blob: cd61d0ee62e7780eac9764906462ac5a285dbd88 [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. Löwis688357e2002-04-08 21:28:20 +000059- pwd, grp, and resource return enhanced tuples now, with symbolic
60 field names.
Martin v. Löwis29001ff2002-03-01 10:47:37 +000061
Martin v. Löwis99866332002-03-01 10:27:01 +000062- array.array is now a type object. A new format character
63 'u' indicates Py_UNICODE arrays. For those, .tounicode and
64 .fromunicode methods are available. Arrays now support __iadd__
65 and __imul__.
66
Neal Norwitze790eae2002-01-01 21:14:12 +000067- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000068 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
69 is called.
70
Tim Petersaf8446f2001-12-21 21:36:50 +000071Library
72
Marc-André Lemburg4179a012002-04-05 12:15:05 +000073- The UTF-16, -LE and -BE now raise a NotImplementedError
74 for all calls to .readline(). Previously, they used to just
75 produce garbage or fail with an encoding error -- UTF-16 is
76 a 2-byte encoding and the C lib's line reading APIs don't
77 work well with these.
78
Martin v. Löwis5c137c22002-03-18 12:44:08 +000079- compileall now supports quiet operation.
80
Martin v. Löwis587c98c2002-03-17 18:37:22 +000081- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
82 connections.
83
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000084- socket module: the SSL support was broken out of the main
85 _socket module C helper and placed into a new _ssl helper
86 which now gets imported by socket.py if available and working.
87
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000088- encodings package: added aliases for all supported IANA character
89 sets
90
Guido van Rossum606fe4e2001-12-28 20:57:14 +000091- ftplib: to safeguard the user's privacy, anonymous login will use
92 "anonymous@" as default password, rather than the real user and host
93 name.
94
Fred Drake36736122002-01-10 13:50:31 +000095- webbrowser: tightened up the command passed to os.system() so that
96 arbitrary shell code can't be executed because a bogus URL was
97 passed in.
98
Tim Peters11bd9942002-02-01 00:52:29 +000099- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +0000100 gettext.find an optional all argument. Translations will now fallback
101 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +0000102
Martin v. Löwis9668b932002-01-12 11:27:42 +0000103- distutils bdist commands now offer a --skip-build option.
104
Walter Dörwaldb25c2b02002-03-21 10:38:40 +0000105- warnings.warn now accepts a Warning instance as first argument.
106
Fred Drakefed7e852002-04-04 19:36:15 +0000107- The xml.sax.expatreader.ExpatParser class will no longer create
108 circular references by using itself as the locator that gets passed
109 to the content handler implementation. [SF bug #535474]
110
Tim Petersaf8446f2001-12-21 21:36:50 +0000111Tools/Demos
112
Marc-André Lemburg46260092002-04-04 16:17:11 +0000113- freeze.py now produces binaries which can import shared modules,
114 unlike before when this failed due to missing symbol exports in
115 the generated binary.
116
Tim Petersaf8446f2001-12-21 21:36:50 +0000117Build
118
Martin v. Löwis1142de32002-03-29 16:28:31 +0000119- On Unix, a shared libpython2.3.so can be created with --enable-shared.
120
Tim Peters8deda702002-03-30 10:06:07 +0000121- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
122 preprocessor symbols were eliminated. The internal decisions they
123 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000124
Tim Petersaf8446f2001-12-21 21:36:50 +0000125C API
126
Guido van Rossum0986d822002-04-08 01:38:42 +0000127- A type can now inherit its metatype from its base type. Previously,
128 when PyType_Ready() was called, if ob_type was found to be NULL, it
129 was always set to &PyType_Type; now it is set to base->ob_type,
130 where base is tp_base, defaulting to &PyObject_Type.
131
132- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
133
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000134- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
135 functions will be allocated using pymalloc if it is enabled. These
136 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
137 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
138 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
139 PyCore_* family of APIs have been removed.
140
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000141- The "u#" parser marker will now pass through Unicode object as-is
142 without going through the buffer API.
143
Martin v. Löwis7198a522002-01-01 19:59:11 +0000144- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
145
Tim Peters10a3bb52001-12-25 19:07:38 +0000146- An old #define of ANY as void has been removed from pyport.h. This
147 hasn't been used since Python's pre-ANSI days, and the #define has
148 been marked as obsolete since then. SF bug 495548 says it created
149 conflicts with other packages, so keeping it around wasn't harmless.
150
Tim Petersaf8446f2001-12-21 21:36:50 +0000151- Because Python's magic number scheme broke on January 1st, we decided
152 to stop Python development. Thanks for all the fish!
153
Tim Petersfb05db22002-03-11 00:24:00 +0000154- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000155 scheme to a new one. See Python/import.c for details.
156
Tim Petersaf8446f2001-12-21 21:36:50 +0000157New platforms
158
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000159- GNU/Hurd is now supported.
160
Tim Petersaf8446f2001-12-21 21:36:50 +0000161Tests
162
163Windows
164
Guido van Rossum181e41a2002-04-06 00:23:25 +0000165- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
166
Tim Peters33187922002-04-04 20:02:04 +0000167- The installer now installs Start menu shortcuts under (the local
168 equivalent of) "All Users" when doing an Admin install.
169
Tim Petersfb05db22002-03-11 00:24:00 +0000170- file.truncate([newsize]) now works on Windows for all newsize values.
171 It used to fail if newsize didn't fit in 32 bits, reflecting a
172 limitation of MS _chsize (which is no longer used).
173
Tim Petersab034fa2002-02-01 11:27:43 +0000174- os.waitpid() is now implemented for Windows, and can be used to block
175 until a specified process exits. This is similar to, but not exactly
176 the same as, os.waitpid() on POSIX systems. If you're waiting for
177 a specific process whose pid was obtained from one of the spawn()
178 functions, the same Python os.waitpid() code works across platforms.
Tim Peters33187922002-04-04 20:02:04 +0000179 See the docs for details. The docs were changed to clarify that
180 spawn functions return, and waitpid requires, a process handle on
181 Windows (not the same thing as a Windows process id).
Tim Petersab034fa2002-02-01 11:27:43 +0000182
Tim Peters11bd9942002-02-01 00:52:29 +0000183- New tempfile.TemporaryFile implementation for Windows: this doesn't
184 need a TemproraryFileWrapper wrapper anymore, and should be immune
185 to a nasty problem: before 2.3, if you got a temp file on Windows, it
186 got wrapped in an object whose close() method first closed the
187 underlying file, then deleted the file. This usually worked fine.
188 However, the spawn family of functions on Windows create (at a low C
189 level) the same set of open files in the spawned process Q as were
190 open in the spawning process P. If a temp file f was among them, then
191 doing f.close() in P first closed P's C-level file handle on f, but Q's
192 C-level file handle on f remained open, so the attempt in P to delete f
193 blew up with a "Permission denied" error (Windows doesn't allow
194 deleting open files). This was surprising, subtle, and difficult to
195 work around.
196
197- The os module now exports all the symbolic constants usable with the
198 low-level os.open() on Windows: the new constants in 2.3 are
199 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
200 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
201 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
202 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
203 (so specify both if you want both; note that neither is useful unless
204 specified with O_CREAT too).
205
Tim Petersaf8446f2001-12-21 21:36:50 +0000206Mac
207
208
Tim Peters909c0912001-12-14 23:16:18 +0000209What's New in Python 2.2 final?
210Release date: 21-Dec-2001
211===============================
212
213Type/class unification and new-style classes
214
Barry Warsaw52acb492001-12-21 20:04:22 +0000215- pickle.py, cPickle: allow pickling instances of new-style classes
216 with a custom metaclass.
217
Tim Peters909c0912001-12-14 23:16:18 +0000218Core and builtins
219
Barry Warsaw52acb492001-12-21 20:04:22 +0000220- weakref proxy object: when comparing, unwrap both arguments if both
221 are proxies.
222
Tim Peters909c0912001-12-14 23:16:18 +0000223Extension modules
224
Barry Warsaw52acb492001-12-21 20:04:22 +0000225- binascii.b2a_base64(): fix a potential buffer overrun when encoding
226 very short strings.
227
228- cPickle: the obscure "fast" mode was suspected of causing stack
229 overflows on the Mac. Hopefully fixed this by setting the recursion
230 limit much smaller. If the limit is too low (it only affects
231 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
232 when compiling cPickle.c (or in pyconfig.h).
233
Tim Peters909c0912001-12-14 23:16:18 +0000234Library
235
Barry Warsaw52acb492001-12-21 20:04:22 +0000236- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
237 close or delete time).
238
239- rfc822.py: fixed a bug where the address '<>' was converted to None
240 instead of an empty string (also fixes the email.Utils module).
241
242- xmlrpclib.py: version 1.0.0; uses precision for doubles.
243
244- test suite: the pickle and cPickle tests were not executing any code
245 when run from the standard regresssion test.
246
Tim Peters909c0912001-12-14 23:16:18 +0000247Tools/Demos
248
249Build
250
251C API
252
253New platforms
254
255Tests
256
257Windows
258
Barry Warsaw52acb492001-12-21 20:04:22 +0000259- distutils package: fixed broken Windows installers (bdist_wininst).
260
261- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
262 instances are deleted at process exit time.
263
264- socket.py: prevent mysterious warnings when socket instances are
265 deleted at process exit time.
266
267- posixmodule.c: fix a Windows crash with stat() of a filename ending
268 in backslash.
269
Tim Peters909c0912001-12-14 23:16:18 +0000270Mac
271
Barry Warsaw52acb492001-12-21 20:04:22 +0000272- The Carbon toolbox modules have been upgraded to Universal Headers
273 3.4, and experimental CoreGraphics and CarbonEvents modules have
274 been added. All only for framework-enabled MacOSX.
275
Tim Peters909c0912001-12-14 23:16:18 +0000276
Tim Peters6272dfd2001-12-13 19:34:00 +0000277What's New in Python 2.2c1?
278Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000279===========================
280
281Type/class unification and new-style classes
282
Barry Warsaw06557452001-12-14 20:47:12 +0000283- Guido's tutorial introduction to the new type/class features has
284 been extensively updated. See
285
286 http://www.python.org/2.2/descrintro.html
287
288 That remains the primary documentation in this area.
289
Guido van Rossum33bab012001-12-05 22:45:48 +0000290- Fixed a leak: instance variables declared with __slots__ were never
291 deleted!
292
Guido van Rossum4b800852001-12-03 00:54:52 +0000293- The "delete attribute" method of descriptor objects is called
294 __delete__, not __del__. In previous releases, it was mistakenly
295 called __del__, which created an unfortunate overloading condition
296 with finalizers. (The "get attribute" and "set attribute" methods
297 are still called __get__ and __set__, respectively.)
298
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000299- Some subtle issues with the super built-in were fixed:
300
301 (a) When super itself is subclassed, its __get__ method would still
302 return an instance of the base class (i.e., of super).
303
304 (b) super(C, C()).__class__ would return C rather than super. This
305 is confusing. To fix this, I decided to change the semantics of
306 super so that it only applies to code attributes, not to data
307 attributes. After all, overriding data attributes is not
308 supported anyway.
309
310 (c) The __get__ method didn't check whether the argument was an
311 instance of the type used in creation of the super instance.
312
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000313- Previously, hash() of an instance of a subclass of a mutable type
314 (list or dictionary) would return some value, rather than raising
315 TypeError. This has been fixed. Also, directly calling
316 dict.__hash__ and list.__hash__ now raises the same TypeError
317 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000318
Guido van Rossumd331cb52001-12-05 19:46:42 +0000319- New-style objects now support deleting their __dict__. This is for
320 all intents and purposes equivalent to assigning a brand new empty
321 dictionary, but saves space if the object is not used further.
322
Tim Petersb3c9af12001-11-17 00:21:57 +0000323Core and builtins
324
Tim Peters3caca232001-12-06 06:23:26 +0000325- -Qnew now works as documented in PEP 238: when -Qnew is passed on
326 the command line, all occurrences of "/" use true division instead
327 of classic division. See the PEP for details. Note that "all"
328 means all instances in library and 3rd-party modules, as well as in
329 your own code. As the PEP says, -Qnew is intended for use only in
330 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000331 Note that test_coercion.py in the standard Python test suite fails
332 under -Qnew; this is expected, and won't be repaired until true
333 division becomes the default (in the meantime, test_coercion is
334 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000335
Fred Drake6c01e252001-12-14 17:08:12 +0000336- complex() now only allows the first argument to be a string
337 argument, and raises TypeError if either the second arg is a string
338 or if the second arg is specified when the first is a string.
339
Tim Petersb3c9af12001-11-17 00:21:57 +0000340Extension modules
341
Martin v. Löwis560da622001-11-24 09:24:51 +0000342- gc.get_referents was renamed to gc.get_referrers.
343
Tim Petersb3c9af12001-11-17 00:21:57 +0000344Library
345
Tim Peters25059d32001-12-07 20:35:43 +0000346- Functions in the os.spawn() family now release the global interpreter
347 lock around calling the platform spawn. They should always have done
348 this, but did not before 2.2c1. Multithreaded programs calling
349 an os.spawn function with P_WAIT will no longer block all Python threads
350 until the spawned program completes. It's possible that some programs
351 relies on blocking, although more likely by accident than by design.
352
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000353- webbrowser defaults to netscape.exe on OS/2 now.
354
Martin v. Löwis652e1912001-11-25 14:50:56 +0000355- Tix.ResizeHandle exposes detach_widget, hide, and show.
356
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000357- The charset alias windows_1252 has been added.
358
Barry Warsaw06557452001-12-14 20:47:12 +0000359- types.StringTypes is a tuple containing the defined string types;
360 usually this will be (str, unicode), but if Python was compiled
361 without Unicode support it will be just (str,).
362
363- The pulldom and minidom modules were synchronized to PyXML.
364
Tim Petersb3c9af12001-11-17 00:21:57 +0000365Tools/Demos
366
Barry Warsaw06557452001-12-14 20:47:12 +0000367- A new script called Tools/scripts/google.py was added, which fires
368 off a search on Google.
