blob: 15644b8b58cdf29f4f10bf0feb8bea5d3bdade23 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Marc-André Lemburge92e0a92002-02-09 11:28:43 +00009- The UTF-8 codec will now encode and decode Unicode surrogates
10 correctly and without raising exceptions for unpaired ones.
11
Neal Norwitz649b7592002-01-01 19:07:13 +000012- file.xreadlines() now raises a ValueError if the file is closed:
13 Previously, an xreadlines object was returned which would raise
14 a ValueError when the xreadlines.next() method was called.
15
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000016- posix.killpg has been added where available.
17
Tim Petersaf8446f2001-12-21 21:36:50 +000018Extension modules
19
Martin v. Löwis29001ff2002-03-01 10:47:37 +000020- pwd and grp return enhanced tuples now, with symbolic field names.
21
Martin v. Löwis99866332002-03-01 10:27:01 +000022- array.array is now a type object. A new format character
23 'u' indicates Py_UNICODE arrays. For those, .tounicode and
24 .fromunicode methods are available. Arrays now support __iadd__
25 and __imul__.
26
Neal Norwitze790eae2002-01-01 21:14:12 +000027- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000028 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
29 is called.
30
Tim Petersaf8446f2001-12-21 21:36:50 +000031Library
32
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000033- socket module: the SSL support was broken out of the main
34 _socket module C helper and placed into a new _ssl helper
35 which now gets imported by socket.py if available and working.
36
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000037- encodings package: added aliases for all supported IANA character
38 sets
39
Guido van Rossum606fe4e2001-12-28 20:57:14 +000040- ftplib: to safeguard the user's privacy, anonymous login will use
41 "anonymous@" as default password, rather than the real user and host
42 name.
43
Fred Drake36736122002-01-10 13:50:31 +000044- webbrowser: tightened up the command passed to os.system() so that
45 arbitrary shell code can't be executed because a bogus URL was
46 passed in.
47
Tim Peters11bd9942002-02-01 00:52:29 +000048- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000049 gettext.find an optional all argument. Translations will now fallback
50 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000051
Martin v. Löwis9668b932002-01-12 11:27:42 +000052- distutils bdist commands now offer a --skip-build option.
53
Tim Petersaf8446f2001-12-21 21:36:50 +000054Tools/Demos
55
56Build
57
58C API
59
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000060- The "u#" parser marker will now pass through Unicode object as-is
61 without going through the buffer API.
62
Martin v. Löwis7198a522002-01-01 19:59:11 +000063- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
64
Tim Peters10a3bb52001-12-25 19:07:38 +000065- An old #define of ANY as void has been removed from pyport.h. This
66 hasn't been used since Python's pre-ANSI days, and the #define has
67 been marked as obsolete since then. SF bug 495548 says it created
68 conflicts with other packages, so keeping it around wasn't harmless.
69
Tim Petersaf8446f2001-12-21 21:36:50 +000070- Because Python's magic number scheme broke on January 1st, we decided
71 to stop Python development. Thanks for all the fish!
72
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000073- Some of us don't like fish, so we changed Python's magic number
74 scheme to a new one. See Python/import.c for details.
75
Tim Petersaf8446f2001-12-21 21:36:50 +000076New platforms
77
Martin v. Löwisa6e97582002-01-01 18:41:33 +000078- GNU/Hurd is now supported.
79
Tim Petersaf8446f2001-12-21 21:36:50 +000080Tests
81
82Windows
83
Tim Petersab034fa2002-02-01 11:27:43 +000084- os.waitpid() is now implemented for Windows, and can be used to block
85 until a specified process exits. This is similar to, but not exactly
86 the same as, os.waitpid() on POSIX systems. If you're waiting for
87 a specific process whose pid was obtained from one of the spawn()
88 functions, the same Python os.waitpid() code works across platforms.
89 See the docs for details.
90
Tim Peters11bd9942002-02-01 00:52:29 +000091- New tempfile.TemporaryFile implementation for Windows: this doesn't
92 need a TemproraryFileWrapper wrapper anymore, and should be immune
93 to a nasty problem: before 2.3, if you got a temp file on Windows, it
94 got wrapped in an object whose close() method first closed the
95 underlying file, then deleted the file. This usually worked fine.
96 However, the spawn family of functions on Windows create (at a low C
97 level) the same set of open files in the spawned process Q as were
98 open in the spawning process P. If a temp file f was among them, then
99 doing f.close() in P first closed P's C-level file handle on f, but Q's
100 C-level file handle on f remained open, so the attempt in P to delete f
101 blew up with a "Permission denied" error (Windows doesn't allow
102 deleting open files). This was surprising, subtle, and difficult to
103 work around.
104
105- The os module now exports all the symbolic constants usable with the
106 low-level os.open() on Windows: the new constants in 2.3 are
107 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
108 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
109 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
110 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
111 (so specify both if you want both; note that neither is useful unless
112 specified with O_CREAT too).
113
Tim Petersaf8446f2001-12-21 21:36:50 +0000114Mac
115
116
Tim Peters909c0912001-12-14 23:16:18 +0000117What's New in Python 2.2 final?
118Release date: 21-Dec-2001
119===============================
120
121Type/class unification and new-style classes
122
Barry Warsaw52acb492001-12-21 20:04:22 +0000123- pickle.py, cPickle: allow pickling instances of new-style classes
124 with a custom metaclass.
125
Tim Peters909c0912001-12-14 23:16:18 +0000126Core and builtins
127
Barry Warsaw52acb492001-12-21 20:04:22 +0000128- weakref proxy object: when comparing, unwrap both arguments if both
129 are proxies.
130
Tim Peters909c0912001-12-14 23:16:18 +0000131Extension modules
132
Barry Warsaw52acb492001-12-21 20:04:22 +0000133- binascii.b2a_base64(): fix a potential buffer overrun when encoding
134 very short strings.
135
136- cPickle: the obscure "fast" mode was suspected of causing stack
137 overflows on the Mac. Hopefully fixed this by setting the recursion
138 limit much smaller. If the limit is too low (it only affects
139 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
140 when compiling cPickle.c (or in pyconfig.h).
141
Tim Peters909c0912001-12-14 23:16:18 +0000142Library
143
Barry Warsaw52acb492001-12-21 20:04:22 +0000144- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
145 close or delete time).
146
147- rfc822.py: fixed a bug where the address '<>' was converted to None
148 instead of an empty string (also fixes the email.Utils module).
149
150- xmlrpclib.py: version 1.0.0; uses precision for doubles.
151
152- test suite: the pickle and cPickle tests were not executing any code
153 when run from the standard regresssion test.
154
Tim Peters909c0912001-12-14 23:16:18 +0000155Tools/Demos
156
157Build
158
159C API
160
161New platforms
162
163Tests
164
165Windows
166
Barry Warsaw52acb492001-12-21 20:04:22 +0000167- distutils package: fixed broken Windows installers (bdist_wininst).
168
169- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
170 instances are deleted at process exit time.
171
172- socket.py: prevent mysterious warnings when socket instances are
173 deleted at process exit time.
174
175- posixmodule.c: fix a Windows crash with stat() of a filename ending
176 in backslash.
177
Tim Peters909c0912001-12-14 23:16:18 +0000178Mac
179
Barry Warsaw52acb492001-12-21 20:04:22 +0000180- The Carbon toolbox modules have been upgraded to Universal Headers
181 3.4, and experimental CoreGraphics and CarbonEvents modules have
182 been added. All only for framework-enabled MacOSX.
183
Tim Peters909c0912001-12-14 23:16:18 +0000184
Tim Peters6272dfd2001-12-13 19:34:00 +0000185What's New in Python 2.2c1?
186Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000187===========================
188
189Type/class unification and new-style classes
190
Barry Warsaw06557452001-12-14 20:47:12 +0000191- Guido's tutorial introduction to the new type/class features has
192 been extensively updated. See
193
194 http://www.python.org/2.2/descrintro.html
195
196 That remains the primary documentation in this area.
197
Guido van Rossum33bab012001-12-05 22:45:48 +0000198- Fixed a leak: instance variables declared with __slots__ were never
199 deleted!
200
Guido van Rossum4b800852001-12-03 00:54:52 +0000201- The "delete attribute" method of descriptor objects is called
202 __delete__, not __del__. In previous releases, it was mistakenly
203 called __del__, which created an unfortunate overloading condition
204 with finalizers. (The "get attribute" and "set attribute" methods
205 are still called __get__ and __set__, respectively.)
206
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000207- Some subtle issues with the super built-in were fixed:
208
209 (a) When super itself is subclassed, its __get__ method would still
210 return an instance of the base class (i.e., of super).
211
212 (b) super(C, C()).__class__ would return C rather than super. This
213 is confusing. To fix this, I decided to change the semantics of
214 super so that it only applies to code attributes, not to data
215 attributes. After all, overriding data attributes is not
216 supported anyway.
217
218 (c) The __get__ method didn't check whether the argument was an
219 instance of the type used in creation of the super instance.
220
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000221- Previously, hash() of an instance of a subclass of a mutable type
222 (list or dictionary) would return some value, rather than raising
223 TypeError. This has been fixed. Also, directly calling
224 dict.__hash__ and list.__hash__ now raises the same TypeError
225 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000226
Guido van Rossumd331cb52001-12-05 19:46:42 +0000227- New-style objects now support deleting their __dict__. This is for
228 all intents and purposes equivalent to assigning a brand new empty
229 dictionary, but saves space if the object is not used further.
230
Tim Petersb3c9af12001-11-17 00:21:57 +0000231Core and builtins
232
Tim Peters3caca232001-12-06 06:23:26 +0000233- -Qnew now works as documented in PEP 238: when -Qnew is passed on
234 the command line, all occurrences of "/" use true division instead
235 of classic division. See the PEP for details. Note that "all"
236 means all instances in library and 3rd-party modules, as well as in
237 your own code. As the PEP says, -Qnew is intended for use only in
238 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000239 Note that test_coercion.py in the standard Python test suite fails
240 under -Qnew; this is expected, and won't be repaired until true
241 division becomes the default (in the meantime, test_coercion is
242 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000243
Fred Drake6c01e252001-12-14 17:08:12 +0000244- complex() now only allows the first argument to be a string
245 argument, and raises TypeError if either the second arg is a string
246 or if the second arg is specified when the first is a string.
247
Tim Petersb3c9af12001-11-17 00:21:57 +0000248Extension modules
249
Martin v. Löwis560da622001-11-24 09:24:51 +0000250- gc.get_referents was renamed to gc.get_referrers.
251
Tim Petersb3c9af12001-11-17 00:21:57 +0000252Library
253
Tim Peters25059d32001-12-07 20:35:43 +0000254- Functions in the os.spawn() family now release the global interpreter
255 lock around calling the platform spawn. They should always have done
256 this, but did not before 2.2c1. Multithreaded programs calling
257 an os.spawn function with P_WAIT will no longer block all Python threads
258 until the spawned program completes. It's possible that some programs
259 relies on blocking, although more likely by accident than by design.
260
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000261- webbrowser defaults to netscape.exe on OS/2 now.
262
Martin v. Löwis652e1912001-11-25 14:50:56 +0000263- Tix.ResizeHandle exposes detach_widget, hide, and show.
264
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000265- The charset alias windows_1252 has been added.
266
Barry Warsaw06557452001-12-14 20:47:12 +0000267- types.StringTypes is a tuple containing the defined string types;
268 usually this will be (str, unicode), but if Python was compiled
269 without Unicode support it will be just (str,).
270
271- The pulldom and minidom modules were synchronized to PyXML.
272
Tim Petersb3c9af12001-11-17 00:21:57 +0000273Tools/Demos
274
Barry Warsaw06557452001-12-14 20:47:12 +0000275- A new script called Tools/scripts/google.py was added, which fires
276 off a search on Google.
277
Tim Petersb3c9af12001-11-17 00:21:57 +0000278Build
279
Barry Warsaw06557452001-12-14 20:47:12 +0000280- Note that release builds of Python should arrange to define the
281 preprocessor symbol NDEBUG on the command line (or equivalent).
282 In the 2.2 pre-release series we tried to define this by magic in
283 Python.h instead, but it proved to cause problems for extension
284 authors. The Unix, Windows and Mac builds now all define NDEBUG in
285 release builds via cmdline (or equivalent) instead. Ports to
286 other platforms should do likewise.
287
Jack Jansen1999ef42001-12-06 21:47:20 +0000288- It is no longer necessary to use --with-suffix when building on a
289 case-insensitive file system (such as Mac OS X HFS+). In the build
290 directory an extension is used, but not in the installed python.
291
Tim Petersb3c9af12001-11-17 00:21:57 +0000292C API
293
Tim Petersf582b822001-12-11 18:51:08 +0000294- New function PyDict_MergeFromSeq2() exposes the builtin dict
295 constructor's logic for updating a dictionary from an iterable object
296 producing key-value pairs.
297
Tim Peterscffed4b2001-11-29 03:26:37 +0000298- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000299 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000300 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
301 dump core in some bad cases. This has been repaired. As a result,
302 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
303 previously went unchallenged.
304
Tim Petersb3c9af12001-11-17 00:21:57 +0000305New platforms
306
307Tests
308
309Windows
310
311Mac
312
Jack Jansenffa260f2001-12-06 21:14:00 +0000313- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
314 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000315
Barry Warsaw06557452001-12-14 20:47:12 +0000316- Changed logic for finding python home in Mac OS X framework Pythons.
317 Now sys.executable points to the executable again, in stead of to
318 the shared library. The latter is used only for locating the python
319 home.
320
321
Tim Peters84362bc2001-10-19 17:55:30 +0000322What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000323Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000324===========================
325
326Type/class unification and new-style classes
327
Guido van Rossum3d27df02001-11-15 20:27:54 +0000328- Multiple inheritance mixing new-style and classic classes in the
329 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000330
331 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000332 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000333
334 The MRO (method resolution order) for each base class is respected
335 according to its kind, but the MRO for the derived class is computed
336 using new-style MRO rules if any base clase is a new-style class.
337 This needs to be documented.
338
Tim Petersa427a2b2001-10-29 22:25:45 +0000339- The new builtin dictionary() constructor, and dictionary type, have
340 been renamed to dict. This reflects a decade of common usage.
341
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000342- dict() now accepts an iterable object producing 2-sequences. For
343 example, dict(d.items()) == d for any dictionary d. The argument,
344 and the elements of the argument, can be any iterable objects.
345
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000346- New-style classes can now have a __del__ method, which is called
347 when the instance is deleted (just like for classic classes).
348
Guido van Rossum12d955c2001-10-26 14:56:06 +0000349- Assignment to object.__dict__ is now possible, for objects that are
350 instances of new-style classes that have a __dict__ (unless the base
351 class forbids it).
352
Guido van Rossumc8e56452001-10-22 00:43:43 +0000353- Methods of built-in types now properly check for keyword arguments
354 (formerly these were silently ignored). The only built-in methods
355 that take keyword arguments are __call__, __init__ and __new__.
356
Guido van Rossum86443212001-10-27 22:28:54 +0000357- The socket function has been converted to a type; see below.
358
Tim Peters84362bc2001-10-19 17:55:30 +0000359Core and builtins
360
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000361- Assignment to __debug__ raises SyntaxError at compile-time. This
362 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000363 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000364
Guido van Rossum12d955c2001-10-26 14:56:06 +0000365- Clarified the error messages for unsupported operands to an operator
366 (like 1 + '').
