blob: e4b0bb2bb8ea1acf11d033e5b4e33269575db435 [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
Guido van Rossumc69343b2002-04-12 19:22:48 +00009- Added a new dict method pop(key). This removes and returns the
10 value corresponding to key. [SF patch #539949]
11
Guido van Rossum8ace1ab2002-04-06 01:05:01 +000012- Changed new-style class instantiation so that when C's __new__
13 method returns something that's not a C instance, its __init__ is
14 not called. [SF bug #537450]
15
Guido van Rossum181e41a2002-04-06 00:23:25 +000016- Fixed super() to work correctly with class methods. [SF bug #535444]
17
Guido van Rossum47834462002-04-04 15:21:33 +000018- A new built-in type, bool, has been added, as well as built-in
19 names for its two values, True and False. Comparisons and sundry
20 other operations that return a truth value have been changed to
21 return a bool instead. Read PEP 285 for an explanantion of why this
22 is backward compatible.
23
Guido van Rossum95b62a62002-03-29 01:07:24 +000024- Fixed two bugs reported as SF #535905: under certain conditions,
25 deallocating a deeply nested structure could cause a segfault in the
26 garbage collector, due to interaction with the "trashcan" code;
27 access to the current frame during destruction of a local variable
28 could access a pointer to freed memory.
29
Neil Schemenauer9d50d132002-03-22 17:06:59 +000030- The optional object allocator has been enabled by default.
31
Guido van Rossum8c842552002-03-14 23:05:54 +000032- If you try to pickle an instance of a class that has __slots__ but
33 doesn't define or override __getstate__, a TypeError is now raised.
34 This is done by adding a bozo __getstate__ to the class that always
35 raises TypeError. (Before, this would appear to be pickled, but the
36 state of the slots would be lost.)
37
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000038- PyErr_Display will provide file and line information for all exceptions
39 that have an attribute print_file_and_line, not just SyntaxErrors.
40
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000041- The UTF-8 codec will now encode and decode Unicode surrogates
42 correctly and without raising exceptions for unpaired ones.
43
Neal Norwitz649b7592002-01-01 19:07:13 +000044- file.xreadlines() now raises a ValueError if the file is closed:
45 Previously, an xreadlines object was returned which would raise
46 a ValueError when the xreadlines.next() method was called.
47
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000048- posix.killpg has been added where available.
49
Neal Norwitz0c766a02002-03-27 13:03:09 +000050- sys.exit() inadvertantly allowed more than one argument.
51 An exception will now be raised if more than one argument is used.
52
Tim Petersaf8446f2001-12-21 21:36:50 +000053Extension modules
54
Martin v. Löwis2e64c342002-03-27 18:49:02 +000055- The locale module now exposes the C library's gettext interface.
56
Tim Petersfbf74f22002-03-14 19:06:01 +000057- A security hole ("double free") was found in zlib-1.1.3, a popular
58 third party compression library used by some Python modules. The
59 hole was quickly plugged in zlib-1.1.4, and the Windows build of
60 Python now ships with zlib-1.1.4.
61
Martin v. Löwis688357e2002-04-08 21:28:20 +000062- pwd, grp, and resource return enhanced tuples now, with symbolic
63 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +000064
Martin v. Löwis99866332002-03-01 10:27:01 +000065- array.array is now a type object. A new format character
66 'u' indicates Py_UNICODE arrays. For those, .tounicode and
67 .fromunicode methods are available. Arrays now support __iadd__
68 and __imul__.
69
Neal Norwitze790eae2002-01-01 21:14:12 +000070- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000071 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
72 is called.
73
Tim Petersaf8446f2001-12-21 21:36:50 +000074Library
75
Marc-André Lemburg4179a012002-04-05 12:15:05 +000076- The UTF-16, -LE and -BE now raise a NotImplementedError
77 for all calls to .readline(). Previously, they used to just
78 produce garbage or fail with an encoding error -- UTF-16 is
79 a 2-byte encoding and the C lib's line reading APIs don't
80 work well with these.
81
Martin v. Löwis5c137c22002-03-18 12:44:08 +000082- compileall now supports quiet operation.
83
Martin v. Löwis587c98c2002-03-17 18:37:22 +000084- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
85 connections.
86
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000087- socket module: the SSL support was broken out of the main
88 _socket module C helper and placed into a new _ssl helper
89 which now gets imported by socket.py if available and working.
90
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000091- encodings package: added aliases for all supported IANA character
92 sets
93
Guido van Rossum606fe4e2001-12-28 20:57:14 +000094- ftplib: to safeguard the user's privacy, anonymous login will use
95 "anonymous@" as default password, rather than the real user and host
96 name.
97
Fred Drake36736122002-01-10 13:50:31 +000098- webbrowser: tightened up the command passed to os.system() so that
99 arbitrary shell code can't be executed because a bogus URL was
100 passed in.
101
Tim Peters11bd9942002-02-01 00:52:29 +0000102- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000103 gettext.find an optional all argument. Translations will now fallback
104 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000105
Martin v. Löwis9668b932002-01-12 11:27:42 +0000106- distutils bdist commands now offer a --skip-build option.
107
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000108- warnings.warn now accepts a Warning instance as first argument.
109
Fred Drakefed7e852002-04-04 19:36:15 +0000110- The xml.sax.expatreader.ExpatParser class will no longer create
111 circular references by using itself as the locator that gets passed
112 to the content handler implementation. [SF bug #535474]
113
Tim Petersaf8446f2001-12-21 21:36:50 +0000114Tools/Demos
115
Marc-André Lemburg46260092002-04-04 16:17:11 +0000116- freeze.py now produces binaries which can import shared modules,
117 unlike before when this failed due to missing symbol exports in
118 the generated binary.
119
Tim Petersaf8446f2001-12-21 21:36:50 +0000120Build
121
Martin v. Löwis1142de32002-03-29 16:28:31 +0000122- On Unix, a shared libpython2.3.so can be created with --enable-shared.
123
Tim Peters8deda702002-03-30 10:06:07 +0000124- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
125 preprocessor symbols were eliminated. The internal decisions they
126 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000127
Tim Petersaf8446f2001-12-21 21:36:50 +0000128C API
129
Guido van Rossum0986d822002-04-08 01:38:42 +0000130- A type can now inherit its metatype from its base type. Previously,
131 when PyType_Ready() was called, if ob_type was found to be NULL, it
132 was always set to &PyType_Type; now it is set to base->ob_type,
133 where base is tp_base, defaulting to &PyObject_Type.
134
135- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
136
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000137- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
138 functions will be allocated using pymalloc if it is enabled. These
139 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
140 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
141 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
142 PyCore_* family of APIs have been removed.
143
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000144- The "u#" parser marker will now pass through Unicode object as-is
145 without going through the buffer API.
146
Martin v. Löwis7198a522002-01-01 19:59:11 +0000147- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
148
Tim Peters10a3bb52001-12-25 19:07:38 +0000149- An old #define of ANY as void has been removed from pyport.h. This
150 hasn't been used since Python's pre-ANSI days, and the #define has
151 been marked as obsolete since then. SF bug 495548 says it created
152 conflicts with other packages, so keeping it around wasn't harmless.
153
Tim Petersaf8446f2001-12-21 21:36:50 +0000154- Because Python's magic number scheme broke on January 1st, we decided
155 to stop Python development. Thanks for all the fish!
156
Tim Petersfb05db22002-03-11 00:24:00 +0000157- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000158 scheme to a new one. See Python/import.c for details.
159
Tim Petersaf8446f2001-12-21 21:36:50 +0000160New platforms
161
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000162- GNU/Hurd is now supported.
163
Tim Petersaf8446f2001-12-21 21:36:50 +0000164Tests
165
166Windows
167
Guido van Rossum181e41a2002-04-06 00:23:25 +0000168- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
169
Tim Peters33187922002-04-04 20:02:04 +0000170- The installer now installs Start menu shortcuts under (the local
171 equivalent of) "All Users" when doing an Admin install.
172
Tim Petersfb05db22002-03-11 00:24:00 +0000173- file.truncate([newsize]) now works on Windows for all newsize values.
174 It used to fail if newsize didn't fit in 32 bits, reflecting a
175 limitation of MS _chsize (which is no longer used).
176
Tim Petersab034fa2002-02-01 11:27:43 +0000177- os.waitpid() is now implemented for Windows, and can be used to block
178 until a specified process exits. This is similar to, but not exactly
179 the same as, os.waitpid() on POSIX systems. If you're waiting for
180 a specific process whose pid was obtained from one of the spawn()
181 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000182 See the docs for details. The docs were changed to clarify that
183 spawn functions return, and waitpid requires, a process handle on
184 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000185
Tim Peters11bd9942002-02-01 00:52:29 +0000186- New tempfile.TemporaryFile implementation for Windows: this doesn't
187 need a TemproraryFileWrapper wrapper anymore, and should be immune
188 to a nasty problem: before 2.3, if you got a temp file on Windows, it
189 got wrapped in an object whose close() method first closed the
190 underlying file, then deleted the file. This usually worked fine.
191 However, the spawn family of functions on Windows create (at a low C
192 level) the same set of open files in the spawned process Q as were
193 open in the spawning process P. If a temp file f was among them, then
194 doing f.close() in P first closed P's C-level file handle on f, but Q's
195 C-level file handle on f remained open, so the attempt in P to delete f
196 blew up with a "Permission denied" error (Windows doesn't allow
197 deleting open files). This was surprising, subtle, and difficult to
198 work around.
199
200- The os module now exports all the symbolic constants usable with the
201 low-level os.open() on Windows: the new constants in 2.3 are
202 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
203 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
204 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
205 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
206 (so specify both if you want both; note that neither is useful unless
207 specified with O_CREAT too).
208
Tim Petersaf8446f2001-12-21 21:36:50 +0000209Mac
210
211
Tim Peters909c0912001-12-14 23:16:18 +0000212What's New in Python 2.2 final?
213Release date: 21-Dec-2001
214===============================
215
216Type/class unification and new-style classes
217
Barry Warsaw52acb492001-12-21 20:04:22 +0000218- pickle.py, cPickle: allow pickling instances of new-style classes
219 with a custom metaclass.
220
Tim Peters909c0912001-12-14 23:16:18 +0000221Core and builtins
222
Barry Warsaw52acb492001-12-21 20:04:22 +0000223- weakref proxy object: when comparing, unwrap both arguments if both
224 are proxies.
225
Tim Peters909c0912001-12-14 23:16:18 +0000226Extension modules
227
Barry Warsaw52acb492001-12-21 20:04:22 +0000228- binascii.b2a_base64(): fix a potential buffer overrun when encoding
229 very short strings.
230
231- cPickle: the obscure "fast" mode was suspected of causing stack
232 overflows on the Mac. Hopefully fixed this by setting the recursion
233 limit much smaller. If the limit is too low (it only affects
234 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
235 when compiling cPickle.c (or in pyconfig.h).
236
Tim Peters909c0912001-12-14 23:16:18 +0000237Library
238
Barry Warsaw52acb492001-12-21 20:04:22 +0000239- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
240 close or delete time).
241
242- rfc822.py: fixed a bug where the address '<>' was converted to None
243 instead of an empty string (also fixes the email.Utils module).
244
245- xmlrpclib.py: version 1.0.0; uses precision for doubles.
246
247- test suite: the pickle and cPickle tests were not executing any code
248 when run from the standard regresssion test.
249
Tim Peters909c0912001-12-14 23:16:18 +0000250Tools/Demos
251
252Build
253
254C API
255
256New platforms
257
258Tests
259
260Windows
261
Barry Warsaw52acb492001-12-21 20:04:22 +0000262- distutils package: fixed broken Windows installers (bdist_wininst).
263
264- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
265 instances are deleted at process exit time.
266
267- socket.py: prevent mysterious warnings when socket instances are
268 deleted at process exit time.
269
270- posixmodule.c: fix a Windows crash with stat() of a filename ending
271 in backslash.
272
Tim Peters909c0912001-12-14 23:16:18 +0000273Mac
274
Barry Warsaw52acb492001-12-21 20:04:22 +0000275- The Carbon toolbox modules have been upgraded to Universal Headers
276 3.4, and experimental CoreGraphics and CarbonEvents modules have
277 been added. All only for framework-enabled MacOSX.
278
Tim Peters909c0912001-12-14 23:16:18 +0000279
Tim Peters6272dfd2001-12-13 19:34:00 +0000280What's New in Python 2.2c1?
281Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000282===========================
283
284Type/class unification and new-style classes
285
Barry Warsaw06557452001-12-14 20:47:12 +0000286- Guido's tutorial introduction to the new type/class features has
287 been extensively updated. See
288
289 http://www.python.org/2.2/descrintro.html
290
291 That remains the primary documentation in this area.
292
Guido van Rossum33bab012001-12-05 22:45:48 +0000293- Fixed a leak: instance variables declared with __slots__ were never
294 deleted!
295
Guido van Rossum4b800852001-12-03 00:54:52 +0000296- The "delete attribute" method of descriptor objects is called
297 __delete__, not __del__. In previous releases, it was mistakenly
298 called __del__, which created an unfortunate overloading condition
299 with finalizers. (The "get attribute" and "set attribute" methods
300 are still called __get__ and __set__, respectively.)
301
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000302- Some subtle issues with the super built-in were fixed:
303
304 (a) When super itself is subclassed, its __get__ method would still
305 return an instance of the base class (i.e., of super).
306
307 (b) super(C, C()).__class__ would return C rather than super. This
308 is confusing. To fix this, I decided to change the semantics of
309 super so that it only applies to code attributes, not to data
310 attributes. After all, overriding data attributes is not
311 supported anyway.
312
313 (c) The __get__ method didn't check whether the argument was an
314 instance of the type used in creation of the super instance.
315
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000316- Previously, hash() of an instance of a subclass of a mutable type
317 (list or dictionary) would return some value, rather than raising
318 TypeError. This has been fixed. Also, directly calling
319 dict.__hash__ and list.__hash__ now raises the same TypeError
320 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000321
Guido van Rossumd331cb52001-12-05 19:46:42 +0000322- New-style objects now support deleting their __dict__. This is for
323 all intents and purposes equivalent to assigning a brand new empty
324 dictionary, but saves space if the object is not used further.
325
Tim Petersb3c9af12001-11-17 00:21:57 +0000326Core and builtins
327
Tim Peters3caca232001-12-06 06:23:26 +0000328- -Qnew now works as documented in PEP 238: when -Qnew is passed on
329 the command line, all occurrences of "/" use true division instead
330 of classic division. See the PEP for details. Note that "all"
331 means all instances in library and 3rd-party modules, as well as in
332 your own code. As the PEP says, -Qnew is intended for use only in
333 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000334 Note that test_coercion.py in the standard Python test suite fails
335 under -Qnew; this is expected, and won't be repaired until true
336 division becomes the default (in the meantime, test_coercion is
337 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000338
Fred Drake6c01e252001-12-14 17:08:12 +0000339- complex() now only allows the first argument to be a string
340 argument, and raises TypeError if either the second arg is a string
341 or if the second arg is specified when the first is a string.
342
Tim Petersb3c9af12001-11-17 00:21:57 +0000343Extension modules
344
Martin v. Löwis560da622001-11-24 09:24:51 +0000345- gc.get_referents was renamed to gc.get_referrers.
346
Tim Petersb3c9af12001-11-17 00:21:57 +0000347Library
348
Tim Peters25059d32001-12-07 20:35:43 +0000349- Functions in the os.spawn() family now release the global interpreter
350 lock around calling the platform spawn. They should always have done
351 this, but did not before 2.2c1. Multithreaded programs calling
352 an os.spawn function with P_WAIT will no longer block all Python threads
353 until the spawned program completes. It's possible that some programs
354 relies on blocking, although more likely by accident than by design.
355
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000356- webbrowser defaults to netscape.exe on OS/2 now.
357
Martin v. Löwis652e1912001-11-25 14:50:56 +0000358- Tix.ResizeHandle exposes detach_widget, hide, and show.
359
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000360- The charset alias windows_1252 has been added.
361
Barry Warsaw06557452001-12-14 20:47:12 +0000362- types.StringTypes is a tuple containing the defined string types;
363 usually this will be (str, unicode), but if Python was compiled
364 without Unicode support it will be just (str,).
