auto-indent no longer crashes when it encounters Unicode
2569 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002570
2571What's new in 2.0 beta 2 (since beta 1)?
2572========================================
2573
2574Core language, builtins, and interpreter
2575
Tim Peters482c0212000-09-26 06:33:09 +00002576- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002577 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002578
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002579- Add -h and -V command line options to print the usage message and
2580 Python version number and exit immediately.
2581
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002582- eval() and exec accept Unicode objects as code parameters.
2583
2584- getattr() and setattr() now also accept Unicode objects for the
2585 attribute name, which are converted to strings using the default
2586 encoding before lookup.
2587
2588- Multiplication on string and Unicode now does proper bounds
2589 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2590 string is too long."
2591
2592- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002593 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002594
Jeremy Hylton1b618592000-09-26 05:32:36 +00002595
2596Standard library and extensions
2597
Guido van Rossum5b08f132001-04-16 02:05:23 +00002598- socket module: the OpenSSL code now adds support for RAND_status()
2599 and EGD (Entropy Gathering Device).
2600
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002601- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002602 argument checking; it still takes no arguments.
2603
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002604- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002605
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002606- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002607
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002608- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002609
2610- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002611 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002612
2613- copy: Copy Unicode objects atomically.
2614
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002615- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002616
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002617- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002618
Fred Drake67233bc2000-09-26 16:40:27 +00002619- dbm: Add get() and setdefault() methods to dbm object. Add constant
2620 `library' to module that names the library used. Added doc strings
2621 and method names to error messages. Uses configure to determine
2622 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2623 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002624
2625- distutils: Update to version 0.9.3.
2626
2627- dl: Add several dl.RTLD_ constants.
2628
2629- fpectl: Now supported on FreeBSD.
2630
2631- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2632 found by the collector will be saved in gc.garbage. This is useful
2633 for debugging a program that creates reference cycles.
2634
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002635- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002636 of HTTP class. Do not close socket on zero-length response. Do not
2637 crash when server sends invalid content-length header.
2638
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002639- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002640
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002641- marshal: When reading a short, sign-extend on platforms where shorts
2642 are bigger than 16 bits. When reading a long, repair the unportable
2643 sign extension that was being done for 64-bit machines. (It assumed
2644 that signed right shift sign-extends.)
2645
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002646- operator: Add contains(), invert(), __invert__() as aliases for
2647 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002648
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002649- os: Add support for popen2() and popen3() on all platforms where
2650 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002651
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002652- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002653 clicking on a file in Explorer (or passing the file name to the
2654 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002655
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002656- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002657 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002658
2659- pickle: Now raises ValueError when an invalid pickle that contains
2660 a non-string repr where a string repr was expected. This behavior
2661 matches cPickle.
2662
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002663- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002664
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002665- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002666
2667- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002668 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002669 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002670
2671- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002672 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002673
2674- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002675 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002676 few cycles during startup since the first call to
2677 setdefaultencoding() will initialize the codec registry and the
2678 encodings package.
2679
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002680- socket: Support for size hint in readlines() method of object returned
2681 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002682
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002683- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002684 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002685 is followed by whitespace.
2686
Tim Petersa3a3a032000-11-30 05:22:44 +00002687- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002688
2689- struct: Check ranges for bytes and shorts.
2690
2691- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002692 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002693
2694- Tkinter: Image objects are now guaranteed to have unique ids. Set
2695 event.delta to zero if Tk version doesn't support mousewheel.
2696 Removed some debugging prints.
2697
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002698- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002699
Fred Drake67233bc2000-09-26 16:40:27 +00002700- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002701 which works around a bug in Norton AntiVirus 2000 that leads directly
2702 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002703
2704- xml: New version detection code allows PyXML to override standard
2705 XML package if PyXML version is greater than 0.6.1.
2706
Fred Drake64bb3802000-09-26 16:21:35 +00002707- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2708 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2709 tree only for nodes which are sufficiently interesting to a specific
2710 application. Does not provide the HTML-specific extensions. Still
2711 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002712
Fred Drake64bb3802000-09-26 16:21:35 +00002713- xml.sax: SAX 2 support for Python, including all the handler
2714 interfaces needed to process XML 1.0 compliant XML. Some
2715 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002716
Fred Drake64bb3802000-09-26 16:21:35 +00002717- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2718 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002719
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002720
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721C API
2722
2723- Add three new convenience functions for module initialization --
2724 PyModule_AddObject(), PyModule_AddIntConstant(), and
2725 PyModule_AddStringConstant().
2726
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002727- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002728 removed and add #error to Python.h if NULL isn't defined after
2729 #include of stdio.h.
