blob: 58d5a66e21d94b307a45d963362fe4cdadd647e4 [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
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +00009- PyErr_Display will provide file and line information for all exceptions
10 that have an attribute print_file_and_line, not just SyntaxErrors.
11
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000012- The UTF-8 codec will now encode and decode Unicode surrogates
13 correctly and without raising exceptions for unpaired ones.
14
Neal Norwitz649b7592002-01-01 19:07:13 +000015- file.xreadlines() now raises a ValueError if the file is closed:
16 Previously, an xreadlines object was returned which would raise
17 a ValueError when the xreadlines.next() method was called.
18
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000019- posix.killpg has been added where available.
20
Tim Petersaf8446f2001-12-21 21:36:50 +000021Extension modules
22
Martin v. Löwis29001ff2002-03-01 10:47:37 +000023- pwd and grp return enhanced tuples now, with symbolic field names.
24
Martin v. Löwis99866332002-03-01 10:27:01 +000025- array.array is now a type object. A new format character
26 'u' indicates Py_UNICODE arrays. For those, .tounicode and
27 .fromunicode methods are available. Arrays now support __iadd__
28 and __imul__.
29
Neal Norwitze790eae2002-01-01 21:14:12 +000030- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000031 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
32 is called.
33
Tim Petersaf8446f2001-12-21 21:36:50 +000034Library
35
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000036- socket module: the SSL support was broken out of the main
37 _socket module C helper and placed into a new _ssl helper
38 which now gets imported by socket.py if available and working.
39
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000040- encodings package: added aliases for all supported IANA character
41 sets
42
Guido van Rossum606fe4e2001-12-28 20:57:14 +000043- ftplib: to safeguard the user's privacy, anonymous login will use
44 "anonymous@" as default password, rather than the real user and host
45 name.
46
Fred Drake36736122002-01-10 13:50:31 +000047- webbrowser: tightened up the command passed to os.system() so that
48 arbitrary shell code can't be executed because a bogus URL was
49 passed in.
50
Tim Peters11bd9942002-02-01 00:52:29 +000051- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000052 gettext.find an optional all argument. Translations will now fallback
53 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000054
Martin v. Löwis9668b932002-01-12 11:27:42 +000055- distutils bdist commands now offer a --skip-build option.
56
Tim Petersaf8446f2001-12-21 21:36:50 +000057Tools/Demos
58
59Build
60
61C API
62
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000063- The "u#" parser marker will now pass through Unicode object as-is
64 without going through the buffer API.
65
Martin v. Löwis7198a522002-01-01 19:59:11 +000066- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
67
Tim Peters10a3bb52001-12-25 19:07:38 +000068- An old #define of ANY as void has been removed from pyport.h. This
69 hasn't been used since Python's pre-ANSI days, and the #define has
70 been marked as obsolete since then. SF bug 495548 says it created
71 conflicts with other packages, so keeping it around wasn't harmless.
72
Tim Petersaf8446f2001-12-21 21:36:50 +000073- Because Python's magic number scheme broke on January 1st, we decided
74 to stop Python development. Thanks for all the fish!
75
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000076- Some of us don't like fish, so we changed Python's magic number
77 scheme to a new one. See Python/import.c for details.
78
Tim Petersaf8446f2001-12-21 21:36:50 +000079New platforms
80
Martin v. Löwisa6e97582002-01-01 18:41:33 +000081- GNU/Hurd is now supported.
82
Tim Petersaf8446f2001-12-21 21:36:50 +000083Tests
84
85Windows
86
Tim Petersab034fa2002-02-01 11:27:43 +000087- os.waitpid() is now implemented for Windows, and can be used to block
88 until a specified process exits. This is similar to, but not exactly
89 the same as, os.waitpid() on POSIX systems. If you're waiting for
90 a specific process whose pid was obtained from one of the spawn()
91 functions, the same Python os.waitpid() code works across platforms.
92 See the docs for details.
93
Tim Peters11bd9942002-02-01 00:52:29 +000094- New tempfile.TemporaryFile implementation for Windows: this doesn't
95 need a TemproraryFileWrapper wrapper anymore, and should be immune
96 to a nasty problem: before 2.3, if you got a temp file on Windows, it
97 got wrapped in an object whose close() method first closed the
98 underlying file, then deleted the file. This usually worked fine.
99 However, the spawn family of functions on Windows create (at a low C
100 level) the same set of open files in the spawned process Q as were
101 open in the spawning process P. If a temp file f was among them, then
102 doing f.close() in P first closed P's C-level file handle on f, but Q's
103 C-level file handle on f remained open, so the attempt in P to delete f
104 blew up with a "Permission denied" error (Windows doesn't allow
105 deleting open files). This was surprising, subtle, and difficult to
106 work around.
107
108- The os module now exports all the symbolic constants usable with the
109 low-level os.open() on Windows: the new constants in 2.3 are
110 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
111 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
112 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
113 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
114 (so specify both if you want both; note that neither is useful unless
115 specified with O_CREAT too).
116
Tim Petersaf8446f2001-12-21 21:36:50 +0000117Mac
118
119
Tim Peters909c0912001-12-14 23:16:18 +0000120What's New in Python 2.2 final?
121Release date: 21-Dec-2001
122===============================
123
124Type/class unification and new-style classes
125
Barry Warsaw52acb492001-12-21 20:04:22 +0000126- pickle.py, cPickle: allow pickling instances of new-style classes
127 with a custom metaclass.
128
Tim Peters909c0912001-12-14 23:16:18 +0000129Core and builtins
130
Barry Warsaw52acb492001-12-21 20:04:22 +0000131- weakref proxy object: when comparing, unwrap both arguments if both
132 are proxies.
133
Tim Peters909c0912001-12-14 23:16:18 +0000134Extension modules
135
Barry Warsaw52acb492001-12-21 20:04:22 +0000136- binascii.b2a_base64(): fix a potential buffer overrun when encoding
137 very short strings.
138
139- cPickle: the obscure "fast" mode was suspected of causing stack
140 overflows on the Mac. Hopefully fixed this by setting the recursion
141 limit much smaller. If the limit is too low (it only affects
142 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
143 when compiling cPickle.c (or in pyconfig.h).
144
Tim Peters909c0912001-12-14 23:16:18 +0000145Library
146
Barry Warsaw52acb492001-12-21 20:04:22 +0000147- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
148 close or delete time).
149
150- rfc822.py: fixed a bug where the address '<>' was converted to None
151 instead of an empty string (also fixes the email.Utils module).
152
153- xmlrpclib.py: version 1.0.0; uses precision for doubles.
154
155- test suite: the pickle and cPickle tests were not executing any code
156 when run from the standard regresssion test.
157
Tim Peters909c0912001-12-14 23:16:18 +0000158Tools/Demos
159
160Build
161
162C API
163
164New platforms
165
166Tests
167
168Windows
169
Barry Warsaw52acb492001-12-21 20:04:22 +0000170- distutils package: fixed broken Windows installers (bdist_wininst).
171
172- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
173 instances are deleted at process exit time.
174
175- socket.py: prevent mysterious warnings when socket instances are
176 deleted at process exit time.
177
178- posixmodule.c: fix a Windows crash with stat() of a filename ending
179 in backslash.
180
Tim Peters909c0912001-12-14 23:16:18 +0000181Mac
182
Barry Warsaw52acb492001-12-21 20:04:22 +0000183- The Carbon toolbox modules have been upgraded to Universal Headers
184 3.4, and experimental CoreGraphics and CarbonEvents modules have
185 been added. All only for framework-enabled MacOSX.
186
Tim Peters909c0912001-12-14 23:16:18 +0000187
Tim Peters6272dfd2001-12-13 19:34:00 +0000188What's New in Python 2.2c1?
189Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000190===========================
191
192Type/class unification and new-style classes
193
Barry Warsaw06557452001-12-14 20:47:12 +0000194- Guido's tutorial introduction to the new type/class features has
195 been extensively updated. See
196
197 http://www.python.org/2.2/descrintro.html
198
199 That remains the primary documentation in this area.
200
Guido van Rossum33bab012001-12-05 22:45:48 +0000201- Fixed a leak: instance variables declared with __slots__ were never
202 deleted!
203
Guido van Rossum4b800852001-12-03 00:54:52 +0000204- The "delete attribute" method of descriptor objects is called
205 __delete__, not __del__. In previous releases, it was mistakenly
206 called __del__, which created an unfortunate overloading condition
207 with finalizers. (The "get attribute" and "set attribute" methods
208 are still called __get__ and __set__, respectively.)
209
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000210- Some subtle issues with the super built-in were fixed:
211
212 (a) When super itself is subclassed, its __get__ method would still
213 return an instance of the base class (i.e., of super).
214
215 (b) super(C, C()).__class__ would return C rather than super. This
216 is confusing. To fix this, I decided to change the semantics of
217 super so that it only applies to code attributes, not to data
218 attributes. After all, overriding data attributes is not
219 supported anyway.
220
221 (c) The __get__ method didn't check whether the argument was an
222 instance of the type used in creation of the super instance.
223
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000224- Previously, hash() of an instance of a subclass of a mutable type
225 (list or dictionary) would return some value, rather than raising
226 TypeError. This has been fixed. Also, directly calling
227 dict.__hash__ and list.__hash__ now raises the same TypeError
228 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000229
Guido van Rossumd331cb52001-12-05 19:46:42 +0000230- New-style objects now support deleting their __dict__. This is for
231 all intents and purposes equivalent to assigning a brand new empty
232 dictionary, but saves space if the object is not used further.
233
Tim Petersb3c9af12001-11-17 00:21:57 +0000234Core and builtins
235
Tim Peters3caca232001-12-06 06:23:26 +0000236- -Qnew now works as documented in PEP 238: when -Qnew is passed on
237 the command line, all occurrences of "/" use true division instead
238 of classic division. See the PEP for details. Note that "all"
239 means all instances in library and 3rd-party modules, as well as in
240 your own code. As the PEP says, -Qnew is intended for use only in
241 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000242 Note that test_coercion.py in the standard Python test suite fails
243 under -Qnew; this is expected, and won't be repaired until true
244 division becomes the default (in the meantime, test_coercion is
245 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000246
Fred Drake6c01e252001-12-14 17:08:12 +0000247- complex() now only allows the first argument to be a string
248 argument, and raises TypeError if either the second arg is a string
249 or if the second arg is specified when the first is a string.
250
Tim Petersb3c9af12001-11-17 00:21:57 +0000251Extension modules
252
Martin v. Löwis560da622001-11-24 09:24:51 +0000253- gc.get_referents was renamed to gc.get_referrers.
254
Tim Petersb3c9af12001-11-17 00:21:57 +0000255Library
256
Tim Peters25059d32001-12-07 20:35:43 +0000257- Functions in the os.spawn() family now release the global interpreter
258 lock around calling the platform spawn. They should always have done
259 this, but did not before 2.2c1. Multithreaded programs calling
260 an os.spawn function with P_WAIT will no longer block all Python threads
261 until the spawned program completes. It's possible that some programs
262 relies on blocking, although more likely by accident than by design.
263
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000264- webbrowser defaults to netscape.exe on OS/2 now.
265
Martin v. Löwis652e1912001-11-25 14:50:56 +0000266- Tix.ResizeHandle exposes detach_widget, hide, and show.
267
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000268- The charset alias windows_1252 has been added.
269
Barry Warsaw06557452001-12-14 20:47:12 +0000270- types.StringTypes is a tuple containing the defined string types;
271 usually this will be (str, unicode), but if Python was compiled
272 without Unicode support it will be just (str,).
273
274- The pulldom and minidom modules were synchronized to PyXML.
275
Tim Petersb3c9af12001-11-17 00:21:57 +0000276Tools/Demos
277
Barry Warsaw06557452001-12-14 20:47:12 +0000278- A new script called Tools/scripts/google.py was added, which fires
279 off a search on Google.
280
Tim Petersb3c9af12001-11-17 00:21:57 +0000281Build
282
Barry Warsaw06557452001-12-14 20:47:12 +0000283- Note that release builds of Python should arrange to define the
284 preprocessor symbol NDEBUG on the command line (or equivalent).
285 In the 2.2 pre-release series we tried to define this by magic in
286 Python.h instead, but it proved to cause problems for extension
287 authors. The Unix, Windows and Mac builds now all define NDEBUG in
288 release builds via cmdline (or equivalent) instead. Ports to
289 other platforms should do likewise.
290
Jack Jansen1999ef42001-12-06 21:47:20 +0000291- It is no longer necessary to use --with-suffix when building on a
292 case-insensitive file system (such as Mac OS X HFS+). In the build
293 directory an extension is used, but not in the installed python.
294
Tim Petersb3c9af12001-11-17 00:21:57 +0000295C API
296
Tim Petersf582b822001-12-11 18:51:08 +0000297- New function PyDict_MergeFromSeq2() exposes the builtin dict
298 constructor's logic for updating a dictionary from an iterable object
299 producing key-value pairs.
300
Tim Peterscffed4b2001-11-29 03:26:37 +0000301- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000302 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000303 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
304 dump core in some bad cases. This has been repaired. As a result,
305 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
306 previously went unchallenged.
307
Tim Petersb3c9af12001-11-17 00:21:57 +0000308New platforms
309
310Tests
311
312Windows
313
314Mac
315
Jack Jansenffa260f2001-12-06 21:14:00 +0000316- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
317 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000318
Barry Warsaw06557452001-12-14 20:47:12 +0000319- Changed logic for finding python home in Mac OS X framework Pythons.
320 Now sys.executable points to the executable again, in stead of to
321 the shared library. The latter is used only for locating the python
322 home.
323
324
Tim Peters84362bc2001-10-19 17:55:30 +0000325What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000326Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000327===========================
328
329Type/class unification and new-style classes
330
Guido van Rossum3d27df02001-11-15 20:27:54 +0000331- Multiple inheritance mixing new-style and classic classes in the
332 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000333
334 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000335 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000336
337 The MRO (method resolution order) for each base class is respected
338 according to its kind, but the MRO for the derived class is computed
339 using new-style MRO rules if any base clase is a new-style class.
340 This needs to be documented.
341
Tim Petersa427a2b2001-10-29 22:25:45 +0000342- The new builtin dictionary() constructor, and dictionary type, have
343 been renamed to dict. This reflects a decade of common usage.
344
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000345- dict() now accepts an iterable object producing 2-sequences. For
346 example, dict(d.items()) == d for any dictionary d. The argument,
347 and the elements of the argument, can be any iterable objects.
348
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000349- New-style classes can now have a __del__ method, which is called
350 when the instance is deleted (just like for classic classes).
351
Guido van Rossum12d955c2001-10-26 14:56:06 +0000352- Assignment to object.__dict__ is now possible, for objects that are
353 instances of new-style classes that have a __dict__ (unless the base
354 class forbids it).
355
Guido van Rossumc8e56452001-10-22 00:43:43 +0000356- Methods of built-in types now properly check for keyword arguments
357 (formerly these were silently ignored). The only built-in methods
358 that take keyword arguments are __call__, __init__ and __new__.
359
Guido van Rossum86443212001-10-27 22:28:54 +0000360- The socket function has been converted to a type; see below.
361
Tim Peters84362bc2001-10-19 17:55:30 +0000362Core and builtins
363
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000364- Assignment to __debug__ raises SyntaxError at compile-time. This
365 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000366 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000367
Guido van Rossum12d955c2001-10-26 14:56:06 +0000368- Clarified the error messages for unsupported operands to an operator
369 (like 1 + '').