367
Tim Peters84362bc2001-10-19 17:55:30 +0000368Extension modules
369
Tim Peters5ebfd362001-11-13 23:11:19 +0000370- mmap has a new keyword argument, "access", allowing a uniform way for
371 both Windows and Unix users to create read-only, write-through and
372 copy-on-write memory mappings. This was previously possible only on
373 Unix. A new keyword argument was required to support this in a
374 uniform way because the mmap() signuatures had diverged across
375 platforms. Thanks to Jay T Miller for repairing this!
376
Tim Peters169ded02001-11-03 19:57:21 +0000377- By default, the gc.garbage list now contains only those instances in
378 unreachable cycles that have __del__ methods; in 2.1 it contained all
379 instances in unreachable cycles. "Instances" here has been generalized
380 to include instances of both new-style and old-style classes.
381
Guido van Rossum12d955c2001-10-26 14:56:06 +0000382- The socket module defines a new method for socket objects,
383 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000384 send() until all data has been sent. Also, the socket function has
385 been converted to a subclassable type, like list and tuple (etc.)
386 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000387
388- Various bugfixes to the curses module. There is now a test suite
389 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000390
Guido van Rossum692adf12001-10-30 03:03:03 +0000391- binascii.b2a_base64 no longer places an arbitrary restriction of 57
392 bytes on its input.
393
Tim Peters84362bc2001-10-19 17:55:30 +0000394Library
395
Tim Peters5ebfd362001-11-13 23:11:19 +0000396- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000397 convenience function.
398
Tim Peters75335872001-11-03 19:35:43 +0000399- Symbolic group names in regular expressions must be unique. For
400 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
401 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000402 Python 2.2 detects this error at regexp compilation time;
403 previously, the error went undetected, and results were
404 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
405 pattern.subn() methods have been rewritten in C. Also, an
406 experimental function/method finditer() has been added, which works
407 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000408
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000409- Tix exposes more commands through the classes DirSelectBox,
410 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
411 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
412 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
413
Tim Peters98791af2001-10-23 01:59:54 +0000414- Traceback objects are now scanned by cyclic garbage collection, so
415 cycles created by casual use of sys.exc_info() no longer cause
416 permanent memory leaks (provided garbage collection is enabled).
417
Guido van Rossum49192142001-10-24 20:51:44 +0000418- os.extsep -- a new variable needed by the RISCOS support. It is the
419 separator used by extensions, and is '.' on all platforms except
420 RISCOS, where it is '/'. There is no need to use this variable
421 unless you have a masochistic desire to port your code to RISCOS.
422
Barry Warsaw012852b2001-11-16 16:17:27 +0000423- mimetypes.py has optional support for non-standard, but commonly
424 found types. guess_type() and guess_extension() now accept an
425 optional `strict' flag, defaulting to true, which controls whether
426 recognize non-standard types or not. A few non-standard types we
427 know about have been added. Also, when run as a script, there are
428 new -l and -e options.
429
430- statcache is now deprecated.
431
432- email.Utils.formatdate() now produces the preferred RFC 2822 style
433 dates with numeric timezones (it used to produce obsolete dates
434 hard coded to "GMT" timezone). An optional `localtime' flag is
435 added to produce dates in the local timezone, with daylight savings
436 time properly taken into account.
437
438- In pickle and cPickle, instead of masking errors in load() by
439 transforming them into SystemError, we let the original exception
440 propagate out. Also, implement support for __safe_for_unpickling__
441 in pickle, as it already was supported in cPickle.
442
Tim Peters84362bc2001-10-19 17:55:30 +0000443Tools/Demos
444
445Build
446
Barry Warsaw012852b2001-11-16 16:17:27 +0000447- The dbm module is built using libdb1 if available. The bsddb module
448 is built with libdb3 if available.
449
450- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
451
Tim Peters84362bc2001-10-19 17:55:30 +0000452C API
453
Tim Peters1fc240e2001-10-26 05:06:50 +0000454- New function PySequence_Fast_GET_SIZE() returns the size of a non-
455 NULL result from PySequence_Fast(), more quickly than calling
456 PySequence_Size().
457
Barry Warsaw012852b2001-11-16 16:17:27 +0000458- New argument unpacking function PyArg_UnpackTuple() added.
459
460- New functions PyObject_CallFunctionObjArgs() and
461 PyObject_CallMethodObjArgs() have been added to make it more
462 convenient and efficient to call functions and methods from C.
463
464- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
465 possible that this will propagate errors it didn't before.
466
467- New function PyObject_CheckReadBuffer(), which returns true if its
468 argument supports the single-segment readable buffer interface.
469
Tim Peters84362bc2001-10-19 17:55:30 +0000470New platforms
471
Guido van Rossum86443212001-10-27 22:28:54 +0000472- We've finally confirmed that this release builds on HP-UX 11.00,
473 *with* threads, and passes the test suite.
474
Tim Peters7a33d8b2001-11-05 02:51:07 +0000475- Thanks to a series of patches from Michael Muller, Python may build
476 again under OS/2 Visual Age C++.
477
Guido van Rossum49192142001-10-24 20:51:44 +0000478- Updated RISCOS port by Dietmar Schwertberger.
479
Tim Peters84362bc2001-10-19 17:55:30 +0000480Tests
481
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000482- Added a test script for the curses module. It isn't run automatically;
483 regrtest.py must be run with '-u curses' to enable it.
484
Tim Peters84362bc2001-10-19 17:55:30 +0000485Windows
486
Barry Warsaw012852b2001-11-16 16:17:27 +0000487Mac
488
489- PythonScript has been moved to unsupported and is slated to be
490 removed completely in the next release.
491
492- It should now be possible to build applets that work on both OS9 and
493 OSX.
494
495- The core is now linked with CoreServices not Carbon; as a side
496 result, default 8bit encoding on OSX is now ASCII.
497
498- Python should now build on OSX 10.1.1
499
Tim Peters84362bc2001-10-19 17:55:30 +0000500
Tim Petersabf925f2001-09-28 21:53:42 +0000501What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000502Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000503===========================
504
505Type/class unification and new-style classes
506
Guido van Rossum687ae002001-10-15 22:03:32 +0000507- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000508 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000509 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000510 remains: the __dict__ of a new-style class is a read-only proxy; you
511 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000512 __defined__ attribute of new-style types no longer exists, for lack
513 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000514 future a __cache__ may be resurrected with a similar function, if I
515 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000516
Tim Peters1c9ca872001-10-04 06:43:12 +0000517- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
518 always returned None, even when there was a class docstring).
519
520- doctest now finds and runs docstrings attached to new-style classes,
521 class methods, static methods, and properties.
522
Guido van Rossum9074ef62001-10-16 21:34:49 +0000523Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000524
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000525- A very subtle syntactical pitfall in list comprehensions was fixed.
526 For example: [a+b for a in 'abc', for b in 'def']. The comma in
527 this example is a mistake. Previously, this would silently let 'a'
528 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
529 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
530 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
531 Note that [a for a in <singleton>] is a convoluted way to say
532 [<singleton>] anyway, so it's not like any expressiveness is lost.
533
Guido van Rossum9074ef62001-10-16 21:34:49 +0000534- getattr(obj, name, default) now only catches AttributeError, as
535 documented, rather than returning the default value for all
536 exceptions (which could mask bugs in a __getattr__ hook, for
537 example).
538
Fred Drakecb7a6b52001-10-22 18:41:51 +0000539- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000540 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000541 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000542 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000543
Guido van Rossum1c486092001-10-19 02:05:35 +0000544- unicode(obj) now behaves more like str(obj), accepting arbitrary
545 objects, and calling a __unicode__ method if it exists.
546 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000547 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000548
Barry Warsawf6fb1712001-10-19 05:35:40 +0000549- isinstance() now allows any object as the first argument and a
550 class, a type or something with a __bases__ tuple attribute for the
551 second argument. The second argument may also be a tuple of a
552 class, type, or something with __bases__, in which case isinstance()
553 will return true if the first argument is an instance of any of the
554 things contained in the second argument tuple. E.g.
555
556 isinstance(x, (A, B))
557
558 returns true if x is an instance of A or B.
559
Guido van Rossum9074ef62001-10-16 21:34:49 +0000560Extension modules
561
562- thread.start_new_thread() now returns the thread ID (previously None).
563
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000564- binascii has now two quopri support functions, a2b_qp and b2a_qp.
565
Guido van Rossumc524d952001-10-19 01:31:59 +0000566- readline now supports setting the startup_hook and the
567 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000568
Guido van Rossumc524d952001-10-19 01:31:59 +0000569- os and posix supports chroot(), setgroups() and unsetenv() where
570 available. The stat(), fstat(), statvfs() and fstatvfs() functions
571 now return "pseudo-sequences" -- the various fields can now be
572 accessed as attributes (e.g. os.stat("/").st_mtime) but for
573 backwards compatibility they also behave as a fixed-length sequence.
574 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000575 attributes.
576
577- time: localtime(), gmtime() and strptime() now return a
578 pseudo-sequence similar to the os.stat() return value, with
579 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000580
Guido van Rossum9074ef62001-10-16 21:34:49 +0000581- Decompression objects in the zlib module now accept an optional
582 second parameter to decompress() that specifies the maximum amount
583 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000584
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000585- optional SSL support in the socket module now exports OpenSSL
586 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
587 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000588 automatically seed its PRNG. Also, the keyfile and certfile
589 arguments to socket.ssl() are now optional.
590
591- posixmodule (and by extension, the os module on POSIX platforms) now
592 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000593
Guido van Rossum9074ef62001-10-16 21:34:49 +0000594Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000595
Tim Peters7402f792001-10-02 03:53:41 +0000596- doctest now excludes functions and classes not defined by the module
597 being tested, thanks to Tim Hochberg.
598
Fred Drakecb7a6b52001-10-22 18:41:51 +0000599- HotShot, a new profiler implemented using a C-based callback, has
600 been added. This substantially reduces the overhead of profiling,
601 but it is still quite preliminary. Support modules and
602 documentation will be added in upcoming releases (before 2.2 final).
603
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000604- profile now produces correct output in situations where an exception
605 raised in Python is cleared by C code (e.g. hasattr()). This used
606 to cause wrong output, including spurious claims of recursive
607 functions and attribution of time spent to the wrong function.
608
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000609 The code and documentation for the derived OldProfile and HotProfile
610 profiling classes was removed. The code hasn't worked for years (if
611 you tried to use them, they raised exceptions). OldProfile
612 intended to reproduce the behavior of the profiler Python used more
613 than 7 years ago, and isn't interesting anymore. HotProfile intended
614 to provide a faster profiler (but producing less information), and
615 that's a worthy goal we intend to meet via a different approach (but
616 without losing information).
617
Tim Peterscce092d2001-10-09 05:31:56 +0000618- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000619 a much better system-specific calibration constant. The constant can
620 now be specified in an instance constructor, or as a Profile class or
621 instance variable, instead of by editing profile.py's source code.
622 Calibration must still be done manually (see the docs for the profile
623 module).
624
625 Note that Profile.calibrate() must be overriden by subclasses.
626 Improving the accuracy required exploiting detailed knowledge of
627 profiler internals; the earlier method abstracted away the details
628 and measured a simplified model instead, but consequently computed
629 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000630
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000631- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000632 which indicates whether output is intended for the header 'Q'
633 encoding.
634
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000635- The SocketServer.ThreadingMixIn class now closes the request after
636 finish_request() returns. (Not when it errors out though.)
637
Barry Warsawf6fb1712001-10-19 05:35:40 +0000638- The nntplib module's NNTP.body() method has grown a `file' argument
639 to allow saving the message body to a file.
640
641- The email package has added a class email.Parser.HeaderParser which
642 only parses headers and does not recurse into the message's body.
643 Also, the module/class MIMEAudio has been added for representing
644 audio data (contributed by Anthony Baxter).
645
646- ftplib should be able to handle files > 2GB.
647
648- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
649 ON, and OFF.
650
Fred Drakecb7a6b52001-10-22 18:41:51 +0000651- xml.dom.minidom NodeList objects now support the length attribute
652 and item() method as required by the DOM specifications.
653
Guido van Rossumed554f62001-10-02 23:15:37 +0000654Tools/Demos
655
656- Demo/dns was removed. It no longer serves any purpose; a package
657 derived from it is now maintained by Anthony Baxter, see
658 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000659
Barry Warsawf6fb1712001-10-19 05:35:40 +0000660- The freeze tool has been made more robust, and two new options have
661 been added: -X and -E.
662
Tim Petersabf925f2001-09-28 21:53:42 +0000663Build
664
Barry Warsawf6fb1712001-10-19 05:35:40 +0000665- configure will use CXX in LINKCC if CXX is used to build main() and
666 the system requires to link a C++ main using the C++ compiler.
667
Tim Petersabf925f2001-09-28 21:53:42 +0000668C API
669
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000670- The documentation for the tp_compare slot is updated to require that
671 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
672 not correct. This is not yet enforced but will be enforced in
673 Python 2.3; even later, we may use -2 to indicate errors and +2 for
674 "NotImplemented". Right now, -1 should be used for an error return.
675
Tim Petersd38b1c72001-09-30 05:09:37 +0000676- PyLong_AsLongLong() now accepts int (as well as long) arguments.
677 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
678 as long) arguments.
679
Guido van Rossum3c288632001-10-16 21:13:49 +0000680- PyThread_start_new_thread() now returns a long int giving the thread
681 ID, if one can be calculated; it returns -1 for error, 0 if no
682 thread ID is calculated (this is an incompatible change, but only
683 the thread module used this API). This code has only really been
684 tested on Linux and Windows; other platforms please beware (and
685 report any bugs or strange behavior).
686
Guido van Rossum1c486092001-10-19 02:05:35 +0000687- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
688 input.
689
Tim Petersabf925f2001-09-28 21:53:42 +0000690New platforms
691
692Tests
693
694Windows
695
Tim Peters04cf1d32001-10-09 22:39:40 +0000696- Installer: If you install IDLE, and don't disable file-extension
697 registration, a new "Edit with IDLE" context (right-click) menu entry
698 is created for .py and .pyw files.
699
Tim Peters1ce3cf72001-10-01 17:58:40 +0000700- The signal module now supports SIGBREAK on Windows, thanks to Steven
701 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
702 action remains to call Win32 ExitProcess(). This can be changed via
703 signal.signal(). For example:
704
705 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
706 # (SIGINT) behavior.
707 import signal
708 signal.signal(signal.SIGBREAK,
709 signal.default_int_handler)
710
711 try:
712 while 1:
713 pass
714 except KeyboardInterrupt:
715 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
716 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
717 # program without the possibility for any Python-level cleanup).
718 print "Clean exit"
719
Tim Petersabf925f2001-09-28 21:53:42 +0000720
Tim Petersb07352e2001-09-08 01:25:47 +0000721What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000722Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000723===========================
724
Guido van Rossum808eea72001-09-25 04:15:41 +0000725Type/class unification and new-style classes
726
727- pydoc and inspect are now aware of new-style classes;
728 e.g. help(list) at the interactive prompt now shows proper
729 documentation for all operations on list objects.
730
731- Applications using Jim Fulton's ExtensionClass module can now safely
732 be used with Python 2.2. In particular, Zope 2.4.1 now works with
733 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
734 examples also work again. It is hoped that Gtk and Boost also work
735 with 2.2a4 and beyond. (If you can confirm this, please write
736 webmaster@python.org; if there are still problems, please open a bug
737 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000738
Tim Peters66c1a522001-09-24 21:17:50 +0000739- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
740 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
741 in the constructed property object. fget, fset and fdel weren't
742 discoverable from Python in 2.2a3. __doc__ is new, and allows to
743 associate a docstring with a property.
