blob: 62a482860769830623c73bfde14e864d59793390 [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
Neil Schemenauer9344b142002-04-12 23:00:08 +0000130- The type of tp_free has been changed from "void (*)(PyObject *)" to
131 "void (*)(void *)".
132
133- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
134
Guido van Rossum0986d822002-04-08 01:38:42 +0000135- A type can now inherit its metatype from its base type. Previously,
136 when PyType_Ready() was called, if ob_type was found to be NULL, it
137 was always set to &PyType_Type; now it is set to base->ob_type,
138 where base is tp_base, defaulting to &PyObject_Type.
139
140- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
141
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000142- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
143 functions will be allocated using pymalloc if it is enabled. These
144 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
145 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
146 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
147 PyCore_* family of APIs have been removed.
148
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000149- The "u#" parser marker will now pass through Unicode object as-is
150 without going through the buffer API.
151
Martin v. Löwis7198a522002-01-01 19:59:11 +0000152- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
153
Tim Peters10a3bb52001-12-25 19:07:38 +0000154- An old #define of ANY as void has been removed from pyport.h. This
155 hasn't been used since Python's pre-ANSI days, and the #define has
156 been marked as obsolete since then. SF bug 495548 says it created
157 conflicts with other packages, so keeping it around wasn't harmless.
158
Tim Petersaf8446f2001-12-21 21:36:50 +0000159- Because Python's magic number scheme broke on January 1st, we decided
160 to stop Python development. Thanks for all the fish!
161
Tim Petersfb05db22002-03-11 00:24:00 +0000162- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000163 scheme to a new one. See Python/import.c for details.
164
Tim Petersaf8446f2001-12-21 21:36:50 +0000165New platforms
166
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000167- GNU/Hurd is now supported.
168
Tim Petersaf8446f2001-12-21 21:36:50 +0000169Tests
170
171Windows
172
Guido van Rossum181e41a2002-04-06 00:23:25 +0000173- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
174
Tim Peters33187922002-04-04 20:02:04 +0000175- The installer now installs Start menu shortcuts under (the local
176 equivalent of) "All Users" when doing an Admin install.
177
Tim Petersfb05db22002-03-11 00:24:00 +0000178- file.truncate([newsize]) now works on Windows for all newsize values.
179 It used to fail if newsize didn't fit in 32 bits, reflecting a
180 limitation of MS _chsize (which is no longer used).
181
Tim Petersab034fa2002-02-01 11:27:43 +0000182- os.waitpid() is now implemented for Windows, and can be used to block
183 until a specified process exits. This is similar to, but not exactly
184 the same as, os.waitpid() on POSIX systems. If you're waiting for
185 a specific process whose pid was obtained from one of the spawn()
186 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000187 See the docs for details. The docs were changed to clarify that
188 spawn functions return, and waitpid requires, a process handle on
189 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000190
Tim Peters11bd9942002-02-01 00:52:29 +0000191- New tempfile.TemporaryFile implementation for Windows: this doesn't
192 need a TemproraryFileWrapper wrapper anymore, and should be immune
193 to a nasty problem: before 2.3, if you got a temp file on Windows, it
194 got wrapped in an object whose close() method first closed the
195 underlying file, then deleted the file. This usually worked fine.
196 However, the spawn family of functions on Windows create (at a low C
197 level) the same set of open files in the spawned process Q as were
198 open in the spawning process P. If a temp file f was among them, then
199 doing f.close() in P first closed P's C-level file handle on f, but Q's
200 C-level file handle on f remained open, so the attempt in P to delete f
201 blew up with a "Permission denied" error (Windows doesn't allow
202 deleting open files). This was surprising, subtle, and difficult to
203 work around.
204
205- The os module now exports all the symbolic constants usable with the
206 low-level os.open() on Windows: the new constants in 2.3 are
207 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
208 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
209 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
210 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
211 (so specify both if you want both; note that neither is useful unless
212 specified with O_CREAT too).
213
Tim Petersaf8446f2001-12-21 21:36:50 +0000214Mac
215
216
Tim Peters909c0912001-12-14 23:16:18 +0000217What's New in Python 2.2 final?
218Release date: 21-Dec-2001
219===============================
220
221Type/class unification and new-style classes
222
Barry Warsaw52acb492001-12-21 20:04:22 +0000223- pickle.py, cPickle: allow pickling instances of new-style classes
224 with a custom metaclass.
225
Tim Peters909c0912001-12-14 23:16:18 +0000226Core and builtins
227
Barry Warsaw52acb492001-12-21 20:04:22 +0000228- weakref proxy object: when comparing, unwrap both arguments if both
229 are proxies.
230
Tim Peters909c0912001-12-14 23:16:18 +0000231Extension modules
232
Barry Warsaw52acb492001-12-21 20:04:22 +0000233- binascii.b2a_base64(): fix a potential buffer overrun when encoding
234 very short strings.
235
236- cPickle: the obscure "fast" mode was suspected of causing stack
237 overflows on the Mac. Hopefully fixed this by setting the recursion
238 limit much smaller. If the limit is too low (it only affects
239 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
240 when compiling cPickle.c (or in pyconfig.h).
241
Tim Peters909c0912001-12-14 23:16:18 +0000242Library
243
Barry Warsaw52acb492001-12-21 20:04:22 +0000244- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
245 close or delete time).
246
247- rfc822.py: fixed a bug where the address '<>' was converted to None
248 instead of an empty string (also fixes the email.Utils module).
249
250- xmlrpclib.py: version 1.0.0; uses precision for doubles.
251
252- test suite: the pickle and cPickle tests were not executing any code
253 when run from the standard regresssion test.
254
Tim Peters909c0912001-12-14 23:16:18 +0000255Tools/Demos
256
257Build
258
259C API
260
261New platforms
262
263Tests
264
265Windows
266
Barry Warsaw52acb492001-12-21 20:04:22 +0000267- distutils package: fixed broken Windows installers (bdist_wininst).
268
269- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
270 instances are deleted at process exit time.
271
272- socket.py: prevent mysterious warnings when socket instances are
273 deleted at process exit time.
274
275- posixmodule.c: fix a Windows crash with stat() of a filename ending
276 in backslash.
277
Tim Peters909c0912001-12-14 23:16:18 +0000278Mac
279
Barry Warsaw52acb492001-12-21 20:04:22 +0000280- The Carbon toolbox modules have been upgraded to Universal Headers
281 3.4, and experimental CoreGraphics and CarbonEvents modules have
282 been added. All only for framework-enabled MacOSX.
283
Tim Peters909c0912001-12-14 23:16:18 +0000284
Tim Peters6272dfd2001-12-13 19:34:00 +0000285What's New in Python 2.2c1?
286Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000287===========================
288
289Type/class unification and new-style classes
290
Barry Warsaw06557452001-12-14 20:47:12 +0000291- Guido's tutorial introduction to the new type/class features has
292 been extensively updated. See
293
294 http://www.python.org/2.2/descrintro.html
295
296 That remains the primary documentation in this area.
297
Guido van Rossum33bab012001-12-05 22:45:48 +0000298- Fixed a leak: instance variables declared with __slots__ were never
299 deleted!
300
Guido van Rossum4b800852001-12-03 00:54:52 +0000301- The "delete attribute" method of descriptor objects is called
302 __delete__, not __del__. In previous releases, it was mistakenly
303 called __del__, which created an unfortunate overloading condition
304 with finalizers. (The "get attribute" and "set attribute" methods
305 are still called __get__ and __set__, respectively.)
306
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000307- Some subtle issues with the super built-in were fixed:
308
309 (a) When super itself is subclassed, its __get__ method would still
310 return an instance of the base class (i.e., of super).
311
312 (b) super(C, C()).__class__ would return C rather than super. This
313 is confusing. To fix this, I decided to change the semantics of
314 super so that it only applies to code attributes, not to data
315 attributes. After all, overriding data attributes is not
316 supported anyway.
317
318 (c) The __get__ method didn't check whether the argument was an
319 instance of the type used in creation of the super instance.
320
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000321- Previously, hash() of an instance of a subclass of a mutable type
322 (list or dictionary) would return some value, rather than raising
323 TypeError. This has been fixed. Also, directly calling
324 dict.__hash__ and list.__hash__ now raises the same TypeError
325 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000326
Guido van Rossumd331cb52001-12-05 19:46:42 +0000327- New-style objects now support deleting their __dict__. This is for
328 all intents and purposes equivalent to assigning a brand new empty
329 dictionary, but saves space if the object is not used further.
330
Tim Petersb3c9af12001-11-17 00:21:57 +0000331Core and builtins
332
Tim Peters3caca232001-12-06 06:23:26 +0000333- -Qnew now works as documented in PEP 238: when -Qnew is passed on
334 the command line, all occurrences of "/" use true division instead
335 of classic division. See the PEP for details. Note that "all"
336 means all instances in library and 3rd-party modules, as well as in
337 your own code. As the PEP says, -Qnew is intended for use only in
338 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000339 Note that test_coercion.py in the standard Python test suite fails
340 under -Qnew; this is expected, and won't be repaired until true
341 division becomes the default (in the meantime, test_coercion is
342 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000343
Fred Drake6c01e252001-12-14 17:08:12 +0000344- complex() now only allows the first argument to be a string
345 argument, and raises TypeError if either the second arg is a string
346 or if the second arg is specified when the first is a string.
347
Tim Petersb3c9af12001-11-17 00:21:57 +0000348Extension modules
349
Martin v. Löwis560da622001-11-24 09:24:51 +0000350- gc.get_referents was renamed to gc.get_referrers.
351
Tim Petersb3c9af12001-11-17 00:21:57 +0000352Library
353
Tim Peters25059d32001-12-07 20:35:43 +0000354- Functions in the os.spawn() family now release the global interpreter
355 lock around calling the platform spawn. They should always have done
356 this, but did not before 2.2c1. Multithreaded programs calling
357 an os.spawn function with P_WAIT will no longer block all Python threads
358 until the spawned program completes. It's possible that some programs
359 relies on blocking, although more likely by accident than by design.
360
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000361- webbrowser defaults to netscape.exe on OS/2 now.
362
Martin v. Löwis652e1912001-11-25 14:50:56 +0000363- Tix.ResizeHandle exposes detach_widget, hide, and show.
364
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000365- The charset alias windows_1252 has been added.
366
Barry Warsaw06557452001-12-14 20:47:12 +0000367- types.StringTypes is a tuple containing the defined string types;
368 usually this will be (str, unicode), but if Python was compiled
369 without Unicode support it will be just (str,).
370
371- The pulldom and minidom modules were synchronized to PyXML.
372
Tim Petersb3c9af12001-11-17 00:21:57 +0000373Tools/Demos
374
Barry Warsaw06557452001-12-14 20:47:12 +0000375- A new script called Tools/scripts/google.py was added, which fires
376 off a search on Google.
377
Tim Petersb3c9af12001-11-17 00:21:57 +0000378Build
379
Barry Warsaw06557452001-12-14 20:47:12 +0000380- Note that release builds of Python should arrange to define the
381 preprocessor symbol NDEBUG on the command line (or equivalent).
382 In the 2.2 pre-release series we tried to define this by magic in
383 Python.h instead, but it proved to cause problems for extension
384 authors. The Unix, Windows and Mac builds now all define NDEBUG in
385 release builds via cmdline (or equivalent) instead. Ports to
386 other platforms should do likewise.
387
Jack Jansen1999ef42001-12-06 21:47:20 +0000388- It is no longer necessary to use --with-suffix when building on a
389 case-insensitive file system (such as Mac OS X HFS+). In the build
390 directory an extension is used, but not in the installed python.
391
Tim Petersb3c9af12001-11-17 00:21:57 +0000392C API
393
Tim Petersf582b822001-12-11 18:51:08 +0000394- New function PyDict_MergeFromSeq2() exposes the builtin dict
395 constructor's logic for updating a dictionary from an iterable object
396 producing key-value pairs.
397
Tim Peterscffed4b2001-11-29 03:26:37 +0000398- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000399 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000400 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
401 dump core in some bad cases. This has been repaired. As a result,
402 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
403 previously went unchallenged.
404
Tim Petersb3c9af12001-11-17 00:21:57 +0000405New platforms
406
407Tests
408
409Windows
410
411Mac
412
Jack Jansenffa260f2001-12-06 21:14:00 +0000413- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
414 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000415
Barry Warsaw06557452001-12-14 20:47:12 +0000416- Changed logic for finding python home in Mac OS X framework Pythons.
417 Now sys.executable points to the executable again, in stead of to
418 the shared library. The latter is used only for locating the python
419 home.
420
421
Tim Peters84362bc2001-10-19 17:55:30 +0000422What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000423Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000424===========================
425
426Type/class unification and new-style classes
427
Guido van Rossum3d27df02001-11-15 20:27:54 +0000428- Multiple inheritance mixing new-style and classic classes in the
429 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000430
431 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000432 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000433
434 The MRO (method resolution order) for each base class is respected
435 according to its kind, but the MRO for the derived class is computed
436 using new-style MRO rules if any base clase is a new-style class.
437 This needs to be documented.
438
Tim Petersa427a2b2001-10-29 22:25:45 +0000439- The new builtin dictionary() constructor, and dictionary type, have
440 been renamed to dict. This reflects a decade of common usage.
441
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000442- dict() now accepts an iterable object producing 2-sequences. For
443 example, dict(d.items()) == d for any dictionary d. The argument,
444 and the elements of the argument, can be any iterable objects.
445
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000446- New-style classes can now have a __del__ method, which is called
447 when the instance is deleted (just like for classic classes).
448
Guido van Rossum12d955c2001-10-26 14:56:06 +0000449- Assignment to object.__dict__ is now possible, for objects that are
450 instances of new-style classes that have a __dict__ (unless the base
451 class forbids it).
452
Guido van Rossumc8e56452001-10-22 00:43:43 +0000453- Methods of built-in types now properly check for keyword arguments
454 (formerly these were silently ignored). The only built-in methods
455 that take keyword arguments are __call__, __init__ and __new__.
456
Guido van Rossum86443212001-10-27 22:28:54 +0000457- The socket function has been converted to a type; see below.
458
Tim Peters84362bc2001-10-19 17:55:30 +0000459Core and builtins
460
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000461- Assignment to __debug__ raises SyntaxError at compile-time. This
462 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000463 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000464
Guido van Rossum12d955c2001-10-26 14:56:06 +0000465- Clarified the error messages for unsupported operands to an operator
466 (like 1 + '').
467
Tim Peters84362bc2001-10-19 17:55:30 +0000468Extension modules
469
Tim Peters5ebfd362001-11-13 23:11:19 +0000470- mmap has a new keyword argument, "access", allowing a uniform way for
471 both Windows and Unix users to create read-only, write-through and
472 copy-on-write memory mappings. This was previously possible only on
473 Unix. A new keyword argument was required to support this in a
474 uniform way because the mmap() signuatures had diverged across
475 platforms. Thanks to Jay T Miller for repairing this!
476
Tim Peters169ded02001-11-03 19:57:21 +0000477- By default, the gc.garbage list now contains only those instances in
478 unreachable cycles that have __del__ methods; in 2.1 it contained all
479 instances in unreachable cycles. "Instances" here has been generalized
480 to include instances of both new-style and old-style classes.
481
Guido van Rossum12d955c2001-10-26 14:56:06 +0000482- The socket module defines a new method for socket objects,
483 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000484 send() until all data has been sent. Also, the socket function has
485 been converted to a subclassable type, like list and tuple (etc.)