2730
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002731- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002732 backwards compatibility (at the source level) with old extensions.
2733
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002734- A wrapper API was added for signal() and sigaction(). Instead of
2735 either function, always use PyOS_getsig() to get a signal handler
2736 and PyOS_setsig() to set one. A new convenience typedef
2737 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002738
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002739- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002740 internal data buffer and size of a string object -- or the default
2741 encoded version of a Unicode object.
2742
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002743- PyString_Size() and PyString_AsString() accept Unicode objects.
2744
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002745- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002746 exists). INT_MAX and LONG_MAX will always be defined, even if
2747 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002748
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002749- PyFloat_FromString takes a second argument, pend, that was
2750 effectively useless. It is now officially useless but preserved for
2751 backwards compatibility. If the pend argument is not NULL, *pend is
2752 set to NULL.
2753
2754- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2755 for the attribute name. See note on getattr() above.
2756
2757- A few bug fixes to argument processing for Unicode.
2758 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2759 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2760 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002761 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002762
2763- Py_BuildValue accepts B format (for bgen-generated code).
2764
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002765
Jeremy Hylton1b618592000-09-26 05:32:36 +00002766Internals
2767
2768- On Unix, fix code for finding Python installation directory so that
2769 it works when argv[0] is a relative path.
2770
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002771- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002772 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002773 rather than by generating a copy of the object.
2774
Tim Peters482c0212000-09-26 06:33:09 +00002775- Several of the internal Unicode tables are much smaller now, and
2776 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002777
Jeremy Hylton97693b02000-09-26 17:42:51 +00002778- In the garbage collector: Fixed bug in collection of tuples. Fixed
2779 bug that caused some instances to be removed from the container set
2780 while they were still live. Fixed parsing in gc.set_debug() for
2781 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002782
2783- Fixed refcount problem in instance deallocation that only occurred
2784 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2785
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002786- On Windows, getpythonregpath is now protected against null data in
2787 registry key.
2788
2789- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002790 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002791
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002792
Jeremy Hylton1b618592000-09-26 05:32:36 +00002793Build and platform-specific issues
2794
2795- Better support of GNU Pth via --with-pth configure option.
2796
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002797- Python/C API now properly exposed to dynamically-loaded extension
2798 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002799
2800- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2801 Don't define MS_SYNC to be zero when it is undefined. Added missing
2802 prototypes in posixmodule.c.
2803
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002804- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002805 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002806
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002807- Fix largefile support on older NetBSD systems and OpenBSD by adding
2808 define for TELL64.
2809
2810
2811Tools and other miscellany
2812
2813- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2814
2815- freeze: The modulefinder now works with 2.0 opcodes.
2816
Tim Petersa3a3a032000-11-30 05:22:44 +00002817- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002818 Move hackery of sys.argv until after the Tk instance has been
2819 created, which allows the application-specific Tkinter
2820 initialization to be executed if present; also pass an explicit
2821 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002822
Jeremy Hylton1b618592000-09-26 05:32:36 +00002823
2824What's new in 2.0 beta 1?
2825=========================
2826
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002827Source Incompatibilities
2828------------------------
2829
2830None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2831such as single-argument append(), connect() and bind(), and changes to
2832str(long) and repr(float).
2833
2834
2835Binary Incompatibilities
2836------------------------
2837
2838- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2839with Python 2.0; these extensions will have to be rebuilt for Python
28402.0.
2841
2842- On Windows, attempting to import a third party extension built for
2843Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2844can do about this. Check your PYTHONPATH environment variable!
2845
2846- Python bytecode files (*.pyc and *.pyo) are not compatible between
2847releases.
2848
2849
2850Overview of Changes Since 1.6
2851-----------------------------
2852
2853There are many new modules (including brand new XML support through
2854the xml package, and i18n support through the gettext module); a list
2855of all new modules is included below. Lots of bugs have been fixed.