365
366- The pulldom and minidom modules were synchronized to PyXML.
367
Tim Petersb3c9af12001-11-17 00:21:57 +0000368Tools/Demos
369
Barry Warsaw06557452001-12-14 20:47:12 +0000370- A new script called Tools/scripts/google.py was added, which fires
371 off a search on Google.
372
Tim Petersb3c9af12001-11-17 00:21:57 +0000373Build
374
Barry Warsaw06557452001-12-14 20:47:12 +0000375- Note that release builds of Python should arrange to define the
376 preprocessor symbol NDEBUG on the command line (or equivalent).
377 In the 2.2 pre-release series we tried to define this by magic in
378 Python.h instead, but it proved to cause problems for extension
379 authors. The Unix, Windows and Mac builds now all define NDEBUG in
380 release builds via cmdline (or equivalent) instead. Ports to
381 other platforms should do likewise.
382
Jack Jansen1999ef42001-12-06 21:47:20 +0000383- It is no longer necessary to use --with-suffix when building on a
384 case-insensitive file system (such as Mac OS X HFS+). In the build
385 directory an extension is used, but not in the installed python.
386
Tim Petersb3c9af12001-11-17 00:21:57 +0000387C API
388
Tim Petersf582b822001-12-11 18:51:08 +0000389- New function PyDict_MergeFromSeq2() exposes the builtin dict
390 constructor's logic for updating a dictionary from an iterable object
391 producing key-value pairs.
392
Tim Peterscffed4b2001-11-29 03:26:37 +0000393- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000394 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000395 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
396 dump core in some bad cases. This has been repaired. As a result,
397 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
398 previously went unchallenged.
399
Tim Petersb3c9af12001-11-17 00:21:57 +0000400New platforms
401
402Tests
403
404Windows
405
406Mac
407
Jack Jansenffa260f2001-12-06 21:14:00 +0000408- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
409 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000410
Barry Warsaw06557452001-12-14 20:47:12 +0000411- Changed logic for finding python home in Mac OS X framework Pythons.
412 Now sys.executable points to the executable again, in stead of to
413 the shared library. The latter is used only for locating the python
414 home.
415
416
Tim Peters84362bc2001-10-19 17:55:30 +0000417What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000418Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000419===========================
420
421Type/class unification and new-style classes
422
Guido van Rossum3d27df02001-11-15 20:27:54 +0000423- Multiple inheritance mixing new-style and classic classes in the
424 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000425
426 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000427 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000428
429 The MRO (method resolution order) for each base class is respected
430 according to its kind, but the MRO for the derived class is computed
431 using new-style MRO rules if any base clase is a new-style class.
432 This needs to be documented.
433
Tim Petersa427a2b2001-10-29 22:25:45 +0000434- The new builtin dictionary() constructor, and dictionary type, have
435 been renamed to dict. This reflects a decade of common usage.
436
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000437- dict() now accepts an iterable object producing 2-sequences. For
438 example, dict(d.items()) == d for any dictionary d. The argument,
439 and the elements of the argument, can be any iterable objects.
440
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000441- New-style classes can now have a __del__ method, which is called
442 when the instance is deleted (just like for classic classes).
443
Guido van Rossum12d955c2001-10-26 14:56:06 +0000444- Assignment to object.__dict__ is now possible, for objects that are
445 instances of new-style classes that have a __dict__ (unless the base
446 class forbids it).
447
Guido van Rossumc8e56452001-10-22 00:43:43 +0000448- Methods of built-in types now properly check for keyword arguments
449 (formerly these were silently ignored). The only built-in methods
450 that take keyword arguments are __call__, __init__ and __new__.
451
Guido van Rossum86443212001-10-27 22:28:54 +0000452- The socket function has been converted to a type; see below.
453
Tim Peters84362bc2001-10-19 17:55:30 +0000454Core and builtins
455
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000456- Assignment to __debug__ raises SyntaxError at compile-time. This
457 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000458 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000459
Guido van Rossum12d955c2001-10-26 14:56:06 +0000460- Clarified the error messages for unsupported operands to an operator
461 (like 1 + '').
462
Tim Peters84362bc2001-10-19 17:55:30 +0000463Extension modules
464
Tim Peters5ebfd362001-11-13 23:11:19 +0000465- mmap has a new keyword argument, "access", allowing a uniform way for
466 both Windows and Unix users to create read-only, write-through and
467 copy-on-write memory mappings. This was previously possible only on
468 Unix. A new keyword argument was required to support this in a
469 uniform way because the mmap() signuatures had diverged across
470 platforms. Thanks to Jay T Miller for repairing this!
471
Tim Peters169ded02001-11-03 19:57:21 +0000472- By default, the gc.garbage list now contains only those instances in
473 unreachable cycles that have __del__ methods; in 2.1 it contained all
474 instances in unreachable cycles. "Instances" here has been generalized
475 to include instances of both new-style and old-style classes.
476
Guido van Rossum12d955c2001-10-26 14:56:06 +0000477- The socket module defines a new method for socket objects,
478 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000479 send() until all data has been sent. Also, the socket function has
480 been converted to a subclassable type, like list and tuple (etc.)
481 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000482
483- Various bugfixes to the curses module. There is now a test suite
484 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000485
Guido van Rossum692adf12001-10-30 03:03:03 +0000486- binascii.b2a_base64 no longer places an arbitrary restriction of 57
487 bytes on its input.
488
Tim Peters84362bc2001-10-19 17:55:30 +0000489Library
490
Tim Peters5ebfd362001-11-13 23:11:19 +0000491- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000492 convenience function.
493
Tim Peters75335872001-11-03 19:35:43 +0000494- Symbolic group names in regular expressions must be unique. For
495 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
496 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000497 Python 2.2 detects this error at regexp compilation time;
498 previously, the error went undetected, and results were
499 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
500 pattern.subn() methods have been rewritten in C. Also, an
501 experimental function/method finditer() has been added, which works
502 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000503
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000504- Tix exposes more commands through the classes DirSelectBox,
505 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
506 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
507 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
508
Tim Peters98791af2001-10-23 01:59:54 +0000509- Traceback objects are now scanned by cyclic garbage collection, so
510 cycles created by casual use of sys.exc_info() no longer cause
511 permanent memory leaks (provided garbage collection is enabled).
512
Guido van Rossum49192142001-10-24 20:51:44 +0000513- os.extsep -- a new variable needed by the RISCOS support. It is the
514 separator used by extensions, and is '.' on all platforms except
515 RISCOS, where it is '/'. There is no need to use this variable
516 unless you have a masochistic desire to port your code to RISCOS.
517
Barry Warsaw012852b2001-11-16 16:17:27 +0000518- mimetypes.py has optional support for non-standard, but commonly
519 found types. guess_type() and guess_extension() now accept an
520 optional `strict' flag, defaulting to true, which controls whether
521 recognize non-standard types or not. A few non-standard types we
522 know about have been added. Also, when run as a script, there are
523 new -l and -e options.
524
525- statcache is now deprecated.
526
527- email.Utils.formatdate() now produces the preferred RFC 2822 style
528 dates with numeric timezones (it used to produce obsolete dates
529 hard coded to "GMT" timezone). An optional `localtime' flag is
530 added to produce dates in the local timezone, with daylight savings
531 time properly taken into account.
532
533- In pickle and cPickle, instead of masking errors in load() by
534 transforming them into SystemError, we let the original exception
535 propagate out. Also, implement support for __safe_for_unpickling__
536 in pickle, as it already was supported in cPickle.
537
Tim Peters84362bc2001-10-19 17:55:30 +0000538Tools/Demos
539
540Build
541
Barry Warsaw012852b2001-11-16 16:17:27 +0000542- The dbm module is built using libdb1 if available. The bsddb module
543 is built with libdb3 if available.
544
545- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
546
Tim Peters84362bc2001-10-19 17:55:30 +0000547C API
548
Tim Peters1fc240e2001-10-26 05:06:50 +0000549- New function PySequence_Fast_GET_SIZE() returns the size of a non-
550 NULL result from PySequence_Fast(), more quickly than calling
551 PySequence_Size().
552
Barry Warsaw012852b2001-11-16 16:17:27 +0000553- New argument unpacking function PyArg_UnpackTuple() added.
554
555- New functions PyObject_CallFunctionObjArgs() and
556 PyObject_CallMethodObjArgs() have been added to make it more
557 convenient and efficient to call functions and methods from C.
558
559- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
560 possible that this will propagate errors it didn't before.
561
562- New function PyObject_CheckReadBuffer(), which returns true if its
563 argument supports the single-segment readable buffer interface.
564
Tim Peters84362bc2001-10-19 17:55:30 +0000565New platforms
566
Guido van Rossum86443212001-10-27 22:28:54 +0000567- We've finally confirmed that this release builds on HP-UX 11.00,
568 *with* threads, and passes the test suite.
569
Tim Peters7a33d8b2001-11-05 02:51:07 +0000570- Thanks to a series of patches from Michael Muller, Python may build
571 again under OS/2 Visual Age C++.
572
Guido van Rossum49192142001-10-24 20:51:44 +0000573- Updated RISCOS port by Dietmar Schwertberger.
574
Tim Peters84362bc2001-10-19 17:55:30 +0000575Tests
576
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000577- Added a test script for the curses module. It isn't run automatically;
578 regrtest.py must be run with '-u curses' to enable it.
579
Tim Peters84362bc2001-10-19 17:55:30 +0000580Windows
581
Barry Warsaw012852b2001-11-16 16:17:27 +0000582Mac
583
584- PythonScript has been moved to unsupported and is slated to be
585 removed completely in the next release.
586
587- It should now be possible to build applets that work on both OS9 and
588 OSX.
589
590- The core is now linked with CoreServices not Carbon; as a side
591 result, default 8bit encoding on OSX is now ASCII.
592
593- Python should now build on OSX 10.1.1
594
Tim Peters84362bc2001-10-19 17:55:30 +0000595
Tim Petersabf925f2001-09-28 21:53:42 +0000596What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000597Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000598===========================
599
600Type/class unification and new-style classes
601
Guido van Rossum687ae002001-10-15 22:03:32 +0000602- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000603 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000604 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000605 remains: the __dict__ of a new-style class is a read-only proxy; you
606 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000607 __defined__ attribute of new-style types no longer exists, for lack
608 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000609 future a __cache__ may be resurrected with a similar function, if I
610 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000611
Tim Peters1c9ca872001-10-04 06:43:12 +0000612- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
613 always returned None, even when there was a class docstring).
614
615- doctest now finds and runs docstrings attached to new-style classes,
616 class methods, static methods, and properties.
617
Guido van Rossum9074ef62001-10-16 21:34:49 +0000618Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000619
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000620- A very subtle syntactical pitfall in list comprehensions was fixed.
621 For example: [a+b for a in 'abc', for b in 'def']. The comma in
622 this example is a mistake. Previously, this would silently let 'a'
623 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
624 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
625 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
626 Note that [a for a in <singleton>] is a convoluted way to say
627 [<singleton>] anyway, so it's not like any expressiveness is lost.
628
Guido van Rossum9074ef62001-10-16 21:34:49 +0000629- getattr(obj, name, default) now only catches AttributeError, as
630 documented, rather than returning the default value for all
631 exceptions (which could mask bugs in a __getattr__ hook, for
632 example).
633
Fred Drakecb7a6b52001-10-22 18:41:51 +0000634- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000635 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000636 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000637 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000638
Guido van Rossum1c486092001-10-19 02:05:35 +0000639- unicode(obj) now behaves more like str(obj), accepting arbitrary
640 objects, and calling a __unicode__ method if it exists.
641 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000642 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000643
Barry Warsawf6fb1712001-10-19 05:35:40 +0000644- isinstance() now allows any object as the first argument and a
645 class, a type or something with a __bases__ tuple attribute for the
646 second argument. The second argument may also be a tuple of a
647 class, type, or something with __bases__, in which case isinstance()
648 will return true if the first argument is an instance of any of the
649 things contained in the second argument tuple. E.g.
650
651 isinstance(x, (A, B))
652
653 returns true if x is an instance of A or B.
654
Guido van Rossum9074ef62001-10-16 21:34:49 +0000655Extension modules
656
657- thread.start_new_thread() now returns the thread ID (previously None).
658
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000659- binascii has now two quopri support functions, a2b_qp and b2a_qp.
660
Guido van Rossumc524d952001-10-19 01:31:59 +0000661- readline now supports setting the startup_hook and the
662 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000663
Guido van Rossumc524d952001-10-19 01:31:59 +0000664- os and posix supports chroot(), setgroups() and unsetenv() where
665 available. The stat(), fstat(), statvfs() and fstatvfs() functions
666 now return "pseudo-sequences" -- the various fields can now be
667 accessed as attributes (e.g. os.stat("/").st_mtime) but for
668 backwards compatibility they also behave as a fixed-length sequence.
669 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000670 attributes.
671
672- time: localtime(), gmtime() and strptime() now return a
673 pseudo-sequence similar to the os.stat() return value, with
674 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000675
Guido van Rossum9074ef62001-10-16 21:34:49 +0000676- Decompression objects in the zlib module now accept an optional
677 second parameter to decompress() that specifies the maximum amount
678 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000679
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000680- optional SSL support in the socket module now exports OpenSSL
681 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
682 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000683 automatically seed its PRNG. Also, the keyfile and certfile
684 arguments to socket.ssl() are now optional.
685
686- posixmodule (and by extension, the os module on POSIX platforms) now
687 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000688
Guido van Rossum9074ef62001-10-16 21:34:49 +0000689Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000690
Tim Peters7402f792001-10-02 03:53:41 +0000691- doctest now excludes functions and classes not defined by the module
692 being tested, thanks to Tim Hochberg.
693
Fred Drakecb7a6b52001-10-22 18:41:51 +0000694- HotShot, a new profiler implemented using a C-based callback, has
695 been added. This substantially reduces the overhead of profiling,
696 but it is still quite preliminary. Support modules and
697 documentation will be added in upcoming releases (before 2.2 final).
698
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000699- profile now produces correct output in situations where an exception
700 raised in Python is cleared by C code (e.g. hasattr()). This used
701 to cause wrong output, including spurious claims of recursive
702 functions and attribution of time spent to the wrong function.
703
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000704 The code and documentation for the derived OldProfile and HotProfile
705 profiling classes was removed. The code hasn't worked for years (if
706 you tried to use them, they raised exceptions). OldProfile
707 intended to reproduce the behavior of the profiler Python used more
708 than 7 years ago, and isn't interesting anymore. HotProfile intended
709 to provide a faster profiler (but producing less information), and
710 that's a worthy goal we intend to meet via a different approach (but
711 without losing information).
712
Tim Peterscce092d2001-10-09 05:31:56 +0000713- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000714 a much better system-specific calibration constant. The constant can
715 now be specified in an instance constructor, or as a Profile class or
716 instance variable, instead of by editing profile.py's source code.
717 Calibration must still be done manually (see the docs for the profile
718 module).
719
720 Note that Profile.calibrate() must be overriden by subclasses.
721 Improving the accuracy required exploiting detailed knowledge of
722 profiler internals; the earlier method abstracted away the details
723 and measured a simplified model instead, but consequently computed
724 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000725
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000726- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000727 which indicates whether output is intended for the header 'Q'
728 encoding.
729
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000730- The SocketServer.ThreadingMixIn class now closes the request after
731 finish_request() returns. (Not when it errors out though.)
732
Barry Warsawf6fb1712001-10-19 05:35:40 +0000733- The nntplib module's NNTP.body() method has grown a `file' argument
734 to allow saving the message body to a file.
735
736- The email package has added a class email.Parser.HeaderParser which
737 only parses headers and does not recurse into the message's body.
738 Also, the module/class MIMEAudio has been added for representing
739 audio data (contributed by Anthony Baxter).
740
741- ftplib should be able to handle files > 2GB.
742
743- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
744 ON, and OFF.
745
Fred Drakecb7a6b52001-10-22 18:41:51 +0000746- xml.dom.minidom NodeList objects now support the length attribute
747 and item() method as required by the DOM specifications.