370
Tim Peters84362bc2001-10-19 17:55:30 +0000371Extension modules
372
Tim Peters5ebfd362001-11-13 23:11:19 +0000373- mmap has a new keyword argument, "access", allowing a uniform way for
374 both Windows and Unix users to create read-only, write-through and
375 copy-on-write memory mappings. This was previously possible only on
376 Unix. A new keyword argument was required to support this in a
377 uniform way because the mmap() signuatures had diverged across
378 platforms. Thanks to Jay T Miller for repairing this!
379
Tim Peters169ded02001-11-03 19:57:21 +0000380- By default, the gc.garbage list now contains only those instances in
381 unreachable cycles that have __del__ methods; in 2.1 it contained all
382 instances in unreachable cycles. "Instances" here has been generalized
383 to include instances of both new-style and old-style classes.
384
Guido van Rossum12d955c2001-10-26 14:56:06 +0000385- The socket module defines a new method for socket objects,
386 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000387 send() until all data has been sent. Also, the socket function has
388 been converted to a subclassable type, like list and tuple (etc.)
389 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000390
391- Various bugfixes to the curses module. There is now a test suite
392 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000393
Guido van Rossum692adf12001-10-30 03:03:03 +0000394- binascii.b2a_base64 no longer places an arbitrary restriction of 57
395 bytes on its input.
396
Tim Peters84362bc2001-10-19 17:55:30 +0000397Library
398
Tim Peters5ebfd362001-11-13 23:11:19 +0000399- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000400 convenience function.
401
Tim Peters75335872001-11-03 19:35:43 +0000402- Symbolic group names in regular expressions must be unique. For
403 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
404 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000405 Python 2.2 detects this error at regexp compilation time;
406 previously, the error went undetected, and results were
407 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
408 pattern.subn() methods have been rewritten in C. Also, an
409 experimental function/method finditer() has been added, which works
410 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000411
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000412- Tix exposes more commands through the classes DirSelectBox,
413 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
414 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
415 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
416
Tim Peters98791af2001-10-23 01:59:54 +0000417- Traceback objects are now scanned by cyclic garbage collection, so
418 cycles created by casual use of sys.exc_info() no longer cause
419 permanent memory leaks (provided garbage collection is enabled).
420
Guido van Rossum49192142001-10-24 20:51:44 +0000421- os.extsep -- a new variable needed by the RISCOS support. It is the
422 separator used by extensions, and is '.' on all platforms except
423 RISCOS, where it is '/'. There is no need to use this variable
424 unless you have a masochistic desire to port your code to RISCOS.
425
Barry Warsaw012852b2001-11-16 16:17:27 +0000426- mimetypes.py has optional support for non-standard, but commonly
427 found types. guess_type() and guess_extension() now accept an
428 optional `strict' flag, defaulting to true, which controls whether
429 recognize non-standard types or not. A few non-standard types we
430 know about have been added. Also, when run as a script, there are
431 new -l and -e options.
432
433- statcache is now deprecated.
434
435- email.Utils.formatdate() now produces the preferred RFC 2822 style
436 dates with numeric timezones (it used to produce obsolete dates
437 hard coded to "GMT" timezone). An optional `localtime' flag is
438 added to produce dates in the local timezone, with daylight savings
439 time properly taken into account.
440
441- In pickle and cPickle, instead of masking errors in load() by
442 transforming them into SystemError, we let the original exception
443 propagate out. Also, implement support for __safe_for_unpickling__
444 in pickle, as it already was supported in cPickle.
445
Tim Peters84362bc2001-10-19 17:55:30 +0000446Tools/Demos
447
448Build
449
Barry Warsaw012852b2001-11-16 16:17:27 +0000450- The dbm module is built using libdb1 if available. The bsddb module
451 is built with libdb3 if available.
452
453- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
454
Tim Peters84362bc2001-10-19 17:55:30 +0000455C API
456
Tim Peters1fc240e2001-10-26 05:06:50 +0000457- New function PySequence_Fast_GET_SIZE() returns the size of a non-
458 NULL result from PySequence_Fast(), more quickly than calling
459 PySequence_Size().
460
Barry Warsaw012852b2001-11-16 16:17:27 +0000461- New argument unpacking function PyArg_UnpackTuple() added.
462
463- New functions PyObject_CallFunctionObjArgs() and
464 PyObject_CallMethodObjArgs() have been added to make it more
465 convenient and efficient to call functions and methods from C.
466
467- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
468 possible that this will propagate errors it didn't before.
469
470- New function PyObject_CheckReadBuffer(), which returns true if its
471 argument supports the single-segment readable buffer interface.
472
Tim Peters84362bc2001-10-19 17:55:30 +0000473New platforms
474
Guido van Rossum86443212001-10-27 22:28:54 +0000475- We've finally confirmed that this release builds on HP-UX 11.00,
476 *with* threads, and passes the test suite.
477
Tim Peters7a33d8b2001-11-05 02:51:07 +0000478- Thanks to a series of patches from Michael Muller, Python may build
479 again under OS/2 Visual Age C++.
480
Guido van Rossum49192142001-10-24 20:51:44 +0000481- Updated RISCOS port by Dietmar Schwertberger.
482
Tim Peters84362bc2001-10-19 17:55:30 +0000483Tests
484
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000485- Added a test script for the curses module. It isn't run automatically;
486 regrtest.py must be run with '-u curses' to enable it.
487
Tim Peters84362bc2001-10-19 17:55:30 +0000488Windows
489
Barry Warsaw012852b2001-11-16 16:17:27 +0000490Mac
491
492- PythonScript has been moved to unsupported and is slated to be
493 removed completely in the next release.
494
495- It should now be possible to build applets that work on both OS9 and
496 OSX.
497
498- The core is now linked with CoreServices not Carbon; as a side
499 result, default 8bit encoding on OSX is now ASCII.
500
501- Python should now build on OSX 10.1.1
502
Tim Peters84362bc2001-10-19 17:55:30 +0000503
Tim Petersabf925f2001-09-28 21:53:42 +0000504What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000505Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000506===========================
507
508Type/class unification and new-style classes
509
Guido van Rossum687ae002001-10-15 22:03:32 +0000510- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000511 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000512 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000513 remains: the __dict__ of a new-style class is a read-only proxy; you
514 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000515 __defined__ attribute of new-style types no longer exists, for lack
516 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000517 future a __cache__ may be resurrected with a similar function, if I
518 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000519
Tim Peters1c9ca872001-10-04 06:43:12 +0000520- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
521 always returned None, even when there was a class docstring).
522
523- doctest now finds and runs docstrings attached to new-style classes,
524 class methods, static methods, and properties.
525
Guido van Rossum9074ef62001-10-16 21:34:49 +0000526Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000527
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000528- A very subtle syntactical pitfall in list comprehensions was fixed.
529 For example: [a+b for a in 'abc', for b in 'def']. The comma in
530 this example is a mistake. Previously, this would silently let 'a'
531 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
532 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
533 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
534 Note that [a for a in <singleton>] is a convoluted way to say
535 [<singleton>] anyway, so it's not like any expressiveness is lost.
536
Guido van Rossum9074ef62001-10-16 21:34:49 +0000537- getattr(obj, name, default) now only catches AttributeError, as
538 documented, rather than returning the default value for all
539 exceptions (which could mask bugs in a __getattr__ hook, for
540 example).
541
Fred Drakecb7a6b52001-10-22 18:41:51 +0000542- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000543 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000544 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000545 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000546
Guido van Rossum1c486092001-10-19 02:05:35 +0000547- unicode(obj) now behaves more like str(obj), accepting arbitrary
548 objects, and calling a __unicode__ method if it exists.
549 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000550 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000551
Barry Warsawf6fb1712001-10-19 05:35:40 +0000552- isinstance() now allows any object as the first argument and a
553 class, a type or something with a __bases__ tuple attribute for the
554 second argument. The second argument may also be a tuple of a
555 class, type, or something with __bases__, in which case isinstance()
556 will return true if the first argument is an instance of any of the
557 things contained in the second argument tuple. E.g.
558
559 isinstance(x, (A, B))
560
561 returns true if x is an instance of A or B.
562
Guido van Rossum9074ef62001-10-16 21:34:49 +0000563Extension modules
564
565- thread.start_new_thread() now returns the thread ID (previously None).
566
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000567- binascii has now two quopri support functions, a2b_qp and b2a_qp.
568
Guido van Rossumc524d952001-10-19 01:31:59 +0000569- readline now supports setting the startup_hook and the
570 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000571
Guido van Rossumc524d952001-10-19 01:31:59 +0000572- os and posix supports chroot(), setgroups() and unsetenv() where
573 available. The stat(), fstat(), statvfs() and fstatvfs() functions
574 now return "pseudo-sequences" -- the various fields can now be
575 accessed as attributes (e.g. os.stat("/").st_mtime) but for
576 backwards compatibility they also behave as a fixed-length sequence.
577 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000578 attributes.
579
580- time: localtime(), gmtime() and strptime() now return a
581 pseudo-sequence similar to the os.stat() return value, with
582 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000583
Guido van Rossum9074ef62001-10-16 21:34:49 +0000584- Decompression objects in the zlib module now accept an optional
585 second parameter to decompress() that specifies the maximum amount
586 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000587
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000588- optional SSL support in the socket module now exports OpenSSL
589 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
590 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000591 automatically seed its PRNG. Also, the keyfile and certfile
592 arguments to socket.ssl() are now optional.
593
594- posixmodule (and by extension, the os module on POSIX platforms) now
595 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000596
Guido van Rossum9074ef62001-10-16 21:34:49 +0000597Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000598
Tim Peters7402f792001-10-02 03:53:41 +0000599- doctest now excludes functions and classes not defined by the module
600 being tested, thanks to Tim Hochberg.
601
Fred Drakecb7a6b52001-10-22 18:41:51 +0000602- HotShot, a new profiler implemented using a C-based callback, has
603 been added. This substantially reduces the overhead of profiling,
604 but it is still quite preliminary. Support modules and
605 documentation will be added in upcoming releases (before 2.2 final).
606
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000607- profile now produces correct output in situations where an exception
608 raised in Python is cleared by C code (e.g. hasattr()). This used
609 to cause wrong output, including spurious claims of recursive
610 functions and attribution of time spent to the wrong function.
611
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000612 The code and documentation for the derived OldProfile and HotProfile
613 profiling classes was removed. The code hasn't worked for years (if
614 you tried to use them, they raised exceptions). OldProfile
615 intended to reproduce the behavior of the profiler Python used more
616 than 7 years ago, and isn't interesting anymore. HotProfile intended
617 to provide a faster profiler (but producing less information), and
618 that's a worthy goal we intend to meet via a different approach (but
619 without losing information).
620
Tim Peterscce092d2001-10-09 05:31:56 +0000621- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000622 a much better system-specific calibration constant. The constant can
623 now be specified in an instance constructor, or as a Profile class or
624 instance variable, instead of by editing profile.py's source code.
625 Calibration must still be done manually (see the docs for the profile
626 module).
627
628 Note that Profile.calibrate() must be overriden by subclasses.
629 Improving the accuracy required exploiting detailed knowledge of
630 profiler internals; the earlier method abstracted away the details
631 and measured a simplified model instead, but consequently computed
632 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000633
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000634- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000635 which indicates whether output is intended for the header 'Q'
636 encoding.
637
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000638- The SocketServer.ThreadingMixIn class now closes the request after
639 finish_request() returns. (Not when it errors out though.)
640
Barry Warsawf6fb1712001-10-19 05:35:40 +0000641- The nntplib module's NNTP.body() method has grown a `file' argument
642 to allow saving the message body to a file.
643
644- The email package has added a class email.Parser.HeaderParser which
645 only parses headers and does not recurse into the message's body.
646 Also, the module/class MIMEAudio has been added for representing
647 audio data (contributed by Anthony Baxter).
648
649- ftplib should be able to handle files > 2GB.
650
651- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
652 ON, and OFF.
653
Fred Drakecb7a6b52001-10-22 18:41:51 +0000654- xml.dom.minidom NodeList objects now support the length attribute
655 and item() method as required by the DOM specifications.
656
Guido van Rossumed554f62001-10-02 23:15:37 +0000657Tools/Demos
658
659- Demo/dns was removed. It no longer serves any purpose; a package
660 derived from it is now maintained by Anthony Baxter, see
661 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000662
Barry Warsawf6fb1712001-10-19 05:35:40 +0000663- The freeze tool has been made more robust, and two new options have
664 been added: -X and -E.
665
Tim Petersabf925f2001-09-28 21:53:42 +0000666Build
667
Barry Warsawf6fb1712001-10-19 05:35:40 +0000668- configure will use CXX in LINKCC if CXX is used to build main() and
669 the system requires to link a C++ main using the C++ compiler.
670
Tim Petersabf925f2001-09-28 21:53:42 +0000671C API
672
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000673- The documentation for the tp_compare slot is updated to require that
674 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
675 not correct. This is not yet enforced but will be enforced in
676 Python 2.3; even later, we may use -2 to indicate errors and +2 for
677 "NotImplemented". Right now, -1 should be used for an error return.
678
Tim Petersd38b1c72001-09-30 05:09:37 +0000679- PyLong_AsLongLong() now accepts int (as well as long) arguments.
680 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
681 as long) arguments.
682
Guido van Rossum3c288632001-10-16 21:13:49 +0000683- PyThread_start_new_thread() now returns a long int giving the thread
684 ID, if one can be calculated; it returns -1 for error, 0 if no
685 thread ID is calculated (this is an incompatible change, but only
686 the thread module used this API). This code has only really been
687 tested on Linux and Windows; other platforms please beware (and
688 report any bugs or strange behavior).
689
Guido van Rossum1c486092001-10-19 02:05:35 +0000690- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
691 input.
692
Tim Petersabf925f2001-09-28 21:53:42 +0000693New platforms
694
695Tests
696
697Windows
698
Tim Peters04cf1d32001-10-09 22:39:40 +0000699- Installer: If you install IDLE, and don't disable file-extension
700 registration, a new "Edit with IDLE" context (right-click) menu entry
701 is created for .py and .pyw files.
702
Tim Peters1ce3cf72001-10-01 17:58:40 +0000703- The signal module now supports SIGBREAK on Windows, thanks to Steven
704 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
705 action remains to call Win32 ExitProcess(). This can be changed via
706 signal.signal(). For example:
707
708 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
709 # (SIGINT) behavior.
710 import signal
711 signal.signal(signal.SIGBREAK,
712 signal.default_int_handler)
713
714 try:
715 while 1:
716 pass
717 except KeyboardInterrupt:
718 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
719 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
720 # program without the possibility for any Python-level cleanup).
721 print "Clean exit"
722
Tim Petersabf925f2001-09-28 21:53:42 +0000723
Tim Petersb07352e2001-09-08 01:25:47 +0000724What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000725Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000726===========================
727
Guido van Rossum808eea72001-09-25 04:15:41 +0000728Type/class unification and new-style classes
729
730- pydoc and inspect are now aware of new-style classes;
731 e.g. help(list) at the interactive prompt now shows proper
732 documentation for all operations on list objects.
733
734- Applications using Jim Fulton's ExtensionClass module can now safely
735 be used with Python 2.2. In particular, Zope 2.4.1 now works with
736 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
737 examples also work again. It is hoped that Gtk and Boost also work
738 with 2.2a4 and beyond. (If you can confirm this, please write
739 webmaster@python.org; if there are still problems, please open a bug
740 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000741
Tim Peters66c1a522001-09-24 21:17:50 +0000742- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
743 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
744 in the constructed property object. fget, fset and fdel weren't
745 discoverable from Python in 2.2a3. __doc__ is new, and allows to
746 associate a docstring with a property.