744
Guido van Rossum808eea72001-09-25 04:15:41 +0000745- Comparison overloading is now more completely implemented. For
746 example, a str subclass instance can properly be compared to a str
747 instance, and it can properly overload comparison. Ditto for most
748 other built-in object types.
749
750- The repr() of new-style classes has changed; instead of <type
751 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
752 *except* for built-in types, which are still rendered as <type
753 'Foo'> (to avoid upsetting existing code that might parse or
754 otherwise rely on repr() of certain type objects).
755
756- The repr() of new-style objects is now always <Foo object at XXX>;
757 previously, it was sometimes <Foo instance at XXX>.
758
759- For new-style classes, what was previously called __getattr__ is now
760 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000761 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000762 one in classic classes is defined which is called only if regular
763 attribute access raises AttributeError; to catch *all* attribute
764 access, you can use __getattribute__ (for new-style classes). If
765 both are defined, __getattribute__ is called first, and if it raises
766 AttributeError, __getattr__ is called.
767
768- The __class__ attribute of new-style objects can be assigned to.
769 The new class must have the same C-level object layout as the old
770 class.
771
772- The builtin file type can be subclassed now. In the usual pattern,
773 "file" is the name of the builtin type, and file() is a new builtin
774 constructor, with the same signature as the builtin open() function.
775 file() is now the preferred way to open a file.
776
777- Previously, __new__ would only see sequential arguments passed to
778 the type in a constructor call; __init__ would see both sequential
779 and keyword arguments. This made no sense whatsoever any more, so
780 now both __new__ and __init__ see all arguments.
781
782- Previously, hash() applied to an instance of a subclass of str or
783 unicode always returned 0. This has been repaired.
784
785- Previously, an operation on an instance of a subclass of an
786 immutable type (int, long, float, complex, tuple, str, unicode),
787 where the subtype didn't override the operation (and so the
788 operation was handled by the builtin type), could return that
789 instance instead a value of the base type. For example, if s was of
790 a str sublass type, s[:] returned s as-is. Now it returns a str
791 with the same value as s.
792
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000793- Provisional support for pickling new-style objects has been added.
794
Guido van Rossum808eea72001-09-25 04:15:41 +0000795Core
796
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000797- file.writelines() now accepts any iterable object producing strings.
798
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000799- PyUnicode_FromEncodedObject() now works very much like
800 PyObject_Str(obj) in that it tries to use __str__/tp_str
801 on the object if the object is not a string or buffer. This
802 makes unicode() behave like str() when applied to non-string/buffer
803 objects.
804
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000805- PyFile_WriteObject now passes Unicode objects to the file's write
806 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000807 of a print statement must support Unicode objects, i.e. they must
808 at least convert them into ASCII strings.
809
Guido van Rossum624c8af2001-09-18 15:21:04 +0000810- Thread scheduling on Solaris should be improved; it is no longer
811 necessary to insert a small sleep at the start of a thread in order
812 to let other runnable threads be scheduled.
813
Tim Petersb07352e2001-09-08 01:25:47 +0000814Library
815
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000816- StringIO.StringIO instances and cStringIO.StringIO instances support
817 read character buffer compatible objects for their .write() methods.
818 These objects are converted to strings and then handled as such
819 by the instances.
820
Barry Warsaw2f600732001-09-24 04:28:10 +0000821- The "email" package has been added. This is basically a port of the
822 mimelib package <http://sf.net/projects/mimelib> with API changes
823 and some implementations updated to use iterators and generators.
824
Tim Peters8a9c2842001-09-22 21:30:22 +0000825- difflib.ndiff() and difflib.Differ.compare() are generators now. This
826 restores the ability of Tools/scripts/ndiff.py to start producing output
827 before the entire comparison is complete.
828
Barry Warsaw58b072d2001-09-22 04:44:21 +0000829- StringIO.StringIO instances and cStringIO.StringIO instances support
830 iteration just like file objects (i.e. their .readline() method is
831 called for each iteration until it returns an empty string).
832
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000833- The codecs module has grown four new helper APIs to access
834 builtin codecs: getencoder(), getdecoder(), getreader(),
835 getwriter().
836
Guido van Rossum624c8af2001-09-18 15:21:04 +0000837- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
838 simplifies writing XML RPC servers.
839
Barry Warsaw647d5e82001-09-28 17:01:02 +0000840- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000841 after interpretation of symbolic links. On non-Unix systems, this
842 is an alias for os.path.abspath().
843
Tim Peters16a77ad2001-09-08 04:00:12 +0000844- operator.indexOf() (PySequence_Index() in the C API) now works with any
845 iterable object.
846
Guido van Rossum624c8af2001-09-18 15:21:04 +0000847- smtplib now supports various authentication and security features of
848 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000849
Guido van Rossum624c8af2001-09-18 15:21:04 +0000850- hmac: a new module implementing keyed hashing for message
851 authentication.
852
853- mimetypes now recognizes more extensions and file types. At the
854 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000855
Guido van Rossum624c8af2001-09-18 15:21:04 +0000856- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000857 Python 2.2 bytecode generation. It has also been promoted from a
858 Tool to a standard library package. (Tools/compiler still exists as
859 a sample driver.)
860
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000861Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000862
Tim Petersb07352e2001-09-08 01:25:47 +0000863Build
864
Guido van Rossum624c8af2001-09-18 15:21:04 +0000865- Large file support (LFS) is now automatic when the platform supports
866 it; no more manual configuration tweaks are needed. On Linux, at
867 least, it's possible to have a system whose C library supports large
868 files but whose kernel doesn't; in this case, large file support is
869 still enabled but doesn't do you any good unless you upgrade your
870 kernel or share your Python executable with another system whose
871 kernel has large file support.
872
873- The configure script now supplies plausible defaults in a
874 cross-compilation environment. This doesn't mean that the supplied
875 values are always correct, or that cross-compilation now works
876 flawlessly -- but it's a first step (and it shuts up most of
877 autoconf's warnings about AC_TRY_RUN).
878
879- The Unix build is now a bit less chatty, courtesy of the parser
880 generator. The build is completely silent (except for errors) when
881 using "make -s", thanks to a -q option to setup.py.
882
Tim Petersb07352e2001-09-08 01:25:47 +0000883C API
884
Guido van Rossum624c8af2001-09-18 15:21:04 +0000885- The "structmember" API now supports some new flag bits to deny read
886 and/or write access to attributes in restricted execution mode.
887
Tim Petersb07352e2001-09-08 01:25:47 +0000888New platforms
889
Guido van Rossum624c8af2001-09-18 15:21:04 +0000890- Compaq's iPAQ handheld, running the "familiar" Linux distribution
891 (http://familiar.handhelds.org).
892
Tim Petersb07352e2001-09-08 01:25:47 +0000893Tests
894
Tim Peters8a9c2842001-09-22 21:30:22 +0000895- The "classic" standard tests, which work by comparing stdout to
896 an expected-output file under Lib/test/output/, no longer stop at
897 the first mismatch. Instead the test is run to completion, and a
898 variant of ndiff-style comparison is used to report all differences.
899 This is much easier to understand than the previous style of reporting.
900
901- The unittest-based standard tests now use regrtest's test_main()
902 convention, instead of running as a side-effect of merely being
903 imported. This allows these tests to be run in more natural and
904 flexible ways as unittests, outside the regrtest framework.
905
906- regrtest.py is much better integrated with unittest and doctest now,
907 especially in regard to reporting errors.
908
Tim Petersb07352e2001-09-08 01:25:47 +0000909Windows
910
Guido van Rossum624c8af2001-09-18 15:21:04 +0000911- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000912 that support it (NTFS under Windows 2000). See "What's New in
913 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000914
Tim Petersb07352e2001-09-08 01:25:47 +0000915
Tim Petersedc99312001-08-22 21:36:50 +0000916What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000917Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000918===========================
919
920Core
921
Tim Peters9fffa3e2001-09-04 05:14:19 +0000922- Conversion of long to float now raises OverflowError if the long is too
923 big to represent as a C double.
924
Tim Peters32f453e2001-09-03 08:35:41 +0000925- The 3-argument builtin pow() no longer allows a third non-None argument
926 if either of the first two arguments is a float, or if both are of
927 integer types and the second argument is negative (in which latter case
928 the arguments are converted to float, so this is really the same
929 restriction).
930
Tim Peters5d2b77c2001-09-03 05:47:38 +0000931- The builtin dir() now returns more information, and sometimes much
932 more, generally naming all attributes of an object, and all attributes
933 reachable from the object via its class, and from its class's base
934 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
935 an empty list. In 2.2a3,
936
937 >>> dir([])
938 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
939 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
940 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
941 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
942 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
943 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
944 'reverse', 'sort']
945
946 dir(module) continues to return only the module's attributes, though.
947
Tim Petersbdee63f2001-09-02 03:40:59 +0000948- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000949 than raising OverflowError. This is a partial implementation of PEP
950 237. You can use -Wdefault::OverflowWarning to enable a warning for
951 this situation, and -Werror::OverflowWarning to revert to the old
952 OverflowError exception.
953
Guido van Rossum61c345f2001-09-04 03:26:15 +0000954- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000955 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000956 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
957 -Qold, meaning the / operator has its classic meaning and no
958 warnings are issued. Using -Qwarn issues a run-time warning about
959 all uses of classic division for int and long arguments; -Qwarnall
960 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000961 (for use with fixdiv.py).
962 [Note: the remainder of this paragraph (preserved below) became
963 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
964 <obsolete>
965 Using -Qnew is questionable; it turns on new division by default, but
966 only in the __main__ module. You can usefully combine -Qwarn or
967 -Qwarnall and -Qnew: this gives the __main__ module new division, and
968 warns about classic division everywhere else.
969 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000970
Tim Petersbdee63f2001-09-02 03:40:59 +0000971- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000972 long, float, str, unicode, and tuple. (The types complex, list and
973 dictionary can also be subclassed; this was introduced earlier.)
974 Note that restrictions apply when subclassing immutable built-in
975 types: you can only affect the value of the instance by overloading
976 __new__. You can add mutable attributes, and the subclass instances
977 will have a __dict__ attribute, but you cannot change the "value"
978 (as implemented by the base class) of an immutable subclass instance
979 once it is created.
980
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000981- The dictionary constructor now takes an optional argument, a
982 mapping-like object, and initializes the dictionary from its
983 (key, value) pairs.
984
Tim Petersbdee63f2001-09-02 03:40:59 +0000985- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000986 "cooperative super calls" in a multiple inheritance setting. For an
987 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
988
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000989- A new built-in type, property, has been added. This enables the
990 creation of "properties". These are attributes implemented by
991 getter and setter functions (or only one of these for read-only or
992 write-only attributes), without the need to override __getattr__.
993 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000994
Tim Petersbdee63f2001-09-02 03:40:59 +0000995- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000996 liberalized, to allow leading zeroes. Examples of literals now
997 legal that were SyntaxErrors before:
998
999 00.0 0e3 0100j 07.5 00000000000000000008.
1000
Tim Petersbdee63f2001-09-02 03:40:59 +00001001- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001002 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1003
Tim Petersedc99312001-08-22 21:36:50 +00001004Library
1005
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001006- telnetlib includes symbolic names for the options, and support for
1007 setting an option negotiation callback.
1008
Tim Petersa40c7932001-09-05 22:36:56 +00001009- The new C standard no longer requires that math libraries set errno to
1010 ERANGE on overflow. For platform libraries that exploit this new
1011 freedom, Python's overflow-checking was wholly broken. A new overflow-
1012 checking scheme attempts to repair that, but may not be reliable on all
1013 platforms (C doesn't seem to provide anything both useful and portable
1014 in this area anymore).
1015
Martin v. Löwis44f86962001-09-05 13:44:54 +00001016- Asynchronous timeout actions are available through the new class
1017 threading.Timer.
1018
Tim Peters78526162001-09-05 00:53:45 +00001019- math.log and math.log10 now return sensible results for even huge
1020 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1021
Tim Petersbdee63f2001-09-02 03:40:59 +00001022- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001023 currently held. See the docs for the imp module.
1024
Tim Petersbdee63f2001-09-02 03:40:59 +00001025- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001026 dumps containing ints written on platforms where Python ints are 8 bytes.
1027 When read on a box where Python ints are 4 bytes, such values are
1028 converted to Python longs.
1029
Tim Petersbdee63f2001-09-02 03:40:59 +00001030- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001031 code objects is no longer allowed. This plugs a security hole.
1032
Steve Purcell6091cd62001-09-06 16:05:17 +00001033- unittest.TestResult instances no longer store references to tracebacks
1034 generated by test failures. This prevents unexpected dangling references
1035 to objects that should be garbage collected between tests.
1036
Tim Petersedc99312001-08-22 21:36:50 +00001037Tools
1038
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001039- Tools/scripts/fixdiv.py has been added which can be used to fix
1040 division operators as per PEP 238.
1041
Tim Petersedc99312001-08-22 21:36:50 +00001042Build
1043
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001044- If you are an adventurous person using Mac OS X you may want to look at
1045 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1046 application, which can be used for experimenting with Carbon or Cocoa.
1047 Discussion of this on pythonmac-sig, please.
1048
Tim Peters7eea37e2001-09-04 22:08:56 +00001049C API
1050
1051- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001052
Tim Peters9fffa3e2001-09-04 05:14:19 +00001053- Note that PyLong_AsDouble can fail! This has always been true, but no
1054 callers checked for it. It's more likely to fail now, because overflow
1055 errors are properly detected now. The proper way to check:
1056
1057 double x = PyLong_AsDouble(some_long_object);
1058 if (x == -1.0 && PyErr_Occurred()) {
1059 /* The conversion failed. */
1060 }
1061
Tim Petersbdee63f2001-09-02 03:40:59 +00001062- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001063 compile but will not participate in GC. To upgrade an extension
1064 module:
1065
1066 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001067
Neil Schemenauer4042c692001-08-30 15:38:01 +00001068 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1069 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001070
Neil Schemenauer4042c692001-08-30 15:38:01 +00001071 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1072 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001073
Neil Schemenauer4042c692001-08-30 15:38:01 +00001074 - remove PyGC_HEAD_SIZE from object size calculations
1075
1076 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1077
Tim Petersbdee63f2001-09-02 03:40:59 +00001078- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001079 These can be used safely to construct string objects from a
1080 sprintf-style format string (similar to the format string supported
1081 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001082
Tim Petersedc99312001-08-22 21:36:50 +00001083New platforms
1084
Tim Petersb7da0902001-09-02 23:01:43 +00001085- Stephen Hansen contributed patches sufficient to get a clean compile
1086 under Borland C (Windows), but he reports problems running it and ran
1087 out of time to complete the port. Volunteers? Expect a MemoryError
1088 when importing the types module; this is probably shallow, and
1089 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001090
Tim Petersedc99312001-08-22 21:36:50 +00001091Tests
1092
1093Windows
1094
Tim Peters6e13a562001-09-06 00:32:15 +00001095- Large file support is now enabled on Win32 platforms as well as on
1096 Win64. This means that, for example, you can use f.tell() and f.seek()
1097 to manipulate files larger than 2 gigabytes (provided you have enough
1098 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001099 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1100 filesize limit, and large file support makes no difference there.
1101 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1102 NTFS has no practical limit on file size, and files of any size can be
1103 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001104
Tim Petersbdee63f2001-09-02 03:40:59 +00001105- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001106 points to command.com (patch from Brian Quinlan).
1107
Tim Petersedc99312001-08-22 21:36:50 +00001108
Tim Peters20f51a72001-07-21 02:31:40 +00001109What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001110Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001111===========================
1112
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001113Build
1114
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001115- Tim Peters developed a brand new Windows installer using Wise 8.1,
1116 generously donated to us by Wise Solutions.
