blob: bb5792cd662a36ffdcacd585da433b6175c74f69 [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 Rossum8ace1ab2002-04-06 01:05:01 +00009- Changed new-style class instantiation so that when C's __new__
10 method returns something that's not a C instance, its __init__ is
11 not called. [SF bug #537450]
12
Guido van Rossum181e41a2002-04-06 00:23:25 +000013- Fixed super() to work correctly with class methods. [SF bug #535444]
14
Guido van Rossum47834462002-04-04 15:21:33 +000015- A new built-in type, bool, has been added, as well as built-in
16 names for its two values, True and False. Comparisons and sundry
17 other operations that return a truth value have been changed to
18 return a bool instead. Read PEP 285 for an explanantion of why this
19 is backward compatible.
20
Guido van Rossum95b62a62002-03-29 01:07:24 +000021- Fixed two bugs reported as SF #535905: under certain conditions,
22 deallocating a deeply nested structure could cause a segfault in the
23 garbage collector, due to interaction with the "trashcan" code;
24 access to the current frame during destruction of a local variable
25 could access a pointer to freed memory.
26
Neil Schemenauer9d50d132002-03-22 17:06:59 +000027- The optional object allocator has been enabled by default.
28
Guido van Rossum8c842552002-03-14 23:05:54 +000029- If you try to pickle an instance of a class that has __slots__ but
30 doesn't define or override __getstate__, a TypeError is now raised.
31 This is done by adding a bozo __getstate__ to the class that always
32 raises TypeError. (Before, this would appear to be pickled, but the
33 state of the slots would be lost.)
34
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000035- PyErr_Display will provide file and line information for all exceptions
36 that have an attribute print_file_and_line, not just SyntaxErrors.
37
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000038- The UTF-8 codec will now encode and decode Unicode surrogates
39 correctly and without raising exceptions for unpaired ones.
40
Neal Norwitz649b7592002-01-01 19:07:13 +000041- file.xreadlines() now raises a ValueError if the file is closed:
42 Previously, an xreadlines object was returned which would raise
43 a ValueError when the xreadlines.next() method was called.
44
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000045- posix.killpg has been added where available.
46
Neal Norwitz0c766a02002-03-27 13:03:09 +000047- sys.exit() inadvertantly allowed more than one argument.
48 An exception will now be raised if more than one argument is used.
49
Tim Petersaf8446f2001-12-21 21:36:50 +000050Extension modules
51
Martin v. Löwis2e64c342002-03-27 18:49:02 +000052- The locale module now exposes the C library's gettext interface.
53
Tim Petersfbf74f22002-03-14 19:06:01 +000054- A security hole ("double free") was found in zlib-1.1.3, a popular
55 third party compression library used by some Python modules. The
56 hole was quickly plugged in zlib-1.1.4, and the Windows build of
57 Python now ships with zlib-1.1.4.
58
Martin v. Löwis29001ff2002-03-01 10:47:37 +000059- pwd and grp return enhanced tuples now, with symbolic field names.
60
Martin v. Löwis99866332002-03-01 10:27:01 +000061- array.array is now a type object. A new format character
62 'u' indicates Py_UNICODE arrays. For those, .tounicode and
63 .fromunicode methods are available. Arrays now support __iadd__
64 and __imul__.
65
Neal Norwitze790eae2002-01-01 21:14:12 +000066- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000067 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
68 is called.
69
Tim Petersaf8446f2001-12-21 21:36:50 +000070Library
71
Marc-André Lemburg4179a012002-04-05 12:15:05 +000072- The UTF-16, -LE and -BE now raise a NotImplementedError
73 for all calls to .readline(). Previously, they used to just
74 produce garbage or fail with an encoding error -- UTF-16 is
75 a 2-byte encoding and the C lib's line reading APIs don't
76 work well with these.
77
Martin v. Löwis5c137c22002-03-18 12:44:08 +000078- compileall now supports quiet operation.
79
Martin v. Löwis587c98c2002-03-17 18:37:22 +000080- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
81 connections.
82
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000083- socket module: the SSL support was broken out of the main
84 _socket module C helper and placed into a new _ssl helper
85 which now gets imported by socket.py if available and working.
86
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000087- encodings package: added aliases for all supported IANA character
88 sets
89
Guido van Rossum606fe4e2001-12-28 20:57:14 +000090- ftplib: to safeguard the user's privacy, anonymous login will use
91 "anonymous@" as default password, rather than the real user and host
92 name.
93
Fred Drake36736122002-01-10 13:50:31 +000094- webbrowser: tightened up the command passed to os.system() so that
95 arbitrary shell code can't be executed because a bogus URL was
96 passed in.
97
Tim Peters11bd9942002-02-01 00:52:29 +000098- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000099 gettext.find an optional all argument. Translations will now fallback
100 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000101
Martin v. Löwis9668b932002-01-12 11:27:42 +0000102- distutils bdist commands now offer a --skip-build option.
103
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000104- warnings.warn now accepts a Warning instance as first argument.
105
Fred Drakefed7e852002-04-04 19:36:15 +0000106- The xml.sax.expatreader.ExpatParser class will no longer create
107 circular references by using itself as the locator that gets passed
108 to the content handler implementation. [SF bug #535474]
109
Tim Petersaf8446f2001-12-21 21:36:50 +0000110Tools/Demos
111
Marc-André Lemburg46260092002-04-04 16:17:11 +0000112- freeze.py now produces binaries which can import shared modules,
113 unlike before when this failed due to missing symbol exports in
114 the generated binary.
115
Tim Petersaf8446f2001-12-21 21:36:50 +0000116Build
117
Martin v. Löwis1142de32002-03-29 16:28:31 +0000118- On Unix, a shared libpython2.3.so can be created with --enable-shared.
119
Tim Peters8deda702002-03-30 10:06:07 +0000120- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
121 preprocessor symbols were eliminated. The internal decisions they
122 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000123
Tim Petersaf8446f2001-12-21 21:36:50 +0000124C API
125
Guido van Rossum0986d822002-04-08 01:38:42 +0000126- A type can now inherit its metatype from its base type. Previously,
127 when PyType_Ready() was called, if ob_type was found to be NULL, it
128 was always set to &PyType_Type; now it is set to base->ob_type,
129 where base is tp_base, defaulting to &PyObject_Type.
130
131- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
132
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000133- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
134 functions will be allocated using pymalloc if it is enabled. These
135 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
136 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
137 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
138 PyCore_* family of APIs have been removed.
139
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000140- The "u#" parser marker will now pass through Unicode object as-is
141 without going through the buffer API.
142
Martin v. Löwis7198a522002-01-01 19:59:11 +0000143- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
144
Tim Peters10a3bb52001-12-25 19:07:38 +0000145- An old #define of ANY as void has been removed from pyport.h. This
146 hasn't been used since Python's pre-ANSI days, and the #define has
147 been marked as obsolete since then. SF bug 495548 says it created
148 conflicts with other packages, so keeping it around wasn't harmless.
149
Tim Petersaf8446f2001-12-21 21:36:50 +0000150- Because Python's magic number scheme broke on January 1st, we decided
151 to stop Python development. Thanks for all the fish!
152
Tim Petersfb05db22002-03-11 00:24:00 +0000153- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000154 scheme to a new one. See Python/import.c for details.
155
Tim Petersaf8446f2001-12-21 21:36:50 +0000156New platforms
157
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000158- GNU/Hurd is now supported.
159
Tim Petersaf8446f2001-12-21 21:36:50 +0000160Tests
161
162Windows
163
Guido van Rossum181e41a2002-04-06 00:23:25 +0000164- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
165
Tim Peters33187922002-04-04 20:02:04 +0000166- The installer now installs Start menu shortcuts under (the local
167 equivalent of) "All Users" when doing an Admin install.
168
Tim Petersfb05db22002-03-11 00:24:00 +0000169- file.truncate([newsize]) now works on Windows for all newsize values.
170 It used to fail if newsize didn't fit in 32 bits, reflecting a
171 limitation of MS _chsize (which is no longer used).
172
Tim Petersab034fa2002-02-01 11:27:43 +0000173- os.waitpid() is now implemented for Windows, and can be used to block
174 until a specified process exits. This is similar to, but not exactly
175 the same as, os.waitpid() on POSIX systems. If you're waiting for
176 a specific process whose pid was obtained from one of the spawn()
177 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000178 See the docs for details. The docs were changed to clarify that
179 spawn functions return, and waitpid requires, a process handle on
180 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000181
Tim Peters11bd9942002-02-01 00:52:29 +0000182- New tempfile.TemporaryFile implementation for Windows: this doesn't
183 need a TemproraryFileWrapper wrapper anymore, and should be immune
184 to a nasty problem: before 2.3, if you got a temp file on Windows, it
185 got wrapped in an object whose close() method first closed the
186 underlying file, then deleted the file. This usually worked fine.
187 However, the spawn family of functions on Windows create (at a low C
188 level) the same set of open files in the spawned process Q as were
189 open in the spawning process P. If a temp file f was among them, then
190 doing f.close() in P first closed P's C-level file handle on f, but Q's
191 C-level file handle on f remained open, so the attempt in P to delete f
192 blew up with a "Permission denied" error (Windows doesn't allow
193 deleting open files). This was surprising, subtle, and difficult to
194 work around.
195
196- The os module now exports all the symbolic constants usable with the
197 low-level os.open() on Windows: the new constants in 2.3 are
198 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
199 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
200 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
201 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
202 (so specify both if you want both; note that neither is useful unless
203 specified with O_CREAT too).
204
Tim Petersaf8446f2001-12-21 21:36:50 +0000205Mac
206
207
Tim Peters909c0912001-12-14 23:16:18 +0000208What's New in Python 2.2 final?
209Release date: 21-Dec-2001
210===============================
211
212Type/class unification and new-style classes
213
Barry Warsaw52acb492001-12-21 20:04:22 +0000214- pickle.py, cPickle: allow pickling instances of new-style classes
215 with a custom metaclass.
216
Tim Peters909c0912001-12-14 23:16:18 +0000217Core and builtins
218
Barry Warsaw52acb492001-12-21 20:04:22 +0000219- weakref proxy object: when comparing, unwrap both arguments if both
220 are proxies.
221
Tim Peters909c0912001-12-14 23:16:18 +0000222Extension modules
223
Barry Warsaw52acb492001-12-21 20:04:22 +0000224- binascii.b2a_base64(): fix a potential buffer overrun when encoding
225 very short strings.
226
227- cPickle: the obscure "fast" mode was suspected of causing stack
228 overflows on the Mac. Hopefully fixed this by setting the recursion
229 limit much smaller. If the limit is too low (it only affects
230 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
231 when compiling cPickle.c (or in pyconfig.h).
232
Tim Peters909c0912001-12-14 23:16:18 +0000233Library
234
Barry Warsaw52acb492001-12-21 20:04:22 +0000235- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
236 close or delete time).
237
238- rfc822.py: fixed a bug where the address '<>' was converted to None
239 instead of an empty string (also fixes the email.Utils module).
240
241- xmlrpclib.py: version 1.0.0; uses precision for doubles.
242
243- test suite: the pickle and cPickle tests were not executing any code
244 when run from the standard regresssion test.
245
Tim Peters909c0912001-12-14 23:16:18 +0000246Tools/Demos
247
248Build
249
250C API
251
252New platforms
253
254Tests
255
256Windows
257
Barry Warsaw52acb492001-12-21 20:04:22 +0000258- distutils package: fixed broken Windows installers (bdist_wininst).
259
260- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
261 instances are deleted at process exit time.
262
263- socket.py: prevent mysterious warnings when socket instances are
264 deleted at process exit time.
265
266- posixmodule.c: fix a Windows crash with stat() of a filename ending
267 in backslash.
268
Tim Peters909c0912001-12-14 23:16:18 +0000269Mac
270
Barry Warsaw52acb492001-12-21 20:04:22 +0000271- The Carbon toolbox modules have been upgraded to Universal Headers
272 3.4, and experimental CoreGraphics and CarbonEvents modules have
273 been added. All only for framework-enabled MacOSX.
274
Tim Peters909c0912001-12-14 23:16:18 +0000275
Tim Peters6272dfd2001-12-13 19:34:00 +0000276What's New in Python 2.2c1?
277Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000278===========================
279
280Type/class unification and new-style classes
281
Barry Warsaw06557452001-12-14 20:47:12 +0000282- Guido's tutorial introduction to the new type/class features has
283 been extensively updated. See
284
285 http://www.python.org/2.2/descrintro.html
286
287 That remains the primary documentation in this area.
288
Guido van Rossum33bab012001-12-05 22:45:48 +0000289- Fixed a leak: instance variables declared with __slots__ were never
290 deleted!
291
Guido van Rossum4b800852001-12-03 00:54:52 +0000292- The "delete attribute" method of descriptor objects is called
293 __delete__, not __del__. In previous releases, it was mistakenly
294 called __del__, which created an unfortunate overloading condition
295 with finalizers. (The "get attribute" and "set attribute" methods
296 are still called __get__ and __set__, respectively.)
297
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000298- Some subtle issues with the super built-in were fixed:
299
300 (a) When super itself is subclassed, its __get__ method would still
301 return an instance of the base class (i.e., of super).
302
303 (b) super(C, C()).__class__ would return C rather than super. This
304 is confusing. To fix this, I decided to change the semantics of
305 super so that it only applies to code attributes, not to data
306 attributes. After all, overriding data attributes is not
307 supported anyway.
308
309 (c) The __get__ method didn't check whether the argument was an
310 instance of the type used in creation of the super instance.
311
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000312- Previously, hash() of an instance of a subclass of a mutable type
313 (list or dictionary) would return some value, rather than raising
314 TypeError. This has been fixed. Also, directly calling
315 dict.__hash__ and list.__hash__ now raises the same TypeError
316 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000317
Guido van Rossumd331cb52001-12-05 19:46:42 +0000318- New-style objects now support deleting their __dict__. This is for
319 all intents and purposes equivalent to assigning a brand new empty
320 dictionary, but saves space if the object is not used further.
321
Tim Petersb3c9af12001-11-17 00:21:57 +0000322Core and builtins
323
Tim Peters3caca232001-12-06 06:23:26 +0000324- -Qnew now works as documented in PEP 238: when -Qnew is passed on
325 the command line, all occurrences of "/" use true division instead
326 of classic division. See the PEP for details. Note that "all"
327 means all instances in library and 3rd-party modules, as well as in
328 your own code. As the PEP says, -Qnew is intended for use only in
329 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000330 Note that test_coercion.py in the standard Python test suite fails
331 under -Qnew; this is expected, and won't be repaired until true
332 division becomes the default (in the meantime, test_coercion is
333 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000334
Fred Drake6c01e252001-12-14 17:08:12 +0000335- complex() now only allows the first argument to be a string
336 argument, and raises TypeError if either the second arg is a string
337 or if the second arg is specified when the first is a string.
338
Tim Petersb3c9af12001-11-17 00:21:57 +0000339Extension modules
340
Martin v. Löwis560da622001-11-24 09:24:51 +0000341- gc.get_referents was renamed to gc.get_referrers.
342
Tim Petersb3c9af12001-11-17 00:21:57 +0000343Library
344
Tim Peters25059d32001-12-07 20:35:43 +0000345- Functions in the os.spawn() family now release the global interpreter
346 lock around calling the platform spawn. They should always have done
347 this, but did not before 2.2c1. Multithreaded programs calling
348 an os.spawn function with P_WAIT will no longer block all Python threads
349 until the spawned program completes. It's possible that some programs
350 relies on blocking, although more likely by accident than by design.
351
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000352- webbrowser defaults to netscape.exe on OS/2 now.
353
Martin v. Löwis652e1912001-11-25 14:50:56 +0000354- Tix.ResizeHandle exposes detach_widget, hide, and show.
355
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000356- The charset alias windows_1252 has been added.
357
Barry Warsaw06557452001-12-14 20:47:12 +0000358- types.StringTypes is a tuple containing the defined string types;
359 usually this will be (str, unicode), but if Python was compiled
360 without Unicode support it will be just (str,).
361
362- The pulldom and minidom modules were synchronized to PyXML.