486 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000487
488- Various bugfixes to the curses module. There is now a test suite
489 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000490
Guido van Rossum692adf12001-10-30 03:03:03 +0000491- binascii.b2a_base64 no longer places an arbitrary restriction of 57
492 bytes on its input.
493
Tim Peters84362bc2001-10-19 17:55:30 +0000494Library
495
Tim Peters5ebfd362001-11-13 23:11:19 +0000496- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000497 convenience function.
498
Tim Peters75335872001-11-03 19:35:43 +0000499- Symbolic group names in regular expressions must be unique. For
500 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
501 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000502 Python 2.2 detects this error at regexp compilation time;
503 previously, the error went undetected, and results were
504 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
505 pattern.subn() methods have been rewritten in C. Also, an
506 experimental function/method finditer() has been added, which works
507 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000508
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000509- Tix exposes more commands through the classes DirSelectBox,
510 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
511 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
512 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
513
Tim Peters98791af2001-10-23 01:59:54 +0000514- Traceback objects are now scanned by cyclic garbage collection, so
515 cycles created by casual use of sys.exc_info() no longer cause
516 permanent memory leaks (provided garbage collection is enabled).
517
Guido van Rossum49192142001-10-24 20:51:44 +0000518- os.extsep -- a new variable needed by the RISCOS support. It is the
519 separator used by extensions, and is '.' on all platforms except
520 RISCOS, where it is '/'. There is no need to use this variable
521 unless you have a masochistic desire to port your code to RISCOS.
522
Barry Warsaw012852b2001-11-16 16:17:27 +0000523- mimetypes.py has optional support for non-standard, but commonly
524 found types. guess_type() and guess_extension() now accept an
525 optional `strict' flag, defaulting to true, which controls whether
526 recognize non-standard types or not. A few non-standard types we
527 know about have been added. Also, when run as a script, there are
528 new -l and -e options.
529
530- statcache is now deprecated.
531
532- email.Utils.formatdate() now produces the preferred RFC 2822 style
533 dates with numeric timezones (it used to produce obsolete dates
534 hard coded to "GMT" timezone). An optional `localtime' flag is
535 added to produce dates in the local timezone, with daylight savings
536 time properly taken into account.
537
538- In pickle and cPickle, instead of masking errors in load() by
539 transforming them into SystemError, we let the original exception
540 propagate out. Also, implement support for __safe_for_unpickling__
541 in pickle, as it already was supported in cPickle.
542
Tim Peters84362bc2001-10-19 17:55:30 +0000543Tools/Demos
544
545Build
546
Barry Warsaw012852b2001-11-16 16:17:27 +0000547- The dbm module is built using libdb1 if available. The bsddb module
548 is built with libdb3 if available.
549
550- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
551
Tim Peters84362bc2001-10-19 17:55:30 +0000552C API
553
Tim Peters1fc240e2001-10-26 05:06:50 +0000554- New function PySequence_Fast_GET_SIZE() returns the size of a non-
555 NULL result from PySequence_Fast(), more quickly than calling
556 PySequence_Size().
557
Barry Warsaw012852b2001-11-16 16:17:27 +0000558- New argument unpacking function PyArg_UnpackTuple() added.
559
560- New functions PyObject_CallFunctionObjArgs() and
561 PyObject_CallMethodObjArgs() have been added to make it more
562 convenient and efficient to call functions and methods from C.
563
564- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
565 possible that this will propagate errors it didn't before.
566
567- New function PyObject_CheckReadBuffer(), which returns true if its
568 argument supports the single-segment readable buffer interface.
569
Tim Peters84362bc2001-10-19 17:55:30 +0000570New platforms
571
Guido van Rossum86443212001-10-27 22:28:54 +0000572- We've finally confirmed that this release builds on HP-UX 11.00,
573 *with* threads, and passes the test suite.
574
Tim Peters7a33d8b2001-11-05 02:51:07 +0000575- Thanks to a series of patches from Michael Muller, Python may build
576 again under OS/2 Visual Age C++.
577
Guido van Rossum49192142001-10-24 20:51:44 +0000578- Updated RISCOS port by Dietmar Schwertberger.
579
Tim Peters84362bc2001-10-19 17:55:30 +0000580Tests
581
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000582- Added a test script for the curses module. It isn't run automatically;
583 regrtest.py must be run with '-u curses' to enable it.
584
Tim Peters84362bc2001-10-19 17:55:30 +0000585Windows
586
Barry Warsaw012852b2001-11-16 16:17:27 +0000587Mac
588
589- PythonScript has been moved to unsupported and is slated to be
590 removed completely in the next release.
591
592- It should now be possible to build applets that work on both OS9 and
593 OSX.
594
595- The core is now linked with CoreServices not Carbon; as a side
596 result, default 8bit encoding on OSX is now ASCII.
597
598- Python should now build on OSX 10.1.1
599
Tim Peters84362bc2001-10-19 17:55:30 +0000600
Tim Petersabf925f2001-09-28 21:53:42 +0000601What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000602Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000603===========================
604
605Type/class unification and new-style classes
606
Guido van Rossum687ae002001-10-15 22:03:32 +0000607- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000608 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000609 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000610 remains: the __dict__ of a new-style class is a read-only proxy; you
611 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000612 __defined__ attribute of new-style types no longer exists, for lack
613 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000614 future a __cache__ may be resurrected with a similar function, if I
615 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000616
Tim Peters1c9ca872001-10-04 06:43:12 +0000617- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
618 always returned None, even when there was a class docstring).
619
620- doctest now finds and runs docstrings attached to new-style classes,
621 class methods, static methods, and properties.
622
Guido van Rossum9074ef62001-10-16 21:34:49 +0000623Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000624
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000625- A very subtle syntactical pitfall in list comprehensions was fixed.
626 For example: [a+b for a in 'abc', for b in 'def']. The comma in
627 this example is a mistake. Previously, this would silently let 'a'
628 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
629 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
630 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
631 Note that [a for a in <singleton>] is a convoluted way to say
632 [<singleton>] anyway, so it's not like any expressiveness is lost.
633
Guido van Rossum9074ef62001-10-16 21:34:49 +0000634- getattr(obj, name, default) now only catches AttributeError, as
635 documented, rather than returning the default value for all
636 exceptions (which could mask bugs in a __getattr__ hook, for
637 example).
638
Fred Drakecb7a6b52001-10-22 18:41:51 +0000639- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000640 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000641 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000642 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000643
Guido van Rossum1c486092001-10-19 02:05:35 +0000644- unicode(obj) now behaves more like str(obj), accepting arbitrary
645 objects, and calling a __unicode__ method if it exists.
646 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000647 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000648
Barry Warsawf6fb1712001-10-19 05:35:40 +0000649- isinstance() now allows any object as the first argument and a
650 class, a type or something with a __bases__ tuple attribute for the
651 second argument. The second argument may also be a tuple of a
652 class, type, or something with __bases__, in which case isinstance()
653 will return true if the first argument is an instance of any of the
654 things contained in the second argument tuple. E.g.
655
656 isinstance(x, (A, B))
657
658 returns true if x is an instance of A or B.
659
Guido van Rossum9074ef62001-10-16 21:34:49 +0000660Extension modules
661
662- thread.start_new_thread() now returns the thread ID (previously None).
663
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000664- binascii has now two quopri support functions, a2b_qp and b2a_qp.
665
Guido van Rossumc524d952001-10-19 01:31:59 +0000666- readline now supports setting the startup_hook and the
667 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000668
Guido van Rossumc524d952001-10-19 01:31:59 +0000669- os and posix supports chroot(), setgroups() and unsetenv() where
670 available. The stat(), fstat(), statvfs() and fstatvfs() functions
671 now return "pseudo-sequences" -- the various fields can now be
672 accessed as attributes (e.g. os.stat("/").st_mtime) but for
673 backwards compatibility they also behave as a fixed-length sequence.
674 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000675 attributes.
676
677- time: localtime(), gmtime() and strptime() now return a
678 pseudo-sequence similar to the os.stat() return value, with
679 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000680
Guido van Rossum9074ef62001-10-16 21:34:49 +0000681- Decompression objects in the zlib module now accept an optional
682 second parameter to decompress() that specifies the maximum amount
683 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000684
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000685- optional SSL support in the socket module now exports OpenSSL
686 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
687 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000688 automatically seed its PRNG. Also, the keyfile and certfile
689 arguments to socket.ssl() are now optional.
690
691- posixmodule (and by extension, the os module on POSIX platforms) now
692 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000693
Guido van Rossum9074ef62001-10-16 21:34:49 +0000694Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000695
Tim Peters7402f792001-10-02 03:53:41 +0000696- doctest now excludes functions and classes not defined by the module
697 being tested, thanks to Tim Hochberg.
698
Fred Drakecb7a6b52001-10-22 18:41:51 +0000699- HotShot, a new profiler implemented using a C-based callback, has
700 been added. This substantially reduces the overhead of profiling,
701 but it is still quite preliminary. Support modules and
702 documentation will be added in upcoming releases (before 2.2 final).
703
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000704- profile now produces correct output in situations where an exception
705 raised in Python is cleared by C code (e.g. hasattr()). This used
706 to cause wrong output, including spurious claims of recursive
707 functions and attribution of time spent to the wrong function.
708
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000709 The code and documentation for the derived OldProfile and HotProfile
710 profiling classes was removed. The code hasn't worked for years (if
711 you tried to use them, they raised exceptions). OldProfile
712 intended to reproduce the behavior of the profiler Python used more
713 than 7 years ago, and isn't interesting anymore. HotProfile intended
714 to provide a faster profiler (but producing less information), and
715 that's a worthy goal we intend to meet via a different approach (but
716 without losing information).
717
Tim Peterscce092d2001-10-09 05:31:56 +0000718- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000719 a much better system-specific calibration constant. The constant can
720 now be specified in an instance constructor, or as a Profile class or
721 instance variable, instead of by editing profile.py's source code.
722 Calibration must still be done manually (see the docs for the profile
723 module).
724
725 Note that Profile.calibrate() must be overriden by subclasses.
726 Improving the accuracy required exploiting detailed knowledge of
727 profiler internals; the earlier method abstracted away the details
728 and measured a simplified model instead, but consequently computed
729 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000730
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000731- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000732 which indicates whether output is intended for the header 'Q'
733 encoding.
734
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000735- The SocketServer.ThreadingMixIn class now closes the request after
736 finish_request() returns. (Not when it errors out though.)
737
Barry Warsawf6fb1712001-10-19 05:35:40 +0000738- The nntplib module's NNTP.body() method has grown a `file' argument
739 to allow saving the message body to a file.
740
741- The email package has added a class email.Parser.HeaderParser which
742 only parses headers and does not recurse into the message's body.
743 Also, the module/class MIMEAudio has been added for representing
744 audio data (contributed by Anthony Baxter).
745
746- ftplib should be able to handle files > 2GB.
747
748- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
749 ON, and OFF.
750
Fred Drakecb7a6b52001-10-22 18:41:51 +0000751- xml.dom.minidom NodeList objects now support the length attribute
752 and item() method as required by the DOM specifications.
753
Guido van Rossumed554f62001-10-02 23:15:37 +0000754Tools/Demos
755
756- Demo/dns was removed. It no longer serves any purpose; a package
757 derived from it is now maintained by Anthony Baxter, see
758 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000759
Barry Warsawf6fb1712001-10-19 05:35:40 +0000760- The freeze tool has been made more robust, and two new options have
761 been added: -X and -E.
762
Tim Petersabf925f2001-09-28 21:53:42 +0000763Build
764
Barry Warsawf6fb1712001-10-19 05:35:40 +0000765- configure will use CXX in LINKCC if CXX is used to build main() and
766 the system requires to link a C++ main using the C++ compiler.
767
Tim Petersabf925f2001-09-28 21:53:42 +0000768C API
769
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000770- The documentation for the tp_compare slot is updated to require that
771 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
772 not correct. This is not yet enforced but will be enforced in
773 Python 2.3; even later, we may use -2 to indicate errors and +2 for
774 "NotImplemented". Right now, -1 should be used for an error return.
775
Tim Petersd38b1c72001-09-30 05:09:37 +0000776- PyLong_AsLongLong() now accepts int (as well as long) arguments.
777 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
778 as long) arguments.
779
Guido van Rossum3c288632001-10-16 21:13:49 +0000780- PyThread_start_new_thread() now returns a long int giving the thread
781 ID, if one can be calculated; it returns -1 for error, 0 if no
782 thread ID is calculated (this is an incompatible change, but only
783 the thread module used this API). This code has only really been
784 tested on Linux and Windows; other platforms please beware (and
785 report any bugs or strange behavior).
786
Guido van Rossum1c486092001-10-19 02:05:35 +0000787- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
788 input.
789
Tim Petersabf925f2001-09-28 21:53:42 +0000790New platforms
791
792Tests
793
794Windows
795
Tim Peters04cf1d32001-10-09 22:39:40 +0000796- Installer: If you install IDLE, and don't disable file-extension
797 registration, a new "Edit with IDLE" context (right-click) menu entry
798 is created for .py and .pyw files.
799
Tim Peters1ce3cf72001-10-01 17:58:40 +0000800- The signal module now supports SIGBREAK on Windows, thanks to Steven
801 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
802 action remains to call Win32 ExitProcess(). This can be changed via
803 signal.signal(). For example:
804
805 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
806 # (SIGINT) behavior.
807 import signal
808 signal.signal(signal.SIGBREAK,
809 signal.default_int_handler)
810
811 try:
812 while 1:
813 pass
814 except KeyboardInterrupt:
815 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
816 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
817 # program without the possibility for any Python-level cleanup).
818 print "Clean exit"
819
Tim Petersabf925f2001-09-28 21:53:42 +0000820
Tim Petersb07352e2001-09-08 01:25:47 +0000821What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000822Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000823===========================
824
Guido van Rossum808eea72001-09-25 04:15:41 +0000825Type/class unification and new-style classes
826
827- pydoc and inspect are now aware of new-style classes;
828 e.g. help(list) at the interactive prompt now shows proper
829 documentation for all operations on list objects.
830
831- Applications using Jim Fulton's ExtensionClass module can now safely
832 be used with Python 2.2. In particular, Zope 2.4.1 now works with
833 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
834 examples also work again. It is hoped that Gtk and Boost also work
835 with 2.2a4 and beyond. (If you can confirm this, please write
836 webmaster@python.org; if there are still problems, please open a bug
837 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000838
Tim Peters66c1a522001-09-24 21:17:50 +0000839- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
840 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
841 in the constructed property object. fget, fset and fdel weren't
842 discoverable from Python in 2.2a3. __doc__ is new, and allows to
843 associate a docstring with a property.
844
Guido van Rossum808eea72001-09-25 04:15:41 +0000845- Comparison overloading is now more completely implemented. For
846 example, a str subclass instance can properly be compared to a str
847 instance, and it can properly overload comparison. Ditto for most
848 other built-in object types.
849
850- The repr() of new-style classes has changed; instead of <type
851 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
852 *except* for built-in types, which are still rendered as <type
853 'Foo'> (to avoid upsetting existing code that might parse or
854 otherwise rely on repr() of certain type objects).
855
856- The repr() of new-style objects is now always <Foo object at XXX>;
857 previously, it was sometimes <Foo instance at XXX>.
858
859- For new-style classes, what was previously called __getattr__ is now
860 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000861 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000862 one in classic classes is defined which is called only if regular
863 attribute access raises AttributeError; to catch *all* attribute
864 access, you can use __getattribute__ (for new-style classes). If
865 both are defined, __getattribute__ is called first, and if it raises
866 AttributeError, __getattr__ is called.
867
868- The __class__ attribute of new-style objects can be assigned to.