748
Guido van Rossumed554f62001-10-02 23:15:37 +0000749Tools/Demos
750
751- Demo/dns was removed. It no longer serves any purpose; a package
752 derived from it is now maintained by Anthony Baxter, see
753 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000754
Barry Warsawf6fb1712001-10-19 05:35:40 +0000755- The freeze tool has been made more robust, and two new options have
756 been added: -X and -E.
757
Tim Petersabf925f2001-09-28 21:53:42 +0000758Build
759
Barry Warsawf6fb1712001-10-19 05:35:40 +0000760- configure will use CXX in LINKCC if CXX is used to build main() and
761 the system requires to link a C++ main using the C++ compiler.
762
Tim Petersabf925f2001-09-28 21:53:42 +0000763C API
764
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000765- The documentation for the tp_compare slot is updated to require that
766 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
767 not correct. This is not yet enforced but will be enforced in
768 Python 2.3; even later, we may use -2 to indicate errors and +2 for
769 "NotImplemented". Right now, -1 should be used for an error return.
770
Tim Petersd38b1c72001-09-30 05:09:37 +0000771- PyLong_AsLongLong() now accepts int (as well as long) arguments.
772 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
773 as long) arguments.
774
Guido van Rossum3c288632001-10-16 21:13:49 +0000775- PyThread_start_new_thread() now returns a long int giving the thread
776 ID, if one can be calculated; it returns -1 for error, 0 if no
777 thread ID is calculated (this is an incompatible change, but only
778 the thread module used this API). This code has only really been
779 tested on Linux and Windows; other platforms please beware (and
780 report any bugs or strange behavior).
781
Guido van Rossum1c486092001-10-19 02:05:35 +0000782- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
783 input.
784
Tim Petersabf925f2001-09-28 21:53:42 +0000785New platforms
786
787Tests
788
789Windows
790
Tim Peters04cf1d32001-10-09 22:39:40 +0000791- Installer: If you install IDLE, and don't disable file-extension
792 registration, a new "Edit with IDLE" context (right-click) menu entry
793 is created for .py and .pyw files.
794
Tim Peters1ce3cf72001-10-01 17:58:40 +0000795- The signal module now supports SIGBREAK on Windows, thanks to Steven
796 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
797 action remains to call Win32 ExitProcess(). This can be changed via
798 signal.signal(). For example:
799
800 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
801 # (SIGINT) behavior.
802 import signal
803 signal.signal(signal.SIGBREAK,
804 signal.default_int_handler)
805
806 try:
807 while 1:
808 pass
809 except KeyboardInterrupt:
810 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
811 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
812 # program without the possibility for any Python-level cleanup).
813 print "Clean exit"
814
Tim Petersabf925f2001-09-28 21:53:42 +0000815
Tim Petersb07352e2001-09-08 01:25:47 +0000816What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000817Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000818===========================
819
Guido van Rossum808eea72001-09-25 04:15:41 +0000820Type/class unification and new-style classes
821
822- pydoc and inspect are now aware of new-style classes;
823 e.g. help(list) at the interactive prompt now shows proper
824 documentation for all operations on list objects.
825
826- Applications using Jim Fulton's ExtensionClass module can now safely
827 be used with Python 2.2. In particular, Zope 2.4.1 now works with
828 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
829 examples also work again. It is hoped that Gtk and Boost also work
830 with 2.2a4 and beyond. (If you can confirm this, please write
831 webmaster@python.org; if there are still problems, please open a bug
832 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000833
Tim Peters66c1a522001-09-24 21:17:50 +0000834- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
835 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
836 in the constructed property object. fget, fset and fdel weren't
837 discoverable from Python in 2.2a3. __doc__ is new, and allows to
838 associate a docstring with a property.
839
Guido van Rossum808eea72001-09-25 04:15:41 +0000840- Comparison overloading is now more completely implemented. For
841 example, a str subclass instance can properly be compared to a str
842 instance, and it can properly overload comparison. Ditto for most
843 other built-in object types.
844
845- The repr() of new-style classes has changed; instead of <type
846 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
847 *except* for built-in types, which are still rendered as <type
848 'Foo'> (to avoid upsetting existing code that might parse or
849 otherwise rely on repr() of certain type objects).
850
851- The repr() of new-style objects is now always <Foo object at XXX>;
852 previously, it was sometimes <Foo instance at XXX>.
853
854- For new-style classes, what was previously called __getattr__ is now
855 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000856 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000857 one in classic classes is defined which is called only if regular
858 attribute access raises AttributeError; to catch *all* attribute
859 access, you can use __getattribute__ (for new-style classes). If
860 both are defined, __getattribute__ is called first, and if it raises
861 AttributeError, __getattr__ is called.
862
863- The __class__ attribute of new-style objects can be assigned to.
864 The new class must have the same C-level object layout as the old
865 class.
866
867- The builtin file type can be subclassed now. In the usual pattern,
868 "file" is the name of the builtin type, and file() is a new builtin
869 constructor, with the same signature as the builtin open() function.
870 file() is now the preferred way to open a file.
871
872- Previously, __new__ would only see sequential arguments passed to
873 the type in a constructor call; __init__ would see both sequential
874 and keyword arguments. This made no sense whatsoever any more, so
875 now both __new__ and __init__ see all arguments.
876
877- Previously, hash() applied to an instance of a subclass of str or
878 unicode always returned 0. This has been repaired.
879
880- Previously, an operation on an instance of a subclass of an
881 immutable type (int, long, float, complex, tuple, str, unicode),
882 where the subtype didn't override the operation (and so the
883 operation was handled by the builtin type), could return that
884 instance instead a value of the base type. For example, if s was of
885 a str sublass type, s[:] returned s as-is. Now it returns a str
886 with the same value as s.
887
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000888- Provisional support for pickling new-style objects has been added.
889
Guido van Rossum808eea72001-09-25 04:15:41 +0000890Core
891
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000892- file.writelines() now accepts any iterable object producing strings.
893
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000894- PyUnicode_FromEncodedObject() now works very much like
895 PyObject_Str(obj) in that it tries to use __str__/tp_str
896 on the object if the object is not a string or buffer. This
897 makes unicode() behave like str() when applied to non-string/buffer
898 objects.
899
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000900- PyFile_WriteObject now passes Unicode objects to the file's write
901 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000902 of a print statement must support Unicode objects, i.e. they must
903 at least convert them into ASCII strings.
904
Guido van Rossum624c8af2001-09-18 15:21:04 +0000905- Thread scheduling on Solaris should be improved; it is no longer
906 necessary to insert a small sleep at the start of a thread in order
907 to let other runnable threads be scheduled.
908
Tim Petersb07352e2001-09-08 01:25:47 +0000909Library
910
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000911- StringIO.StringIO instances and cStringIO.StringIO instances support
912 read character buffer compatible objects for their .write() methods.
913 These objects are converted to strings and then handled as such
914 by the instances.
915
Barry Warsaw2f600732001-09-24 04:28:10 +0000916- The "email" package has been added. This is basically a port of the
917 mimelib package <http://sf.net/projects/mimelib> with API changes
918 and some implementations updated to use iterators and generators.
919
Tim Peters8a9c2842001-09-22 21:30:22 +0000920- difflib.ndiff() and difflib.Differ.compare() are generators now. This
921 restores the ability of Tools/scripts/ndiff.py to start producing output
922 before the entire comparison is complete.
923
Barry Warsaw58b072d2001-09-22 04:44:21 +0000924- StringIO.StringIO instances and cStringIO.StringIO instances support
925 iteration just like file objects (i.e. their .readline() method is
926 called for each iteration until it returns an empty string).
927
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000928- The codecs module has grown four new helper APIs to access
929 builtin codecs: getencoder(), getdecoder(), getreader(),
930 getwriter().
931
Guido van Rossum624c8af2001-09-18 15:21:04 +0000932- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
933 simplifies writing XML RPC servers.
934
Barry Warsaw647d5e82001-09-28 17:01:02 +0000935- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000936 after interpretation of symbolic links. On non-Unix systems, this
937 is an alias for os.path.abspath().
938
Tim Peters16a77ad2001-09-08 04:00:12 +0000939- operator.indexOf() (PySequence_Index() in the C API) now works with any
940 iterable object.
941
Guido van Rossum624c8af2001-09-18 15:21:04 +0000942- smtplib now supports various authentication and security features of
943 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000944
Guido van Rossum624c8af2001-09-18 15:21:04 +0000945- hmac: a new module implementing keyed hashing for message
946 authentication.
947
948- mimetypes now recognizes more extensions and file types. At the
949 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000950
Guido van Rossum624c8af2001-09-18 15:21:04 +0000951- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000952 Python 2.2 bytecode generation. It has also been promoted from a
953 Tool to a standard library package. (Tools/compiler still exists as
954 a sample driver.)
955
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000956Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000957
Tim Petersb07352e2001-09-08 01:25:47 +0000958Build
959
Guido van Rossum624c8af2001-09-18 15:21:04 +0000960- Large file support (LFS) is now automatic when the platform supports
961 it; no more manual configuration tweaks are needed. On Linux, at
962 least, it's possible to have a system whose C library supports large
963 files but whose kernel doesn't; in this case, large file support is
964 still enabled but doesn't do you any good unless you upgrade your
965 kernel or share your Python executable with another system whose
966 kernel has large file support.
967
968- The configure script now supplies plausible defaults in a
969 cross-compilation environment. This doesn't mean that the supplied
970 values are always correct, or that cross-compilation now works
971 flawlessly -- but it's a first step (and it shuts up most of
972 autoconf's warnings about AC_TRY_RUN).
973
974- The Unix build is now a bit less chatty, courtesy of the parser
975 generator. The build is completely silent (except for errors) when
976 using "make -s", thanks to a -q option to setup.py.
977
Tim Petersb07352e2001-09-08 01:25:47 +0000978C API
979
Guido van Rossum624c8af2001-09-18 15:21:04 +0000980- The "structmember" API now supports some new flag bits to deny read
981 and/or write access to attributes in restricted execution mode.
982
Tim Petersb07352e2001-09-08 01:25:47 +0000983New platforms
984
Guido van Rossum624c8af2001-09-18 15:21:04 +0000985- Compaq's iPAQ handheld, running the "familiar" Linux distribution
986 (http://familiar.handhelds.org).
987
Tim Petersb07352e2001-09-08 01:25:47 +0000988Tests
989
Tim Peters8a9c2842001-09-22 21:30:22 +0000990- The "classic" standard tests, which work by comparing stdout to
991 an expected-output file under Lib/test/output/, no longer stop at
992 the first mismatch. Instead the test is run to completion, and a
993 variant of ndiff-style comparison is used to report all differences.
994 This is much easier to understand than the previous style of reporting.
995
996- The unittest-based standard tests now use regrtest's test_main()
997 convention, instead of running as a side-effect of merely being
998 imported. This allows these tests to be run in more natural and
999 flexible ways as unittests, outside the regrtest framework.
1000
1001- regrtest.py is much better integrated with unittest and doctest now,
1002 especially in regard to reporting errors.
1003
Tim Petersb07352e2001-09-08 01:25:47 +00001004Windows
1005
Guido van Rossum624c8af2001-09-18 15:21:04 +00001006- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001007 that support it (NTFS under Windows 2000). See "What's New in
1008 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001009
Tim Petersb07352e2001-09-08 01:25:47 +00001010
Tim Petersedc99312001-08-22 21:36:50 +00001011What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001012Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001013===========================
1014
1015Core
1016
Tim Peters9fffa3e2001-09-04 05:14:19 +00001017- Conversion of long to float now raises OverflowError if the long is too
1018 big to represent as a C double.
1019
Tim Peters32f453e2001-09-03 08:35:41 +00001020- The 3-argument builtin pow() no longer allows a third non-None argument
1021 if either of the first two arguments is a float, or if both are of
1022 integer types and the second argument is negative (in which latter case
1023 the arguments are converted to float, so this is really the same
1024 restriction).
1025
Tim Peters5d2b77c2001-09-03 05:47:38 +00001026- The builtin dir() now returns more information, and sometimes much
1027 more, generally naming all attributes of an object, and all attributes
1028 reachable from the object via its class, and from its class's base
1029 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1030 an empty list. In 2.2a3,
1031
1032 >>> dir([])
1033 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1034 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1035 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1036 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1037 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1038 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1039 'reverse', 'sort']
1040
1041 dir(module) continues to return only the module's attributes, though.
1042
Tim Petersbdee63f2001-09-02 03:40:59 +00001043- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001044 than raising OverflowError. This is a partial implementation of PEP
1045 237. You can use -Wdefault::OverflowWarning to enable a warning for
1046 this situation, and -Werror::OverflowWarning to revert to the old
1047 OverflowError exception.
1048
Guido van Rossum61c345f2001-09-04 03:26:15 +00001049- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001050 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001051 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1052 -Qold, meaning the / operator has its classic meaning and no
1053 warnings are issued. Using -Qwarn issues a run-time warning about
1054 all uses of classic division for int and long arguments; -Qwarnall
1055 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001056 (for use with fixdiv.py).
1057 [Note: the remainder of this paragraph (preserved below) became
1058 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1059 <obsolete>
1060 Using -Qnew is questionable; it turns on new division by default, but
1061 only in the __main__ module. You can usefully combine -Qwarn or
1062 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1063 warns about classic division everywhere else.
1064 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001065
Tim Petersbdee63f2001-09-02 03:40:59 +00001066- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001067 long, float, str, unicode, and tuple. (The types complex, list and
1068 dictionary can also be subclassed; this was introduced earlier.)
1069 Note that restrictions apply when subclassing immutable built-in
1070 types: you can only affect the value of the instance by overloading
1071 __new__. You can add mutable attributes, and the subclass instances
1072 will have a __dict__ attribute, but you cannot change the "value"
1073 (as implemented by the base class) of an immutable subclass instance
1074 once it is created.
1075
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001076- The dictionary constructor now takes an optional argument, a
1077 mapping-like object, and initializes the dictionary from its
1078 (key, value) pairs.
1079
Tim Petersbdee63f2001-09-02 03:40:59 +00001080- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001081 "cooperative super calls" in a multiple inheritance setting. For an
1082 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1083
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001084- A new built-in type, property, has been added. This enables the
1085 creation of "properties". These are attributes implemented by
1086 getter and setter functions (or only one of these for read-only or
1087 write-only attributes), without the need to override __getattr__.
1088 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001089
Tim Petersbdee63f2001-09-02 03:40:59 +00001090- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001091 liberalized, to allow leading zeroes. Examples of literals now
1092 legal that were SyntaxErrors before:
1093
1094 00.0 0e3 0100j 07.5 00000000000000000008.
1095
Tim Petersbdee63f2001-09-02 03:40:59 +00001096- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001097 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1098
Tim Petersedc99312001-08-22 21:36:50 +00001099Library
1100
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001101- telnetlib includes symbolic names for the options, and support for
1102 setting an option negotiation callback.
1103
Tim Petersa40c7932001-09-05 22:36:56 +00001104- The new C standard no longer requires that math libraries set errno to
1105 ERANGE on overflow. For platform libraries that exploit this new
1106 freedom, Python's overflow-checking was wholly broken. A new overflow-
1107 checking scheme attempts to repair that, but may not be reliable on all
1108 platforms (C doesn't seem to provide anything both useful and portable
1109 in this area anymore).
1110
Martin v. Löwis44f86962001-09-05 13:44:54 +00001111- Asynchronous timeout actions are available through the new class
1112 threading.Timer.
1113
Tim Peters78526162001-09-05 00:53:45 +00001114- math.log and math.log10 now return sensible results for even huge
1115 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1116
Tim Petersbdee63f2001-09-02 03:40:59 +00001117- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001118 currently held. See the docs for the imp module.
1119
Tim Petersbdee63f2001-09-02 03:40:59 +00001120- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001121 dumps containing ints written on platforms where Python ints are 8 bytes.
1122 When read on a box where Python ints are 4 bytes, such values are
1123 converted to Python longs.
1124
Tim Petersbdee63f2001-09-02 03:40:59 +00001125- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001126 code objects is no longer allowed. This plugs a security hole.
1127
Steve Purcell6091cd62001-09-06 16:05:17 +00001128- unittest.TestResult instances no longer store references to tracebacks
1129 generated by test failures. This prevents unexpected dangling references
1130 to objects that should be garbage collected between tests.