363
Tim Petersb3c9af12001-11-17 00:21:57 +0000364Tools/Demos
365
Barry Warsaw06557452001-12-14 20:47:12 +0000366- A new script called Tools/scripts/google.py was added, which fires
367 off a search on Google.
368
Tim Petersb3c9af12001-11-17 00:21:57 +0000369Build
370
Barry Warsaw06557452001-12-14 20:47:12 +0000371- Note that release builds of Python should arrange to define the
372 preprocessor symbol NDEBUG on the command line (or equivalent).
373 In the 2.2 pre-release series we tried to define this by magic in
374 Python.h instead, but it proved to cause problems for extension
375 authors. The Unix, Windows and Mac builds now all define NDEBUG in
376 release builds via cmdline (or equivalent) instead. Ports to
377 other platforms should do likewise.
378
Jack Jansen1999ef42001-12-06 21:47:20 +0000379- It is no longer necessary to use --with-suffix when building on a
380 case-insensitive file system (such as Mac OS X HFS+). In the build
381 directory an extension is used, but not in the installed python.
382
Tim Petersb3c9af12001-11-17 00:21:57 +0000383C API
384
Tim Petersf582b822001-12-11 18:51:08 +0000385- New function PyDict_MergeFromSeq2() exposes the builtin dict
386 constructor's logic for updating a dictionary from an iterable object
387 producing key-value pairs.
388
Tim Peterscffed4b2001-11-29 03:26:37 +0000389- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000390 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000391 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
392 dump core in some bad cases. This has been repaired. As a result,
393 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
394 previously went unchallenged.
395
Tim Petersb3c9af12001-11-17 00:21:57 +0000396New platforms
397
398Tests
399
400Windows
401
402Mac
403
Jack Jansenffa260f2001-12-06 21:14:00 +0000404- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
405 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000406
Barry Warsaw06557452001-12-14 20:47:12 +0000407- Changed logic for finding python home in Mac OS X framework Pythons.
408 Now sys.executable points to the executable again, in stead of to
409 the shared library. The latter is used only for locating the python
410 home.
411
412
Tim Peters84362bc2001-10-19 17:55:30 +0000413What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000414Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000415===========================
416
417Type/class unification and new-style classes
418
Guido van Rossum3d27df02001-11-15 20:27:54 +0000419- Multiple inheritance mixing new-style and classic classes in the
420 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000421
422 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000423 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000424
425 The MRO (method resolution order) for each base class is respected
426 according to its kind, but the MRO for the derived class is computed
427 using new-style MRO rules if any base clase is a new-style class.
428 This needs to be documented.
429
Tim Petersa427a2b2001-10-29 22:25:45 +0000430- The new builtin dictionary() constructor, and dictionary type, have
431 been renamed to dict. This reflects a decade of common usage.
432
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000433- dict() now accepts an iterable object producing 2-sequences. For
434 example, dict(d.items()) == d for any dictionary d. The argument,
435 and the elements of the argument, can be any iterable objects.
436
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000437- New-style classes can now have a __del__ method, which is called
438 when the instance is deleted (just like for classic classes).
439
Guido van Rossum12d955c2001-10-26 14:56:06 +0000440- Assignment to object.__dict__ is now possible, for objects that are
441 instances of new-style classes that have a __dict__ (unless the base
442 class forbids it).
443
Guido van Rossumc8e56452001-10-22 00:43:43 +0000444- Methods of built-in types now properly check for keyword arguments
445 (formerly these were silently ignored). The only built-in methods
446 that take keyword arguments are __call__, __init__ and __new__.
447
Guido van Rossum86443212001-10-27 22:28:54 +0000448- The socket function has been converted to a type; see below.
449
Tim Peters84362bc2001-10-19 17:55:30 +0000450Core and builtins
451
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000452- Assignment to __debug__ raises SyntaxError at compile-time. This
453 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000454 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000455
Guido van Rossum12d955c2001-10-26 14:56:06 +0000456- Clarified the error messages for unsupported operands to an operator
457 (like 1 + '').
458
Tim Peters84362bc2001-10-19 17:55:30 +0000459Extension modules
460
Tim Peters5ebfd362001-11-13 23:11:19 +0000461- mmap has a new keyword argument, "access", allowing a uniform way for
462 both Windows and Unix users to create read-only, write-through and
463 copy-on-write memory mappings. This was previously possible only on
464 Unix. A new keyword argument was required to support this in a
465 uniform way because the mmap() signuatures had diverged across
466 platforms. Thanks to Jay T Miller for repairing this!
467
Tim Peters169ded02001-11-03 19:57:21 +0000468- By default, the gc.garbage list now contains only those instances in
469 unreachable cycles that have __del__ methods; in 2.1 it contained all
470 instances in unreachable cycles. "Instances" here has been generalized
471 to include instances of both new-style and old-style classes.
472
Guido van Rossum12d955c2001-10-26 14:56:06 +0000473- The socket module defines a new method for socket objects,
474 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000475 send() until all data has been sent. Also, the socket function has
476 been converted to a subclassable type, like list and tuple (etc.)
477 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000478
479- Various bugfixes to the curses module. There is now a test suite
480 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000481
Guido van Rossum692adf12001-10-30 03:03:03 +0000482- binascii.b2a_base64 no longer places an arbitrary restriction of 57
483 bytes on its input.
484
Tim Peters84362bc2001-10-19 17:55:30 +0000485Library
486
Tim Peters5ebfd362001-11-13 23:11:19 +0000487- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000488 convenience function.
489
Tim Peters75335872001-11-03 19:35:43 +0000490- Symbolic group names in regular expressions must be unique. For
491 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
492 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000493 Python 2.2 detects this error at regexp compilation time;
494 previously, the error went undetected, and results were
495 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
496 pattern.subn() methods have been rewritten in C. Also, an
497 experimental function/method finditer() has been added, which works
498 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000499
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000500- Tix exposes more commands through the classes DirSelectBox,
501 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
502 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
503 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
504
Tim Peters98791af2001-10-23 01:59:54 +0000505- Traceback objects are now scanned by cyclic garbage collection, so
506 cycles created by casual use of sys.exc_info() no longer cause
507 permanent memory leaks (provided garbage collection is enabled).
508
Guido van Rossum49192142001-10-24 20:51:44 +0000509- os.extsep -- a new variable needed by the RISCOS support. It is the
510 separator used by extensions, and is '.' on all platforms except
511 RISCOS, where it is '/'. There is no need to use this variable
512 unless you have a masochistic desire to port your code to RISCOS.
513
Barry Warsaw012852b2001-11-16 16:17:27 +0000514- mimetypes.py has optional support for non-standard, but commonly
515 found types. guess_type() and guess_extension() now accept an
516 optional `strict' flag, defaulting to true, which controls whether
517 recognize non-standard types or not. A few non-standard types we
518 know about have been added. Also, when run as a script, there are
519 new -l and -e options.
520
521- statcache is now deprecated.
522
523- email.Utils.formatdate() now produces the preferred RFC 2822 style
524 dates with numeric timezones (it used to produce obsolete dates
525 hard coded to "GMT" timezone). An optional `localtime' flag is
526 added to produce dates in the local timezone, with daylight savings
527 time properly taken into account.
528
529- In pickle and cPickle, instead of masking errors in load() by
530 transforming them into SystemError, we let the original exception
531 propagate out. Also, implement support for __safe_for_unpickling__
532 in pickle, as it already was supported in cPickle.
533
Tim Peters84362bc2001-10-19 17:55:30 +0000534Tools/Demos
535
536Build
537
Barry Warsaw012852b2001-11-16 16:17:27 +0000538- The dbm module is built using libdb1 if available. The bsddb module
539 is built with libdb3 if available.
540
541- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
542
Tim Peters84362bc2001-10-19 17:55:30 +0000543C API
544
Tim Peters1fc240e2001-10-26 05:06:50 +0000545- New function PySequence_Fast_GET_SIZE() returns the size of a non-
546 NULL result from PySequence_Fast(), more quickly than calling
547 PySequence_Size().
548
Barry Warsaw012852b2001-11-16 16:17:27 +0000549- New argument unpacking function PyArg_UnpackTuple() added.
550
551- New functions PyObject_CallFunctionObjArgs() and
552 PyObject_CallMethodObjArgs() have been added to make it more
553 convenient and efficient to call functions and methods from C.
554
555- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
556 possible that this will propagate errors it didn't before.
557
558- New function PyObject_CheckReadBuffer(), which returns true if its
559 argument supports the single-segment readable buffer interface.
560
Tim Peters84362bc2001-10-19 17:55:30 +0000561New platforms
562
Guido van Rossum86443212001-10-27 22:28:54 +0000563- We've finally confirmed that this release builds on HP-UX 11.00,
564 *with* threads, and passes the test suite.
565
Tim Peters7a33d8b2001-11-05 02:51:07 +0000566- Thanks to a series of patches from Michael Muller, Python may build
567 again under OS/2 Visual Age C++.
568
Guido van Rossum49192142001-10-24 20:51:44 +0000569- Updated RISCOS port by Dietmar Schwertberger.
570
Tim Peters84362bc2001-10-19 17:55:30 +0000571Tests
572
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000573- Added a test script for the curses module. It isn't run automatically;
574 regrtest.py must be run with '-u curses' to enable it.
575
Tim Peters84362bc2001-10-19 17:55:30 +0000576Windows
577
Barry Warsaw012852b2001-11-16 16:17:27 +0000578Mac
579
580- PythonScript has been moved to unsupported and is slated to be
581 removed completely in the next release.
582
583- It should now be possible to build applets that work on both OS9 and
584 OSX.
585
586- The core is now linked with CoreServices not Carbon; as a side
587 result, default 8bit encoding on OSX is now ASCII.
588
589- Python should now build on OSX 10.1.1
590
Tim Peters84362bc2001-10-19 17:55:30 +0000591
Tim Petersabf925f2001-09-28 21:53:42 +0000592What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000593Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000594===========================
595
596Type/class unification and new-style classes
597
Guido van Rossum687ae002001-10-15 22:03:32 +0000598- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000599 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000600 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000601 remains: the __dict__ of a new-style class is a read-only proxy; you
602 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000603 __defined__ attribute of new-style types no longer exists, for lack
604 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000605 future a __cache__ may be resurrected with a similar function, if I
606 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000607
Tim Peters1c9ca872001-10-04 06:43:12 +0000608- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
609 always returned None, even when there was a class docstring).
610
611- doctest now finds and runs docstrings attached to new-style classes,
612 class methods, static methods, and properties.
613
Guido van Rossum9074ef62001-10-16 21:34:49 +0000614Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000615
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000616- A very subtle syntactical pitfall in list comprehensions was fixed.
617 For example: [a+b for a in 'abc', for b in 'def']. The comma in
618 this example is a mistake. Previously, this would silently let 'a'
619 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
620 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
621 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
622 Note that [a for a in <singleton>] is a convoluted way to say
623 [<singleton>] anyway, so it's not like any expressiveness is lost.
624
Guido van Rossum9074ef62001-10-16 21:34:49 +0000625- getattr(obj, name, default) now only catches AttributeError, as
626 documented, rather than returning the default value for all
627 exceptions (which could mask bugs in a __getattr__ hook, for
628 example).
629
Fred Drakecb7a6b52001-10-22 18:41:51 +0000630- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000631 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000632 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000633 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000634
Guido van Rossum1c486092001-10-19 02:05:35 +0000635- unicode(obj) now behaves more like str(obj), accepting arbitrary
636 objects, and calling a __unicode__ method if it exists.
637 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000638 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000639
Barry Warsawf6fb1712001-10-19 05:35:40 +0000640- isinstance() now allows any object as the first argument and a
641 class, a type or something with a __bases__ tuple attribute for the
642 second argument. The second argument may also be a tuple of a
643 class, type, or something with __bases__, in which case isinstance()
644 will return true if the first argument is an instance of any of the
645 things contained in the second argument tuple. E.g.
646
647 isinstance(x, (A, B))
648
649 returns true if x is an instance of A or B.
650
Guido van Rossum9074ef62001-10-16 21:34:49 +0000651Extension modules
652
653- thread.start_new_thread() now returns the thread ID (previously None).
654
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000655- binascii has now two quopri support functions, a2b_qp and b2a_qp.
656
Guido van Rossumc524d952001-10-19 01:31:59 +0000657- readline now supports setting the startup_hook and the
658 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000659
Guido van Rossumc524d952001-10-19 01:31:59 +0000660- os and posix supports chroot(), setgroups() and unsetenv() where
661 available. The stat(), fstat(), statvfs() and fstatvfs() functions
662 now return "pseudo-sequences" -- the various fields can now be
663 accessed as attributes (e.g. os.stat("/").st_mtime) but for
664 backwards compatibility they also behave as a fixed-length sequence.
665 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000666 attributes.
667
668- time: localtime(), gmtime() and strptime() now return a
669 pseudo-sequence similar to the os.stat() return value, with
670 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000671
Guido van Rossum9074ef62001-10-16 21:34:49 +0000672- Decompression objects in the zlib module now accept an optional
673 second parameter to decompress() that specifies the maximum amount
674 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000675
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000676- optional SSL support in the socket module now exports OpenSSL
677 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
678 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000679 automatically seed its PRNG. Also, the keyfile and certfile
680 arguments to socket.ssl() are now optional.
681
682- posixmodule (and by extension, the os module on POSIX platforms) now
683 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000684
Guido van Rossum9074ef62001-10-16 21:34:49 +0000685Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000686
Tim Peters7402f792001-10-02 03:53:41 +0000687- doctest now excludes functions and classes not defined by the module
688 being tested, thanks to Tim Hochberg.
689
Fred Drakecb7a6b52001-10-22 18:41:51 +0000690- HotShot, a new profiler implemented using a C-based callback, has
691 been added. This substantially reduces the overhead of profiling,
692 but it is still quite preliminary. Support modules and
693 documentation will be added in upcoming releases (before 2.2 final).
694
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000695- profile now produces correct output in situations where an exception
696 raised in Python is cleared by C code (e.g. hasattr()). This used
697 to cause wrong output, including spurious claims of recursive
698 functions and attribution of time spent to the wrong function.
699
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000700 The code and documentation for the derived OldProfile and HotProfile
701 profiling classes was removed. The code hasn't worked for years (if
702 you tried to use them, they raised exceptions). OldProfile
703 intended to reproduce the behavior of the profiler Python used more
704 than 7 years ago, and isn't interesting anymore. HotProfile intended
705 to provide a faster profiler (but producing less information), and
706 that's a worthy goal we intend to meet via a different approach (but
707 without losing information).
708
Tim Peterscce092d2001-10-09 05:31:56 +0000709- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000710 a much better system-specific calibration constant. The constant can
711 now be specified in an instance constructor, or as a Profile class or
712 instance variable, instead of by editing profile.py's source code.
713 Calibration must still be done manually (see the docs for the profile
714 module).
715
716 Note that Profile.calibrate() must be overriden by subclasses.
717 Improving the accuracy required exploiting detailed knowledge of
718 profiler internals; the earlier method abstracted away the details
719 and measured a simplified model instead, but consequently computed
720 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000721
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000722- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000723 which indicates whether output is intended for the header 'Q'
724 encoding.
725
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000726- The SocketServer.ThreadingMixIn class now closes the request after
727 finish_request() returns. (Not when it errors out though.)
728
Barry Warsawf6fb1712001-10-19 05:35:40 +0000729- The nntplib module's NNTP.body() method has grown a `file' argument
730 to allow saving the message body to a file.
731
732- The email package has added a class email.Parser.HeaderParser which
733 only parses headers and does not recurse into the message's body.
734 Also, the module/class MIMEAudio has been added for representing
735 audio data (contributed by Anthony Baxter).
736
737- ftplib should be able to handle files > 2GB.
738
739- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
740 ON, and OFF.
741
Fred Drakecb7a6b52001-10-22 18:41:51 +0000742- xml.dom.minidom NodeList objects now support the length attribute
743 and item() method as required by the DOM specifications.
744
Guido van Rossumed554f62001-10-02 23:15:37 +0000745Tools/Demos
746
747- Demo/dns was removed. It no longer serves any purpose; a package
748 derived from it is now maintained by Anthony Baxter, see
749 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000750
Barry Warsawf6fb1712001-10-19 05:35:40 +0000751- The freeze tool has been made more robust, and two new options have
752 been added: -X and -E.