747
Guido van Rossum808eea72001-09-25 04:15:41 +0000748- Comparison overloading is now more completely implemented. For
749 example, a str subclass instance can properly be compared to a str
750 instance, and it can properly overload comparison. Ditto for most
751 other built-in object types.
752
753- The repr() of new-style classes has changed; instead of <type
754 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
755 *except* for built-in types, which are still rendered as <type
756 'Foo'> (to avoid upsetting existing code that might parse or
757 otherwise rely on repr() of certain type objects).
758
759- The repr() of new-style objects is now always <Foo object at XXX>;
760 previously, it was sometimes <Foo instance at XXX>.
761
762- For new-style classes, what was previously called __getattr__ is now
763 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000764 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000765 one in classic classes is defined which is called only if regular
766 attribute access raises AttributeError; to catch *all* attribute
767 access, you can use __getattribute__ (for new-style classes). If
768 both are defined, __getattribute__ is called first, and if it raises
769 AttributeError, __getattr__ is called.
770
771- The __class__ attribute of new-style objects can be assigned to.
772 The new class must have the same C-level object layout as the old
773 class.
774
775- The builtin file type can be subclassed now. In the usual pattern,
776 "file" is the name of the builtin type, and file() is a new builtin
777 constructor, with the same signature as the builtin open() function.
778 file() is now the preferred way to open a file.
779
780- Previously, __new__ would only see sequential arguments passed to
781 the type in a constructor call; __init__ would see both sequential
782 and keyword arguments. This made no sense whatsoever any more, so
783 now both __new__ and __init__ see all arguments.
784
785- Previously, hash() applied to an instance of a subclass of str or
786 unicode always returned 0. This has been repaired.
787
788- Previously, an operation on an instance of a subclass of an
789 immutable type (int, long, float, complex, tuple, str, unicode),
790 where the subtype didn't override the operation (and so the
791 operation was handled by the builtin type), could return that
792 instance instead a value of the base type. For example, if s was of
793 a str sublass type, s[:] returned s as-is. Now it returns a str
794 with the same value as s.
795
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000796- Provisional support for pickling new-style objects has been added.
797
Guido van Rossum808eea72001-09-25 04:15:41 +0000798Core
799
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000800- file.writelines() now accepts any iterable object producing strings.
801
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000802- PyUnicode_FromEncodedObject() now works very much like
803 PyObject_Str(obj) in that it tries to use __str__/tp_str
804 on the object if the object is not a string or buffer. This
805 makes unicode() behave like str() when applied to non-string/buffer
806 objects.
807
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000808- PyFile_WriteObject now passes Unicode objects to the file's write
809 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000810 of a print statement must support Unicode objects, i.e. they must
811 at least convert them into ASCII strings.
812
Guido van Rossum624c8af2001-09-18 15:21:04 +0000813- Thread scheduling on Solaris should be improved; it is no longer
814 necessary to insert a small sleep at the start of a thread in order
815 to let other runnable threads be scheduled.
816
Tim Petersb07352e2001-09-08 01:25:47 +0000817Library
818
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000819- StringIO.StringIO instances and cStringIO.StringIO instances support
820 read character buffer compatible objects for their .write() methods.
821 These objects are converted to strings and then handled as such
822 by the instances.
823
Barry Warsaw2f600732001-09-24 04:28:10 +0000824- The "email" package has been added. This is basically a port of the
825 mimelib package <http://sf.net/projects/mimelib> with API changes
826 and some implementations updated to use iterators and generators.
827
Tim Peters8a9c2842001-09-22 21:30:22 +0000828- difflib.ndiff() and difflib.Differ.compare() are generators now. This
829 restores the ability of Tools/scripts/ndiff.py to start producing output
830 before the entire comparison is complete.
831
Barry Warsaw58b072d2001-09-22 04:44:21 +0000832- StringIO.StringIO instances and cStringIO.StringIO instances support
833 iteration just like file objects (i.e. their .readline() method is
834 called for each iteration until it returns an empty string).
835
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000836- The codecs module has grown four new helper APIs to access
837 builtin codecs: getencoder(), getdecoder(), getreader(),
838 getwriter().
839
Guido van Rossum624c8af2001-09-18 15:21:04 +0000840- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
841 simplifies writing XML RPC servers.
842
Barry Warsaw647d5e82001-09-28 17:01:02 +0000843- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000844 after interpretation of symbolic links. On non-Unix systems, this
845 is an alias for os.path.abspath().
846
Tim Peters16a77ad2001-09-08 04:00:12 +0000847- operator.indexOf() (PySequence_Index() in the C API) now works with any
848 iterable object.
849
Guido van Rossum624c8af2001-09-18 15:21:04 +0000850- smtplib now supports various authentication and security features of
851 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000852
Guido van Rossum624c8af2001-09-18 15:21:04 +0000853- hmac: a new module implementing keyed hashing for message
854 authentication.
855
856- mimetypes now recognizes more extensions and file types. At the
857 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000858
Guido van Rossum624c8af2001-09-18 15:21:04 +0000859- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000860 Python 2.2 bytecode generation. It has also been promoted from a
861 Tool to a standard library package. (Tools/compiler still exists as
862 a sample driver.)
863
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000864Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000865
Tim Petersb07352e2001-09-08 01:25:47 +0000866Build
867
Guido van Rossum624c8af2001-09-18 15:21:04 +0000868- Large file support (LFS) is now automatic when the platform supports
869 it; no more manual configuration tweaks are needed. On Linux, at
870 least, it's possible to have a system whose C library supports large
871 files but whose kernel doesn't; in this case, large file support is
872 still enabled but doesn't do you any good unless you upgrade your
873 kernel or share your Python executable with another system whose
874 kernel has large file support.
875
876- The configure script now supplies plausible defaults in a
877 cross-compilation environment. This doesn't mean that the supplied
878 values are always correct, or that cross-compilation now works
879 flawlessly -- but it's a first step (and it shuts up most of
880 autoconf's warnings about AC_TRY_RUN).
881
882- The Unix build is now a bit less chatty, courtesy of the parser
883 generator. The build is completely silent (except for errors) when
884 using "make -s", thanks to a -q option to setup.py.
885
Tim Petersb07352e2001-09-08 01:25:47 +0000886C API
887
Guido van Rossum624c8af2001-09-18 15:21:04 +0000888- The "structmember" API now supports some new flag bits to deny read
889 and/or write access to attributes in restricted execution mode.
890
Tim Petersb07352e2001-09-08 01:25:47 +0000891New platforms
892
Guido van Rossum624c8af2001-09-18 15:21:04 +0000893- Compaq's iPAQ handheld, running the "familiar" Linux distribution
894 (http://familiar.handhelds.org).
895
Tim Petersb07352e2001-09-08 01:25:47 +0000896Tests
897
Tim Peters8a9c2842001-09-22 21:30:22 +0000898- The "classic" standard tests, which work by comparing stdout to
899 an expected-output file under Lib/test/output/, no longer stop at
900 the first mismatch. Instead the test is run to completion, and a
901 variant of ndiff-style comparison is used to report all differences.
902 This is much easier to understand than the previous style of reporting.
903
904- The unittest-based standard tests now use regrtest's test_main()
905 convention, instead of running as a side-effect of merely being
906 imported. This allows these tests to be run in more natural and
907 flexible ways as unittests, outside the regrtest framework.
908
909- regrtest.py is much better integrated with unittest and doctest now,
910 especially in regard to reporting errors.
911
Tim Petersb07352e2001-09-08 01:25:47 +0000912Windows
913
Guido van Rossum624c8af2001-09-18 15:21:04 +0000914- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000915 that support it (NTFS under Windows 2000). See "What's New in
916 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000917
Tim Petersb07352e2001-09-08 01:25:47 +0000918
Tim Petersedc99312001-08-22 21:36:50 +0000919What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000920Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000921===========================
922
923Core
924
Tim Peters9fffa3e2001-09-04 05:14:19 +0000925- Conversion of long to float now raises OverflowError if the long is too
926 big to represent as a C double.
927
Tim Peters32f453e2001-09-03 08:35:41 +0000928- The 3-argument builtin pow() no longer allows a third non-None argument
929 if either of the first two arguments is a float, or if both are of
930 integer types and the second argument is negative (in which latter case
931 the arguments are converted to float, so this is really the same
932 restriction).
933
Tim Peters5d2b77c2001-09-03 05:47:38 +0000934- The builtin dir() now returns more information, and sometimes much
935 more, generally naming all attributes of an object, and all attributes
936 reachable from the object via its class, and from its class's base
937 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
938 an empty list. In 2.2a3,
939
940 >>> dir([])
941 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
942 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
943 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
944 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
945 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
946 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
947 'reverse', 'sort']
948
949 dir(module) continues to return only the module's attributes, though.
950
Tim Petersbdee63f2001-09-02 03:40:59 +0000951- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000952 than raising OverflowError. This is a partial implementation of PEP
953 237. You can use -Wdefault::OverflowWarning to enable a warning for
954 this situation, and -Werror::OverflowWarning to revert to the old
955 OverflowError exception.
956
Guido van Rossum61c345f2001-09-04 03:26:15 +0000957- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000958 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000959 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
960 -Qold, meaning the / operator has its classic meaning and no
961 warnings are issued. Using -Qwarn issues a run-time warning about
962 all uses of classic division for int and long arguments; -Qwarnall
963 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000964 (for use with fixdiv.py).
965 [Note: the remainder of this paragraph (preserved below) became
966 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
967 <obsolete>
968 Using -Qnew is questionable; it turns on new division by default, but
969 only in the __main__ module. You can usefully combine -Qwarn or
970 -Qwarnall and -Qnew: this gives the __main__ module new division, and
971 warns about classic division everywhere else.
972 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000973
Tim Petersbdee63f2001-09-02 03:40:59 +0000974- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000975 long, float, str, unicode, and tuple. (The types complex, list and
976 dictionary can also be subclassed; this was introduced earlier.)
977 Note that restrictions apply when subclassing immutable built-in
978 types: you can only affect the value of the instance by overloading
979 __new__. You can add mutable attributes, and the subclass instances
980 will have a __dict__ attribute, but you cannot change the "value"
981 (as implemented by the base class) of an immutable subclass instance
982 once it is created.
983
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000984- The dictionary constructor now takes an optional argument, a
985 mapping-like object, and initializes the dictionary from its
986 (key, value) pairs.
987
Tim Petersbdee63f2001-09-02 03:40:59 +0000988- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000989 "cooperative super calls" in a multiple inheritance setting. For an
990 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
991
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000992- A new built-in type, property, has been added. This enables the
993 creation of "properties". These are attributes implemented by
994 getter and setter functions (or only one of these for read-only or
995 write-only attributes), without the need to override __getattr__.
996 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000997
Tim Petersbdee63f2001-09-02 03:40:59 +0000998- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000999 liberalized, to allow leading zeroes. Examples of literals now
1000 legal that were SyntaxErrors before:
1001
1002 00.0 0e3 0100j 07.5 00000000000000000008.
1003
Tim Petersbdee63f2001-09-02 03:40:59 +00001004- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001005 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1006
Tim Petersedc99312001-08-22 21:36:50 +00001007Library
1008
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001009- telnetlib includes symbolic names for the options, and support for
1010 setting an option negotiation callback.
1011
Tim Petersa40c7932001-09-05 22:36:56 +00001012- The new C standard no longer requires that math libraries set errno to
1013 ERANGE on overflow. For platform libraries that exploit this new
1014 freedom, Python's overflow-checking was wholly broken. A new overflow-
1015 checking scheme attempts to repair that, but may not be reliable on all
1016 platforms (C doesn't seem to provide anything both useful and portable
1017 in this area anymore).
1018
Martin v. Löwis44f86962001-09-05 13:44:54 +00001019- Asynchronous timeout actions are available through the new class
1020 threading.Timer.
1021
Tim Peters78526162001-09-05 00:53:45 +00001022- math.log and math.log10 now return sensible results for even huge
1023 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1024
Tim Petersbdee63f2001-09-02 03:40:59 +00001025- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001026 currently held. See the docs for the imp module.
1027
Tim Petersbdee63f2001-09-02 03:40:59 +00001028- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001029 dumps containing ints written on platforms where Python ints are 8 bytes.
1030 When read on a box where Python ints are 4 bytes, such values are
1031 converted to Python longs.
1032
Tim Petersbdee63f2001-09-02 03:40:59 +00001033- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001034 code objects is no longer allowed. This plugs a security hole.
1035
Steve Purcell6091cd62001-09-06 16:05:17 +00001036- unittest.TestResult instances no longer store references to tracebacks
1037 generated by test failures. This prevents unexpected dangling references
1038 to objects that should be garbage collected between tests.
1039
Tim Petersedc99312001-08-22 21:36:50 +00001040Tools
1041
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001042- Tools/scripts/fixdiv.py has been added which can be used to fix
1043 division operators as per PEP 238.
1044
Tim Petersedc99312001-08-22 21:36:50 +00001045Build
1046
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001047- If you are an adventurous person using Mac OS X you may want to look at
1048 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1049 application, which can be used for experimenting with Carbon or Cocoa.
1050 Discussion of this on pythonmac-sig, please.
1051
Tim Peters7eea37e2001-09-04 22:08:56 +00001052C API
1053
1054- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001055
Tim Peters9fffa3e2001-09-04 05:14:19 +00001056- Note that PyLong_AsDouble can fail! This has always been true, but no
1057 callers checked for it. It's more likely to fail now, because overflow
1058 errors are properly detected now. The proper way to check:
1059
1060 double x = PyLong_AsDouble(some_long_object);
1061 if (x == -1.0 && PyErr_Occurred()) {
1062 /* The conversion failed. */
1063 }
1064
Tim Petersbdee63f2001-09-02 03:40:59 +00001065- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001066 compile but will not participate in GC. To upgrade an extension
1067 module:
1068
1069 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001070
Neil Schemenauer4042c692001-08-30 15:38:01 +00001071 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1072 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001073
Neil Schemenauer4042c692001-08-30 15:38:01 +00001074 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1075 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001076
Neil Schemenauer4042c692001-08-30 15:38:01 +00001077 - remove PyGC_HEAD_SIZE from object size calculations
1078
1079 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1080
Tim Petersbdee63f2001-09-02 03:40:59 +00001081- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001082 These can be used safely to construct string objects from a
1083 sprintf-style format string (similar to the format string supported
1084 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001085
Tim Petersedc99312001-08-22 21:36:50 +00001086New platforms
1087
Tim Petersb7da0902001-09-02 23:01:43 +00001088- Stephen Hansen contributed patches sufficient to get a clean compile
1089 under Borland C (Windows), but he reports problems running it and ran
1090 out of time to complete the port. Volunteers? Expect a MemoryError
1091 when importing the types module; this is probably shallow, and
1092 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001093
Tim Petersedc99312001-08-22 21:36:50 +00001094Tests
1095
1096Windows
1097
Tim Peters6e13a562001-09-06 00:32:15 +00001098- Large file support is now enabled on Win32 platforms as well as on
1099 Win64. This means that, for example, you can use f.tell() and f.seek()
1100 to manipulate files larger than 2 gigabytes (provided you have enough
1101 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001102 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1103 filesize limit, and large file support makes no difference there.
1104 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1105 NTFS has no practical limit on file size, and files of any size can be
1106 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001107
Tim Petersbdee63f2001-09-02 03:40:59 +00001108- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001109 points to command.com (patch from Brian Quinlan).
1110
Tim Petersedc99312001-08-22 21:36:50 +00001111
Tim Peters20f51a72001-07-21 02:31:40 +00001112What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001113Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001114===========================
1115
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001116Build
1117
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001118- Tim Peters developed a brand new Windows installer using Wise 8.1,
1119 generously donated to us by Wise Solutions.