1131
Tim Petersedc99312001-08-22 21:36:50 +00001132Tools
1133
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001134- Tools/scripts/fixdiv.py has been added which can be used to fix
1135 division operators as per PEP 238.
1136
Tim Petersedc99312001-08-22 21:36:50 +00001137Build
1138
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001139- If you are an adventurous person using Mac OS X you may want to look at
1140 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1141 application, which can be used for experimenting with Carbon or Cocoa.
1142 Discussion of this on pythonmac-sig, please.
1143
Tim Peters7eea37e2001-09-04 22:08:56 +00001144C API
1145
1146- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001147
Tim Peters9fffa3e2001-09-04 05:14:19 +00001148- Note that PyLong_AsDouble can fail! This has always been true, but no
1149 callers checked for it. It's more likely to fail now, because overflow
1150 errors are properly detected now. The proper way to check:
1151
1152 double x = PyLong_AsDouble(some_long_object);
1153 if (x == -1.0 && PyErr_Occurred()) {
1154 /* The conversion failed. */
1155 }
1156
Tim Petersbdee63f2001-09-02 03:40:59 +00001157- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001158 compile but will not participate in GC. To upgrade an extension
1159 module:
1160
1161 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001162
Neil Schemenauer4042c692001-08-30 15:38:01 +00001163 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1164 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001165
Neil Schemenauer4042c692001-08-30 15:38:01 +00001166 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1167 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001168
Neil Schemenauer4042c692001-08-30 15:38:01 +00001169 - remove PyGC_HEAD_SIZE from object size calculations
1170
1171 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1172
Tim Petersbdee63f2001-09-02 03:40:59 +00001173- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001174 These can be used safely to construct string objects from a
1175 sprintf-style format string (similar to the format string supported
1176 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001177
Tim Petersedc99312001-08-22 21:36:50 +00001178New platforms
1179
Tim Petersb7da0902001-09-02 23:01:43 +00001180- Stephen Hansen contributed patches sufficient to get a clean compile
1181 under Borland C (Windows), but he reports problems running it and ran
1182 out of time to complete the port. Volunteers? Expect a MemoryError
1183 when importing the types module; this is probably shallow, and
1184 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001185
Tim Petersedc99312001-08-22 21:36:50 +00001186Tests
1187
1188Windows
1189
Tim Peters6e13a562001-09-06 00:32:15 +00001190- Large file support is now enabled on Win32 platforms as well as on
1191 Win64. This means that, for example, you can use f.tell() and f.seek()
1192 to manipulate files larger than 2 gigabytes (provided you have enough
1193 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001194 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1195 filesize limit, and large file support makes no difference there.
1196 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1197 NTFS has no practical limit on file size, and files of any size can be
1198 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001199
Tim Petersbdee63f2001-09-02 03:40:59 +00001200- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001201 points to command.com (patch from Brian Quinlan).
1202
Tim Petersedc99312001-08-22 21:36:50 +00001203
Tim Peters20f51a72001-07-21 02:31:40 +00001204What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001205Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001206===========================
1207
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001208Build
1209
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001210- Tim Peters developed a brand new Windows installer using Wise 8.1,
1211 generously donated to us by Wise Solutions.
1212
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001213- configure supports a new option --enable-unicode, with the values
1214 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1215 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001216
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001217- A new configure option --enable-framework builds a Mac OS X framework,
1218 which "make frameworkinstall" will install. This provides a starting
1219 point for more mac-like functionality, join pythonmac-sig@python.org
1220 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001221
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001222- The NeXT platform is no longer supported.
1223
1224- The `new' module is now statically linked.
1225
Tim Peters0afb6092001-08-15 06:06:44 +00001226Tools
1227
1228- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001229 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001230 the module docstring for details.
1231
Tim Peters20f51a72001-07-21 02:31:40 +00001232Tests
1233
Tim Peters5e824c32001-08-12 22:25:01 +00001234- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001235 platforms, allowing to give clearer test result output. regrtest
1236 also has optional --use/-u switch to run normally disabled tests
1237 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001238
Tim Peters20f51a72001-07-21 02:31:40 +00001239- Several new tests in the standard test suite, with special thanks to
1240 Nick Mathewson.
1241
1242Core
1243
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001244- The floor division operator // has been added as outlined in PEP
1245 238. The / operator still provides classic division (and will until
1246 Python 3.0) unless "from __future__ import division" is included, in
1247 which case the / operator will provide true division. The operator
1248 module provides truediv() and floordiv() functions. Augmented
1249 assignment variants are included, as are the equivalent overloadable
1250 methods and C API methods. See the PEP for a full discussion:
1251 <http://python.sf.net/peps/pep-0238.html>
1252
Tim Peters6cd6a822001-08-17 22:11:27 +00001253- Future statements are now effective in simulated interactive shells
1254 (like IDLE). This should "just work" by magic, but read Michael
1255 Hudson's "Future statements in simulated shells" PEP 264 for full
1256 details: <http://python.sf.net/peps/pep-0264.html>.
1257
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001258- The type/class unification (PEP 252-253) was integrated into the
1259 trunk and is not so tentative any more (the exact specification of
1260 some features is still tentative). A lot of work has done on fixing
1261 bugs and adding robustness and features (performance still has to
1262 come a long way).
1263
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001264- Warnings about a mismatch in the Python API during extension import
1265 now use the Python warning framework (which makes it possible to
1266 write filters for these warnings).
1267
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001268- A function's __dict__ (aka func_dict) will now always be a
1269 dictionary. It used to be possible to delete it or set it to None,
1270 but now both actions raise TypeErrors. It is still legal to set it
1271 to a dictionary object. Getting func.__dict__ before any attributes
1272 have been assigned now returns an empty dictionary instead of None.
1273
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001274- A new command line option, -E, was added which disables the use of
1275 all environment variables, or at least those that are specifically
1276 significant to Python. Usually those have a name starting with
1277 "PYTHON". This was used to fix a problem where the tests fail if
1278 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1279 older distribution.
1280
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001281Library
1282
Tim Peters5e824c32001-08-12 22:25:01 +00001283- New class Differ and new functions ndiff() and restore() in difflib.py.
1284 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001285 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001286
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001287- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1288 value using the minimal quoting required for the value; more
1289 reliable than using xml.sax.saxutils.escape() for attribute values.
1290
1291- Readline completion support for cmd.Cmd was added.
1292
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001293- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1294
1295- Added function threading.BoundedSemaphore()
1296
1297- Added Ka-Ping Yee's cgitb.py module.
1298
1299- The `new' module now exposes the CO_xxx flags.
1300
Martin v. Löwis560da622001-11-24 09:24:51 +00001301- The gc module offers the get_referents function.
1302
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001303New platforms
1304
1305C API
1306
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001307- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1308 which provide a cross-platform implementations for the
1309 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1310 the standard sprintf() and vsprintf() C lib APIs, these versions
1311 apply bounds checking on the used buffer which enhances protection
1312 against buffer overruns.
1313
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001314- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001315 and extensions using different Unicode widths is rendered next to
1316 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001317 will result in an ImportError. Unicode extensions writers must make
1318 sure to check the Unicode width compatibility in their extensions by
1319 using at least one of the mangled Unicode APIs in the extension.
1320
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001321- Two new flags METH_NOARGS and METH_O are available in method definition
1322 tables to simplify implementation of methods with no arguments and a
1323 single untyped argument. Calling such methods is more efficient than
1324 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1325 deprecated.
1326
Tim Petersc1731372001-08-04 08:12:36 +00001327Windows
1328
1329- "import module" now compiles module.pyw if it exists and nothing else
1330 relevant is found.
1331
Tim Peters20f51a72001-07-21 02:31:40 +00001332
Guido van Rossum55a78992001-07-17 17:22:32 +00001333What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001334Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001335===========================
1336
1337Core
Tim Petersa814db52001-05-14 07:05:58 +00001338
Tim Peters6d6c1a32001-08-02 04:15:00 +00001339- TENTATIVELY, a large amount of code implementing much of what's
1340 described in PEP 252 (Making Types Look More Like Classes) and PEP
1341 253 (Subtyping Built-in Types) was added. This will be released
1342 with Python 2.2a1. Documentation will be provided separately
1343 through http://www.python.org/2.2/. The purpose of releasing this
1344 with Python 2.2a1 is to test backwards compatibility. It is
1345 possible, though not likely, that a decision is made not to release
1346 this code as part of 2.2 final, if any serious backwards
1347 incompapatibilities are found during alpha testing that cannot be
1348 repaired.
1349
Guido van Rossum55a78992001-07-17 17:22:32 +00001350- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001351 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001352 more 'yield' statements. See PEP 255. Since this adds a new
1353 keyword to the language, this feature must be enabled by including a
1354 future statement: "from __future__ import generators" (see PEP 236).
1355 Generators will become a standard feature in a future release
1356 (probably 2.3). Without this future statement, 'yield' remains an
1357 ordinary identifier, but a warning is issued each time it is used.
1358 (These warnings currently don't conform to the warnings framework of
1359 PEP 230; we intend to fix this in 2.2a2.)
1360
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001361- The UTF-16 codec was modified to be more RFC compliant. It will now
1362 only remove BOM characters at the start of the string and then
1363 only if running in native mode (UTF-16-LE and -BE won't remove a
1364 leading BMO character).
1365
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001366- Strings now have a new method .decode() to complement the already
1367 existing .encode() method. These two methods provide direct access
1368 to the corresponding decoders and encoders of the registered codecs.
1369
1370 To enhance the usability of the .encode() method, the special
1371 casing of Unicode object return values was dropped (Unicode objects
1372 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001373
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001374 Both methods will now return whatever the codec in charge of the
1375 requested encoding returns as object, e.g. Unicode codecs will
1376 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1377 will return u"äöü"). This enables codec writer to create codecs
1378 for various simple to use conversions.
1379
1380 New codecs were added to demonstrate these new features (the .encode()
1381 and .decode() columns indicate the type of the returned objects):
1382
1383 Name | .encode() | .decode() | Description
1384 ----------------------------------------------------------------------
1385 uu | string | string | UU codec (e.g. for email)
1386 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001387 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001388 zlib | string | string | zlib compression
1389 hex | string | string | 2-byte hex codec
1390 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1391
Mark Hammond2a0af792001-05-14 03:09:36 +00001392- Some operating systems now support the concept of a default Unicode
1393 encoding for file system operations. Notably, Windows supports 'mbcs'
1394 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001395 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001396 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001397
1398 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001399 functions that return filenames (such as os.listdir()) to return Python
1400 string objects pre-encoded using the default file system encoding for
1401 the platform. As this encoding is likely to be different from Python's
1402 default encoding, converting this name to a Unicode object before passing
1403 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001404 would attempt to use its default encoding (generally ASCII) rather than
1405 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001406
Tim Petersa814db52001-05-14 07:05:58 +00001407 In general, this change simply removes surprises when working with
1408 Unicode and the file system, making these operations work as you expect,
1409 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001410 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001411
Tim Peters61dff2b2001-05-08 15:43:37 +00001412- Float (and complex) literals in source code were evaluated to full
1413 precision only when running from a .py file; the same code loaded from a
1414 .pyc (or .pyo) file could suffer numeric differences starting at about the
1415 12th significant decimal digit. For example, on a machine with IEEE-754
1416 floating arithmetic,
1417
1418 x = 9007199254740992.0
1419 print long(x)
1420
1421 printed 9007199254740992 if run directly from .py, but 9007199254740000
1422 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1423 str(float) instead of repr(float) when building code objects. marshal
1424 now uses repr(float) instead, which should reproduce floats to full
1425 machine precision (assuming the platform C float<->string I/O conversion
1426 functions are of good quality).
1427
1428 This may cause floating-point results to change in some cases, and
1429 usually for the better, but may also cause numerically unstable
1430 algorithms to break.
1431
Tim Peters2f228e72001-05-13 00:19:31 +00001432- The implementation of dicts suffers fewer collisions, which has speed
1433 benefits. However, the order in which dict entries appear in dict.keys(),
1434 dict.values() and dict.items() may differ from previous releases for a
1435 given dict. Nothing is defined about this order, so no program should
1436 rely on it. Nevertheless, it's easy to write test cases that rely on the
1437 order by accident, typically because of printing the str() or repr() of a
1438 dict to an "expected results" file. See Lib/test/test_support.py's new
1439 sortdict(dict) function for a simple way to display a dict in sorted
1440 order.
1441
Tim Peters7a3bfc32001-06-12 01:22:22 +00001442- Many other small changes to dicts were made, resulting in faster
1443 operation along the most common code paths.
1444
Guido van Rossum10315822001-05-01 20:54:30 +00001445- Dictionary objects now support the "in" operator: "x in dict" means
1446 the same as dict.has_key(x).
1447
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001448- The update() method of dictionaries now accepts generic mapping
1449 objects. Specifically the argument object must support the .keys()
1450 and __getitem__() methods. This allows you to say, for example,
1451 {}.update(UserDict())
1452
Guido van Rossum10315822001-05-01 20:54:30 +00001453- Iterators were added; this is a generalized way of providing values
1454 to a for loop. See PEP 234. There's a new built-in function iter()
1455 to return an iterator. There's a new protocol to get the next value
1456 from an iterator using the next() method (in Python) or the
1457 tp_iternext slot (in C). There's a new protocol to get iterators
1458 using the __iter__() method (in Python) or the tp_iter slot (in C).
1459 Iterating (i.e. a for loop) over a dictionary generates its keys.
1460 Iterating over a file generates its lines.
1461
Tim Petersf553f892001-05-01 20:45:31 +00001462- The following functions were generalized to work nicely with iterator
1463 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001464 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001465 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1466 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001467 join() method of strings
1468 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001469 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1470 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001471 right-hand side of assignment statements with multiple targets, such as
1472 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001473
Tim Petersd85e1022001-05-11 21:51:48 +00001474- Accessing module attributes is significantly faster (for example,
1475 random.random or os.path or yourPythonModule.yourAttribute).
1476
Tim Peterse63415e2001-05-08 04:38:29 +00001477- Comparing dictionary objects via == and != is faster, and now works even
1478 if the keys and values don't support comparisons other than ==.
1479
Tim Peters95bf9392001-05-10 08:32:44 +00001480- Comparing dictionaries in ways other than == and != is slower: there were
1481 insecurities in the dict comparison implementation that could cause Python
1482 to crash if the element comparison routines for the dict keys and/or
1483 values mutated the dicts. Making the code bulletproof slowed it down.
1484
Tim Peterseb28ef22001-06-02 05:27:19 +00001485- Collisions in dicts are resolved via a new approach, which can help
1486 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001487 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001488 faster now. Thanks to Christian Tismer for pointing out the cause and
1489 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001490
Tim Peters52e155e2001-06-16 05:42:57 +00001491- repr() is much faster for large containers (dict, list, tuple).
1492
1493
Tim Petersa814db52001-05-14 07:05:58 +00001494Library
1495
Fred Drake960fdf92001-07-20 18:38:26 +00001496- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1497 were added to the string module. These a locale-indenpendent
1498 constants, unlike letters, lowercase, and uppercase. These are now
1499 use in appropriate locations in the standard library.
1500
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001501- The flags used in dlopen calls can now be configured using
1502 sys.setdlopenflags and queried using sys.getdlopenflags.
1503
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001504- Fredrik Lundh's xmlrpclib is now a standard library module. This
1505 provides full client-side XML-RPC support. In addition,
1506 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1507 one asyncore-based). Thanks to Eric Raymond for the documentation.
1508
Guido van Rossum643d3912001-07-05 14:46:25 +00001509- The xrange() object is simplified: it no longer supports slicing,
1510 repetition, comparisons, efficient 'in' checking, the tolist()
1511 method, or the start, stop and step attributes. See PEP 260.
1512
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001513- A new function fnmatch.filter to filter lists of file names was added.
1514
Barry Warsawffd674d2001-05-22 16:00:10 +00001515- calendar.py uses month and day names based on the current locale.
1516
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001517- strop is now *really* obsolete (this was announced before with 1.6),
1518 and issues DeprecationWarning when used (except for the four items
1519 that are still imported into string.py).
1520
Tim Petersa814db52001-05-14 07:05:58 +00001521- Cookie.py now sorts key+value pairs by key in output strings.