869 The new class must have the same C-level object layout as the old
870 class.
871
872- The builtin file type can be subclassed now. In the usual pattern,
873 "file" is the name of the builtin type, and file() is a new builtin
874 constructor, with the same signature as the builtin open() function.
875 file() is now the preferred way to open a file.
876
877- Previously, __new__ would only see sequential arguments passed to
878 the type in a constructor call; __init__ would see both sequential
879 and keyword arguments. This made no sense whatsoever any more, so
880 now both __new__ and __init__ see all arguments.
881
882- Previously, hash() applied to an instance of a subclass of str or
883 unicode always returned 0. This has been repaired.
884
885- Previously, an operation on an instance of a subclass of an
886 immutable type (int, long, float, complex, tuple, str, unicode),
887 where the subtype didn't override the operation (and so the
888 operation was handled by the builtin type), could return that
889 instance instead a value of the base type. For example, if s was of
890 a str sublass type, s[:] returned s as-is. Now it returns a str
891 with the same value as s.
892
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000893- Provisional support for pickling new-style objects has been added.
894
Guido van Rossum808eea72001-09-25 04:15:41 +0000895Core
896
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000897- file.writelines() now accepts any iterable object producing strings.
898
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000899- PyUnicode_FromEncodedObject() now works very much like
900 PyObject_Str(obj) in that it tries to use __str__/tp_str
901 on the object if the object is not a string or buffer. This
902 makes unicode() behave like str() when applied to non-string/buffer
903 objects.
904
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000905- PyFile_WriteObject now passes Unicode objects to the file's write
906 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000907 of a print statement must support Unicode objects, i.e. they must
908 at least convert them into ASCII strings.
909
Guido van Rossum624c8af2001-09-18 15:21:04 +0000910- Thread scheduling on Solaris should be improved; it is no longer
911 necessary to insert a small sleep at the start of a thread in order
912 to let other runnable threads be scheduled.
913
Tim Petersb07352e2001-09-08 01:25:47 +0000914Library
915
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000916- StringIO.StringIO instances and cStringIO.StringIO instances support
917 read character buffer compatible objects for their .write() methods.
918 These objects are converted to strings and then handled as such
919 by the instances.
920
Barry Warsaw2f600732001-09-24 04:28:10 +0000921- The "email" package has been added. This is basically a port of the
922 mimelib package <http://sf.net/projects/mimelib> with API changes
923 and some implementations updated to use iterators and generators.
924
Tim Peters8a9c2842001-09-22 21:30:22 +0000925- difflib.ndiff() and difflib.Differ.compare() are generators now. This
926 restores the ability of Tools/scripts/ndiff.py to start producing output
927 before the entire comparison is complete.
928
Barry Warsaw58b072d2001-09-22 04:44:21 +0000929- StringIO.StringIO instances and cStringIO.StringIO instances support
930 iteration just like file objects (i.e. their .readline() method is
931 called for each iteration until it returns an empty string).
932
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000933- The codecs module has grown four new helper APIs to access
934 builtin codecs: getencoder(), getdecoder(), getreader(),
935 getwriter().
936
Guido van Rossum624c8af2001-09-18 15:21:04 +0000937- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
938 simplifies writing XML RPC servers.
939
Barry Warsaw647d5e82001-09-28 17:01:02 +0000940- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000941 after interpretation of symbolic links. On non-Unix systems, this
942 is an alias for os.path.abspath().
943
Tim Peters16a77ad2001-09-08 04:00:12 +0000944- operator.indexOf() (PySequence_Index() in the C API) now works with any
945 iterable object.
946
Guido van Rossum624c8af2001-09-18 15:21:04 +0000947- smtplib now supports various authentication and security features of
948 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000949
Guido van Rossum624c8af2001-09-18 15:21:04 +0000950- hmac: a new module implementing keyed hashing for message
951 authentication.
952
953- mimetypes now recognizes more extensions and file types. At the
954 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000955
Guido van Rossum624c8af2001-09-18 15:21:04 +0000956- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000957 Python 2.2 bytecode generation. It has also been promoted from a
958 Tool to a standard library package. (Tools/compiler still exists as
959 a sample driver.)
960
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000961Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000962
Tim Petersb07352e2001-09-08 01:25:47 +0000963Build
964
Guido van Rossum624c8af2001-09-18 15:21:04 +0000965- Large file support (LFS) is now automatic when the platform supports
966 it; no more manual configuration tweaks are needed. On Linux, at
967 least, it's possible to have a system whose C library supports large
968 files but whose kernel doesn't; in this case, large file support is
969 still enabled but doesn't do you any good unless you upgrade your
970 kernel or share your Python executable with another system whose
971 kernel has large file support.
972
973- The configure script now supplies plausible defaults in a
974 cross-compilation environment. This doesn't mean that the supplied
975 values are always correct, or that cross-compilation now works
976 flawlessly -- but it's a first step (and it shuts up most of
977 autoconf's warnings about AC_TRY_RUN).
978
979- The Unix build is now a bit less chatty, courtesy of the parser
980 generator. The build is completely silent (except for errors) when
981 using "make -s", thanks to a -q option to setup.py.
982
Tim Petersb07352e2001-09-08 01:25:47 +0000983C API
984
Guido van Rossum624c8af2001-09-18 15:21:04 +0000985- The "structmember" API now supports some new flag bits to deny read
986 and/or write access to attributes in restricted execution mode.
987
Tim Petersb07352e2001-09-08 01:25:47 +0000988New platforms
989
Guido van Rossum624c8af2001-09-18 15:21:04 +0000990- Compaq's iPAQ handheld, running the "familiar" Linux distribution
991 (http://familiar.handhelds.org).
992
Tim Petersb07352e2001-09-08 01:25:47 +0000993Tests
994
Tim Peters8a9c2842001-09-22 21:30:22 +0000995- The "classic" standard tests, which work by comparing stdout to
996 an expected-output file under Lib/test/output/, no longer stop at
997 the first mismatch. Instead the test is run to completion, and a
998 variant of ndiff-style comparison is used to report all differences.
999 This is much easier to understand than the previous style of reporting.
1000
1001- The unittest-based standard tests now use regrtest's test_main()
1002 convention, instead of running as a side-effect of merely being
1003 imported. This allows these tests to be run in more natural and
1004 flexible ways as unittests, outside the regrtest framework.
1005
1006- regrtest.py is much better integrated with unittest and doctest now,
1007 especially in regard to reporting errors.
1008
Tim Petersb07352e2001-09-08 01:25:47 +00001009Windows
1010
Guido van Rossum624c8af2001-09-18 15:21:04 +00001011- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001012 that support it (NTFS under Windows 2000). See "What's New in
1013 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001014
Tim Petersb07352e2001-09-08 01:25:47 +00001015
Tim Petersedc99312001-08-22 21:36:50 +00001016What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001017Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001018===========================
1019
1020Core
1021
Tim Peters9fffa3e2001-09-04 05:14:19 +00001022- Conversion of long to float now raises OverflowError if the long is too
1023 big to represent as a C double.
1024
Tim Peters32f453e2001-09-03 08:35:41 +00001025- The 3-argument builtin pow() no longer allows a third non-None argument
1026 if either of the first two arguments is a float, or if both are of
1027 integer types and the second argument is negative (in which latter case
1028 the arguments are converted to float, so this is really the same
1029 restriction).
1030
Tim Peters5d2b77c2001-09-03 05:47:38 +00001031- The builtin dir() now returns more information, and sometimes much
1032 more, generally naming all attributes of an object, and all attributes
1033 reachable from the object via its class, and from its class's base
1034 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1035 an empty list. In 2.2a3,
1036
1037 >>> dir([])
1038 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1039 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1040 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1041 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1042 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1043 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1044 'reverse', 'sort']
1045
1046 dir(module) continues to return only the module's attributes, though.
1047
Tim Petersbdee63f2001-09-02 03:40:59 +00001048- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001049 than raising OverflowError. This is a partial implementation of PEP
1050 237. You can use -Wdefault::OverflowWarning to enable a warning for
1051 this situation, and -Werror::OverflowWarning to revert to the old
1052 OverflowError exception.
1053
Guido van Rossum61c345f2001-09-04 03:26:15 +00001054- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001055 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001056 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1057 -Qold, meaning the / operator has its classic meaning and no
1058 warnings are issued. Using -Qwarn issues a run-time warning about
1059 all uses of classic division for int and long arguments; -Qwarnall
1060 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001061 (for use with fixdiv.py).
1062 [Note: the remainder of this paragraph (preserved below) became
1063 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1064 <obsolete>
1065 Using -Qnew is questionable; it turns on new division by default, but
1066 only in the __main__ module. You can usefully combine -Qwarn or
1067 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1068 warns about classic division everywhere else.
1069 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001070
Tim Petersbdee63f2001-09-02 03:40:59 +00001071- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001072 long, float, str, unicode, and tuple. (The types complex, list and
1073 dictionary can also be subclassed; this was introduced earlier.)
1074 Note that restrictions apply when subclassing immutable built-in
1075 types: you can only affect the value of the instance by overloading
1076 __new__. You can add mutable attributes, and the subclass instances
1077 will have a __dict__ attribute, but you cannot change the "value"
1078 (as implemented by the base class) of an immutable subclass instance
1079 once it is created.
1080
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001081- The dictionary constructor now takes an optional argument, a
1082 mapping-like object, and initializes the dictionary from its
1083 (key, value) pairs.
1084
Tim Petersbdee63f2001-09-02 03:40:59 +00001085- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001086 "cooperative super calls" in a multiple inheritance setting. For an
1087 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1088
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001089- A new built-in type, property, has been added. This enables the
1090 creation of "properties". These are attributes implemented by
1091 getter and setter functions (or only one of these for read-only or
1092 write-only attributes), without the need to override __getattr__.
1093 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001094
Tim Petersbdee63f2001-09-02 03:40:59 +00001095- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001096 liberalized, to allow leading zeroes. Examples of literals now
1097 legal that were SyntaxErrors before:
1098
1099 00.0 0e3 0100j 07.5 00000000000000000008.
1100
Tim Petersbdee63f2001-09-02 03:40:59 +00001101- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001102 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1103
Tim Petersedc99312001-08-22 21:36:50 +00001104Library
1105
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001106- telnetlib includes symbolic names for the options, and support for
1107 setting an option negotiation callback.
1108
Tim Petersa40c7932001-09-05 22:36:56 +00001109- The new C standard no longer requires that math libraries set errno to
1110 ERANGE on overflow. For platform libraries that exploit this new
1111 freedom, Python's overflow-checking was wholly broken. A new overflow-
1112 checking scheme attempts to repair that, but may not be reliable on all
1113 platforms (C doesn't seem to provide anything both useful and portable
1114 in this area anymore).
1115
Martin v. Löwis44f86962001-09-05 13:44:54 +00001116- Asynchronous timeout actions are available through the new class
1117 threading.Timer.
1118
Tim Peters78526162001-09-05 00:53:45 +00001119- math.log and math.log10 now return sensible results for even huge
1120 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1121
Tim Petersbdee63f2001-09-02 03:40:59 +00001122- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001123 currently held. See the docs for the imp module.
1124
Tim Petersbdee63f2001-09-02 03:40:59 +00001125- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001126 dumps containing ints written on platforms where Python ints are 8 bytes.
1127 When read on a box where Python ints are 4 bytes, such values are
1128 converted to Python longs.
1129
Tim Petersbdee63f2001-09-02 03:40:59 +00001130- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001131 code objects is no longer allowed. This plugs a security hole.
1132
Steve Purcell6091cd62001-09-06 16:05:17 +00001133- unittest.TestResult instances no longer store references to tracebacks
1134 generated by test failures. This prevents unexpected dangling references
1135 to objects that should be garbage collected between tests.
1136
Tim Petersedc99312001-08-22 21:36:50 +00001137Tools
1138
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001139- Tools/scripts/fixdiv.py has been added which can be used to fix
1140 division operators as per PEP 238.
1141
Tim Petersedc99312001-08-22 21:36:50 +00001142Build
1143
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001144- If you are an adventurous person using Mac OS X you may want to look at
1145 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1146 application, which can be used for experimenting with Carbon or Cocoa.
1147 Discussion of this on pythonmac-sig, please.
1148
Tim Peters7eea37e2001-09-04 22:08:56 +00001149C API
1150
1151- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001152
Tim Peters9fffa3e2001-09-04 05:14:19 +00001153- Note that PyLong_AsDouble can fail! This has always been true, but no
1154 callers checked for it. It's more likely to fail now, because overflow
1155 errors are properly detected now. The proper way to check:
1156
1157 double x = PyLong_AsDouble(some_long_object);
1158 if (x == -1.0 && PyErr_Occurred()) {
1159 /* The conversion failed. */
1160 }
1161
Tim Petersbdee63f2001-09-02 03:40:59 +00001162- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001163 compile but will not participate in GC. To upgrade an extension
1164 module:
1165
1166 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001167
Neil Schemenauer4042c692001-08-30 15:38:01 +00001168 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1169 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001170
Neil Schemenauer4042c692001-08-30 15:38:01 +00001171 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1172 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001173
Neil Schemenauer4042c692001-08-30 15:38:01 +00001174 - remove PyGC_HEAD_SIZE from object size calculations
1175
1176 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1177
Tim Petersbdee63f2001-09-02 03:40:59 +00001178- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001179 These can be used safely to construct string objects from a
1180 sprintf-style format string (similar to the format string supported
1181 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001182
Tim Petersedc99312001-08-22 21:36:50 +00001183New platforms
1184
Tim Petersb7da0902001-09-02 23:01:43 +00001185- Stephen Hansen contributed patches sufficient to get a clean compile
1186 under Borland C (Windows), but he reports problems running it and ran
1187 out of time to complete the port. Volunteers? Expect a MemoryError
1188 when importing the types module; this is probably shallow, and
1189 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001190
Tim Petersedc99312001-08-22 21:36:50 +00001191Tests
1192
1193Windows
1194
Tim Peters6e13a562001-09-06 00:32:15 +00001195- Large file support is now enabled on Win32 platforms as well as on
1196 Win64. This means that, for example, you can use f.tell() and f.seek()
1197 to manipulate files larger than 2 gigabytes (provided you have enough
1198 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001199 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1200 filesize limit, and large file support makes no difference there.
1201 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1202 NTFS has no practical limit on file size, and files of any size can be
1203 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001204
Tim Petersbdee63f2001-09-02 03:40:59 +00001205- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001206 points to command.com (patch from Brian Quinlan).
1207
Tim Petersedc99312001-08-22 21:36:50 +00001208
Tim Peters20f51a72001-07-21 02:31:40 +00001209What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001210Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001211===========================
1212
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001213Build
1214
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001215- Tim Peters developed a brand new Windows installer using Wise 8.1,
1216 generously donated to us by Wise Solutions.
1217
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001218- configure supports a new option --enable-unicode, with the values
1219 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1220 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001221
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001222- A new configure option --enable-framework builds a Mac OS X framework,
1223 which "make frameworkinstall" will install. This provides a starting
1224 point for more mac-like functionality, join pythonmac-sig@python.org
1225 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001226
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001227- The NeXT platform is no longer supported.
1228
1229- The `new' module is now statically linked.
1230
Tim Peters0afb6092001-08-15 06:06:44 +00001231Tools
1232
1233- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001234 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001235 the module docstring for details.