753
Tim Petersabf925f2001-09-28 21:53:42 +0000754Build
755
Barry Warsawf6fb1712001-10-19 05:35:40 +0000756- configure will use CXX in LINKCC if CXX is used to build main() and
757 the system requires to link a C++ main using the C++ compiler.
758
Tim Petersabf925f2001-09-28 21:53:42 +0000759C API
760
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000761- The documentation for the tp_compare slot is updated to require that
762 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
763 not correct. This is not yet enforced but will be enforced in
764 Python 2.3; even later, we may use -2 to indicate errors and +2 for
765 "NotImplemented". Right now, -1 should be used for an error return.
766
Tim Petersd38b1c72001-09-30 05:09:37 +0000767- PyLong_AsLongLong() now accepts int (as well as long) arguments.
768 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
769 as long) arguments.
770
Guido van Rossum3c288632001-10-16 21:13:49 +0000771- PyThread_start_new_thread() now returns a long int giving the thread
772 ID, if one can be calculated; it returns -1 for error, 0 if no
773 thread ID is calculated (this is an incompatible change, but only
774 the thread module used this API). This code has only really been
775 tested on Linux and Windows; other platforms please beware (and
776 report any bugs or strange behavior).
777
Guido van Rossum1c486092001-10-19 02:05:35 +0000778- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
779 input.
780
Tim Petersabf925f2001-09-28 21:53:42 +0000781New platforms
782
783Tests
784
785Windows
786
Tim Peters04cf1d32001-10-09 22:39:40 +0000787- Installer: If you install IDLE, and don't disable file-extension
788 registration, a new "Edit with IDLE" context (right-click) menu entry
789 is created for .py and .pyw files.
790
Tim Peters1ce3cf72001-10-01 17:58:40 +0000791- The signal module now supports SIGBREAK on Windows, thanks to Steven
792 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
793 action remains to call Win32 ExitProcess(). This can be changed via
794 signal.signal(). For example:
795
796 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
797 # (SIGINT) behavior.
798 import signal
799 signal.signal(signal.SIGBREAK,
800 signal.default_int_handler)
801
802 try:
803 while 1:
804 pass
805 except KeyboardInterrupt:
806 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
807 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
808 # program without the possibility for any Python-level cleanup).
809 print "Clean exit"
810
Tim Petersabf925f2001-09-28 21:53:42 +0000811
Tim Petersb07352e2001-09-08 01:25:47 +0000812What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000813Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000814===========================
815
Guido van Rossum808eea72001-09-25 04:15:41 +0000816Type/class unification and new-style classes
817
818- pydoc and inspect are now aware of new-style classes;
819 e.g. help(list) at the interactive prompt now shows proper
820 documentation for all operations on list objects.
821
822- Applications using Jim Fulton's ExtensionClass module can now safely
823 be used with Python 2.2. In particular, Zope 2.4.1 now works with
824 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
825 examples also work again. It is hoped that Gtk and Boost also work
826 with 2.2a4 and beyond. (If you can confirm this, please write
827 webmaster@python.org; if there are still problems, please open a bug
828 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000829
Tim Peters66c1a522001-09-24 21:17:50 +0000830- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
831 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
832 in the constructed property object. fget, fset and fdel weren't
833 discoverable from Python in 2.2a3. __doc__ is new, and allows to
834 associate a docstring with a property.
835
Guido van Rossum808eea72001-09-25 04:15:41 +0000836- Comparison overloading is now more completely implemented. For
837 example, a str subclass instance can properly be compared to a str
838 instance, and it can properly overload comparison. Ditto for most
839 other built-in object types.
840
841- The repr() of new-style classes has changed; instead of <type
842 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
843 *except* for built-in types, which are still rendered as <type
844 'Foo'> (to avoid upsetting existing code that might parse or
845 otherwise rely on repr() of certain type objects).
846
847- The repr() of new-style objects is now always <Foo object at XXX>;
848 previously, it was sometimes <Foo instance at XXX>.
849
850- For new-style classes, what was previously called __getattr__ is now
851 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000852 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000853 one in classic classes is defined which is called only if regular
854 attribute access raises AttributeError; to catch *all* attribute
855 access, you can use __getattribute__ (for new-style classes). If
856 both are defined, __getattribute__ is called first, and if it raises
857 AttributeError, __getattr__ is called.
858
859- The __class__ attribute of new-style objects can be assigned to.
860 The new class must have the same C-level object layout as the old
861 class.
862
863- The builtin file type can be subclassed now. In the usual pattern,
864 "file" is the name of the builtin type, and file() is a new builtin
865 constructor, with the same signature as the builtin open() function.
866 file() is now the preferred way to open a file.
867
868- Previously, __new__ would only see sequential arguments passed to
869 the type in a constructor call; __init__ would see both sequential
870 and keyword arguments. This made no sense whatsoever any more, so
871 now both __new__ and __init__ see all arguments.
872
873- Previously, hash() applied to an instance of a subclass of str or
874 unicode always returned 0. This has been repaired.
875
876- Previously, an operation on an instance of a subclass of an
877 immutable type (int, long, float, complex, tuple, str, unicode),
878 where the subtype didn't override the operation (and so the
879 operation was handled by the builtin type), could return that
880 instance instead a value of the base type. For example, if s was of
881 a str sublass type, s[:] returned s as-is. Now it returns a str
882 with the same value as s.
883
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000884- Provisional support for pickling new-style objects has been added.
885
Guido van Rossum808eea72001-09-25 04:15:41 +0000886Core
887
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000888- file.writelines() now accepts any iterable object producing strings.
889
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000890- PyUnicode_FromEncodedObject() now works very much like
891 PyObject_Str(obj) in that it tries to use __str__/tp_str
892 on the object if the object is not a string or buffer. This
893 makes unicode() behave like str() when applied to non-string/buffer
894 objects.
895
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000896- PyFile_WriteObject now passes Unicode objects to the file's write
897 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000898 of a print statement must support Unicode objects, i.e. they must
899 at least convert them into ASCII strings.
900
Guido van Rossum624c8af2001-09-18 15:21:04 +0000901- Thread scheduling on Solaris should be improved; it is no longer
902 necessary to insert a small sleep at the start of a thread in order
903 to let other runnable threads be scheduled.
904
Tim Petersb07352e2001-09-08 01:25:47 +0000905Library
906
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000907- StringIO.StringIO instances and cStringIO.StringIO instances support
908 read character buffer compatible objects for their .write() methods.
909 These objects are converted to strings and then handled as such
910 by the instances.
911
Barry Warsaw2f600732001-09-24 04:28:10 +0000912- The "email" package has been added. This is basically a port of the
913 mimelib package <http://sf.net/projects/mimelib> with API changes
914 and some implementations updated to use iterators and generators.
915
Tim Peters8a9c2842001-09-22 21:30:22 +0000916- difflib.ndiff() and difflib.Differ.compare() are generators now. This
917 restores the ability of Tools/scripts/ndiff.py to start producing output
918 before the entire comparison is complete.
919
Barry Warsaw58b072d2001-09-22 04:44:21 +0000920- StringIO.StringIO instances and cStringIO.StringIO instances support
921 iteration just like file objects (i.e. their .readline() method is
922 called for each iteration until it returns an empty string).
923
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000924- The codecs module has grown four new helper APIs to access
925 builtin codecs: getencoder(), getdecoder(), getreader(),
926 getwriter().
927
Guido van Rossum624c8af2001-09-18 15:21:04 +0000928- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
929 simplifies writing XML RPC servers.
930
Barry Warsaw647d5e82001-09-28 17:01:02 +0000931- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000932 after interpretation of symbolic links. On non-Unix systems, this
933 is an alias for os.path.abspath().
934
Tim Peters16a77ad2001-09-08 04:00:12 +0000935- operator.indexOf() (PySequence_Index() in the C API) now works with any
936 iterable object.
937
Guido van Rossum624c8af2001-09-18 15:21:04 +0000938- smtplib now supports various authentication and security features of
939 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000940
Guido van Rossum624c8af2001-09-18 15:21:04 +0000941- hmac: a new module implementing keyed hashing for message
942 authentication.
943
944- mimetypes now recognizes more extensions and file types. At the
945 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000946
Guido van Rossum624c8af2001-09-18 15:21:04 +0000947- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000948 Python 2.2 bytecode generation. It has also been promoted from a
949 Tool to a standard library package. (Tools/compiler still exists as
950 a sample driver.)
951
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000952Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000953
Tim Petersb07352e2001-09-08 01:25:47 +0000954Build
955
Guido van Rossum624c8af2001-09-18 15:21:04 +0000956- Large file support (LFS) is now automatic when the platform supports
957 it; no more manual configuration tweaks are needed. On Linux, at
958 least, it's possible to have a system whose C library supports large
959 files but whose kernel doesn't; in this case, large file support is
960 still enabled but doesn't do you any good unless you upgrade your
961 kernel or share your Python executable with another system whose
962 kernel has large file support.
963
964- The configure script now supplies plausible defaults in a
965 cross-compilation environment. This doesn't mean that the supplied
966 values are always correct, or that cross-compilation now works
967 flawlessly -- but it's a first step (and it shuts up most of
968 autoconf's warnings about AC_TRY_RUN).
969
970- The Unix build is now a bit less chatty, courtesy of the parser
971 generator. The build is completely silent (except for errors) when
972 using "make -s", thanks to a -q option to setup.py.
973
Tim Petersb07352e2001-09-08 01:25:47 +0000974C API
975
Guido van Rossum624c8af2001-09-18 15:21:04 +0000976- The "structmember" API now supports some new flag bits to deny read
977 and/or write access to attributes in restricted execution mode.
978
Tim Petersb07352e2001-09-08 01:25:47 +0000979New platforms
980
Guido van Rossum624c8af2001-09-18 15:21:04 +0000981- Compaq's iPAQ handheld, running the "familiar" Linux distribution
982 (http://familiar.handhelds.org).
983
Tim Petersb07352e2001-09-08 01:25:47 +0000984Tests
985
Tim Peters8a9c2842001-09-22 21:30:22 +0000986- The "classic" standard tests, which work by comparing stdout to
987 an expected-output file under Lib/test/output/, no longer stop at
988 the first mismatch. Instead the test is run to completion, and a
989 variant of ndiff-style comparison is used to report all differences.
990 This is much easier to understand than the previous style of reporting.
991
992- The unittest-based standard tests now use regrtest's test_main()
993 convention, instead of running as a side-effect of merely being
994 imported. This allows these tests to be run in more natural and
995 flexible ways as unittests, outside the regrtest framework.
996
997- regrtest.py is much better integrated with unittest and doctest now,
998 especially in regard to reporting errors.
999
Tim Petersb07352e2001-09-08 01:25:47 +00001000Windows
1001
Guido van Rossum624c8af2001-09-18 15:21:04 +00001002- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001003 that support it (NTFS under Windows 2000). See "What's New in
1004 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001005
Tim Petersb07352e2001-09-08 01:25:47 +00001006
Tim Petersedc99312001-08-22 21:36:50 +00001007What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001008Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001009===========================
1010
1011Core
1012
Tim Peters9fffa3e2001-09-04 05:14:19 +00001013- Conversion of long to float now raises OverflowError if the long is too
1014 big to represent as a C double.
1015
Tim Peters32f453e2001-09-03 08:35:41 +00001016- The 3-argument builtin pow() no longer allows a third non-None argument
1017 if either of the first two arguments is a float, or if both are of
1018 integer types and the second argument is negative (in which latter case
1019 the arguments are converted to float, so this is really the same
1020 restriction).
1021
Tim Peters5d2b77c2001-09-03 05:47:38 +00001022- The builtin dir() now returns more information, and sometimes much
1023 more, generally naming all attributes of an object, and all attributes
1024 reachable from the object via its class, and from its class's base
1025 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1026 an empty list. In 2.2a3,
1027
1028 >>> dir([])
1029 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1030 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1031 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1032 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1033 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1034 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1035 'reverse', 'sort']
1036
1037 dir(module) continues to return only the module's attributes, though.
1038
Tim Petersbdee63f2001-09-02 03:40:59 +00001039- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001040 than raising OverflowError. This is a partial implementation of PEP
1041 237. You can use -Wdefault::OverflowWarning to enable a warning for
1042 this situation, and -Werror::OverflowWarning to revert to the old
1043 OverflowError exception.
1044
Guido van Rossum61c345f2001-09-04 03:26:15 +00001045- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001046 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001047 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1048 -Qold, meaning the / operator has its classic meaning and no
1049 warnings are issued. Using -Qwarn issues a run-time warning about
1050 all uses of classic division for int and long arguments; -Qwarnall
1051 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001052 (for use with fixdiv.py).
1053 [Note: the remainder of this paragraph (preserved below) became
1054 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1055 <obsolete>
1056 Using -Qnew is questionable; it turns on new division by default, but
1057 only in the __main__ module. You can usefully combine -Qwarn or
1058 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1059 warns about classic division everywhere else.
1060 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001061
Tim Petersbdee63f2001-09-02 03:40:59 +00001062- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001063 long, float, str, unicode, and tuple. (The types complex, list and
1064 dictionary can also be subclassed; this was introduced earlier.)
1065 Note that restrictions apply when subclassing immutable built-in
1066 types: you can only affect the value of the instance by overloading
1067 __new__. You can add mutable attributes, and the subclass instances
1068 will have a __dict__ attribute, but you cannot change the "value"
1069 (as implemented by the base class) of an immutable subclass instance
1070 once it is created.
1071
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001072- The dictionary constructor now takes an optional argument, a
1073 mapping-like object, and initializes the dictionary from its
1074 (key, value) pairs.
1075
Tim Petersbdee63f2001-09-02 03:40:59 +00001076- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001077 "cooperative super calls" in a multiple inheritance setting. For an
1078 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1079
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001080- A new built-in type, property, has been added. This enables the
1081 creation of "properties". These are attributes implemented by
1082 getter and setter functions (or only one of these for read-only or
1083 write-only attributes), without the need to override __getattr__.
1084 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001085
Tim Petersbdee63f2001-09-02 03:40:59 +00001086- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001087 liberalized, to allow leading zeroes. Examples of literals now
1088 legal that were SyntaxErrors before:
1089
1090 00.0 0e3 0100j 07.5 00000000000000000008.
1091
Tim Petersbdee63f2001-09-02 03:40:59 +00001092- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001093 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1094
Tim Petersedc99312001-08-22 21:36:50 +00001095Library
1096
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001097- telnetlib includes symbolic names for the options, and support for
1098 setting an option negotiation callback.
1099
Tim Petersa40c7932001-09-05 22:36:56 +00001100- The new C standard no longer requires that math libraries set errno to
1101 ERANGE on overflow. For platform libraries that exploit this new
1102 freedom, Python's overflow-checking was wholly broken. A new overflow-
1103 checking scheme attempts to repair that, but may not be reliable on all
1104 platforms (C doesn't seem to provide anything both useful and portable
1105 in this area anymore).
1106
Martin v. Löwis44f86962001-09-05 13:44:54 +00001107- Asynchronous timeout actions are available through the new class
1108 threading.Timer.
1109
Tim Peters78526162001-09-05 00:53:45 +00001110- math.log and math.log10 now return sensible results for even huge
1111 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1112
Tim Petersbdee63f2001-09-02 03:40:59 +00001113- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001114 currently held. See the docs for the imp module.
1115
Tim Petersbdee63f2001-09-02 03:40:59 +00001116- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001117 dumps containing ints written on platforms where Python ints are 8 bytes.
1118 When read on a box where Python ints are 4 bytes, such values are
1119 converted to Python longs.
1120
Tim Petersbdee63f2001-09-02 03:40:59 +00001121- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001122 code objects is no longer allowed. This plugs a security hole.
1123
Steve Purcell6091cd62001-09-06 16:05:17 +00001124- unittest.TestResult instances no longer store references to tracebacks
1125 generated by test failures. This prevents unexpected dangling references
1126 to objects that should be garbage collected between tests.
1127
Tim Petersedc99312001-08-22 21:36:50 +00001128Tools
1129
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001130- Tools/scripts/fixdiv.py has been added which can be used to fix
1131 division operators as per PEP 238.