2856
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002857The process for making major new changes to the language has changed
2858since Python 1.6. Enhancements must now be documented by a Python
2859Enhancement Proposal (PEP) before they can be accepted.
2860
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002861There are several important syntax enhancements, described in more
2862detail below:
2863
2864 - Augmented assignment, e.g. x += 1
2865
2866 - List comprehensions, e.g. [x**2 for x in range(10)]
2867
2868 - Extended import statement, e.g. import Module as Name
2869
2870 - Extended print statement, e.g. print >> file, "Hello"
2871
2872Other important changes:
2873
2874 - Optional collection of cyclical garbage
2875
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002876Python Enhancement Proposal (PEP)
2877---------------------------------
2878
2879PEP stands for Python Enhancement Proposal. A PEP is a design
2880document providing information to the Python community, or describing
2881a new feature for Python. The PEP should provide a concise technical
2882specification of the feature and a rationale for the feature.
2883
2884We intend PEPs to be the primary mechanisms for proposing new
2885features, for collecting community input on an issue, and for
2886documenting the design decisions that have gone into Python. The PEP
2887author is responsible for building consensus within the community and
2888documenting dissenting opinions.
2889
2890The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002891
2892Augmented Assignment
2893--------------------
2894
2895This must have been the most-requested feature of the past years!
2896Eleven new assignment operators were added:
2897
Guido van Rossume905e952000-09-05 12:42:46 +00002898 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002899
2900For example,
2901
2902 A += B
2903
2904is similar to
2905
2906 A = A + B
2907
2908except that A is evaluated only once (relevant when A is something
2909like dict[index].attr).
2910
2911However, if A is a mutable object, A may be modified in place. Thus,
2912if A is a number or a string, A += B has the same effect as A = A+B
2913(except A is only evaluated once); but if a is a list, A += B has the
2914same effect as A.extend(B)!
2915
2916Classes and built-in object types can override the new operators in
2917order to implement the in-place behavior; the not-in-place behavior is
2918used automatically as a fallback when an object doesn't implement the
2919in-place behavior. For classes, the method name is derived from the
2920method name for the corresponding not-in-place operator by inserting
2921an 'i' in front of the name, e.g. __iadd__ implements in-place
2922__add__.
2923
2924Augmented assignment was implemented by Thomas Wouters.
2925
2926
2927List Comprehensions
2928-------------------
2929
2930This is a flexible new notation for lists whose elements are computed
2931from another list (or lists). The simplest form is:
2932
2933 [<expression> for <variable> in <sequence>]
2934
Guido van Rossum56db0952000-09-06 23:34:25 +00002935For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002936This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002937
2938You can also add a condition:
2939
2940 [<expression> for <variable> in <sequence> if <condition>]
2941
2942For example, [w for w in words if w == w.lower()] would yield the list
2943of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002944than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002945
2946You can also have nested for loops and more than one 'if' clause. For
2947example, here's a function that flattens a sequence of sequences::
2948
2949 def flatten(seq):
2950 return [x for subseq in seq for x in subseq]
2951
2952 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2953
2954This prints
2955
2956 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2957
2958List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002959Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002960
2961
2962Extended Import Statement
2963-------------------------
2964
2965Many people have asked for a way to import a module under a different
2966name. This can be accomplished like this:
2967
2968 import foo
2969 bar = foo
2970 del foo
2971
2972but this common idiom gets old quickly. A simple extension of the
2973import statement now allows this to be written as follows:
2974
2975 import foo as bar
2976
2977There's also a variant for 'from ... import':
2978
2979 from foo import bar as spam
2980
2981This also works with packages; e.g. you can write this:
2982
2983 import test.regrtest as regrtest
2984
2985Note that 'as' is not a new keyword -- it is recognized only in this
2986context (this is only possible because the syntax for the import
2987statement doesn't involve expressions).
2988
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002989Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002990
2991
2992Extended Print Statement
2993------------------------
2994
2995Easily the most controversial new feature, this extension to the print
2996statement adds an option to make the output go to a different file
2997than the default sys.stdout.
2998
2999For example, to write an error message to sys.stderr, you can now
3000write:
3001
3002 print >> sys.stderr, "Error: bad dog!"