369
Tim Petersb3c9af12001-11-17 00:21:57 +0000370Build
371
Barry Warsaw06557452001-12-14 20:47:12 +0000372- Note that release builds of Python should arrange to define the
373 preprocessor symbol NDEBUG on the command line (or equivalent).
374 In the 2.2 pre-release series we tried to define this by magic in
375 Python.h instead, but it proved to cause problems for extension
376 authors. The Unix, Windows and Mac builds now all define NDEBUG in
377 release builds via cmdline (or equivalent) instead. Ports to
378 other platforms should do likewise.
379
Jack Jansen1999ef42001-12-06 21:47:20 +0000380- It is no longer necessary to use --with-suffix when building on a
381 case-insensitive file system (such as Mac OS X HFS+). In the build
382 directory an extension is used, but not in the installed python.
383
Tim Petersb3c9af12001-11-17 00:21:57 +0000384C API
385
Tim Petersf582b822001-12-11 18:51:08 +0000386- New function PyDict_MergeFromSeq2() exposes the builtin dict
387 constructor's logic for updating a dictionary from an iterable object
388 producing key-value pairs.
389
Tim Peterscffed4b2001-11-29 03:26:37 +0000390- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000391 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000392 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
393 dump core in some bad cases. This has been repaired. As a result,
394 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
395 previously went unchallenged.
396
Tim Petersb3c9af12001-11-17 00:21:57 +0000397New platforms
398
399Tests
400
401Windows
402
403Mac
404
Jack Jansenffa260f2001-12-06 21:14:00 +0000405- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
406 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000407
Barry Warsaw06557452001-12-14 20:47:12 +0000408- Changed logic for finding python home in Mac OS X framework Pythons.
409 Now sys.executable points to the executable again, in stead of to
410 the shared library. The latter is used only for locating the python
411 home.
412
413
Tim Peters84362bc2001-10-19 17:55:30 +0000414What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000415Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000416===========================
417
418Type/class unification and new-style classes
419
Guido van Rossum3d27df02001-11-15 20:27:54 +0000420- Multiple inheritance mixing new-style and classic classes in the
421 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000422
423 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000424 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000425
426 The MRO (method resolution order) for each base class is respected
427 according to its kind, but the MRO for the derived class is computed
428 using new-style MRO rules if any base clase is a new-style class.
429 This needs to be documented.
430
Tim Petersa427a2b2001-10-29 22:25:45 +0000431- The new builtin dictionary() constructor, and dictionary type, have
432 been renamed to dict. This reflects a decade of common usage.
433
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000434- dict() now accepts an iterable object producing 2-sequences. For
435 example, dict(d.items()) == d for any dictionary d. The argument,
436 and the elements of the argument, can be any iterable objects.
437
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000438- New-style classes can now have a __del__ method, which is called
439 when the instance is deleted (just like for classic classes).
440
Guido van Rossum12d955c2001-10-26 14:56:06 +0000441- Assignment to object.__dict__ is now possible, for objects that are
442 instances of new-style classes that have a __dict__ (unless the base
443 class forbids it).
444
Guido van Rossumc8e56452001-10-22 00:43:43 +0000445- Methods of built-in types now properly check for keyword arguments
446 (formerly these were silently ignored). The only built-in methods
447 that take keyword arguments are __call__, __init__ and __new__.
448
Guido van Rossum86443212001-10-27 22:28:54 +0000449- The socket function has been converted to a type; see below.
450
Tim Peters84362bc2001-10-19 17:55:30 +0000451Core and builtins
452
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000453- Assignment to __debug__ raises SyntaxError at compile-time. This
454 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000455 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000456
Guido van Rossum12d955c2001-10-26 14:56:06 +0000457- Clarified the error messages for unsupported operands to an operator
458 (like 1 + '').
459
Tim Peters84362bc2001-10-19 17:55:30 +0000460Extension modules
461
Tim Peters5ebfd362001-11-13 23:11:19 +0000462- mmap has a new keyword argument, "access", allowing a uniform way for
463 both Windows and Unix users to create read-only, write-through and
464 copy-on-write memory mappings. This was previously possible only on
465 Unix. A new keyword argument was required to support this in a
466 uniform way because the mmap() signuatures had diverged across
467 platforms. Thanks to Jay T Miller for repairing this!
468
Tim Peters169ded02001-11-03 19:57:21 +0000469- By default, the gc.garbage list now contains only those instances in
470 unreachable cycles that have __del__ methods; in 2.1 it contained all
471 instances in unreachable cycles. "Instances" here has been generalized
472 to include instances of both new-style and old-style classes.
473
Guido van Rossum12d955c2001-10-26 14:56:06 +0000474- The socket module defines a new method for socket objects,
475 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000476 send() until all data has been sent. Also, the socket function has
477 been converted to a subclassable type, like list and tuple (etc.)
478 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000479
480- Various bugfixes to the curses module. There is now a test suite
481 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000482
Guido van Rossum692adf12001-10-30 03:03:03 +0000483- binascii.b2a_base64 no longer places an arbitrary restriction of 57
484 bytes on its input.
485
Tim Peters84362bc2001-10-19 17:55:30 +0000486Library
487
Tim Peters5ebfd362001-11-13 23:11:19 +0000488- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000489 convenience function.
490
Tim Peters75335872001-11-03 19:35:43 +0000491- Symbolic group names in regular expressions must be unique. For
492 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
493 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000494 Python 2.2 detects this error at regexp compilation time;
495 previously, the error went undetected, and results were
496 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
497 pattern.subn() methods have been rewritten in C. Also, an
498 experimental function/method finditer() has been added, which works
499 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000500
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000501- Tix exposes more commands through the classes DirSelectBox,
502 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
503 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
504 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
505
Tim Peters98791af2001-10-23 01:59:54 +0000506- Traceback objects are now scanned by cyclic garbage collection, so
507 cycles created by casual use of sys.exc_info() no longer cause
508 permanent memory leaks (provided garbage collection is enabled).
509
Guido van Rossum49192142001-10-24 20:51:44 +0000510- os.extsep -- a new variable needed by the RISCOS support. It is the
511 separator used by extensions, and is '.' on all platforms except
512 RISCOS, where it is '/'. There is no need to use this variable
513 unless you have a masochistic desire to port your code to RISCOS.
514
Barry Warsaw012852b2001-11-16 16:17:27 +0000515- mimetypes.py has optional support for non-standard, but commonly
516 found types. guess_type() and guess_extension() now accept an
517 optional `strict' flag, defaulting to true, which controls whether
518 recognize non-standard types or not. A few non-standard types we
519 know about have been added. Also, when run as a script, there are
520 new -l and -e options.
521
522- statcache is now deprecated.
523
524- email.Utils.formatdate() now produces the preferred RFC 2822 style
525 dates with numeric timezones (it used to produce obsolete dates
526 hard coded to "GMT" timezone). An optional `localtime' flag is
527 added to produce dates in the local timezone, with daylight savings
528 time properly taken into account.
529
530- In pickle and cPickle, instead of masking errors in load() by
531 transforming them into SystemError, we let the original exception
532 propagate out. Also, implement support for __safe_for_unpickling__
533 in pickle, as it already was supported in cPickle.
534
Tim Peters84362bc2001-10-19 17:55:30 +0000535Tools/Demos
536
537Build
538
Barry Warsaw012852b2001-11-16 16:17:27 +0000539- The dbm module is built using libdb1 if available. The bsddb module
540 is built with libdb3 if available.
541
542- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
543
Tim Peters84362bc2001-10-19 17:55:30 +0000544C API
545
Tim Peters1fc240e2001-10-26 05:06:50 +0000546- New function PySequence_Fast_GET_SIZE() returns the size of a non-
547 NULL result from PySequence_Fast(), more quickly than calling
548 PySequence_Size().
549
Barry Warsaw012852b2001-11-16 16:17:27 +0000550- New argument unpacking function PyArg_UnpackTuple() added.
551
552- New functions PyObject_CallFunctionObjArgs() and
553 PyObject_CallMethodObjArgs() have been added to make it more
554 convenient and efficient to call functions and methods from C.
555
556- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
557 possible that this will propagate errors it didn't before.
558
559- New function PyObject_CheckReadBuffer(), which returns true if its
560 argument supports the single-segment readable buffer interface.
561
Tim Peters84362bc2001-10-19 17:55:30 +0000562New platforms
563
Guido van Rossum86443212001-10-27 22:28:54 +0000564- We've finally confirmed that this release builds on HP-UX 11.00,
565 *with* threads, and passes the test suite.
566
Tim Peters7a33d8b2001-11-05 02:51:07 +0000567- Thanks to a series of patches from Michael Muller, Python may build
568 again under OS/2 Visual Age C++.
569
Guido van Rossum49192142001-10-24 20:51:44 +0000570- Updated RISCOS port by Dietmar Schwertberger.
571
Tim Peters84362bc2001-10-19 17:55:30 +0000572Tests
573
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000574- Added a test script for the curses module. It isn't run automatically;
575 regrtest.py must be run with '-u curses' to enable it.
576
Tim Peters84362bc2001-10-19 17:55:30 +0000577Windows
578
Barry Warsaw012852b2001-11-16 16:17:27 +0000579Mac
580
581- PythonScript has been moved to unsupported and is slated to be
582 removed completely in the next release.
583
584- It should now be possible to build applets that work on both OS9 and
585 OSX.
586
587- The core is now linked with CoreServices not Carbon; as a side
588 result, default 8bit encoding on OSX is now ASCII.
589
590- Python should now build on OSX 10.1.1
591
Tim Peters84362bc2001-10-19 17:55:30 +0000592
Tim Petersabf925f2001-09-28 21:53:42 +0000593What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000594Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000595===========================
596
597Type/class unification and new-style classes
598
Guido van Rossum687ae002001-10-15 22:03:32 +0000599- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000600 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000601 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000602 remains: the __dict__ of a new-style class is a read-only proxy; you
603 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000604 __defined__ attribute of new-style types no longer exists, for lack
605 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000606 future a __cache__ may be resurrected with a similar function, if I
607 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000608
Tim Peters1c9ca872001-10-04 06:43:12 +0000609- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
610 always returned None, even when there was a class docstring).
611
612- doctest now finds and runs docstrings attached to new-style classes,
613 class methods, static methods, and properties.
614
Guido van Rossum9074ef62001-10-16 21:34:49 +0000615Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000616
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000617- A very subtle syntactical pitfall in list comprehensions was fixed.
618 For example: [a+b for a in 'abc', for b in 'def']. The comma in
619 this example is a mistake. Previously, this would silently let 'a'
620 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
621 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
622 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
623 Note that [a for a in <singleton>] is a convoluted way to say
624 [<singleton>] anyway, so it's not like any expressiveness is lost.
625
Guido van Rossum9074ef62001-10-16 21:34:49 +0000626- getattr(obj, name, default) now only catches AttributeError, as
627 documented, rather than returning the default value for all
628 exceptions (which could mask bugs in a __getattr__ hook, for
629 example).
630
Fred Drakecb7a6b52001-10-22 18:41:51 +0000631- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000632 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000633 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000634 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000635
Guido van Rossum1c486092001-10-19 02:05:35 +0000636- unicode(obj) now behaves more like str(obj), accepting arbitrary
637 objects, and calling a __unicode__ method if it exists.
638 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000639 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000640
Barry Warsawf6fb1712001-10-19 05:35:40 +0000641- isinstance() now allows any object as the first argument and a
642 class, a type or something with a __bases__ tuple attribute for the
643 second argument. The second argument may also be a tuple of a
644 class, type, or something with __bases__, in which case isinstance()
645 will return true if the first argument is an instance of any of the
646 things contained in the second argument tuple. E.g.
647
648 isinstance(x, (A, B))
649
650 returns true if x is an instance of A or B.
651
Guido van Rossum9074ef62001-10-16 21:34:49 +0000652Extension modules
653
654- thread.start_new_thread() now returns the thread ID (previously None).
655
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000656- binascii has now two quopri support functions, a2b_qp and b2a_qp.
657
Guido van Rossumc524d952001-10-19 01:31:59 +0000658- readline now supports setting the startup_hook and the
659 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000660
Guido van Rossumc524d952001-10-19 01:31:59 +0000661- os and posix supports chroot(), setgroups() and unsetenv() where
662 available. The stat(), fstat(), statvfs() and fstatvfs() functions
663 now return "pseudo-sequences" -- the various fields can now be
664 accessed as attributes (e.g. os.stat("/").st_mtime) but for
665 backwards compatibility they also behave as a fixed-length sequence.
666 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000667 attributes.
668
669- time: localtime(), gmtime() and strptime() now return a
670 pseudo-sequence similar to the os.stat() return value, with
671 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000672
Guido van Rossum9074ef62001-10-16 21:34:49 +0000673- Decompression objects in the zlib module now accept an optional
674 second parameter to decompress() that specifies the maximum amount
675 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000676
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000677- optional SSL support in the socket module now exports OpenSSL
678 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
679 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000680 automatically seed its PRNG. Also, the keyfile and certfile
681 arguments to socket.ssl() are now optional.
682
683- posixmodule (and by extension, the os module on POSIX platforms) now
684 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000685
Guido van Rossum9074ef62001-10-16 21:34:49 +0000686Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000687
Tim Peters7402f792001-10-02 03:53:41 +0000688- doctest now excludes functions and classes not defined by the module
689 being tested, thanks to Tim Hochberg.
690
Fred Drakecb7a6b52001-10-22 18:41:51 +0000691- HotShot, a new profiler implemented using a C-based callback, has
692 been added. This substantially reduces the overhead of profiling,
693 but it is still quite preliminary. Support modules and
694 documentation will be added in upcoming releases (before 2.2 final).
695
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000696- profile now produces correct output in situations where an exception
697 raised in Python is cleared by C code (e.g. hasattr()). This used
698 to cause wrong output, including spurious claims of recursive
699 functions and attribution of time spent to the wrong function.
700
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000701 The code and documentation for the derived OldProfile and HotProfile
702 profiling classes was removed. The code hasn't worked for years (if
703 you tried to use them, they raised exceptions). OldProfile
704 intended to reproduce the behavior of the profiler Python used more
705 than 7 years ago, and isn't interesting anymore. HotProfile intended
706 to provide a faster profiler (but producing less information), and
707 that's a worthy goal we intend to meet via a different approach (but
708 without losing information).