1236
Tim Peters20f51a72001-07-21 02:31:40 +00001237Tests
1238
Tim Peters5e824c32001-08-12 22:25:01 +00001239- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001240 platforms, allowing to give clearer test result output. regrtest
1241 also has optional --use/-u switch to run normally disabled tests
1242 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001243
Tim Peters20f51a72001-07-21 02:31:40 +00001244- Several new tests in the standard test suite, with special thanks to
1245 Nick Mathewson.
1246
1247Core
1248
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001249- The floor division operator // has been added as outlined in PEP
1250 238. The / operator still provides classic division (and will until
1251 Python 3.0) unless "from __future__ import division" is included, in
1252 which case the / operator will provide true division. The operator
1253 module provides truediv() and floordiv() functions. Augmented
1254 assignment variants are included, as are the equivalent overloadable
1255 methods and C API methods. See the PEP for a full discussion:
1256 <http://python.sf.net/peps/pep-0238.html>
1257
Tim Peters6cd6a822001-08-17 22:11:27 +00001258- Future statements are now effective in simulated interactive shells
1259 (like IDLE). This should "just work" by magic, but read Michael
1260 Hudson's "Future statements in simulated shells" PEP 264 for full
1261 details: <http://python.sf.net/peps/pep-0264.html>.
1262
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001263- The type/class unification (PEP 252-253) was integrated into the
1264 trunk and is not so tentative any more (the exact specification of
1265 some features is still tentative). A lot of work has done on fixing
1266 bugs and adding robustness and features (performance still has to
1267 come a long way).
1268
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001269- Warnings about a mismatch in the Python API during extension import
1270 now use the Python warning framework (which makes it possible to
1271 write filters for these warnings).
1272
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001273- A function's __dict__ (aka func_dict) will now always be a
1274 dictionary. It used to be possible to delete it or set it to None,
1275 but now both actions raise TypeErrors. It is still legal to set it
1276 to a dictionary object. Getting func.__dict__ before any attributes
1277 have been assigned now returns an empty dictionary instead of None.
1278
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001279- A new command line option, -E, was added which disables the use of
1280 all environment variables, or at least those that are specifically
1281 significant to Python. Usually those have a name starting with
1282 "PYTHON". This was used to fix a problem where the tests fail if
1283 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1284 older distribution.
1285
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001286Library
1287
Tim Peters5e824c32001-08-12 22:25:01 +00001288- New class Differ and new functions ndiff() and restore() in difflib.py.
1289 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001290 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001291
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001292- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1293 value using the minimal quoting required for the value; more
1294 reliable than using xml.sax.saxutils.escape() for attribute values.
1295
1296- Readline completion support for cmd.Cmd was added.
1297
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001298- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1299
1300- Added function threading.BoundedSemaphore()
1301
1302- Added Ka-Ping Yee's cgitb.py module.
1303
1304- The `new' module now exposes the CO_xxx flags.
1305
Martin v. Löwis560da622001-11-24 09:24:51 +00001306- The gc module offers the get_referents function.
1307
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001308New platforms
1309
1310C API
1311
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001312- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1313 which provide a cross-platform implementations for the
1314 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1315 the standard sprintf() and vsprintf() C lib APIs, these versions
1316 apply bounds checking on the used buffer which enhances protection
1317 against buffer overruns.
1318
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001319- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001320 and extensions using different Unicode widths is rendered next to
1321 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001322 will result in an ImportError. Unicode extensions writers must make
1323 sure to check the Unicode width compatibility in their extensions by
1324 using at least one of the mangled Unicode APIs in the extension.
1325
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001326- Two new flags METH_NOARGS and METH_O are available in method definition
1327 tables to simplify implementation of methods with no arguments and a
1328 single untyped argument. Calling such methods is more efficient than
1329 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1330 deprecated.
1331
Tim Petersc1731372001-08-04 08:12:36 +00001332Windows
1333
1334- "import module" now compiles module.pyw if it exists and nothing else
1335 relevant is found.
1336
Tim Peters20f51a72001-07-21 02:31:40 +00001337
Guido van Rossum55a78992001-07-17 17:22:32 +00001338What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001339Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001340===========================
1341
1342Core
Tim Petersa814db52001-05-14 07:05:58 +00001343
Tim Peters6d6c1a32001-08-02 04:15:00 +00001344- TENTATIVELY, a large amount of code implementing much of what's
1345 described in PEP 252 (Making Types Look More Like Classes) and PEP
1346 253 (Subtyping Built-in Types) was added. This will be released
1347 with Python 2.2a1. Documentation will be provided separately
1348 through http://www.python.org/2.2/. The purpose of releasing this
1349 with Python 2.2a1 is to test backwards compatibility. It is
1350 possible, though not likely, that a decision is made not to release
1351 this code as part of 2.2 final, if any serious backwards
1352 incompapatibilities are found during alpha testing that cannot be
1353 repaired.
1354
Guido van Rossum55a78992001-07-17 17:22:32 +00001355- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001356 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001357 more 'yield' statements. See PEP 255. Since this adds a new
1358 keyword to the language, this feature must be enabled by including a
1359 future statement: "from __future__ import generators" (see PEP 236).
1360 Generators will become a standard feature in a future release
1361 (probably 2.3). Without this future statement, 'yield' remains an
1362 ordinary identifier, but a warning is issued each time it is used.
1363 (These warnings currently don't conform to the warnings framework of
1364 PEP 230; we intend to fix this in 2.2a2.)
1365
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001366- The UTF-16 codec was modified to be more RFC compliant. It will now
1367 only remove BOM characters at the start of the string and then
1368 only if running in native mode (UTF-16-LE and -BE won't remove a
1369 leading BMO character).
1370
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001371- Strings now have a new method .decode() to complement the already
1372 existing .encode() method. These two methods provide direct access
1373 to the corresponding decoders and encoders of the registered codecs.
1374
1375 To enhance the usability of the .encode() method, the special
1376 casing of Unicode object return values was dropped (Unicode objects
1377 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001378
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001379 Both methods will now return whatever the codec in charge of the
1380 requested encoding returns as object, e.g. Unicode codecs will
1381 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1382 will return u"äöü"). This enables codec writer to create codecs
1383 for various simple to use conversions.
1384
1385 New codecs were added to demonstrate these new features (the .encode()
1386 and .decode() columns indicate the type of the returned objects):
1387
1388 Name | .encode() | .decode() | Description
1389 ----------------------------------------------------------------------
1390 uu | string | string | UU codec (e.g. for email)
1391 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001392 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001393 zlib | string | string | zlib compression
1394 hex | string | string | 2-byte hex codec
1395 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1396
Mark Hammond2a0af792001-05-14 03:09:36 +00001397- Some operating systems now support the concept of a default Unicode
1398 encoding for file system operations. Notably, Windows supports 'mbcs'
1399 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001400 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001401 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001402
1403 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001404 functions that return filenames (such as os.listdir()) to return Python
1405 string objects pre-encoded using the default file system encoding for
1406 the platform. As this encoding is likely to be different from Python's
1407 default encoding, converting this name to a Unicode object before passing
1408 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001409 would attempt to use its default encoding (generally ASCII) rather than
1410 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001411
Tim Petersa814db52001-05-14 07:05:58 +00001412 In general, this change simply removes surprises when working with
1413 Unicode and the file system, making these operations work as you expect,
1414 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001415 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001416
Tim Peters61dff2b2001-05-08 15:43:37 +00001417- Float (and complex) literals in source code were evaluated to full
1418 precision only when running from a .py file; the same code loaded from a
1419 .pyc (or .pyo) file could suffer numeric differences starting at about the
1420 12th significant decimal digit. For example, on a machine with IEEE-754
1421 floating arithmetic,
1422
1423 x = 9007199254740992.0
1424 print long(x)
1425
1426 printed 9007199254740992 if run directly from .py, but 9007199254740000
1427 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1428 str(float) instead of repr(float) when building code objects. marshal
1429 now uses repr(float) instead, which should reproduce floats to full
1430 machine precision (assuming the platform C float<->string I/O conversion
1431 functions are of good quality).
1432
1433 This may cause floating-point results to change in some cases, and
1434 usually for the better, but may also cause numerically unstable
1435 algorithms to break.
1436
Tim Peters2f228e72001-05-13 00:19:31 +00001437- The implementation of dicts suffers fewer collisions, which has speed
1438 benefits. However, the order in which dict entries appear in dict.keys(),
1439 dict.values() and dict.items() may differ from previous releases for a
1440 given dict. Nothing is defined about this order, so no program should
1441 rely on it. Nevertheless, it's easy to write test cases that rely on the
1442 order by accident, typically because of printing the str() or repr() of a
1443 dict to an "expected results" file. See Lib/test/test_support.py's new
1444 sortdict(dict) function for a simple way to display a dict in sorted
1445 order.
1446
Tim Peters7a3bfc32001-06-12 01:22:22 +00001447- Many other small changes to dicts were made, resulting in faster
1448 operation along the most common code paths.
1449
Guido van Rossum10315822001-05-01 20:54:30 +00001450- Dictionary objects now support the "in" operator: "x in dict" means
1451 the same as dict.has_key(x).
1452
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001453- The update() method of dictionaries now accepts generic mapping
1454 objects. Specifically the argument object must support the .keys()
1455 and __getitem__() methods. This allows you to say, for example,
1456 {}.update(UserDict())
1457
Guido van Rossum10315822001-05-01 20:54:30 +00001458- Iterators were added; this is a generalized way of providing values
1459 to a for loop. See PEP 234. There's a new built-in function iter()
1460 to return an iterator. There's a new protocol to get the next value
1461 from an iterator using the next() method (in Python) or the
1462 tp_iternext slot (in C). There's a new protocol to get iterators
1463 using the __iter__() method (in Python) or the tp_iter slot (in C).
1464 Iterating (i.e. a for loop) over a dictionary generates its keys.
1465 Iterating over a file generates its lines.
1466
Tim Petersf553f892001-05-01 20:45:31 +00001467- The following functions were generalized to work nicely with iterator
1468 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001469 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001470 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1471 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001472 join() method of strings
1473 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001474 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1475 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001476 right-hand side of assignment statements with multiple targets, such as
1477 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001478
Tim Petersd85e1022001-05-11 21:51:48 +00001479- Accessing module attributes is significantly faster (for example,
1480 random.random or os.path or yourPythonModule.yourAttribute).
1481
Tim Peterse63415e2001-05-08 04:38:29 +00001482- Comparing dictionary objects via == and != is faster, and now works even
1483 if the keys and values don't support comparisons other than ==.
1484
Tim Peters95bf9392001-05-10 08:32:44 +00001485- Comparing dictionaries in ways other than == and != is slower: there were
1486 insecurities in the dict comparison implementation that could cause Python
1487 to crash if the element comparison routines for the dict keys and/or
1488 values mutated the dicts. Making the code bulletproof slowed it down.
1489
Tim Peterseb28ef22001-06-02 05:27:19 +00001490- Collisions in dicts are resolved via a new approach, which can help
1491 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001492 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001493 faster now. Thanks to Christian Tismer for pointing out the cause and
1494 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001495
Tim Peters52e155e2001-06-16 05:42:57 +00001496- repr() is much faster for large containers (dict, list, tuple).
1497
1498
Tim Petersa814db52001-05-14 07:05:58 +00001499Library
1500
Fred Drake960fdf92001-07-20 18:38:26 +00001501- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1502 were added to the string module. These a locale-indenpendent
1503 constants, unlike letters, lowercase, and uppercase. These are now
1504 use in appropriate locations in the standard library.
1505
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001506- The flags used in dlopen calls can now be configured using
1507 sys.setdlopenflags and queried using sys.getdlopenflags.
1508
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001509- Fredrik Lundh's xmlrpclib is now a standard library module. This
1510 provides full client-side XML-RPC support. In addition,
1511 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1512 one asyncore-based). Thanks to Eric Raymond for the documentation.
1513
Guido van Rossum643d3912001-07-05 14:46:25 +00001514- The xrange() object is simplified: it no longer supports slicing,
1515 repetition, comparisons, efficient 'in' checking, the tolist()
1516 method, or the start, stop and step attributes. See PEP 260.
1517
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001518- A new function fnmatch.filter to filter lists of file names was added.
1519
Barry Warsawffd674d2001-05-22 16:00:10 +00001520- calendar.py uses month and day names based on the current locale.
1521
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001522- strop is now *really* obsolete (this was announced before with 1.6),
1523 and issues DeprecationWarning when used (except for the four items
1524 that are still imported into string.py).
1525
Tim Petersa814db52001-05-14 07:05:58 +00001526- Cookie.py now sorts key+value pairs by key in output strings.
1527
1528- pprint.isrecursive(object) didn't correctly identify recursive objects.
1529 Now it does.
1530
Tim Peters95b3f782001-05-14 18:39:41 +00001531- pprint functions now much faster for large containers (tuple, list, dict).
1532
Tim Peters7b9542a2001-06-10 23:40:19 +00001533- New 'q' and 'Q' format codes in the struct module, corresponding to C
1534 types "long long" and "unsigned long long" (on Windows, __int64). In
1535 native mode, these can be used only when the platform C compiler supports
1536 these types (when HAVE_LONG_LONG is #define'd by the Python config
1537 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001538 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1539 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001540
Guido van Rossum83213cc2001-06-12 16:48:52 +00001541- The site module installs a new built-in function 'help' that invokes
1542 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1543 it displays a message reminding the user to use 'help()' or
1544 'help(object)'.
1545
Tim Petersa814db52001-05-14 07:05:58 +00001546Tests
1547
1548- New test_mutants.py runs dict comparisons where the key and value
1549 comparison operators mutute the dicts randomly during comparison. This
1550 rapidly causes Python to crash under earlier releases (not for the faint
1551 of heart: it can also cause Win9x to freeze or reboot!).
1552
1553- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001554 pprint.isreadable() return sensible results. Also verifies that simple
1555 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001556
Tim Peters4324aa32001-05-28 22:30:08 +00001557C API
1558
1559- Removed the unused last_is_sticky argument from the internal
1560 _PyTuple_Resize(). If this affects you, you were cheating.
1561
1562
Guido van Rossum55a78992001-07-17 17:22:32 +00001563======================================================================
1564
1565
Guido van Rossumffe13be2001-04-16 18:46:45 +00001566What's New in Python 2.1 (final)?
1567=================================
1568
1569We only changed a few things since the last release candidate, all in
1570Python library code:
1571
1572- A bug in the locale module was fixed that affected locales which
1573 define no grouping for numeric formatting.
1574
1575- A few bugs in the weakref module's implementations of weak
1576 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1577 and the test suite was updated to check for these bugs.
1578
1579- An old bug in the os.path.walk() function (introduced in Python
1580 2.0!) was fixed: a non-existent file would cause an exception
1581 instead of being ignored.
1582
1583- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1584 PyChecker.
1585
1586
Guido van Rossum5b08f132001-04-16 02:05:23 +00001587What's New in Python 2.1c2?
1588===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001589
Guido van Rossum5b08f132001-04-16 02:05:23 +00001590A flurry of small changes, and one showstopper fixed in the nick of
1591time made it necessary to release another release candidate. The list
1592here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001593
Guido van Rossum5b08f132001-04-16 02:05:23 +00001594Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001595
Guido van Rossum5b08f132001-04-16 02:05:23 +00001596- Tim discovered a nasty bug in the dictionary code, caused by
1597 PyDict_Next() calling dict_resize(), and the GC code's use of
1598 PyDict_Next() violating an assumption in dict_items(). This was
1599 fixed with considerable amounts of band-aid, but the net effect is a
1600 saner and more robust implementation.