1132
Tim Petersedc99312001-08-22 21:36:50 +00001133Build
1134
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001135- If you are an adventurous person using Mac OS X you may want to look at
1136 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1137 application, which can be used for experimenting with Carbon or Cocoa.
1138 Discussion of this on pythonmac-sig, please.
1139
Tim Peters7eea37e2001-09-04 22:08:56 +00001140C API
1141
1142- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001143
Tim Peters9fffa3e2001-09-04 05:14:19 +00001144- Note that PyLong_AsDouble can fail! This has always been true, but no
1145 callers checked for it. It's more likely to fail now, because overflow
1146 errors are properly detected now. The proper way to check:
1147
1148 double x = PyLong_AsDouble(some_long_object);
1149 if (x == -1.0 && PyErr_Occurred()) {
1150 /* The conversion failed. */
1151 }
1152
Tim Petersbdee63f2001-09-02 03:40:59 +00001153- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001154 compile but will not participate in GC. To upgrade an extension
1155 module:
1156
1157 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001158
Neil Schemenauer4042c692001-08-30 15:38:01 +00001159 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1160 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001161
Neil Schemenauer4042c692001-08-30 15:38:01 +00001162 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1163 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001164
Neil Schemenauer4042c692001-08-30 15:38:01 +00001165 - remove PyGC_HEAD_SIZE from object size calculations
1166
1167 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1168
Tim Petersbdee63f2001-09-02 03:40:59 +00001169- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001170 These can be used safely to construct string objects from a
1171 sprintf-style format string (similar to the format string supported
1172 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001173
Tim Petersedc99312001-08-22 21:36:50 +00001174New platforms
1175
Tim Petersb7da0902001-09-02 23:01:43 +00001176- Stephen Hansen contributed patches sufficient to get a clean compile
1177 under Borland C (Windows), but he reports problems running it and ran
1178 out of time to complete the port. Volunteers? Expect a MemoryError
1179 when importing the types module; this is probably shallow, and
1180 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001181
Tim Petersedc99312001-08-22 21:36:50 +00001182Tests
1183
1184Windows
1185
Tim Peters6e13a562001-09-06 00:32:15 +00001186- Large file support is now enabled on Win32 platforms as well as on
1187 Win64. This means that, for example, you can use f.tell() and f.seek()
1188 to manipulate files larger than 2 gigabytes (provided you have enough
1189 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001190 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1191 filesize limit, and large file support makes no difference there.
1192 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1193 NTFS has no practical limit on file size, and files of any size can be
1194 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001195
Tim Petersbdee63f2001-09-02 03:40:59 +00001196- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001197 points to command.com (patch from Brian Quinlan).
1198
Tim Petersedc99312001-08-22 21:36:50 +00001199
Tim Peters20f51a72001-07-21 02:31:40 +00001200What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001201Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001202===========================
1203
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001204Build
1205
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001206- Tim Peters developed a brand new Windows installer using Wise 8.1,
1207 generously donated to us by Wise Solutions.
1208
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001209- configure supports a new option --enable-unicode, with the values
1210 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1211 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001212
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001213- A new configure option --enable-framework builds a Mac OS X framework,
1214 which "make frameworkinstall" will install. This provides a starting
1215 point for more mac-like functionality, join pythonmac-sig@python.org
1216 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001217
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001218- The NeXT platform is no longer supported.
1219
1220- The `new' module is now statically linked.
1221
Tim Peters0afb6092001-08-15 06:06:44 +00001222Tools
1223
1224- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001225 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001226 the module docstring for details.
1227
Tim Peters20f51a72001-07-21 02:31:40 +00001228Tests
1229
Tim Peters5e824c32001-08-12 22:25:01 +00001230- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001231 platforms, allowing to give clearer test result output. regrtest
1232 also has optional --use/-u switch to run normally disabled tests
1233 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001234
Tim Peters20f51a72001-07-21 02:31:40 +00001235- Several new tests in the standard test suite, with special thanks to
1236 Nick Mathewson.
1237
1238Core
1239
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001240- The floor division operator // has been added as outlined in PEP
1241 238. The / operator still provides classic division (and will until
1242 Python 3.0) unless "from __future__ import division" is included, in
1243 which case the / operator will provide true division. The operator
1244 module provides truediv() and floordiv() functions. Augmented
1245 assignment variants are included, as are the equivalent overloadable
1246 methods and C API methods. See the PEP for a full discussion:
1247 <http://python.sf.net/peps/pep-0238.html>
1248
Tim Peters6cd6a822001-08-17 22:11:27 +00001249- Future statements are now effective in simulated interactive shells
1250 (like IDLE). This should "just work" by magic, but read Michael
1251 Hudson's "Future statements in simulated shells" PEP 264 for full
1252 details: <http://python.sf.net/peps/pep-0264.html>.
1253
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001254- The type/class unification (PEP 252-253) was integrated into the
1255 trunk and is not so tentative any more (the exact specification of
1256 some features is still tentative). A lot of work has done on fixing
1257 bugs and adding robustness and features (performance still has to
1258 come a long way).
1259
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001260- Warnings about a mismatch in the Python API during extension import
1261 now use the Python warning framework (which makes it possible to
1262 write filters for these warnings).
1263
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001264- A function's __dict__ (aka func_dict) will now always be a
1265 dictionary. It used to be possible to delete it or set it to None,
1266 but now both actions raise TypeErrors. It is still legal to set it
1267 to a dictionary object. Getting func.__dict__ before any attributes
1268 have been assigned now returns an empty dictionary instead of None.
1269
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001270- A new command line option, -E, was added which disables the use of
1271 all environment variables, or at least those that are specifically
1272 significant to Python. Usually those have a name starting with
1273 "PYTHON". This was used to fix a problem where the tests fail if
1274 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1275 older distribution.
1276
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001277Library
1278
Tim Peters5e824c32001-08-12 22:25:01 +00001279- New class Differ and new functions ndiff() and restore() in difflib.py.
1280 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001281 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001282
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001283- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1284 value using the minimal quoting required for the value; more
1285 reliable than using xml.sax.saxutils.escape() for attribute values.
1286
1287- Readline completion support for cmd.Cmd was added.
1288
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001289- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1290
1291- Added function threading.BoundedSemaphore()
1292
1293- Added Ka-Ping Yee's cgitb.py module.
1294
1295- The `new' module now exposes the CO_xxx flags.
1296
Martin v. Löwis560da622001-11-24 09:24:51 +00001297- The gc module offers the get_referents function.
1298
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001299New platforms
1300
1301C API
1302
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001303- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1304 which provide a cross-platform implementations for the
1305 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1306 the standard sprintf() and vsprintf() C lib APIs, these versions
1307 apply bounds checking on the used buffer which enhances protection
1308 against buffer overruns.
1309
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001310- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001311 and extensions using different Unicode widths is rendered next to
1312 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001313 will result in an ImportError. Unicode extensions writers must make
1314 sure to check the Unicode width compatibility in their extensions by
1315 using at least one of the mangled Unicode APIs in the extension.
1316
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001317- Two new flags METH_NOARGS and METH_O are available in method definition
1318 tables to simplify implementation of methods with no arguments and a
1319 single untyped argument. Calling such methods is more efficient than
1320 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1321 deprecated.
1322
Tim Petersc1731372001-08-04 08:12:36 +00001323Windows
1324
1325- "import module" now compiles module.pyw if it exists and nothing else
1326 relevant is found.
1327
Tim Peters20f51a72001-07-21 02:31:40 +00001328
Guido van Rossum55a78992001-07-17 17:22:32 +00001329What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001330Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001331===========================
1332
1333Core
Tim Petersa814db52001-05-14 07:05:58 +00001334
Tim Peters6d6c1a32001-08-02 04:15:00 +00001335- TENTATIVELY, a large amount of code implementing much of what's
1336 described in PEP 252 (Making Types Look More Like Classes) and PEP
1337 253 (Subtyping Built-in Types) was added. This will be released
1338 with Python 2.2a1. Documentation will be provided separately
1339 through http://www.python.org/2.2/. The purpose of releasing this
1340 with Python 2.2a1 is to test backwards compatibility. It is
1341 possible, though not likely, that a decision is made not to release
1342 this code as part of 2.2 final, if any serious backwards
1343 incompapatibilities are found during alpha testing that cannot be
1344 repaired.
1345
Guido van Rossum55a78992001-07-17 17:22:32 +00001346- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001347 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001348 more 'yield' statements. See PEP 255. Since this adds a new
1349 keyword to the language, this feature must be enabled by including a
1350 future statement: "from __future__ import generators" (see PEP 236).
1351 Generators will become a standard feature in a future release
1352 (probably 2.3). Without this future statement, 'yield' remains an
1353 ordinary identifier, but a warning is issued each time it is used.
1354 (These warnings currently don't conform to the warnings framework of
1355 PEP 230; we intend to fix this in 2.2a2.)
1356
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001357- The UTF-16 codec was modified to be more RFC compliant. It will now
1358 only remove BOM characters at the start of the string and then
1359 only if running in native mode (UTF-16-LE and -BE won't remove a
1360 leading BMO character).
1361
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001362- Strings now have a new method .decode() to complement the already
1363 existing .encode() method. These two methods provide direct access
1364 to the corresponding decoders and encoders of the registered codecs.
1365
1366 To enhance the usability of the .encode() method, the special
1367 casing of Unicode object return values was dropped (Unicode objects
1368 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001369
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001370 Both methods will now return whatever the codec in charge of the
1371 requested encoding returns as object, e.g. Unicode codecs will
1372 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1373 will return u"äöü"). This enables codec writer to create codecs
1374 for various simple to use conversions.
1375
1376 New codecs were added to demonstrate these new features (the .encode()
1377 and .decode() columns indicate the type of the returned objects):
1378
1379 Name | .encode() | .decode() | Description
1380 ----------------------------------------------------------------------
1381 uu | string | string | UU codec (e.g. for email)
1382 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001383 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001384 zlib | string | string | zlib compression
1385 hex | string | string | 2-byte hex codec
1386 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1387
Mark Hammond2a0af792001-05-14 03:09:36 +00001388- Some operating systems now support the concept of a default Unicode
1389 encoding for file system operations. Notably, Windows supports 'mbcs'
1390 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001391 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001392 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001393
1394 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001395 functions that return filenames (such as os.listdir()) to return Python
1396 string objects pre-encoded using the default file system encoding for
1397 the platform. As this encoding is likely to be different from Python's
1398 default encoding, converting this name to a Unicode object before passing
1399 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001400 would attempt to use its default encoding (generally ASCII) rather than
1401 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001402
Tim Petersa814db52001-05-14 07:05:58 +00001403 In general, this change simply removes surprises when working with
1404 Unicode and the file system, making these operations work as you expect,
1405 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001406 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001407
Tim Peters61dff2b2001-05-08 15:43:37 +00001408- Float (and complex) literals in source code were evaluated to full
1409 precision only when running from a .py file; the same code loaded from a
1410 .pyc (or .pyo) file could suffer numeric differences starting at about the
1411 12th significant decimal digit. For example, on a machine with IEEE-754
1412 floating arithmetic,
1413
1414 x = 9007199254740992.0
1415 print long(x)
1416
1417 printed 9007199254740992 if run directly from .py, but 9007199254740000
1418 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1419 str(float) instead of repr(float) when building code objects. marshal
1420 now uses repr(float) instead, which should reproduce floats to full
1421 machine precision (assuming the platform C float<->string I/O conversion
1422 functions are of good quality).
1423
1424 This may cause floating-point results to change in some cases, and
1425 usually for the better, but may also cause numerically unstable
1426 algorithms to break.
1427
Tim Peters2f228e72001-05-13 00:19:31 +00001428- The implementation of dicts suffers fewer collisions, which has speed
1429 benefits. However, the order in which dict entries appear in dict.keys(),
1430 dict.values() and dict.items() may differ from previous releases for a
1431 given dict. Nothing is defined about this order, so no program should
1432 rely on it. Nevertheless, it's easy to write test cases that rely on the
1433 order by accident, typically because of printing the str() or repr() of a
1434 dict to an "expected results" file. See Lib/test/test_support.py's new
1435 sortdict(dict) function for a simple way to display a dict in sorted
1436 order.
1437
Tim Peters7a3bfc32001-06-12 01:22:22 +00001438- Many other small changes to dicts were made, resulting in faster
1439 operation along the most common code paths.
1440
Guido van Rossum10315822001-05-01 20:54:30 +00001441- Dictionary objects now support the "in" operator: "x in dict" means
1442 the same as dict.has_key(x).
1443
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001444- The update() method of dictionaries now accepts generic mapping
1445 objects. Specifically the argument object must support the .keys()
1446 and __getitem__() methods. This allows you to say, for example,
1447 {}.update(UserDict())
1448
Guido van Rossum10315822001-05-01 20:54:30 +00001449- Iterators were added; this is a generalized way of providing values
1450 to a for loop. See PEP 234. There's a new built-in function iter()
1451 to return an iterator. There's a new protocol to get the next value
1452 from an iterator using the next() method (in Python) or the
1453 tp_iternext slot (in C). There's a new protocol to get iterators
1454 using the __iter__() method (in Python) or the tp_iter slot (in C).
1455 Iterating (i.e. a for loop) over a dictionary generates its keys.
1456 Iterating over a file generates its lines.
1457
Tim Petersf553f892001-05-01 20:45:31 +00001458- The following functions were generalized to work nicely with iterator
1459 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001460 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001461 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1462 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001463 join() method of strings
1464 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001465 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1466 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001467 right-hand side of assignment statements with multiple targets, such as
1468 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001469
Tim Petersd85e1022001-05-11 21:51:48 +00001470- Accessing module attributes is significantly faster (for example,
1471 random.random or os.path or yourPythonModule.yourAttribute).
1472
Tim Peterse63415e2001-05-08 04:38:29 +00001473- Comparing dictionary objects via == and != is faster, and now works even
1474 if the keys and values don't support comparisons other than ==.
1475
Tim Peters95bf9392001-05-10 08:32:44 +00001476- Comparing dictionaries in ways other than == and != is slower: there were
1477 insecurities in the dict comparison implementation that could cause Python
1478 to crash if the element comparison routines for the dict keys and/or
1479 values mutated the dicts. Making the code bulletproof slowed it down.
1480
Tim Peterseb28ef22001-06-02 05:27:19 +00001481- Collisions in dicts are resolved via a new approach, which can help
1482 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001483 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001484 faster now. Thanks to Christian Tismer for pointing out the cause and
1485 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001486
Tim Peters52e155e2001-06-16 05:42:57 +00001487- repr() is much faster for large containers (dict, list, tuple).
1488
1489
Tim Petersa814db52001-05-14 07:05:58 +00001490Library
1491
Fred Drake960fdf92001-07-20 18:38:26 +00001492- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1493 were added to the string module. These a locale-indenpendent
1494 constants, unlike letters, lowercase, and uppercase. These are now
1495 use in appropriate locations in the standard library.
1496
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001497- The flags used in dlopen calls can now be configured using
1498 sys.setdlopenflags and queried using sys.getdlopenflags.
1499
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001500- Fredrik Lundh's xmlrpclib is now a standard library module. This
1501 provides full client-side XML-RPC support. In addition,
1502 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1503 one asyncore-based). Thanks to Eric Raymond for the documentation.
1504
Guido van Rossum643d3912001-07-05 14:46:25 +00001505- The xrange() object is simplified: it no longer supports slicing,
1506 repetition, comparisons, efficient 'in' checking, the tolist()
1507 method, or the start, stop and step attributes. See PEP 260.
1508
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001509- A new function fnmatch.filter to filter lists of file names was added.
1510
Barry Warsawffd674d2001-05-22 16:00:10 +00001511- calendar.py uses month and day names based on the current locale.
1512
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001513- strop is now *really* obsolete (this was announced before with 1.6),
1514 and issues DeprecationWarning when used (except for the four items
1515 that are still imported into string.py).
1516
Tim Petersa814db52001-05-14 07:05:58 +00001517- Cookie.py now sorts key+value pairs by key in output strings.
1518
1519- pprint.isrecursive(object) didn't correctly identify recursive objects.