709
Tim Peterscce092d2001-10-09 05:31:56 +0000710- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000711 a much better system-specific calibration constant. The constant can
712 now be specified in an instance constructor, or as a Profile class or
713 instance variable, instead of by editing profile.py's source code.
714 Calibration must still be done manually (see the docs for the profile
715 module).
716
717 Note that Profile.calibrate() must be overriden by subclasses.
718 Improving the accuracy required exploiting detailed knowledge of
719 profiler internals; the earlier method abstracted away the details
720 and measured a simplified model instead, but consequently computed
721 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000722
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000723- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000724 which indicates whether output is intended for the header 'Q'
725 encoding.
726
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000727- The SocketServer.ThreadingMixIn class now closes the request after
728 finish_request() returns. (Not when it errors out though.)
729
Barry Warsawf6fb1712001-10-19 05:35:40 +0000730- The nntplib module's NNTP.body() method has grown a `file' argument
731 to allow saving the message body to a file.
732
733- The email package has added a class email.Parser.HeaderParser which
734 only parses headers and does not recurse into the message's body.
735 Also, the module/class MIMEAudio has been added for representing
736 audio data (contributed by Anthony Baxter).
737
738- ftplib should be able to handle files > 2GB.
739
740- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
741 ON, and OFF.
742
Fred Drakecb7a6b52001-10-22 18:41:51 +0000743- xml.dom.minidom NodeList objects now support the length attribute
744 and item() method as required by the DOM specifications.
745
Guido van Rossumed554f62001-10-02 23:15:37 +0000746Tools/Demos
747
748- Demo/dns was removed. It no longer serves any purpose; a package
749 derived from it is now maintained by Anthony Baxter, see
750 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000751
Barry Warsawf6fb1712001-10-19 05:35:40 +0000752- The freeze tool has been made more robust, and two new options have
753 been added: -X and -E.
754
Tim Petersabf925f2001-09-28 21:53:42 +0000755Build
756
Barry Warsawf6fb1712001-10-19 05:35:40 +0000757- configure will use CXX in LINKCC if CXX is used to build main() and
758 the system requires to link a C++ main using the C++ compiler.
759
Tim Petersabf925f2001-09-28 21:53:42 +0000760C API
761
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000762- The documentation for the tp_compare slot is updated to require that
763 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
764 not correct. This is not yet enforced but will be enforced in
765 Python 2.3; even later, we may use -2 to indicate errors and +2 for
766 "NotImplemented". Right now, -1 should be used for an error return.
767
Tim Petersd38b1c72001-09-30 05:09:37 +0000768- PyLong_AsLongLong() now accepts int (as well as long) arguments.
769 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
770 as long) arguments.
771
Guido van Rossum3c288632001-10-16 21:13:49 +0000772- PyThread_start_new_thread() now returns a long int giving the thread
773 ID, if one can be calculated; it returns -1 for error, 0 if no
774 thread ID is calculated (this is an incompatible change, but only
775 the thread module used this API). This code has only really been
776 tested on Linux and Windows; other platforms please beware (and
777 report any bugs or strange behavior).
778
Guido van Rossum1c486092001-10-19 02:05:35 +0000779- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
780 input.
781
Tim Petersabf925f2001-09-28 21:53:42 +0000782New platforms
783
784Tests
785
786Windows
787
Tim Peters04cf1d32001-10-09 22:39:40 +0000788- Installer: If you install IDLE, and don't disable file-extension
789 registration, a new "Edit with IDLE" context (right-click) menu entry
790 is created for .py and .pyw files.
791
Tim Peters1ce3cf72001-10-01 17:58:40 +0000792- The signal module now supports SIGBREAK on Windows, thanks to Steven
793 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
794 action remains to call Win32 ExitProcess(). This can be changed via
795 signal.signal(). For example:
796
797 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
798 # (SIGINT) behavior.
799 import signal
800 signal.signal(signal.SIGBREAK,
801 signal.default_int_handler)
802
803 try:
804 while 1:
805 pass
806 except KeyboardInterrupt:
807 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
808 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
809 # program without the possibility for any Python-level cleanup).
810 print "Clean exit"
811
Tim Petersabf925f2001-09-28 21:53:42 +0000812
Tim Petersb07352e2001-09-08 01:25:47 +0000813What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000814Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000815===========================
816
Guido van Rossum808eea72001-09-25 04:15:41 +0000817Type/class unification and new-style classes
818
819- pydoc and inspect are now aware of new-style classes;
820 e.g. help(list) at the interactive prompt now shows proper
821 documentation for all operations on list objects.
822
823- Applications using Jim Fulton's ExtensionClass module can now safely
824 be used with Python 2.2. In particular, Zope 2.4.1 now works with
825 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
826 examples also work again. It is hoped that Gtk and Boost also work
827 with 2.2a4 and beyond. (If you can confirm this, please write
828 webmaster@python.org; if there are still problems, please open a bug
829 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000830
Tim Peters66c1a522001-09-24 21:17:50 +0000831- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
832 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
833 in the constructed property object. fget, fset and fdel weren't
834 discoverable from Python in 2.2a3. __doc__ is new, and allows to
835 associate a docstring with a property.
836
Guido van Rossum808eea72001-09-25 04:15:41 +0000837- Comparison overloading is now more completely implemented. For
838 example, a str subclass instance can properly be compared to a str
839 instance, and it can properly overload comparison. Ditto for most
840 other built-in object types.
841
842- The repr() of new-style classes has changed; instead of <type
843 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
844 *except* for built-in types, which are still rendered as <type
845 'Foo'> (to avoid upsetting existing code that might parse or
846 otherwise rely on repr() of certain type objects).
847
848- The repr() of new-style objects is now always <Foo object at XXX>;
849 previously, it was sometimes <Foo instance at XXX>.
850
851- For new-style classes, what was previously called __getattr__ is now
852 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000853 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000854 one in classic classes is defined which is called only if regular
855 attribute access raises AttributeError; to catch *all* attribute
856 access, you can use __getattribute__ (for new-style classes). If
857 both are defined, __getattribute__ is called first, and if it raises
858 AttributeError, __getattr__ is called.
859
860- The __class__ attribute of new-style objects can be assigned to.
861 The new class must have the same C-level object layout as the old
862 class.
863
864- The builtin file type can be subclassed now. In the usual pattern,
865 "file" is the name of the builtin type, and file() is a new builtin
866 constructor, with the same signature as the builtin open() function.
867 file() is now the preferred way to open a file.
868
869- Previously, __new__ would only see sequential arguments passed to
870 the type in a constructor call; __init__ would see both sequential
871 and keyword arguments. This made no sense whatsoever any more, so
872 now both __new__ and __init__ see all arguments.
873
874- Previously, hash() applied to an instance of a subclass of str or
875 unicode always returned 0. This has been repaired.
876
877- Previously, an operation on an instance of a subclass of an
878 immutable type (int, long, float, complex, tuple, str, unicode),
879 where the subtype didn't override the operation (and so the
880 operation was handled by the builtin type), could return that
881 instance instead a value of the base type. For example, if s was of
882 a str sublass type, s[:] returned s as-is. Now it returns a str
883 with the same value as s.
884
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000885- Provisional support for pickling new-style objects has been added.
886
Guido van Rossum808eea72001-09-25 04:15:41 +0000887Core
888
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000889- file.writelines() now accepts any iterable object producing strings.
890
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000891- PyUnicode_FromEncodedObject() now works very much like
892 PyObject_Str(obj) in that it tries to use __str__/tp_str
893 on the object if the object is not a string or buffer. This
894 makes unicode() behave like str() when applied to non-string/buffer
895 objects.
896
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000897- PyFile_WriteObject now passes Unicode objects to the file's write
898 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000899 of a print statement must support Unicode objects, i.e. they must
900 at least convert them into ASCII strings.
901
Guido van Rossum624c8af2001-09-18 15:21:04 +0000902- Thread scheduling on Solaris should be improved; it is no longer
903 necessary to insert a small sleep at the start of a thread in order
904 to let other runnable threads be scheduled.
905
Tim Petersb07352e2001-09-08 01:25:47 +0000906Library
907
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000908- StringIO.StringIO instances and cStringIO.StringIO instances support
909 read character buffer compatible objects for their .write() methods.
910 These objects are converted to strings and then handled as such
911 by the instances.
912
Barry Warsaw2f600732001-09-24 04:28:10 +0000913- The "email" package has been added. This is basically a port of the
914 mimelib package <http://sf.net/projects/mimelib> with API changes
915 and some implementations updated to use iterators and generators.
916
Tim Peters8a9c2842001-09-22 21:30:22 +0000917- difflib.ndiff() and difflib.Differ.compare() are generators now. This
918 restores the ability of Tools/scripts/ndiff.py to start producing output
919 before the entire comparison is complete.
920
Barry Warsaw58b072d2001-09-22 04:44:21 +0000921- StringIO.StringIO instances and cStringIO.StringIO instances support
922 iteration just like file objects (i.e. their .readline() method is
923 called for each iteration until it returns an empty string).
924
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000925- The codecs module has grown four new helper APIs to access
926 builtin codecs: getencoder(), getdecoder(), getreader(),
927 getwriter().
928
Guido van Rossum624c8af2001-09-18 15:21:04 +0000929- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
930 simplifies writing XML RPC servers.
931
Barry Warsaw647d5e82001-09-28 17:01:02 +0000932- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000933 after interpretation of symbolic links. On non-Unix systems, this
934 is an alias for os.path.abspath().
935
Tim Peters16a77ad2001-09-08 04:00:12 +0000936- operator.indexOf() (PySequence_Index() in the C API) now works with any
937 iterable object.
938
Guido van Rossum624c8af2001-09-18 15:21:04 +0000939- smtplib now supports various authentication and security features of
940 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000941
Guido van Rossum624c8af2001-09-18 15:21:04 +0000942- hmac: a new module implementing keyed hashing for message
943 authentication.
944
945- mimetypes now recognizes more extensions and file types. At the
946 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000947
Guido van Rossum624c8af2001-09-18 15:21:04 +0000948- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000949 Python 2.2 bytecode generation. It has also been promoted from a
950 Tool to a standard library package. (Tools/compiler still exists as
951 a sample driver.)
952
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000953Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000954
Tim Petersb07352e2001-09-08 01:25:47 +0000955Build
956
Guido van Rossum624c8af2001-09-18 15:21:04 +0000957- Large file support (LFS) is now automatic when the platform supports
958 it; no more manual configuration tweaks are needed. On Linux, at
959 least, it's possible to have a system whose C library supports large
960 files but whose kernel doesn't; in this case, large file support is
961 still enabled but doesn't do you any good unless you upgrade your
962 kernel or share your Python executable with another system whose
963 kernel has large file support.
964
965- The configure script now supplies plausible defaults in a
966 cross-compilation environment. This doesn't mean that the supplied
967 values are always correct, or that cross-compilation now works
968 flawlessly -- but it's a first step (and it shuts up most of
969 autoconf's warnings about AC_TRY_RUN).
970
971- The Unix build is now a bit less chatty, courtesy of the parser
972 generator. The build is completely silent (except for errors) when
973 using "make -s", thanks to a -q option to setup.py.
974
Tim Petersb07352e2001-09-08 01:25:47 +0000975C API
976
Guido van Rossum624c8af2001-09-18 15:21:04 +0000977- The "structmember" API now supports some new flag bits to deny read
978 and/or write access to attributes in restricted execution mode.
979
Tim Petersb07352e2001-09-08 01:25:47 +0000980New platforms
981
Guido van Rossum624c8af2001-09-18 15:21:04 +0000982- Compaq's iPAQ handheld, running the "familiar" Linux distribution
983 (http://familiar.handhelds.org).
984
Tim Petersb07352e2001-09-08 01:25:47 +0000985Tests
986
Tim Peters8a9c2842001-09-22 21:30:22 +0000987- The "classic" standard tests, which work by comparing stdout to
988 an expected-output file under Lib/test/output/, no longer stop at
989 the first mismatch. Instead the test is run to completion, and a
990 variant of ndiff-style comparison is used to report all differences.
991 This is much easier to understand than the previous style of reporting.
992
993- The unittest-based standard tests now use regrtest's test_main()
994 convention, instead of running as a side-effect of merely being
995 imported. This allows these tests to be run in more natural and
996 flexible ways as unittests, outside the regrtest framework.
997
998- regrtest.py is much better integrated with unittest and doctest now,
999 especially in regard to reporting errors.
1000
Tim Petersb07352e2001-09-08 01:25:47 +00001001Windows
1002
Guido van Rossum624c8af2001-09-18 15:21:04 +00001003- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +00001004 that support it (NTFS under Windows 2000). See "What's New in
1005 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +00001006
Tim Petersb07352e2001-09-08 01:25:47 +00001007
Tim Petersedc99312001-08-22 21:36:50 +00001008What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001009Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +00001010===========================
1011
1012Core
1013
Tim Peters9fffa3e2001-09-04 05:14:19 +00001014- Conversion of long to float now raises OverflowError if the long is too
1015 big to represent as a C double.
1016
Tim Peters32f453e2001-09-03 08:35:41 +00001017- The 3-argument builtin pow() no longer allows a third non-None argument
1018 if either of the first two arguments is a float, or if both are of
1019 integer types and the second argument is negative (in which latter case
1020 the arguments are converted to float, so this is really the same
1021 restriction).
1022
Tim Peters5d2b77c2001-09-03 05:47:38 +00001023- The builtin dir() now returns more information, and sometimes much
1024 more, generally naming all attributes of an object, and all attributes
1025 reachable from the object via its class, and from its class's base
1026 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
1027 an empty list. In 2.2a3,
1028
1029 >>> dir([])
1030 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
1031 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
1032 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
1033 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
1034 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1035 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1036 'reverse', 'sort']
1037
1038 dir(module) continues to return only the module's attributes, though.