3003
3004As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003005evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003006
3007 print >> None, "Hello world"
3008
3009is equivalent to
3010
3011 print "Hello world"
3012
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003013Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003014
3015
3016Optional Collection of Cyclical Garbage
3017---------------------------------------
3018
3019Python is now equipped with a garbage collector that can hunt down
3020cyclical references between Python objects. It's no replacement for
3021reference counting; in fact, it depends on the reference counts being
3022correct, and decides that a set of objects belong to a cycle if all
3023their reference counts can be accounted for from their references to
3024each other. This devious scheme was first proposed by Eric Tiedemann,
3025and brought to implementation by Neil Schemenauer.
3026
3027There's a module "gc" that lets you control some parameters of the
3028garbage collection. There's also an option to the configure script
3029that lets you enable or disable the garbage collection. In 2.0b1,
3030it's on by default, so that we (hopefully) can collect decent user
3031experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003032performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003033off by default in the final 2.0 release.
3034
3035
3036Smaller Changes
3037---------------
3038
3039A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3040map(None, seq1, seq2, ...) when the sequences have the same length;
3041i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3042the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003043zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003044
3045sys.version_info is a tuple (major, minor, micro, level, serial).
3046
3047Dictionaries have an odd new method, setdefault(key, default).
3048dict.setdefault(key, default) returns dict[key] if it exists; if not,
3049it sets dict[key] to default and returns that value. Thus:
3050
3051 dict.setdefault(key, []).append(item)
3052
3053does the same work as this common idiom:
3054
3055 if not dict.has_key(key):
3056 dict[key] = []
3057 dict[key].append(item)
3058
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003059There are two new variants of SyntaxError that are raised for
3060indentation-related errors: IndentationError and TabError.
3061
3062Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3063escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003064
3065The limits on the size of expressions and file in Python source code
3066have been raised from 2**16 to 2**32. Previous versions of Python
3067were limited because the maximum argument size the Python VM accepted
3068was 2**16. This limited the size of object constructor expressions,
3069e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3070limit was raised thanks to a patch by Charles Waldman that effectively
3071fixes the problem. It is now much more likely that you will be
3072limited by available memory than by an arbitrary limit in Python.
3073
3074The interpreter's maximum recursion depth can be modified by Python
3075programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3076limit is the maximum number of recursive calls that can be made by
3077Python code. The limit exists to prevent infinite recursion from
3078overflowing the C stack and causing a core dump. The default value is
30791000. The maximum safe value for a particular platform can be found
3080by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003081
3082New Modules and Packages
3083------------------------
3084
3085atexit - for registering functions to be called when Python exits.
3086
3087imputil - Greg Stein's alternative API for writing custom import
3088hooks.
3089
3090pyexpat - an interface to the Expat XML parser, contributed by Paul
3091Prescod.
3092
3093xml - a new package with XML support code organized (so far) in three
3094subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3095would fill a volume. There's a special feature whereby a
3096user-installed package named _xmlplus overrides the standard
3097xmlpackage; this is intended to give the XML SIG a hook to distribute
3098backwards-compatible updates to the standard xml package.
3099
3100webbrowser - a platform-independent API to launch a web browser.
3101
3102
Guido van Rossume905e952000-09-05 12:42:46 +00003103Changed Modules
3104---------------
3105
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003106array -- new methods for array objects: count, extend, index, pop, and
3107remove
3108
3109binascii -- new functions b2a_hex and a2b_hex that convert between
3110binary data and its hex representation
3111
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003112calendar -- Many new functions that support features including control
3113over which day of the week is the first day, returning strings instead
3114of printing them. Also new symbolic constants for days of week,
3115e.g. MONDAY, ..., SUNDAY.
3116
3117cgi -- FieldStorage objects have a getvalue method that works like a
3118dictionary's get method and returns the value attribute of the object.
3119
3120ConfigParser -- The parser object has new methods has_option,
3121remove_section, remove_option, set, and write. They allow the module
3122to be used for writing config files as well as reading them.
3123
3124ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003125optionally support the RFC 959 REST command.
3126
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003127gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003128
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003129httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3130the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003131
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003132locale -- implement getdefaultlocale for Win32 and Macintosh
3133
3134marshal -- no longer dumps core when marshaling deeply nested or
3135recursive data structures
3136
3137os -- new functions isatty, seteuid, setegid, setreuid, setregid
3138
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003139os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3140support under Unix.