1117
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001118- configure supports a new option --enable-unicode, with the values
1119 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1120 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001121
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001122- A new configure option --enable-framework builds a Mac OS X framework,
1123 which "make frameworkinstall" will install. This provides a starting
1124 point for more mac-like functionality, join pythonmac-sig@python.org
1125 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001126
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001127- The NeXT platform is no longer supported.
1128
1129- The `new' module is now statically linked.
1130
Tim Peters0afb6092001-08-15 06:06:44 +00001131Tools
1132
1133- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001134 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001135 the module docstring for details.
1136
Tim Peters20f51a72001-07-21 02:31:40 +00001137Tests
1138
Tim Peters5e824c32001-08-12 22:25:01 +00001139- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001140 platforms, allowing to give clearer test result output. regrtest
1141 also has optional --use/-u switch to run normally disabled tests
1142 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001143
Tim Peters20f51a72001-07-21 02:31:40 +00001144- Several new tests in the standard test suite, with special thanks to
1145 Nick Mathewson.
1146
1147Core
1148
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001149- The floor division operator // has been added as outlined in PEP
1150 238. The / operator still provides classic division (and will until
1151 Python 3.0) unless "from __future__ import division" is included, in
1152 which case the / operator will provide true division. The operator
1153 module provides truediv() and floordiv() functions. Augmented
1154 assignment variants are included, as are the equivalent overloadable
1155 methods and C API methods. See the PEP for a full discussion:
1156 <http://python.sf.net/peps/pep-0238.html>
1157
Tim Peters6cd6a822001-08-17 22:11:27 +00001158- Future statements are now effective in simulated interactive shells
1159 (like IDLE). This should "just work" by magic, but read Michael
1160 Hudson's "Future statements in simulated shells" PEP 264 for full
1161 details: <http://python.sf.net/peps/pep-0264.html>.
1162
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001163- The type/class unification (PEP 252-253) was integrated into the
1164 trunk and is not so tentative any more (the exact specification of
1165 some features is still tentative). A lot of work has done on fixing
1166 bugs and adding robustness and features (performance still has to
1167 come a long way).
1168
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001169- Warnings about a mismatch in the Python API during extension import
1170 now use the Python warning framework (which makes it possible to
1171 write filters for these warnings).
1172
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001173- A function's __dict__ (aka func_dict) will now always be a
1174 dictionary. It used to be possible to delete it or set it to None,
1175 but now both actions raise TypeErrors. It is still legal to set it
1176 to a dictionary object. Getting func.__dict__ before any attributes
1177 have been assigned now returns an empty dictionary instead of None.
1178
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001179- A new command line option, -E, was added which disables the use of
1180 all environment variables, or at least those that are specifically
1181 significant to Python. Usually those have a name starting with
1182 "PYTHON". This was used to fix a problem where the tests fail if
1183 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1184 older distribution.
1185
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001186Library
1187
Tim Peters5e824c32001-08-12 22:25:01 +00001188- New class Differ and new functions ndiff() and restore() in difflib.py.
1189 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001190 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001191
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001192- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1193 value using the minimal quoting required for the value; more
1194 reliable than using xml.sax.saxutils.escape() for attribute values.
1195
1196- Readline completion support for cmd.Cmd was added.
1197
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001198- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1199
1200- Added function threading.BoundedSemaphore()
1201
1202- Added Ka-Ping Yee's cgitb.py module.
1203
1204- The `new' module now exposes the CO_xxx flags.
1205
Martin v. Löwis560da622001-11-24 09:24:51 +00001206- The gc module offers the get_referents function.
1207
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001208New platforms
1209
1210C API
1211
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001212- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1213 which provide a cross-platform implementations for the
1214 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1215 the standard sprintf() and vsprintf() C lib APIs, these versions
1216 apply bounds checking on the used buffer which enhances protection
1217 against buffer overruns.
1218
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001219- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001220 and extensions using different Unicode widths is rendered next to
1221 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001222 will result in an ImportError. Unicode extensions writers must make
1223 sure to check the Unicode width compatibility in their extensions by
1224 using at least one of the mangled Unicode APIs in the extension.
1225
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001226- Two new flags METH_NOARGS and METH_O are available in method definition
1227 tables to simplify implementation of methods with no arguments and a
1228 single untyped argument. Calling such methods is more efficient than
1229 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1230 deprecated.
1231
Tim Petersc1731372001-08-04 08:12:36 +00001232Windows
1233
1234- "import module" now compiles module.pyw if it exists and nothing else
1235 relevant is found.
1236
Tim Peters20f51a72001-07-21 02:31:40 +00001237
Guido van Rossum55a78992001-07-17 17:22:32 +00001238What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001239Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001240===========================
1241
1242Core
Tim Petersa814db52001-05-14 07:05:58 +00001243
Tim Peters6d6c1a32001-08-02 04:15:00 +00001244- TENTATIVELY, a large amount of code implementing much of what's
1245 described in PEP 252 (Making Types Look More Like Classes) and PEP
1246 253 (Subtyping Built-in Types) was added. This will be released
1247 with Python 2.2a1. Documentation will be provided separately
1248 through http://www.python.org/2.2/. The purpose of releasing this
1249 with Python 2.2a1 is to test backwards compatibility. It is
1250 possible, though not likely, that a decision is made not to release
1251 this code as part of 2.2 final, if any serious backwards
1252 incompapatibilities are found during alpha testing that cannot be
1253 repaired.
1254
Guido van Rossum55a78992001-07-17 17:22:32 +00001255- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001256 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001257 more 'yield' statements. See PEP 255. Since this adds a new
1258 keyword to the language, this feature must be enabled by including a
1259 future statement: "from __future__ import generators" (see PEP 236).
1260 Generators will become a standard feature in a future release
1261 (probably 2.3). Without this future statement, 'yield' remains an
1262 ordinary identifier, but a warning is issued each time it is used.
1263 (These warnings currently don't conform to the warnings framework of
1264 PEP 230; we intend to fix this in 2.2a2.)
1265
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001266- The UTF-16 codec was modified to be more RFC compliant. It will now
1267 only remove BOM characters at the start of the string and then
1268 only if running in native mode (UTF-16-LE and -BE won't remove a
1269 leading BMO character).
1270
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001271- Strings now have a new method .decode() to complement the already
1272 existing .encode() method. These two methods provide direct access
1273 to the corresponding decoders and encoders of the registered codecs.
1274
1275 To enhance the usability of the .encode() method, the special
1276 casing of Unicode object return values was dropped (Unicode objects
1277 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001278
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001279 Both methods will now return whatever the codec in charge of the
1280 requested encoding returns as object, e.g. Unicode codecs will
1281 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1282 will return u"äöü"). This enables codec writer to create codecs
1283 for various simple to use conversions.
1284
1285 New codecs were added to demonstrate these new features (the .encode()
1286 and .decode() columns indicate the type of the returned objects):
1287
1288 Name | .encode() | .decode() | Description
1289 ----------------------------------------------------------------------
1290 uu | string | string | UU codec (e.g. for email)
1291 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001292 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001293 zlib | string | string | zlib compression
1294 hex | string | string | 2-byte hex codec
1295 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1296
Mark Hammond2a0af792001-05-14 03:09:36 +00001297- Some operating systems now support the concept of a default Unicode
1298 encoding for file system operations. Notably, Windows supports 'mbcs'
1299 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001300 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001301 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001302
1303 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001304 functions that return filenames (such as os.listdir()) to return Python
1305 string objects pre-encoded using the default file system encoding for
1306 the platform. As this encoding is likely to be different from Python's
1307 default encoding, converting this name to a Unicode object before passing
1308 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001309 would attempt to use its default encoding (generally ASCII) rather than
1310 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001311
Tim Petersa814db52001-05-14 07:05:58 +00001312 In general, this change simply removes surprises when working with
1313 Unicode and the file system, making these operations work as you expect,
1314 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001315 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001316
Tim Peters61dff2b2001-05-08 15:43:37 +00001317- Float (and complex) literals in source code were evaluated to full
1318 precision only when running from a .py file; the same code loaded from a
1319 .pyc (or .pyo) file could suffer numeric differences starting at about the
1320 12th significant decimal digit. For example, on a machine with IEEE-754
1321 floating arithmetic,
1322
1323 x = 9007199254740992.0
1324 print long(x)
1325
1326 printed 9007199254740992 if run directly from .py, but 9007199254740000
1327 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1328 str(float) instead of repr(float) when building code objects. marshal
1329 now uses repr(float) instead, which should reproduce floats to full
1330 machine precision (assuming the platform C float<->string I/O conversion
1331 functions are of good quality).
1332
1333 This may cause floating-point results to change in some cases, and
1334 usually for the better, but may also cause numerically unstable
1335 algorithms to break.
1336
Tim Peters2f228e72001-05-13 00:19:31 +00001337- The implementation of dicts suffers fewer collisions, which has speed
1338 benefits. However, the order in which dict entries appear in dict.keys(),
1339 dict.values() and dict.items() may differ from previous releases for a
1340 given dict. Nothing is defined about this order, so no program should
1341 rely on it. Nevertheless, it's easy to write test cases that rely on the
1342 order by accident, typically because of printing the str() or repr() of a
1343 dict to an "expected results" file. See Lib/test/test_support.py's new
1344 sortdict(dict) function for a simple way to display a dict in sorted
1345 order.
1346
Tim Peters7a3bfc32001-06-12 01:22:22 +00001347- Many other small changes to dicts were made, resulting in faster
1348 operation along the most common code paths.
1349
Guido van Rossum10315822001-05-01 20:54:30 +00001350- Dictionary objects now support the "in" operator: "x in dict" means
1351 the same as dict.has_key(x).
1352
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001353- The update() method of dictionaries now accepts generic mapping
1354 objects. Specifically the argument object must support the .keys()
1355 and __getitem__() methods. This allows you to say, for example,
1356 {}.update(UserDict())
1357
Guido van Rossum10315822001-05-01 20:54:30 +00001358- Iterators were added; this is a generalized way of providing values
1359 to a for loop. See PEP 234. There's a new built-in function iter()
1360 to return an iterator. There's a new protocol to get the next value
1361 from an iterator using the next() method (in Python) or the
1362 tp_iternext slot (in C). There's a new protocol to get iterators
1363 using the __iter__() method (in Python) or the tp_iter slot (in C).
1364 Iterating (i.e. a for loop) over a dictionary generates its keys.
1365 Iterating over a file generates its lines.
1366
Tim Petersf553f892001-05-01 20:45:31 +00001367- The following functions were generalized to work nicely with iterator
1368 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001369 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001370 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1371 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001372 join() method of strings
1373 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001374 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1375 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001376 right-hand side of assignment statements with multiple targets, such as
1377 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001378
Tim Petersd85e1022001-05-11 21:51:48 +00001379- Accessing module attributes is significantly faster (for example,
1380 random.random or os.path or yourPythonModule.yourAttribute).
1381
Tim Peterse63415e2001-05-08 04:38:29 +00001382- Comparing dictionary objects via == and != is faster, and now works even
1383 if the keys and values don't support comparisons other than ==.
1384
Tim Peters95bf9392001-05-10 08:32:44 +00001385- Comparing dictionaries in ways other than == and != is slower: there were
1386 insecurities in the dict comparison implementation that could cause Python
1387 to crash if the element comparison routines for the dict keys and/or
1388 values mutated the dicts. Making the code bulletproof slowed it down.
1389
Tim Peterseb28ef22001-06-02 05:27:19 +00001390- Collisions in dicts are resolved via a new approach, which can help
1391 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001392 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001393 faster now. Thanks to Christian Tismer for pointing out the cause and
1394 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001395
Tim Peters52e155e2001-06-16 05:42:57 +00001396- repr() is much faster for large containers (dict, list, tuple).
1397
1398
Tim Petersa814db52001-05-14 07:05:58 +00001399Library
1400
Fred Drake960fdf92001-07-20 18:38:26 +00001401- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1402 were added to the string module. These a locale-indenpendent
1403 constants, unlike letters, lowercase, and uppercase. These are now
1404 use in appropriate locations in the standard library.
1405
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001406- The flags used in dlopen calls can now be configured using
1407 sys.setdlopenflags and queried using sys.getdlopenflags.
1408
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001409- Fredrik Lundh's xmlrpclib is now a standard library module. This
1410 provides full client-side XML-RPC support. In addition,
1411 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1412 one asyncore-based). Thanks to Eric Raymond for the documentation.
1413
Guido van Rossum643d3912001-07-05 14:46:25 +00001414- The xrange() object is simplified: it no longer supports slicing,
1415 repetition, comparisons, efficient 'in' checking, the tolist()
1416 method, or the start, stop and step attributes. See PEP 260.
1417
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001418- A new function fnmatch.filter to filter lists of file names was added.
1419
Barry Warsawffd674d2001-05-22 16:00:10 +00001420- calendar.py uses month and day names based on the current locale.
1421
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001422- strop is now *really* obsolete (this was announced before with 1.6),
1423 and issues DeprecationWarning when used (except for the four items
1424 that are still imported into string.py).
1425
Tim Petersa814db52001-05-14 07:05:58 +00001426- Cookie.py now sorts key+value pairs by key in output strings.
1427
1428- pprint.isrecursive(object) didn't correctly identify recursive objects.
1429 Now it does.
1430
Tim Peters95b3f782001-05-14 18:39:41 +00001431- pprint functions now much faster for large containers (tuple, list, dict).
1432
Tim Peters7b9542a2001-06-10 23:40:19 +00001433- New 'q' and 'Q' format codes in the struct module, corresponding to C
1434 types "long long" and "unsigned long long" (on Windows, __int64). In
1435 native mode, these can be used only when the platform C compiler supports
1436 these types (when HAVE_LONG_LONG is #define'd by the Python config
1437 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001438 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1439 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001440
Guido van Rossum83213cc2001-06-12 16:48:52 +00001441- The site module installs a new built-in function 'help' that invokes
1442 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1443 it displays a message reminding the user to use 'help()' or
1444 'help(object)'.
1445
Tim Petersa814db52001-05-14 07:05:58 +00001446Tests
1447
1448- New test_mutants.py runs dict comparisons where the key and value
1449 comparison operators mutute the dicts randomly during comparison. This
1450 rapidly causes Python to crash under earlier releases (not for the faint
1451 of heart: it can also cause Win9x to freeze or reboot!).
1452
1453- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001454 pprint.isreadable() return sensible results. Also verifies that simple
1455 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001456
Tim Peters4324aa32001-05-28 22:30:08 +00001457C API
1458
1459- Removed the unused last_is_sticky argument from the internal
1460 _PyTuple_Resize(). If this affects you, you were cheating.
1461
1462
Guido van Rossum55a78992001-07-17 17:22:32 +00001463======================================================================
1464
1465
Guido van Rossumffe13be2001-04-16 18:46:45 +00001466What's New in Python 2.1 (final)?
1467=================================
1468
1469We only changed a few things since the last release candidate, all in
1470Python library code:
1471
1472- A bug in the locale module was fixed that affected locales which
1473 define no grouping for numeric formatting.
1474
1475- A few bugs in the weakref module's implementations of weak
1476 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1477 and the test suite was updated to check for these bugs.
1478
1479- An old bug in the os.path.walk() function (introduced in Python
1480 2.0!) was fixed: a non-existent file would cause an exception
1481 instead of being ignored.
1482
1483- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1484 PyChecker.
1485
1486
Guido van Rossum5b08f132001-04-16 02:05:23 +00001487What's New in Python 2.1c2?