1039
Tim Petersbdee63f2001-09-02 03:40:59 +00001040- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001041 than raising OverflowError. This is a partial implementation of PEP
1042 237. You can use -Wdefault::OverflowWarning to enable a warning for
1043 this situation, and -Werror::OverflowWarning to revert to the old
1044 OverflowError exception.
1045
Guido van Rossum61c345f2001-09-04 03:26:15 +00001046- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001047 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001048 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1049 -Qold, meaning the / operator has its classic meaning and no
1050 warnings are issued. Using -Qwarn issues a run-time warning about
1051 all uses of classic division for int and long arguments; -Qwarnall
1052 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001053 (for use with fixdiv.py).
1054 [Note: the remainder of this paragraph (preserved below) became
1055 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1056 <obsolete>
1057 Using -Qnew is questionable; it turns on new division by default, but
1058 only in the __main__ module. You can usefully combine -Qwarn or
1059 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1060 warns about classic division everywhere else.
1061 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001062
Tim Petersbdee63f2001-09-02 03:40:59 +00001063- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001064 long, float, str, unicode, and tuple. (The types complex, list and
1065 dictionary can also be subclassed; this was introduced earlier.)
1066 Note that restrictions apply when subclassing immutable built-in
1067 types: you can only affect the value of the instance by overloading
1068 __new__. You can add mutable attributes, and the subclass instances
1069 will have a __dict__ attribute, but you cannot change the "value"
1070 (as implemented by the base class) of an immutable subclass instance
1071 once it is created.
1072
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001073- The dictionary constructor now takes an optional argument, a
1074 mapping-like object, and initializes the dictionary from its
1075 (key, value) pairs.
1076
Tim Petersbdee63f2001-09-02 03:40:59 +00001077- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001078 "cooperative super calls" in a multiple inheritance setting. For an
1079 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1080
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001081- A new built-in type, property, has been added. This enables the
1082 creation of "properties". These are attributes implemented by
1083 getter and setter functions (or only one of these for read-only or
1084 write-only attributes), without the need to override __getattr__.
1085 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001086
Tim Petersbdee63f2001-09-02 03:40:59 +00001087- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001088 liberalized, to allow leading zeroes. Examples of literals now
1089 legal that were SyntaxErrors before:
1090
1091 00.0 0e3 0100j 07.5 00000000000000000008.
1092
Tim Petersbdee63f2001-09-02 03:40:59 +00001093- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001094 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1095
Tim Petersedc99312001-08-22 21:36:50 +00001096Library
1097
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001098- telnetlib includes symbolic names for the options, and support for
1099 setting an option negotiation callback.
1100
Tim Petersa40c7932001-09-05 22:36:56 +00001101- The new C standard no longer requires that math libraries set errno to
1102 ERANGE on overflow. For platform libraries that exploit this new
1103 freedom, Python's overflow-checking was wholly broken. A new overflow-
1104 checking scheme attempts to repair that, but may not be reliable on all
1105 platforms (C doesn't seem to provide anything both useful and portable
1106 in this area anymore).
1107
Martin v. Löwis44f86962001-09-05 13:44:54 +00001108- Asynchronous timeout actions are available through the new class
1109 threading.Timer.
1110
Tim Peters78526162001-09-05 00:53:45 +00001111- math.log and math.log10 now return sensible results for even huge
1112 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1113
Tim Petersbdee63f2001-09-02 03:40:59 +00001114- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001115 currently held. See the docs for the imp module.
1116
Tim Petersbdee63f2001-09-02 03:40:59 +00001117- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001118 dumps containing ints written on platforms where Python ints are 8 bytes.
1119 When read on a box where Python ints are 4 bytes, such values are
1120 converted to Python longs.
1121
Tim Petersbdee63f2001-09-02 03:40:59 +00001122- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001123 code objects is no longer allowed. This plugs a security hole.
1124
Steve Purcell6091cd62001-09-06 16:05:17 +00001125- unittest.TestResult instances no longer store references to tracebacks
1126 generated by test failures. This prevents unexpected dangling references
1127 to objects that should be garbage collected between tests.
1128
Tim Petersedc99312001-08-22 21:36:50 +00001129Tools
1130
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001131- Tools/scripts/fixdiv.py has been added which can be used to fix
1132 division operators as per PEP 238.
1133
Tim Petersedc99312001-08-22 21:36:50 +00001134Build
1135
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001136- If you are an adventurous person using Mac OS X you may want to look at
1137 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1138 application, which can be used for experimenting with Carbon or Cocoa.
1139 Discussion of this on pythonmac-sig, please.
1140
Tim Peters7eea37e2001-09-04 22:08:56 +00001141C API
1142
1143- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001144
Tim Peters9fffa3e2001-09-04 05:14:19 +00001145- Note that PyLong_AsDouble can fail! This has always been true, but no
1146 callers checked for it. It's more likely to fail now, because overflow
1147 errors are properly detected now. The proper way to check:
1148
1149 double x = PyLong_AsDouble(some_long_object);
1150 if (x == -1.0 && PyErr_Occurred()) {
1151 /* The conversion failed. */
1152 }
1153
Tim Petersbdee63f2001-09-02 03:40:59 +00001154- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001155 compile but will not participate in GC. To upgrade an extension
1156 module:
1157
1158 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001159
Neil Schemenauer4042c692001-08-30 15:38:01 +00001160 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1161 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001162
Neil Schemenauer4042c692001-08-30 15:38:01 +00001163 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1164 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001165
Neil Schemenauer4042c692001-08-30 15:38:01 +00001166 - remove PyGC_HEAD_SIZE from object size calculations
1167
1168 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1169
Tim Petersbdee63f2001-09-02 03:40:59 +00001170- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001171 These can be used safely to construct string objects from a
1172 sprintf-style format string (similar to the format string supported
1173 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001174
Tim Petersedc99312001-08-22 21:36:50 +00001175New platforms
1176
Tim Petersb7da0902001-09-02 23:01:43 +00001177- Stephen Hansen contributed patches sufficient to get a clean compile
1178 under Borland C (Windows), but he reports problems running it and ran
1179 out of time to complete the port. Volunteers? Expect a MemoryError
1180 when importing the types module; this is probably shallow, and
1181 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001182
Tim Petersedc99312001-08-22 21:36:50 +00001183Tests
1184
1185Windows
1186
Tim Peters6e13a562001-09-06 00:32:15 +00001187- Large file support is now enabled on Win32 platforms as well as on
1188 Win64. This means that, for example, you can use f.tell() and f.seek()
1189 to manipulate files larger than 2 gigabytes (provided you have enough
1190 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001191 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1192 filesize limit, and large file support makes no difference there.
1193 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1194 NTFS has no practical limit on file size, and files of any size can be
1195 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001196
Tim Petersbdee63f2001-09-02 03:40:59 +00001197- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001198 points to command.com (patch from Brian Quinlan).
1199
Tim Petersedc99312001-08-22 21:36:50 +00001200
Tim Peters20f51a72001-07-21 02:31:40 +00001201What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001202Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001203===========================
1204
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001205Build
1206
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001207- Tim Peters developed a brand new Windows installer using Wise 8.1,
1208 generously donated to us by Wise Solutions.
1209
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001210- configure supports a new option --enable-unicode, with the values
1211 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1212 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001213
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001214- A new configure option --enable-framework builds a Mac OS X framework,
1215 which "make frameworkinstall" will install. This provides a starting
1216 point for more mac-like functionality, join pythonmac-sig@python.org
1217 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001218
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001219- The NeXT platform is no longer supported.
1220
1221- The `new' module is now statically linked.
1222
Tim Peters0afb6092001-08-15 06:06:44 +00001223Tools
1224
1225- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001226 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001227 the module docstring for details.
1228
Tim Peters20f51a72001-07-21 02:31:40 +00001229Tests
1230
Tim Peters5e824c32001-08-12 22:25:01 +00001231- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001232 platforms, allowing to give clearer test result output. regrtest
1233 also has optional --use/-u switch to run normally disabled tests
1234 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001235
Tim Peters20f51a72001-07-21 02:31:40 +00001236- Several new tests in the standard test suite, with special thanks to
1237 Nick Mathewson.
1238
1239Core
1240
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001241- The floor division operator // has been added as outlined in PEP
1242 238. The / operator still provides classic division (and will until
1243 Python 3.0) unless "from __future__ import division" is included, in
1244 which case the / operator will provide true division. The operator
1245 module provides truediv() and floordiv() functions. Augmented
1246 assignment variants are included, as are the equivalent overloadable
1247 methods and C API methods. See the PEP for a full discussion:
1248 <http://python.sf.net/peps/pep-0238.html>
1249
Tim Peters6cd6a822001-08-17 22:11:27 +00001250- Future statements are now effective in simulated interactive shells
1251 (like IDLE). This should "just work" by magic, but read Michael
1252 Hudson's "Future statements in simulated shells" PEP 264 for full
1253 details: <http://python.sf.net/peps/pep-0264.html>.
1254
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001255- The type/class unification (PEP 252-253) was integrated into the
1256 trunk and is not so tentative any more (the exact specification of
1257 some features is still tentative). A lot of work has done on fixing
1258 bugs and adding robustness and features (performance still has to
1259 come a long way).
1260
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001261- Warnings about a mismatch in the Python API during extension import
1262 now use the Python warning framework (which makes it possible to
1263 write filters for these warnings).
1264
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001265- A function's __dict__ (aka func_dict) will now always be a
1266 dictionary. It used to be possible to delete it or set it to None,
1267 but now both actions raise TypeErrors. It is still legal to set it
1268 to a dictionary object. Getting func.__dict__ before any attributes
1269 have been assigned now returns an empty dictionary instead of None.
1270
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001271- A new command line option, -E, was added which disables the use of
1272 all environment variables, or at least those that are specifically
1273 significant to Python. Usually those have a name starting with
1274 "PYTHON". This was used to fix a problem where the tests fail if
1275 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1276 older distribution.
1277
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001278Library
1279
Tim Peters5e824c32001-08-12 22:25:01 +00001280- New class Differ and new functions ndiff() and restore() in difflib.py.
1281 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001282 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001283
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001284- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1285 value using the minimal quoting required for the value; more
1286 reliable than using xml.sax.saxutils.escape() for attribute values.
1287
1288- Readline completion support for cmd.Cmd was added.
1289
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001290- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1291
1292- Added function threading.BoundedSemaphore()
1293
1294- Added Ka-Ping Yee's cgitb.py module.
1295
1296- The `new' module now exposes the CO_xxx flags.
1297
Martin v. Löwis560da622001-11-24 09:24:51 +00001298- The gc module offers the get_referents function.
1299
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001300New platforms
1301
1302C API
1303
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001304- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1305 which provide a cross-platform implementations for the
1306 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1307 the standard sprintf() and vsprintf() C lib APIs, these versions
1308 apply bounds checking on the used buffer which enhances protection
1309 against buffer overruns.
1310
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001311- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001312 and extensions using different Unicode widths is rendered next to
1313 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001314 will result in an ImportError. Unicode extensions writers must make
1315 sure to check the Unicode width compatibility in their extensions by
1316 using at least one of the mangled Unicode APIs in the extension.
1317
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001318- Two new flags METH_NOARGS and METH_O are available in method definition
1319 tables to simplify implementation of methods with no arguments and a
1320 single untyped argument. Calling such methods is more efficient than
1321 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1322 deprecated.
1323
Tim Petersc1731372001-08-04 08:12:36 +00001324Windows
1325
1326- "import module" now compiles module.pyw if it exists and nothing else
1327 relevant is found.
1328
Tim Peters20f51a72001-07-21 02:31:40 +00001329
Guido van Rossum55a78992001-07-17 17:22:32 +00001330What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001331Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001332===========================
1333
1334Core
Tim Petersa814db52001-05-14 07:05:58 +00001335
Tim Peters6d6c1a32001-08-02 04:15:00 +00001336- TENTATIVELY, a large amount of code implementing much of what's
1337 described in PEP 252 (Making Types Look More Like Classes) and PEP
1338 253 (Subtyping Built-in Types) was added. This will be released
1339 with Python 2.2a1. Documentation will be provided separately
1340 through http://www.python.org/2.2/. The purpose of releasing this
1341 with Python 2.2a1 is to test backwards compatibility. It is
1342 possible, though not likely, that a decision is made not to release
1343 this code as part of 2.2 final, if any serious backwards
1344 incompapatibilities are found during alpha testing that cannot be
1345 repaired.
1346
Guido van Rossum55a78992001-07-17 17:22:32 +00001347- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001348 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001349 more 'yield' statements. See PEP 255. Since this adds a new
1350 keyword to the language, this feature must be enabled by including a
1351 future statement: "from __future__ import generators" (see PEP 236).
1352 Generators will become a standard feature in a future release
1353 (probably 2.3). Without this future statement, 'yield' remains an
1354 ordinary identifier, but a warning is issued each time it is used.
1355 (These warnings currently don't conform to the warnings framework of
1356 PEP 230; we intend to fix this in 2.2a2.)
1357
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001358- The UTF-16 codec was modified to be more RFC compliant. It will now
1359 only remove BOM characters at the start of the string and then
1360 only if running in native mode (UTF-16-LE and -BE won't remove a
1361 leading BMO character).
1362
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001363- Strings now have a new method .decode() to complement the already
1364 existing .encode() method. These two methods provide direct access
1365 to the corresponding decoders and encoders of the registered codecs.
1366
1367 To enhance the usability of the .encode() method, the special
1368 casing of Unicode object return values was dropped (Unicode objects
1369 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001370
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001371 Both methods will now return whatever the codec in charge of the
1372 requested encoding returns as object, e.g. Unicode codecs will
1373 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1374 will return u"äöü"). This enables codec writer to create codecs
1375 for various simple to use conversions.