1601
1602- Made a bunch of symbols static that were accidentally global.
1603
1604Build and Ports
1605
1606- The setup.py script didn't check for a new enough version of zlib
1607 (1.1.3 is needed). Now it does.
1608
1609- Changed "make clean" target to also remove shared libraries.
1610
1611- Added a more general warning about the SGI Irix optimizer to README.
1612
1613Library
1614
1615- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1616 omitted the slash between host and file.html.
1617
1618- The mailbox module's _Mailbox class contained a completely broken
1619 and undocumented seek() method. Ripped it out.
1620
1621- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1622 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1623
1624- Fixed a few last-minute bugs in unittest.
1625
1626Extensions
1627
1628- Reverted the patch to the OpenSSL code in socketmodule.c to support
1629 RAND_status() and the EGD, and the subsequent patch that tried to
1630 fix it for pre-0.9.5 versions; the problem with the patch is that on
1631 some systems it issues a warning whenever socket is imported, and
1632 that's unacceptable.
1633
1634Tests
1635
1636- Fixed the pickle tests to work with "import test.test_pickle".
1637
1638- Tweaked test_locale.py to actually run the test Windows.
1639
1640- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1641 not "wb" (which is not a valid mode at all).
1642
1643- Fix pstats browser crashes. Import readline if it exists to make
1644 the user interface nicer.
1645
1646- Add "import thread" to the top of test modules that import the
1647 threading module (test_asynchat and test_threadedtempfile). This
1648 prevents test failures caused by a broken threading module resulting
1649 from a previously caught failed import.
1650
1651- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1652 needed on some platforms (e.g. Solaris 8) when the tests are run
1653 twice in succession.
1654
1655- Skip rather than fail test_sunaudiodev if no audio device is found.
1656
1657
1658What's New in Python 2.1c1?
1659===========================
1660
1661This list was significantly updated when 2.1c2 was released; the 2.1c1
1662release didn't mention most changes that were actually part of 2.1c1:
1663
1664Legal
1665
1666- Copyright was assigned to the Python Software Foundation (PSF) and a
1667 PSF license (very similar to the CNRI license) was added.
1668
1669- The CNRI copyright notice was updated to include 2001.
1670
1671Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001672
Guido van Rossumc9932722001-04-12 02:31:27 +00001673- After a public outcry, assignment to __debug__ is no longer illegal;
1674 instead, a warning is issued. It will become illegal in 2.2.
1675
Guido van Rossum5b08f132001-04-16 02:05:23 +00001676- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1677 "%#x" now always prepends "0x", even if the value is zero.
1678
1679- Fixed some nits in the bytecode compiler.
1680
1681- Fixed core dumps when calling certain kinds of non-functions.
1682
1683- Fixed various core dumps caused by reference count bugs.
1684
1685Build and Ports
1686
1687- Use INSTALL_SCRIPT to install script files.
1688
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001689- New port: SCO Unixware 7, by Billy G. Allie.
1690
Guido van Rossum5b08f132001-04-16 02:05:23 +00001691- Updated RISCOS port.
1692
1693- Updated BeOS port and notes.
1694
1695- Various other porting problems resolved.
1696
1697Library
1698
1699- The TERMIOS and SOCKET modules are now truly obsolete and
1700 unnecessary. Their symbols are incorporated in the termios and
1701 socket modules.
1702
1703- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1704 better tests for pickling.
1705
1706- threading: make Condition.wait() robust against KeyboardInterrupt.
1707
1708- zipfile: add support to zipfile to support opening an archive
1709 represented by an open file rather than a file name. Fix bug where
1710 the archive was not properly closed. Fixed a bug in this bugfix
1711 where flush() was called for a read-only file.
1712
1713- imputil: added an uninstall() method to the ImportManager.
1714
1715- Canvas: fixed bugs in lower() and tkraise() methods.
1716
1717- SocketServer: API change (added overridable close_request() method)
1718 so that the TCP server can explicitly close the request.
1719
1720- pstats: Eric Raymond added a simple interactive statistics browser,
1721 invoked when the module is run as a script.
1722
1723- locale: fixed a problem in format().
1724
1725- webbrowser: made it work when the BROWSER environment variable has a
1726 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1727 KDE 2. Fixed some other nits.
1728
1729- unittest: changes to allow using a different exception than
1730 AssertionError, and added a few more function aliases. Some other
1731 small changes.
1732
1733- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1734
1735- asynchat: fixed a critical bug in asynchat that slipped through the
1736 2.1b2 release. Fixed another rare bug.
1737
1738- Fix some unqualified except: clauses (always a bad code example).
1739
1740XML
1741
1742- pyexpat: new API get_version_string().
1743
1744- Fixed some minidom bugs.
1745
1746Extensions
1747
1748- Fixed a core dump in _weakref. Removed the weakref.mapping()
1749 function (it adds nothing to the API).
1750
1751- Rationalized the use of header files in the readline module, to make
1752 it compile (albeit with some warnings) with the very recent readline
1753 4.2, without breaking for earlier versions.
1754
1755- Hopefully fixed a buffering problem in linuxaudiodev.
1756
1757- Attempted a fix to make the OpenSSL support in the socket module
1758 work again with pre-0.9.5 versions of OpenSSL.
1759
1760Tests
1761
1762- Added a test case for asynchat and asyncore.
1763
1764- Removed coupling between tests where one test failing could break
1765 another.
1766
1767Tools
1768
1769- Ping added an interactive help browser to pydoc, fixed some nits
1770 in the rest of the pydoc code, and added some features to his
1771 inspect module.
1772
1773- An updated python-mode.el version 4.1 which integrates Ken
1774 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1775 much nicer in XEmacs and Emacs. When stepping through your program
1776 with pdb, in either the shell window or the *Python* window, the
1777 source file and line will be tracked by an arrow. Very cool!
1778
1779- IDLE: syntax warnings in interactive mode are changed into errors.
1780
1781- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001782 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001783
1784- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001785
Barry Warsaw11e89c72001-04-11 20:37:57 +00001786
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001787What's New in Python 2.1 beta 2?
1788================================
1789
Guido van Rossum053ae352001-03-22 14:17:21 +00001790(Unlisted are many fixed bugs, more documentation, etc.)
1791
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001792Core language, builtins, and interpreter
1793
Guido van Rossum053ae352001-03-22 14:17:21 +00001794- The nested scopes work (enabled by "from __future__ import
1795 nested_scopes") is completed; in particular, the future now extends
1796 into code executed through exec, eval() and execfile(), and into the
1797 interactive interpreter.
1798
1799- When calling a base class method (e.g. BaseClass.__init__(self)),
1800 this is now allowed even if self is not strictly spoken a class
1801 instance (e.g. when using metaclasses or the Don Beaudry hook).
1802
1803- Slice objects are now comparable but not hashable; this prevents
1804 dict[:] from being accepted but meaningless.
1805
1806- Complex division is now calculated using less braindead algorithms.
1807 This doesn't change semantics except it's more likely to give useful
1808 results in extreme cases. Complex repr() now uses full precision
1809 like float repr().
1810
1811- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1812
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001813- It is illegal to assign to the name __debug__, which is set when the
1814 interpreter starts. It is effectively a compile-time constant.
1815
1816- A warning will be issued if a global statement for a variable
1817 follows a use or assignment of that variable.
1818
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001819Standard library
1820
Guido van Rossum053ae352001-03-22 14:17:21 +00001821- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1822 inspired by JUnit), is now part of the standard library. You now
1823 have a choice of two testing frameworks: unittest requires you to
1824 write testcases as separate code, doctest gathers them from
1825 docstrings. Both approaches have their advantages and
1826 disadvantages.
1827
1828- A new module Tix was added, which wraps the Tix extension library
1829 for Tk. With that module, it is not necessary to statically link
1830 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1831 require" command. See Demo/tix/.
1832
1833- tzparse.py is now obsolete.
1834
1835- In gzip.py, the seek() and tell() methods are removed -- they were
1836 non-functional anyway, and it's better if callers can test for their
1837 existence with hasattr().
1838
1839Python/C API
1840
1841- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1842 that's already in the dictionary during a PyDict_Next() iteration.
1843 This used to fail occasionally when a dictionary resize operation
1844 could be triggered that would rehash all the keys. All other
1845 modifications to the dictionary are still off-limits during a
1846 PyDict_Next() iteration!
1847
1848- New extended APIs related to passing compiler variables around.
1849
1850- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1851 implement isinstance() and issubclass().
1852
1853- Py_BuildValue() now has a "D" conversion to create a Python complex
1854 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001855
Fred Drake4e262a92001-03-22 18:26:47 +00001856- Extensions types which support weak references must now set the
1857 field allocated for the weak reference machinery to NULL themselves;
1858 this is done to avoid the cost of checking each object for having a
1859 weakly referencable type in PyObject_INIT(), since most types are
1860 not weakly referencable.
1861
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001862- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1863 free variables and cell variables to and from the frame's f_locals.
1864
1865- Variants of several functions defined in pythonrun.h have been added
1866 to support the nested_scopes future statement. The variants all end
1867 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1868 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1869 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001870 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001871
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001872Distutils
1873
1874- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1875 into the release tree.
1876
Tim Peters0e57abf2001-05-02 07:39:38 +00001877- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001878 (an uninstaller, more customization of the installer's display)
1879
1880- from Jack Jansen: added Mac-specific code to generate a dialog for
1881 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001882 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001883 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001884
1885- added 'platforms' and 'keywords' to the set of metadata that can be
1886 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001887
1888- applied patches from Jason Tishler to make the compiler class work with
1889 Cygwin.
1890
1891
Tim Peters2fe289a2001-03-01 22:19:38 +00001892What's New in Python 2.1 beta 1?
1893================================
Tim Petersd66595f2001-02-04 03:09:53 +00001894
1895Core language, builtins, and interpreter
1896
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001897- Following an outcry from the community about the amount of code
1898 broken by the nested scopes feature introduced in 2.1a2, we decided
1899 to make this feature optional, and to wait until Python 2.2 (or at
1900 least 6 months) to make it standard. The option can be enabled on a
1901 per-module basis by adding "from __future__ import nested_scopes" at
1902 the beginning of a module (before any other statements, but after
1903 comments and an optional docstring). See PEP 236 (Back to the
1904 __future__) for a description of the __future__ statement. PEP 227
1905 (Statically Nested Scopes) has been updated to reflect this change,
1906 and to clarify the semantics in a number of endcases.
1907
1908- The nested scopes code, when enabled, has been hardened, and most
1909 bugs and memory leaks in it have been fixed.
1910
1911- Compile-time warnings are now generated for a number of conditions
1912 that will break or change in meaning when nested scopes are enabled:
1913
1914 - Using "from...import *" or "exec" without in-clause in a function
1915 scope that also defines a lambda or nested function with one or
1916 more free (non-local) variables. The presence of the import* or
1917 bare exec makes it impossible for the compiler to determine the
1918 exact set of local variables in the outer scope, which makes it
1919 impossible to determine the bindings for free variables in the
1920 inner scope. To avoid the warning about import *, change it into
1921 an import of explicitly name object, or move the import* statement
1922 to the global scope; to avoid the warning about bare exec, use
1923 exec...in... (a good idea anyway -- there's a possibility that
1924 bare exec will be deprecated in the future).
1925
1926 - Use of a global variable in a nested scope with the same name as a
1927 local variable in a surrounding scope. This will change in
1928 meaning with nested scopes: the name in the inner scope will
1929 reference the variable in the outer scope rather than the global
1930 of the same name. To avoid the warning, either rename the outer
1931 variable, or use a global statement in the inner function.
1932
Neil Schemenauera35c6882001-02-27 04:45:05 +00001933- An optional object allocator has been included. This allocator is
1934 optimized for Python objects and should be faster and use less memory
1935 than the standard system allocator. It is not enabled by default
1936 because of possible thread safety problems. The allocator is only
1937 protected by the Python interpreter lock and it is possible that some
1938 extension modules require a thread safe allocator. The object
1939 allocator can be enabled by providing the "--with-pymalloc" option to
1940 configure.
1941
Tim Petersd66595f2001-02-04 03:09:53 +00001942Standard library
1943
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001944- pyexpat now detects the expat version if expat.h defines it. A
1945 number of additional handlers are provided, which are only available
1946 since expat 1.95. In addition, the methods SetParamEntityParsing and
1947 GetInputContext of Parser objects are available with 1.95.x
1948 only. Parser objects now provide the ordered_attributes and
1949 specified_attributes attributes. A new module expat.model was added,
1950 which offers a number of additional constants if 1.95.x is used.
1951
1952- xml.dom offers the new functions registerDOMImplementation and
1953 getDOMImplementation.
1954
1955- xml.dom.minidom offers a toprettyxml method. A number of DOM
1956 conformance issues have been resolved. In particular, Element now
1957 has an hasAttributes method, and the handling of namespaces was
1958 improved.
1959
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001960- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1961 getting information about live Python code, and pydoc.py, a module
1962 for interactively converting docstrings to HTML or text.
1963 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001964 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001965 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1966 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001967
Tim Peters1eff7962001-03-01 02:31:33 +00001968- New library module difflib.py, primarily packaging the SequenceMatcher
1969 class at the heart of the popular ndiff.py file-comparison tool.
1970
1971- doctest.py (a framework for verifying Python code examples in docstrings)
1972 is now part of the std library.
1973
Tim Petersd66595f2001-02-04 03:09:53 +00001974Windows changes
1975
Guido van Rossume3955a82001-03-02 14:05:59 +00001976- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1977 small GUI that lets you browse the module docstrings using your
1978 default web browser.
1979
Tim Peters1eff7962001-03-01 02:31:33 +00001980- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1981 Platforms) is implemented. See
1982
1983 http://python.sourceforge.net/peps/pep-0235.html
1984
1985 for full details, especially the "Current Lower-Left Semantics" section.
1986 The new Windows import rules are simpler than before:
1987
1988 A. If the PYTHONCASEOK environment variable exists, same as
1989 before: silently accept the first case-insensitive match of any
1990 kind; raise ImportError if none found.
1991
1992 B. Else search sys.path for the first case-sensitive match; raise
1993 ImportError if none found.
1994
1995 The same rules have been implented on other platforms with case-
1996 insensitive but case-preserving filesystems too (including Cygwin, and
1997 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001998
Tim Peters25a9ce32001-02-19 07:06:36 +00001999- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
2000 what it's supposed to do (and does do under NT and 2000) via direct
2001 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00002002 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00002003 all Win9x systems before.
2004
Tim Peters1eff7962001-03-01 02:31:33 +00002005- Build: Subproject _test (effectively) renamed to _testcapi.
2006
Tim Peters2fe289a2001-03-01 22:19:38 +00002007New platforms
2008
2009- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2010 Thanks to Steven Majewski!
2011
2012- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2013 Tishler!
2014
Guido van Rossum9089b272001-03-02 06:49:50 +00002015- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2016 Schwertberger! See RISCOS/README for more information -- it seems
2017 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002018 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002019
Tim Peters25a9ce32001-02-19 07:06:36 +00002020
Tim Petersd7b5e882001-01-25 03:36:26 +00002021What's New in Python 2.1 alpha 2?
2022=================================
Tim Peters40ead762001-01-27 05:35:26 +00002023
Tim Petersd7b5e882001-01-25 03:36:26 +00002024Core language, builtins, and interpreter
2025
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002026- Scopes nest. If a name is used in a function or class, but is not
2027 local, the definition in the nearest enclosing function scope will
2028 be used. One consequence of this change is that lambda statements
2029 could reference variables in the namespaces where the lambda is
2030 defined. In some unusual cases, this change will break code.