1488===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001489
Guido van Rossum5b08f132001-04-16 02:05:23 +00001490A flurry of small changes, and one showstopper fixed in the nick of
1491time made it necessary to release another release candidate. The list
1492here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001493
Guido van Rossum5b08f132001-04-16 02:05:23 +00001494Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001495
Guido van Rossum5b08f132001-04-16 02:05:23 +00001496- Tim discovered a nasty bug in the dictionary code, caused by
1497 PyDict_Next() calling dict_resize(), and the GC code's use of
1498 PyDict_Next() violating an assumption in dict_items(). This was
1499 fixed with considerable amounts of band-aid, but the net effect is a
1500 saner and more robust implementation.
1501
1502- Made a bunch of symbols static that were accidentally global.
1503
1504Build and Ports
1505
1506- The setup.py script didn't check for a new enough version of zlib
1507 (1.1.3 is needed). Now it does.
1508
1509- Changed "make clean" target to also remove shared libraries.
1510
1511- Added a more general warning about the SGI Irix optimizer to README.
1512
1513Library
1514
1515- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1516 omitted the slash between host and file.html.
1517
1518- The mailbox module's _Mailbox class contained a completely broken
1519 and undocumented seek() method. Ripped it out.
1520
1521- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1522 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1523
1524- Fixed a few last-minute bugs in unittest.
1525
1526Extensions
1527
1528- Reverted the patch to the OpenSSL code in socketmodule.c to support
1529 RAND_status() and the EGD, and the subsequent patch that tried to
1530 fix it for pre-0.9.5 versions; the problem with the patch is that on
1531 some systems it issues a warning whenever socket is imported, and
1532 that's unacceptable.
1533
1534Tests
1535
1536- Fixed the pickle tests to work with "import test.test_pickle".
1537
1538- Tweaked test_locale.py to actually run the test Windows.
1539
1540- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1541 not "wb" (which is not a valid mode at all).
1542
1543- Fix pstats browser crashes. Import readline if it exists to make
1544 the user interface nicer.
1545
1546- Add "import thread" to the top of test modules that import the
1547 threading module (test_asynchat and test_threadedtempfile). This
1548 prevents test failures caused by a broken threading module resulting
1549 from a previously caught failed import.
1550
1551- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1552 needed on some platforms (e.g. Solaris 8) when the tests are run
1553 twice in succession.
1554
1555- Skip rather than fail test_sunaudiodev if no audio device is found.
1556
1557
1558What's New in Python 2.1c1?
1559===========================
1560
1561This list was significantly updated when 2.1c2 was released; the 2.1c1
1562release didn't mention most changes that were actually part of 2.1c1:
1563
1564Legal
1565
1566- Copyright was assigned to the Python Software Foundation (PSF) and a
1567 PSF license (very similar to the CNRI license) was added.
1568
1569- The CNRI copyright notice was updated to include 2001.
1570
1571Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001572
Guido van Rossumc9932722001-04-12 02:31:27 +00001573- After a public outcry, assignment to __debug__ is no longer illegal;
1574 instead, a warning is issued. It will become illegal in 2.2.
1575
Guido van Rossum5b08f132001-04-16 02:05:23 +00001576- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1577 "%#x" now always prepends "0x", even if the value is zero.
1578
1579- Fixed some nits in the bytecode compiler.
1580
1581- Fixed core dumps when calling certain kinds of non-functions.
1582
1583- Fixed various core dumps caused by reference count bugs.
1584
1585Build and Ports
1586
1587- Use INSTALL_SCRIPT to install script files.
1588
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001589- New port: SCO Unixware 7, by Billy G. Allie.
1590
Guido van Rossum5b08f132001-04-16 02:05:23 +00001591- Updated RISCOS port.
1592
1593- Updated BeOS port and notes.
1594
1595- Various other porting problems resolved.
1596
1597Library
1598
1599- The TERMIOS and SOCKET modules are now truly obsolete and
1600 unnecessary. Their symbols are incorporated in the termios and
1601 socket modules.
1602
1603- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1604 better tests for pickling.
1605
1606- threading: make Condition.wait() robust against KeyboardInterrupt.
1607
1608- zipfile: add support to zipfile to support opening an archive
1609 represented by an open file rather than a file name. Fix bug where
1610 the archive was not properly closed. Fixed a bug in this bugfix
1611 where flush() was called for a read-only file.
1612
1613- imputil: added an uninstall() method to the ImportManager.
1614
1615- Canvas: fixed bugs in lower() and tkraise() methods.
1616
1617- SocketServer: API change (added overridable close_request() method)
1618 so that the TCP server can explicitly close the request.
1619
1620- pstats: Eric Raymond added a simple interactive statistics browser,
1621 invoked when the module is run as a script.
1622
1623- locale: fixed a problem in format().
1624
1625- webbrowser: made it work when the BROWSER environment variable has a
1626 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1627 KDE 2. Fixed some other nits.
1628
1629- unittest: changes to allow using a different exception than
1630 AssertionError, and added a few more function aliases. Some other
1631 small changes.
1632
1633- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1634
1635- asynchat: fixed a critical bug in asynchat that slipped through the
1636 2.1b2 release. Fixed another rare bug.
1637
1638- Fix some unqualified except: clauses (always a bad code example).
1639
1640XML
1641
1642- pyexpat: new API get_version_string().
1643
1644- Fixed some minidom bugs.
1645
1646Extensions
1647
1648- Fixed a core dump in _weakref. Removed the weakref.mapping()
1649 function (it adds nothing to the API).
1650
1651- Rationalized the use of header files in the readline module, to make
1652 it compile (albeit with some warnings) with the very recent readline
1653 4.2, without breaking for earlier versions.
1654
1655- Hopefully fixed a buffering problem in linuxaudiodev.
1656
1657- Attempted a fix to make the OpenSSL support in the socket module
1658 work again with pre-0.9.5 versions of OpenSSL.
1659
1660Tests
1661
1662- Added a test case for asynchat and asyncore.
1663
1664- Removed coupling between tests where one test failing could break
1665 another.
1666
1667Tools
1668
1669- Ping added an interactive help browser to pydoc, fixed some nits
1670 in the rest of the pydoc code, and added some features to his
1671 inspect module.
1672
1673- An updated python-mode.el version 4.1 which integrates Ken
1674 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1675 much nicer in XEmacs and Emacs. When stepping through your program
1676 with pdb, in either the shell window or the *Python* window, the
1677 source file and line will be tracked by an arrow. Very cool!
1678
1679- IDLE: syntax warnings in interactive mode are changed into errors.
1680
1681- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001682 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001683
1684- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001685
Barry Warsaw11e89c72001-04-11 20:37:57 +00001686
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001687What's New in Python 2.1 beta 2?
1688================================
1689
Guido van Rossum053ae352001-03-22 14:17:21 +00001690(Unlisted are many fixed bugs, more documentation, etc.)
1691
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001692Core language, builtins, and interpreter
1693
Guido van Rossum053ae352001-03-22 14:17:21 +00001694- The nested scopes work (enabled by "from __future__ import
1695 nested_scopes") is completed; in particular, the future now extends
1696 into code executed through exec, eval() and execfile(), and into the
1697 interactive interpreter.
1698
1699- When calling a base class method (e.g. BaseClass.__init__(self)),
1700 this is now allowed even if self is not strictly spoken a class
1701 instance (e.g. when using metaclasses or the Don Beaudry hook).
1702
1703- Slice objects are now comparable but not hashable; this prevents
1704 dict[:] from being accepted but meaningless.
1705
1706- Complex division is now calculated using less braindead algorithms.
1707 This doesn't change semantics except it's more likely to give useful
1708 results in extreme cases. Complex repr() now uses full precision
1709 like float repr().
1710
1711- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1712
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001713- It is illegal to assign to the name __debug__, which is set when the
1714 interpreter starts. It is effectively a compile-time constant.
1715
1716- A warning will be issued if a global statement for a variable
1717 follows a use or assignment of that variable.
1718
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001719Standard library
1720
Guido van Rossum053ae352001-03-22 14:17:21 +00001721- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1722 inspired by JUnit), is now part of the standard library. You now
1723 have a choice of two testing frameworks: unittest requires you to
1724 write testcases as separate code, doctest gathers them from
1725 docstrings. Both approaches have their advantages and
1726 disadvantages.
1727
1728- A new module Tix was added, which wraps the Tix extension library
1729 for Tk. With that module, it is not necessary to statically link
1730 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1731 require" command. See Demo/tix/.
1732
1733- tzparse.py is now obsolete.
1734
1735- In gzip.py, the seek() and tell() methods are removed -- they were
1736 non-functional anyway, and it's better if callers can test for their
1737 existence with hasattr().
1738
1739Python/C API
1740
1741- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1742 that's already in the dictionary during a PyDict_Next() iteration.
1743 This used to fail occasionally when a dictionary resize operation
1744 could be triggered that would rehash all the keys. All other
1745 modifications to the dictionary are still off-limits during a
1746 PyDict_Next() iteration!
1747
1748- New extended APIs related to passing compiler variables around.
1749
1750- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1751 implement isinstance() and issubclass().
1752
1753- Py_BuildValue() now has a "D" conversion to create a Python complex
1754 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001755
Fred Drake4e262a92001-03-22 18:26:47 +00001756- Extensions types which support weak references must now set the
1757 field allocated for the weak reference machinery to NULL themselves;
1758 this is done to avoid the cost of checking each object for having a
1759 weakly referencable type in PyObject_INIT(), since most types are
1760 not weakly referencable.
1761
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001762- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1763 free variables and cell variables to and from the frame's f_locals.
1764
1765- Variants of several functions defined in pythonrun.h have been added
1766 to support the nested_scopes future statement. The variants all end
1767 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1768 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1769 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001770 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001771
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001772Distutils
1773
1774- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1775 into the release tree.
1776
Tim Peters0e57abf2001-05-02 07:39:38 +00001777- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001778 (an uninstaller, more customization of the installer's display)
1779
1780- from Jack Jansen: added Mac-specific code to generate a dialog for
1781 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001782 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001783 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001784
1785- added 'platforms' and 'keywords' to the set of metadata that can be
1786 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001787
1788- applied patches from Jason Tishler to make the compiler class work with
1789 Cygwin.
1790
1791
Tim Peters2fe289a2001-03-01 22:19:38 +00001792What's New in Python 2.1 beta 1?
1793================================
Tim Petersd66595f2001-02-04 03:09:53 +00001794
1795Core language, builtins, and interpreter
1796
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001797- Following an outcry from the community about the amount of code
1798 broken by the nested scopes feature introduced in 2.1a2, we decided
1799 to make this feature optional, and to wait until Python 2.2 (or at
1800 least 6 months) to make it standard. The option can be enabled on a
1801 per-module basis by adding "from __future__ import nested_scopes" at
1802 the beginning of a module (before any other statements, but after
1803 comments and an optional docstring). See PEP 236 (Back to the
1804 __future__) for a description of the __future__ statement. PEP 227
1805 (Statically Nested Scopes) has been updated to reflect this change,
1806 and to clarify the semantics in a number of endcases.
1807
1808- The nested scopes code, when enabled, has been hardened, and most
1809 bugs and memory leaks in it have been fixed.
1810
1811- Compile-time warnings are now generated for a number of conditions
1812 that will break or change in meaning when nested scopes are enabled:
1813
1814 - Using "from...import *" or "exec" without in-clause in a function
1815 scope that also defines a lambda or nested function with one or
1816 more free (non-local) variables. The presence of the import* or
1817 bare exec makes it impossible for the compiler to determine the
1818 exact set of local variables in the outer scope, which makes it
1819 impossible to determine the bindings for free variables in the
1820 inner scope. To avoid the warning about import *, change it into
1821 an import of explicitly name object, or move the import* statement
1822 to the global scope; to avoid the warning about bare exec, use
1823 exec...in... (a good idea anyway -- there's a possibility that
1824 bare exec will be deprecated in the future).
1825
1826 - Use of a global variable in a nested scope with the same name as a
1827 local variable in a surrounding scope. This will change in
1828 meaning with nested scopes: the name in the inner scope will
1829 reference the variable in the outer scope rather than the global
1830 of the same name. To avoid the warning, either rename the outer
1831 variable, or use a global statement in the inner function.
1832
Neil Schemenauera35c6882001-02-27 04:45:05 +00001833- An optional object allocator has been included. This allocator is
1834 optimized for Python objects and should be faster and use less memory
1835 than the standard system allocator. It is not enabled by default
1836 because of possible thread safety problems. The allocator is only
1837 protected by the Python interpreter lock and it is possible that some
1838 extension modules require a thread safe allocator. The object
1839 allocator can be enabled by providing the "--with-pymalloc" option to
1840 configure.
1841
Tim Petersd66595f2001-02-04 03:09:53 +00001842Standard library
1843
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001844- pyexpat now detects the expat version if expat.h defines it. A
1845 number of additional handlers are provided, which are only available
1846 since expat 1.95. In addition, the methods SetParamEntityParsing and
1847 GetInputContext of Parser objects are available with 1.95.x
1848 only. Parser objects now provide the ordered_attributes and
1849 specified_attributes attributes. A new module expat.model was added,
1850 which offers a number of additional constants if 1.95.x is used.
1851
1852- xml.dom offers the new functions registerDOMImplementation and
1853 getDOMImplementation.
1854
1855- xml.dom.minidom offers a toprettyxml method. A number of DOM
1856 conformance issues have been resolved. In particular, Element now
1857 has an hasAttributes method, and the handling of namespaces was
1858 improved.
1859
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001860- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1861 getting information about live Python code, and pydoc.py, a module
1862 for interactively converting docstrings to HTML or text.
1863 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001864 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001865 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1866 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001867
Tim Peters1eff7962001-03-01 02:31:33 +00001868- New library module difflib.py, primarily packaging the SequenceMatcher
1869 class at the heart of the popular ndiff.py file-comparison tool.
1870
1871- doctest.py (a framework for verifying Python code examples in docstrings)
1872 is now part of the std library.
1873
Tim Petersd66595f2001-02-04 03:09:53 +00001874Windows changes
1875
Guido van Rossume3955a82001-03-02 14:05:59 +00001876- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1877 small GUI that lets you browse the module docstrings using your
1878 default web browser.
1879
Tim Peters1eff7962001-03-01 02:31:33 +00001880- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1881 Platforms) is implemented. See
1882
1883 http://python.sourceforge.net/peps/pep-0235.html
1884
1885 for full details, especially the "Current Lower-Left Semantics" section.
1886 The new Windows import rules are simpler than before:
1887
1888 A. If the PYTHONCASEOK environment variable exists, same as
1889 before: silently accept the first case-insensitive match of any
1890 kind; raise ImportError if none found.
1891
1892 B. Else search sys.path for the first case-sensitive match; raise
1893 ImportError if none found.
1894
1895 The same rules have been implented on other platforms with case-
1896 insensitive but case-preserving filesystems too (including Cygwin, and
1897 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001898
Tim Peters25a9ce32001-02-19 07:06:36 +00001899- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1900 what it's supposed to do (and does do under NT and 2000) via direct
1901 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001902 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001903 all Win9x systems before.
1904
Tim Peters1eff7962001-03-01 02:31:33 +00001905- Build: Subproject _test (effectively) renamed to _testcapi.
1906
Tim Peters2fe289a2001-03-01 22:19:38 +00001907New platforms
1908
1909- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1910 Thanks to Steven Majewski!
1911
1912- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1913 Tishler!
1914
Guido van Rossum9089b272001-03-02 06:49:50 +00001915- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1916 Schwertberger! See RISCOS/README for more information -- it seems
1917 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001918 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001919
Tim Peters25a9ce32001-02-19 07:06:36 +00001920
Tim Petersd7b5e882001-01-25 03:36:26 +00001921What's New in Python 2.1 alpha 2?