1120
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001121- configure supports a new option --enable-unicode, with the values
1122 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1123 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001124
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001125- A new configure option --enable-framework builds a Mac OS X framework,
1126 which "make frameworkinstall" will install. This provides a starting
1127 point for more mac-like functionality, join pythonmac-sig@python.org
1128 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001129
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001130- The NeXT platform is no longer supported.
1131
1132- The `new' module is now statically linked.
1133
Tim Peters0afb6092001-08-15 06:06:44 +00001134Tools
1135
1136- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001137 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001138 the module docstring for details.
1139
Tim Peters20f51a72001-07-21 02:31:40 +00001140Tests
1141
Tim Peters5e824c32001-08-12 22:25:01 +00001142- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001143 platforms, allowing to give clearer test result output. regrtest
1144 also has optional --use/-u switch to run normally disabled tests
1145 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001146
Tim Peters20f51a72001-07-21 02:31:40 +00001147- Several new tests in the standard test suite, with special thanks to
1148 Nick Mathewson.
1149
1150Core
1151
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001152- The floor division operator // has been added as outlined in PEP
1153 238. The / operator still provides classic division (and will until
1154 Python 3.0) unless "from __future__ import division" is included, in
1155 which case the / operator will provide true division. The operator
1156 module provides truediv() and floordiv() functions. Augmented
1157 assignment variants are included, as are the equivalent overloadable
1158 methods and C API methods. See the PEP for a full discussion:
1159 <http://python.sf.net/peps/pep-0238.html>
1160
Tim Peters6cd6a822001-08-17 22:11:27 +00001161- Future statements are now effective in simulated interactive shells
1162 (like IDLE). This should "just work" by magic, but read Michael
1163 Hudson's "Future statements in simulated shells" PEP 264 for full
1164 details: <http://python.sf.net/peps/pep-0264.html>.
1165
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001166- The type/class unification (PEP 252-253) was integrated into the
1167 trunk and is not so tentative any more (the exact specification of
1168 some features is still tentative). A lot of work has done on fixing
1169 bugs and adding robustness and features (performance still has to
1170 come a long way).
1171
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001172- Warnings about a mismatch in the Python API during extension import
1173 now use the Python warning framework (which makes it possible to
1174 write filters for these warnings).
1175
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001176- A function's __dict__ (aka func_dict) will now always be a
1177 dictionary. It used to be possible to delete it or set it to None,
1178 but now both actions raise TypeErrors. It is still legal to set it
1179 to a dictionary object. Getting func.__dict__ before any attributes
1180 have been assigned now returns an empty dictionary instead of None.
1181
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001182- A new command line option, -E, was added which disables the use of
1183 all environment variables, or at least those that are specifically
1184 significant to Python. Usually those have a name starting with
1185 "PYTHON". This was used to fix a problem where the tests fail if
1186 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1187 older distribution.
1188
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001189Library
1190
Tim Peters5e824c32001-08-12 22:25:01 +00001191- New class Differ and new functions ndiff() and restore() in difflib.py.
1192 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001193 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001194
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001195- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1196 value using the minimal quoting required for the value; more
1197 reliable than using xml.sax.saxutils.escape() for attribute values.
1198
1199- Readline completion support for cmd.Cmd was added.
1200
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001201- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1202
1203- Added function threading.BoundedSemaphore()
1204
1205- Added Ka-Ping Yee's cgitb.py module.
1206
1207- The `new' module now exposes the CO_xxx flags.
1208
Martin v. Löwis560da622001-11-24 09:24:51 +00001209- The gc module offers the get_referents function.
1210
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001211New platforms
1212
1213C API
1214
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001215- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1216 which provide a cross-platform implementations for the
1217 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1218 the standard sprintf() and vsprintf() C lib APIs, these versions
1219 apply bounds checking on the used buffer which enhances protection
1220 against buffer overruns.
1221
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001222- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001223 and extensions using different Unicode widths is rendered next to
1224 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001225 will result in an ImportError. Unicode extensions writers must make
1226 sure to check the Unicode width compatibility in their extensions by
1227 using at least one of the mangled Unicode APIs in the extension.
1228
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001229- Two new flags METH_NOARGS and METH_O are available in method definition
1230 tables to simplify implementation of methods with no arguments and a
1231 single untyped argument. Calling such methods is more efficient than
1232 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1233 deprecated.
1234
Tim Petersc1731372001-08-04 08:12:36 +00001235Windows
1236
1237- "import module" now compiles module.pyw if it exists and nothing else
1238 relevant is found.
1239
Tim Peters20f51a72001-07-21 02:31:40 +00001240
Guido van Rossum55a78992001-07-17 17:22:32 +00001241What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001242Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001243===========================
1244
1245Core
Tim Petersa814db52001-05-14 07:05:58 +00001246
Tim Peters6d6c1a32001-08-02 04:15:00 +00001247- TENTATIVELY, a large amount of code implementing much of what's
1248 described in PEP 252 (Making Types Look More Like Classes) and PEP
1249 253 (Subtyping Built-in Types) was added. This will be released
1250 with Python 2.2a1. Documentation will be provided separately
1251 through http://www.python.org/2.2/. The purpose of releasing this
1252 with Python 2.2a1 is to test backwards compatibility. It is
1253 possible, though not likely, that a decision is made not to release
1254 this code as part of 2.2 final, if any serious backwards
1255 incompapatibilities are found during alpha testing that cannot be
1256 repaired.
1257
Guido van Rossum55a78992001-07-17 17:22:32 +00001258- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001259 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001260 more 'yield' statements. See PEP 255. Since this adds a new
1261 keyword to the language, this feature must be enabled by including a
1262 future statement: "from __future__ import generators" (see PEP 236).
1263 Generators will become a standard feature in a future release
1264 (probably 2.3). Without this future statement, 'yield' remains an
1265 ordinary identifier, but a warning is issued each time it is used.
1266 (These warnings currently don't conform to the warnings framework of
1267 PEP 230; we intend to fix this in 2.2a2.)
1268
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001269- The UTF-16 codec was modified to be more RFC compliant. It will now
1270 only remove BOM characters at the start of the string and then
1271 only if running in native mode (UTF-16-LE and -BE won't remove a
1272 leading BMO character).
1273
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001274- Strings now have a new method .decode() to complement the already
1275 existing .encode() method. These two methods provide direct access
1276 to the corresponding decoders and encoders of the registered codecs.
1277
1278 To enhance the usability of the .encode() method, the special
1279 casing of Unicode object return values was dropped (Unicode objects
1280 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001281
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001282 Both methods will now return whatever the codec in charge of the
1283 requested encoding returns as object, e.g. Unicode codecs will
1284 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1285 will return u"äöü"). This enables codec writer to create codecs
1286 for various simple to use conversions.
1287
1288 New codecs were added to demonstrate these new features (the .encode()
1289 and .decode() columns indicate the type of the returned objects):
1290
1291 Name | .encode() | .decode() | Description
1292 ----------------------------------------------------------------------
1293 uu | string | string | UU codec (e.g. for email)
1294 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001295 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001296 zlib | string | string | zlib compression
1297 hex | string | string | 2-byte hex codec
1298 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1299
Mark Hammond2a0af792001-05-14 03:09:36 +00001300- Some operating systems now support the concept of a default Unicode
1301 encoding for file system operations. Notably, Windows supports 'mbcs'
1302 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001303 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001304 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001305
1306 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001307 functions that return filenames (such as os.listdir()) to return Python
1308 string objects pre-encoded using the default file system encoding for
1309 the platform. As this encoding is likely to be different from Python's
1310 default encoding, converting this name to a Unicode object before passing
1311 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001312 would attempt to use its default encoding (generally ASCII) rather than
1313 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001314
Tim Petersa814db52001-05-14 07:05:58 +00001315 In general, this change simply removes surprises when working with
1316 Unicode and the file system, making these operations work as you expect,
1317 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001318 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001319
Tim Peters61dff2b2001-05-08 15:43:37 +00001320- Float (and complex) literals in source code were evaluated to full
1321 precision only when running from a .py file; the same code loaded from a
1322 .pyc (or .pyo) file could suffer numeric differences starting at about the
1323 12th significant decimal digit. For example, on a machine with IEEE-754
1324 floating arithmetic,
1325
1326 x = 9007199254740992.0
1327 print long(x)
1328
1329 printed 9007199254740992 if run directly from .py, but 9007199254740000
1330 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1331 str(float) instead of repr(float) when building code objects. marshal
1332 now uses repr(float) instead, which should reproduce floats to full
1333 machine precision (assuming the platform C float<->string I/O conversion
1334 functions are of good quality).
1335
1336 This may cause floating-point results to change in some cases, and
1337 usually for the better, but may also cause numerically unstable
1338 algorithms to break.
1339
Tim Peters2f228e72001-05-13 00:19:31 +00001340- The implementation of dicts suffers fewer collisions, which has speed
1341 benefits. However, the order in which dict entries appear in dict.keys(),
1342 dict.values() and dict.items() may differ from previous releases for a
1343 given dict. Nothing is defined about this order, so no program should
1344 rely on it. Nevertheless, it's easy to write test cases that rely on the
1345 order by accident, typically because of printing the str() or repr() of a
1346 dict to an "expected results" file. See Lib/test/test_support.py's new
1347 sortdict(dict) function for a simple way to display a dict in sorted
1348 order.
1349
Tim Peters7a3bfc32001-06-12 01:22:22 +00001350- Many other small changes to dicts were made, resulting in faster
1351 operation along the most common code paths.
1352
Guido van Rossum10315822001-05-01 20:54:30 +00001353- Dictionary objects now support the "in" operator: "x in dict" means
1354 the same as dict.has_key(x).
1355
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001356- The update() method of dictionaries now accepts generic mapping
1357 objects. Specifically the argument object must support the .keys()
1358 and __getitem__() methods. This allows you to say, for example,
1359 {}.update(UserDict())
1360
Guido van Rossum10315822001-05-01 20:54:30 +00001361- Iterators were added; this is a generalized way of providing values
1362 to a for loop. See PEP 234. There's a new built-in function iter()
1363 to return an iterator. There's a new protocol to get the next value
1364 from an iterator using the next() method (in Python) or the
1365 tp_iternext slot (in C). There's a new protocol to get iterators
1366 using the __iter__() method (in Python) or the tp_iter slot (in C).
1367 Iterating (i.e. a for loop) over a dictionary generates its keys.
1368 Iterating over a file generates its lines.
1369
Tim Petersf553f892001-05-01 20:45:31 +00001370- The following functions were generalized to work nicely with iterator
1371 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001372 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001373 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1374 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001375 join() method of strings
1376 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001377 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1378 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001379 right-hand side of assignment statements with multiple targets, such as
1380 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001381
Tim Petersd85e1022001-05-11 21:51:48 +00001382- Accessing module attributes is significantly faster (for example,
1383 random.random or os.path or yourPythonModule.yourAttribute).
1384
Tim Peterse63415e2001-05-08 04:38:29 +00001385- Comparing dictionary objects via == and != is faster, and now works even
1386 if the keys and values don't support comparisons other than ==.
1387
Tim Peters95bf9392001-05-10 08:32:44 +00001388- Comparing dictionaries in ways other than == and != is slower: there were
1389 insecurities in the dict comparison implementation that could cause Python
1390 to crash if the element comparison routines for the dict keys and/or
1391 values mutated the dicts. Making the code bulletproof slowed it down.
1392
Tim Peterseb28ef22001-06-02 05:27:19 +00001393- Collisions in dicts are resolved via a new approach, which can help
1394 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001395 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001396 faster now. Thanks to Christian Tismer for pointing out the cause and
1397 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001398
Tim Peters52e155e2001-06-16 05:42:57 +00001399- repr() is much faster for large containers (dict, list, tuple).
1400
1401
Tim Petersa814db52001-05-14 07:05:58 +00001402Library
1403
Fred Drake960fdf92001-07-20 18:38:26 +00001404- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1405 were added to the string module. These a locale-indenpendent
1406 constants, unlike letters, lowercase, and uppercase. These are now
1407 use in appropriate locations in the standard library.
1408
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001409- The flags used in dlopen calls can now be configured using
1410 sys.setdlopenflags and queried using sys.getdlopenflags.
1411
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001412- Fredrik Lundh's xmlrpclib is now a standard library module. This
1413 provides full client-side XML-RPC support. In addition,
1414 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1415 one asyncore-based). Thanks to Eric Raymond for the documentation.
1416
Guido van Rossum643d3912001-07-05 14:46:25 +00001417- The xrange() object is simplified: it no longer supports slicing,
1418 repetition, comparisons, efficient 'in' checking, the tolist()
1419 method, or the start, stop and step attributes. See PEP 260.
1420
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001421- A new function fnmatch.filter to filter lists of file names was added.
1422
Barry Warsawffd674d2001-05-22 16:00:10 +00001423- calendar.py uses month and day names based on the current locale.
1424
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001425- strop is now *really* obsolete (this was announced before with 1.6),
1426 and issues DeprecationWarning when used (except for the four items
1427 that are still imported into string.py).
1428
Tim Petersa814db52001-05-14 07:05:58 +00001429- Cookie.py now sorts key+value pairs by key in output strings.
1430
1431- pprint.isrecursive(object) didn't correctly identify recursive objects.
1432 Now it does.
1433
Tim Peters95b3f782001-05-14 18:39:41 +00001434- pprint functions now much faster for large containers (tuple, list, dict).
1435
Tim Peters7b9542a2001-06-10 23:40:19 +00001436- New 'q' and 'Q' format codes in the struct module, corresponding to C
1437 types "long long" and "unsigned long long" (on Windows, __int64). In
1438 native mode, these can be used only when the platform C compiler supports
1439 these types (when HAVE_LONG_LONG is #define'd by the Python config
1440 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001441 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1442 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001443
Guido van Rossum83213cc2001-06-12 16:48:52 +00001444- The site module installs a new built-in function 'help' that invokes
1445 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1446 it displays a message reminding the user to use 'help()' or
1447 'help(object)'.
1448
Tim Petersa814db52001-05-14 07:05:58 +00001449Tests
1450
1451- New test_mutants.py runs dict comparisons where the key and value
1452 comparison operators mutute the dicts randomly during comparison. This
1453 rapidly causes Python to crash under earlier releases (not for the faint
1454 of heart: it can also cause Win9x to freeze or reboot!).
1455
1456- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001457 pprint.isreadable() return sensible results. Also verifies that simple
1458 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001459
Tim Peters4324aa32001-05-28 22:30:08 +00001460C API
1461
1462- Removed the unused last_is_sticky argument from the internal
1463 _PyTuple_Resize(). If this affects you, you were cheating.
1464
1465
Guido van Rossum55a78992001-07-17 17:22:32 +00001466======================================================================
1467
1468
Guido van Rossumffe13be2001-04-16 18:46:45 +00001469What's New in Python 2.1 (final)?
1470=================================
1471
1472We only changed a few things since the last release candidate, all in
1473Python library code:
1474
1475- A bug in the locale module was fixed that affected locales which
1476 define no grouping for numeric formatting.
1477
1478- A few bugs in the weakref module's implementations of weak
1479 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1480 and the test suite was updated to check for these bugs.
1481
1482- An old bug in the os.path.walk() function (introduced in Python
1483 2.0!) was fixed: a non-existent file would cause an exception
1484 instead of being ignored.
1485
1486- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1487 PyChecker.
1488
1489
Guido van Rossum5b08f132001-04-16 02:05:23 +00001490What's New in Python 2.1c2?