1376
1377 New codecs were added to demonstrate these new features (the .encode()
1378 and .decode() columns indicate the type of the returned objects):
1379
1380 Name | .encode() | .decode() | Description
1381 ----------------------------------------------------------------------
1382 uu | string | string | UU codec (e.g. for email)
1383 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001384 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001385 zlib | string | string | zlib compression
1386 hex | string | string | 2-byte hex codec
1387 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1388
Mark Hammond2a0af792001-05-14 03:09:36 +00001389- Some operating systems now support the concept of a default Unicode
1390 encoding for file system operations. Notably, Windows supports 'mbcs'
1391 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001392 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001393 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001394
1395 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001396 functions that return filenames (such as os.listdir()) to return Python
1397 string objects pre-encoded using the default file system encoding for
1398 the platform. As this encoding is likely to be different from Python's
1399 default encoding, converting this name to a Unicode object before passing
1400 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001401 would attempt to use its default encoding (generally ASCII) rather than
1402 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001403
Tim Petersa814db52001-05-14 07:05:58 +00001404 In general, this change simply removes surprises when working with
1405 Unicode and the file system, making these operations work as you expect,
1406 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001407 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001408
Tim Peters61dff2b2001-05-08 15:43:37 +00001409- Float (and complex) literals in source code were evaluated to full
1410 precision only when running from a .py file; the same code loaded from a
1411 .pyc (or .pyo) file could suffer numeric differences starting at about the
1412 12th significant decimal digit. For example, on a machine with IEEE-754
1413 floating arithmetic,
1414
1415 x = 9007199254740992.0
1416 print long(x)
1417
1418 printed 9007199254740992 if run directly from .py, but 9007199254740000
1419 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1420 str(float) instead of repr(float) when building code objects. marshal
1421 now uses repr(float) instead, which should reproduce floats to full
1422 machine precision (assuming the platform C float<->string I/O conversion
1423 functions are of good quality).
1424
1425 This may cause floating-point results to change in some cases, and
1426 usually for the better, but may also cause numerically unstable
1427 algorithms to break.
1428
Tim Peters2f228e72001-05-13 00:19:31 +00001429- The implementation of dicts suffers fewer collisions, which has speed
1430 benefits. However, the order in which dict entries appear in dict.keys(),
1431 dict.values() and dict.items() may differ from previous releases for a
1432 given dict. Nothing is defined about this order, so no program should
1433 rely on it. Nevertheless, it's easy to write test cases that rely on the
1434 order by accident, typically because of printing the str() or repr() of a
1435 dict to an "expected results" file. See Lib/test/test_support.py's new
1436 sortdict(dict) function for a simple way to display a dict in sorted
1437 order.
1438
Tim Peters7a3bfc32001-06-12 01:22:22 +00001439- Many other small changes to dicts were made, resulting in faster
1440 operation along the most common code paths.
1441
Guido van Rossum10315822001-05-01 20:54:30 +00001442- Dictionary objects now support the "in" operator: "x in dict" means
1443 the same as dict.has_key(x).
1444
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001445- The update() method of dictionaries now accepts generic mapping
1446 objects. Specifically the argument object must support the .keys()
1447 and __getitem__() methods. This allows you to say, for example,
1448 {}.update(UserDict())
1449
Guido van Rossum10315822001-05-01 20:54:30 +00001450- Iterators were added; this is a generalized way of providing values
1451 to a for loop. See PEP 234. There's a new built-in function iter()
1452 to return an iterator. There's a new protocol to get the next value
1453 from an iterator using the next() method (in Python) or the
1454 tp_iternext slot (in C). There's a new protocol to get iterators
1455 using the __iter__() method (in Python) or the tp_iter slot (in C).
1456 Iterating (i.e. a for loop) over a dictionary generates its keys.
1457 Iterating over a file generates its lines.
1458
Tim Petersf553f892001-05-01 20:45:31 +00001459- The following functions were generalized to work nicely with iterator
1460 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001461 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001462 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1463 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001464 join() method of strings
1465 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001466 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1467 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001468 right-hand side of assignment statements with multiple targets, such as
1469 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001470
Tim Petersd85e1022001-05-11 21:51:48 +00001471- Accessing module attributes is significantly faster (for example,
1472 random.random or os.path or yourPythonModule.yourAttribute).
1473
Tim Peterse63415e2001-05-08 04:38:29 +00001474- Comparing dictionary objects via == and != is faster, and now works even
1475 if the keys and values don't support comparisons other than ==.
1476
Tim Peters95bf9392001-05-10 08:32:44 +00001477- Comparing dictionaries in ways other than == and != is slower: there were
1478 insecurities in the dict comparison implementation that could cause Python
1479 to crash if the element comparison routines for the dict keys and/or
1480 values mutated the dicts. Making the code bulletproof slowed it down.
1481
Tim Peterseb28ef22001-06-02 05:27:19 +00001482- Collisions in dicts are resolved via a new approach, which can help
1483 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001484 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001485 faster now. Thanks to Christian Tismer for pointing out the cause and
1486 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001487
Tim Peters52e155e2001-06-16 05:42:57 +00001488- repr() is much faster for large containers (dict, list, tuple).
1489
1490
Tim Petersa814db52001-05-14 07:05:58 +00001491Library
1492
Fred Drake960fdf92001-07-20 18:38:26 +00001493- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1494 were added to the string module. These a locale-indenpendent
1495 constants, unlike letters, lowercase, and uppercase. These are now
1496 use in appropriate locations in the standard library.
1497
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001498- The flags used in dlopen calls can now be configured using
1499 sys.setdlopenflags and queried using sys.getdlopenflags.
1500
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001501- Fredrik Lundh's xmlrpclib is now a standard library module. This
1502 provides full client-side XML-RPC support. In addition,
1503 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1504 one asyncore-based). Thanks to Eric Raymond for the documentation.
1505
Guido van Rossum643d3912001-07-05 14:46:25 +00001506- The xrange() object is simplified: it no longer supports slicing,
1507 repetition, comparisons, efficient 'in' checking, the tolist()
1508 method, or the start, stop and step attributes. See PEP 260.
1509
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001510- A new function fnmatch.filter to filter lists of file names was added.
1511
Barry Warsawffd674d2001-05-22 16:00:10 +00001512- calendar.py uses month and day names based on the current locale.
1513
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001514- strop is now *really* obsolete (this was announced before with 1.6),
1515 and issues DeprecationWarning when used (except for the four items
1516 that are still imported into string.py).
1517
Tim Petersa814db52001-05-14 07:05:58 +00001518- Cookie.py now sorts key+value pairs by key in output strings.
1519
1520- pprint.isrecursive(object) didn't correctly identify recursive objects.
1521 Now it does.
1522
Tim Peters95b3f782001-05-14 18:39:41 +00001523- pprint functions now much faster for large containers (tuple, list, dict).
1524
Tim Peters7b9542a2001-06-10 23:40:19 +00001525- New 'q' and 'Q' format codes in the struct module, corresponding to C
1526 types "long long" and "unsigned long long" (on Windows, __int64). In
1527 native mode, these can be used only when the platform C compiler supports
1528 these types (when HAVE_LONG_LONG is #define'd by the Python config
1529 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001530 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1531 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001532
Guido van Rossum83213cc2001-06-12 16:48:52 +00001533- The site module installs a new built-in function 'help' that invokes
1534 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1535 it displays a message reminding the user to use 'help()' or
1536 'help(object)'.
1537
Tim Petersa814db52001-05-14 07:05:58 +00001538Tests
1539
1540- New test_mutants.py runs dict comparisons where the key and value
1541 comparison operators mutute the dicts randomly during comparison. This
1542 rapidly causes Python to crash under earlier releases (not for the faint
1543 of heart: it can also cause Win9x to freeze or reboot!).
1544
1545- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001546 pprint.isreadable() return sensible results. Also verifies that simple
1547 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001548
Tim Peters4324aa32001-05-28 22:30:08 +00001549C API
1550
1551- Removed the unused last_is_sticky argument from the internal
1552 _PyTuple_Resize(). If this affects you, you were cheating.
1553
1554
Guido van Rossum55a78992001-07-17 17:22:32 +00001555======================================================================
1556
1557
Guido van Rossumffe13be2001-04-16 18:46:45 +00001558What's New in Python 2.1 (final)?
1559=================================
1560
1561We only changed a few things since the last release candidate, all in
1562Python library code:
1563
1564- A bug in the locale module was fixed that affected locales which
1565 define no grouping for numeric formatting.
1566
1567- A few bugs in the weakref module's implementations of weak
1568 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1569 and the test suite was updated to check for these bugs.
1570
1571- An old bug in the os.path.walk() function (introduced in Python
1572 2.0!) was fixed: a non-existent file would cause an exception
1573 instead of being ignored.
1574
1575- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1576 PyChecker.
1577
1578
Guido van Rossum5b08f132001-04-16 02:05:23 +00001579What's New in Python 2.1c2?
1580===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001581
Guido van Rossum5b08f132001-04-16 02:05:23 +00001582A flurry of small changes, and one showstopper fixed in the nick of
1583time made it necessary to release another release candidate. The list
1584here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001585
Guido van Rossum5b08f132001-04-16 02:05:23 +00001586Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001587
Guido van Rossum5b08f132001-04-16 02:05:23 +00001588- Tim discovered a nasty bug in the dictionary code, caused by
1589 PyDict_Next() calling dict_resize(), and the GC code's use of
1590 PyDict_Next() violating an assumption in dict_items(). This was
1591 fixed with considerable amounts of band-aid, but the net effect is a
1592 saner and more robust implementation.
1593
1594- Made a bunch of symbols static that were accidentally global.
1595
1596Build and Ports
1597
1598- The setup.py script didn't check for a new enough version of zlib
1599 (1.1.3 is needed). Now it does.
1600
1601- Changed "make clean" target to also remove shared libraries.
1602
1603- Added a more general warning about the SGI Irix optimizer to README.
1604
1605Library
1606
1607- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1608 omitted the slash between host and file.html.
1609
1610- The mailbox module's _Mailbox class contained a completely broken
1611 and undocumented seek() method. Ripped it out.
1612
1613- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1614 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1615
1616- Fixed a few last-minute bugs in unittest.
1617
1618Extensions
1619
1620- Reverted the patch to the OpenSSL code in socketmodule.c to support
1621 RAND_status() and the EGD, and the subsequent patch that tried to
1622 fix it for pre-0.9.5 versions; the problem with the patch is that on
1623 some systems it issues a warning whenever socket is imported, and
1624 that's unacceptable.
1625
1626Tests
1627
1628- Fixed the pickle tests to work with "import test.test_pickle".
1629
1630- Tweaked test_locale.py to actually run the test Windows.
1631
1632- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1633 not "wb" (which is not a valid mode at all).
1634
1635- Fix pstats browser crashes. Import readline if it exists to make
1636 the user interface nicer.
1637
1638- Add "import thread" to the top of test modules that import the
1639 threading module (test_asynchat and test_threadedtempfile). This
1640 prevents test failures caused by a broken threading module resulting
1641 from a previously caught failed import.
1642
1643- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1644 needed on some platforms (e.g. Solaris 8) when the tests are run
1645 twice in succession.
1646
1647- Skip rather than fail test_sunaudiodev if no audio device is found.
1648
1649
1650What's New in Python 2.1c1?
1651===========================
1652
1653This list was significantly updated when 2.1c2 was released; the 2.1c1
1654release didn't mention most changes that were actually part of 2.1c1:
1655
1656Legal
1657
1658- Copyright was assigned to the Python Software Foundation (PSF) and a
1659 PSF license (very similar to the CNRI license) was added.
1660
1661- The CNRI copyright notice was updated to include 2001.
1662
1663Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001664
Guido van Rossumc9932722001-04-12 02:31:27 +00001665- After a public outcry, assignment to __debug__ is no longer illegal;
1666 instead, a warning is issued. It will become illegal in 2.2.
1667
Guido van Rossum5b08f132001-04-16 02:05:23 +00001668- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1669 "%#x" now always prepends "0x", even if the value is zero.
1670
1671- Fixed some nits in the bytecode compiler.
1672
1673- Fixed core dumps when calling certain kinds of non-functions.
1674
1675- Fixed various core dumps caused by reference count bugs.
1676
1677Build and Ports
1678
1679- Use INSTALL_SCRIPT to install script files.
1680
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001681- New port: SCO Unixware 7, by Billy G. Allie.
1682
Guido van Rossum5b08f132001-04-16 02:05:23 +00001683- Updated RISCOS port.
1684
1685- Updated BeOS port and notes.
1686
1687- Various other porting problems resolved.
1688
1689Library
1690
1691- The TERMIOS and SOCKET modules are now truly obsolete and
1692 unnecessary. Their symbols are incorporated in the termios and
1693 socket modules.
1694
1695- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1696 better tests for pickling.
1697
1698- threading: make Condition.wait() robust against KeyboardInterrupt.
1699
1700- zipfile: add support to zipfile to support opening an archive
1701 represented by an open file rather than a file name. Fix bug where
1702 the archive was not properly closed. Fixed a bug in this bugfix
1703 where flush() was called for a read-only file.
1704
1705- imputil: added an uninstall() method to the ImportManager.
1706
1707- Canvas: fixed bugs in lower() and tkraise() methods.
1708
1709- SocketServer: API change (added overridable close_request() method)
1710 so that the TCP server can explicitly close the request.
1711
1712- pstats: Eric Raymond added a simple interactive statistics browser,
1713 invoked when the module is run as a script.
1714
1715- locale: fixed a problem in format().
1716
1717- webbrowser: made it work when the BROWSER environment variable has a
1718 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1719 KDE 2. Fixed some other nits.
1720
1721- unittest: changes to allow using a different exception than
1722 AssertionError, and added a few more function aliases. Some other
1723 small changes.
1724
1725- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1726
1727- asynchat: fixed a critical bug in asynchat that slipped through the
1728 2.1b2 release. Fixed another rare bug.
1729
1730- Fix some unqualified except: clauses (always a bad code example).
1731
1732XML
1733
1734- pyexpat: new API get_version_string().
1735
1736- Fixed some minidom bugs.
1737
1738Extensions
1739
1740- Fixed a core dump in _weakref. Removed the weakref.mapping()
1741 function (it adds nothing to the API).
1742
1743- Rationalized the use of header files in the readline module, to make
1744 it compile (albeit with some warnings) with the very recent readline
1745 4.2, without breaking for earlier versions.
1746
1747- Hopefully fixed a buffering problem in linuxaudiodev.
1748
1749- Attempted a fix to make the OpenSSL support in the socket module
1750 work again with pre-0.9.5 versions of OpenSSL.
1751
1752Tests
1753
1754- Added a test case for asynchat and asyncore.