1522
1523- pprint.isrecursive(object) didn't correctly identify recursive objects.
1524 Now it does.
1525
Tim Peters95b3f782001-05-14 18:39:41 +00001526- pprint functions now much faster for large containers (tuple, list, dict).
1527
Tim Peters7b9542a2001-06-10 23:40:19 +00001528- New 'q' and 'Q' format codes in the struct module, corresponding to C
1529 types "long long" and "unsigned long long" (on Windows, __int64). In
1530 native mode, these can be used only when the platform C compiler supports
1531 these types (when HAVE_LONG_LONG is #define'd by the Python config
1532 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001533 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1534 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001535
Guido van Rossum83213cc2001-06-12 16:48:52 +00001536- The site module installs a new built-in function 'help' that invokes
1537 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1538 it displays a message reminding the user to use 'help()' or
1539 'help(object)'.
1540
Tim Petersa814db52001-05-14 07:05:58 +00001541Tests
1542
1543- New test_mutants.py runs dict comparisons where the key and value
1544 comparison operators mutute the dicts randomly during comparison. This
1545 rapidly causes Python to crash under earlier releases (not for the faint
1546 of heart: it can also cause Win9x to freeze or reboot!).
1547
1548- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001549 pprint.isreadable() return sensible results. Also verifies that simple
1550 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001551
Tim Peters4324aa32001-05-28 22:30:08 +00001552C API
1553
1554- Removed the unused last_is_sticky argument from the internal
1555 _PyTuple_Resize(). If this affects you, you were cheating.
1556
1557
Guido van Rossum55a78992001-07-17 17:22:32 +00001558======================================================================
1559
1560
Guido van Rossumffe13be2001-04-16 18:46:45 +00001561What's New in Python 2.1 (final)?
1562=================================
1563
1564We only changed a few things since the last release candidate, all in
1565Python library code:
1566
1567- A bug in the locale module was fixed that affected locales which
1568 define no grouping for numeric formatting.
1569
1570- A few bugs in the weakref module's implementations of weak
1571 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1572 and the test suite was updated to check for these bugs.
1573
1574- An old bug in the os.path.walk() function (introduced in Python
1575 2.0!) was fixed: a non-existent file would cause an exception
1576 instead of being ignored.
1577
1578- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1579 PyChecker.
1580
1581
Guido van Rossum5b08f132001-04-16 02:05:23 +00001582What's New in Python 2.1c2?
1583===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001584
Guido van Rossum5b08f132001-04-16 02:05:23 +00001585A flurry of small changes, and one showstopper fixed in the nick of
1586time made it necessary to release another release candidate. The list
1587here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001588
Guido van Rossum5b08f132001-04-16 02:05:23 +00001589Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001590
Guido van Rossum5b08f132001-04-16 02:05:23 +00001591- Tim discovered a nasty bug in the dictionary code, caused by
1592 PyDict_Next() calling dict_resize(), and the GC code's use of
1593 PyDict_Next() violating an assumption in dict_items(). This was
1594 fixed with considerable amounts of band-aid, but the net effect is a
1595 saner and more robust implementation.
1596
1597- Made a bunch of symbols static that were accidentally global.
1598
1599Build and Ports
1600
1601- The setup.py script didn't check for a new enough version of zlib
1602 (1.1.3 is needed). Now it does.
1603
1604- Changed "make clean" target to also remove shared libraries.
1605
1606- Added a more general warning about the SGI Irix optimizer to README.
1607
1608Library
1609
1610- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1611 omitted the slash between host and file.html.
1612
1613- The mailbox module's _Mailbox class contained a completely broken
1614 and undocumented seek() method. Ripped it out.
1615
1616- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1617 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1618
1619- Fixed a few last-minute bugs in unittest.
1620
1621Extensions
1622
1623- Reverted the patch to the OpenSSL code in socketmodule.c to support
1624 RAND_status() and the EGD, and the subsequent patch that tried to
1625 fix it for pre-0.9.5 versions; the problem with the patch is that on
1626 some systems it issues a warning whenever socket is imported, and
1627 that's unacceptable.
1628
1629Tests
1630
1631- Fixed the pickle tests to work with "import test.test_pickle".
1632
1633- Tweaked test_locale.py to actually run the test Windows.
1634
1635- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1636 not "wb" (which is not a valid mode at all).
1637
1638- Fix pstats browser crashes. Import readline if it exists to make
1639 the user interface nicer.
1640
1641- Add "import thread" to the top of test modules that import the
1642 threading module (test_asynchat and test_threadedtempfile). This
1643 prevents test failures caused by a broken threading module resulting
1644 from a previously caught failed import.
1645
1646- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1647 needed on some platforms (e.g. Solaris 8) when the tests are run
1648 twice in succession.
1649
1650- Skip rather than fail test_sunaudiodev if no audio device is found.
1651
1652
1653What's New in Python 2.1c1?
1654===========================
1655
1656This list was significantly updated when 2.1c2 was released; the 2.1c1
1657release didn't mention most changes that were actually part of 2.1c1:
1658
1659Legal
1660
1661- Copyright was assigned to the Python Software Foundation (PSF) and a
1662 PSF license (very similar to the CNRI license) was added.
1663
1664- The CNRI copyright notice was updated to include 2001.
1665
1666Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001667
Guido van Rossumc9932722001-04-12 02:31:27 +00001668- After a public outcry, assignment to __debug__ is no longer illegal;
1669 instead, a warning is issued. It will become illegal in 2.2.
1670
Guido van Rossum5b08f132001-04-16 02:05:23 +00001671- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1672 "%#x" now always prepends "0x", even if the value is zero.
1673
1674- Fixed some nits in the bytecode compiler.
1675
1676- Fixed core dumps when calling certain kinds of non-functions.
1677
1678- Fixed various core dumps caused by reference count bugs.
1679
1680Build and Ports
1681
1682- Use INSTALL_SCRIPT to install script files.
1683
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001684- New port: SCO Unixware 7, by Billy G. Allie.
1685
Guido van Rossum5b08f132001-04-16 02:05:23 +00001686- Updated RISCOS port.
1687
1688- Updated BeOS port and notes.
1689
1690- Various other porting problems resolved.
1691
1692Library
1693
1694- The TERMIOS and SOCKET modules are now truly obsolete and
1695 unnecessary. Their symbols are incorporated in the termios and
1696 socket modules.
1697
1698- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1699 better tests for pickling.
1700
1701- threading: make Condition.wait() robust against KeyboardInterrupt.
1702
1703- zipfile: add support to zipfile to support opening an archive
1704 represented by an open file rather than a file name. Fix bug where
1705 the archive was not properly closed. Fixed a bug in this bugfix
1706 where flush() was called for a read-only file.
1707
1708- imputil: added an uninstall() method to the ImportManager.
1709
1710- Canvas: fixed bugs in lower() and tkraise() methods.
1711
1712- SocketServer: API change (added overridable close_request() method)
1713 so that the TCP server can explicitly close the request.
1714
1715- pstats: Eric Raymond added a simple interactive statistics browser,
1716 invoked when the module is run as a script.
1717
1718- locale: fixed a problem in format().
1719
1720- webbrowser: made it work when the BROWSER environment variable has a
1721 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1722 KDE 2. Fixed some other nits.
1723
1724- unittest: changes to allow using a different exception than
1725 AssertionError, and added a few more function aliases. Some other
1726 small changes.
1727
1728- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1729
1730- asynchat: fixed a critical bug in asynchat that slipped through the
1731 2.1b2 release. Fixed another rare bug.
1732
1733- Fix some unqualified except: clauses (always a bad code example).
1734
1735XML
1736
1737- pyexpat: new API get_version_string().
1738
1739- Fixed some minidom bugs.
1740
1741Extensions
1742
1743- Fixed a core dump in _weakref. Removed the weakref.mapping()
1744 function (it adds nothing to the API).
1745
1746- Rationalized the use of header files in the readline module, to make
1747 it compile (albeit with some warnings) with the very recent readline
1748 4.2, without breaking for earlier versions.
1749
1750- Hopefully fixed a buffering problem in linuxaudiodev.
1751
1752- Attempted a fix to make the OpenSSL support in the socket module
1753 work again with pre-0.9.5 versions of OpenSSL.
1754
1755Tests
1756
1757- Added a test case for asynchat and asyncore.
1758
1759- Removed coupling between tests where one test failing could break
1760 another.
1761
1762Tools
1763
1764- Ping added an interactive help browser to pydoc, fixed some nits
1765 in the rest of the pydoc code, and added some features to his
1766 inspect module.
1767
1768- An updated python-mode.el version 4.1 which integrates Ken
1769 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1770 much nicer in XEmacs and Emacs. When stepping through your program
1771 with pdb, in either the shell window or the *Python* window, the
1772 source file and line will be tracked by an arrow. Very cool!
1773
1774- IDLE: syntax warnings in interactive mode are changed into errors.
1775
1776- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001777 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001778
1779- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001780
Barry Warsaw11e89c72001-04-11 20:37:57 +00001781
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001782What's New in Python 2.1 beta 2?
1783================================
1784
Guido van Rossum053ae352001-03-22 14:17:21 +00001785(Unlisted are many fixed bugs, more documentation, etc.)
1786
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001787Core language, builtins, and interpreter
1788
Guido van Rossum053ae352001-03-22 14:17:21 +00001789- The nested scopes work (enabled by "from __future__ import
1790 nested_scopes") is completed; in particular, the future now extends
1791 into code executed through exec, eval() and execfile(), and into the
1792 interactive interpreter.
1793
1794- When calling a base class method (e.g. BaseClass.__init__(self)),
1795 this is now allowed even if self is not strictly spoken a class
1796 instance (e.g. when using metaclasses or the Don Beaudry hook).
1797
1798- Slice objects are now comparable but not hashable; this prevents
1799 dict[:] from being accepted but meaningless.
1800
1801- Complex division is now calculated using less braindead algorithms.
1802 This doesn't change semantics except it's more likely to give useful
1803 results in extreme cases. Complex repr() now uses full precision
1804 like float repr().
1805
1806- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1807
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001808- It is illegal to assign to the name __debug__, which is set when the
1809 interpreter starts. It is effectively a compile-time constant.
1810
1811- A warning will be issued if a global statement for a variable
1812 follows a use or assignment of that variable.
1813
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001814Standard library
1815
Guido van Rossum053ae352001-03-22 14:17:21 +00001816- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1817 inspired by JUnit), is now part of the standard library. You now
1818 have a choice of two testing frameworks: unittest requires you to
1819 write testcases as separate code, doctest gathers them from
1820 docstrings. Both approaches have their advantages and
1821 disadvantages.
1822
1823- A new module Tix was added, which wraps the Tix extension library
1824 for Tk. With that module, it is not necessary to statically link
1825 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1826 require" command. See Demo/tix/.
1827
1828- tzparse.py is now obsolete.
1829
1830- In gzip.py, the seek() and tell() methods are removed -- they were
1831 non-functional anyway, and it's better if callers can test for their
1832 existence with hasattr().
1833
1834Python/C API
1835
1836- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1837 that's already in the dictionary during a PyDict_Next() iteration.
1838 This used to fail occasionally when a dictionary resize operation
1839 could be triggered that would rehash all the keys. All other
1840 modifications to the dictionary are still off-limits during a
1841 PyDict_Next() iteration!
1842
1843- New extended APIs related to passing compiler variables around.
1844
1845- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1846 implement isinstance() and issubclass().
1847
1848- Py_BuildValue() now has a "D" conversion to create a Python complex
1849 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001850
Fred Drake4e262a92001-03-22 18:26:47 +00001851- Extensions types which support weak references must now set the
1852 field allocated for the weak reference machinery to NULL themselves;
1853 this is done to avoid the cost of checking each object for having a
1854 weakly referencable type in PyObject_INIT(), since most types are
1855 not weakly referencable.
1856
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001857- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1858 free variables and cell variables to and from the frame's f_locals.
1859
1860- Variants of several functions defined in pythonrun.h have been added
1861 to support the nested_scopes future statement. The variants all end
1862 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1863 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1864 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001865 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001866
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001867Distutils
1868
1869- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1870 into the release tree.
1871
Tim Peters0e57abf2001-05-02 07:39:38 +00001872- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001873 (an uninstaller, more customization of the installer's display)
1874
1875- from Jack Jansen: added Mac-specific code to generate a dialog for
1876 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001877 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001878 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001879
1880- added 'platforms' and 'keywords' to the set of metadata that can be
1881 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001882
1883- applied patches from Jason Tishler to make the compiler class work with
1884 Cygwin.
1885
1886
Tim Peters2fe289a2001-03-01 22:19:38 +00001887What's New in Python 2.1 beta 1?
1888================================
Tim Petersd66595f2001-02-04 03:09:53 +00001889
1890Core language, builtins, and interpreter
1891
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001892- Following an outcry from the community about the amount of code
1893 broken by the nested scopes feature introduced in 2.1a2, we decided
1894 to make this feature optional, and to wait until Python 2.2 (or at
1895 least 6 months) to make it standard. The option can be enabled on a
1896 per-module basis by adding "from __future__ import nested_scopes" at
1897 the beginning of a module (before any other statements, but after
1898 comments and an optional docstring). See PEP 236 (Back to the
1899 __future__) for a description of the __future__ statement. PEP 227
1900 (Statically Nested Scopes) has been updated to reflect this change,
1901 and to clarify the semantics in a number of endcases.
1902
1903- The nested scopes code, when enabled, has been hardened, and most
1904 bugs and memory leaks in it have been fixed.
1905
1906- Compile-time warnings are now generated for a number of conditions
1907 that will break or change in meaning when nested scopes are enabled:
1908
1909 - Using "from...import *" or "exec" without in-clause in a function
1910 scope that also defines a lambda or nested function with one or
1911 more free (non-local) variables. The presence of the import* or
1912 bare exec makes it impossible for the compiler to determine the
1913 exact set of local variables in the outer scope, which makes it
1914 impossible to determine the bindings for free variables in the
1915 inner scope. To avoid the warning about import *, change it into
1916 an import of explicitly name object, or move the import* statement
1917 to the global scope; to avoid the warning about bare exec, use
1918 exec...in... (a good idea anyway -- there's a possibility that
1919 bare exec will be deprecated in the future).
1920
1921 - Use of a global variable in a nested scope with the same name as a
1922 local variable in a surrounding scope. This will change in
1923 meaning with nested scopes: the name in the inner scope will
1924 reference the variable in the outer scope rather than the global
1925 of the same name. To avoid the warning, either rename the outer
1926 variable, or use a global statement in the inner function.
1927
Neil Schemenauera35c6882001-02-27 04:45:05 +00001928- An optional object allocator has been included. This allocator is
1929 optimized for Python objects and should be faster and use less memory
1930 than the standard system allocator. It is not enabled by default
1931 because of possible thread safety problems. The allocator is only
1932 protected by the Python interpreter lock and it is possible that some
1933 extension modules require a thread safe allocator. The object
1934 allocator can be enabled by providing the "--with-pymalloc" option to
1935 configure.
1936
Tim Petersd66595f2001-02-04 03:09:53 +00001937Standard library
1938
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001939- pyexpat now detects the expat version if expat.h defines it. A
1940 number of additional handlers are provided, which are only available
1941 since expat 1.95. In addition, the methods SetParamEntityParsing and
1942 GetInputContext of Parser objects are available with 1.95.x
1943 only. Parser objects now provide the ordered_attributes and
1944 specified_attributes attributes. A new module expat.model was added,
1945 which offers a number of additional constants if 1.95.x is used.
1946
1947- xml.dom offers the new functions registerDOMImplementation and
1948 getDOMImplementation.
1949
1950- xml.dom.minidom offers a toprettyxml method. A number of DOM
1951 conformance issues have been resolved. In particular, Element now
1952 has an hasAttributes method, and the handling of namespaces was
1953 improved.
1954
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001955- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1956 getting information about live Python code, and pydoc.py, a module
1957 for interactively converting docstrings to HTML or text.
1958 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001959 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001960 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1961 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001962
Tim Peters1eff7962001-03-01 02:31:33 +00001963- New library module difflib.py, primarily packaging the SequenceMatcher
1964 class at the heart of the popular ndiff.py file-comparison tool.