1491===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001492
Guido van Rossum5b08f132001-04-16 02:05:23 +00001493A flurry of small changes, and one showstopper fixed in the nick of
1494time made it necessary to release another release candidate. The list
1495here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001496
Guido van Rossum5b08f132001-04-16 02:05:23 +00001497Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001498
Guido van Rossum5b08f132001-04-16 02:05:23 +00001499- Tim discovered a nasty bug in the dictionary code, caused by
1500 PyDict_Next() calling dict_resize(), and the GC code's use of
1501 PyDict_Next() violating an assumption in dict_items(). This was
1502 fixed with considerable amounts of band-aid, but the net effect is a
1503 saner and more robust implementation.
1504
1505- Made a bunch of symbols static that were accidentally global.
1506
1507Build and Ports
1508
1509- The setup.py script didn't check for a new enough version of zlib
1510 (1.1.3 is needed). Now it does.
1511
1512- Changed "make clean" target to also remove shared libraries.
1513
1514- Added a more general warning about the SGI Irix optimizer to README.
1515
1516Library
1517
1518- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1519 omitted the slash between host and file.html.
1520
1521- The mailbox module's _Mailbox class contained a completely broken
1522 and undocumented seek() method. Ripped it out.
1523
1524- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1525 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1526
1527- Fixed a few last-minute bugs in unittest.
1528
1529Extensions
1530
1531- Reverted the patch to the OpenSSL code in socketmodule.c to support
1532 RAND_status() and the EGD, and the subsequent patch that tried to
1533 fix it for pre-0.9.5 versions; the problem with the patch is that on
1534 some systems it issues a warning whenever socket is imported, and
1535 that's unacceptable.
1536
1537Tests
1538
1539- Fixed the pickle tests to work with "import test.test_pickle".
1540
1541- Tweaked test_locale.py to actually run the test Windows.
1542
1543- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1544 not "wb" (which is not a valid mode at all).
1545
1546- Fix pstats browser crashes. Import readline if it exists to make
1547 the user interface nicer.
1548
1549- Add "import thread" to the top of test modules that import the
1550 threading module (test_asynchat and test_threadedtempfile). This
1551 prevents test failures caused by a broken threading module resulting
1552 from a previously caught failed import.
1553
1554- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1555 needed on some platforms (e.g. Solaris 8) when the tests are run
1556 twice in succession.
1557
1558- Skip rather than fail test_sunaudiodev if no audio device is found.
1559
1560
1561What's New in Python 2.1c1?
1562===========================
1563
1564This list was significantly updated when 2.1c2 was released; the 2.1c1
1565release didn't mention most changes that were actually part of 2.1c1:
1566
1567Legal
1568
1569- Copyright was assigned to the Python Software Foundation (PSF) and a
1570 PSF license (very similar to the CNRI license) was added.
1571
1572- The CNRI copyright notice was updated to include 2001.
1573
1574Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001575
Guido van Rossumc9932722001-04-12 02:31:27 +00001576- After a public outcry, assignment to __debug__ is no longer illegal;
1577 instead, a warning is issued. It will become illegal in 2.2.
1578
Guido van Rossum5b08f132001-04-16 02:05:23 +00001579- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1580 "%#x" now always prepends "0x", even if the value is zero.
1581
1582- Fixed some nits in the bytecode compiler.
1583
1584- Fixed core dumps when calling certain kinds of non-functions.
1585
1586- Fixed various core dumps caused by reference count bugs.
1587
1588Build and Ports
1589
1590- Use INSTALL_SCRIPT to install script files.
1591
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001592- New port: SCO Unixware 7, by Billy G. Allie.
1593
Guido van Rossum5b08f132001-04-16 02:05:23 +00001594- Updated RISCOS port.
1595
1596- Updated BeOS port and notes.
1597
1598- Various other porting problems resolved.
1599
1600Library
1601
1602- The TERMIOS and SOCKET modules are now truly obsolete and
1603 unnecessary. Their symbols are incorporated in the termios and
1604 socket modules.
1605
1606- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1607 better tests for pickling.
1608
1609- threading: make Condition.wait() robust against KeyboardInterrupt.
1610
1611- zipfile: add support to zipfile to support opening an archive
1612 represented by an open file rather than a file name. Fix bug where
1613 the archive was not properly closed. Fixed a bug in this bugfix
1614 where flush() was called for a read-only file.
1615
1616- imputil: added an uninstall() method to the ImportManager.
1617
1618- Canvas: fixed bugs in lower() and tkraise() methods.
1619
1620- SocketServer: API change (added overridable close_request() method)
1621 so that the TCP server can explicitly close the request.
1622
1623- pstats: Eric Raymond added a simple interactive statistics browser,
1624 invoked when the module is run as a script.
1625
1626- locale: fixed a problem in format().
1627
1628- webbrowser: made it work when the BROWSER environment variable has a
1629 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1630 KDE 2. Fixed some other nits.
1631
1632- unittest: changes to allow using a different exception than
1633 AssertionError, and added a few more function aliases. Some other
1634 small changes.
1635
1636- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1637
1638- asynchat: fixed a critical bug in asynchat that slipped through the
1639 2.1b2 release. Fixed another rare bug.
1640
1641- Fix some unqualified except: clauses (always a bad code example).
1642
1643XML
1644
1645- pyexpat: new API get_version_string().
1646
1647- Fixed some minidom bugs.
1648
1649Extensions
1650
1651- Fixed a core dump in _weakref. Removed the weakref.mapping()
1652 function (it adds nothing to the API).
1653
1654- Rationalized the use of header files in the readline module, to make
1655 it compile (albeit with some warnings) with the very recent readline
1656 4.2, without breaking for earlier versions.
1657
1658- Hopefully fixed a buffering problem in linuxaudiodev.
1659
1660- Attempted a fix to make the OpenSSL support in the socket module
1661 work again with pre-0.9.5 versions of OpenSSL.
1662
1663Tests
1664
1665- Added a test case for asynchat and asyncore.
1666
1667- Removed coupling between tests where one test failing could break
1668 another.
1669
1670Tools
1671
1672- Ping added an interactive help browser to pydoc, fixed some nits
1673 in the rest of the pydoc code, and added some features to his
1674 inspect module.
1675
1676- An updated python-mode.el version 4.1 which integrates Ken
1677 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1678 much nicer in XEmacs and Emacs. When stepping through your program
1679 with pdb, in either the shell window or the *Python* window, the
1680 source file and line will be tracked by an arrow. Very cool!
1681
1682- IDLE: syntax warnings in interactive mode are changed into errors.
1683
1684- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001685 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001686
1687- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001688
Barry Warsaw11e89c72001-04-11 20:37:57 +00001689
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001690What's New in Python 2.1 beta 2?
1691================================
1692
Guido van Rossum053ae352001-03-22 14:17:21 +00001693(Unlisted are many fixed bugs, more documentation, etc.)
1694
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001695Core language, builtins, and interpreter
1696
Guido van Rossum053ae352001-03-22 14:17:21 +00001697- The nested scopes work (enabled by "from __future__ import
1698 nested_scopes") is completed; in particular, the future now extends
1699 into code executed through exec, eval() and execfile(), and into the
1700 interactive interpreter.
1701
1702- When calling a base class method (e.g. BaseClass.__init__(self)),
1703 this is now allowed even if self is not strictly spoken a class
1704 instance (e.g. when using metaclasses or the Don Beaudry hook).
1705
1706- Slice objects are now comparable but not hashable; this prevents
1707 dict[:] from being accepted but meaningless.
1708
1709- Complex division is now calculated using less braindead algorithms.
1710 This doesn't change semantics except it's more likely to give useful
1711 results in extreme cases. Complex repr() now uses full precision
1712 like float repr().
1713
1714- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1715
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001716- It is illegal to assign to the name __debug__, which is set when the
1717 interpreter starts. It is effectively a compile-time constant.
1718
1719- A warning will be issued if a global statement for a variable
1720 follows a use or assignment of that variable.
1721
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001722Standard library
1723
Guido van Rossum053ae352001-03-22 14:17:21 +00001724- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1725 inspired by JUnit), is now part of the standard library. You now
1726 have a choice of two testing frameworks: unittest requires you to
1727 write testcases as separate code, doctest gathers them from
1728 docstrings. Both approaches have their advantages and
1729 disadvantages.
1730
1731- A new module Tix was added, which wraps the Tix extension library
1732 for Tk. With that module, it is not necessary to statically link
1733 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1734 require" command. See Demo/tix/.
1735
1736- tzparse.py is now obsolete.
1737
1738- In gzip.py, the seek() and tell() methods are removed -- they were
1739 non-functional anyway, and it's better if callers can test for their
1740 existence with hasattr().
1741
1742Python/C API
1743
1744- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1745 that's already in the dictionary during a PyDict_Next() iteration.
1746 This used to fail occasionally when a dictionary resize operation
1747 could be triggered that would rehash all the keys. All other
1748 modifications to the dictionary are still off-limits during a
1749 PyDict_Next() iteration!
1750
1751- New extended APIs related to passing compiler variables around.
1752
1753- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1754 implement isinstance() and issubclass().
1755
1756- Py_BuildValue() now has a "D" conversion to create a Python complex
1757 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001758
Fred Drake4e262a92001-03-22 18:26:47 +00001759- Extensions types which support weak references must now set the
1760 field allocated for the weak reference machinery to NULL themselves;
1761 this is done to avoid the cost of checking each object for having a
1762 weakly referencable type in PyObject_INIT(), since most types are
1763 not weakly referencable.
1764
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001765- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1766 free variables and cell variables to and from the frame's f_locals.
1767
1768- Variants of several functions defined in pythonrun.h have been added
1769 to support the nested_scopes future statement. The variants all end
1770 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1771 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1772 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001773 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001774
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001775Distutils
1776
1777- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1778 into the release tree.
1779
Tim Peters0e57abf2001-05-02 07:39:38 +00001780- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001781 (an uninstaller, more customization of the installer's display)
1782
1783- from Jack Jansen: added Mac-specific code to generate a dialog for
1784 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001785 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001786 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001787
1788- added 'platforms' and 'keywords' to the set of metadata that can be
1789 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001790
1791- applied patches from Jason Tishler to make the compiler class work with
1792 Cygwin.
1793
1794
Tim Peters2fe289a2001-03-01 22:19:38 +00001795What's New in Python 2.1 beta 1?
1796================================
Tim Petersd66595f2001-02-04 03:09:53 +00001797
1798Core language, builtins, and interpreter
1799
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001800- Following an outcry from the community about the amount of code
1801 broken by the nested scopes feature introduced in 2.1a2, we decided
1802 to make this feature optional, and to wait until Python 2.2 (or at
1803 least 6 months) to make it standard. The option can be enabled on a
1804 per-module basis by adding "from __future__ import nested_scopes" at
1805 the beginning of a module (before any other statements, but after
1806 comments and an optional docstring). See PEP 236 (Back to the
1807 __future__) for a description of the __future__ statement. PEP 227
1808 (Statically Nested Scopes) has been updated to reflect this change,
1809 and to clarify the semantics in a number of endcases.
1810
1811- The nested scopes code, when enabled, has been hardened, and most
1812 bugs and memory leaks in it have been fixed.
1813
1814- Compile-time warnings are now generated for a number of conditions
1815 that will break or change in meaning when nested scopes are enabled:
1816
1817 - Using "from...import *" or "exec" without in-clause in a function
1818 scope that also defines a lambda or nested function with one or
1819 more free (non-local) variables. The presence of the import* or
1820 bare exec makes it impossible for the compiler to determine the
1821 exact set of local variables in the outer scope, which makes it
1822 impossible to determine the bindings for free variables in the
1823 inner scope. To avoid the warning about import *, change it into
1824 an import of explicitly name object, or move the import* statement
1825 to the global scope; to avoid the warning about bare exec, use
1826 exec...in... (a good idea anyway -- there's a possibility that
1827 bare exec will be deprecated in the future).
1828
1829 - Use of a global variable in a nested scope with the same name as a
1830 local variable in a surrounding scope. This will change in
1831 meaning with nested scopes: the name in the inner scope will
1832 reference the variable in the outer scope rather than the global
1833 of the same name. To avoid the warning, either rename the outer
1834 variable, or use a global statement in the inner function.
1835
Neil Schemenauera35c6882001-02-27 04:45:05 +00001836- An optional object allocator has been included. This allocator is
1837 optimized for Python objects and should be faster and use less memory
1838 than the standard system allocator. It is not enabled by default
1839 because of possible thread safety problems. The allocator is only
1840 protected by the Python interpreter lock and it is possible that some
1841 extension modules require a thread safe allocator. The object
1842 allocator can be enabled by providing the "--with-pymalloc" option to
1843 configure.
1844
Tim Petersd66595f2001-02-04 03:09:53 +00001845Standard library
1846
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001847- pyexpat now detects the expat version if expat.h defines it. A
1848 number of additional handlers are provided, which are only available
1849 since expat 1.95. In addition, the methods SetParamEntityParsing and
1850 GetInputContext of Parser objects are available with 1.95.x
1851 only. Parser objects now provide the ordered_attributes and
1852 specified_attributes attributes. A new module expat.model was added,
1853 which offers a number of additional constants if 1.95.x is used.
1854
1855- xml.dom offers the new functions registerDOMImplementation and
1856 getDOMImplementation.
1857
1858- xml.dom.minidom offers a toprettyxml method. A number of DOM
1859 conformance issues have been resolved. In particular, Element now
1860 has an hasAttributes method, and the handling of namespaces was
1861 improved.
1862
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001863- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1864 getting information about live Python code, and pydoc.py, a module
1865 for interactively converting docstrings to HTML or text.
1866 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001867 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001868 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1869 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001870
Tim Peters1eff7962001-03-01 02:31:33 +00001871- New library module difflib.py, primarily packaging the SequenceMatcher
1872 class at the heart of the popular ndiff.py file-comparison tool.
1873
1874- doctest.py (a framework for verifying Python code examples in docstrings)
1875 is now part of the std library.
1876
Tim Petersd66595f2001-02-04 03:09:53 +00001877Windows changes
1878
Guido van Rossume3955a82001-03-02 14:05:59 +00001879- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1880 small GUI that lets you browse the module docstrings using your
1881 default web browser.
1882
Tim Peters1eff7962001-03-01 02:31:33 +00001883- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1884 Platforms) is implemented. See
1885
1886 http://python.sourceforge.net/peps/pep-0235.html
1887
1888 for full details, especially the "Current Lower-Left Semantics" section.
1889 The new Windows import rules are simpler than before:
1890
1891 A. If the PYTHONCASEOK environment variable exists, same as
1892 before: silently accept the first case-insensitive match of any
1893 kind; raise ImportError if none found.
1894
1895 B. Else search sys.path for the first case-sensitive match; raise
1896 ImportError if none found.
1897
1898 The same rules have been implented on other platforms with case-
1899 insensitive but case-preserving filesystems too (including Cygwin, and
1900 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001901
Tim Peters25a9ce32001-02-19 07:06:36 +00001902- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1903 what it's supposed to do (and does do under NT and 2000) via direct
1904 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001905 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001906 all Win9x systems before.
1907
Tim Peters1eff7962001-03-01 02:31:33 +00001908- Build: Subproject _test (effectively) renamed to _testcapi.
1909
Tim Peters2fe289a2001-03-01 22:19:38 +00001910New platforms
1911
1912- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1913 Thanks to Steven Majewski!
1914
1915- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1916 Tishler!
1917
Guido van Rossum9089b272001-03-02 06:49:50 +00001918- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1919 Schwertberger! See RISCOS/README for more information -- it seems
1920 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001921 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001922
Tim Peters25a9ce32001-02-19 07:06:36 +00001923
Tim Petersd7b5e882001-01-25 03:36:26 +00001924What's New in Python 2.1 alpha 2?