1922=================================
Tim Peters40ead762001-01-27 05:35:26 +00001923
Tim Petersd7b5e882001-01-25 03:36:26 +00001924Core language, builtins, and interpreter
1925
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001926- Scopes nest. If a name is used in a function or class, but is not
1927 local, the definition in the nearest enclosing function scope will
1928 be used. One consequence of this change is that lambda statements
1929 could reference variables in the namespaces where the lambda is
1930 defined. In some unusual cases, this change will break code.
1931
1932 In all previous version of Python, names were resolved in exactly
1933 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001934 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001935 function A is defined within a function B, the names bound in B are
1936 not visible in A. The new rules make names bound in B visible in A,
1937 unless A contains a name binding that hides the binding in B.
1938
1939 Section 4.1 of the reference manual describes the new scoping rules
1940 in detail. The test script in Lib/test/test_scope.py demonstrates
1941 some of the effects of the change.
1942
1943 The new rules will cause existing code to break if it defines nested
1944 functions where an outer function has local variables with the same
1945 name as globals or builtins used by the inner function. Example:
1946
1947 def munge(str):
1948 def helper(x):
1949 return str(x)
1950 if type(str) != type(''):
1951 str = helper(str)
1952 return str.strip()
1953
1954 Under the old rules, the name str in helper() is bound to the
1955 builtin function str(). Under the new rules, it will be bound to
1956 the argument named str and an error will occur when helper() is
1957 called.
1958
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001959- The compiler will report a SyntaxError if "from ... import *" occurs
1960 in a function or class scope. The language reference has documented
1961 that this case is illegal, but the compiler never checked for it.
1962 The recent introduction of nested scope makes the meaning of this
1963 form of name binding ambiguous. In a future release, the compiler
1964 may allow this form when there is no possibility of ambiguity.
1965
Tim Peters40ead762001-01-27 05:35:26 +00001966- repr(string) is easier to read, now using hex escapes instead of octal,
1967 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1968
1969 >>> "\texample \r\n" + chr(0) + chr(255)
1970 '\texample \r\n\x00\xff' # in 2.1
1971 '\011example \015\012\000\377' # in 2.0
1972
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001973- Functions are now compared and hashed by identity, not by value, since
1974 the func_code attribute is writable.
1975
Fred Drakefb9d7122001-02-01 20:00:40 +00001976- Weak references (PEP 205) have been added. This involves a few
1977 changes in the core, an extension module (_weakref), and a Python
1978 module (weakref). The weakref module is the public interface. It
1979 includes support for "explicit" weak references, proxy objects, and
1980 mappings with weakly held values.
1981
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001982- A 'continue' statement can now appear in a try block within the body
1983 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001984 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001985
Tim Petersd7b5e882001-01-25 03:36:26 +00001986Standard library
1987
Barry Warsaw30dbd142001-01-31 22:14:01 +00001988- mailbox.py now has a new class, PortableUnixMailbox which is
1989 identical to UnixMailbox but uses a more portable scheme for
1990 determining From_ separators. Also, the constructors for all the
1991 classes in this module have a new optional `factory' argument, which
1992 is a callable used when new message classes must be instantiated by
1993 the next() method.
1994
Tim Petersd7b5e882001-01-25 03:36:26 +00001995- random.py is now self-contained, and offers all the functionality of
1996 the now-deprecated whrandom.py. See the docs for details. random.py
1997 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001998 and restoring the internal state of the generator; and jumpahead(n),
1999 for quickly forcing the internal state to be the same as if n calls to
2000 random() had been made. The latter is particularly useful for multi-
2001 threaded programs, creating one instance of the random.Random() class for
2002 each thread, then using .jumpahead() to force each instance to use a
2003 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002004
Tim Peters0de88fc2001-02-01 04:59:18 +00002005- random.py's seed() function is new. For bit-for-bit compatibility with
2006 prior releases, use the whseed function instead. The new seed function
2007 addresses two problems: (1) The old function couldn't produce more than
2008 about 2**24 distinct internal states; the new one about 2**45 (the best
2009 that can be done in the Wichmann-Hill generator). (2) The old function
2010 sometimes produced identical internal states when passed distinct
2011 integers, and there was no simple way to predict when that would happen;
2012 the new one guarantees to produce distinct internal states for all
2013 arguments in [0, 27814431486576L).
2014
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002015- The socket module now supports raw packets on Linux. The socket
2016 family is AF_PACKET.
2017
Tim Peters9ea17ac2001-02-02 05:57:15 +00002018- test_capi.py is a start at running tests of the Python C API. The tests
2019 are implemented by the new Modules/_testmodule.c.
2020
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002021- A new extension module, _symtable, provides provisional access to the
2022 internal symbol table used by the Python compiler. A higher-level
2023 interface will be added on top of _symtable in a future release.
2024
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002025- Removed the obsolete soundex module.
2026
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002027- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2028 the isSameNode method; NamedNodeMap the get method.
2029
2030- xml.sax.expatreader supports the lexical handler property; it
2031 generates comment, startCDATA, and endCDATA events.
2032
Tim Petersee826f82001-01-31 19:39:44 +00002033Windows changes
2034
2035- Build procedure: the zlib project is built in a different way that
2036 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002037 the zlib binary used. See PCbuild\readme.txt for details. Your old
2038 zlib-related directories can be deleted; you'll need to download fresh
2039 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002040
Tim Peters9ea17ac2001-02-02 05:57:15 +00002041- Build: New subproject _test for the benefit of test_capi.py (see above).
2042
Tim Petersb16c56f2001-02-02 21:24:51 +00002043- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2044 interface to some Python compiler internals).
2045
2046- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002047 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002048
Tim Petersa3a3a032000-11-30 05:22:44 +00002049What's New in Python 2.1 alpha 1?
2050=================================
2051
2052Core language, builtins, and interpreter
2053
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002054- There is a new Unicode companion to the PyObject_Str() API
2055 called PyObject_Unicode(). It behaves in the same way as the
2056 former, but assures that the returned value is an Unicode object
2057 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002058
Guido van Rossumf98eda02001-01-17 15:54:45 +00002059- The comparison operators support "rich comparison overloading" (PEP
2060 207). C extension types can provide a rich comparison function in
2061 the new tp_richcompare slot in the type object. The cmp() function
2062 and the C function PyObject_Compare() first try the new rich
2063 comparison operators before trying the old 3-way comparison. There
2064 is also a new C API PyObject_RichCompare() (which also falls back on
2065 the old 3-way comparison, but does not constrain the outcome of the
2066 rich comparison to a Boolean result).
2067
2068 The rich comparison function takes two objects (at least one of
2069 which is guaranteed to have the type that provided the function) and
2070 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2071 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2072 object, which may be NotImplemented (in which case the tp_compare
2073 slot function is used as a fallback, if defined).
2074
2075 Classes can overload individual comparison operators by defining one
2076 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002077 __ge__. There are no explicit "reflected argument" versions of
2078 these; instead, __lt__ and __gt__ are each other's reflection,
2079 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2080 reflection (similar at the C level). No other implications are
2081 made; in particular, Python does not assume that == is the Boolean
2082 inverse of !=, or that < is the Boolean inverse of >=. This makes
2083 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002084
2085 Classes or types that want to implement (in)equality tests but not
2086 the ordering operators (i.e. unordered types) should implement ==
2087 and !=, and raise an error for the ordering operators.
2088
Guido van Rossuma88479f2001-01-18 14:28:08 +00002089 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002090 Boolean; e.g. a matrix type might want to return a matrix of bits
2091 for A < B, giving elementwise comparisons. Such types should ensure
2092 that any interpretation of their value in a Boolean context raises
2093 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2094 at the C level) to always raise an exception.
2095
Guido van Rossuma88479f2001-01-18 14:28:08 +00002096- Complex numbers use rich comparisons to define == and != but raise
2097 an exception for <, <=, > and >=. Unfortunately, this also means
2098 that cmp() of two complex numbers raises an exception when the two
2099 numbers differ. Since it is not mathematically meaningful to compare
2100 complex numbers except for equality, I hope that this doesn't break
2101 too much code.
2102
Tim Peters3389f192001-02-18 08:48:49 +00002103- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002104 not defined by the language, other than that it's arbitrary but
2105 consistent (see the Reference Manual). An implementation detail changed
2106 in 2.1a1 such that None now compares less than any other object. Code
2107 relying on this new behavior (like code that relied on the previous
2108 behavior) does so at its own risk.
2109
Barry Warsaw573b5412001-01-15 20:43:18 +00002110- Functions and methods now support getting and setting arbitrarily
2111 named attributes (PEP 232). Functions have a new __dict__
2112 (a.k.a. func_dict) which hold the function attributes. Methods get
2113 and set attributes on their underlying im_func. It is a TypeError
2114 to set an attribute on a bound method.
2115
Guido van Rossum051e3352001-01-15 19:11:10 +00002116- The xrange() object implementation has been improved so that
2117 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2118 limitation that in this case len(xrange(sys.maxint)) can't be
2119 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2120 work fine as long as the index i doesn't actually reach 2**31.
2121 (Python uses regular ints for sequence and string indices; fixing
2122 that is much more work.)
2123
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002124- Two changes to from...import:
2125
Guido van Rossumba381232001-02-03 15:06:40 +00002126 1) "from M import X" now works even if (after loading module M)
2127 sys.modules['M'] is not a real module; it's basically a getattr()
2128 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002129
2130 2) "from M import *" now looks for M.__all__ to decide which names to
2131 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2132 filters out names starting with '_' as before. Whether or not
2133 __all__ exists, there's no restriction on the type of M.
2134
Guido van Rossumf61f1662001-01-10 20:13:55 +00002135- File objects have a new method, xreadlines(). This is the fastest
2136 way to iterate over all lines in a file:
2137
2138 for line in file.xreadlines():
2139 ...do something to line...
2140
2141 See the xreadlines module (mentioned below) for how to do this for
2142 other file-like objects.
2143
2144- Even if you don't use file.xreadlines(), you may expect a speedup on
2145 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002146 quite a bit in platform-specific ways: on systems (like Linux) that
2147 support flockfile(), getc_unlocked(), and funlockfile(), those are
2148 used by default. On systems (like Windows) without getc_unlocked(),
2149 a complicated (but still thread-safe) method using fgets() is used by
2150 default.
2151
Tim Petersd52269b2001-01-25 06:23:18 +00002152 You can force use of the fgets() method by #define'ing
2153 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002154 getc_unlocked()).
2155
Tim Petersd52269b2001-01-25 06:23:18 +00002156 You can force fgets() not to be used by #define'ing
2157 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002158 test_bufio.py fails -- and let us know if it does!).
2159
2160- In addition, the fileinput module, while still slower than the other
2161 methods on most platforms, has been sped up too, by using
2162 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002163
2164- Support for run-time warnings has been added, including a new
2165 command line option (-W) to specify the disposition of warnings.
2166 See the description of the warnings module below.
2167
2168- Extensive changes have been made to the coercion code. This mostly
2169 affects extension modules (which can now implement mixed-type
2170 numerical operators without having to use coercion), but
2171 occasionally, in boundary cases the coercion semantics have changed
2172 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002173 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002174 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002175 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002176
Guido van Rossumf98eda02001-01-17 15:54:45 +00002177- In connection with the coercion changes, a new built-in singleton
2178 object, NotImplemented is defined. This can be returned for
2179 operations that wish to indicate they are not implemented for a
2180 particular combination of arguments. From C, this is
2181 Py_NotImplemented.
2182
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002183- The interpreter accepts now bytecode files on the command line even
2184 if they do not have a .pyc or .pyo extension. On Linux, after executing
2185
Martin v. Löwise214baa2001-02-04 22:37:56 +00002186import imp,sys,string
2187magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2188reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2189open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002190
2191 any byte code file can be used as an executable (i.e. as an argument
2192 to execve(2)).
2193
Tim Peters9940b802000-12-01 07:59:35 +00002194- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002195 character. In 1.6 and earlier, they never produced a sign,
2196 and raised an error if the value of the long was too large
2197 to fit in a Python int. In 2.0, they produced a sign if and
2198 only if too large to fit in an int. This was inconsistent
2199 across platforms (because the size of an int varies across
2200 platforms), and inconsistent with hex() and oct(). Example:
2201
2202 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002203 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002204 'ffffffbe' # in 2.0 and before, on 32-bit machines
2205 >>> hex(-0x42L)
2206 '-0x42L' # in all versions of Python
2207
Tim Peters9940b802000-12-01 07:59:35 +00002208 The behavior of %d formats for negative Python longs remains
2209 the same as in 2.0 (although in 1.6 and before, they raised
2210 an error if the long didn't fit in a Python int).
2211
2212 %u formats don't make sense for Python longs, but are allowed
2213 and treated the same as %d in 2.1. In 2.0, a negative long
2214 formatted via %u produced a sign if and only if too large to
2215 fit in an int. In 1.6 and earlier, a negative long formatted
2216 via %u raised an error if it was too big to fit in an int.
2217
Guido van Rossum3661d392000-12-12 22:10:31 +00002218- Dictionary objects have an odd new method, popitem(). This removes
2219 an arbitrary item from the dictionary and returns it (in the form of
2220 a (key, value) pair). This can be useful for algorithms that use a
2221 dictionary as a bag of "to do" items and repeatedly need to pick one
2222 item. Such algorithms normally end up running in quadratic time;
2223 using popitem() they can usually be made to run in linear time.
2224
Tim Peters36cdad12000-12-29 02:06:45 +00002225Standard library
2226
Thomas Woutersfe385252001-01-19 23:16:56 +00002227- In the time module, the time argument to the functions strftime,
2228 localtime, gmtime, asctime and ctime is now optional, defaulting to
2229 the current time (in the local timezone).
2230
Guido van Rossumda91f222001-01-15 16:36:08 +00002231- The ftplib module now defaults to passive mode, which is deemed a
2232 more useful default given that clients are often inside firewalls
2233 these days. Note that this could break if ftplib is used to connect
2234 to a *server* that is inside a firewall, from outside; this is
2235 expected to be a very rare situation. To fix that, you can call
2236 ftp.set_pasv(0).
2237
Martin v. Löwis10a27872001-01-13 09:54:41 +00002238- The module site now treats .pth files not only for path configuration,
2239 but also supports extensions to the initialization code: Lines starting
2240 with import are executed.
2241
Guido van Rossumf61f1662001-01-10 20:13:55 +00002242- There's a new module, warnings, which implements a mechanism for
2243 issuing and filtering warnings. There are some new built-in
2244 exceptions that serve as warning categories, and a new command line
2245 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2246 turns warnings into errors). warnings.warn(message[, category])
2247 issues a warning message; this can also be called from C as
2248 PyErr_Warn(category, message).
2249
2250- A new module xreadlines was added. This exports a single factory
2251 function, xreadlines(). The intention is that this code is the
2252 absolutely fastest way to iterate over all lines in an open
2253 file(-like) object:
2254
2255 import xreadlines
2256 for line in xreadlines.xreadlines(file):
2257 ...do something to line...
2258
2259 This is equivalent to the previous the speed record holder using
2260 file.readlines(sizehint). Note that if file is a real file object
2261 (as opposed to a file-like object), this is equivalent:
2262
2263 for line in file.xreadlines():
2264 ...do something to line...