1965
1966- doctest.py (a framework for verifying Python code examples in docstrings)
1967 is now part of the std library.
1968
Tim Petersd66595f2001-02-04 03:09:53 +00001969Windows changes
1970
Guido van Rossume3955a82001-03-02 14:05:59 +00001971- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1972 small GUI that lets you browse the module docstrings using your
1973 default web browser.
1974
Tim Peters1eff7962001-03-01 02:31:33 +00001975- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1976 Platforms) is implemented. See
1977
1978 http://python.sourceforge.net/peps/pep-0235.html
1979
1980 for full details, especially the "Current Lower-Left Semantics" section.
1981 The new Windows import rules are simpler than before:
1982
1983 A. If the PYTHONCASEOK environment variable exists, same as
1984 before: silently accept the first case-insensitive match of any
1985 kind; raise ImportError if none found.
1986
1987 B. Else search sys.path for the first case-sensitive match; raise
1988 ImportError if none found.
1989
1990 The same rules have been implented on other platforms with case-
1991 insensitive but case-preserving filesystems too (including Cygwin, and
1992 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001993
Tim Peters25a9ce32001-02-19 07:06:36 +00001994- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1995 what it's supposed to do (and does do under NT and 2000) via direct
1996 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001997 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001998 all Win9x systems before.
1999
Tim Peters1eff7962001-03-01 02:31:33 +00002000- Build: Subproject _test (effectively) renamed to _testcapi.
2001
Tim Peters2fe289a2001-03-01 22:19:38 +00002002New platforms
2003
2004- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2005 Thanks to Steven Majewski!
2006
2007- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2008 Tishler!
2009
Guido van Rossum9089b272001-03-02 06:49:50 +00002010- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2011 Schwertberger! See RISCOS/README for more information -- it seems
2012 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002013 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002014
Tim Peters25a9ce32001-02-19 07:06:36 +00002015
Tim Petersd7b5e882001-01-25 03:36:26 +00002016What's New in Python 2.1 alpha 2?
2017=================================
Tim Peters40ead762001-01-27 05:35:26 +00002018
Tim Petersd7b5e882001-01-25 03:36:26 +00002019Core language, builtins, and interpreter
2020
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002021- Scopes nest. If a name is used in a function or class, but is not
2022 local, the definition in the nearest enclosing function scope will
2023 be used. One consequence of this change is that lambda statements
2024 could reference variables in the namespaces where the lambda is
2025 defined. In some unusual cases, this change will break code.
2026
2027 In all previous version of Python, names were resolved in exactly
2028 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002029 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002030 function A is defined within a function B, the names bound in B are
2031 not visible in A. The new rules make names bound in B visible in A,
2032 unless A contains a name binding that hides the binding in B.
2033
2034 Section 4.1 of the reference manual describes the new scoping rules
2035 in detail. The test script in Lib/test/test_scope.py demonstrates
2036 some of the effects of the change.
2037
2038 The new rules will cause existing code to break if it defines nested
2039 functions where an outer function has local variables with the same
2040 name as globals or builtins used by the inner function. Example:
2041
2042 def munge(str):
2043 def helper(x):
2044 return str(x)
2045 if type(str) != type(''):
2046 str = helper(str)
2047 return str.strip()
2048
2049 Under the old rules, the name str in helper() is bound to the
2050 builtin function str(). Under the new rules, it will be bound to
2051 the argument named str and an error will occur when helper() is
2052 called.
2053
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002054- The compiler will report a SyntaxError if "from ... import *" occurs
2055 in a function or class scope. The language reference has documented
2056 that this case is illegal, but the compiler never checked for it.
2057 The recent introduction of nested scope makes the meaning of this
2058 form of name binding ambiguous. In a future release, the compiler
2059 may allow this form when there is no possibility of ambiguity.
2060
Tim Peters40ead762001-01-27 05:35:26 +00002061- repr(string) is easier to read, now using hex escapes instead of octal,
2062 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2063
2064 >>> "\texample \r\n" + chr(0) + chr(255)
2065 '\texample \r\n\x00\xff' # in 2.1
2066 '\011example \015\012\000\377' # in 2.0
2067
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002068- Functions are now compared and hashed by identity, not by value, since
2069 the func_code attribute is writable.
2070
Fred Drakefb9d7122001-02-01 20:00:40 +00002071- Weak references (PEP 205) have been added. This involves a few
2072 changes in the core, an extension module (_weakref), and a Python
2073 module (weakref). The weakref module is the public interface. It
2074 includes support for "explicit" weak references, proxy objects, and
2075 mappings with weakly held values.
2076
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002077- A 'continue' statement can now appear in a try block within the body
2078 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002079 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002080
Tim Petersd7b5e882001-01-25 03:36:26 +00002081Standard library
2082
Barry Warsaw30dbd142001-01-31 22:14:01 +00002083- mailbox.py now has a new class, PortableUnixMailbox which is
2084 identical to UnixMailbox but uses a more portable scheme for
2085 determining From_ separators. Also, the constructors for all the
2086 classes in this module have a new optional `factory' argument, which
2087 is a callable used when new message classes must be instantiated by
2088 the next() method.
2089
Tim Petersd7b5e882001-01-25 03:36:26 +00002090- random.py is now self-contained, and offers all the functionality of
2091 the now-deprecated whrandom.py. See the docs for details. random.py
2092 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002093 and restoring the internal state of the generator; and jumpahead(n),
2094 for quickly forcing the internal state to be the same as if n calls to
2095 random() had been made. The latter is particularly useful for multi-
2096 threaded programs, creating one instance of the random.Random() class for
2097 each thread, then using .jumpahead() to force each instance to use a
2098 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002099
Tim Peters0de88fc2001-02-01 04:59:18 +00002100- random.py's seed() function is new. For bit-for-bit compatibility with
2101 prior releases, use the whseed function instead. The new seed function
2102 addresses two problems: (1) The old function couldn't produce more than
2103 about 2**24 distinct internal states; the new one about 2**45 (the best
2104 that can be done in the Wichmann-Hill generator). (2) The old function
2105 sometimes produced identical internal states when passed distinct
2106 integers, and there was no simple way to predict when that would happen;
2107 the new one guarantees to produce distinct internal states for all
2108 arguments in [0, 27814431486576L).
2109
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002110- The socket module now supports raw packets on Linux. The socket
2111 family is AF_PACKET.
2112
Tim Peters9ea17ac2001-02-02 05:57:15 +00002113- test_capi.py is a start at running tests of the Python C API. The tests
2114 are implemented by the new Modules/_testmodule.c.
2115
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002116- A new extension module, _symtable, provides provisional access to the
2117 internal symbol table used by the Python compiler. A higher-level
2118 interface will be added on top of _symtable in a future release.
2119
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002120- Removed the obsolete soundex module.
2121
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002122- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2123 the isSameNode method; NamedNodeMap the get method.
2124
2125- xml.sax.expatreader supports the lexical handler property; it
2126 generates comment, startCDATA, and endCDATA events.
2127
Tim Petersee826f82001-01-31 19:39:44 +00002128Windows changes
2129
2130- Build procedure: the zlib project is built in a different way that
2131 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002132 the zlib binary used. See PCbuild\readme.txt for details. Your old
2133 zlib-related directories can be deleted; you'll need to download fresh
2134 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002135
Tim Peters9ea17ac2001-02-02 05:57:15 +00002136- Build: New subproject _test for the benefit of test_capi.py (see above).
2137
Tim Petersb16c56f2001-02-02 21:24:51 +00002138- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2139 interface to some Python compiler internals).
2140
2141- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002142 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002143
Tim Petersa3a3a032000-11-30 05:22:44 +00002144What's New in Python 2.1 alpha 1?
2145=================================
2146
2147Core language, builtins, and interpreter
2148
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002149- There is a new Unicode companion to the PyObject_Str() API
2150 called PyObject_Unicode(). It behaves in the same way as the
2151 former, but assures that the returned value is an Unicode object
2152 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002153
Guido van Rossumf98eda02001-01-17 15:54:45 +00002154- The comparison operators support "rich comparison overloading" (PEP
2155 207). C extension types can provide a rich comparison function in
2156 the new tp_richcompare slot in the type object. The cmp() function
2157 and the C function PyObject_Compare() first try the new rich
2158 comparison operators before trying the old 3-way comparison. There
2159 is also a new C API PyObject_RichCompare() (which also falls back on
2160 the old 3-way comparison, but does not constrain the outcome of the
2161 rich comparison to a Boolean result).
2162
2163 The rich comparison function takes two objects (at least one of
2164 which is guaranteed to have the type that provided the function) and
2165 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2166 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2167 object, which may be NotImplemented (in which case the tp_compare
2168 slot function is used as a fallback, if defined).
2169
2170 Classes can overload individual comparison operators by defining one
2171 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002172 __ge__. There are no explicit "reflected argument" versions of
2173 these; instead, __lt__ and __gt__ are each other's reflection,
2174 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2175 reflection (similar at the C level). No other implications are
2176 made; in particular, Python does not assume that == is the Boolean
2177 inverse of !=, or that < is the Boolean inverse of >=. This makes
2178 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002179
2180 Classes or types that want to implement (in)equality tests but not
2181 the ordering operators (i.e. unordered types) should implement ==
2182 and !=, and raise an error for the ordering operators.
2183
Guido van Rossuma88479f2001-01-18 14:28:08 +00002184 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002185 Boolean; e.g. a matrix type might want to return a matrix of bits
2186 for A < B, giving elementwise comparisons. Such types should ensure
2187 that any interpretation of their value in a Boolean context raises
2188 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2189 at the C level) to always raise an exception.
2190
Guido van Rossuma88479f2001-01-18 14:28:08 +00002191- Complex numbers use rich comparisons to define == and != but raise
2192 an exception for <, <=, > and >=. Unfortunately, this also means
2193 that cmp() of two complex numbers raises an exception when the two
2194 numbers differ. Since it is not mathematically meaningful to compare
2195 complex numbers except for equality, I hope that this doesn't break
2196 too much code.
2197
Tim Peters3389f192001-02-18 08:48:49 +00002198- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002199 not defined by the language, other than that it's arbitrary but
2200 consistent (see the Reference Manual). An implementation detail changed
2201 in 2.1a1 such that None now compares less than any other object. Code
2202 relying on this new behavior (like code that relied on the previous
2203 behavior) does so at its own risk.
2204
Barry Warsaw573b5412001-01-15 20:43:18 +00002205- Functions and methods now support getting and setting arbitrarily
2206 named attributes (PEP 232). Functions have a new __dict__
2207 (a.k.a. func_dict) which hold the function attributes. Methods get
2208 and set attributes on their underlying im_func. It is a TypeError
2209 to set an attribute on a bound method.
2210
Guido van Rossum051e3352001-01-15 19:11:10 +00002211- The xrange() object implementation has been improved so that
2212 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2213 limitation that in this case len(xrange(sys.maxint)) can't be
2214 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2215 work fine as long as the index i doesn't actually reach 2**31.
2216 (Python uses regular ints for sequence and string indices; fixing
2217 that is much more work.)
2218
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002219- Two changes to from...import:
2220
Guido van Rossumba381232001-02-03 15:06:40 +00002221 1) "from M import X" now works even if (after loading module M)
2222 sys.modules['M'] is not a real module; it's basically a getattr()
2223 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002224
2225 2) "from M import *" now looks for M.__all__ to decide which names to
2226 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2227 filters out names starting with '_' as before. Whether or not
2228 __all__ exists, there's no restriction on the type of M.
2229
Guido van Rossumf61f1662001-01-10 20:13:55 +00002230- File objects have a new method, xreadlines(). This is the fastest
2231 way to iterate over all lines in a file:
2232
2233 for line in file.xreadlines():
2234 ...do something to line...
2235
2236 See the xreadlines module (mentioned below) for how to do this for
2237 other file-like objects.
2238
2239- Even if you don't use file.xreadlines(), you may expect a speedup on
2240 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002241 quite a bit in platform-specific ways: on systems (like Linux) that
2242 support flockfile(), getc_unlocked(), and funlockfile(), those are
2243 used by default. On systems (like Windows) without getc_unlocked(),
2244 a complicated (but still thread-safe) method using fgets() is used by
2245 default.
2246
Tim Petersd52269b2001-01-25 06:23:18 +00002247 You can force use of the fgets() method by #define'ing
2248 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002249 getc_unlocked()).
2250
Tim Petersd52269b2001-01-25 06:23:18 +00002251 You can force fgets() not to be used by #define'ing
2252 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002253 test_bufio.py fails -- and let us know if it does!).
2254
2255- In addition, the fileinput module, while still slower than the other
2256 methods on most platforms, has been sped up too, by using
2257 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002258
2259- Support for run-time warnings has been added, including a new
2260 command line option (-W) to specify the disposition of warnings.
2261 See the description of the warnings module below.
2262
2263- Extensive changes have been made to the coercion code. This mostly
2264 affects extension modules (which can now implement mixed-type
2265 numerical operators without having to use coercion), but
2266 occasionally, in boundary cases the coercion semantics have changed
2267 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002268 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002269 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002270 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002271
Guido van Rossumf98eda02001-01-17 15:54:45 +00002272- In connection with the coercion changes, a new built-in singleton
2273 object, NotImplemented is defined. This can be returned for
2274 operations that wish to indicate they are not implemented for a
2275 particular combination of arguments. From C, this is
2276 Py_NotImplemented.
2277
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002278- The interpreter accepts now bytecode files on the command line even
2279 if they do not have a .pyc or .pyo extension. On Linux, after executing
2280
Martin v. Löwise214baa2001-02-04 22:37:56 +00002281import imp,sys,string
2282magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2283reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2284open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002285
2286 any byte code file can be used as an executable (i.e. as an argument
2287 to execve(2)).
2288
Tim Peters9940b802000-12-01 07:59:35 +00002289- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002290 character. In 1.6 and earlier, they never produced a sign,
2291 and raised an error if the value of the long was too large
2292 to fit in a Python int. In 2.0, they produced a sign if and
2293 only if too large to fit in an int. This was inconsistent
2294 across platforms (because the size of an int varies across
2295 platforms), and inconsistent with hex() and oct(). Example:
2296
2297 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002298 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002299 'ffffffbe' # in 2.0 and before, on 32-bit machines
2300 >>> hex(-0x42L)
2301 '-0x42L' # in all versions of Python
2302
Tim Peters9940b802000-12-01 07:59:35 +00002303 The behavior of %d formats for negative Python longs remains
2304 the same as in 2.0 (although in 1.6 and before, they raised
2305 an error if the long didn't fit in a Python int).
2306
2307 %u formats don't make sense for Python longs, but are allowed
2308 and treated the same as %d in 2.1. In 2.0, a negative long
2309 formatted via %u produced a sign if and only if too large to
2310 fit in an int. In 1.6 and earlier, a negative long formatted
2311 via %u raised an error if it was too big to fit in an int.
2312
Guido van Rossum3661d392000-12-12 22:10:31 +00002313- Dictionary objects have an odd new method, popitem(). This removes
2314 an arbitrary item from the dictionary and returns it (in the form of
2315 a (key, value) pair). This can be useful for algorithms that use a
2316 dictionary as a bag of "to do" items and repeatedly need to pick one
2317 item. Such algorithms normally end up running in quadratic time;
2318 using popitem() they can usually be made to run in linear time.
2319
Tim Peters36cdad12000-12-29 02:06:45 +00002320Standard library
2321
Thomas Woutersfe385252001-01-19 23:16:56 +00002322- In the time module, the time argument to the functions strftime,
2323 localtime, gmtime, asctime and ctime is now optional, defaulting to
2324 the current time (in the local timezone).
2325
Guido van Rossumda91f222001-01-15 16:36:08 +00002326- The ftplib module now defaults to passive mode, which is deemed a
2327 more useful default given that clients are often inside firewalls
2328 these days. Note that this could break if ftplib is used to connect
2329 to a *server* that is inside a firewall, from outside; this is
2330 expected to be a very rare situation. To fix that, you can call
2331 ftp.set_pasv(0).
2332
Martin v. Löwis10a27872001-01-13 09:54:41 +00002333- The module site now treats .pth files not only for path configuration,
2334 but also supports extensions to the initialization code: Lines starting
2335 with import are executed.