1925=================================
Tim Peters40ead762001-01-27 05:35:26 +00001926
Tim Petersd7b5e882001-01-25 03:36:26 +00001927Core language, builtins, and interpreter
1928
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001929- Scopes nest. If a name is used in a function or class, but is not
1930 local, the definition in the nearest enclosing function scope will
1931 be used. One consequence of this change is that lambda statements
1932 could reference variables in the namespaces where the lambda is
1933 defined. In some unusual cases, this change will break code.
1934
1935 In all previous version of Python, names were resolved in exactly
1936 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001937 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001938 function A is defined within a function B, the names bound in B are
1939 not visible in A. The new rules make names bound in B visible in A,
1940 unless A contains a name binding that hides the binding in B.
1941
1942 Section 4.1 of the reference manual describes the new scoping rules
1943 in detail. The test script in Lib/test/test_scope.py demonstrates
1944 some of the effects of the change.
1945
1946 The new rules will cause existing code to break if it defines nested
1947 functions where an outer function has local variables with the same
1948 name as globals or builtins used by the inner function. Example:
1949
1950 def munge(str):
1951 def helper(x):
1952 return str(x)
1953 if type(str) != type(''):
1954 str = helper(str)
1955 return str.strip()
1956
1957 Under the old rules, the name str in helper() is bound to the
1958 builtin function str(). Under the new rules, it will be bound to
1959 the argument named str and an error will occur when helper() is
1960 called.
1961
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001962- The compiler will report a SyntaxError if "from ... import *" occurs
1963 in a function or class scope. The language reference has documented
1964 that this case is illegal, but the compiler never checked for it.
1965 The recent introduction of nested scope makes the meaning of this
1966 form of name binding ambiguous. In a future release, the compiler
1967 may allow this form when there is no possibility of ambiguity.
1968
Tim Peters40ead762001-01-27 05:35:26 +00001969- repr(string) is easier to read, now using hex escapes instead of octal,
1970 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1971
1972 >>> "\texample \r\n" + chr(0) + chr(255)
1973 '\texample \r\n\x00\xff' # in 2.1
1974 '\011example \015\012\000\377' # in 2.0
1975
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001976- Functions are now compared and hashed by identity, not by value, since
1977 the func_code attribute is writable.
1978
Fred Drakefb9d7122001-02-01 20:00:40 +00001979- Weak references (PEP 205) have been added. This involves a few
1980 changes in the core, an extension module (_weakref), and a Python
1981 module (weakref). The weakref module is the public interface. It
1982 includes support for "explicit" weak references, proxy objects, and
1983 mappings with weakly held values.
1984
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001985- A 'continue' statement can now appear in a try block within the body
1986 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001987 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001988
Tim Petersd7b5e882001-01-25 03:36:26 +00001989Standard library
1990
Barry Warsaw30dbd142001-01-31 22:14:01 +00001991- mailbox.py now has a new class, PortableUnixMailbox which is
1992 identical to UnixMailbox but uses a more portable scheme for
1993 determining From_ separators. Also, the constructors for all the
1994 classes in this module have a new optional `factory' argument, which
1995 is a callable used when new message classes must be instantiated by
1996 the next() method.
1997
Tim Petersd7b5e882001-01-25 03:36:26 +00001998- random.py is now self-contained, and offers all the functionality of
1999 the now-deprecated whrandom.py. See the docs for details. random.py
2000 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002001 and restoring the internal state of the generator; and jumpahead(n),
2002 for quickly forcing the internal state to be the same as if n calls to
2003 random() had been made. The latter is particularly useful for multi-
2004 threaded programs, creating one instance of the random.Random() class for
2005 each thread, then using .jumpahead() to force each instance to use a
2006 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002007
Tim Peters0de88fc2001-02-01 04:59:18 +00002008- random.py's seed() function is new. For bit-for-bit compatibility with
2009 prior releases, use the whseed function instead. The new seed function
2010 addresses two problems: (1) The old function couldn't produce more than
2011 about 2**24 distinct internal states; the new one about 2**45 (the best
2012 that can be done in the Wichmann-Hill generator). (2) The old function
2013 sometimes produced identical internal states when passed distinct
2014 integers, and there was no simple way to predict when that would happen;
2015 the new one guarantees to produce distinct internal states for all
2016 arguments in [0, 27814431486576L).
2017
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002018- The socket module now supports raw packets on Linux. The socket
2019 family is AF_PACKET.
2020
Tim Peters9ea17ac2001-02-02 05:57:15 +00002021- test_capi.py is a start at running tests of the Python C API. The tests
2022 are implemented by the new Modules/_testmodule.c.
2023
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002024- A new extension module, _symtable, provides provisional access to the
2025 internal symbol table used by the Python compiler. A higher-level
2026 interface will be added on top of _symtable in a future release.
2027
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002028- Removed the obsolete soundex module.
2029
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002030- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2031 the isSameNode method; NamedNodeMap the get method.
2032
2033- xml.sax.expatreader supports the lexical handler property; it
2034 generates comment, startCDATA, and endCDATA events.
2035
Tim Petersee826f82001-01-31 19:39:44 +00002036Windows changes
2037
2038- Build procedure: the zlib project is built in a different way that
2039 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002040 the zlib binary used. See PCbuild\readme.txt for details. Your old
2041 zlib-related directories can be deleted; you'll need to download fresh
2042 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002043
Tim Peters9ea17ac2001-02-02 05:57:15 +00002044- Build: New subproject _test for the benefit of test_capi.py (see above).
2045
Tim Petersb16c56f2001-02-02 21:24:51 +00002046- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2047 interface to some Python compiler internals).
2048
2049- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002050 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002051
Tim Petersa3a3a032000-11-30 05:22:44 +00002052What's New in Python 2.1 alpha 1?
2053=================================
2054
2055Core language, builtins, and interpreter
2056
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002057- There is a new Unicode companion to the PyObject_Str() API
2058 called PyObject_Unicode(). It behaves in the same way as the
2059 former, but assures that the returned value is an Unicode object
2060 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002061
Guido van Rossumf98eda02001-01-17 15:54:45 +00002062- The comparison operators support "rich comparison overloading" (PEP
2063 207). C extension types can provide a rich comparison function in
2064 the new tp_richcompare slot in the type object. The cmp() function
2065 and the C function PyObject_Compare() first try the new rich
2066 comparison operators before trying the old 3-way comparison. There
2067 is also a new C API PyObject_RichCompare() (which also falls back on
2068 the old 3-way comparison, but does not constrain the outcome of the
2069 rich comparison to a Boolean result).
2070
2071 The rich comparison function takes two objects (at least one of
2072 which is guaranteed to have the type that provided the function) and
2073 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2074 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2075 object, which may be NotImplemented (in which case the tp_compare
2076 slot function is used as a fallback, if defined).
2077
2078 Classes can overload individual comparison operators by defining one
2079 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002080 __ge__. There are no explicit "reflected argument" versions of
2081 these; instead, __lt__ and __gt__ are each other's reflection,
2082 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2083 reflection (similar at the C level). No other implications are
2084 made; in particular, Python does not assume that == is the Boolean
2085 inverse of !=, or that < is the Boolean inverse of >=. This makes
2086 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002087
2088 Classes or types that want to implement (in)equality tests but not
2089 the ordering operators (i.e. unordered types) should implement ==
2090 and !=, and raise an error for the ordering operators.
2091
Guido van Rossuma88479f2001-01-18 14:28:08 +00002092 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002093 Boolean; e.g. a matrix type might want to return a matrix of bits
2094 for A < B, giving elementwise comparisons. Such types should ensure
2095 that any interpretation of their value in a Boolean context raises
2096 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2097 at the C level) to always raise an exception.
2098
Guido van Rossuma88479f2001-01-18 14:28:08 +00002099- Complex numbers use rich comparisons to define == and != but raise
2100 an exception for <, <=, > and >=. Unfortunately, this also means
2101 that cmp() of two complex numbers raises an exception when the two
2102 numbers differ. Since it is not mathematically meaningful to compare
2103 complex numbers except for equality, I hope that this doesn't break
2104 too much code.
2105
Tim Peters3389f192001-02-18 08:48:49 +00002106- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002107 not defined by the language, other than that it's arbitrary but
2108 consistent (see the Reference Manual). An implementation detail changed
2109 in 2.1a1 such that None now compares less than any other object. Code
2110 relying on this new behavior (like code that relied on the previous
2111 behavior) does so at its own risk.
2112
Barry Warsaw573b5412001-01-15 20:43:18 +00002113- Functions and methods now support getting and setting arbitrarily
2114 named attributes (PEP 232). Functions have a new __dict__
2115 (a.k.a. func_dict) which hold the function attributes. Methods get
2116 and set attributes on their underlying im_func. It is a TypeError
2117 to set an attribute on a bound method.
2118
Guido van Rossum051e3352001-01-15 19:11:10 +00002119- The xrange() object implementation has been improved so that
2120 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2121 limitation that in this case len(xrange(sys.maxint)) can't be
2122 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2123 work fine as long as the index i doesn't actually reach 2**31.
2124 (Python uses regular ints for sequence and string indices; fixing
2125 that is much more work.)
2126
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002127- Two changes to from...import:
2128
Guido van Rossumba381232001-02-03 15:06:40 +00002129 1) "from M import X" now works even if (after loading module M)
2130 sys.modules['M'] is not a real module; it's basically a getattr()
2131 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002132
2133 2) "from M import *" now looks for M.__all__ to decide which names to
2134 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2135 filters out names starting with '_' as before. Whether or not
2136 __all__ exists, there's no restriction on the type of M.
2137
Guido van Rossumf61f1662001-01-10 20:13:55 +00002138- File objects have a new method, xreadlines(). This is the fastest
2139 way to iterate over all lines in a file:
2140
2141 for line in file.xreadlines():
2142 ...do something to line...
2143
2144 See the xreadlines module (mentioned below) for how to do this for
2145 other file-like objects.
2146
2147- Even if you don't use file.xreadlines(), you may expect a speedup on
2148 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002149 quite a bit in platform-specific ways: on systems (like Linux) that
2150 support flockfile(), getc_unlocked(), and funlockfile(), those are
2151 used by default. On systems (like Windows) without getc_unlocked(),
2152 a complicated (but still thread-safe) method using fgets() is used by
2153 default.
2154
Tim Petersd52269b2001-01-25 06:23:18 +00002155 You can force use of the fgets() method by #define'ing
2156 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002157 getc_unlocked()).
2158
Tim Petersd52269b2001-01-25 06:23:18 +00002159 You can force fgets() not to be used by #define'ing
2160 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002161 test_bufio.py fails -- and let us know if it does!).
2162
2163- In addition, the fileinput module, while still slower than the other
2164 methods on most platforms, has been sped up too, by using
2165 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002166
2167- Support for run-time warnings has been added, including a new
2168 command line option (-W) to specify the disposition of warnings.
2169 See the description of the warnings module below.
2170
2171- Extensive changes have been made to the coercion code. This mostly
2172 affects extension modules (which can now implement mixed-type
2173 numerical operators without having to use coercion), but
2174 occasionally, in boundary cases the coercion semantics have changed
2175 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002176 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002177 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002178 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002179
Guido van Rossumf98eda02001-01-17 15:54:45 +00002180- In connection with the coercion changes, a new built-in singleton
2181 object, NotImplemented is defined. This can be returned for
2182 operations that wish to indicate they are not implemented for a
2183 particular combination of arguments. From C, this is
2184 Py_NotImplemented.
2185
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002186- The interpreter accepts now bytecode files on the command line even
2187 if they do not have a .pyc or .pyo extension. On Linux, after executing
2188
Martin v. Löwise214baa2001-02-04 22:37:56 +00002189import imp,sys,string
2190magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2191reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2192open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002193
2194 any byte code file can be used as an executable (i.e. as an argument
2195 to execve(2)).
2196
Tim Peters9940b802000-12-01 07:59:35 +00002197- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002198 character. In 1.6 and earlier, they never produced a sign,
2199 and raised an error if the value of the long was too large
2200 to fit in a Python int. In 2.0, they produced a sign if and
2201 only if too large to fit in an int. This was inconsistent
2202 across platforms (because the size of an int varies across
2203 platforms), and inconsistent with hex() and oct(). Example:
2204
2205 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002206 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002207 'ffffffbe' # in 2.0 and before, on 32-bit machines
2208 >>> hex(-0x42L)
2209 '-0x42L' # in all versions of Python
2210
Tim Peters9940b802000-12-01 07:59:35 +00002211 The behavior of %d formats for negative Python longs remains
2212 the same as in 2.0 (although in 1.6 and before, they raised
2213 an error if the long didn't fit in a Python int).
2214
2215 %u formats don't make sense for Python longs, but are allowed
2216 and treated the same as %d in 2.1. In 2.0, a negative long
2217 formatted via %u produced a sign if and only if too large to
2218 fit in an int. In 1.6 and earlier, a negative long formatted
2219 via %u raised an error if it was too big to fit in an int.
2220
Guido van Rossum3661d392000-12-12 22:10:31 +00002221- Dictionary objects have an odd new method, popitem(). This removes
2222 an arbitrary item from the dictionary and returns it (in the form of
2223 a (key, value) pair). This can be useful for algorithms that use a
2224 dictionary as a bag of "to do" items and repeatedly need to pick one
2225 item. Such algorithms normally end up running in quadratic time;
2226 using popitem() they can usually be made to run in linear time.
2227
Tim Peters36cdad12000-12-29 02:06:45 +00002228Standard library
2229
Thomas Woutersfe385252001-01-19 23:16:56 +00002230- In the time module, the time argument to the functions strftime,
2231 localtime, gmtime, asctime and ctime is now optional, defaulting to
2232 the current time (in the local timezone).
2233
Guido van Rossumda91f222001-01-15 16:36:08 +00002234- The ftplib module now defaults to passive mode, which is deemed a
2235 more useful default given that clients are often inside firewalls
2236 these days. Note that this could break if ftplib is used to connect
2237 to a *server* that is inside a firewall, from outside; this is
2238 expected to be a very rare situation. To fix that, you can call
2239 ftp.set_pasv(0).
2240
Martin v. Löwis10a27872001-01-13 09:54:41 +00002241- The module site now treats .pth files not only for path configuration,
2242 but also supports extensions to the initialization code: Lines starting
2243 with import are executed.
2244
Guido van Rossumf61f1662001-01-10 20:13:55 +00002245- There's a new module, warnings, which implements a mechanism for
2246 issuing and filtering warnings. There are some new built-in
2247 exceptions that serve as warning categories, and a new command line
2248 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2249 turns warnings into errors). warnings.warn(message[, category])
2250 issues a warning message; this can also be called from C as
2251 PyErr_Warn(category, message).
2252
2253- A new module xreadlines was added. This exports a single factory
2254 function, xreadlines(). The intention is that this code is the
2255 absolutely fastest way to iterate over all lines in an open
2256 file(-like) object:
2257
2258 import xreadlines
2259 for line in xreadlines.xreadlines(file):
2260 ...do something to line...
2261
2262 This is equivalent to the previous the speed record holder using
2263 file.readlines(sizehint). Note that if file is a real file object
2264 (as opposed to a file-like object), this is equivalent:
2265
2266 for line in file.xreadlines():
2267 ...do something to line...