2031
2032 In all previous version of Python, names were resolved in exactly
2033 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002034 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002035 function A is defined within a function B, the names bound in B are
2036 not visible in A. The new rules make names bound in B visible in A,
2037 unless A contains a name binding that hides the binding in B.
2038
2039 Section 4.1 of the reference manual describes the new scoping rules
2040 in detail. The test script in Lib/test/test_scope.py demonstrates
2041 some of the effects of the change.
2042
2043 The new rules will cause existing code to break if it defines nested
2044 functions where an outer function has local variables with the same
2045 name as globals or builtins used by the inner function. Example:
2046
2047 def munge(str):
2048 def helper(x):
2049 return str(x)
2050 if type(str) != type(''):
2051 str = helper(str)
2052 return str.strip()
2053
2054 Under the old rules, the name str in helper() is bound to the
2055 builtin function str(). Under the new rules, it will be bound to
2056 the argument named str and an error will occur when helper() is
2057 called.
2058
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002059- The compiler will report a SyntaxError if "from ... import *" occurs
2060 in a function or class scope. The language reference has documented
2061 that this case is illegal, but the compiler never checked for it.
2062 The recent introduction of nested scope makes the meaning of this
2063 form of name binding ambiguous. In a future release, the compiler
2064 may allow this form when there is no possibility of ambiguity.
2065
Tim Peters40ead762001-01-27 05:35:26 +00002066- repr(string) is easier to read, now using hex escapes instead of octal,
2067 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2068
2069 >>> "\texample \r\n" + chr(0) + chr(255)
2070 '\texample \r\n\x00\xff' # in 2.1
2071 '\011example \015\012\000\377' # in 2.0
2072
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002073- Functions are now compared and hashed by identity, not by value, since
2074 the func_code attribute is writable.
2075
Fred Drakefb9d7122001-02-01 20:00:40 +00002076- Weak references (PEP 205) have been added. This involves a few
2077 changes in the core, an extension module (_weakref), and a Python
2078 module (weakref). The weakref module is the public interface. It
2079 includes support for "explicit" weak references, proxy objects, and
2080 mappings with weakly held values.
2081
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002082- A 'continue' statement can now appear in a try block within the body
2083 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002084 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002085
Tim Petersd7b5e882001-01-25 03:36:26 +00002086Standard library
2087
Barry Warsaw30dbd142001-01-31 22:14:01 +00002088- mailbox.py now has a new class, PortableUnixMailbox which is
2089 identical to UnixMailbox but uses a more portable scheme for
2090 determining From_ separators. Also, the constructors for all the
2091 classes in this module have a new optional `factory' argument, which
2092 is a callable used when new message classes must be instantiated by
2093 the next() method.
2094
Tim Petersd7b5e882001-01-25 03:36:26 +00002095- random.py is now self-contained, and offers all the functionality of
2096 the now-deprecated whrandom.py. See the docs for details. random.py
2097 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002098 and restoring the internal state of the generator; and jumpahead(n),
2099 for quickly forcing the internal state to be the same as if n calls to
2100 random() had been made. The latter is particularly useful for multi-
2101 threaded programs, creating one instance of the random.Random() class for
2102 each thread, then using .jumpahead() to force each instance to use a
2103 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002104
Tim Peters0de88fc2001-02-01 04:59:18 +00002105- random.py's seed() function is new. For bit-for-bit compatibility with
2106 prior releases, use the whseed function instead. The new seed function
2107 addresses two problems: (1) The old function couldn't produce more than
2108 about 2**24 distinct internal states; the new one about 2**45 (the best
2109 that can be done in the Wichmann-Hill generator). (2) The old function
2110 sometimes produced identical internal states when passed distinct
2111 integers, and there was no simple way to predict when that would happen;
2112 the new one guarantees to produce distinct internal states for all
2113 arguments in [0, 27814431486576L).
2114
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002115- The socket module now supports raw packets on Linux. The socket
2116 family is AF_PACKET.
2117
Tim Peters9ea17ac2001-02-02 05:57:15 +00002118- test_capi.py is a start at running tests of the Python C API. The tests
2119 are implemented by the new Modules/_testmodule.c.
2120
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002121- A new extension module, _symtable, provides provisional access to the
2122 internal symbol table used by the Python compiler. A higher-level
2123 interface will be added on top of _symtable in a future release.
2124
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002125- Removed the obsolete soundex module.
2126
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002127- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2128 the isSameNode method; NamedNodeMap the get method.
2129
2130- xml.sax.expatreader supports the lexical handler property; it
2131 generates comment, startCDATA, and endCDATA events.
2132
Tim Petersee826f82001-01-31 19:39:44 +00002133Windows changes
2134
2135- Build procedure: the zlib project is built in a different way that
2136 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002137 the zlib binary used. See PCbuild\readme.txt for details. Your old
2138 zlib-related directories can be deleted; you'll need to download fresh
2139 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002140
Tim Peters9ea17ac2001-02-02 05:57:15 +00002141- Build: New subproject _test for the benefit of test_capi.py (see above).
2142
Tim Petersb16c56f2001-02-02 21:24:51 +00002143- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2144 interface to some Python compiler internals).
2145
2146- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002147 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002148
Tim Petersa3a3a032000-11-30 05:22:44 +00002149What's New in Python 2.1 alpha 1?
2150=================================
2151
2152Core language, builtins, and interpreter
2153
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002154- There is a new Unicode companion to the PyObject_Str() API
2155 called PyObject_Unicode(). It behaves in the same way as the
2156 former, but assures that the returned value is an Unicode object
2157 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002158
Guido van Rossumf98eda02001-01-17 15:54:45 +00002159- The comparison operators support "rich comparison overloading" (PEP
2160 207). C extension types can provide a rich comparison function in
2161 the new tp_richcompare slot in the type object. The cmp() function
2162 and the C function PyObject_Compare() first try the new rich
2163 comparison operators before trying the old 3-way comparison. There
2164 is also a new C API PyObject_RichCompare() (which also falls back on
2165 the old 3-way comparison, but does not constrain the outcome of the
2166 rich comparison to a Boolean result).
2167
2168 The rich comparison function takes two objects (at least one of
2169 which is guaranteed to have the type that provided the function) and
2170 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2171 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2172 object, which may be NotImplemented (in which case the tp_compare
2173 slot function is used as a fallback, if defined).
2174
2175 Classes can overload individual comparison operators by defining one
2176 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002177 __ge__. There are no explicit "reflected argument" versions of
2178 these; instead, __lt__ and __gt__ are each other's reflection,
2179 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2180 reflection (similar at the C level). No other implications are
2181 made; in particular, Python does not assume that == is the Boolean
2182 inverse of !=, or that < is the Boolean inverse of >=. This makes
2183 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002184
2185 Classes or types that want to implement (in)equality tests but not
2186 the ordering operators (i.e. unordered types) should implement ==
2187 and !=, and raise an error for the ordering operators.
2188
Guido van Rossuma88479f2001-01-18 14:28:08 +00002189 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002190 Boolean; e.g. a matrix type might want to return a matrix of bits
2191 for A < B, giving elementwise comparisons. Such types should ensure
2192 that any interpretation of their value in a Boolean context raises
2193 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2194 at the C level) to always raise an exception.
2195
Guido van Rossuma88479f2001-01-18 14:28:08 +00002196- Complex numbers use rich comparisons to define == and != but raise
2197 an exception for <, <=, > and >=. Unfortunately, this also means
2198 that cmp() of two complex numbers raises an exception when the two
2199 numbers differ. Since it is not mathematically meaningful to compare
2200 complex numbers except for equality, I hope that this doesn't break
2201 too much code.
2202
Tim Peters3389f192001-02-18 08:48:49 +00002203- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002204 not defined by the language, other than that it's arbitrary but
2205 consistent (see the Reference Manual). An implementation detail changed
2206 in 2.1a1 such that None now compares less than any other object. Code
2207 relying on this new behavior (like code that relied on the previous
2208 behavior) does so at its own risk.
2209
Barry Warsaw573b5412001-01-15 20:43:18 +00002210- Functions and methods now support getting and setting arbitrarily
2211 named attributes (PEP 232). Functions have a new __dict__
2212 (a.k.a. func_dict) which hold the function attributes. Methods get
2213 and set attributes on their underlying im_func. It is a TypeError
2214 to set an attribute on a bound method.
2215
Guido van Rossum051e3352001-01-15 19:11:10 +00002216- The xrange() object implementation has been improved so that
2217 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2218 limitation that in this case len(xrange(sys.maxint)) can't be
2219 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2220 work fine as long as the index i doesn't actually reach 2**31.
2221 (Python uses regular ints for sequence and string indices; fixing
2222 that is much more work.)
2223
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002224- Two changes to from...import:
2225
Guido van Rossumba381232001-02-03 15:06:40 +00002226 1) "from M import X" now works even if (after loading module M)
2227 sys.modules['M'] is not a real module; it's basically a getattr()
2228 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002229
2230 2) "from M import *" now looks for M.__all__ to decide which names to
2231 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2232 filters out names starting with '_' as before. Whether or not
2233 __all__ exists, there's no restriction on the type of M.
2234
Guido van Rossumf61f1662001-01-10 20:13:55 +00002235- File objects have a new method, xreadlines(). This is the fastest
2236 way to iterate over all lines in a file:
2237
2238 for line in file.xreadlines():
2239 ...do something to line...
2240
2241 See the xreadlines module (mentioned below) for how to do this for
2242 other file-like objects.
2243
2244- Even if you don't use file.xreadlines(), you may expect a speedup on
2245 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002246 quite a bit in platform-specific ways: on systems (like Linux) that
2247 support flockfile(), getc_unlocked(), and funlockfile(), those are
2248 used by default. On systems (like Windows) without getc_unlocked(),
2249 a complicated (but still thread-safe) method using fgets() is used by
2250 default.
2251
Tim Petersd52269b2001-01-25 06:23:18 +00002252 You can force use of the fgets() method by #define'ing
2253 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002254 getc_unlocked()).
2255
Tim Petersd52269b2001-01-25 06:23:18 +00002256 You can force fgets() not to be used by #define'ing
2257 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002258 test_bufio.py fails -- and let us know if it does!).
2259
2260- In addition, the fileinput module, while still slower than the other
2261 methods on most platforms, has been sped up too, by using
2262 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002263
2264- Support for run-time warnings has been added, including a new
2265 command line option (-W) to specify the disposition of warnings.
2266 See the description of the warnings module below.
2267
2268- Extensive changes have been made to the coercion code. This mostly
2269 affects extension modules (which can now implement mixed-type
2270 numerical operators without having to use coercion), but
2271 occasionally, in boundary cases the coercion semantics have changed
2272 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002273 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002274 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002275 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002276
Guido van Rossumf98eda02001-01-17 15:54:45 +00002277- In connection with the coercion changes, a new built-in singleton
2278 object, NotImplemented is defined. This can be returned for
2279 operations that wish to indicate they are not implemented for a
2280 particular combination of arguments. From C, this is
2281 Py_NotImplemented.
2282
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002283- The interpreter accepts now bytecode files on the command line even
2284 if they do not have a .pyc or .pyo extension. On Linux, after executing
2285
Martin v. Löwise214baa2001-02-04 22:37:56 +00002286import imp,sys,string
2287magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2288reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2289open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002290
2291 any byte code file can be used as an executable (i.e. as an argument
2292 to execve(2)).
2293
Tim Peters9940b802000-12-01 07:59:35 +00002294- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002295 character. In 1.6 and earlier, they never produced a sign,
2296 and raised an error if the value of the long was too large
2297 to fit in a Python int. In 2.0, they produced a sign if and
2298 only if too large to fit in an int. This was inconsistent
2299 across platforms (because the size of an int varies across
2300 platforms), and inconsistent with hex() and oct(). Example:
2301
2302 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002303 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002304 'ffffffbe' # in 2.0 and before, on 32-bit machines
2305 >>> hex(-0x42L)
2306 '-0x42L' # in all versions of Python
2307
Tim Peters9940b802000-12-01 07:59:35 +00002308 The behavior of %d formats for negative Python longs remains
2309 the same as in 2.0 (although in 1.6 and before, they raised
2310 an error if the long didn't fit in a Python int).
2311
2312 %u formats don't make sense for Python longs, but are allowed
2313 and treated the same as %d in 2.1. In 2.0, a negative long
2314 formatted via %u produced a sign if and only if too large to
2315 fit in an int. In 1.6 and earlier, a negative long formatted
2316 via %u raised an error if it was too big to fit in an int.
2317
Guido van Rossum3661d392000-12-12 22:10:31 +00002318- Dictionary objects have an odd new method, popitem(). This removes
2319 an arbitrary item from the dictionary and returns it (in the form of
2320 a (key, value) pair). This can be useful for algorithms that use a
2321 dictionary as a bag of "to do" items and repeatedly need to pick one
2322 item. Such algorithms normally end up running in quadratic time;
2323 using popitem() they can usually be made to run in linear time.
2324
Tim Peters36cdad12000-12-29 02:06:45 +00002325Standard library
2326
Thomas Woutersfe385252001-01-19 23:16:56 +00002327- In the time module, the time argument to the functions strftime,
2328 localtime, gmtime, asctime and ctime is now optional, defaulting to
2329 the current time (in the local timezone).
2330
Guido van Rossumda91f222001-01-15 16:36:08 +00002331- The ftplib module now defaults to passive mode, which is deemed a
2332 more useful default given that clients are often inside firewalls
2333 these days. Note that this could break if ftplib is used to connect
2334 to a *server* that is inside a firewall, from outside; this is
2335 expected to be a very rare situation. To fix that, you can call
2336 ftp.set_pasv(0).
2337
Martin v. Löwis10a27872001-01-13 09:54:41 +00002338- The module site now treats .pth files not only for path configuration,
2339 but also supports extensions to the initialization code: Lines starting
2340 with import are executed.
2341
Guido van Rossumf61f1662001-01-10 20:13:55 +00002342- There's a new module, warnings, which implements a mechanism for
2343 issuing and filtering warnings. There are some new built-in
2344 exceptions that serve as warning categories, and a new command line
2345 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2346 turns warnings into errors). warnings.warn(message[, category])
2347 issues a warning message; this can also be called from C as
2348 PyErr_Warn(category, message).
2349
2350- A new module xreadlines was added. This exports a single factory
2351 function, xreadlines(). The intention is that this code is the
2352 absolutely fastest way to iterate over all lines in an open
2353 file(-like) object:
2354
2355 import xreadlines
2356 for line in xreadlines.xreadlines(file):
2357 ...do something to line...
2358
2359 This is equivalent to the previous the speed record holder using
2360 file.readlines(sizehint). Note that if file is a real file object
2361 (as opposed to a file-like object), this is equivalent:
2362
2363 for line in file.xreadlines():
2364 ...do something to line...
2365
Tim Peters36cdad12000-12-29 02:06:45 +00002366- The bisect module has new functions bisect_left, insort_left,
2367 bisect_right and insort_right. The old names bisect and insort
2368 are now aliases for bisect_right and insort_right. XXX_right
2369 and XXX_left methods differ in what happens when the new element
2370 compares equal to one or more elements already in the list: the
2371 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002372 right. Code that doesn't care where equal elements end up should
2373 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002374
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002375- The new curses.panel module wraps the panel library that forms part
2376 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2377
Guido van Rossumf61f1662001-01-10 20:13:55 +00002378- The SocketServer module now sets the allow_reuse_address flag by
2379 default in the TCPServer class.