1755
1756- Removed coupling between tests where one test failing could break
1757 another.
1758
1759Tools
1760
1761- Ping added an interactive help browser to pydoc, fixed some nits
1762 in the rest of the pydoc code, and added some features to his
1763 inspect module.
1764
1765- An updated python-mode.el version 4.1 which integrates Ken
1766 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1767 much nicer in XEmacs and Emacs. When stepping through your program
1768 with pdb, in either the shell window or the *Python* window, the
1769 source file and line will be tracked by an arrow. Very cool!
1770
1771- IDLE: syntax warnings in interactive mode are changed into errors.
1772
1773- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001774 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001775
1776- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001777
Barry Warsaw11e89c72001-04-11 20:37:57 +00001778
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001779What's New in Python 2.1 beta 2?
1780================================
1781
Guido van Rossum053ae352001-03-22 14:17:21 +00001782(Unlisted are many fixed bugs, more documentation, etc.)
1783
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001784Core language, builtins, and interpreter
1785
Guido van Rossum053ae352001-03-22 14:17:21 +00001786- The nested scopes work (enabled by "from __future__ import
1787 nested_scopes") is completed; in particular, the future now extends
1788 into code executed through exec, eval() and execfile(), and into the
1789 interactive interpreter.
1790
1791- When calling a base class method (e.g. BaseClass.__init__(self)),
1792 this is now allowed even if self is not strictly spoken a class
1793 instance (e.g. when using metaclasses or the Don Beaudry hook).
1794
1795- Slice objects are now comparable but not hashable; this prevents
1796 dict[:] from being accepted but meaningless.
1797
1798- Complex division is now calculated using less braindead algorithms.
1799 This doesn't change semantics except it's more likely to give useful
1800 results in extreme cases. Complex repr() now uses full precision
1801 like float repr().
1802
1803- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1804
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001805- It is illegal to assign to the name __debug__, which is set when the
1806 interpreter starts. It is effectively a compile-time constant.
1807
1808- A warning will be issued if a global statement for a variable
1809 follows a use or assignment of that variable.
1810
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001811Standard library
1812
Guido van Rossum053ae352001-03-22 14:17:21 +00001813- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1814 inspired by JUnit), is now part of the standard library. You now
1815 have a choice of two testing frameworks: unittest requires you to
1816 write testcases as separate code, doctest gathers them from
1817 docstrings. Both approaches have their advantages and
1818 disadvantages.
1819
1820- A new module Tix was added, which wraps the Tix extension library
1821 for Tk. With that module, it is not necessary to statically link
1822 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1823 require" command. See Demo/tix/.
1824
1825- tzparse.py is now obsolete.
1826
1827- In gzip.py, the seek() and tell() methods are removed -- they were
1828 non-functional anyway, and it's better if callers can test for their
1829 existence with hasattr().
1830
1831Python/C API
1832
1833- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1834 that's already in the dictionary during a PyDict_Next() iteration.
1835 This used to fail occasionally when a dictionary resize operation
1836 could be triggered that would rehash all the keys. All other
1837 modifications to the dictionary are still off-limits during a
1838 PyDict_Next() iteration!
1839
1840- New extended APIs related to passing compiler variables around.
1841
1842- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1843 implement isinstance() and issubclass().
1844
1845- Py_BuildValue() now has a "D" conversion to create a Python complex
1846 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001847
Fred Drake4e262a92001-03-22 18:26:47 +00001848- Extensions types which support weak references must now set the
1849 field allocated for the weak reference machinery to NULL themselves;
1850 this is done to avoid the cost of checking each object for having a
1851 weakly referencable type in PyObject_INIT(), since most types are
1852 not weakly referencable.
1853
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001854- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1855 free variables and cell variables to and from the frame's f_locals.
1856
1857- Variants of several functions defined in pythonrun.h have been added
1858 to support the nested_scopes future statement. The variants all end
1859 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1860 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1861 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001862 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001863
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001864Distutils
1865
1866- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1867 into the release tree.
1868
Tim Peters0e57abf2001-05-02 07:39:38 +00001869- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001870 (an uninstaller, more customization of the installer's display)
1871
1872- from Jack Jansen: added Mac-specific code to generate a dialog for
1873 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001874 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001875 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001876
1877- added 'platforms' and 'keywords' to the set of metadata that can be
1878 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001879
1880- applied patches from Jason Tishler to make the compiler class work with
1881 Cygwin.
1882
1883
Tim Peters2fe289a2001-03-01 22:19:38 +00001884What's New in Python 2.1 beta 1?
1885================================
Tim Petersd66595f2001-02-04 03:09:53 +00001886
1887Core language, builtins, and interpreter
1888
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001889- Following an outcry from the community about the amount of code
1890 broken by the nested scopes feature introduced in 2.1a2, we decided
1891 to make this feature optional, and to wait until Python 2.2 (or at
1892 least 6 months) to make it standard. The option can be enabled on a
1893 per-module basis by adding "from __future__ import nested_scopes" at
1894 the beginning of a module (before any other statements, but after
1895 comments and an optional docstring). See PEP 236 (Back to the
1896 __future__) for a description of the __future__ statement. PEP 227
1897 (Statically Nested Scopes) has been updated to reflect this change,
1898 and to clarify the semantics in a number of endcases.
1899
1900- The nested scopes code, when enabled, has been hardened, and most
1901 bugs and memory leaks in it have been fixed.
1902
1903- Compile-time warnings are now generated for a number of conditions
1904 that will break or change in meaning when nested scopes are enabled:
1905
1906 - Using "from...import *" or "exec" without in-clause in a function
1907 scope that also defines a lambda or nested function with one or
1908 more free (non-local) variables. The presence of the import* or
1909 bare exec makes it impossible for the compiler to determine the
1910 exact set of local variables in the outer scope, which makes it
1911 impossible to determine the bindings for free variables in the
1912 inner scope. To avoid the warning about import *, change it into
1913 an import of explicitly name object, or move the import* statement
1914 to the global scope; to avoid the warning about bare exec, use
1915 exec...in... (a good idea anyway -- there's a possibility that
1916 bare exec will be deprecated in the future).
1917
1918 - Use of a global variable in a nested scope with the same name as a
1919 local variable in a surrounding scope. This will change in
1920 meaning with nested scopes: the name in the inner scope will
1921 reference the variable in the outer scope rather than the global
1922 of the same name. To avoid the warning, either rename the outer
1923 variable, or use a global statement in the inner function.
1924
Neil Schemenauera35c6882001-02-27 04:45:05 +00001925- An optional object allocator has been included. This allocator is
1926 optimized for Python objects and should be faster and use less memory
1927 than the standard system allocator. It is not enabled by default
1928 because of possible thread safety problems. The allocator is only
1929 protected by the Python interpreter lock and it is possible that some
1930 extension modules require a thread safe allocator. The object
1931 allocator can be enabled by providing the "--with-pymalloc" option to
1932 configure.
1933
Tim Petersd66595f2001-02-04 03:09:53 +00001934Standard library
1935
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001936- pyexpat now detects the expat version if expat.h defines it. A
1937 number of additional handlers are provided, which are only available
1938 since expat 1.95. In addition, the methods SetParamEntityParsing and
1939 GetInputContext of Parser objects are available with 1.95.x
1940 only. Parser objects now provide the ordered_attributes and
1941 specified_attributes attributes. A new module expat.model was added,
1942 which offers a number of additional constants if 1.95.x is used.
1943
1944- xml.dom offers the new functions registerDOMImplementation and
1945 getDOMImplementation.
1946
1947- xml.dom.minidom offers a toprettyxml method. A number of DOM
1948 conformance issues have been resolved. In particular, Element now
1949 has an hasAttributes method, and the handling of namespaces was
1950 improved.
1951
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001952- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1953 getting information about live Python code, and pydoc.py, a module
1954 for interactively converting docstrings to HTML or text.
1955 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001956 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001957 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1958 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001959
Tim Peters1eff7962001-03-01 02:31:33 +00001960- New library module difflib.py, primarily packaging the SequenceMatcher
1961 class at the heart of the popular ndiff.py file-comparison tool.
1962
1963- doctest.py (a framework for verifying Python code examples in docstrings)
1964 is now part of the std library.
1965
Tim Petersd66595f2001-02-04 03:09:53 +00001966Windows changes
1967
Guido van Rossume3955a82001-03-02 14:05:59 +00001968- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1969 small GUI that lets you browse the module docstrings using your
1970 default web browser.
1971
Tim Peters1eff7962001-03-01 02:31:33 +00001972- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1973 Platforms) is implemented. See
1974
1975 http://python.sourceforge.net/peps/pep-0235.html
1976
1977 for full details, especially the "Current Lower-Left Semantics" section.
1978 The new Windows import rules are simpler than before:
1979
1980 A. If the PYTHONCASEOK environment variable exists, same as
1981 before: silently accept the first case-insensitive match of any
1982 kind; raise ImportError if none found.
1983
1984 B. Else search sys.path for the first case-sensitive match; raise
1985 ImportError if none found.
1986
1987 The same rules have been implented on other platforms with case-
1988 insensitive but case-preserving filesystems too (including Cygwin, and
1989 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001990
Tim Peters25a9ce32001-02-19 07:06:36 +00001991- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1992 what it's supposed to do (and does do under NT and 2000) via direct
1993 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001994 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001995 all Win9x systems before.
1996
Tim Peters1eff7962001-03-01 02:31:33 +00001997- Build: Subproject _test (effectively) renamed to _testcapi.
1998
Tim Peters2fe289a2001-03-01 22:19:38 +00001999New platforms
2000
2001- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
2002 Thanks to Steven Majewski!
2003
2004- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
2005 Tishler!
2006
Guido van Rossum9089b272001-03-02 06:49:50 +00002007- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
2008 Schwertberger! See RISCOS/README for more information -- it seems
2009 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00002010 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00002011
Tim Peters25a9ce32001-02-19 07:06:36 +00002012
Tim Petersd7b5e882001-01-25 03:36:26 +00002013What's New in Python 2.1 alpha 2?
2014=================================
Tim Peters40ead762001-01-27 05:35:26 +00002015
Tim Petersd7b5e882001-01-25 03:36:26 +00002016Core language, builtins, and interpreter
2017
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002018- Scopes nest. If a name is used in a function or class, but is not
2019 local, the definition in the nearest enclosing function scope will
2020 be used. One consequence of this change is that lambda statements
2021 could reference variables in the namespaces where the lambda is
2022 defined. In some unusual cases, this change will break code.
2023
2024 In all previous version of Python, names were resolved in exactly
2025 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002026 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00002027 function A is defined within a function B, the names bound in B are
2028 not visible in A. The new rules make names bound in B visible in A,
2029 unless A contains a name binding that hides the binding in B.
2030
2031 Section 4.1 of the reference manual describes the new scoping rules
2032 in detail. The test script in Lib/test/test_scope.py demonstrates
2033 some of the effects of the change.
2034
2035 The new rules will cause existing code to break if it defines nested
2036 functions where an outer function has local variables with the same
2037 name as globals or builtins used by the inner function. Example:
2038
2039 def munge(str):
2040 def helper(x):
2041 return str(x)
2042 if type(str) != type(''):
2043 str = helper(str)
2044 return str.strip()
2045
2046 Under the old rules, the name str in helper() is bound to the
2047 builtin function str(). Under the new rules, it will be bound to
2048 the argument named str and an error will occur when helper() is
2049 called.
2050
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002051- The compiler will report a SyntaxError if "from ... import *" occurs
2052 in a function or class scope. The language reference has documented
2053 that this case is illegal, but the compiler never checked for it.
2054 The recent introduction of nested scope makes the meaning of this
2055 form of name binding ambiguous. In a future release, the compiler
2056 may allow this form when there is no possibility of ambiguity.
2057
Tim Peters40ead762001-01-27 05:35:26 +00002058- repr(string) is easier to read, now using hex escapes instead of octal,
2059 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2060
2061 >>> "\texample \r\n" + chr(0) + chr(255)
2062 '\texample \r\n\x00\xff' # in 2.1
2063 '\011example \015\012\000\377' # in 2.0
2064
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002065- Functions are now compared and hashed by identity, not by value, since
2066 the func_code attribute is writable.
2067
Fred Drakefb9d7122001-02-01 20:00:40 +00002068- Weak references (PEP 205) have been added. This involves a few
2069 changes in the core, an extension module (_weakref), and a Python
2070 module (weakref). The weakref module is the public interface. It
2071 includes support for "explicit" weak references, proxy objects, and
2072 mappings with weakly held values.
2073
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002074- A 'continue' statement can now appear in a try block within the body
2075 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002076 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002077
Tim Petersd7b5e882001-01-25 03:36:26 +00002078Standard library
2079
Barry Warsaw30dbd142001-01-31 22:14:01 +00002080- mailbox.py now has a new class, PortableUnixMailbox which is
2081 identical to UnixMailbox but uses a more portable scheme for
2082 determining From_ separators. Also, the constructors for all the
2083 classes in this module have a new optional `factory' argument, which
2084 is a callable used when new message classes must be instantiated by
2085 the next() method.
2086
Tim Petersd7b5e882001-01-25 03:36:26 +00002087- random.py is now self-contained, and offers all the functionality of
2088 the now-deprecated whrandom.py. See the docs for details. random.py
2089 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002090 and restoring the internal state of the generator; and jumpahead(n),
2091 for quickly forcing the internal state to be the same as if n calls to
2092 random() had been made. The latter is particularly useful for multi-
2093 threaded programs, creating one instance of the random.Random() class for
2094 each thread, then using .jumpahead() to force each instance to use a
2095 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002096
Tim Peters0de88fc2001-02-01 04:59:18 +00002097- random.py's seed() function is new. For bit-for-bit compatibility with
2098 prior releases, use the whseed function instead. The new seed function
2099 addresses two problems: (1) The old function couldn't produce more than
2100 about 2**24 distinct internal states; the new one about 2**45 (the best
2101 that can be done in the Wichmann-Hill generator). (2) The old function
2102 sometimes produced identical internal states when passed distinct
2103 integers, and there was no simple way to predict when that would happen;
2104 the new one guarantees to produce distinct internal states for all
2105 arguments in [0, 27814431486576L).