2268
Tim Peters36cdad12000-12-29 02:06:45 +00002269- The bisect module has new functions bisect_left, insort_left,
2270 bisect_right and insort_right. The old names bisect and insort
2271 are now aliases for bisect_right and insort_right. XXX_right
2272 and XXX_left methods differ in what happens when the new element
2273 compares equal to one or more elements already in the list: the
2274 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002275 right. Code that doesn't care where equal elements end up should
2276 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002277
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002278- The new curses.panel module wraps the panel library that forms part
2279 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2280
Guido van Rossumf61f1662001-01-10 20:13:55 +00002281- The SocketServer module now sets the allow_reuse_address flag by
2282 default in the TCPServer class.
2283
2284- A new function, sys._getframe(), returns the stack frame pointer of
2285 the caller. This is intended only as a building block for
2286 higher-level mechanisms such as string interpolation.
2287
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002288- The pyexpat module supports a number of new handlers, which are
2289 available only in expat 1.2. If invocation of a callback fails, it
2290 will report an additional frame in the traceback. Parser objects
2291 participate now in garbage collection. If expat reports an unknown
2292 encoding, pyexpat will try to use a Python codec; that works only
2293 for single-byte charsets. The parser type objects is exposed as
2294 XMLParserObject.
2295
2296- xml.dom now offers standard definitions for symbolic node type and
2297 exception code constants, and a hierarchy of DOM exceptions. minidom
2298 was adjusted to use them.
2299
2300- The conformance of xml.dom.minidom to the DOM specification was
2301 improved. It detects a number of additional error cases; the
2302 previous/next relationship works even when the tree is modified;
2303 Node supports the normalize() method; NamedNodeMap, DocumentType and
2304 DOMImplementation classes were added; Element supports the
2305 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2306 method.
2307
Guido van Rossumf61f1662001-01-10 20:13:55 +00002308Build issues
2309
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002310- For Unix (and Unix-compatible) builds, configuration and building of
2311 extension modules is now greatly automated. Rather than having to
2312 edit the Modules/Setup file to indicate which modules should be
2313 built and where their include files and libraries are, a
2314 distutils-based setup.py script now takes care of building most
2315 extension modules. All extension modules built this way are built
2316 as shared libraries. Only a few modules that must be linked
2317 statically are still listed in the Setup file; you won't need to
2318 edit their configuration.
2319
2320- Python should now build out of the box on Cygwin. If it doesn't,
2321 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002322
2323- Python now always uses its own (renamed) implementation of getopt()
2324 -- there's too much variation among C library getopt()
2325 implementations.
2326
2327- C++ compilers are better supported; the CXX macro is always set to a
2328 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002329
Tim Petersd92dfe02000-12-12 01:18:41 +00002330Windows changes
2331
2332- select module: By default under Windows, a select() call
2333 can specify no more than 64 sockets. Python now boosts
2334 this Microsoft default to 512. If you need even more than
2335 that, see the MS docs (you'll need to #define FD_SETSIZE
2336 and recompile Python from source).
2337
Guido van Rossumf61f1662001-01-10 20:13:55 +00002338- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2339 subdirectory is no more!
2340
Tim Petersa3a3a032000-11-30 05:22:44 +00002341
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002342What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002343=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002344
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002345Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002346changes are in the file HISTORY. If you are making the jump directly
2347from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2348HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002349
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002350Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2351the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2352http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002353
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002354--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002355
2356======================================================================
2357
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002358What's new in 2.0 (since release candidate 1)?
2359==============================================
2360
2361Standard library
2362
2363- The copy_reg module was modified to clarify its intended use: to
2364 register pickle support for extension types, not for classes.
2365 pickle() will raise a TypeError if it is passed a class.
2366
2367- Fixed a bug in gettext's "normalize and expand" code that prevented
2368 it from finding an existing .mo file.
2369
2370- Restored support for HTTP/0.9 servers in httplib.
2371
Tim Peters989b7b92000-10-16 20:24:53 +00002372- The math module was changed to stop raising OverflowError in case of
2373 underflow, and return 0 instead in underflow cases. Whether Python
2374 used to raise OverflowError in case of underflow was platform-
2375 dependent (it did when the platform math library set errno to ERANGE
2376 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002377
2378- Fixed a bug in StringIO that occurred when the file position was not
2379 at the end of the file and write() was called with enough data to
2380 extend past the end of the file.
2381
2382- Fixed a bug that caused Tkinter error messages to get lost on
2383 Windows. The bug was fixed by replacing direct use of
2384 interp->result with Tcl_GetStringResult(interp).
2385
2386- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2387 redirect response.
2388
2389- Several changes were made to distutils: Some debugging code was
2390 removed from util. Fixed the installer used when an external zip
2391 program (like WinZip) is not found; the source code for this
2392 installer is in Misc/distutils. check_lib() was modified to behave
2393 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2394 test for whether installed modules are on sys.path was changed to
2395 use both normcase() and normpath().
2396
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002397- Several minor bugs were fixed in the xml package (the minidom,
2398 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002399
2400- The regression test driver (regrtest.py) behavior when invoked with
2401 -l changed: It now reports a count of objects that are recognized as
2402 garbage but not freed by the garbage collector.
2403
Tim Peters989b7b92000-10-16 20:24:53 +00002404- The regression test for the math module was changed to test
2405 exceptional behavior when the test is run in verbose mode. Python
2406 cannot yet guarantee consistent exception behavior across platforms,
2407 so the exception part of test_math is run only in verbose mode, and
2408 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002409
2410Internals
2411
2412- PyOS_CheckStack() has been disabled on Win64, where it caused
2413 test_sre to fail.
2414
2415Build issues
2416
2417- Changed compiler flags, so that gcc is always invoked with -Wall and
2418 -Wstrict-prototypes. Users compiling Python with GCC should see
2419 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002420 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002421 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002422
Tim Petersa3a3a032000-11-30 05:22:44 +00002423- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002424
2425Tools and other miscellany
2426
2427- The compiler in Tools/compiler was updated to support the new
2428 language features introduced in 2.0: extended print statement, list
2429 comprehensions, and augmented assignments. The new compiler should
2430 also be backwards compatible with Python 1.5.2; the compiler will
2431 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002432 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002433
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002434What's new in 2.0 release candidate 1 (since beta 2)?
2435=====================================================
2436
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002437What is release candidate 1?
2438
2439We believe that release candidate 1 will fix all known bugs that we
2440intend to fix for the 2.0 final release. This release should be a bit
2441more stable than the previous betas. We would like to see even more
2442widespread testing before the final release, so we are producing this
2443release candidate. The final release will be exactly the same unless
2444any show-stopping (or brown bag) bugs are found by testers of the
2445release candidate.
2446
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002447All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002448to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002449
2450Core language, builtins, and interpreter
2451
2452- A bug that caused crashes when __coerce__ was used with augmented
2453 assignment, e.g. +=, was fixed.
2454
2455- Raise ZeroDivisionError when raising zero to a negative number,
2456 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2457 power operator and the result of math.pow(0.0, -2.0) will vary by
2458 platform. On Linux, it raises a ValueError.
2459
2460- A bug in Unicode string interpolation was fixed that occasionally
2461 caused errors with formats including "%%". For example, the
2462 following expression "%% %s" % u"abc" no longer raises a TypeError.
2463
2464- Compilation of deeply nested expressions raises MemoryError instead
2465 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2466
2467- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2468 rendering them useless. They are now written in binary mode again.
2469
2470Standard library
2471
2472- Keyword arguments are now accepted for most pattern and match object
2473 methods in SRE, the standard regular expression engine.
2474
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002475- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002476 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002477
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002478- Several bugs in the Unicode handling and error handling in _tkinter
2479 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002480
2481- Fix memory management errors in Merge() and Tkapp_Call() routines.
2482
2483- Several changes were made to cStringIO to make it compatible with
2484 the file-like object interface and with StringIO. If operations are
2485 performed on a closed object, an exception is raised. The truncate
2486 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002487 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002488
2489- There were many changes made to the linuxaudiodev module and its
2490 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002491 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002492
2493 Note that this module is named poorly, because it should work
2494 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002495 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002496
2497 The module now raises exceptions when errors occur instead of
2498 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2499 audio) and defines a getptr() method that calls the
2500 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2501
2502- The library_version attribute, introduced in an earlier beta, was
2503 removed because it can not be supported with early versions of the C
2504 readline library, which provides no way to determine the version at
2505 compile-time.
2506
2507- The binascii module is now enabled on Win64.
2508
Tim Peters46446d62000-10-09 21:19:31 +00002509- tokenize.py no longer suffers "recursion depth" errors when parsing
2510 programs with very long string literals.
2511
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002512Internals
2513
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002514- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002515 which is called when the interpreter starts up to determine where
2516 the standard library is installed. These vulnerabilities affect all
2517 previous versions of Python and can be exploited by setting very
2518 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2519 setuid Python script, although use of the wrapper in
2520 Misc/setuid-prog.c will eliminate the vulnerability.
2521
2522- Fixed garbage collection bugs in instance creation that were
2523 triggered when errors occurred during initialization. The solution,
2524 applied in cPickle and in PyInstance_New(), is to call
2525 PyObject_GC_Init() after the initialization of the object's
2526 container attributes is complete.
2527
2528- pyexpat adds definitions of PyModule_AddStringConstant and
2529 PyModule_AddObject if the Python version is less than 2.0, which
2530 provides compatibility with PyXML on Python 1.5.2.
2531
2532- If the platform has a bogus definition for LONG_BIT (the number of
2533 bits in a long), an error will be reported at compile time.
2534
2535- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2536 collection crashes and possibly other, unreported crashes.
2537
2538- Fixed a memory leak in _PyUnicode_Fini().
2539
2540Build issues
2541
2542- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002543 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002544 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002545
2546- The mmap.PAGESIZE constant is now initialized using sysconf when
2547 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2548
2549- The md5 file should now compile on all platforms.
2550
2551- The select module now compiles on platforms that do not define
2552 POLLRDNORM and related constants.
2553
2554- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002555 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002556
Jeremy Hylton10921202000-10-09 18:34:12 +00002557- BeOS: A number of changes were made to the build and installation
2558 process. ar-fake now operates on a directory of object files.
2559 dl_export.h is gone, and its macros now appear on the mwcc command
2560 line during build on PPC BeOS.
2561
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002562- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002563 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002564
2565- Cygwin: Support for shared libraries, Tkinter, and sockets.
2566
2567- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2568
2569Tools and other miscellany
2570
2571- Removed debugging prints from main used with freeze.
2572
Tim Peters46446d62000-10-09 21:19:31 +00002573- IDLE auto-indent no longer crashes when it encounters Unicode
2574 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002575
2576What's new in 2.0 beta 2 (since beta 1)?
2577========================================
2578
2579Core language, builtins, and interpreter
2580
Tim Peters482c0212000-09-26 06:33:09 +00002581- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002582 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002583
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002584- Add -h and -V command line options to print the usage message and
2585 Python version number and exit immediately.
2586
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002587- eval() and exec accept Unicode objects as code parameters.
2588
2589- getattr() and setattr() now also accept Unicode objects for the
2590 attribute name, which are converted to strings using the default
2591 encoding before lookup.
2592
2593- Multiplication on string and Unicode now does proper bounds
2594 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2595 string is too long."
2596
2597- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002598 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002599
Jeremy Hylton1b618592000-09-26 05:32:36 +00002600
2601Standard library and extensions
2602
Guido van Rossum5b08f132001-04-16 02:05:23 +00002603- socket module: the OpenSSL code now adds support for RAND_status()
2604 and EGD (Entropy Gathering Device).
2605
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002606- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002607 argument checking; it still takes no arguments.
2608
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002609- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002610
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002611- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002612
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002613- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002614
2615- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002616 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002617
2618- copy: Copy Unicode objects atomically.
2619
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002620- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002621
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002622- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002623
Fred Drake67233bc2000-09-26 16:40:27 +00002624- dbm: Add get() and setdefault() methods to dbm object. Add constant
2625 `library' to module that names the library used. Added doc strings
2626 and method names to error messages. Uses configure to determine
2627 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2628 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002629
2630- distutils: Update to version 0.9.3.
2631
2632- dl: Add several dl.RTLD_ constants.
2633
2634- fpectl: Now supported on FreeBSD.
2635
2636- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2637 found by the collector will be saved in gc.garbage. This is useful
2638 for debugging a program that creates reference cycles.
2639
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002640- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002641 of HTTP class. Do not close socket on zero-length response. Do not
2642 crash when server sends invalid content-length header.
2643
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002644- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002645
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002646- marshal: When reading a short, sign-extend on platforms where shorts
2647 are bigger than 16 bits. When reading a long, repair the unportable
2648 sign extension that was being done for 64-bit machines. (It assumed
2649 that signed right shift sign-extends.)
2650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002651- operator: Add contains(), invert(), __invert__() as aliases for
2652 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002653
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002654- os: Add support for popen2() and popen3() on all platforms where
2655 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002656
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002657- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002658 clicking on a file in Explorer (or passing the file name to the
2659 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002660
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002661- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002662 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002663
2664- pickle: Now raises ValueError when an invalid pickle that contains
2665 a non-string repr where a string repr was expected. This behavior
2666 matches cPickle.
2667
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002668- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002669
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002670- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671
2672- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002673 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002674 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002675
2676- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002677 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002678
2679- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002680 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002681 few cycles during startup since the first call to
2682 setdefaultencoding() will initialize the codec registry and the
2683 encodings package.
2684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685- socket: Support for size hint in readlines() method of object returned
2686 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002688- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002689 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002690 is followed by whitespace.
2691
Tim Petersa3a3a032000-11-30 05:22:44 +00002692- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002693
2694- struct: Check ranges for bytes and shorts.
2695
2696- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002697 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002698
2699- Tkinter: Image objects are now guaranteed to have unique ids. Set
2700 event.delta to zero if Tk version doesn't support mousewheel.
2701 Removed some debugging prints.
2702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002703- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002704
Fred Drake67233bc2000-09-26 16:40:27 +00002705- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002706 which works around a bug in Norton AntiVirus 2000 that leads directly
2707 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002708
2709- xml: New version detection code allows PyXML to override standard
2710 XML package if PyXML version is greater than 0.6.1.
2711
Fred Drake64bb3802000-09-26 16:21:35 +00002712- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2713 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2714 tree only for nodes which are sufficiently interesting to a specific
2715 application. Does not provide the HTML-specific extensions. Still
2716 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002717
Fred Drake64bb3802000-09-26 16:21:35 +00002718- xml.sax: SAX 2 support for Python, including all the handler
2719 interfaces needed to process XML 1.0 compliant XML. Some
2720 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721
Fred Drake64bb3802000-09-26 16:21:35 +00002722- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2723 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002724
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002725
Jeremy Hylton1b618592000-09-26 05:32:36 +00002726C API
2727
2728- Add three new convenience functions for module initialization --
2729 PyModule_AddObject(), PyModule_AddIntConstant(), and
2730 PyModule_AddStringConstant().
2731
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002732- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002733 removed and add #error to Python.h if NULL isn't defined after
2734 #include of stdio.h.
2735
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002736- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002737 backwards compatibility (at the source level) with old extensions.
2738
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002739- A wrapper API was added for signal() and sigaction(). Instead of
2740 either function, always use PyOS_getsig() to get a signal handler
2741 and PyOS_setsig() to set one. A new convenience typedef
2742 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002743
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002744- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002745 internal data buffer and size of a string object -- or the default
2746 encoded version of a Unicode object.
2747
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002748- PyString_Size() and PyString_AsString() accept Unicode objects.
2749
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002750- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002751 exists). INT_MAX and LONG_MAX will always be defined, even if
2752 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002753
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002754- PyFloat_FromString takes a second argument, pend, that was
2755 effectively useless. It is now officially useless but preserved for
2756 backwards compatibility. If the pend argument is not NULL, *pend is
2757 set to NULL.