2380
2381- A new function, sys._getframe(), returns the stack frame pointer of
2382 the caller. This is intended only as a building block for
2383 higher-level mechanisms such as string interpolation.
2384
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002385- The pyexpat module supports a number of new handlers, which are
2386 available only in expat 1.2. If invocation of a callback fails, it
2387 will report an additional frame in the traceback. Parser objects
2388 participate now in garbage collection. If expat reports an unknown
2389 encoding, pyexpat will try to use a Python codec; that works only
2390 for single-byte charsets. The parser type objects is exposed as
2391 XMLParserObject.
2392
2393- xml.dom now offers standard definitions for symbolic node type and
2394 exception code constants, and a hierarchy of DOM exceptions. minidom
2395 was adjusted to use them.
2396
2397- The conformance of xml.dom.minidom to the DOM specification was
2398 improved. It detects a number of additional error cases; the
2399 previous/next relationship works even when the tree is modified;
2400 Node supports the normalize() method; NamedNodeMap, DocumentType and
2401 DOMImplementation classes were added; Element supports the
2402 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2403 method.
2404
Guido van Rossumf61f1662001-01-10 20:13:55 +00002405Build issues
2406
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002407- For Unix (and Unix-compatible) builds, configuration and building of
2408 extension modules is now greatly automated. Rather than having to
2409 edit the Modules/Setup file to indicate which modules should be
2410 built and where their include files and libraries are, a
2411 distutils-based setup.py script now takes care of building most
2412 extension modules. All extension modules built this way are built
2413 as shared libraries. Only a few modules that must be linked
2414 statically are still listed in the Setup file; you won't need to
2415 edit their configuration.
2416
2417- Python should now build out of the box on Cygwin. If it doesn't,
2418 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002419
2420- Python now always uses its own (renamed) implementation of getopt()
2421 -- there's too much variation among C library getopt()
2422 implementations.
2423
2424- C++ compilers are better supported; the CXX macro is always set to a
2425 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002426
Tim Petersd92dfe02000-12-12 01:18:41 +00002427Windows changes
2428
2429- select module: By default under Windows, a select() call
2430 can specify no more than 64 sockets. Python now boosts
2431 this Microsoft default to 512. If you need even more than
2432 that, see the MS docs (you'll need to #define FD_SETSIZE
2433 and recompile Python from source).
2434
Guido van Rossumf61f1662001-01-10 20:13:55 +00002435- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2436 subdirectory is no more!
2437
Tim Petersa3a3a032000-11-30 05:22:44 +00002438
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002439What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002440=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002441
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002442Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002443changes are in the file HISTORY. If you are making the jump directly
2444from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2445HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002446
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002447Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2448the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2449http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002450
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002451--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002452
2453======================================================================
2454
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002455What's new in 2.0 (since release candidate 1)?
2456==============================================
2457
2458Standard library
2459
2460- The copy_reg module was modified to clarify its intended use: to
2461 register pickle support for extension types, not for classes.
2462 pickle() will raise a TypeError if it is passed a class.
2463
2464- Fixed a bug in gettext's "normalize and expand" code that prevented
2465 it from finding an existing .mo file.
2466
2467- Restored support for HTTP/0.9 servers in httplib.
2468
Tim Peters989b7b92000-10-16 20:24:53 +00002469- The math module was changed to stop raising OverflowError in case of
2470 underflow, and return 0 instead in underflow cases. Whether Python
2471 used to raise OverflowError in case of underflow was platform-
2472 dependent (it did when the platform math library set errno to ERANGE
2473 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002474
2475- Fixed a bug in StringIO that occurred when the file position was not
2476 at the end of the file and write() was called with enough data to
2477 extend past the end of the file.
2478
2479- Fixed a bug that caused Tkinter error messages to get lost on
2480 Windows. The bug was fixed by replacing direct use of
2481 interp->result with Tcl_GetStringResult(interp).
2482
2483- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2484 redirect response.
2485
2486- Several changes were made to distutils: Some debugging code was
2487 removed from util. Fixed the installer used when an external zip
2488 program (like WinZip) is not found; the source code for this
2489 installer is in Misc/distutils. check_lib() was modified to behave
2490 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2491 test for whether installed modules are on sys.path was changed to
2492 use both normcase() and normpath().
2493
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002494- Several minor bugs were fixed in the xml package (the minidom,
2495 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002496
2497- The regression test driver (regrtest.py) behavior when invoked with
2498 -l changed: It now reports a count of objects that are recognized as
2499 garbage but not freed by the garbage collector.
2500
Tim Peters989b7b92000-10-16 20:24:53 +00002501- The regression test for the math module was changed to test
2502 exceptional behavior when the test is run in verbose mode. Python
2503 cannot yet guarantee consistent exception behavior across platforms,
2504 so the exception part of test_math is run only in verbose mode, and
2505 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002506
2507Internals
2508
2509- PyOS_CheckStack() has been disabled on Win64, where it caused
2510 test_sre to fail.
2511
2512Build issues
2513
2514- Changed compiler flags, so that gcc is always invoked with -Wall and
2515 -Wstrict-prototypes. Users compiling Python with GCC should see
2516 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002517 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002518 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002519
Tim Petersa3a3a032000-11-30 05:22:44 +00002520- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002521
2522Tools and other miscellany
2523
2524- The compiler in Tools/compiler was updated to support the new
2525 language features introduced in 2.0: extended print statement, list
2526 comprehensions, and augmented assignments. The new compiler should
2527 also be backwards compatible with Python 1.5.2; the compiler will
2528 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002529 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002530
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002531What's new in 2.0 release candidate 1 (since beta 2)?
2532=====================================================
2533
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002534What is release candidate 1?
2535
2536We believe that release candidate 1 will fix all known bugs that we
2537intend to fix for the 2.0 final release. This release should be a bit
2538more stable than the previous betas. We would like to see even more
2539widespread testing before the final release, so we are producing this
2540release candidate. The final release will be exactly the same unless
2541any show-stopping (or brown bag) bugs are found by testers of the
2542release candidate.
2543
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002544All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002545to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002546
2547Core language, builtins, and interpreter
2548
2549- A bug that caused crashes when __coerce__ was used with augmented
2550 assignment, e.g. +=, was fixed.
2551
2552- Raise ZeroDivisionError when raising zero to a negative number,
2553 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2554 power operator and the result of math.pow(0.0, -2.0) will vary by
2555 platform. On Linux, it raises a ValueError.
2556
2557- A bug in Unicode string interpolation was fixed that occasionally
2558 caused errors with formats including "%%". For example, the
2559 following expression "%% %s" % u"abc" no longer raises a TypeError.
2560
2561- Compilation of deeply nested expressions raises MemoryError instead
2562 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2563
2564- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2565 rendering them useless. They are now written in binary mode again.
2566
2567Standard library
2568
2569- Keyword arguments are now accepted for most pattern and match object
2570 methods in SRE, the standard regular expression engine.
2571
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002572- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002573 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002574
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002575- Several bugs in the Unicode handling and error handling in _tkinter
2576 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002577
2578- Fix memory management errors in Merge() and Tkapp_Call() routines.
2579
2580- Several changes were made to cStringIO to make it compatible with
2581 the file-like object interface and with StringIO. If operations are
2582 performed on a closed object, an exception is raised. The truncate
2583 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002584 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002585
2586- There were many changes made to the linuxaudiodev module and its
2587 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002588 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002589
2590 Note that this module is named poorly, because it should work
2591 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002592 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002593
2594 The module now raises exceptions when errors occur instead of
2595 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2596 audio) and defines a getptr() method that calls the
2597 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2598
2599- The library_version attribute, introduced in an earlier beta, was
2600 removed because it can not be supported with early versions of the C
2601 readline library, which provides no way to determine the version at
2602 compile-time.
2603
2604- The binascii module is now enabled on Win64.
2605
Tim Peters46446d62000-10-09 21:19:31 +00002606- tokenize.py no longer suffers "recursion depth" errors when parsing
2607 programs with very long string literals.
2608
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002609Internals
2610
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002611- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002612 which is called when the interpreter starts up to determine where
2613 the standard library is installed. These vulnerabilities affect all
2614 previous versions of Python and can be exploited by setting very
2615 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2616 setuid Python script, although use of the wrapper in
2617 Misc/setuid-prog.c will eliminate the vulnerability.
2618
2619- Fixed garbage collection bugs in instance creation that were
2620 triggered when errors occurred during initialization. The solution,
2621 applied in cPickle and in PyInstance_New(), is to call
2622 PyObject_GC_Init() after the initialization of the object's
2623 container attributes is complete.
2624
2625- pyexpat adds definitions of PyModule_AddStringConstant and
2626 PyModule_AddObject if the Python version is less than 2.0, which
2627 provides compatibility with PyXML on Python 1.5.2.
2628
2629- If the platform has a bogus definition for LONG_BIT (the number of
2630 bits in a long), an error will be reported at compile time.
2631
2632- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2633 collection crashes and possibly other, unreported crashes.
2634
2635- Fixed a memory leak in _PyUnicode_Fini().
2636
2637Build issues
2638
2639- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002640 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002641 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002642
2643- The mmap.PAGESIZE constant is now initialized using sysconf when
2644 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2645
2646- The md5 file should now compile on all platforms.
2647
2648- The select module now compiles on platforms that do not define
2649 POLLRDNORM and related constants.
2650
2651- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002652 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002653
Jeremy Hylton10921202000-10-09 18:34:12 +00002654- BeOS: A number of changes were made to the build and installation
2655 process. ar-fake now operates on a directory of object files.
2656 dl_export.h is gone, and its macros now appear on the mwcc command
2657 line during build on PPC BeOS.
2658
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002659- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002660 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002661
2662- Cygwin: Support for shared libraries, Tkinter, and sockets.
2663
2664- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2665
2666Tools and other miscellany
2667
2668- Removed debugging prints from main used with freeze.
2669
Tim Peters46446d62000-10-09 21:19:31 +00002670- IDLE auto-indent no longer crashes when it encounters Unicode
2671 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002672
2673What's new in 2.0 beta 2 (since beta 1)?
2674========================================
2675
2676Core language, builtins, and interpreter
2677
Tim Peters482c0212000-09-26 06:33:09 +00002678- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002679 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002680
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002681- Add -h and -V command line options to print the usage message and
2682 Python version number and exit immediately.
2683
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002684- eval() and exec accept Unicode objects as code parameters.
2685
2686- getattr() and setattr() now also accept Unicode objects for the
2687 attribute name, which are converted to strings using the default
2688 encoding before lookup.
2689
2690- Multiplication on string and Unicode now does proper bounds
2691 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2692 string is too long."
2693
2694- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002695 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002696
Jeremy Hylton1b618592000-09-26 05:32:36 +00002697
2698Standard library and extensions
2699
Guido van Rossum5b08f132001-04-16 02:05:23 +00002700- socket module: the OpenSSL code now adds support for RAND_status()
2701 and EGD (Entropy Gathering Device).
2702
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002703- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002704 argument checking; it still takes no arguments.
2705
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002706- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002707
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002708- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002709
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002710- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002711
2712- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002713 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002714
2715- copy: Copy Unicode objects atomically.
2716
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002717- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002719- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002720
Fred Drake67233bc2000-09-26 16:40:27 +00002721- dbm: Add get() and setdefault() methods to dbm object. Add constant
2722 `library' to module that names the library used. Added doc strings
2723 and method names to error messages. Uses configure to determine
2724 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2725 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002726
2727- distutils: Update to version 0.9.3.
2728
2729- dl: Add several dl.RTLD_ constants.
2730
2731- fpectl: Now supported on FreeBSD.
2732
2733- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2734 found by the collector will be saved in gc.garbage. This is useful
2735 for debugging a program that creates reference cycles.
2736
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002737- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002738 of HTTP class. Do not close socket on zero-length response. Do not
2739 crash when server sends invalid content-length header.
2740
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002741- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002742
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002743- marshal: When reading a short, sign-extend on platforms where shorts
2744 are bigger than 16 bits. When reading a long, repair the unportable
2745 sign extension that was being done for 64-bit machines. (It assumed
2746 that signed right shift sign-extends.)
2747
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002748- operator: Add contains(), invert(), __invert__() as aliases for
2749 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002750
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002751- os: Add support for popen2() and popen3() on all platforms where
2752 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002753
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002754- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002755 clicking on a file in Explorer (or passing the file name to the
2756 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002757
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002758- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002759 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002760
2761- pickle: Now raises ValueError when an invalid pickle that contains
2762 a non-string repr where a string repr was expected. This behavior
2763 matches cPickle.
2764
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002765- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002766
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002767- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002768
2769- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002770 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002771 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002772
2773- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002774 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002775
2776- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002777 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002778 few cycles during startup since the first call to
2779 setdefaultencoding() will initialize the codec registry and the
2780 encodings package.
2781
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002782- socket: Support for size hint in readlines() method of object returned
2783 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002784
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002785- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002786 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002787 is followed by whitespace.
2788
Tim Petersa3a3a032000-11-30 05:22:44 +00002789- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002790
2791- struct: Check ranges for bytes and shorts.
2792
2793- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002794 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002795
2796- Tkinter: Image objects are now guaranteed to have unique ids. Set
2797 event.delta to zero if Tk version doesn't support mousewheel.
2798 Removed some debugging prints.
2799
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002800- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002801
Fred Drake67233bc2000-09-26 16:40:27 +00002802- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002803 which works around a bug in Norton AntiVirus 2000 that leads directly
2804 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002805
2806- xml: New version detection code allows PyXML to override standard
2807 XML package if PyXML version is greater than 0.6.1.
2808
Fred Drake64bb3802000-09-26 16:21:35 +00002809- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2810 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2811 tree only for nodes which are sufficiently interesting to a specific
2812 application. Does not provide the HTML-specific extensions. Still
2813 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002814
Fred Drake64bb3802000-09-26 16:21:35 +00002815- xml.sax: SAX 2 support for Python, including all the handler
2816 interfaces needed to process XML 1.0 compliant XML. Some
2817 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002818
Fred Drake64bb3802000-09-26 16:21:35 +00002819- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2820 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002821
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002822
Jeremy Hylton1b618592000-09-26 05:32:36 +00002823C API
2824
2825- Add three new convenience functions for module initialization --
2826 PyModule_AddObject(), PyModule_AddIntConstant(), and
2827 PyModule_AddStringConstant().
2828
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002829- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002830 removed and add #error to Python.h if NULL isn't defined after
2831 #include of stdio.h.
2832
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002833- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002834 backwards compatibility (at the source level) with old extensions.
2835
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002836- A wrapper API was added for signal() and sigaction(). Instead of
2837 either function, always use PyOS_getsig() to get a signal handler
2838 and PyOS_setsig() to set one. A new convenience typedef
2839 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002840
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002841- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002842 internal data buffer and size of a string object -- or the default
2843 encoded version of a Unicode object.
2844
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002845- PyString_Size() and PyString_AsString() accept Unicode objects.
2846
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002847- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002848 exists). INT_MAX and LONG_MAX will always be defined, even if
2849 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002850
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002851- PyFloat_FromString takes a second argument, pend, that was
2852 effectively useless. It is now officially useless but preserved for
2853 backwards compatibility. If the pend argument is not NULL, *pend is
2854 set to NULL.
2855
2856- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2857 for the attribute name. See note on getattr() above.