2265
Tim Peters36cdad12000-12-29 02:06:45 +00002266- The bisect module has new functions bisect_left, insort_left,
2267 bisect_right and insort_right. The old names bisect and insort
2268 are now aliases for bisect_right and insort_right. XXX_right
2269 and XXX_left methods differ in what happens when the new element
2270 compares equal to one or more elements already in the list: the
2271 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002272 right. Code that doesn't care where equal elements end up should
2273 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002274
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002275- The new curses.panel module wraps the panel library that forms part
2276 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2277
Guido van Rossumf61f1662001-01-10 20:13:55 +00002278- The SocketServer module now sets the allow_reuse_address flag by
2279 default in the TCPServer class.
2280
2281- A new function, sys._getframe(), returns the stack frame pointer of
2282 the caller. This is intended only as a building block for
2283 higher-level mechanisms such as string interpolation.
2284
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002285- The pyexpat module supports a number of new handlers, which are
2286 available only in expat 1.2. If invocation of a callback fails, it
2287 will report an additional frame in the traceback. Parser objects
2288 participate now in garbage collection. If expat reports an unknown
2289 encoding, pyexpat will try to use a Python codec; that works only
2290 for single-byte charsets. The parser type objects is exposed as
2291 XMLParserObject.
2292
2293- xml.dom now offers standard definitions for symbolic node type and
2294 exception code constants, and a hierarchy of DOM exceptions. minidom
2295 was adjusted to use them.
2296
2297- The conformance of xml.dom.minidom to the DOM specification was
2298 improved. It detects a number of additional error cases; the
2299 previous/next relationship works even when the tree is modified;
2300 Node supports the normalize() method; NamedNodeMap, DocumentType and
2301 DOMImplementation classes were added; Element supports the
2302 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2303 method.
2304
Guido van Rossumf61f1662001-01-10 20:13:55 +00002305Build issues
2306
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002307- For Unix (and Unix-compatible) builds, configuration and building of
2308 extension modules is now greatly automated. Rather than having to
2309 edit the Modules/Setup file to indicate which modules should be
2310 built and where their include files and libraries are, a
2311 distutils-based setup.py script now takes care of building most
2312 extension modules. All extension modules built this way are built
2313 as shared libraries. Only a few modules that must be linked
2314 statically are still listed in the Setup file; you won't need to
2315 edit their configuration.
2316
2317- Python should now build out of the box on Cygwin. If it doesn't,
2318 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002319
2320- Python now always uses its own (renamed) implementation of getopt()
2321 -- there's too much variation among C library getopt()
2322 implementations.
2323
2324- C++ compilers are better supported; the CXX macro is always set to a
2325 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002326
Tim Petersd92dfe02000-12-12 01:18:41 +00002327Windows changes
2328
2329- select module: By default under Windows, a select() call
2330 can specify no more than 64 sockets. Python now boosts
2331 this Microsoft default to 512. If you need even more than
2332 that, see the MS docs (you'll need to #define FD_SETSIZE
2333 and recompile Python from source).
2334
Guido van Rossumf61f1662001-01-10 20:13:55 +00002335- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2336 subdirectory is no more!
2337
Tim Petersa3a3a032000-11-30 05:22:44 +00002338
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002339What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002340=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002341
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002342Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002343changes are in the file HISTORY. If you are making the jump directly
2344from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2345HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002346
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002347Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2348the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2349http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002350
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002351--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002352
2353======================================================================
2354
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002355What's new in 2.0 (since release candidate 1)?
2356==============================================
2357
2358Standard library
2359
2360- The copy_reg module was modified to clarify its intended use: to
2361 register pickle support for extension types, not for classes.
2362 pickle() will raise a TypeError if it is passed a class.
2363
2364- Fixed a bug in gettext's "normalize and expand" code that prevented
2365 it from finding an existing .mo file.
2366
2367- Restored support for HTTP/0.9 servers in httplib.
2368
Tim Peters989b7b92000-10-16 20:24:53 +00002369- The math module was changed to stop raising OverflowError in case of
2370 underflow, and return 0 instead in underflow cases. Whether Python
2371 used to raise OverflowError in case of underflow was platform-
2372 dependent (it did when the platform math library set errno to ERANGE
2373 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002374
2375- Fixed a bug in StringIO that occurred when the file position was not
2376 at the end of the file and write() was called with enough data to
2377 extend past the end of the file.
2378
2379- Fixed a bug that caused Tkinter error messages to get lost on
2380 Windows. The bug was fixed by replacing direct use of
2381 interp->result with Tcl_GetStringResult(interp).
2382
2383- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2384 redirect response.
2385
2386- Several changes were made to distutils: Some debugging code was
2387 removed from util. Fixed the installer used when an external zip
2388 program (like WinZip) is not found; the source code for this
2389 installer is in Misc/distutils. check_lib() was modified to behave
2390 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2391 test for whether installed modules are on sys.path was changed to
2392 use both normcase() and normpath().
2393
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002394- Several minor bugs were fixed in the xml package (the minidom,
2395 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002396
2397- The regression test driver (regrtest.py) behavior when invoked with
2398 -l changed: It now reports a count of objects that are recognized as
2399 garbage but not freed by the garbage collector.
2400
Tim Peters989b7b92000-10-16 20:24:53 +00002401- The regression test for the math module was changed to test
2402 exceptional behavior when the test is run in verbose mode. Python
2403 cannot yet guarantee consistent exception behavior across platforms,
2404 so the exception part of test_math is run only in verbose mode, and
2405 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002406
2407Internals
2408
2409- PyOS_CheckStack() has been disabled on Win64, where it caused
2410 test_sre to fail.
2411
2412Build issues
2413
2414- Changed compiler flags, so that gcc is always invoked with -Wall and
2415 -Wstrict-prototypes. Users compiling Python with GCC should see
2416 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002417 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002418 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002419
Tim Petersa3a3a032000-11-30 05:22:44 +00002420- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002421
2422Tools and other miscellany
2423
2424- The compiler in Tools/compiler was updated to support the new
2425 language features introduced in 2.0: extended print statement, list
2426 comprehensions, and augmented assignments. The new compiler should
2427 also be backwards compatible with Python 1.5.2; the compiler will
2428 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002429 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002430
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002431What's new in 2.0 release candidate 1 (since beta 2)?
2432=====================================================
2433
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002434What is release candidate 1?
2435
2436We believe that release candidate 1 will fix all known bugs that we
2437intend to fix for the 2.0 final release. This release should be a bit
2438more stable than the previous betas. We would like to see even more
2439widespread testing before the final release, so we are producing this
2440release candidate. The final release will be exactly the same unless
2441any show-stopping (or brown bag) bugs are found by testers of the
2442release candidate.
2443
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002444All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002445to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002446
2447Core language, builtins, and interpreter
2448
2449- A bug that caused crashes when __coerce__ was used with augmented
2450 assignment, e.g. +=, was fixed.
2451
2452- Raise ZeroDivisionError when raising zero to a negative number,
2453 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2454 power operator and the result of math.pow(0.0, -2.0) will vary by
2455 platform. On Linux, it raises a ValueError.
2456
2457- A bug in Unicode string interpolation was fixed that occasionally
2458 caused errors with formats including "%%". For example, the
2459 following expression "%% %s" % u"abc" no longer raises a TypeError.
2460
2461- Compilation of deeply nested expressions raises MemoryError instead
2462 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2463
2464- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2465 rendering them useless. They are now written in binary mode again.
2466
2467Standard library
2468
2469- Keyword arguments are now accepted for most pattern and match object
2470 methods in SRE, the standard regular expression engine.
2471
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002472- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002473 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002474
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002475- Several bugs in the Unicode handling and error handling in _tkinter
2476 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002477
2478- Fix memory management errors in Merge() and Tkapp_Call() routines.
2479
2480- Several changes were made to cStringIO to make it compatible with
2481 the file-like object interface and with StringIO. If operations are
2482 performed on a closed object, an exception is raised. The truncate
2483 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002484 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002485
2486- There were many changes made to the linuxaudiodev module and its
2487 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002488 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002489
2490 Note that this module is named poorly, because it should work
2491 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002492 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002493
2494 The module now raises exceptions when errors occur instead of
2495 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2496 audio) and defines a getptr() method that calls the
2497 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2498
2499- The library_version attribute, introduced in an earlier beta, was
2500 removed because it can not be supported with early versions of the C
2501 readline library, which provides no way to determine the version at
2502 compile-time.
2503
2504- The binascii module is now enabled on Win64.
2505
Tim Peters46446d62000-10-09 21:19:31 +00002506- tokenize.py no longer suffers "recursion depth" errors when parsing
2507 programs with very long string literals.
2508
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002509Internals
2510
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002511- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002512 which is called when the interpreter starts up to determine where
2513 the standard library is installed. These vulnerabilities affect all
2514 previous versions of Python and can be exploited by setting very
2515 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2516 setuid Python script, although use of the wrapper in
2517 Misc/setuid-prog.c will eliminate the vulnerability.
2518
2519- Fixed garbage collection bugs in instance creation that were
2520 triggered when errors occurred during initialization. The solution,
2521 applied in cPickle and in PyInstance_New(), is to call
2522 PyObject_GC_Init() after the initialization of the object's
2523 container attributes is complete.
2524
2525- pyexpat adds definitions of PyModule_AddStringConstant and
2526 PyModule_AddObject if the Python version is less than 2.0, which
2527 provides compatibility with PyXML on Python 1.5.2.
2528
2529- If the platform has a bogus definition for LONG_BIT (the number of
2530 bits in a long), an error will be reported at compile time.
2531
2532- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2533 collection crashes and possibly other, unreported crashes.
2534
2535- Fixed a memory leak in _PyUnicode_Fini().
2536
2537Build issues
2538
2539- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002540 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002541 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002542
2543- The mmap.PAGESIZE constant is now initialized using sysconf when
2544 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2545
2546- The md5 file should now compile on all platforms.
2547
2548- The select module now compiles on platforms that do not define
2549 POLLRDNORM and related constants.
2550
2551- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002552 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002553
Jeremy Hylton10921202000-10-09 18:34:12 +00002554- BeOS: A number of changes were made to the build and installation
2555 process. ar-fake now operates on a directory of object files.
2556 dl_export.h is gone, and its macros now appear on the mwcc command
2557 line during build on PPC BeOS.
2558
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002559- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002560 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002561
2562- Cygwin: Support for shared libraries, Tkinter, and sockets.
2563
2564- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2565
2566Tools and other miscellany
2567
2568- Removed debugging prints from main used with freeze.
2569
Tim Peters46446d62000-10-09 21:19:31 +00002570- IDLE auto-indent no longer crashes when it encounters Unicode
2571 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002572
2573What's new in 2.0 beta 2 (since beta 1)?
2574========================================
2575
2576Core language, builtins, and interpreter
2577
Tim Peters482c0212000-09-26 06:33:09 +00002578- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002579 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002580
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002581- Add -h and -V command line options to print the usage message and
2582 Python version number and exit immediately.
2583
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002584- eval() and exec accept Unicode objects as code parameters.
2585
2586- getattr() and setattr() now also accept Unicode objects for the
2587 attribute name, which are converted to strings using the default
2588 encoding before lookup.
2589
2590- Multiplication on string and Unicode now does proper bounds
2591 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2592 string is too long."
2593
2594- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002595 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002596
Jeremy Hylton1b618592000-09-26 05:32:36 +00002597
2598Standard library and extensions
2599
Guido van Rossum5b08f132001-04-16 02:05:23 +00002600- socket module: the OpenSSL code now adds support for RAND_status()
2601 and EGD (Entropy Gathering Device).
2602
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002603- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002604 argument checking; it still takes no arguments.
2605
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002606- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002607
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002608- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002609
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002610- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002611
2612- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002613 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002614
2615- copy: Copy Unicode objects atomically.
2616
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002617- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002618
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002619- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002620
Fred Drake67233bc2000-09-26 16:40:27 +00002621- dbm: Add get() and setdefault() methods to dbm object. Add constant
2622 `library' to module that names the library used. Added doc strings
2623 and method names to error messages. Uses configure to determine
2624 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2625 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002626
2627- distutils: Update to version 0.9.3.
2628
2629- dl: Add several dl.RTLD_ constants.
2630
2631- fpectl: Now supported on FreeBSD.
2632
2633- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2634 found by the collector will be saved in gc.garbage. This is useful
2635 for debugging a program that creates reference cycles.
2636
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002637- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002638 of HTTP class. Do not close socket on zero-length response. Do not
2639 crash when server sends invalid content-length header.
2640
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002641- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002642
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002643- marshal: When reading a short, sign-extend on platforms where shorts
2644 are bigger than 16 bits. When reading a long, repair the unportable
2645 sign extension that was being done for 64-bit machines. (It assumed
2646 that signed right shift sign-extends.)
2647
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002648- operator: Add contains(), invert(), __invert__() as aliases for
2649 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002651- os: Add support for popen2() and popen3() on all platforms where
2652 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002653
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002654- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002655 clicking on a file in Explorer (or passing the file name to the
2656 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002657
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002658- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002659 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002660
2661- pickle: Now raises ValueError when an invalid pickle that contains
2662 a non-string repr where a string repr was expected. This behavior
2663 matches cPickle.
2664
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002665- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002666
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002667- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002668
2669- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002670 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002671 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002672
2673- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002674 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002675
2676- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002677 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002678 few cycles during startup since the first call to
2679 setdefaultencoding() will initialize the codec registry and the
2680 encodings package.
2681
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002682- socket: Support for size hint in readlines() method of object returned
2683 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002684
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002685- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002686 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002687 is followed by whitespace.
2688
Tim Petersa3a3a032000-11-30 05:22:44 +00002689- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002690
2691- struct: Check ranges for bytes and shorts.
2692
2693- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002694 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002695
2696- Tkinter: Image objects are now guaranteed to have unique ids. Set
2697 event.delta to zero if Tk version doesn't support mousewheel.
2698 Removed some debugging prints.
2699
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002700- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002701
Fred Drake67233bc2000-09-26 16:40:27 +00002702- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002703 which works around a bug in Norton AntiVirus 2000 that leads directly
2704 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002705
2706- xml: New version detection code allows PyXML to override standard
2707 XML package if PyXML version is greater than 0.6.1.
2708
Fred Drake64bb3802000-09-26 16:21:35 +00002709- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2710 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2711 tree only for nodes which are sufficiently interesting to a specific
2712 application. Does not provide the HTML-specific extensions. Still
2713 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002714
Fred Drake64bb3802000-09-26 16:21:35 +00002715- xml.sax: SAX 2 support for Python, including all the handler
2716 interfaces needed to process XML 1.0 compliant XML. Some
2717 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718
Fred Drake64bb3802000-09-26 16:21:35 +00002719- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2720 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002722
Jeremy Hylton1b618592000-09-26 05:32:36 +00002723C API
2724
2725- Add three new convenience functions for module initialization --
2726 PyModule_AddObject(), PyModule_AddIntConstant(), and
2727 PyModule_AddStringConstant().
2728
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002729- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002730 removed and add #error to Python.h if NULL isn't defined after
2731 #include of stdio.h.
2732
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002733- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002734 backwards compatibility (at the source level) with old extensions.
2735
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002736- A wrapper API was added for signal() and sigaction(). Instead of
2737 either function, always use PyOS_getsig() to get a signal handler
2738 and PyOS_setsig() to set one. A new convenience typedef
2739 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002740
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002741- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002742 internal data buffer and size of a string object -- or the default
2743 encoded version of a Unicode object.
2744
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002745- PyString_Size() and PyString_AsString() accept Unicode objects.
2746
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002747- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002748 exists). INT_MAX and LONG_MAX will always be defined, even if
2749 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002750
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002751- PyFloat_FromString takes a second argument, pend, that was
2752 effectively useless. It is now officially useless but preserved for
2753 backwards compatibility. If the pend argument is not NULL, *pend is
2754 set to NULL.