2106
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002107- The socket module now supports raw packets on Linux. The socket
2108 family is AF_PACKET.
2109
Tim Peters9ea17ac2001-02-02 05:57:15 +00002110- test_capi.py is a start at running tests of the Python C API. The tests
2111 are implemented by the new Modules/_testmodule.c.
2112
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002113- A new extension module, _symtable, provides provisional access to the
2114 internal symbol table used by the Python compiler. A higher-level
2115 interface will be added on top of _symtable in a future release.
2116
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002117- Removed the obsolete soundex module.
2118
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002119- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2120 the isSameNode method; NamedNodeMap the get method.
2121
2122- xml.sax.expatreader supports the lexical handler property; it
2123 generates comment, startCDATA, and endCDATA events.
2124
Tim Petersee826f82001-01-31 19:39:44 +00002125Windows changes
2126
2127- Build procedure: the zlib project is built in a different way that
2128 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002129 the zlib binary used. See PCbuild\readme.txt for details. Your old
2130 zlib-related directories can be deleted; you'll need to download fresh
2131 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002132
Tim Peters9ea17ac2001-02-02 05:57:15 +00002133- Build: New subproject _test for the benefit of test_capi.py (see above).
2134
Tim Petersb16c56f2001-02-02 21:24:51 +00002135- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2136 interface to some Python compiler internals).
2137
2138- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002139 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002140
Tim Petersa3a3a032000-11-30 05:22:44 +00002141What's New in Python 2.1 alpha 1?
2142=================================
2143
2144Core language, builtins, and interpreter
2145
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002146- There is a new Unicode companion to the PyObject_Str() API
2147 called PyObject_Unicode(). It behaves in the same way as the
2148 former, but assures that the returned value is an Unicode object
2149 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002150
Guido van Rossumf98eda02001-01-17 15:54:45 +00002151- The comparison operators support "rich comparison overloading" (PEP
2152 207). C extension types can provide a rich comparison function in
2153 the new tp_richcompare slot in the type object. The cmp() function
2154 and the C function PyObject_Compare() first try the new rich
2155 comparison operators before trying the old 3-way comparison. There
2156 is also a new C API PyObject_RichCompare() (which also falls back on
2157 the old 3-way comparison, but does not constrain the outcome of the
2158 rich comparison to a Boolean result).
2159
2160 The rich comparison function takes two objects (at least one of
2161 which is guaranteed to have the type that provided the function) and
2162 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2163 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2164 object, which may be NotImplemented (in which case the tp_compare
2165 slot function is used as a fallback, if defined).
2166
2167 Classes can overload individual comparison operators by defining one
2168 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002169 __ge__. There are no explicit "reflected argument" versions of
2170 these; instead, __lt__ and __gt__ are each other's reflection,
2171 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2172 reflection (similar at the C level). No other implications are
2173 made; in particular, Python does not assume that == is the Boolean
2174 inverse of !=, or that < is the Boolean inverse of >=. This makes
2175 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002176
2177 Classes or types that want to implement (in)equality tests but not
2178 the ordering operators (i.e. unordered types) should implement ==
2179 and !=, and raise an error for the ordering operators.
2180
Guido van Rossuma88479f2001-01-18 14:28:08 +00002181 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002182 Boolean; e.g. a matrix type might want to return a matrix of bits
2183 for A < B, giving elementwise comparisons. Such types should ensure
2184 that any interpretation of their value in a Boolean context raises
2185 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2186 at the C level) to always raise an exception.
2187
Guido van Rossuma88479f2001-01-18 14:28:08 +00002188- Complex numbers use rich comparisons to define == and != but raise
2189 an exception for <, <=, > and >=. Unfortunately, this also means
2190 that cmp() of two complex numbers raises an exception when the two
2191 numbers differ. Since it is not mathematically meaningful to compare
2192 complex numbers except for equality, I hope that this doesn't break
2193 too much code.
2194
Tim Peters3389f192001-02-18 08:48:49 +00002195- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002196 not defined by the language, other than that it's arbitrary but
2197 consistent (see the Reference Manual). An implementation detail changed
2198 in 2.1a1 such that None now compares less than any other object. Code
2199 relying on this new behavior (like code that relied on the previous
2200 behavior) does so at its own risk.
2201
Barry Warsaw573b5412001-01-15 20:43:18 +00002202- Functions and methods now support getting and setting arbitrarily
2203 named attributes (PEP 232). Functions have a new __dict__
2204 (a.k.a. func_dict) which hold the function attributes. Methods get
2205 and set attributes on their underlying im_func. It is a TypeError
2206 to set an attribute on a bound method.
2207
Guido van Rossum051e3352001-01-15 19:11:10 +00002208- The xrange() object implementation has been improved so that
2209 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2210 limitation that in this case len(xrange(sys.maxint)) can't be
2211 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2212 work fine as long as the index i doesn't actually reach 2**31.
2213 (Python uses regular ints for sequence and string indices; fixing
2214 that is much more work.)
2215
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002216- Two changes to from...import:
2217
Guido van Rossumba381232001-02-03 15:06:40 +00002218 1) "from M import X" now works even if (after loading module M)
2219 sys.modules['M'] is not a real module; it's basically a getattr()
2220 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002221
2222 2) "from M import *" now looks for M.__all__ to decide which names to
2223 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2224 filters out names starting with '_' as before. Whether or not
2225 __all__ exists, there's no restriction on the type of M.
2226
Guido van Rossumf61f1662001-01-10 20:13:55 +00002227- File objects have a new method, xreadlines(). This is the fastest
2228 way to iterate over all lines in a file:
2229
2230 for line in file.xreadlines():
2231 ...do something to line...
2232
2233 See the xreadlines module (mentioned below) for how to do this for
2234 other file-like objects.
2235
2236- Even if you don't use file.xreadlines(), you may expect a speedup on
2237 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002238 quite a bit in platform-specific ways: on systems (like Linux) that
2239 support flockfile(), getc_unlocked(), and funlockfile(), those are
2240 used by default. On systems (like Windows) without getc_unlocked(),
2241 a complicated (but still thread-safe) method using fgets() is used by
2242 default.
2243
Tim Petersd52269b2001-01-25 06:23:18 +00002244 You can force use of the fgets() method by #define'ing
2245 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002246 getc_unlocked()).
2247
Tim Petersd52269b2001-01-25 06:23:18 +00002248 You can force fgets() not to be used by #define'ing
2249 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002250 test_bufio.py fails -- and let us know if it does!).
2251
2252- In addition, the fileinput module, while still slower than the other
2253 methods on most platforms, has been sped up too, by using
2254 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002255
2256- Support for run-time warnings has been added, including a new
2257 command line option (-W) to specify the disposition of warnings.
2258 See the description of the warnings module below.
2259
2260- Extensive changes have been made to the coercion code. This mostly
2261 affects extension modules (which can now implement mixed-type
2262 numerical operators without having to use coercion), but
2263 occasionally, in boundary cases the coercion semantics have changed
2264 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002265 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002266 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002267 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002268
Guido van Rossumf98eda02001-01-17 15:54:45 +00002269- In connection with the coercion changes, a new built-in singleton
2270 object, NotImplemented is defined. This can be returned for
2271 operations that wish to indicate they are not implemented for a
2272 particular combination of arguments. From C, this is
2273 Py_NotImplemented.
2274
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002275- The interpreter accepts now bytecode files on the command line even
2276 if they do not have a .pyc or .pyo extension. On Linux, after executing
2277
Martin v. Löwise214baa2001-02-04 22:37:56 +00002278import imp,sys,string
2279magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2280reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2281open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002282
2283 any byte code file can be used as an executable (i.e. as an argument
2284 to execve(2)).
2285
Tim Peters9940b802000-12-01 07:59:35 +00002286- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002287 character. In 1.6 and earlier, they never produced a sign,
2288 and raised an error if the value of the long was too large
2289 to fit in a Python int. In 2.0, they produced a sign if and
2290 only if too large to fit in an int. This was inconsistent
2291 across platforms (because the size of an int varies across
2292 platforms), and inconsistent with hex() and oct(). Example:
2293
2294 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002295 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002296 'ffffffbe' # in 2.0 and before, on 32-bit machines
2297 >>> hex(-0x42L)
2298 '-0x42L' # in all versions of Python
2299
Tim Peters9940b802000-12-01 07:59:35 +00002300 The behavior of %d formats for negative Python longs remains
2301 the same as in 2.0 (although in 1.6 and before, they raised
2302 an error if the long didn't fit in a Python int).
2303
2304 %u formats don't make sense for Python longs, but are allowed
2305 and treated the same as %d in 2.1. In 2.0, a negative long
2306 formatted via %u produced a sign if and only if too large to
2307 fit in an int. In 1.6 and earlier, a negative long formatted
2308 via %u raised an error if it was too big to fit in an int.
2309
Guido van Rossum3661d392000-12-12 22:10:31 +00002310- Dictionary objects have an odd new method, popitem(). This removes
2311 an arbitrary item from the dictionary and returns it (in the form of
2312 a (key, value) pair). This can be useful for algorithms that use a
2313 dictionary as a bag of "to do" items and repeatedly need to pick one
2314 item. Such algorithms normally end up running in quadratic time;
2315 using popitem() they can usually be made to run in linear time.
2316
Tim Peters36cdad12000-12-29 02:06:45 +00002317Standard library
2318
Thomas Woutersfe385252001-01-19 23:16:56 +00002319- In the time module, the time argument to the functions strftime,
2320 localtime, gmtime, asctime and ctime is now optional, defaulting to
2321 the current time (in the local timezone).
2322
Guido van Rossumda91f222001-01-15 16:36:08 +00002323- The ftplib module now defaults to passive mode, which is deemed a
2324 more useful default given that clients are often inside firewalls
2325 these days. Note that this could break if ftplib is used to connect
2326 to a *server* that is inside a firewall, from outside; this is
2327 expected to be a very rare situation. To fix that, you can call
2328 ftp.set_pasv(0).
2329
Martin v. Löwis10a27872001-01-13 09:54:41 +00002330- The module site now treats .pth files not only for path configuration,
2331 but also supports extensions to the initialization code: Lines starting
2332 with import are executed.
2333
Guido van Rossumf61f1662001-01-10 20:13:55 +00002334- There's a new module, warnings, which implements a mechanism for
2335 issuing and filtering warnings. There are some new built-in
2336 exceptions that serve as warning categories, and a new command line
2337 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2338 turns warnings into errors). warnings.warn(message[, category])
2339 issues a warning message; this can also be called from C as
2340 PyErr_Warn(category, message).
2341
2342- A new module xreadlines was added. This exports a single factory
2343 function, xreadlines(). The intention is that this code is the
2344 absolutely fastest way to iterate over all lines in an open
2345 file(-like) object:
2346
2347 import xreadlines
2348 for line in xreadlines.xreadlines(file):
2349 ...do something to line...
2350
2351 This is equivalent to the previous the speed record holder using
2352 file.readlines(sizehint). Note that if file is a real file object
2353 (as opposed to a file-like object), this is equivalent:
2354
2355 for line in file.xreadlines():
2356 ...do something to line...
2357
Tim Peters36cdad12000-12-29 02:06:45 +00002358- The bisect module has new functions bisect_left, insort_left,
2359 bisect_right and insort_right. The old names bisect and insort
2360 are now aliases for bisect_right and insort_right. XXX_right
2361 and XXX_left methods differ in what happens when the new element
2362 compares equal to one or more elements already in the list: the
2363 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002364 right. Code that doesn't care where equal elements end up should
2365 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002366
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002367- The new curses.panel module wraps the panel library that forms part
2368 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2369
Guido van Rossumf61f1662001-01-10 20:13:55 +00002370- The SocketServer module now sets the allow_reuse_address flag by
2371 default in the TCPServer class.
2372
2373- A new function, sys._getframe(), returns the stack frame pointer of
2374 the caller. This is intended only as a building block for
2375 higher-level mechanisms such as string interpolation.
2376
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002377- The pyexpat module supports a number of new handlers, which are
2378 available only in expat 1.2. If invocation of a callback fails, it
2379 will report an additional frame in the traceback. Parser objects
2380 participate now in garbage collection. If expat reports an unknown
2381 encoding, pyexpat will try to use a Python codec; that works only
2382 for single-byte charsets. The parser type objects is exposed as
2383 XMLParserObject.
2384
2385- xml.dom now offers standard definitions for symbolic node type and
2386 exception code constants, and a hierarchy of DOM exceptions. minidom
2387 was adjusted to use them.
2388
2389- The conformance of xml.dom.minidom to the DOM specification was
2390 improved. It detects a number of additional error cases; the
2391 previous/next relationship works even when the tree is modified;
2392 Node supports the normalize() method; NamedNodeMap, DocumentType and
2393 DOMImplementation classes were added; Element supports the
2394 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2395 method.
2396
Guido van Rossumf61f1662001-01-10 20:13:55 +00002397Build issues
2398
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002399- For Unix (and Unix-compatible) builds, configuration and building of
2400 extension modules is now greatly automated. Rather than having to
2401 edit the Modules/Setup file to indicate which modules should be
2402 built and where their include files and libraries are, a
2403 distutils-based setup.py script now takes care of building most
2404 extension modules. All extension modules built this way are built
2405 as shared libraries. Only a few modules that must be linked
2406 statically are still listed in the Setup file; you won't need to
2407 edit their configuration.
2408
2409- Python should now build out of the box on Cygwin. If it doesn't,
2410 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002411
2412- Python now always uses its own (renamed) implementation of getopt()
2413 -- there's too much variation among C library getopt()
2414 implementations.
2415
2416- C++ compilers are better supported; the CXX macro is always set to a
2417 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002418
Tim Petersd92dfe02000-12-12 01:18:41 +00002419Windows changes
2420
2421- select module: By default under Windows, a select() call
2422 can specify no more than 64 sockets. Python now boosts
2423 this Microsoft default to 512. If you need even more than
2424 that, see the MS docs (you'll need to #define FD_SETSIZE
2425 and recompile Python from source).
2426
Guido van Rossumf61f1662001-01-10 20:13:55 +00002427- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2428 subdirectory is no more!