2858
2859- A few bug fixes to argument processing for Unicode.
2860 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2861 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2862 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002863 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002864
2865- Py_BuildValue accepts B format (for bgen-generated code).
2866
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002867
Jeremy Hylton1b618592000-09-26 05:32:36 +00002868Internals
2869
2870- On Unix, fix code for finding Python installation directory so that
2871 it works when argv[0] is a relative path.
2872
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002873- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002874 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002875 rather than by generating a copy of the object.
2876
Tim Peters482c0212000-09-26 06:33:09 +00002877- Several of the internal Unicode tables are much smaller now, and
2878 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002879
Jeremy Hylton97693b02000-09-26 17:42:51 +00002880- In the garbage collector: Fixed bug in collection of tuples. Fixed
2881 bug that caused some instances to be removed from the container set
2882 while they were still live. Fixed parsing in gc.set_debug() for
2883 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002884
2885- Fixed refcount problem in instance deallocation that only occurred
2886 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2887
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002888- On Windows, getpythonregpath is now protected against null data in
2889 registry key.
2890
2891- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002892 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002893
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002894
Jeremy Hylton1b618592000-09-26 05:32:36 +00002895Build and platform-specific issues
2896
2897- Better support of GNU Pth via --with-pth configure option.
2898
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002899- Python/C API now properly exposed to dynamically-loaded extension
2900 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002901
2902- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2903 Don't define MS_SYNC to be zero when it is undefined. Added missing
2904 prototypes in posixmodule.c.
2905
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002906- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002907 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002908
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002909- Fix largefile support on older NetBSD systems and OpenBSD by adding
2910 define for TELL64.
2911
2912
2913Tools and other miscellany
2914
2915- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2916
2917- freeze: The modulefinder now works with 2.0 opcodes.
2918
Tim Petersa3a3a032000-11-30 05:22:44 +00002919- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002920 Move hackery of sys.argv until after the Tk instance has been
2921 created, which allows the application-specific Tkinter
2922 initialization to be executed if present; also pass an explicit
2923 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002924
Jeremy Hylton1b618592000-09-26 05:32:36 +00002925
2926What's new in 2.0 beta 1?
2927=========================
2928
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002929Source Incompatibilities
2930------------------------
2931
2932None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2933such as single-argument append(), connect() and bind(), and changes to
2934str(long) and repr(float).
2935
2936
2937Binary Incompatibilities
2938------------------------
2939
2940- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2941with Python 2.0; these extensions will have to be rebuilt for Python
29422.0.
2943
2944- On Windows, attempting to import a third party extension built for
2945Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2946can do about this. Check your PYTHONPATH environment variable!
2947
2948- Python bytecode files (*.pyc and *.pyo) are not compatible between
2949releases.
2950
2951
2952Overview of Changes Since 1.6
2953-----------------------------
2954
2955There are many new modules (including brand new XML support through
2956the xml package, and i18n support through the gettext module); a list
2957of all new modules is included below. Lots of bugs have been fixed.
2958
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002959The process for making major new changes to the language has changed
2960since Python 1.6. Enhancements must now be documented by a Python
2961Enhancement Proposal (PEP) before they can be accepted.
2962
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002963There are several important syntax enhancements, described in more
2964detail below:
2965
2966 - Augmented assignment, e.g. x += 1
2967
2968 - List comprehensions, e.g. [x**2 for x in range(10)]
2969
2970 - Extended import statement, e.g. import Module as Name
2971
2972 - Extended print statement, e.g. print >> file, "Hello"
2973
2974Other important changes:
2975
2976 - Optional collection of cyclical garbage
2977
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002978Python Enhancement Proposal (PEP)
2979---------------------------------
2980
2981PEP stands for Python Enhancement Proposal. A PEP is a design
2982document providing information to the Python community, or describing
2983a new feature for Python. The PEP should provide a concise technical
2984specification of the feature and a rationale for the feature.
2985
2986We intend PEPs to be the primary mechanisms for proposing new
2987features, for collecting community input on an issue, and for
2988documenting the design decisions that have gone into Python. The PEP
2989author is responsible for building consensus within the community and
2990documenting dissenting opinions.
2991
2992The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002993
2994Augmented Assignment
2995--------------------
2996
2997This must have been the most-requested feature of the past years!
2998Eleven new assignment operators were added:
2999
Guido van Rossume905e952000-09-05 12:42:46 +00003000 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003001
3002For example,
3003
3004 A += B
3005
3006is similar to
3007
3008 A = A + B
3009
3010except that A is evaluated only once (relevant when A is something
3011like dict[index].attr).
3012
3013However, if A is a mutable object, A may be modified in place. Thus,
3014if A is a number or a string, A += B has the same effect as A = A+B
3015(except A is only evaluated once); but if a is a list, A += B has the
3016same effect as A.extend(B)!
3017
3018Classes and built-in object types can override the new operators in
3019order to implement the in-place behavior; the not-in-place behavior is
3020used automatically as a fallback when an object doesn't implement the
3021in-place behavior. For classes, the method name is derived from the
3022method name for the corresponding not-in-place operator by inserting
3023an 'i' in front of the name, e.g. __iadd__ implements in-place
3024__add__.
3025
3026Augmented assignment was implemented by Thomas Wouters.
3027
3028
3029List Comprehensions
3030-------------------
3031
3032This is a flexible new notation for lists whose elements are computed
3033from another list (or lists). The simplest form is:
3034
3035 [<expression> for <variable> in <sequence>]
3036
Guido van Rossum56db0952000-09-06 23:34:25 +00003037For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003038This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003039
3040You can also add a condition:
3041
3042 [<expression> for <variable> in <sequence> if <condition>]
3043
3044For example, [w for w in words if w == w.lower()] would yield the list
3045of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003046than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003047
3048You can also have nested for loops and more than one 'if' clause. For
3049example, here's a function that flattens a sequence of sequences::
3050
3051 def flatten(seq):
3052 return [x for subseq in seq for x in subseq]
3053
3054 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3055
3056This prints
3057
3058 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3059
3060List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003061Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003062
3063
3064Extended Import Statement
3065-------------------------
3066
3067Many people have asked for a way to import a module under a different
3068name. This can be accomplished like this:
3069
3070 import foo
3071 bar = foo
3072 del foo
3073
3074but this common idiom gets old quickly. A simple extension of the
3075import statement now allows this to be written as follows:
3076
3077 import foo as bar
3078
3079There's also a variant for 'from ... import':
3080
3081 from foo import bar as spam
3082
3083This also works with packages; e.g. you can write this:
3084
3085 import test.regrtest as regrtest
3086
3087Note that 'as' is not a new keyword -- it is recognized only in this
3088context (this is only possible because the syntax for the import
3089statement doesn't involve expressions).
3090
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003091Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003092
3093
3094Extended Print Statement
3095------------------------
3096
3097Easily the most controversial new feature, this extension to the print
3098statement adds an option to make the output go to a different file
3099than the default sys.stdout.
3100
3101For example, to write an error message to sys.stderr, you can now
3102write:
3103
3104 print >> sys.stderr, "Error: bad dog!"
3105
3106As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003107evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003108
3109 print >> None, "Hello world"
3110
3111is equivalent to
3112
3113 print "Hello world"
3114
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003115Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003116
3117
3118Optional Collection of Cyclical Garbage
3119---------------------------------------
3120
3121Python is now equipped with a garbage collector that can hunt down
3122cyclical references between Python objects. It's no replacement for
3123reference counting; in fact, it depends on the reference counts being
3124correct, and decides that a set of objects belong to a cycle if all
3125their reference counts can be accounted for from their references to
3126each other. This devious scheme was first proposed by Eric Tiedemann,
3127and brought to implementation by Neil Schemenauer.
3128
3129There's a module "gc" that lets you control some parameters of the
3130garbage collection. There's also an option to the configure script
3131that lets you enable or disable the garbage collection. In 2.0b1,
3132it's on by default, so that we (hopefully) can collect decent user
3133experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003134performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003135off by default in the final 2.0 release.
3136
3137
3138Smaller Changes
3139---------------
3140
3141A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3142map(None, seq1, seq2, ...) when the sequences have the same length;
3143i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3144the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003145zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003146
3147sys.version_info is a tuple (major, minor, micro, level, serial).
3148
3149Dictionaries have an odd new method, setdefault(key, default).
3150dict.setdefault(key, default) returns dict[key] if it exists; if not,
3151it sets dict[key] to default and returns that value. Thus:
3152
3153 dict.setdefault(key, []).append(item)
3154
3155does the same work as this common idiom:
3156
3157 if not dict.has_key(key):
3158 dict[key] = []
3159 dict[key].append(item)
3160
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003161There are two new variants of SyntaxError that are raised for
3162indentation-related errors: IndentationError and TabError.
3163
3164Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3165escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003166
3167The limits on the size of expressions and file in Python source code
3168have been raised from 2**16 to 2**32. Previous versions of Python
3169were limited because the maximum argument size the Python VM accepted
3170was 2**16. This limited the size of object constructor expressions,
3171e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3172limit was raised thanks to a patch by Charles Waldman that effectively
3173fixes the problem. It is now much more likely that you will be
3174limited by available memory than by an arbitrary limit in Python.
3175
3176The interpreter's maximum recursion depth can be modified by Python
3177programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3178limit is the maximum number of recursive calls that can be made by
3179Python code. The limit exists to prevent infinite recursion from
3180overflowing the C stack and causing a core dump. The default value is
31811000. The maximum safe value for a particular platform can be found
3182by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003183
3184New Modules and Packages
3185------------------------
3186
3187atexit - for registering functions to be called when Python exits.
3188
3189imputil - Greg Stein's alternative API for writing custom import
3190hooks.
3191
3192pyexpat - an interface to the Expat XML parser, contributed by Paul
3193Prescod.
3194
3195xml - a new package with XML support code organized (so far) in three
3196subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3197would fill a volume. There's a special feature whereby a
3198user-installed package named _xmlplus overrides the standard
3199xmlpackage; this is intended to give the XML SIG a hook to distribute
3200backwards-compatible updates to the standard xml package.
3201
3202webbrowser - a platform-independent API to launch a web browser.
3203
3204
Guido van Rossume905e952000-09-05 12:42:46 +00003205Changed Modules
3206---------------
3207
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003208array -- new methods for array objects: count, extend, index, pop, and
3209remove
3210
3211binascii -- new functions b2a_hex and a2b_hex that convert between
3212binary data and its hex representation
3213
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003214calendar -- Many new functions that support features including control
3215over which day of the week is the first day, returning strings instead
3216of printing them. Also new symbolic constants for days of week,
3217e.g. MONDAY, ..., SUNDAY.
3218
3219cgi -- FieldStorage objects have a getvalue method that works like a
3220dictionary's get method and returns the value attribute of the object.
3221
3222ConfigParser -- The parser object has new methods has_option,
3223remove_section, remove_option, set, and write. They allow the module
3224to be used for writing config files as well as reading them.
3225
3226ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003227optionally support the RFC 959 REST command.
3228
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003229gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003230
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003231httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3232the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003233
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003234locale -- implement getdefaultlocale for Win32 and Macintosh
3235
3236marshal -- no longer dumps core when marshaling deeply nested or
3237recursive data structures
3238
3239os -- new functions isatty, seteuid, setegid, setreuid, setregid
3240
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003241os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3242support under Unix.
3243
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003244os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003245
3246os.path -- fix semantics of os.path.commonprefix
3247
3248smtplib -- support for sending very long messages
3249
3250socket -- new function getfqdn()
3251
3252readline -- new functions to read, write and truncate history files.
3253The readline section of the library reference manual contains an
3254example.
3255
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003256select -- add interface to poll system call
3257
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003258shutil -- new copyfileobj function
3259
3260SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3261HTTP server.
3262
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003263Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003264
3265urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003266e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003267
3268whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003269
3270
3271Obsolete Modules
3272----------------
3273
3274None. However note that 1.6 made a whole slew of modules obsolete:
3275stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3276poly, zmod, strop, util, whatsound.
3277
3278
3279Changed, New, Obsolete Tools
3280----------------------------
3281
Tim Peters8b092332000-09-05 20:15:25 +00003282None.
Guido van Rossume905e952000-09-05 12:42:46 +00003283
3284
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003285C-level Changes
3286---------------
3287
3288Several cleanup jobs were carried out throughout the source code.
3289
3290All C code was converted to ANSI C; we got rid of all uses of the
3291Py_PROTO() macro, which makes the header files a lot more readable.
3292
3293Most of the portability hacks were moved to a new header file,
3294pyport.h; several other new header files were added and some old
3295header files were removed, in an attempt to create a more rational set
3296of header files. (Few of these ever need to be included explicitly;
3297they are all included by Python.h.)
3298
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003299Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003300and Win64, especially for the new Intel Itanium processor. Mick also
3301added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003302
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003303The C APIs to return an object's size have been update to consistently
3304use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3305previous versions, the abstract interfaces used PyXXX_Length and the
3306concrete interfaces used PyXXX_Size. The old names,
3307e.g. PyObject_Length, are still available for backwards compatibility
3308at the API level, but are deprecated.
3309
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003310The PyOS_CheckStack function has been implemented on Windows by
3311Fredrik Lundh. It prevents Python from failing with a stack overflow
3312on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003313
3314The GC changes resulted in creation of two new slots on object,
3315tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003316the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003317
3318The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003319C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003320
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003321PyErr_Format has been updated to automatically calculate the size of
3322the buffer needed to hold the formatted result string. This change
3323prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003324
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003325New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003326
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003327PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3328that are the same as their non-Ex counterparts except they take an
3329extra flag argument that tells them to close the file when done.
3330
3331XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003332
Tim Peters8b092332000-09-05 20:15:25 +00003333
3334Windows Changes
3335---------------
3336
3337New popen2/popen3/peopen4 in os module (see Changed Modules above).
3338
3339os.popen is much more usable on Windows 95 and 98. See Microsoft
3340Knowledge Base article Q150956. The Win9x workaround described there
3341is implemented by the new w9xpopen.exe helper in the root of your
3342Python installation. Note that Python uses this internally; it is not
3343a standalone program.
3344
3345Administrator privileges are no longer required to install Python
3346on Windows NT or Windows 2000. If you have administrator privileges,
3347Python's registry info will be written under HKEY_LOCAL_MACHINE.
3348Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003349under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003350uses of Python, but will prevent some advanced uses from working
3351(for example, running a Python script as an NT service, or possibly
3352from CGI).
3353
3354[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3355installer; instead, it installs the needed Tcl/Tk files directly in the
3356Python directory. If you already have a Tcl/Tk installation, this
3357wastes some disk space (about 4 Megs) but avoids problems with
3358conflicting Tcl/Tk installations, and makes it much easier for Python
3359to ensure that Tcl/Tk can find all its files.
3360
3361[This was new in 1.6] The Windows installer now installs by default in
3362\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3363
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003364
3365Updates to the changes between 1.5.2 and 1.6
3366--------------------------------------------
3367
3368The 1.6 NEWS file can't be changed after the release is done, so here
3369is some late-breaking news:
3370
3371New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3372and changes to getlocale() and setlocale().
3373
3374The new module is now enabled per default.
3375
3376It is not true that the encodings codecs cannot be used for normal
3377strings: the string.encode() (which is also present on 8-bit strings
3378!) allows using them for 8-bit strings too, e.g. to convert files from
3379cp1252 (Windows) to latin-1 or vice-versa.
3380
3381Japanese codecs are available from Tamito KAJIYAMA:
3382http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3383
3384
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003385======================================================================