2336
Guido van Rossumf61f1662001-01-10 20:13:55 +00002337- There's a new module, warnings, which implements a mechanism for
2338 issuing and filtering warnings. There are some new built-in
2339 exceptions that serve as warning categories, and a new command line
2340 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2341 turns warnings into errors). warnings.warn(message[, category])
2342 issues a warning message; this can also be called from C as
2343 PyErr_Warn(category, message).
2344
2345- A new module xreadlines was added. This exports a single factory
2346 function, xreadlines(). The intention is that this code is the
2347 absolutely fastest way to iterate over all lines in an open
2348 file(-like) object:
2349
2350 import xreadlines
2351 for line in xreadlines.xreadlines(file):
2352 ...do something to line...
2353
2354 This is equivalent to the previous the speed record holder using
2355 file.readlines(sizehint). Note that if file is a real file object
2356 (as opposed to a file-like object), this is equivalent:
2357
2358 for line in file.xreadlines():
2359 ...do something to line...
2360
Tim Peters36cdad12000-12-29 02:06:45 +00002361- The bisect module has new functions bisect_left, insort_left,
2362 bisect_right and insort_right. The old names bisect and insort
2363 are now aliases for bisect_right and insort_right. XXX_right
2364 and XXX_left methods differ in what happens when the new element
2365 compares equal to one or more elements already in the list: the
2366 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002367 right. Code that doesn't care where equal elements end up should
2368 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002369
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002370- The new curses.panel module wraps the panel library that forms part
2371 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2372
Guido van Rossumf61f1662001-01-10 20:13:55 +00002373- The SocketServer module now sets the allow_reuse_address flag by
2374 default in the TCPServer class.
2375
2376- A new function, sys._getframe(), returns the stack frame pointer of
2377 the caller. This is intended only as a building block for
2378 higher-level mechanisms such as string interpolation.
2379
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002380- The pyexpat module supports a number of new handlers, which are
2381 available only in expat 1.2. If invocation of a callback fails, it
2382 will report an additional frame in the traceback. Parser objects
2383 participate now in garbage collection. If expat reports an unknown
2384 encoding, pyexpat will try to use a Python codec; that works only
2385 for single-byte charsets. The parser type objects is exposed as
2386 XMLParserObject.
2387
2388- xml.dom now offers standard definitions for symbolic node type and
2389 exception code constants, and a hierarchy of DOM exceptions. minidom
2390 was adjusted to use them.
2391
2392- The conformance of xml.dom.minidom to the DOM specification was
2393 improved. It detects a number of additional error cases; the
2394 previous/next relationship works even when the tree is modified;
2395 Node supports the normalize() method; NamedNodeMap, DocumentType and
2396 DOMImplementation classes were added; Element supports the
2397 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2398 method.
2399
Guido van Rossumf61f1662001-01-10 20:13:55 +00002400Build issues
2401
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002402- For Unix (and Unix-compatible) builds, configuration and building of
2403 extension modules is now greatly automated. Rather than having to
2404 edit the Modules/Setup file to indicate which modules should be
2405 built and where their include files and libraries are, a
2406 distutils-based setup.py script now takes care of building most
2407 extension modules. All extension modules built this way are built
2408 as shared libraries. Only a few modules that must be linked
2409 statically are still listed in the Setup file; you won't need to
2410 edit their configuration.
2411
2412- Python should now build out of the box on Cygwin. If it doesn't,
2413 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002414
2415- Python now always uses its own (renamed) implementation of getopt()
2416 -- there's too much variation among C library getopt()
2417 implementations.
2418
2419- C++ compilers are better supported; the CXX macro is always set to a
2420 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002421
Tim Petersd92dfe02000-12-12 01:18:41 +00002422Windows changes
2423
2424- select module: By default under Windows, a select() call
2425 can specify no more than 64 sockets. Python now boosts
2426 this Microsoft default to 512. If you need even more than
2427 that, see the MS docs (you'll need to #define FD_SETSIZE
2428 and recompile Python from source).
2429
Guido van Rossumf61f1662001-01-10 20:13:55 +00002430- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2431 subdirectory is no more!
2432
Tim Petersa3a3a032000-11-30 05:22:44 +00002433
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002434What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002435=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002436
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002437Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002438changes are in the file HISTORY. If you are making the jump directly
2439from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2440HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002441
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002442Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2443the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2444http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002445
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002446--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002447
2448======================================================================
2449
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002450What's new in 2.0 (since release candidate 1)?
2451==============================================
2452
2453Standard library
2454
2455- The copy_reg module was modified to clarify its intended use: to
2456 register pickle support for extension types, not for classes.
2457 pickle() will raise a TypeError if it is passed a class.
2458
2459- Fixed a bug in gettext's "normalize and expand" code that prevented
2460 it from finding an existing .mo file.
2461
2462- Restored support for HTTP/0.9 servers in httplib.
2463
Tim Peters989b7b92000-10-16 20:24:53 +00002464- The math module was changed to stop raising OverflowError in case of
2465 underflow, and return 0 instead in underflow cases. Whether Python
2466 used to raise OverflowError in case of underflow was platform-
2467 dependent (it did when the platform math library set errno to ERANGE
2468 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002469
2470- Fixed a bug in StringIO that occurred when the file position was not
2471 at the end of the file and write() was called with enough data to
2472 extend past the end of the file.
2473
2474- Fixed a bug that caused Tkinter error messages to get lost on
2475 Windows. The bug was fixed by replacing direct use of
2476 interp->result with Tcl_GetStringResult(interp).
2477
2478- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2479 redirect response.
2480
2481- Several changes were made to distutils: Some debugging code was
2482 removed from util. Fixed the installer used when an external zip
2483 program (like WinZip) is not found; the source code for this
2484 installer is in Misc/distutils. check_lib() was modified to behave
2485 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2486 test for whether installed modules are on sys.path was changed to
2487 use both normcase() and normpath().
2488
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002489- Several minor bugs were fixed in the xml package (the minidom,
2490 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002491
2492- The regression test driver (regrtest.py) behavior when invoked with
2493 -l changed: It now reports a count of objects that are recognized as
2494 garbage but not freed by the garbage collector.
2495
Tim Peters989b7b92000-10-16 20:24:53 +00002496- The regression test for the math module was changed to test
2497 exceptional behavior when the test is run in verbose mode. Python
2498 cannot yet guarantee consistent exception behavior across platforms,
2499 so the exception part of test_math is run only in verbose mode, and
2500 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002501
2502Internals
2503
2504- PyOS_CheckStack() has been disabled on Win64, where it caused
2505 test_sre to fail.
2506
2507Build issues
2508
2509- Changed compiler flags, so that gcc is always invoked with -Wall and
2510 -Wstrict-prototypes. Users compiling Python with GCC should see
2511 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002512 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002513 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002514
Tim Petersa3a3a032000-11-30 05:22:44 +00002515- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002516
2517Tools and other miscellany
2518
2519- The compiler in Tools/compiler was updated to support the new
2520 language features introduced in 2.0: extended print statement, list
2521 comprehensions, and augmented assignments. The new compiler should
2522 also be backwards compatible with Python 1.5.2; the compiler will
2523 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002524 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002525
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002526What's new in 2.0 release candidate 1 (since beta 2)?
2527=====================================================
2528
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002529What is release candidate 1?
2530
2531We believe that release candidate 1 will fix all known bugs that we
2532intend to fix for the 2.0 final release. This release should be a bit
2533more stable than the previous betas. We would like to see even more
2534widespread testing before the final release, so we are producing this
2535release candidate. The final release will be exactly the same unless
2536any show-stopping (or brown bag) bugs are found by testers of the
2537release candidate.
2538
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002539All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002540to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002541
2542Core language, builtins, and interpreter
2543
2544- A bug that caused crashes when __coerce__ was used with augmented
2545 assignment, e.g. +=, was fixed.
2546
2547- Raise ZeroDivisionError when raising zero to a negative number,
2548 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2549 power operator and the result of math.pow(0.0, -2.0) will vary by
2550 platform. On Linux, it raises a ValueError.
2551
2552- A bug in Unicode string interpolation was fixed that occasionally
2553 caused errors with formats including "%%". For example, the
2554 following expression "%% %s" % u"abc" no longer raises a TypeError.
2555
2556- Compilation of deeply nested expressions raises MemoryError instead
2557 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2558
2559- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2560 rendering them useless. They are now written in binary mode again.
2561
2562Standard library
2563
2564- Keyword arguments are now accepted for most pattern and match object
2565 methods in SRE, the standard regular expression engine.
2566
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002567- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002568 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002569
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002570- Several bugs in the Unicode handling and error handling in _tkinter
2571 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002572
2573- Fix memory management errors in Merge() and Tkapp_Call() routines.
2574
2575- Several changes were made to cStringIO to make it compatible with
2576 the file-like object interface and with StringIO. If operations are
2577 performed on a closed object, an exception is raised. The truncate
2578 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002579 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002580
2581- There were many changes made to the linuxaudiodev module and its
2582 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002583 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002584
2585 Note that this module is named poorly, because it should work
2586 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002587 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002588
2589 The module now raises exceptions when errors occur instead of
2590 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2591 audio) and defines a getptr() method that calls the
2592 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2593
2594- The library_version attribute, introduced in an earlier beta, was
2595 removed because it can not be supported with early versions of the C
2596 readline library, which provides no way to determine the version at
2597 compile-time.
2598
2599- The binascii module is now enabled on Win64.
2600
Tim Peters46446d62000-10-09 21:19:31 +00002601- tokenize.py no longer suffers "recursion depth" errors when parsing
2602 programs with very long string literals.
2603
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002604Internals
2605
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002606- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002607 which is called when the interpreter starts up to determine where
2608 the standard library is installed. These vulnerabilities affect all
2609 previous versions of Python and can be exploited by setting very
2610 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2611 setuid Python script, although use of the wrapper in
2612 Misc/setuid-prog.c will eliminate the vulnerability.
2613
2614- Fixed garbage collection bugs in instance creation that were
2615 triggered when errors occurred during initialization. The solution,
2616 applied in cPickle and in PyInstance_New(), is to call
2617 PyObject_GC_Init() after the initialization of the object's
2618 container attributes is complete.
2619
2620- pyexpat adds definitions of PyModule_AddStringConstant and
2621 PyModule_AddObject if the Python version is less than 2.0, which
2622 provides compatibility with PyXML on Python 1.5.2.
2623
2624- If the platform has a bogus definition for LONG_BIT (the number of
2625 bits in a long), an error will be reported at compile time.
2626
2627- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2628 collection crashes and possibly other, unreported crashes.
2629
2630- Fixed a memory leak in _PyUnicode_Fini().
2631
2632Build issues
2633
2634- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002635 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002636 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002637
2638- The mmap.PAGESIZE constant is now initialized using sysconf when
2639 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2640
2641- The md5 file should now compile on all platforms.
2642
2643- The select module now compiles on platforms that do not define
2644 POLLRDNORM and related constants.
2645
2646- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002647 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002648
Jeremy Hylton10921202000-10-09 18:34:12 +00002649- BeOS: A number of changes were made to the build and installation
2650 process. ar-fake now operates on a directory of object files.
2651 dl_export.h is gone, and its macros now appear on the mwcc command
2652 line during build on PPC BeOS.
2653
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002654- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002655 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002656
2657- Cygwin: Support for shared libraries, Tkinter, and sockets.
2658
2659- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2660
2661Tools and other miscellany
2662
2663- Removed debugging prints from main used with freeze.
2664
Tim Peters46446d62000-10-09 21:19:31 +00002665- IDLE auto-indent no longer crashes when it encounters Unicode
2666 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002667
2668What's new in 2.0 beta 2 (since beta 1)?
2669========================================
2670
2671Core language, builtins, and interpreter
2672
Tim Peters482c0212000-09-26 06:33:09 +00002673- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002674 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002675
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002676- Add -h and -V command line options to print the usage message and
2677 Python version number and exit immediately.
2678
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002679- eval() and exec accept Unicode objects as code parameters.
2680
2681- getattr() and setattr() now also accept Unicode objects for the
2682 attribute name, which are converted to strings using the default
2683 encoding before lookup.
2684
2685- Multiplication on string and Unicode now does proper bounds
2686 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2687 string is too long."
2688
2689- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002690 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002691
Jeremy Hylton1b618592000-09-26 05:32:36 +00002692
2693Standard library and extensions
2694
Guido van Rossum5b08f132001-04-16 02:05:23 +00002695- socket module: the OpenSSL code now adds support for RAND_status()
2696 and EGD (Entropy Gathering Device).
2697
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002698- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002699 argument checking; it still takes no arguments.
2700
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002701- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002703- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002704
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002705- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002706
2707- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002708 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002709
2710- copy: Copy Unicode objects atomically.
2711
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002712- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002713
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002714- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002715
Fred Drake67233bc2000-09-26 16:40:27 +00002716- dbm: Add get() and setdefault() methods to dbm object. Add constant
2717 `library' to module that names the library used. Added doc strings
2718 and method names to error messages. Uses configure to determine
2719 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2720 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002721
2722- distutils: Update to version 0.9.3.
2723
2724- dl: Add several dl.RTLD_ constants.
2725
2726- fpectl: Now supported on FreeBSD.
2727
2728- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2729 found by the collector will be saved in gc.garbage. This is useful
2730 for debugging a program that creates reference cycles.
2731
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002732- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002733 of HTTP class. Do not close socket on zero-length response. Do not
2734 crash when server sends invalid content-length header.
2735
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002736- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002737
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002738- marshal: When reading a short, sign-extend on platforms where shorts
2739 are bigger than 16 bits. When reading a long, repair the unportable
2740 sign extension that was being done for 64-bit machines. (It assumed
2741 that signed right shift sign-extends.)
2742
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002743- operator: Add contains(), invert(), __invert__() as aliases for
2744 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002745
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002746- os: Add support for popen2() and popen3() on all platforms where
2747 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002748
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002749- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002750 clicking on a file in Explorer (or passing the file name to the
2751 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002753- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002754 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002755
2756- pickle: Now raises ValueError when an invalid pickle that contains
2757 a non-string repr where a string repr was expected. This behavior
2758 matches cPickle.
2759
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002760- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002761
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002762- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002763
2764- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002765 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002766 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002767
2768- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002769 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002770
2771- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002772 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002773 few cycles during startup since the first call to
2774 setdefaultencoding() will initialize the codec registry and the
2775 encodings package.
2776
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002777- socket: Support for size hint in readlines() method of object returned
2778 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002780- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002781 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002782 is followed by whitespace.
2783
Tim Petersa3a3a032000-11-30 05:22:44 +00002784- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002785
2786- struct: Check ranges for bytes and shorts.
2787
2788- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002789 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002790
2791- Tkinter: Image objects are now guaranteed to have unique ids. Set
2792 event.delta to zero if Tk version doesn't support mousewheel.
2793 Removed some debugging prints.
2794
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002795- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002796
Fred Drake67233bc2000-09-26 16:40:27 +00002797- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798 which works around a bug in Norton AntiVirus 2000 that leads directly
2799 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002800
2801- xml: New version detection code allows PyXML to override standard
2802 XML package if PyXML version is greater than 0.6.1.
2803
Fred Drake64bb3802000-09-26 16:21:35 +00002804- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2805 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2806 tree only for nodes which are sufficiently interesting to a specific
2807 application. Does not provide the HTML-specific extensions. Still
2808 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002809
Fred Drake64bb3802000-09-26 16:21:35 +00002810- xml.sax: SAX 2 support for Python, including all the handler
2811 interfaces needed to process XML 1.0 compliant XML. Some
2812 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002813
Fred Drake64bb3802000-09-26 16:21:35 +00002814- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2815 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002816
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002817
Jeremy Hylton1b618592000-09-26 05:32:36 +00002818C API
2819
2820- Add three new convenience functions for module initialization --
2821 PyModule_AddObject(), PyModule_AddIntConstant(), and
2822 PyModule_AddStringConstant().
2823
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002824- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002825 removed and add #error to Python.h if NULL isn't defined after
2826 #include of stdio.h.
2827
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002828- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002829 backwards compatibility (at the source level) with old extensions.