1520 Now it does.
1521
Tim Peters95b3f782001-05-14 18:39:41 +00001522- pprint functions now much faster for large containers (tuple, list, dict).
1523
Tim Peters7b9542a2001-06-10 23:40:19 +00001524- New 'q' and 'Q' format codes in the struct module, corresponding to C
1525 types "long long" and "unsigned long long" (on Windows, __int64). In
1526 native mode, these can be used only when the platform C compiler supports
1527 these types (when HAVE_LONG_LONG is #define'd by the Python config
1528 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001529 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1530 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001531
Guido van Rossum83213cc2001-06-12 16:48:52 +00001532- The site module installs a new built-in function 'help' that invokes
1533 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1534 it displays a message reminding the user to use 'help()' or
1535 'help(object)'.
1536
Tim Petersa814db52001-05-14 07:05:58 +00001537Tests
1538
1539- New test_mutants.py runs dict comparisons where the key and value
1540 comparison operators mutute the dicts randomly during comparison. This
1541 rapidly causes Python to crash under earlier releases (not for the faint
1542 of heart: it can also cause Win9x to freeze or reboot!).
1543
1544- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001545 pprint.isreadable() return sensible results. Also verifies that simple
1546 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001547
Tim Peters4324aa32001-05-28 22:30:08 +00001548C API
1549
1550- Removed the unused last_is_sticky argument from the internal
1551 _PyTuple_Resize(). If this affects you, you were cheating.
1552
1553
Guido van Rossum55a78992001-07-17 17:22:32 +00001554======================================================================
1555
1556
Guido van Rossumffe13be2001-04-16 18:46:45 +00001557What's New in Python 2.1 (final)?
1558=================================
1559
1560We only changed a few things since the last release candidate, all in
1561Python library code:
1562
1563- A bug in the locale module was fixed that affected locales which
1564 define no grouping for numeric formatting.
1565
1566- A few bugs in the weakref module's implementations of weak
1567 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1568 and the test suite was updated to check for these bugs.
1569
1570- An old bug in the os.path.walk() function (introduced in Python
1571 2.0!) was fixed: a non-existent file would cause an exception
1572 instead of being ignored.
1573
1574- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1575 PyChecker.
1576
1577
Guido van Rossum5b08f132001-04-16 02:05:23 +00001578What's New in Python 2.1c2?
1579===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001580
Guido van Rossum5b08f132001-04-16 02:05:23 +00001581A flurry of small changes, and one showstopper fixed in the nick of
1582time made it necessary to release another release candidate. The list
1583here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001584
Guido van Rossum5b08f132001-04-16 02:05:23 +00001585Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001586
Guido van Rossum5b08f132001-04-16 02:05:23 +00001587- Tim discovered a nasty bug in the dictionary code, caused by
1588 PyDict_Next() calling dict_resize(), and the GC code's use of
1589 PyDict_Next() violating an assumption in dict_items(). This was
1590 fixed with considerable amounts of band-aid, but the net effect is a
1591 saner and more robust implementation.
1592
1593- Made a bunch of symbols static that were accidentally global.
1594
1595Build and Ports
1596
1597- The setup.py script didn't check for a new enough version of zlib
1598 (1.1.3 is needed). Now it does.
1599
1600- Changed "make clean" target to also remove shared libraries.
1601
1602- Added a more general warning about the SGI Irix optimizer to README.
1603
1604Library
1605
1606- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1607 omitted the slash between host and file.html.
1608
1609- The mailbox module's _Mailbox class contained a completely broken
1610 and undocumented seek() method. Ripped it out.
1611
1612- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1613 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1614
1615- Fixed a few last-minute bugs in unittest.
1616
1617Extensions
1618
1619- Reverted the patch to the OpenSSL code in socketmodule.c to support
1620 RAND_status() and the EGD, and the subsequent patch that tried to
1621 fix it for pre-0.9.5 versions; the problem with the patch is that on
1622 some systems it issues a warning whenever socket is imported, and
1623 that's unacceptable.
1624
1625Tests
1626
1627- Fixed the pickle tests to work with "import test.test_pickle".
1628
1629- Tweaked test_locale.py to actually run the test Windows.
1630
1631- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1632 not "wb" (which is not a valid mode at all).
1633
1634- Fix pstats browser crashes. Import readline if it exists to make
1635 the user interface nicer.
1636
1637- Add "import thread" to the top of test modules that import the
1638 threading module (test_asynchat and test_threadedtempfile). This
1639 prevents test failures caused by a broken threading module resulting
1640 from a previously caught failed import.
1641
1642- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1643 needed on some platforms (e.g. Solaris 8) when the tests are run
1644 twice in succession.
1645
1646- Skip rather than fail test_sunaudiodev if no audio device is found.
1647
1648
1649What's New in Python 2.1c1?
1650===========================
1651
1652This list was significantly updated when 2.1c2 was released; the 2.1c1
1653release didn't mention most changes that were actually part of 2.1c1:
1654
1655Legal
1656
1657- Copyright was assigned to the Python Software Foundation (PSF) and a
1658 PSF license (very similar to the CNRI license) was added.
1659
1660- The CNRI copyright notice was updated to include 2001.
1661
1662Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001663
Guido van Rossumc9932722001-04-12 02:31:27 +00001664- After a public outcry, assignment to __debug__ is no longer illegal;
1665 instead, a warning is issued. It will become illegal in 2.2.
1666
Guido van Rossum5b08f132001-04-16 02:05:23 +00001667- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1668 "%#x" now always prepends "0x", even if the value is zero.
1669
1670- Fixed some nits in the bytecode compiler.
1671
1672- Fixed core dumps when calling certain kinds of non-functions.
1673
1674- Fixed various core dumps caused by reference count bugs.
1675
1676Build and Ports
1677
1678- Use INSTALL_SCRIPT to install script files.
1679
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001680- New port: SCO Unixware 7, by Billy G. Allie.
1681
Guido van Rossum5b08f132001-04-16 02:05:23 +00001682- Updated RISCOS port.
1683
1684- Updated BeOS port and notes.
1685
1686- Various other porting problems resolved.
1687
1688Library
1689
1690- The TERMIOS and SOCKET modules are now truly obsolete and
1691 unnecessary. Their symbols are incorporated in the termios and
1692 socket modules.
1693
1694- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1695 better tests for pickling.
1696
1697- threading: make Condition.wait() robust against KeyboardInterrupt.
1698
1699- zipfile: add support to zipfile to support opening an archive
1700 represented by an open file rather than a file name. Fix bug where
1701 the archive was not properly closed. Fixed a bug in this bugfix
1702 where flush() was called for a read-only file.
1703
1704- imputil: added an uninstall() method to the ImportManager.
1705
1706- Canvas: fixed bugs in lower() and tkraise() methods.
1707
1708- SocketServer: API change (added overridable close_request() method)
1709 so that the TCP server can explicitly close the request.
1710
1711- pstats: Eric Raymond added a simple interactive statistics browser,
1712 invoked when the module is run as a script.
1713
1714- locale: fixed a problem in format().
1715
1716- webbrowser: made it work when the BROWSER environment variable has a
1717 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1718 KDE 2. Fixed some other nits.
1719
1720- unittest: changes to allow using a different exception than
1721 AssertionError, and added a few more function aliases. Some other
1722 small changes.
1723
1724- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1725
1726- asynchat: fixed a critical bug in asynchat that slipped through the
1727 2.1b2 release. Fixed another rare bug.
1728
1729- Fix some unqualified except: clauses (always a bad code example).
1730
1731XML
1732
1733- pyexpat: new API get_version_string().
1734
1735- Fixed some minidom bugs.
1736
1737Extensions
1738
1739- Fixed a core dump in _weakref. Removed the weakref.mapping()
1740 function (it adds nothing to the API).
1741
1742- Rationalized the use of header files in the readline module, to make
1743 it compile (albeit with some warnings) with the very recent readline
1744 4.2, without breaking for earlier versions.
1745
1746- Hopefully fixed a buffering problem in linuxaudiodev.
1747
1748- Attempted a fix to make the OpenSSL support in the socket module
1749 work again with pre-0.9.5 versions of OpenSSL.
1750
1751Tests
1752
1753- Added a test case for asynchat and asyncore.
1754
1755- Removed coupling between tests where one test failing could break
1756 another.
1757
1758Tools
1759
1760- Ping added an interactive help browser to pydoc, fixed some nits
1761 in the rest of the pydoc code, and added some features to his
1762 inspect module.
1763
1764- An updated python-mode.el version 4.1 which integrates Ken
1765 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1766 much nicer in XEmacs and Emacs. When stepping through your program
1767 with pdb, in either the shell window or the *Python* window, the
1768 source file and line will be tracked by an arrow. Very cool!
1769
1770- IDLE: syntax warnings in interactive mode are changed into errors.
1771
1772- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001773 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001774
1775- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001776
Barry Warsaw11e89c72001-04-11 20:37:57 +00001777
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001778What's New in Python 2.1 beta 2?
1779================================
1780
Guido van Rossum053ae352001-03-22 14:17:21 +00001781(Unlisted are many fixed bugs, more documentation, etc.)
1782
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001783Core language, builtins, and interpreter
1784
Guido van Rossum053ae352001-03-22 14:17:21 +00001785- The nested scopes work (enabled by "from __future__ import
1786 nested_scopes") is completed; in particular, the future now extends
1787 into code executed through exec, eval() and execfile(), and into the
1788 interactive interpreter.
1789
1790- When calling a base class method (e.g. BaseClass.__init__(self)),
1791 this is now allowed even if self is not strictly spoken a class
1792 instance (e.g. when using metaclasses or the Don Beaudry hook).
1793
1794- Slice objects are now comparable but not hashable; this prevents
1795 dict[:] from being accepted but meaningless.
1796
1797- Complex division is now calculated using less braindead algorithms.
1798 This doesn't change semantics except it's more likely to give useful
1799 results in extreme cases. Complex repr() now uses full precision
1800 like float repr().
1801
1802- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1803
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001804- It is illegal to assign to the name __debug__, which is set when the
1805 interpreter starts. It is effectively a compile-time constant.
1806
1807- A warning will be issued if a global statement for a variable
1808 follows a use or assignment of that variable.
1809
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001810Standard library
1811
Guido van Rossum053ae352001-03-22 14:17:21 +00001812- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1813 inspired by JUnit), is now part of the standard library. You now
1814 have a choice of two testing frameworks: unittest requires you to
1815 write testcases as separate code, doctest gathers them from
1816 docstrings. Both approaches have their advantages and
1817 disadvantages.
1818
1819- A new module Tix was added, which wraps the Tix extension library
1820 for Tk. With that module, it is not necessary to statically link
1821 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1822 require" command. See Demo/tix/.
1823
1824- tzparse.py is now obsolete.
1825
1826- In gzip.py, the seek() and tell() methods are removed -- they were
1827 non-functional anyway, and it's better if callers can test for their
1828 existence with hasattr().
1829
1830Python/C API
1831
1832- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1833 that's already in the dictionary during a PyDict_Next() iteration.
1834 This used to fail occasionally when a dictionary resize operation
1835 could be triggered that would rehash all the keys. All other
1836 modifications to the dictionary are still off-limits during a
1837 PyDict_Next() iteration!
1838
1839- New extended APIs related to passing compiler variables around.
1840
1841- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1842 implement isinstance() and issubclass().
1843
1844- Py_BuildValue() now has a "D" conversion to create a Python complex
1845 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001846
Fred Drake4e262a92001-03-22 18:26:47 +00001847- Extensions types which support weak references must now set the
1848 field allocated for the weak reference machinery to NULL themselves;
1849 this is done to avoid the cost of checking each object for having a
1850 weakly referencable type in PyObject_INIT(), since most types are
1851 not weakly referencable.
1852
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001853- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1854 free variables and cell variables to and from the frame's f_locals.
1855
1856- Variants of several functions defined in pythonrun.h have been added
1857 to support the nested_scopes future statement. The variants all end
1858 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1859 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1860 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001861 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001862
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001863Distutils
1864
1865- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1866 into the release tree.
1867
Tim Peters0e57abf2001-05-02 07:39:38 +00001868- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001869 (an uninstaller, more customization of the installer's display)
1870
1871- from Jack Jansen: added Mac-specific code to generate a dialog for
1872 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001873 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001874 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001875
1876- added 'platforms' and 'keywords' to the set of metadata that can be
1877 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001878
1879- applied patches from Jason Tishler to make the compiler class work with
1880 Cygwin.
1881
1882
Tim Peters2fe289a2001-03-01 22:19:38 +00001883What's New in Python 2.1 beta 1?
1884================================
Tim Petersd66595f2001-02-04 03:09:53 +00001885
1886Core language, builtins, and interpreter
1887
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001888- Following an outcry from the community about the amount of code
1889 broken by the nested scopes feature introduced in 2.1a2, we decided
1890 to make this feature optional, and to wait until Python 2.2 (or at
1891 least 6 months) to make it standard. The option can be enabled on a
1892 per-module basis by adding "from __future__ import nested_scopes" at
1893 the beginning of a module (before any other statements, but after
1894 comments and an optional docstring). See PEP 236 (Back to the
1895 __future__) for a description of the __future__ statement. PEP 227
1896 (Statically Nested Scopes) has been updated to reflect this change,
1897 and to clarify the semantics in a number of endcases.
1898
1899- The nested scopes code, when enabled, has been hardened, and most
1900 bugs and memory leaks in it have been fixed.
1901
1902- Compile-time warnings are now generated for a number of conditions
1903 that will break or change in meaning when nested scopes are enabled:
1904
1905 - Using "from...import *" or "exec" without in-clause in a function
1906 scope that also defines a lambda or nested function with one or
1907 more free (non-local) variables. The presence of the import* or
1908 bare exec makes it impossible for the compiler to determine the
1909 exact set of local variables in the outer scope, which makes it
1910 impossible to determine the bindings for free variables in the
1911 inner scope. To avoid the warning about import *, change it into
1912 an import of explicitly name object, or move the import* statement
1913 to the global scope; to avoid the warning about bare exec, use
1914 exec...in... (a good idea anyway -- there's a possibility that
1915 bare exec will be deprecated in the future).
1916
1917 - Use of a global variable in a nested scope with the same name as a
1918 local variable in a surrounding scope. This will change in
1919 meaning with nested scopes: the name in the inner scope will
1920 reference the variable in the outer scope rather than the global
1921 of the same name. To avoid the warning, either rename the outer
1922 variable, or use a global statement in the inner function.
1923
Neil Schemenauera35c6882001-02-27 04:45:05 +00001924- An optional object allocator has been included. This allocator is
1925 optimized for Python objects and should be faster and use less memory
1926 than the standard system allocator. It is not enabled by default
1927 because of possible thread safety problems. The allocator is only
1928 protected by the Python interpreter lock and it is possible that some
1929 extension modules require a thread safe allocator. The object
1930 allocator can be enabled by providing the "--with-pymalloc" option to
1931 configure.
1932
Tim Petersd66595f2001-02-04 03:09:53 +00001933Standard library
1934
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001935- pyexpat now detects the expat version if expat.h defines it. A
1936 number of additional handlers are provided, which are only available
1937 since expat 1.95. In addition, the methods SetParamEntityParsing and
1938 GetInputContext of Parser objects are available with 1.95.x
1939 only. Parser objects now provide the ordered_attributes and
1940 specified_attributes attributes. A new module expat.model was added,
1941 which offers a number of additional constants if 1.95.x is used.
1942
1943- xml.dom offers the new functions registerDOMImplementation and
1944 getDOMImplementation.
1945
1946- xml.dom.minidom offers a toprettyxml method. A number of DOM
1947 conformance issues have been resolved. In particular, Element now
1948 has an hasAttributes method, and the handling of namespaces was
1949 improved.
1950
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001951- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1952 getting information about live Python code, and pydoc.py, a module
1953 for interactively converting docstrings to HTML or text.
1954 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001955 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001956 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1957 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001958
Tim Peters1eff7962001-03-01 02:31:33 +00001959- New library module difflib.py, primarily packaging the SequenceMatcher
1960 class at the heart of the popular ndiff.py file-comparison tool.
1961
1962- doctest.py (a framework for verifying Python code examples in docstrings)
1963 is now part of the std library.