2755
2756- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2757 for the attribute name. See note on getattr() above.
2758
2759- A few bug fixes to argument processing for Unicode.
2760 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2761 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2762 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002763 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002764
2765- Py_BuildValue accepts B format (for bgen-generated code).
2766
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002767
Jeremy Hylton1b618592000-09-26 05:32:36 +00002768Internals
2769
2770- On Unix, fix code for finding Python installation directory so that
2771 it works when argv[0] is a relative path.
2772
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002773- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002774 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002775 rather than by generating a copy of the object.
2776
Tim Peters482c0212000-09-26 06:33:09 +00002777- Several of the internal Unicode tables are much smaller now, and
2778 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779
Jeremy Hylton97693b02000-09-26 17:42:51 +00002780- In the garbage collector: Fixed bug in collection of tuples. Fixed
2781 bug that caused some instances to be removed from the container set
2782 while they were still live. Fixed parsing in gc.set_debug() for
2783 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002784
2785- Fixed refcount problem in instance deallocation that only occurred
2786 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2787
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002788- On Windows, getpythonregpath is now protected against null data in
2789 registry key.
2790
2791- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002792 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002793
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002794
Jeremy Hylton1b618592000-09-26 05:32:36 +00002795Build and platform-specific issues
2796
2797- Better support of GNU Pth via --with-pth configure option.
2798
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002799- Python/C API now properly exposed to dynamically-loaded extension
2800 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002801
2802- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2803 Don't define MS_SYNC to be zero when it is undefined. Added missing
2804 prototypes in posixmodule.c.
2805
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002806- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002807 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002808
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002809- Fix largefile support on older NetBSD systems and OpenBSD by adding
2810 define for TELL64.
2811
2812
2813Tools and other miscellany
2814
2815- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2816
2817- freeze: The modulefinder now works with 2.0 opcodes.
2818
Tim Petersa3a3a032000-11-30 05:22:44 +00002819- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002820 Move hackery of sys.argv until after the Tk instance has been
2821 created, which allows the application-specific Tkinter
2822 initialization to be executed if present; also pass an explicit
2823 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002824
Jeremy Hylton1b618592000-09-26 05:32:36 +00002825
2826What's new in 2.0 beta 1?
2827=========================
2828
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002829Source Incompatibilities
2830------------------------
2831
2832None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2833such as single-argument append(), connect() and bind(), and changes to
2834str(long) and repr(float).
2835
2836
2837Binary Incompatibilities
2838------------------------
2839
2840- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2841with Python 2.0; these extensions will have to be rebuilt for Python
28422.0.
2843
2844- On Windows, attempting to import a third party extension built for
2845Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2846can do about this. Check your PYTHONPATH environment variable!
2847
2848- Python bytecode files (*.pyc and *.pyo) are not compatible between
2849releases.
2850
2851
2852Overview of Changes Since 1.6
2853-----------------------------
2854
2855There are many new modules (including brand new XML support through
2856the xml package, and i18n support through the gettext module); a list
2857of all new modules is included below. Lots of bugs have been fixed.
2858
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002859The process for making major new changes to the language has changed
2860since Python 1.6. Enhancements must now be documented by a Python
2861Enhancement Proposal (PEP) before they can be accepted.
2862
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002863There are several important syntax enhancements, described in more
2864detail below:
2865
2866 - Augmented assignment, e.g. x += 1
2867
2868 - List comprehensions, e.g. [x**2 for x in range(10)]
2869
2870 - Extended import statement, e.g. import Module as Name
2871
2872 - Extended print statement, e.g. print >> file, "Hello"
2873
2874Other important changes:
2875
2876 - Optional collection of cyclical garbage
2877
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002878Python Enhancement Proposal (PEP)
2879---------------------------------
2880
2881PEP stands for Python Enhancement Proposal. A PEP is a design
2882document providing information to the Python community, or describing
2883a new feature for Python. The PEP should provide a concise technical
2884specification of the feature and a rationale for the feature.
2885
2886We intend PEPs to be the primary mechanisms for proposing new
2887features, for collecting community input on an issue, and for
2888documenting the design decisions that have gone into Python. The PEP
2889author is responsible for building consensus within the community and
2890documenting dissenting opinions.
2891
2892The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002893
2894Augmented Assignment
2895--------------------
2896
2897This must have been the most-requested feature of the past years!
2898Eleven new assignment operators were added:
2899
Guido van Rossume905e952000-09-05 12:42:46 +00002900 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002901
2902For example,
2903
2904 A += B
2905
2906is similar to
2907
2908 A = A + B
2909
2910except that A is evaluated only once (relevant when A is something
2911like dict[index].attr).
2912
2913However, if A is a mutable object, A may be modified in place. Thus,
2914if A is a number or a string, A += B has the same effect as A = A+B
2915(except A is only evaluated once); but if a is a list, A += B has the
2916same effect as A.extend(B)!
2917
2918Classes and built-in object types can override the new operators in
2919order to implement the in-place behavior; the not-in-place behavior is
2920used automatically as a fallback when an object doesn't implement the
2921in-place behavior. For classes, the method name is derived from the
2922method name for the corresponding not-in-place operator by inserting
2923an 'i' in front of the name, e.g. __iadd__ implements in-place
2924__add__.
2925
2926Augmented assignment was implemented by Thomas Wouters.
2927
2928
2929List Comprehensions
2930-------------------
2931
2932This is a flexible new notation for lists whose elements are computed
2933from another list (or lists). The simplest form is:
2934
2935 [<expression> for <variable> in <sequence>]
2936
Guido van Rossum56db0952000-09-06 23:34:25 +00002937For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002938This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002939
2940You can also add a condition:
2941
2942 [<expression> for <variable> in <sequence> if <condition>]
2943
2944For example, [w for w in words if w == w.lower()] would yield the list
2945of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002946than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002947
2948You can also have nested for loops and more than one 'if' clause. For
2949example, here's a function that flattens a sequence of sequences::
2950
2951 def flatten(seq):
2952 return [x for subseq in seq for x in subseq]
2953
2954 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2955
2956This prints
2957
2958 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2959
2960List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002961Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002962
2963
2964Extended Import Statement
2965-------------------------
2966
2967Many people have asked for a way to import a module under a different
2968name. This can be accomplished like this:
2969
2970 import foo
2971 bar = foo
2972 del foo
2973
2974but this common idiom gets old quickly. A simple extension of the
2975import statement now allows this to be written as follows:
2976
2977 import foo as bar
2978
2979There's also a variant for 'from ... import':
2980
2981 from foo import bar as spam
2982
2983This also works with packages; e.g. you can write this:
2984
2985 import test.regrtest as regrtest
2986
2987Note that 'as' is not a new keyword -- it is recognized only in this
2988context (this is only possible because the syntax for the import
2989statement doesn't involve expressions).
2990
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002991Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002992
2993
2994Extended Print Statement
2995------------------------
2996
2997Easily the most controversial new feature, this extension to the print
2998statement adds an option to make the output go to a different file
2999than the default sys.stdout.
3000
3001For example, to write an error message to sys.stderr, you can now
3002write:
3003
3004 print >> sys.stderr, "Error: bad dog!"
3005
3006As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003007evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003008
3009 print >> None, "Hello world"
3010
3011is equivalent to
3012
3013 print "Hello world"
3014
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003015Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003016
3017
3018Optional Collection of Cyclical Garbage
3019---------------------------------------
3020
3021Python is now equipped with a garbage collector that can hunt down
3022cyclical references between Python objects. It's no replacement for
3023reference counting; in fact, it depends on the reference counts being
3024correct, and decides that a set of objects belong to a cycle if all
3025their reference counts can be accounted for from their references to
3026each other. This devious scheme was first proposed by Eric Tiedemann,
3027and brought to implementation by Neil Schemenauer.
3028
3029There's a module "gc" that lets you control some parameters of the
3030garbage collection. There's also an option to the configure script
3031that lets you enable or disable the garbage collection. In 2.0b1,
3032it's on by default, so that we (hopefully) can collect decent user
3033experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003034performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003035off by default in the final 2.0 release.
3036
3037
3038Smaller Changes
3039---------------
3040
3041A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3042map(None, seq1, seq2, ...) when the sequences have the same length;
3043i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3044the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003045zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003046
3047sys.version_info is a tuple (major, minor, micro, level, serial).
3048
3049Dictionaries have an odd new method, setdefault(key, default).
3050dict.setdefault(key, default) returns dict[key] if it exists; if not,
3051it sets dict[key] to default and returns that value. Thus:
3052
3053 dict.setdefault(key, []).append(item)
3054
3055does the same work as this common idiom:
3056
3057 if not dict.has_key(key):
3058 dict[key] = []
3059 dict[key].append(item)
3060
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003061There are two new variants of SyntaxError that are raised for
3062indentation-related errors: IndentationError and TabError.
3063
3064Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3065escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003066
3067The limits on the size of expressions and file in Python source code
3068have been raised from 2**16 to 2**32. Previous versions of Python
3069were limited because the maximum argument size the Python VM accepted
3070was 2**16. This limited the size of object constructor expressions,
3071e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3072limit was raised thanks to a patch by Charles Waldman that effectively
3073fixes the problem. It is now much more likely that you will be
3074limited by available memory than by an arbitrary limit in Python.
3075
3076The interpreter's maximum recursion depth can be modified by Python
3077programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3078limit is the maximum number of recursive calls that can be made by
3079Python code. The limit exists to prevent infinite recursion from
3080overflowing the C stack and causing a core dump. The default value is
30811000. The maximum safe value for a particular platform can be found
3082by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003083
3084New Modules and Packages
3085------------------------
3086
3087atexit - for registering functions to be called when Python exits.
3088
3089imputil - Greg Stein's alternative API for writing custom import
3090hooks.
3091
3092pyexpat - an interface to the Expat XML parser, contributed by Paul
3093Prescod.
3094
3095xml - a new package with XML support code organized (so far) in three
3096subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3097would fill a volume. There's a special feature whereby a
3098user-installed package named _xmlplus overrides the standard
3099xmlpackage; this is intended to give the XML SIG a hook to distribute
3100backwards-compatible updates to the standard xml package.
3101
3102webbrowser - a platform-independent API to launch a web browser.
3103
3104
Guido van Rossume905e952000-09-05 12:42:46 +00003105Changed Modules
3106---------------
3107
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003108array -- new methods for array objects: count, extend, index, pop, and
3109remove
3110
3111binascii -- new functions b2a_hex and a2b_hex that convert between
3112binary data and its hex representation
3113
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003114calendar -- Many new functions that support features including control
3115over which day of the week is the first day, returning strings instead
3116of printing them. Also new symbolic constants for days of week,
3117e.g. MONDAY, ..., SUNDAY.
3118
3119cgi -- FieldStorage objects have a getvalue method that works like a
3120dictionary's get method and returns the value attribute of the object.
3121
3122ConfigParser -- The parser object has new methods has_option,
3123remove_section, remove_option, set, and write. They allow the module
3124to be used for writing config files as well as reading them.
3125
3126ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003127optionally support the RFC 959 REST command.
3128
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003129gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003130
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003131httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3132the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003133
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003134locale -- implement getdefaultlocale for Win32 and Macintosh
3135
3136marshal -- no longer dumps core when marshaling deeply nested or
3137recursive data structures
3138
3139os -- new functions isatty, seteuid, setegid, setreuid, setregid
3140
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003141os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3142support under Unix.
3143
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003144os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003145
3146os.path -- fix semantics of os.path.commonprefix
3147
3148smtplib -- support for sending very long messages
3149
3150socket -- new function getfqdn()
3151
3152readline -- new functions to read, write and truncate history files.
3153The readline section of the library reference manual contains an
3154example.
3155
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003156select -- add interface to poll system call
3157
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003158shutil -- new copyfileobj function
3159
3160SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3161HTTP server.
3162
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003163Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003164
3165urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003166e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003167
3168whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003169
3170
3171Obsolete Modules
3172----------------
3173
3174None. However note that 1.6 made a whole slew of modules obsolete:
3175stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3176poly, zmod, strop, util, whatsound.
3177
3178
3179Changed, New, Obsolete Tools
3180----------------------------
3181
Tim Peters8b092332000-09-05 20:15:25 +00003182None.
Guido van Rossume905e952000-09-05 12:42:46 +00003183
3184
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003185C-level Changes
3186---------------
3187
3188Several cleanup jobs were carried out throughout the source code.
3189
3190All C code was converted to ANSI C; we got rid of all uses of the
3191Py_PROTO() macro, which makes the header files a lot more readable.
3192
3193Most of the portability hacks were moved to a new header file,
3194pyport.h; several other new header files were added and some old
3195header files were removed, in an attempt to create a more rational set
3196of header files. (Few of these ever need to be included explicitly;
3197they are all included by Python.h.)
3198
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003199Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003200and Win64, especially for the new Intel Itanium processor. Mick also
3201added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003202
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003203The C APIs to return an object's size have been update to consistently
3204use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3205previous versions, the abstract interfaces used PyXXX_Length and the
3206concrete interfaces used PyXXX_Size. The old names,
3207e.g. PyObject_Length, are still available for backwards compatibility
3208at the API level, but are deprecated.
3209
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003210The PyOS_CheckStack function has been implemented on Windows by
3211Fredrik Lundh. It prevents Python from failing with a stack overflow
3212on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003213
3214The GC changes resulted in creation of two new slots on object,
3215tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003216the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003217
3218The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003219C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003220
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003221PyErr_Format has been updated to automatically calculate the size of
3222the buffer needed to hold the formatted result string. This change
3223prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003224
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003225New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003226
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003227PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3228that are the same as their non-Ex counterparts except they take an
3229extra flag argument that tells them to close the file when done.
3230
3231XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003232
Tim Peters8b092332000-09-05 20:15:25 +00003233
3234Windows Changes
3235---------------
3236
3237New popen2/popen3/peopen4 in os module (see Changed Modules above).
3238
3239os.popen is much more usable on Windows 95 and 98. See Microsoft
3240Knowledge Base article Q150956. The Win9x workaround described there
3241is implemented by the new w9xpopen.exe helper in the root of your
3242Python installation. Note that Python uses this internally; it is not
3243a standalone program.
3244
3245Administrator privileges are no longer required to install Python
3246on Windows NT or Windows 2000. If you have administrator privileges,
3247Python's registry info will be written under HKEY_LOCAL_MACHINE.
3248Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003249under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003250uses of Python, but will prevent some advanced uses from working
3251(for example, running a Python script as an NT service, or possibly
3252from CGI).
3253
3254[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3255installer; instead, it installs the needed Tcl/Tk files directly in the
3256Python directory. If you already have a Tcl/Tk installation, this
3257wastes some disk space (about 4 Megs) but avoids problems with
3258conflicting Tcl/Tk installations, and makes it much easier for Python
3259to ensure that Tcl/Tk can find all its files.
3260
3261[This was new in 1.6] The Windows installer now installs by default in
3262\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3263
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003264
3265Updates to the changes between 1.5.2 and 1.6
3266--------------------------------------------
3267
3268The 1.6 NEWS file can't be changed after the release is done, so here
3269is some late-breaking news:
3270
3271New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3272and changes to getlocale() and setlocale().
3273
3274The new module is now enabled per default.
3275
3276It is not true that the encodings codecs cannot be used for normal
3277strings: the string.encode() (which is also present on 8-bit strings
3278!) allows using them for 8-bit strings too, e.g. to convert files from
3279cp1252 (Windows) to latin-1 or vice-versa.
3280
3281Japanese codecs are available from Tamito KAJIYAMA:
3282http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3283
3284
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003285======================================================================