2830
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002831- A wrapper API was added for signal() and sigaction(). Instead of
2832 either function, always use PyOS_getsig() to get a signal handler
2833 and PyOS_setsig() to set one. A new convenience typedef
2834 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002835
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002836- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002837 internal data buffer and size of a string object -- or the default
2838 encoded version of a Unicode object.
2839
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002840- PyString_Size() and PyString_AsString() accept Unicode objects.
2841
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002842- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002843 exists). INT_MAX and LONG_MAX will always be defined, even if
2844 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002845
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002846- PyFloat_FromString takes a second argument, pend, that was
2847 effectively useless. It is now officially useless but preserved for
2848 backwards compatibility. If the pend argument is not NULL, *pend is
2849 set to NULL.
2850
2851- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2852 for the attribute name. See note on getattr() above.
2853
2854- A few bug fixes to argument processing for Unicode.
2855 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2856 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2857 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002858 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002859
2860- Py_BuildValue accepts B format (for bgen-generated code).
2861
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002862
Jeremy Hylton1b618592000-09-26 05:32:36 +00002863Internals
2864
2865- On Unix, fix code for finding Python installation directory so that
2866 it works when argv[0] is a relative path.
2867
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002868- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002869 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002870 rather than by generating a copy of the object.
2871
Tim Peters482c0212000-09-26 06:33:09 +00002872- Several of the internal Unicode tables are much smaller now, and
2873 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002874
Jeremy Hylton97693b02000-09-26 17:42:51 +00002875- In the garbage collector: Fixed bug in collection of tuples. Fixed
2876 bug that caused some instances to be removed from the container set
2877 while they were still live. Fixed parsing in gc.set_debug() for
2878 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002879
2880- Fixed refcount problem in instance deallocation that only occurred
2881 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2882
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002883- On Windows, getpythonregpath is now protected against null data in
2884 registry key.
2885
2886- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002887 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002888
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002889
Jeremy Hylton1b618592000-09-26 05:32:36 +00002890Build and platform-specific issues
2891
2892- Better support of GNU Pth via --with-pth configure option.
2893
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002894- Python/C API now properly exposed to dynamically-loaded extension
2895 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002896
2897- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2898 Don't define MS_SYNC to be zero when it is undefined. Added missing
2899 prototypes in posixmodule.c.
2900
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002901- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002902 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002903
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002904- Fix largefile support on older NetBSD systems and OpenBSD by adding
2905 define for TELL64.
2906
2907
2908Tools and other miscellany
2909
2910- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2911
2912- freeze: The modulefinder now works with 2.0 opcodes.
2913
Tim Petersa3a3a032000-11-30 05:22:44 +00002914- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002915 Move hackery of sys.argv until after the Tk instance has been
2916 created, which allows the application-specific Tkinter
2917 initialization to be executed if present; also pass an explicit
2918 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002919
Jeremy Hylton1b618592000-09-26 05:32:36 +00002920
2921What's new in 2.0 beta 1?
2922=========================
2923
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002924Source Incompatibilities
2925------------------------
2926
2927None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2928such as single-argument append(), connect() and bind(), and changes to
2929str(long) and repr(float).
2930
2931
2932Binary Incompatibilities
2933------------------------
2934
2935- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2936with Python 2.0; these extensions will have to be rebuilt for Python
29372.0.
2938
2939- On Windows, attempting to import a third party extension built for
2940Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2941can do about this. Check your PYTHONPATH environment variable!
2942
2943- Python bytecode files (*.pyc and *.pyo) are not compatible between
2944releases.
2945
2946
2947Overview of Changes Since 1.6
2948-----------------------------
2949
2950There are many new modules (including brand new XML support through
2951the xml package, and i18n support through the gettext module); a list
2952of all new modules is included below. Lots of bugs have been fixed.
2953
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002954The process for making major new changes to the language has changed
2955since Python 1.6. Enhancements must now be documented by a Python
2956Enhancement Proposal (PEP) before they can be accepted.
2957
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002958There are several important syntax enhancements, described in more
2959detail below:
2960
2961 - Augmented assignment, e.g. x += 1
2962
2963 - List comprehensions, e.g. [x**2 for x in range(10)]
2964
2965 - Extended import statement, e.g. import Module as Name
2966
2967 - Extended print statement, e.g. print >> file, "Hello"
2968
2969Other important changes:
2970
2971 - Optional collection of cyclical garbage
2972
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002973Python Enhancement Proposal (PEP)
2974---------------------------------
2975
2976PEP stands for Python Enhancement Proposal. A PEP is a design
2977document providing information to the Python community, or describing
2978a new feature for Python. The PEP should provide a concise technical
2979specification of the feature and a rationale for the feature.
2980
2981We intend PEPs to be the primary mechanisms for proposing new
2982features, for collecting community input on an issue, and for
2983documenting the design decisions that have gone into Python. The PEP
2984author is responsible for building consensus within the community and
2985documenting dissenting opinions.
2986
2987The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002988
2989Augmented Assignment
2990--------------------
2991
2992This must have been the most-requested feature of the past years!
2993Eleven new assignment operators were added:
2994
Guido van Rossume905e952000-09-05 12:42:46 +00002995 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002996
2997For example,
2998
2999 A += B
3000
3001is similar to
3002
3003 A = A + B
3004
3005except that A is evaluated only once (relevant when A is something
3006like dict[index].attr).
3007
3008However, if A is a mutable object, A may be modified in place. Thus,
3009if A is a number or a string, A += B has the same effect as A = A+B
3010(except A is only evaluated once); but if a is a list, A += B has the
3011same effect as A.extend(B)!
3012
3013Classes and built-in object types can override the new operators in
3014order to implement the in-place behavior; the not-in-place behavior is
3015used automatically as a fallback when an object doesn't implement the
3016in-place behavior. For classes, the method name is derived from the
3017method name for the corresponding not-in-place operator by inserting
3018an 'i' in front of the name, e.g. __iadd__ implements in-place
3019__add__.
3020
3021Augmented assignment was implemented by Thomas Wouters.
3022
3023
3024List Comprehensions
3025-------------------
3026
3027This is a flexible new notation for lists whose elements are computed
3028from another list (or lists). The simplest form is:
3029
3030 [<expression> for <variable> in <sequence>]
3031
Guido van Rossum56db0952000-09-06 23:34:25 +00003032For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003033This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003034
3035You can also add a condition:
3036
3037 [<expression> for <variable> in <sequence> if <condition>]
3038
3039For example, [w for w in words if w == w.lower()] would yield the list
3040of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003041than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003042
3043You can also have nested for loops and more than one 'if' clause. For
3044example, here's a function that flattens a sequence of sequences::
3045
3046 def flatten(seq):
3047 return [x for subseq in seq for x in subseq]
3048
3049 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3050
3051This prints
3052
3053 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3054
3055List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003056Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003057
3058
3059Extended Import Statement
3060-------------------------
3061
3062Many people have asked for a way to import a module under a different
3063name. This can be accomplished like this:
3064
3065 import foo
3066 bar = foo
3067 del foo
3068
3069but this common idiom gets old quickly. A simple extension of the
3070import statement now allows this to be written as follows:
3071
3072 import foo as bar
3073
3074There's also a variant for 'from ... import':
3075
3076 from foo import bar as spam
3077
3078This also works with packages; e.g. you can write this:
3079
3080 import test.regrtest as regrtest
3081
3082Note that 'as' is not a new keyword -- it is recognized only in this
3083context (this is only possible because the syntax for the import
3084statement doesn't involve expressions).
3085
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003086Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003087
3088
3089Extended Print Statement
3090------------------------
3091
3092Easily the most controversial new feature, this extension to the print
3093statement adds an option to make the output go to a different file
3094than the default sys.stdout.
3095
3096For example, to write an error message to sys.stderr, you can now
3097write:
3098
3099 print >> sys.stderr, "Error: bad dog!"
3100
3101As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003102evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003103
3104 print >> None, "Hello world"
3105
3106is equivalent to
3107
3108 print "Hello world"
3109
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003110Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003111
3112
3113Optional Collection of Cyclical Garbage
3114---------------------------------------
3115
3116Python is now equipped with a garbage collector that can hunt down
3117cyclical references between Python objects. It's no replacement for
3118reference counting; in fact, it depends on the reference counts being
3119correct, and decides that a set of objects belong to a cycle if all
3120their reference counts can be accounted for from their references to
3121each other. This devious scheme was first proposed by Eric Tiedemann,
3122and brought to implementation by Neil Schemenauer.
3123
3124There's a module "gc" that lets you control some parameters of the
3125garbage collection. There's also an option to the configure script
3126that lets you enable or disable the garbage collection. In 2.0b1,
3127it's on by default, so that we (hopefully) can collect decent user
3128experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003129performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003130off by default in the final 2.0 release.
3131
3132
3133Smaller Changes
3134---------------
3135
3136A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3137map(None, seq1, seq2, ...) when the sequences have the same length;
3138i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3139the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003140zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003141
3142sys.version_info is a tuple (major, minor, micro, level, serial).
3143
3144Dictionaries have an odd new method, setdefault(key, default).
3145dict.setdefault(key, default) returns dict[key] if it exists; if not,
3146it sets dict[key] to default and returns that value. Thus:
3147
3148 dict.setdefault(key, []).append(item)
3149
3150does the same work as this common idiom:
3151
3152 if not dict.has_key(key):
3153 dict[key] = []
3154 dict[key].append(item)
3155
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003156There are two new variants of SyntaxError that are raised for
3157indentation-related errors: IndentationError and TabError.
3158
3159Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3160escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003161
3162The limits on the size of expressions and file in Python source code
3163have been raised from 2**16 to 2**32. Previous versions of Python
3164were limited because the maximum argument size the Python VM accepted
3165was 2**16. This limited the size of object constructor expressions,
3166e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3167limit was raised thanks to a patch by Charles Waldman that effectively
3168fixes the problem. It is now much more likely that you will be
3169limited by available memory than by an arbitrary limit in Python.
3170
3171The interpreter's maximum recursion depth can be modified by Python
3172programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3173limit is the maximum number of recursive calls that can be made by
3174Python code. The limit exists to prevent infinite recursion from
3175overflowing the C stack and causing a core dump. The default value is
31761000. The maximum safe value for a particular platform can be found
3177by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003178
3179New Modules and Packages
3180------------------------
3181
3182atexit - for registering functions to be called when Python exits.
3183
3184imputil - Greg Stein's alternative API for writing custom import
3185hooks.
3186
3187pyexpat - an interface to the Expat XML parser, contributed by Paul
3188Prescod.
3189
3190xml - a new package with XML support code organized (so far) in three
3191subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3192would fill a volume. There's a special feature whereby a
3193user-installed package named _xmlplus overrides the standard
3194xmlpackage; this is intended to give the XML SIG a hook to distribute
3195backwards-compatible updates to the standard xml package.
3196
3197webbrowser - a platform-independent API to launch a web browser.
3198
3199
Guido van Rossume905e952000-09-05 12:42:46 +00003200Changed Modules
3201---------------
3202
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003203array -- new methods for array objects: count, extend, index, pop, and
3204remove
3205
3206binascii -- new functions b2a_hex and a2b_hex that convert between
3207binary data and its hex representation
3208
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003209calendar -- Many new functions that support features including control
3210over which day of the week is the first day, returning strings instead
3211of printing them. Also new symbolic constants for days of week,
3212e.g. MONDAY, ..., SUNDAY.
3213
3214cgi -- FieldStorage objects have a getvalue method that works like a
3215dictionary's get method and returns the value attribute of the object.
3216
3217ConfigParser -- The parser object has new methods has_option,
3218remove_section, remove_option, set, and write. They allow the module
3219to be used for writing config files as well as reading them.
3220
3221ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003222optionally support the RFC 959 REST command.
3223
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003224gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003225
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003226httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3227the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003228
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003229locale -- implement getdefaultlocale for Win32 and Macintosh
3230
3231marshal -- no longer dumps core when marshaling deeply nested or
3232recursive data structures
3233
3234os -- new functions isatty, seteuid, setegid, setreuid, setregid
3235
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003236os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3237support under Unix.
3238
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003239os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003240
3241os.path -- fix semantics of os.path.commonprefix
3242
3243smtplib -- support for sending very long messages
3244
3245socket -- new function getfqdn()
3246
3247readline -- new functions to read, write and truncate history files.
3248The readline section of the library reference manual contains an
3249example.
3250
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003251select -- add interface to poll system call
3252
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003253shutil -- new copyfileobj function
3254
3255SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3256HTTP server.
3257
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003258Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003259
3260urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003261e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003262
3263whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003264
3265
3266Obsolete Modules
3267----------------
3268
3269None. However note that 1.6 made a whole slew of modules obsolete:
3270stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3271poly, zmod, strop, util, whatsound.
3272
3273
3274Changed, New, Obsolete Tools
3275----------------------------
3276
Tim Peters8b092332000-09-05 20:15:25 +00003277None.
Guido van Rossume905e952000-09-05 12:42:46 +00003278
3279
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003280C-level Changes
3281---------------
3282
3283Several cleanup jobs were carried out throughout the source code.
3284
3285All C code was converted to ANSI C; we got rid of all uses of the
3286Py_PROTO() macro, which makes the header files a lot more readable.
3287
3288Most of the portability hacks were moved to a new header file,
3289pyport.h; several other new header files were added and some old
3290header files were removed, in an attempt to create a more rational set
3291of header files. (Few of these ever need to be included explicitly;
3292they are all included by Python.h.)
3293
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003294Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003295and Win64, especially for the new Intel Itanium processor. Mick also
3296added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003297
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003298The C APIs to return an object's size have been update to consistently
3299use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3300previous versions, the abstract interfaces used PyXXX_Length and the
3301concrete interfaces used PyXXX_Size. The old names,
3302e.g. PyObject_Length, are still available for backwards compatibility
3303at the API level, but are deprecated.
3304
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003305The PyOS_CheckStack function has been implemented on Windows by
3306Fredrik Lundh. It prevents Python from failing with a stack overflow
3307on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003308
3309The GC changes resulted in creation of two new slots on object,
3310tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003311the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003312
3313The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003314C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003315
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003316PyErr_Format has been updated to automatically calculate the size of
3317the buffer needed to hold the formatted result string. This change
3318prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003319
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003320New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003321
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003322PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3323that are the same as their non-Ex counterparts except they take an
3324extra flag argument that tells them to close the file when done.
3325
3326XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003327
Tim Peters8b092332000-09-05 20:15:25 +00003328
3329Windows Changes
3330---------------
3331
3332New popen2/popen3/peopen4 in os module (see Changed Modules above).
3333
3334os.popen is much more usable on Windows 95 and 98. See Microsoft
3335Knowledge Base article Q150956. The Win9x workaround described there
3336is implemented by the new w9xpopen.exe helper in the root of your
3337Python installation. Note that Python uses this internally; it is not
3338a standalone program.
3339
3340Administrator privileges are no longer required to install Python
3341on Windows NT or Windows 2000. If you have administrator privileges,
3342Python's registry info will be written under HKEY_LOCAL_MACHINE.
3343Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003344under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003345uses of Python, but will prevent some advanced uses from working
3346(for example, running a Python script as an NT service, or possibly
3347from CGI).
3348
3349[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3350installer; instead, it installs the needed Tcl/Tk files directly in the
3351Python directory. If you already have a Tcl/Tk installation, this
3352wastes some disk space (about 4 Megs) but avoids problems with
3353conflicting Tcl/Tk installations, and makes it much easier for Python
3354to ensure that Tcl/Tk can find all its files.
3355
3356[This was new in 1.6] The Windows installer now installs by default in
3357\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3358
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003359
3360Updates to the changes between 1.5.2 and 1.6
3361--------------------------------------------
3362
3363The 1.6 NEWS file can't be changed after the release is done, so here
3364is some late-breaking news:
3365
3366New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3367and changes to getlocale() and setlocale().
3368
3369The new module is now enabled per default.
3370
3371It is not true that the encodings codecs cannot be used for normal
3372strings: the string.encode() (which is also present on 8-bit strings
3373!) allows using them for 8-bit strings too, e.g. to convert files from
3374cp1252 (Windows) to latin-1 or vice-versa.
3375
3376Japanese codecs are available from Tamito KAJIYAMA:
3377http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3378
3379
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003380======================================================================