1964
Tim Petersd66595f2001-02-04 03:09:53 +00001965Windows changes
1966
Guido van Rossume3955a82001-03-02 14:05:59 +00001967- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1968 small GUI that lets you browse the module docstrings using your
1969 default web browser.
1970
Tim Peters1eff7962001-03-01 02:31:33 +00001971- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1972 Platforms) is implemented. See
1973
1974 http://python.sourceforge.net/peps/pep-0235.html
1975
1976 for full details, especially the "Current Lower-Left Semantics" section.
1977 The new Windows import rules are simpler than before:
1978
1979 A. If the PYTHONCASEOK environment variable exists, same as
1980 before: silently accept the first case-insensitive match of any
1981 kind; raise ImportError if none found.
1982
1983 B. Else search sys.path for the first case-sensitive match; raise
1984 ImportError if none found.
1985
1986 The same rules have been implented on other platforms with case-
1987 insensitive but case-preserving filesystems too (including Cygwin, and
1988 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001989
Tim Peters25a9ce32001-02-19 07:06:36 +00001990- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1991 what it's supposed to do (and does do under NT and 2000) via direct
1992 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001993 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001994 all Win9x systems before.
1995
Tim Peters1eff7962001-03-01 02:31:33 +00001996- Build: Subproject _test (effectively) renamed to _testcapi.
1997
Tim Peters2fe289a2001-03-01 22:19:38 +00001998New platforms
1999
2000- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2001 Thanks to Steven Majewski!
2002
2003- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2004 Tishler!
2005
Guido van Rossum9089b272001-03-02 06:49:50 +00002006- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2007 Schwertberger! See RISCOS/README for more information -- it seems
2008 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002009 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002010
Tim Peters25a9ce32001-02-19 07:06:36 +00002011
Tim Petersd7b5e882001-01-25 03:36:26 +00002012What's New in Python 2.1 alpha 2?
2013=================================
Tim Peters40ead762001-01-27 05:35:26 +00002014
Tim Petersd7b5e882001-01-25 03:36:26 +00002015Core language, builtins, and interpreter
2016
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002017- Scopes nest. If a name is used in a function or class, but is not
2018 local, the definition in the nearest enclosing function scope will
2019 be used. One consequence of this change is that lambda statements
2020 could reference variables in the namespaces where the lambda is
2021 defined. In some unusual cases, this change will break code.
2022
2023 In all previous version of Python, names were resolved in exactly
2024 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002025 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002026 function A is defined within a function B, the names bound in B are
2027 not visible in A. The new rules make names bound in B visible in A,
2028 unless A contains a name binding that hides the binding in B.
2029
2030 Section 4.1 of the reference manual describes the new scoping rules
2031 in detail. The test script in Lib/test/test_scope.py demonstrates
2032 some of the effects of the change.
2033
2034 The new rules will cause existing code to break if it defines nested
2035 functions where an outer function has local variables with the same
2036 name as globals or builtins used by the inner function. Example:
2037
2038 def munge(str):
2039 def helper(x):
2040 return str(x)
2041 if type(str) != type(''):
2042 str = helper(str)
2043 return str.strip()
2044
2045 Under the old rules, the name str in helper() is bound to the
2046 builtin function str(). Under the new rules, it will be bound to
2047 the argument named str and an error will occur when helper() is
2048 called.
2049
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002050- The compiler will report a SyntaxError if "from ... import *" occurs
2051 in a function or class scope. The language reference has documented
2052 that this case is illegal, but the compiler never checked for it.
2053 The recent introduction of nested scope makes the meaning of this
2054 form of name binding ambiguous. In a future release, the compiler
2055 may allow this form when there is no possibility of ambiguity.
2056
Tim Peters40ead762001-01-27 05:35:26 +00002057- repr(string) is easier to read, now using hex escapes instead of octal,
2058 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2059
2060 >>> "\texample \r\n" + chr(0) + chr(255)
2061 '\texample \r\n\x00\xff' # in 2.1
2062 '\011example \015\012\000\377' # in 2.0
2063
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002064- Functions are now compared and hashed by identity, not by value, since
2065 the func_code attribute is writable.
2066
Fred Drakefb9d7122001-02-01 20:00:40 +00002067- Weak references (PEP 205) have been added. This involves a few
2068 changes in the core, an extension module (_weakref), and a Python
2069 module (weakref). The weakref module is the public interface. It
2070 includes support for "explicit" weak references, proxy objects, and
2071 mappings with weakly held values.
2072
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002073- A 'continue' statement can now appear in a try block within the body
2074 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002075 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002076
Tim Petersd7b5e882001-01-25 03:36:26 +00002077Standard library
2078
Barry Warsaw30dbd142001-01-31 22:14:01 +00002079- mailbox.py now has a new class, PortableUnixMailbox which is
2080 identical to UnixMailbox but uses a more portable scheme for
2081 determining From_ separators. Also, the constructors for all the
2082 classes in this module have a new optional `factory' argument, which
2083 is a callable used when new message classes must be instantiated by
2084 the next() method.
2085
Tim Petersd7b5e882001-01-25 03:36:26 +00002086- random.py is now self-contained, and offers all the functionality of
2087 the now-deprecated whrandom.py. See the docs for details. random.py
2088 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002089 and restoring the internal state of the generator; and jumpahead(n),
2090 for quickly forcing the internal state to be the same as if n calls to
2091 random() had been made. The latter is particularly useful for multi-
2092 threaded programs, creating one instance of the random.Random() class for
2093 each thread, then using .jumpahead() to force each instance to use a
2094 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002095
Tim Peters0de88fc2001-02-01 04:59:18 +00002096- random.py's seed() function is new. For bit-for-bit compatibility with
2097 prior releases, use the whseed function instead. The new seed function
2098 addresses two problems: (1) The old function couldn't produce more than
2099 about 2**24 distinct internal states; the new one about 2**45 (the best
2100 that can be done in the Wichmann-Hill generator). (2) The old function
2101 sometimes produced identical internal states when passed distinct
2102 integers, and there was no simple way to predict when that would happen;
2103 the new one guarantees to produce distinct internal states for all
2104 arguments in [0, 27814431486576L).
2105
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002106- The socket module now supports raw packets on Linux. The socket
2107 family is AF_PACKET.
2108
Tim Peters9ea17ac2001-02-02 05:57:15 +00002109- test_capi.py is a start at running tests of the Python C API. The tests
2110 are implemented by the new Modules/_testmodule.c.
2111
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002112- A new extension module, _symtable, provides provisional access to the
2113 internal symbol table used by the Python compiler. A higher-level
2114 interface will be added on top of _symtable in a future release.
2115
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002116- Removed the obsolete soundex module.
2117
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002118- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2119 the isSameNode method; NamedNodeMap the get method.
2120
2121- xml.sax.expatreader supports the lexical handler property; it
2122 generates comment, startCDATA, and endCDATA events.
2123
Tim Petersee826f82001-01-31 19:39:44 +00002124Windows changes
2125
2126- Build procedure: the zlib project is built in a different way that
2127 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002128 the zlib binary used. See PCbuild\readme.txt for details. Your old
2129 zlib-related directories can be deleted; you'll need to download fresh
2130 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002131
Tim Peters9ea17ac2001-02-02 05:57:15 +00002132- Build: New subproject _test for the benefit of test_capi.py (see above).
2133
Tim Petersb16c56f2001-02-02 21:24:51 +00002134- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2135 interface to some Python compiler internals).
2136
2137- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002138 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002139
Tim Petersa3a3a032000-11-30 05:22:44 +00002140What's New in Python 2.1 alpha 1?
2141=================================
2142
2143Core language, builtins, and interpreter
2144
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002145- There is a new Unicode companion to the PyObject_Str() API
2146 called PyObject_Unicode(). It behaves in the same way as the
2147 former, but assures that the returned value is an Unicode object
2148 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002149
Guido van Rossumf98eda02001-01-17 15:54:45 +00002150- The comparison operators support "rich comparison overloading" (PEP
2151 207). C extension types can provide a rich comparison function in
2152 the new tp_richcompare slot in the type object. The cmp() function
2153 and the C function PyObject_Compare() first try the new rich
2154 comparison operators before trying the old 3-way comparison. There
2155 is also a new C API PyObject_RichCompare() (which also falls back on
2156 the old 3-way comparison, but does not constrain the outcome of the
2157 rich comparison to a Boolean result).
2158
2159 The rich comparison function takes two objects (at least one of
2160 which is guaranteed to have the type that provided the function) and
2161 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2162 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2163 object, which may be NotImplemented (in which case the tp_compare
2164 slot function is used as a fallback, if defined).
2165
2166 Classes can overload individual comparison operators by defining one
2167 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002168 __ge__. There are no explicit "reflected argument" versions of
2169 these; instead, __lt__ and __gt__ are each other's reflection,
2170 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2171 reflection (similar at the C level). No other implications are
2172 made; in particular, Python does not assume that == is the Boolean
2173 inverse of !=, or that < is the Boolean inverse of >=. This makes
2174 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002175
2176 Classes or types that want to implement (in)equality tests but not
2177 the ordering operators (i.e. unordered types) should implement ==
2178 and !=, and raise an error for the ordering operators.
2179
Guido van Rossuma88479f2001-01-18 14:28:08 +00002180 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002181 Boolean; e.g. a matrix type might want to return a matrix of bits
2182 for A < B, giving elementwise comparisons. Such types should ensure
2183 that any interpretation of their value in a Boolean context raises
2184 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2185 at the C level) to always raise an exception.
2186
Guido van Rossuma88479f2001-01-18 14:28:08 +00002187- Complex numbers use rich comparisons to define == and != but raise
2188 an exception for <, <=, > and >=. Unfortunately, this also means
2189 that cmp() of two complex numbers raises an exception when the two
2190 numbers differ. Since it is not mathematically meaningful to compare
2191 complex numbers except for equality, I hope that this doesn't break
2192 too much code.
2193
Tim Peters3389f192001-02-18 08:48:49 +00002194- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002195 not defined by the language, other than that it's arbitrary but
2196 consistent (see the Reference Manual). An implementation detail changed
2197 in 2.1a1 such that None now compares less than any other object. Code
2198 relying on this new behavior (like code that relied on the previous
2199 behavior) does so at its own risk.
2200
Barry Warsaw573b5412001-01-15 20:43:18 +00002201- Functions and methods now support getting and setting arbitrarily
2202 named attributes (PEP 232). Functions have a new __dict__
2203 (a.k.a. func_dict) which hold the function attributes. Methods get
2204 and set attributes on their underlying im_func. It is a TypeError
2205 to set an attribute on a bound method.
2206
Guido van Rossum051e3352001-01-15 19:11:10 +00002207- The xrange() object implementation has been improved so that
2208 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2209 limitation that in this case len(xrange(sys.maxint)) can't be
2210 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2211 work fine as long as the index i doesn't actually reach 2**31.
2212 (Python uses regular ints for sequence and string indices; fixing
2213 that is much more work.)
2214
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002215- Two changes to from...import:
2216
Guido van Rossumba381232001-02-03 15:06:40 +00002217 1) "from M import X" now works even if (after loading module M)
2218 sys.modules['M'] is not a real module; it's basically a getattr()
2219 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002220
2221 2) "from M import *" now looks for M.__all__ to decide which names to
2222 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2223 filters out names starting with '_' as before. Whether or not
2224 __all__ exists, there's no restriction on the type of M.
2225
Guido van Rossumf61f1662001-01-10 20:13:55 +00002226- File objects have a new method, xreadlines(). This is the fastest
2227 way to iterate over all lines in a file:
2228
2229 for line in file.xreadlines():
2230 ...do something to line...
2231
2232 See the xreadlines module (mentioned below) for how to do this for
2233 other file-like objects.
2234
2235- Even if you don't use file.xreadlines(), you may expect a speedup on
2236 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002237 quite a bit in platform-specific ways: on systems (like Linux) that
2238 support flockfile(), getc_unlocked(), and funlockfile(), those are
2239 used by default. On systems (like Windows) without getc_unlocked(),
2240 a complicated (but still thread-safe) method using fgets() is used by
2241 default.
2242
Tim Petersd52269b2001-01-25 06:23:18 +00002243 You can force use of the fgets() method by #define'ing
2244 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002245 getc_unlocked()).
2246
Tim Petersd52269b2001-01-25 06:23:18 +00002247 You can force fgets() not to be used by #define'ing
2248 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002249 test_bufio.py fails -- and let us know if it does!).
2250
2251- In addition, the fileinput module, while still slower than the other
2252 methods on most platforms, has been sped up too, by using
2253 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002254
2255- Support for run-time warnings has been added, including a new
2256 command line option (-W) to specify the disposition of warnings.
2257 See the description of the warnings module below.
2258
2259- Extensive changes have been made to the coercion code. This mostly
2260 affects extension modules (which can now implement mixed-type
2261 numerical operators without having to use coercion), but
2262 occasionally, in boundary cases the coercion semantics have changed
2263 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002264 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002265 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002266 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002267
Guido van Rossumf98eda02001-01-17 15:54:45 +00002268- In connection with the coercion changes, a new built-in singleton
2269 object, NotImplemented is defined. This can be returned for
2270 operations that wish to indicate they are not implemented for a
2271 particular combination of arguments. From C, this is
2272 Py_NotImplemented.
2273
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002274- The interpreter accepts now bytecode files on the command line even
2275 if they do not have a .pyc or .pyo extension. On Linux, after executing
2276
Martin v. Löwise214baa2001-02-04 22:37:56 +00002277import imp,sys,string
2278magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2279reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2280open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002281
2282 any byte code file can be used as an executable (i.e. as an argument
2283 to execve(2)).
2284
Tim Peters9940b802000-12-01 07:59:35 +00002285- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002286 character. In 1.6 and earlier, they never produced a sign,
2287 and raised an error if the value of the long was too large
2288 to fit in a Python int. In 2.0, they produced a sign if and
2289 only if too large to fit in an int. This was inconsistent
2290 across platforms (because the size of an int varies across
2291 platforms), and inconsistent with hex() and oct(). Example:
2292
2293 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002294 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002295 'ffffffbe' # in 2.0 and before, on 32-bit machines
2296 >>> hex(-0x42L)
2297 '-0x42L' # in all versions of Python
2298
Tim Peters9940b802000-12-01 07:59:35 +00002299 The behavior of %d formats for negative Python longs remains
2300 the same as in 2.0 (although in 1.6 and before, they raised
2301 an error if the long didn't fit in a Python int).
2302
2303 %u formats don't make sense for Python longs, but are allowed
2304 and treated the same as %d in 2.1. In 2.0, a negative long
2305 formatted via %u produced a sign if and only if too large to
2306 fit in an int. In 1.6 and earlier, a negative long formatted
2307 via %u raised an error if it was too big to fit in an int.
2308
Guido van Rossum3661d392000-12-12 22:10:31 +00002309- Dictionary objects have an odd new method, popitem(). This removes
2310 an arbitrary item from the dictionary and returns it (in the form of
2311 a (key, value) pair). This can be useful for algorithms that use a
2312 dictionary as a bag of "to do" items and repeatedly need to pick one
2313 item. Such algorithms normally end up running in quadratic time;
2314 using popitem() they can usually be made to run in linear time.
2315
Tim Peters36cdad12000-12-29 02:06:45 +00002316Standard library
2317
Thomas Woutersfe385252001-01-19 23:16:56 +00002318- In the time module, the time argument to the functions strftime,
2319 localtime, gmtime, asctime and ctime is now optional, defaulting to
2320 the current time (in the local timezone).
2321
Guido van Rossumda91f222001-01-15 16:36:08 +00002322- The ftplib module now defaults to passive mode, which is deemed a
2323 more useful default given that clients are often inside firewalls
2324 these days. Note that this could break if ftplib is used to connect
2325 to a *server* that is inside a firewall, from outside; this is
2326 expected to be a very rare situation. To fix that, you can call
2327 ftp.set_pasv(0).
2328
Martin v. Löwis10a27872001-01-13 09:54:41 +00002329- The module site now treats .pth files not only for path configuration,
2330 but also supports extensions to the initialization code: Lines starting
2331 with import are executed.