3141
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003142os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003143
3144os.path -- fix semantics of os.path.commonprefix
3145
3146smtplib -- support for sending very long messages
3147
3148socket -- new function getfqdn()
3149
3150readline -- new functions to read, write and truncate history files.
3151The readline section of the library reference manual contains an
3152example.
3153
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003154select -- add interface to poll system call
3155
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003156shutil -- new copyfileobj function
3157
3158SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3159HTTP server.
3160
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003161Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003162
3163urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003164e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003165
3166whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003167
3168
3169Obsolete Modules
3170----------------
3171
3172None. However note that 1.6 made a whole slew of modules obsolete:
3173stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3174poly, zmod, strop, util, whatsound.
3175
3176
3177Changed, New, Obsolete Tools
3178----------------------------
3179
Tim Peters8b092332000-09-05 20:15:25 +00003180None.
Guido van Rossume905e952000-09-05 12:42:46 +00003181
3182
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003183C-level Changes
3184---------------
3185
3186Several cleanup jobs were carried out throughout the source code.
3187
3188All C code was converted to ANSI C; we got rid of all uses of the
3189Py_PROTO() macro, which makes the header files a lot more readable.
3190
3191Most of the portability hacks were moved to a new header file,
3192pyport.h; several other new header files were added and some old
3193header files were removed, in an attempt to create a more rational set
3194of header files. (Few of these ever need to be included explicitly;
3195they are all included by Python.h.)
3196
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003197Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003198and Win64, especially for the new Intel Itanium processor. Mick also
3199added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003200
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003201The C APIs to return an object's size have been update to consistently
3202use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3203previous versions, the abstract interfaces used PyXXX_Length and the
3204concrete interfaces used PyXXX_Size. The old names,
3205e.g. PyObject_Length, are still available for backwards compatibility
3206at the API level, but are deprecated.
3207
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003208The PyOS_CheckStack function has been implemented on Windows by
3209Fredrik Lundh. It prevents Python from failing with a stack overflow
3210on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003211
3212The GC changes resulted in creation of two new slots on object,
3213tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003214the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003215
3216The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003217C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003218
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003219PyErr_Format has been updated to automatically calculate the size of
3220the buffer needed to hold the formatted result string. This change
3221prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003222
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003223New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003224
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003225PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3226that are the same as their non-Ex counterparts except they take an
3227extra flag argument that tells them to close the file when done.
3228
3229XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003230
Tim Peters8b092332000-09-05 20:15:25 +00003231
3232Windows Changes
3233---------------
3234
3235New popen2/popen3/peopen4 in os module (see Changed Modules above).
3236
3237os.popen is much more usable on Windows 95 and 98. See Microsoft
3238Knowledge Base article Q150956. The Win9x workaround described there
3239is implemented by the new w9xpopen.exe helper in the root of your
3240Python installation. Note that Python uses this internally; it is not
3241a standalone program.
3242
3243Administrator privileges are no longer required to install Python
3244on Windows NT or Windows 2000. If you have administrator privileges,
3245Python's registry info will be written under HKEY_LOCAL_MACHINE.
3246Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003247under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003248uses of Python, but will prevent some advanced uses from working
3249(for example, running a Python script as an NT service, or possibly
3250from CGI).
3251
3252[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3253installer; instead, it installs the needed Tcl/Tk files directly in the
3254Python directory. If you already have a Tcl/Tk installation, this
3255wastes some disk space (about 4 Megs) but avoids problems with
3256conflicting Tcl/Tk installations, and makes it much easier for Python
3257to ensure that Tcl/Tk can find all its files.
3258
3259[This was new in 1.6] The Windows installer now installs by default in
3260\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3261
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003262
3263Updates to the changes between 1.5.2 and 1.6
3264--------------------------------------------
3265
3266The 1.6 NEWS file can't be changed after the release is done, so here
3267is some late-breaking news:
3268
3269New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3270and changes to getlocale() and setlocale().
3271
3272The new module is now enabled per default.
3273
3274It is not true that the encodings codecs cannot be used for normal
3275strings: the string.encode() (which is also present on 8-bit strings
3276!) allows using them for 8-bit strings too, e.g. to convert files from
3277cp1252 (Windows) to latin-1 or vice-versa.
3278
3279Japanese codecs are available from Tamito KAJIYAMA:
3280http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3281
3282
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003283======================================================================