2758
2759- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2760 for the attribute name. See note on getattr() above.
2761
2762- A few bug fixes to argument processing for Unicode.
2763 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2764 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2765 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002766 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002767
2768- Py_BuildValue accepts B format (for bgen-generated code).
2769
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002770
Jeremy Hylton1b618592000-09-26 05:32:36 +00002771Internals
2772
2773- On Unix, fix code for finding Python installation directory so that
2774 it works when argv[0] is a relative path.
2775
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002776- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002777 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002778 rather than by generating a copy of the object.
2779
Tim Peters482c0212000-09-26 06:33:09 +00002780- Several of the internal Unicode tables are much smaller now, and
2781 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002782
Jeremy Hylton97693b02000-09-26 17:42:51 +00002783- In the garbage collector: Fixed bug in collection of tuples. Fixed
2784 bug that caused some instances to be removed from the container set
2785 while they were still live. Fixed parsing in gc.set_debug() for
2786 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002787
2788- Fixed refcount problem in instance deallocation that only occurred
2789 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2790
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002791- On Windows, getpythonregpath is now protected against null data in
2792 registry key.
2793
2794- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002795 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002796
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002797
Jeremy Hylton1b618592000-09-26 05:32:36 +00002798Build and platform-specific issues
2799
2800- Better support of GNU Pth via --with-pth configure option.
2801
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002802- Python/C API now properly exposed to dynamically-loaded extension
2803 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002804
2805- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2806 Don't define MS_SYNC to be zero when it is undefined. Added missing
2807 prototypes in posixmodule.c.
2808
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002809- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002810 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002811
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002812- Fix largefile support on older NetBSD systems and OpenBSD by adding
2813 define for TELL64.
2814
2815
2816Tools and other miscellany
2817
2818- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2819
2820- freeze: The modulefinder now works with 2.0 opcodes.
2821
Tim Petersa3a3a032000-11-30 05:22:44 +00002822- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002823 Move hackery of sys.argv until after the Tk instance has been
2824 created, which allows the application-specific Tkinter
2825 initialization to be executed if present; also pass an explicit
2826 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002827
Jeremy Hylton1b618592000-09-26 05:32:36 +00002828
2829What's new in 2.0 beta 1?
2830=========================
2831
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002832Source Incompatibilities
2833------------------------
2834
2835None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2836such as single-argument append(), connect() and bind(), and changes to
2837str(long) and repr(float).
2838
2839
2840Binary Incompatibilities
2841------------------------
2842
2843- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2844with Python 2.0; these extensions will have to be rebuilt for Python
28452.0.
2846
2847- On Windows, attempting to import a third party extension built for
2848Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2849can do about this. Check your PYTHONPATH environment variable!
2850
2851- Python bytecode files (*.pyc and *.pyo) are not compatible between
2852releases.
2853
2854
2855Overview of Changes Since 1.6
2856-----------------------------
2857
2858There are many new modules (including brand new XML support through
2859the xml package, and i18n support through the gettext module); a list
2860of all new modules is included below. Lots of bugs have been fixed.
2861
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002862The process for making major new changes to the language has changed
2863since Python 1.6. Enhancements must now be documented by a Python
2864Enhancement Proposal (PEP) before they can be accepted.
2865
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002866There are several important syntax enhancements, described in more
2867detail below:
2868
2869 - Augmented assignment, e.g. x += 1
2870
2871 - List comprehensions, e.g. [x**2 for x in range(10)]
2872
2873 - Extended import statement, e.g. import Module as Name
2874
2875 - Extended print statement, e.g. print >> file, "Hello"
2876
2877Other important changes:
2878
2879 - Optional collection of cyclical garbage
2880
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002881Python Enhancement Proposal (PEP)
2882---------------------------------
2883
2884PEP stands for Python Enhancement Proposal. A PEP is a design
2885document providing information to the Python community, or describing
2886a new feature for Python. The PEP should provide a concise technical
2887specification of the feature and a rationale for the feature.
2888
2889We intend PEPs to be the primary mechanisms for proposing new
2890features, for collecting community input on an issue, and for
2891documenting the design decisions that have gone into Python. The PEP
2892author is responsible for building consensus within the community and
2893documenting dissenting opinions.
2894
2895The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002896
2897Augmented Assignment
2898--------------------
2899
2900This must have been the most-requested feature of the past years!
2901Eleven new assignment operators were added:
2902
Guido van Rossume905e952000-09-05 12:42:46 +00002903 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002904
2905For example,
2906
2907 A += B
2908
2909is similar to
2910
2911 A = A + B
2912
2913except that A is evaluated only once (relevant when A is something
2914like dict[index].attr).
2915
2916However, if A is a mutable object, A may be modified in place. Thus,
2917if A is a number or a string, A += B has the same effect as A = A+B
2918(except A is only evaluated once); but if a is a list, A += B has the
2919same effect as A.extend(B)!
2920
2921Classes and built-in object types can override the new operators in
2922order to implement the in-place behavior; the not-in-place behavior is
2923used automatically as a fallback when an object doesn't implement the
2924in-place behavior. For classes, the method name is derived from the
2925method name for the corresponding not-in-place operator by inserting
2926an 'i' in front of the name, e.g. __iadd__ implements in-place
2927__add__.
2928
2929Augmented assignment was implemented by Thomas Wouters.
2930
2931
2932List Comprehensions
2933-------------------
2934
2935This is a flexible new notation for lists whose elements are computed
2936from another list (or lists). The simplest form is:
2937
2938 [<expression> for <variable> in <sequence>]
2939
Guido van Rossum56db0952000-09-06 23:34:25 +00002940For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002941This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002942
2943You can also add a condition:
2944
2945 [<expression> for <variable> in <sequence> if <condition>]
2946
2947For example, [w for w in words if w == w.lower()] would yield the list
2948of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002949than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002950
2951You can also have nested for loops and more than one 'if' clause. For
2952example, here's a function that flattens a sequence of sequences::
2953
2954 def flatten(seq):
2955 return [x for subseq in seq for x in subseq]
2956
2957 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2958
2959This prints
2960
2961 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2962
2963List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002964Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002965
2966
2967Extended Import Statement
2968-------------------------
2969
2970Many people have asked for a way to import a module under a different
2971name. This can be accomplished like this:
2972
2973 import foo
2974 bar = foo
2975 del foo
2976
2977but this common idiom gets old quickly. A simple extension of the
2978import statement now allows this to be written as follows:
2979
2980 import foo as bar
2981
2982There's also a variant for 'from ... import':
2983
2984 from foo import bar as spam
2985
2986This also works with packages; e.g. you can write this:
2987
2988 import test.regrtest as regrtest
2989
2990Note that 'as' is not a new keyword -- it is recognized only in this
2991context (this is only possible because the syntax for the import
2992statement doesn't involve expressions).
2993
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002994Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002995
2996
2997Extended Print Statement
2998------------------------
2999
3000Easily the most controversial new feature, this extension to the print
3001statement adds an option to make the output go to a different file
3002than the default sys.stdout.
3003
3004For example, to write an error message to sys.stderr, you can now
3005write:
3006
3007 print >> sys.stderr, "Error: bad dog!"
3008
3009As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003010evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003011
3012 print >> None, "Hello world"
3013
3014is equivalent to
3015
3016 print "Hello world"
3017
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003018Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003019
3020
3021Optional Collection of Cyclical Garbage
3022---------------------------------------
3023
3024Python is now equipped with a garbage collector that can hunt down
3025cyclical references between Python objects. It's no replacement for
3026reference counting; in fact, it depends on the reference counts being
3027correct, and decides that a set of objects belong to a cycle if all
3028their reference counts can be accounted for from their references to
3029each other. This devious scheme was first proposed by Eric Tiedemann,
3030and brought to implementation by Neil Schemenauer.
3031
3032There's a module "gc" that lets you control some parameters of the
3033garbage collection. There's also an option to the configure script
3034that lets you enable or disable the garbage collection. In 2.0b1,
3035it's on by default, so that we (hopefully) can collect decent user
3036experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003037performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003038off by default in the final 2.0 release.
3039
3040
3041Smaller Changes
3042---------------
3043
3044A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3045map(None, seq1, seq2, ...) when the sequences have the same length;
3046i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3047the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003048zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003049
3050sys.version_info is a tuple (major, minor, micro, level, serial).
3051
3052Dictionaries have an odd new method, setdefault(key, default).
3053dict.setdefault(key, default) returns dict[key] if it exists; if not,
3054it sets dict[key] to default and returns that value. Thus:
3055
3056 dict.setdefault(key, []).append(item)
3057
3058does the same work as this common idiom:
3059
3060 if not dict.has_key(key):
3061 dict[key] = []
3062 dict[key].append(item)
3063
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003064There are two new variants of SyntaxError that are raised for
3065indentation-related errors: IndentationError and TabError.
3066
3067Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3068escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003069
3070The limits on the size of expressions and file in Python source code
3071have been raised from 2**16 to 2**32. Previous versions of Python
3072were limited because the maximum argument size the Python VM accepted
3073was 2**16. This limited the size of object constructor expressions,
3074e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3075limit was raised thanks to a patch by Charles Waldman that effectively
3076fixes the problem. It is now much more likely that you will be
3077limited by available memory than by an arbitrary limit in Python.
3078
3079The interpreter's maximum recursion depth can be modified by Python
3080programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3081limit is the maximum number of recursive calls that can be made by
3082Python code. The limit exists to prevent infinite recursion from
3083overflowing the C stack and causing a core dump. The default value is
30841000. The maximum safe value for a particular platform can be found
3085by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003086
3087New Modules and Packages
3088------------------------
3089
3090atexit - for registering functions to be called when Python exits.
3091
3092imputil - Greg Stein's alternative API for writing custom import
3093hooks.
3094
3095pyexpat - an interface to the Expat XML parser, contributed by Paul
3096Prescod.
3097
3098xml - a new package with XML support code organized (so far) in three
3099subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3100would fill a volume. There's a special feature whereby a
3101user-installed package named _xmlplus overrides the standard
3102xmlpackage; this is intended to give the XML SIG a hook to distribute
3103backwards-compatible updates to the standard xml package.
3104
3105webbrowser - a platform-independent API to launch a web browser.
3106
3107
Guido van Rossume905e952000-09-05 12:42:46 +00003108Changed Modules
3109---------------
3110
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003111array -- new methods for array objects: count, extend, index, pop, and
3112remove
3113
3114binascii -- new functions b2a_hex and a2b_hex that convert between
3115binary data and its hex representation
3116
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003117calendar -- Many new functions that support features including control
3118over which day of the week is the first day, returning strings instead
3119of printing them. Also new symbolic constants for days of week,
3120e.g. MONDAY, ..., SUNDAY.
3121
3122cgi -- FieldStorage objects have a getvalue method that works like a
3123dictionary's get method and returns the value attribute of the object.
3124
3125ConfigParser -- The parser object has new methods has_option,
3126remove_section, remove_option, set, and write. They allow the module
3127to be used for writing config files as well as reading them.
3128
3129ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003130optionally support the RFC 959 REST command.
3131
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003132gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003133
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003134httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3135the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003136
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003137locale -- implement getdefaultlocale for Win32 and Macintosh
3138
3139marshal -- no longer dumps core when marshaling deeply nested or
3140recursive data structures
3141
3142os -- new functions isatty, seteuid, setegid, setreuid, setregid
3143
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003144os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3145support under Unix.
3146
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003147os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003148
3149os.path -- fix semantics of os.path.commonprefix
3150
3151smtplib -- support for sending very long messages
3152
3153socket -- new function getfqdn()
3154
3155readline -- new functions to read, write and truncate history files.
3156The readline section of the library reference manual contains an
3157example.
3158
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003159select -- add interface to poll system call
3160
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003161shutil -- new copyfileobj function
3162
3163SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3164HTTP server.
3165
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003166Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003167
3168urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003169e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003170
3171whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003172
3173
3174Obsolete Modules
3175----------------
3176
3177None. However note that 1.6 made a whole slew of modules obsolete:
3178stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3179poly, zmod, strop, util, whatsound.
3180
3181
3182Changed, New, Obsolete Tools
3183----------------------------
3184
Tim Peters8b092332000-09-05 20:15:25 +00003185None.
Guido van Rossume905e952000-09-05 12:42:46 +00003186
3187
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003188C-level Changes
3189---------------
3190
3191Several cleanup jobs were carried out throughout the source code.
3192
3193All C code was converted to ANSI C; we got rid of all uses of the
3194Py_PROTO() macro, which makes the header files a lot more readable.
3195
3196Most of the portability hacks were moved to a new header file,
3197pyport.h; several other new header files were added and some old
3198header files were removed, in an attempt to create a more rational set
3199of header files. (Few of these ever need to be included explicitly;
3200they are all included by Python.h.)
3201
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003202Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003203and Win64, especially for the new Intel Itanium processor. Mick also
3204added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003205
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003206The C APIs to return an object's size have been update to consistently
3207use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3208previous versions, the abstract interfaces used PyXXX_Length and the
3209concrete interfaces used PyXXX_Size. The old names,
3210e.g. PyObject_Length, are still available for backwards compatibility
3211at the API level, but are deprecated.
3212
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003213The PyOS_CheckStack function has been implemented on Windows by
3214Fredrik Lundh. It prevents Python from failing with a stack overflow
3215on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003216
3217The GC changes resulted in creation of two new slots on object,
3218tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003219the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003220
3221The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003222C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003223
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003224PyErr_Format has been updated to automatically calculate the size of
3225the buffer needed to hold the formatted result string. This change
3226prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003227
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003228New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003229
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003230PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3231that are the same as their non-Ex counterparts except they take an
3232extra flag argument that tells them to close the file when done.
3233
3234XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003235
Tim Peters8b092332000-09-05 20:15:25 +00003236
3237Windows Changes
3238---------------
3239
3240New popen2/popen3/peopen4 in os module (see Changed Modules above).
3241
3242os.popen is much more usable on Windows 95 and 98. See Microsoft
3243Knowledge Base article Q150956. The Win9x workaround described there
3244is implemented by the new w9xpopen.exe helper in the root of your
3245Python installation. Note that Python uses this internally; it is not
3246a standalone program.
3247
3248Administrator privileges are no longer required to install Python
3249on Windows NT or Windows 2000. If you have administrator privileges,
3250Python's registry info will be written under HKEY_LOCAL_MACHINE.
3251Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003252under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003253uses of Python, but will prevent some advanced uses from working
3254(for example, running a Python script as an NT service, or possibly
3255from CGI).
3256
3257[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3258installer; instead, it installs the needed Tcl/Tk files directly in the
3259Python directory. If you already have a Tcl/Tk installation, this
3260wastes some disk space (about 4 Megs) but avoids problems with
3261conflicting Tcl/Tk installations, and makes it much easier for Python
3262to ensure that Tcl/Tk can find all its files.
3263
3264[This was new in 1.6] The Windows installer now installs by default in
3265\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3266
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003267
3268Updates to the changes between 1.5.2 and 1.6
3269--------------------------------------------
3270
3271The 1.6 NEWS file can't be changed after the release is done, so here
3272is some late-breaking news:
3273
3274New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3275and changes to getlocale() and setlocale().
3276
3277The new module is now enabled per default.
3278
3279It is not true that the encodings codecs cannot be used for normal
3280strings: the string.encode() (which is also present on 8-bit strings
3281!) allows using them for 8-bit strings too, e.g. to convert files from
3282cp1252 (Windows) to latin-1 or vice-versa.
3283
3284Japanese codecs are available from Tamito KAJIYAMA:
3285http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3286
3287
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003288======================================================================