2332
Guido van Rossumf61f1662001-01-10 20:13:55 +00002333- There's a new module, warnings, which implements a mechanism for
2334 issuing and filtering warnings. There are some new built-in
2335 exceptions that serve as warning categories, and a new command line
2336 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2337 turns warnings into errors). warnings.warn(message[, category])
2338 issues a warning message; this can also be called from C as
2339 PyErr_Warn(category, message).
2340
2341- A new module xreadlines was added. This exports a single factory
2342 function, xreadlines(). The intention is that this code is the
2343 absolutely fastest way to iterate over all lines in an open
2344 file(-like) object:
2345
2346 import xreadlines
2347 for line in xreadlines.xreadlines(file):
2348 ...do something to line...
2349
2350 This is equivalent to the previous the speed record holder using
2351 file.readlines(sizehint). Note that if file is a real file object
2352 (as opposed to a file-like object), this is equivalent:
2353
2354 for line in file.xreadlines():
2355 ...do something to line...
2356
Tim Peters36cdad12000-12-29 02:06:45 +00002357- The bisect module has new functions bisect_left, insort_left,
2358 bisect_right and insort_right. The old names bisect and insort
2359 are now aliases for bisect_right and insort_right. XXX_right
2360 and XXX_left methods differ in what happens when the new element
2361 compares equal to one or more elements already in the list: the
2362 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002363 right. Code that doesn't care where equal elements end up should
2364 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002365
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002366- The new curses.panel module wraps the panel library that forms part
2367 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2368
Guido van Rossumf61f1662001-01-10 20:13:55 +00002369- The SocketServer module now sets the allow_reuse_address flag by
2370 default in the TCPServer class.
2371
2372- A new function, sys._getframe(), returns the stack frame pointer of
2373 the caller. This is intended only as a building block for
2374 higher-level mechanisms such as string interpolation.
2375
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002376- The pyexpat module supports a number of new handlers, which are
2377 available only in expat 1.2. If invocation of a callback fails, it
2378 will report an additional frame in the traceback. Parser objects
2379 participate now in garbage collection. If expat reports an unknown
2380 encoding, pyexpat will try to use a Python codec; that works only
2381 for single-byte charsets. The parser type objects is exposed as
2382 XMLParserObject.
2383
2384- xml.dom now offers standard definitions for symbolic node type and
2385 exception code constants, and a hierarchy of DOM exceptions. minidom
2386 was adjusted to use them.
2387
2388- The conformance of xml.dom.minidom to the DOM specification was
2389 improved. It detects a number of additional error cases; the
2390 previous/next relationship works even when the tree is modified;
2391 Node supports the normalize() method; NamedNodeMap, DocumentType and
2392 DOMImplementation classes were added; Element supports the
2393 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2394 method.
2395
Guido van Rossumf61f1662001-01-10 20:13:55 +00002396Build issues
2397
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002398- For Unix (and Unix-compatible) builds, configuration and building of
2399 extension modules is now greatly automated. Rather than having to
2400 edit the Modules/Setup file to indicate which modules should be
2401 built and where their include files and libraries are, a
2402 distutils-based setup.py script now takes care of building most
2403 extension modules. All extension modules built this way are built
2404 as shared libraries. Only a few modules that must be linked
2405 statically are still listed in the Setup file; you won't need to
2406 edit their configuration.
2407
2408- Python should now build out of the box on Cygwin. If it doesn't,
2409 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002410
2411- Python now always uses its own (renamed) implementation of getopt()
2412 -- there's too much variation among C library getopt()
2413 implementations.
2414
2415- C++ compilers are better supported; the CXX macro is always set to a
2416 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002417
Tim Petersd92dfe02000-12-12 01:18:41 +00002418Windows changes
2419
2420- select module: By default under Windows, a select() call
2421 can specify no more than 64 sockets. Python now boosts
2422 this Microsoft default to 512. If you need even more than
2423 that, see the MS docs (you'll need to #define FD_SETSIZE
2424 and recompile Python from source).
2425
Guido van Rossumf61f1662001-01-10 20:13:55 +00002426- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2427 subdirectory is no more!
2428
Tim Petersa3a3a032000-11-30 05:22:44 +00002429
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002430What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002431=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002432
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002433Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002434changes are in the file HISTORY. If you are making the jump directly
2435from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2436HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002437
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002438Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2439the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2440http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002441
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002442--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002443
2444======================================================================
2445
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002446What's new in 2.0 (since release candidate 1)?
2447==============================================
2448
2449Standard library
2450
2451- The copy_reg module was modified to clarify its intended use: to
2452 register pickle support for extension types, not for classes.
2453 pickle() will raise a TypeError if it is passed a class.
2454
2455- Fixed a bug in gettext's "normalize and expand" code that prevented
2456 it from finding an existing .mo file.
2457
2458- Restored support for HTTP/0.9 servers in httplib.
2459
Tim Peters989b7b92000-10-16 20:24:53 +00002460- The math module was changed to stop raising OverflowError in case of
2461 underflow, and return 0 instead in underflow cases. Whether Python
2462 used to raise OverflowError in case of underflow was platform-
2463 dependent (it did when the platform math library set errno to ERANGE
2464 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002465
2466- Fixed a bug in StringIO that occurred when the file position was not
2467 at the end of the file and write() was called with enough data to
2468 extend past the end of the file.
2469
2470- Fixed a bug that caused Tkinter error messages to get lost on
2471 Windows. The bug was fixed by replacing direct use of
2472 interp->result with Tcl_GetStringResult(interp).
2473
2474- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2475 redirect response.
2476
2477- Several changes were made to distutils: Some debugging code was
2478 removed from util. Fixed the installer used when an external zip
2479 program (like WinZip) is not found; the source code for this
2480 installer is in Misc/distutils. check_lib() was modified to behave
2481 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2482 test for whether installed modules are on sys.path was changed to
2483 use both normcase() and normpath().
2484
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002485- Several minor bugs were fixed in the xml package (the minidom,
2486 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002487
2488- The regression test driver (regrtest.py) behavior when invoked with
2489 -l changed: It now reports a count of objects that are recognized as
2490 garbage but not freed by the garbage collector.
2491
Tim Peters989b7b92000-10-16 20:24:53 +00002492- The regression test for the math module was changed to test
2493 exceptional behavior when the test is run in verbose mode. Python
2494 cannot yet guarantee consistent exception behavior across platforms,
2495 so the exception part of test_math is run only in verbose mode, and
2496 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002497
2498Internals
2499
2500- PyOS_CheckStack() has been disabled on Win64, where it caused
2501 test_sre to fail.
2502
2503Build issues
2504
2505- Changed compiler flags, so that gcc is always invoked with -Wall and
2506 -Wstrict-prototypes. Users compiling Python with GCC should see
2507 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002508 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002509 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002510
Tim Petersa3a3a032000-11-30 05:22:44 +00002511- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002512
2513Tools and other miscellany
2514
2515- The compiler in Tools/compiler was updated to support the new
2516 language features introduced in 2.0: extended print statement, list
2517 comprehensions, and augmented assignments. The new compiler should
2518 also be backwards compatible with Python 1.5.2; the compiler will
2519 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002520 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002521
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002522What's new in 2.0 release candidate 1 (since beta 2)?
2523=====================================================
2524
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002525What is release candidate 1?
2526
2527We believe that release candidate 1 will fix all known bugs that we
2528intend to fix for the 2.0 final release. This release should be a bit
2529more stable than the previous betas. We would like to see even more
2530widespread testing before the final release, so we are producing this
2531release candidate. The final release will be exactly the same unless
2532any show-stopping (or brown bag) bugs are found by testers of the
2533release candidate.
2534
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002535All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002536to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002537
2538Core language, builtins, and interpreter
2539
2540- A bug that caused crashes when __coerce__ was used with augmented
2541 assignment, e.g. +=, was fixed.
2542
2543- Raise ZeroDivisionError when raising zero to a negative number,
2544 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2545 power operator and the result of math.pow(0.0, -2.0) will vary by
2546 platform. On Linux, it raises a ValueError.
2547
2548- A bug in Unicode string interpolation was fixed that occasionally
2549 caused errors with formats including "%%". For example, the
2550 following expression "%% %s" % u"abc" no longer raises a TypeError.
2551
2552- Compilation of deeply nested expressions raises MemoryError instead
2553 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2554
2555- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2556 rendering them useless. They are now written in binary mode again.
2557
2558Standard library
2559
2560- Keyword arguments are now accepted for most pattern and match object
2561 methods in SRE, the standard regular expression engine.
2562
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002563- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002564 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002565
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002566- Several bugs in the Unicode handling and error handling in _tkinter
2567 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002568
2569- Fix memory management errors in Merge() and Tkapp_Call() routines.
2570
2571- Several changes were made to cStringIO to make it compatible with
2572 the file-like object interface and with StringIO. If operations are
2573 performed on a closed object, an exception is raised. The truncate
2574 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002575 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002576
2577- There were many changes made to the linuxaudiodev module and its
2578 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002579 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002580
2581 Note that this module is named poorly, because it should work
2582 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002583 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002584
2585 The module now raises exceptions when errors occur instead of
2586 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2587 audio) and defines a getptr() method that calls the
2588 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2589
2590- The library_version attribute, introduced in an earlier beta, was
2591 removed because it can not be supported with early versions of the C
2592 readline library, which provides no way to determine the version at
2593 compile-time.
2594
2595- The binascii module is now enabled on Win64.
2596
Tim Peters46446d62000-10-09 21:19:31 +00002597- tokenize.py no longer suffers "recursion depth" errors when parsing
2598 programs with very long string literals.
2599
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002600Internals
2601
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002602- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002603 which is called when the interpreter starts up to determine where
2604 the standard library is installed. These vulnerabilities affect all
2605 previous versions of Python and can be exploited by setting very
2606 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2607 setuid Python script, although use of the wrapper in
2608 Misc/setuid-prog.c will eliminate the vulnerability.
2609
2610- Fixed garbage collection bugs in instance creation that were
2611 triggered when errors occurred during initialization. The solution,
2612 applied in cPickle and in PyInstance_New(), is to call
2613 PyObject_GC_Init() after the initialization of the object's
2614 container attributes is complete.
2615
2616- pyexpat adds definitions of PyModule_AddStringConstant and
2617 PyModule_AddObject if the Python version is less than 2.0, which
2618 provides compatibility with PyXML on Python 1.5.2.
2619
2620- If the platform has a bogus definition for LONG_BIT (the number of
2621 bits in a long), an error will be reported at compile time.
2622
2623- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2624 collection crashes and possibly other, unreported crashes.
2625
2626- Fixed a memory leak in _PyUnicode_Fini().
2627
2628Build issues
2629
2630- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002631 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002632 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002633
2634- The mmap.PAGESIZE constant is now initialized using sysconf when
2635 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2636
2637- The md5 file should now compile on all platforms.
2638
2639- The select module now compiles on platforms that do not define
2640 POLLRDNORM and related constants.
2641
2642- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002643 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002644
Jeremy Hylton10921202000-10-09 18:34:12 +00002645- BeOS: A number of changes were made to the build and installation
2646 process. ar-fake now operates on a directory of object files.
2647 dl_export.h is gone, and its macros now appear on the mwcc command
2648 line during build on PPC BeOS.
2649
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002650- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002651 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002652
2653- Cygwin: Support for shared libraries, Tkinter, and sockets.
2654
2655- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2656
2657Tools and other miscellany
2658
2659- Removed debugging prints from main used with freeze.
2660
Tim Peters46446d62000-10-09 21:19:31 +00002661- IDLE auto-indent no longer crashes when it encounters Unicode
2662 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002663
2664What's new in 2.0 beta 2 (since beta 1)?
2665========================================
2666
2667Core language, builtins, and interpreter
2668
Tim Peters482c0212000-09-26 06:33:09 +00002669- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002670 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002672- Add -h and -V command line options to print the usage message and
2673 Python version number and exit immediately.
2674
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002675- eval() and exec accept Unicode objects as code parameters.
2676
2677- getattr() and setattr() now also accept Unicode objects for the
2678 attribute name, which are converted to strings using the default
2679 encoding before lookup.
2680
2681- Multiplication on string and Unicode now does proper bounds
2682 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2683 string is too long."
2684
2685- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002686 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002687
Jeremy Hylton1b618592000-09-26 05:32:36 +00002688
2689Standard library and extensions
2690
Guido van Rossum5b08f132001-04-16 02:05:23 +00002691- socket module: the OpenSSL code now adds support for RAND_status()
2692 and EGD (Entropy Gathering Device).
2693
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002694- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002695 argument checking; it still takes no arguments.
2696
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002697- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002698
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002699- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002700
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002701- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002702
2703- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002704 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002705
2706- copy: Copy Unicode objects atomically.
2707
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002708- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002709
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002710- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002711
Fred Drake67233bc2000-09-26 16:40:27 +00002712- dbm: Add get() and setdefault() methods to dbm object. Add constant
2713 `library' to module that names the library used. Added doc strings
2714 and method names to error messages. Uses configure to determine
2715 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2716 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002717
2718- distutils: Update to version 0.9.3.
2719
2720- dl: Add several dl.RTLD_ constants.
2721
2722- fpectl: Now supported on FreeBSD.
2723
2724- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2725 found by the collector will be saved in gc.garbage. This is useful
2726 for debugging a program that creates reference cycles.
2727
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002728- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002729 of HTTP class. Do not close socket on zero-length response. Do not
2730 crash when server sends invalid content-length header.
2731
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002732- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002733
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002734- marshal: When reading a short, sign-extend on platforms where shorts
2735 are bigger than 16 bits. When reading a long, repair the unportable
2736 sign extension that was being done for 64-bit machines. (It assumed
2737 that signed right shift sign-extends.)
2738
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002739- operator: Add contains(), invert(), __invert__() as aliases for
2740 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002741
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002742- os: Add support for popen2() and popen3() on all platforms where
2743 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002744
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002745- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002746 clicking on a file in Explorer (or passing the file name to the
2747 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002748
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002749- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002750 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002751
2752- pickle: Now raises ValueError when an invalid pickle that contains
2753 a non-string repr where a string repr was expected. This behavior
2754 matches cPickle.
2755
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002756- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002757
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002758- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002759
2760- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002761 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002762 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002763
2764- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002765 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002766
2767- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002768 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002769 few cycles during startup since the first call to
2770 setdefaultencoding() will initialize the codec registry and the
2771 encodings package.
2772
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002773- socket: Support for size hint in readlines() method of object returned
2774 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002775
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002776- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002777 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002778 is followed by whitespace.
2779
Tim Petersa3a3a032000-11-30 05:22:44 +00002780- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002781
2782- struct: Check ranges for bytes and shorts.
2783
2784- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002785 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002786
2787- Tkinter: Image objects are now guaranteed to have unique ids. Set
2788 event.delta to zero if Tk version doesn't support mousewheel.
2789 Removed some debugging prints.
2790
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002791- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002792
Fred Drake67233bc2000-09-26 16:40:27 +00002793- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002794 which works around a bug in Norton AntiVirus 2000 that leads directly
2795 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002796
2797- xml: New version detection code allows PyXML to override standard
2798 XML package if PyXML version is greater than 0.6.1.
2799
Fred Drake64bb3802000-09-26 16:21:35 +00002800- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2801 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2802 tree only for nodes which are sufficiently interesting to a specific
2803 application. Does not provide the HTML-specific extensions. Still
2804 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002805
Fred Drake64bb3802000-09-26 16:21:35 +00002806- xml.sax: SAX 2 support for Python, including all the handler
2807 interfaces needed to process XML 1.0 compliant XML. Some
2808 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002809
Fred Drake64bb3802000-09-26 16:21:35 +00002810- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2811 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002812
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002813
Jeremy Hylton1b618592000-09-26 05:32:36 +00002814C API
2815
2816- Add three new convenience functions for module initialization --
2817 PyModule_AddObject(), PyModule_AddIntConstant(), and
2818 PyModule_AddStringConstant().
2819
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002820- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002821 removed and add #error to Python.h if NULL isn't defined after
2822 #include of stdio.h.
2823
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002824- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002825 backwards compatibility (at the source level) with old extensions.
2826
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002827- A wrapper API was added for signal() and sigaction(). Instead of
2828 either function, always use PyOS_getsig() to get a signal handler
2829 and PyOS_setsig() to set one. A new convenience typedef
2830 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002831
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002832- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002833 internal data buffer and size of a string object -- or the default
2834 encoded version of a Unicode object.
2835
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002836- PyString_Size() and PyString_AsString() accept Unicode objects.
2837
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002838- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002839 exists). INT_MAX and LONG_MAX will always be defined, even if
2840 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002841
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002842- PyFloat_FromString takes a second argument, pend, that was
2843 effectively useless. It is now officially useless but preserved for
2844 backwards compatibility. If the pend argument is not NULL, *pend is
2845 set to NULL.
2846
2847- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2848 for the attribute name. See note on getattr() above.
2849
2850- A few bug fixes to argument processing for Unicode.
2851 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2852 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2853 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002854 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002855
2856- Py_BuildValue accepts B format (for bgen-generated code).
2857
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002858
Jeremy Hylton1b618592000-09-26 05:32:36 +00002859Internals
2860
2861- On Unix, fix code for finding Python installation directory so that
2862 it works when argv[0] is a relative path.
2863
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002864- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002865 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002866 rather than by generating a copy of the object.
2867
Tim Peters482c0212000-09-26 06:33:09 +00002868- Several of the internal Unicode tables are much smaller now, and
2869 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002870
Jeremy Hylton97693b02000-09-26 17:42:51 +00002871- In the garbage collector: Fixed bug in collection of tuples. Fixed
2872 bug that caused some instances to be removed from the container set
2873 while they were still live. Fixed parsing in gc.set_debug() for
2874 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002875
2876- Fixed refcount problem in instance deallocation that only occurred
2877 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2878
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002879- On Windows, getpythonregpath is now protected against null data in
2880 registry key.
2881
2882- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002883 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002884
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002885
Jeremy Hylton1b618592000-09-26 05:32:36 +00002886Build and platform-specific issues
2887
2888- Better support of GNU Pth via --with-pth configure option.
2889
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002890- Python/C API now properly exposed to dynamically-loaded extension
2891 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002892
2893- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2894 Don't define MS_SYNC to be zero when it is undefined. Added missing
2895 prototypes in posixmodule.c.
2896
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002897- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002898 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002899
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002900- Fix largefile support on older NetBSD systems and OpenBSD by adding
2901 define for TELL64.
2902
2903
2904Tools and other miscellany
2905
2906- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2907
2908- freeze: The modulefinder now works with 2.0 opcodes.
2909
Tim Petersa3a3a032000-11-30 05:22:44 +00002910- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002911 Move hackery of sys.argv until after the Tk instance has been
2912 created, which allows the application-specific Tkinter
2913 initialization to be executed if present; also pass an explicit
2914 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002915
Jeremy Hylton1b618592000-09-26 05:32:36 +00002916
2917What's new in 2.0 beta 1?
2918=========================
2919
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002920Source Incompatibilities
2921------------------------
2922
2923None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2924such as single-argument append(), connect() and bind(), and changes to
2925str(long) and repr(float).
2926
2927
2928Binary Incompatibilities
2929------------------------
2930
2931- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2932with Python 2.0; these extensions will have to be rebuilt for Python
29332.0.
2934
2935- On Windows, attempting to import a third party extension built for
2936Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2937can do about this. Check your PYTHONPATH environment variable!
2938
2939- Python bytecode files (*.pyc and *.pyo) are not compatible between
2940releases.
2941
2942
2943Overview of Changes Since 1.6
2944-----------------------------
2945
2946There are many new modules (including brand new XML support through
2947the xml package, and i18n support through the gettext module); a list
2948of all new modules is included below. Lots of bugs have been fixed.
2949
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002950The process for making major new changes to the language has changed
2951since Python 1.6. Enhancements must now be documented by a Python
2952Enhancement Proposal (PEP) before they can be accepted.
2953
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002954There are several important syntax enhancements, described in more
2955detail below:
2956
2957 - Augmented assignment, e.g. x += 1
2958
2959 - List comprehensions, e.g. [x**2 for x in range(10)]
2960
2961 - Extended import statement, e.g. import Module as Name
2962
2963 - Extended print statement, e.g. print >> file, "Hello"
2964
2965Other important changes:
2966
2967 - Optional collection of cyclical garbage
2968
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002969Python Enhancement Proposal (PEP)
2970---------------------------------
2971
2972PEP stands for Python Enhancement Proposal. A PEP is a design
2973document providing information to the Python community, or describing
2974a new feature for Python. The PEP should provide a concise technical
2975specification of the feature and a rationale for the feature.
2976
2977We intend PEPs to be the primary mechanisms for proposing new
2978features, for collecting community input on an issue, and for
2979documenting the design decisions that have gone into Python. The PEP
2980author is responsible for building consensus within the community and
2981documenting dissenting opinions.
2982
2983The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002984
2985Augmented Assignment
2986--------------------
2987
2988This must have been the most-requested feature of the past years!
2989Eleven new assignment operators were added:
2990
Guido van Rossume905e952000-09-05 12:42:46 +00002991 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002992
2993For example,
2994
2995 A += B
2996
2997is similar to
2998
2999 A = A + B
3000
3001except that A is evaluated only once (relevant when A is something
3002like dict[index].attr).
3003
3004However, if A is a mutable object, A may be modified in place. Thus,
3005if A is a number or a string, A += B has the same effect as A = A+B
3006(except A is only evaluated once); but if a is a list, A += B has the
3007same effect as A.extend(B)!
3008
3009Classes and built-in object types can override the new operators in
3010order to implement the in-place behavior; the not-in-place behavior is
3011used automatically as a fallback when an object doesn't implement the
3012in-place behavior. For classes, the method name is derived from the
3013method name for the corresponding not-in-place operator by inserting
3014an 'i' in front of the name, e.g. __iadd__ implements in-place
3015__add__.
3016
3017Augmented assignment was implemented by Thomas Wouters.
3018
3019
3020List Comprehensions
3021-------------------
3022
3023This is a flexible new notation for lists whose elements are computed
3024from another list (or lists). The simplest form is:
3025
3026 [<expression> for <variable> in <sequence>]
3027
Guido van Rossum56db0952000-09-06 23:34:25 +00003028For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003029This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003030
3031You can also add a condition:
3032
3033 [<expression> for <variable> in <sequence> if <condition>]
3034
3035For example, [w for w in words if w == w.lower()] would yield the list
3036of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003037than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003038
3039You can also have nested for loops and more than one 'if' clause. For
3040example, here's a function that flattens a sequence of sequences::
3041
3042 def flatten(seq):
3043 return [x for subseq in seq for x in subseq]
3044
3045 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3046
3047This prints
3048
3049 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3050
3051List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003052Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003053
3054
3055Extended Import Statement
3056-------------------------
3057
3058Many people have asked for a way to import a module under a different
3059name. This can be accomplished like this:
3060
3061 import foo
3062 bar = foo
3063 del foo
3064
3065but this common idiom gets old quickly. A simple extension of the
3066import statement now allows this to be written as follows:
3067
3068 import foo as bar
3069
3070There's also a variant for 'from ... import':
3071
3072 from foo import bar as spam
3073
3074This also works with packages; e.g. you can write this:
3075
3076 import test.regrtest as regrtest
3077
3078Note that 'as' is not a new keyword -- it is recognized only in this
3079context (this is only possible because the syntax for the import
3080statement doesn't involve expressions).
3081
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003082Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003083
3084
3085Extended Print Statement
3086------------------------
3087
3088Easily the most controversial new feature, this extension to the print
3089statement adds an option to make the output go to a different file
3090than the default sys.stdout.
3091
3092For example, to write an error message to sys.stderr, you can now
3093write:
3094
3095 print >> sys.stderr, "Error: bad dog!"
3096
3097As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003098evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003099
3100 print >> None, "Hello world"
3101
3102is equivalent to
3103
3104 print "Hello world"
3105
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003106Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003107
3108
3109Optional Collection of Cyclical Garbage
3110---------------------------------------
3111
3112Python is now equipped with a garbage collector that can hunt down
3113cyclical references between Python objects. It's no replacement for
3114reference counting; in fact, it depends on the reference counts being
3115correct, and decides that a set of objects belong to a cycle if all
3116their reference counts can be accounted for from their references to
3117each other. This devious scheme was first proposed by Eric Tiedemann,
3118and brought to implementation by Neil Schemenauer.
3119
3120There's a module "gc" that lets you control some parameters of the
3121garbage collection. There's also an option to the configure script
3122that lets you enable or disable the garbage collection. In 2.0b1,
3123it's on by default, so that we (hopefully) can collect decent user
3124experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003125performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003126off by default in the final 2.0 release.
3127
3128
3129Smaller Changes
3130---------------
3131
3132A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3133map(None, seq1, seq2, ...) when the sequences have the same length;
3134i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3135the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003136zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003137
3138sys.version_info is a tuple (major, minor, micro, level, serial).
3139
3140Dictionaries have an odd new method, setdefault(key, default).
3141dict.setdefault(key, default) returns dict[key] if it exists; if not,
3142it sets dict[key] to default and returns that value. Thus:
3143
3144 dict.setdefault(key, []).append(item)
3145
3146does the same work as this common idiom:
3147
3148 if not dict.has_key(key):
3149 dict[key] = []
3150 dict[key].append(item)
3151
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003152There are two new variants of SyntaxError that are raised for
3153indentation-related errors: IndentationError and TabError.
3154
3155Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3156escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003157
3158The limits on the size of expressions and file in Python source code
3159have been raised from 2**16 to 2**32. Previous versions of Python
3160were limited because the maximum argument size the Python VM accepted
3161was 2**16. This limited the size of object constructor expressions,
3162e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3163limit was raised thanks to a patch by Charles Waldman that effectively
3164fixes the problem. It is now much more likely that you will be
3165limited by available memory than by an arbitrary limit in Python.
3166
3167The interpreter's maximum recursion depth can be modified by Python
3168programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3169limit is the maximum number of recursive calls that can be made by
3170Python code. The limit exists to prevent infinite recursion from
3171overflowing the C stack and causing a core dump. The default value is
31721000. The maximum safe value for a particular platform can be found
3173by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003174
3175New Modules and Packages
3176------------------------
3177
3178atexit - for registering functions to be called when Python exits.
3179
3180imputil - Greg Stein's alternative API for writing custom import
3181hooks.
3182
3183pyexpat - an interface to the Expat XML parser, contributed by Paul
3184Prescod.
3185
3186xml - a new package with XML support code organized (so far) in three
3187subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3188would fill a volume. There's a special feature whereby a
3189user-installed package named _xmlplus overrides the standard
3190xmlpackage; this is intended to give the XML SIG a hook to distribute
3191backwards-compatible updates to the standard xml package.
3192
3193webbrowser - a platform-independent API to launch a web browser.
3194
3195
Guido van Rossume905e952000-09-05 12:42:46 +00003196Changed Modules
3197---------------
3198
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003199array -- new methods for array objects: count, extend, index, pop, and
3200remove
3201
3202binascii -- new functions b2a_hex and a2b_hex that convert between
3203binary data and its hex representation
3204
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003205calendar -- Many new functions that support features including control
3206over which day of the week is the first day, returning strings instead
3207of printing them. Also new symbolic constants for days of week,
3208e.g. MONDAY, ..., SUNDAY.
3209
3210cgi -- FieldStorage objects have a getvalue method that works like a
3211dictionary's get method and returns the value attribute of the object.
3212
3213ConfigParser -- The parser object has new methods has_option,
3214remove_section, remove_option, set, and write. They allow the module
3215to be used for writing config files as well as reading them.
3216
3217ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003218optionally support the RFC 959 REST command.
3219
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003220gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003221
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003222httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3223the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003224
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003225locale -- implement getdefaultlocale for Win32 and Macintosh
3226
3227marshal -- no longer dumps core when marshaling deeply nested or
3228recursive data structures
3229
3230os -- new functions isatty, seteuid, setegid, setreuid, setregid
3231
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003232os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3233support under Unix.
3234
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003235os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003236
3237os.path -- fix semantics of os.path.commonprefix
3238
3239smtplib -- support for sending very long messages
3240
3241socket -- new function getfqdn()
3242
3243readline -- new functions to read, write and truncate history files.
3244The readline section of the library reference manual contains an
3245example.
3246
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003247select -- add interface to poll system call
3248
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003249shutil -- new copyfileobj function
3250
3251SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3252HTTP server.
3253
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003254Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003255
3256urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003257e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003258
3259whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003260
3261
3262Obsolete Modules
3263----------------
3264
3265None. However note that 1.6 made a whole slew of modules obsolete:
3266stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3267poly, zmod, strop, util, whatsound.
3268
3269
3270Changed, New, Obsolete Tools
3271----------------------------
3272
Tim Peters8b092332000-09-05 20:15:25 +00003273None.
Guido van Rossume905e952000-09-05 12:42:46 +00003274
3275
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003276C-level Changes
3277---------------
3278
3279Several cleanup jobs were carried out throughout the source code.
3280
3281All C code was converted to ANSI C; we got rid of all uses of the
3282Py_PROTO() macro, which makes the header files a lot more readable.
3283
3284Most of the portability hacks were moved to a new header file,
3285pyport.h; several other new header files were added and some old
3286header files were removed, in an attempt to create a more rational set
3287of header files. (Few of these ever need to be included explicitly;
3288they are all included by Python.h.)
3289
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003290Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003291and Win64, especially for the new Intel Itanium processor. Mick also
3292added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003293
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003294The C APIs to return an object's size have been update to consistently
3295use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3296previous versions, the abstract interfaces used PyXXX_Length and the
3297concrete interfaces used PyXXX_Size. The old names,
3298e.g. PyObject_Length, are still available for backwards compatibility
3299at the API level, but are deprecated.
3300
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003301The PyOS_CheckStack function has been implemented on Windows by
3302Fredrik Lundh. It prevents Python from failing with a stack overflow
3303on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003304
3305The GC changes resulted in creation of two new slots on object,
3306tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003307the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003308
3309The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003310C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003311
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003312PyErr_Format has been updated to automatically calculate the size of
3313the buffer needed to hold the formatted result string. This change
3314prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003315
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003316New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003317
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003318PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3319that are the same as their non-Ex counterparts except they take an
3320extra flag argument that tells them to close the file when done.
3321
3322XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003323
Tim Peters8b092332000-09-05 20:15:25 +00003324
3325Windows Changes
3326---------------
3327
3328New popen2/popen3/peopen4 in os module (see Changed Modules above).
3329
3330os.popen is much more usable on Windows 95 and 98. See Microsoft
3331Knowledge Base article Q150956. The Win9x workaround described there
3332is implemented by the new w9xpopen.exe helper in the root of your
3333Python installation. Note that Python uses this internally; it is not
3334a standalone program.
3335
3336Administrator privileges are no longer required to install Python
3337on Windows NT or Windows 2000. If you have administrator privileges,
3338Python's registry info will be written under HKEY_LOCAL_MACHINE.
3339Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003340under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003341uses of Python, but will prevent some advanced uses from working
3342(for example, running a Python script as an NT service, or possibly
3343from CGI).
3344
3345[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3346installer; instead, it installs the needed Tcl/Tk files directly in the
3347Python directory. If you already have a Tcl/Tk installation, this
3348wastes some disk space (about 4 Megs) but avoids problems with
3349conflicting Tcl/Tk installations, and makes it much easier for Python
3350to ensure that Tcl/Tk can find all its files.
3351
3352[This was new in 1.6] The Windows installer now installs by default in
3353\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3354
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003355
3356Updates to the changes between 1.5.2 and 1.6
3357--------------------------------------------
3358
3359The 1.6 NEWS file can't be changed after the release is done, so here
3360is some late-breaking news:
3361
3362New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3363and changes to getlocale() and setlocale().
3364
3365The new module is now enabled per default.
3366
3367It is not true that the encodings codecs cannot be used for normal
3368strings: the string.encode() (which is also present on 8-bit strings
3369!) allows using them for 8-bit strings too, e.g. to convert files from
3370cp1252 (Windows) to latin-1 or vice-versa.
3371
3372Japanese codecs are available from Tamito KAJIYAMA:
3373http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3374
3375
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003376======================================================================