2429
Tim Petersa3a3a032000-11-30 05:22:44 +00002430
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002431What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002432=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002433
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002434Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002435changes are in the file HISTORY. If you are making the jump directly
2436from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2437HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002438
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002439Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2440the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2441http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002442
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002443--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002444
2445======================================================================
2446
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002447What's new in 2.0 (since release candidate 1)?
2448==============================================
2449
2450Standard library
2451
2452- The copy_reg module was modified to clarify its intended use: to
2453 register pickle support for extension types, not for classes.
2454 pickle() will raise a TypeError if it is passed a class.
2455
2456- Fixed a bug in gettext's "normalize and expand" code that prevented
2457 it from finding an existing .mo file.
2458
2459- Restored support for HTTP/0.9 servers in httplib.
2460
Tim Peters989b7b92000-10-16 20:24:53 +00002461- The math module was changed to stop raising OverflowError in case of
2462 underflow, and return 0 instead in underflow cases. Whether Python
2463 used to raise OverflowError in case of underflow was platform-
2464 dependent (it did when the platform math library set errno to ERANGE
2465 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002466
2467- Fixed a bug in StringIO that occurred when the file position was not
2468 at the end of the file and write() was called with enough data to
2469 extend past the end of the file.
2470
2471- Fixed a bug that caused Tkinter error messages to get lost on
2472 Windows. The bug was fixed by replacing direct use of
2473 interp->result with Tcl_GetStringResult(interp).
2474
2475- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2476 redirect response.
2477
2478- Several changes were made to distutils: Some debugging code was
2479 removed from util. Fixed the installer used when an external zip
2480 program (like WinZip) is not found; the source code for this
2481 installer is in Misc/distutils. check_lib() was modified to behave
2482 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2483 test for whether installed modules are on sys.path was changed to
2484 use both normcase() and normpath().
2485
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002486- Several minor bugs were fixed in the xml package (the minidom,
2487 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002488
2489- The regression test driver (regrtest.py) behavior when invoked with
2490 -l changed: It now reports a count of objects that are recognized as
2491 garbage but not freed by the garbage collector.
2492
Tim Peters989b7b92000-10-16 20:24:53 +00002493- The regression test for the math module was changed to test
2494 exceptional behavior when the test is run in verbose mode. Python
2495 cannot yet guarantee consistent exception behavior across platforms,
2496 so the exception part of test_math is run only in verbose mode, and
2497 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002498
2499Internals
2500
2501- PyOS_CheckStack() has been disabled on Win64, where it caused
2502 test_sre to fail.
2503
2504Build issues
2505
2506- Changed compiler flags, so that gcc is always invoked with -Wall and
2507 -Wstrict-prototypes. Users compiling Python with GCC should see
2508 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002509 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002510 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002511
Tim Petersa3a3a032000-11-30 05:22:44 +00002512- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002513
2514Tools and other miscellany
2515
2516- The compiler in Tools/compiler was updated to support the new
2517 language features introduced in 2.0: extended print statement, list
2518 comprehensions, and augmented assignments. The new compiler should
2519 also be backwards compatible with Python 1.5.2; the compiler will
2520 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002521 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002522
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002523What's new in 2.0 release candidate 1 (since beta 2)?
2524=====================================================
2525
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002526What is release candidate 1?
2527
2528We believe that release candidate 1 will fix all known bugs that we
2529intend to fix for the 2.0 final release. This release should be a bit
2530more stable than the previous betas. We would like to see even more
2531widespread testing before the final release, so we are producing this
2532release candidate. The final release will be exactly the same unless
2533any show-stopping (or brown bag) bugs are found by testers of the
2534release candidate.
2535
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002536All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002537to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002538
2539Core language, builtins, and interpreter
2540
2541- A bug that caused crashes when __coerce__ was used with augmented
2542 assignment, e.g. +=, was fixed.
2543
2544- Raise ZeroDivisionError when raising zero to a negative number,
2545 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2546 power operator and the result of math.pow(0.0, -2.0) will vary by
2547 platform. On Linux, it raises a ValueError.
2548
2549- A bug in Unicode string interpolation was fixed that occasionally
2550 caused errors with formats including "%%". For example, the
2551 following expression "%% %s" % u"abc" no longer raises a TypeError.
2552
2553- Compilation of deeply nested expressions raises MemoryError instead
2554 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2555
2556- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2557 rendering them useless. They are now written in binary mode again.
2558
2559Standard library
2560
2561- Keyword arguments are now accepted for most pattern and match object
2562 methods in SRE, the standard regular expression engine.
2563
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002564- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002565 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002566
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002567- Several bugs in the Unicode handling and error handling in _tkinter
2568 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002569
2570- Fix memory management errors in Merge() and Tkapp_Call() routines.
2571
2572- Several changes were made to cStringIO to make it compatible with
2573 the file-like object interface and with StringIO. If operations are
2574 performed on a closed object, an exception is raised. The truncate
2575 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002576 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002577
2578- There were many changes made to the linuxaudiodev module and its
2579 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002580 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002581
2582 Note that this module is named poorly, because it should work
2583 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002584 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002585
2586 The module now raises exceptions when errors occur instead of
2587 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2588 audio) and defines a getptr() method that calls the
2589 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2590
2591- The library_version attribute, introduced in an earlier beta, was
2592 removed because it can not be supported with early versions of the C
2593 readline library, which provides no way to determine the version at
2594 compile-time.
2595
2596- The binascii module is now enabled on Win64.
2597
Tim Peters46446d62000-10-09 21:19:31 +00002598- tokenize.py no longer suffers "recursion depth" errors when parsing
2599 programs with very long string literals.
2600
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002601Internals
2602
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002603- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002604 which is called when the interpreter starts up to determine where
2605 the standard library is installed. These vulnerabilities affect all
2606 previous versions of Python and can be exploited by setting very
2607 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2608 setuid Python script, although use of the wrapper in
2609 Misc/setuid-prog.c will eliminate the vulnerability.
2610
2611- Fixed garbage collection bugs in instance creation that were
2612 triggered when errors occurred during initialization. The solution,
2613 applied in cPickle and in PyInstance_New(), is to call
2614 PyObject_GC_Init() after the initialization of the object's
2615 container attributes is complete.
2616
2617- pyexpat adds definitions of PyModule_AddStringConstant and
2618 PyModule_AddObject if the Python version is less than 2.0, which
2619 provides compatibility with PyXML on Python 1.5.2.
2620
2621- If the platform has a bogus definition for LONG_BIT (the number of
2622 bits in a long), an error will be reported at compile time.
2623
2624- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2625 collection crashes and possibly other, unreported crashes.
2626
2627- Fixed a memory leak in _PyUnicode_Fini().
2628
2629Build issues
2630
2631- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002632 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002633 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002634
2635- The mmap.PAGESIZE constant is now initialized using sysconf when
2636 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2637
2638- The md5 file should now compile on all platforms.
2639
2640- The select module now compiles on platforms that do not define
2641 POLLRDNORM and related constants.
2642
2643- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002644 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002645
Jeremy Hylton10921202000-10-09 18:34:12 +00002646- BeOS: A number of changes were made to the build and installation
2647 process. ar-fake now operates on a directory of object files.
2648 dl_export.h is gone, and its macros now appear on the mwcc command
2649 line during build on PPC BeOS.
2650
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002651- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002652 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002653
2654- Cygwin: Support for shared libraries, Tkinter, and sockets.
2655
2656- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2657
2658Tools and other miscellany
2659
2660- Removed debugging prints from main used with freeze.
2661
Tim Peters46446d62000-10-09 21:19:31 +00002662- IDLE auto-indent no longer crashes when it encounters Unicode
2663 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002664
2665What's new in 2.0 beta 2 (since beta 1)?
2666========================================
2667
2668Core language, builtins, and interpreter
2669
Tim Peters482c0212000-09-26 06:33:09 +00002670- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002671 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002672
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002673- Add -h and -V command line options to print the usage message and
2674 Python version number and exit immediately.
2675
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002676- eval() and exec accept Unicode objects as code parameters.
2677
2678- getattr() and setattr() now also accept Unicode objects for the
2679 attribute name, which are converted to strings using the default
2680 encoding before lookup.
2681
2682- Multiplication on string and Unicode now does proper bounds
2683 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2684 string is too long."
2685
2686- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002687 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002688
Jeremy Hylton1b618592000-09-26 05:32:36 +00002689
2690Standard library and extensions
2691
Guido van Rossum5b08f132001-04-16 02:05:23 +00002692- socket module: the OpenSSL code now adds support for RAND_status()
2693 and EGD (Entropy Gathering Device).
2694
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002695- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002696 argument checking; it still takes no arguments.
2697
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002698- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002699
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002700- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002701
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002702- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002703
2704- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002705 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002706
2707- copy: Copy Unicode objects atomically.
2708
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002709- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002710
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002711- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002712
Fred Drake67233bc2000-09-26 16:40:27 +00002713- dbm: Add get() and setdefault() methods to dbm object. Add constant
2714 `library' to module that names the library used. Added doc strings
2715 and method names to error messages. Uses configure to determine
2716 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2717 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718
2719- distutils: Update to version 0.9.3.
2720
2721- dl: Add several dl.RTLD_ constants.
2722
2723- fpectl: Now supported on FreeBSD.
2724
2725- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2726 found by the collector will be saved in gc.garbage. This is useful
2727 for debugging a program that creates reference cycles.
2728
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002729- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002730 of HTTP class. Do not close socket on zero-length response. Do not
2731 crash when server sends invalid content-length header.
2732
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002733- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002734
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002735- marshal: When reading a short, sign-extend on platforms where shorts
2736 are bigger than 16 bits. When reading a long, repair the unportable
2737 sign extension that was being done for 64-bit machines. (It assumed
2738 that signed right shift sign-extends.)
2739
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002740- operator: Add contains(), invert(), __invert__() as aliases for
2741 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002742
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002743- os: Add support for popen2() and popen3() on all platforms where
2744 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002745
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002746- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002747 clicking on a file in Explorer (or passing the file name to the
2748 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002749
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002750- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002751 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752
2753- pickle: Now raises ValueError when an invalid pickle that contains
2754 a non-string repr where a string repr was expected. This behavior
2755 matches cPickle.
2756
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002757- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002758
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002759- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002760
2761- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002762 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002763 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002764
2765- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002766 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002767
2768- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002769 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002770 few cycles during startup since the first call to
2771 setdefaultencoding() will initialize the codec registry and the
2772 encodings package.
2773
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002774- socket: Support for size hint in readlines() method of object returned
2775 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002776
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002777- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002778 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779 is followed by whitespace.
2780
Tim Petersa3a3a032000-11-30 05:22:44 +00002781- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002782
2783- struct: Check ranges for bytes and shorts.
2784
2785- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002786 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002787
2788- Tkinter: Image objects are now guaranteed to have unique ids. Set
2789 event.delta to zero if Tk version doesn't support mousewheel.
2790 Removed some debugging prints.
2791
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002792- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002793
Fred Drake67233bc2000-09-26 16:40:27 +00002794- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002795 which works around a bug in Norton AntiVirus 2000 that leads directly
2796 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002797
2798- xml: New version detection code allows PyXML to override standard
2799 XML package if PyXML version is greater than 0.6.1.
2800
Fred Drake64bb3802000-09-26 16:21:35 +00002801- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2802 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2803 tree only for nodes which are sufficiently interesting to a specific
2804 application. Does not provide the HTML-specific extensions. Still
2805 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002806
Fred Drake64bb3802000-09-26 16:21:35 +00002807- xml.sax: SAX 2 support for Python, including all the handler
2808 interfaces needed to process XML 1.0 compliant XML. Some
2809 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002810
Fred Drake64bb3802000-09-26 16:21:35 +00002811- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2812 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002813
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002814
Jeremy Hylton1b618592000-09-26 05:32:36 +00002815C API
2816
2817- Add three new convenience functions for module initialization --
2818 PyModule_AddObject(), PyModule_AddIntConstant(), and
2819 PyModule_AddStringConstant().
2820
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002821- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002822 removed and add #error to Python.h if NULL isn't defined after
2823 #include of stdio.h.
2824
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002825- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002826 backwards compatibility (at the source level) with old extensions.
2827
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002828- A wrapper API was added for signal() and sigaction(). Instead of
2829 either function, always use PyOS_getsig() to get a signal handler
2830 and PyOS_setsig() to set one. A new convenience typedef
2831 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002832
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002833- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002834 internal data buffer and size of a string object -- or the default
2835 encoded version of a Unicode object.
2836
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002837- PyString_Size() and PyString_AsString() accept Unicode objects.
2838
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002839- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002840 exists). INT_MAX and LONG_MAX will always be defined, even if
2841 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002842
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002843- PyFloat_FromString takes a second argument, pend, that was
2844 effectively useless. It is now officially useless but preserved for
2845 backwards compatibility. If the pend argument is not NULL, *pend is
2846 set to NULL.
2847
2848- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2849 for the attribute name. See note on getattr() above.
2850
2851- A few bug fixes to argument processing for Unicode.
2852 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2853 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2854 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002855 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002856
2857- Py_BuildValue accepts B format (for bgen-generated code).
2858
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002859
Jeremy Hylton1b618592000-09-26 05:32:36 +00002860Internals
2861
2862- On Unix, fix code for finding Python installation directory so that
2863 it works when argv[0] is a relative path.
2864
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002865- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002866 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002867 rather than by generating a copy of the object.
2868
Tim Peters482c0212000-09-26 06:33:09 +00002869- Several of the internal Unicode tables are much smaller now, and
2870 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002871
Jeremy Hylton97693b02000-09-26 17:42:51 +00002872- In the garbage collector: Fixed bug in collection of tuples. Fixed
2873 bug that caused some instances to be removed from the container set
2874 while they were still live. Fixed parsing in gc.set_debug() for
2875 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002876
2877- Fixed refcount problem in instance deallocation that only occurred
2878 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2879
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002880- On Windows, getpythonregpath is now protected against null data in
2881 registry key.
2882
2883- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002884 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002885
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002886
Jeremy Hylton1b618592000-09-26 05:32:36 +00002887Build and platform-specific issues
2888
2889- Better support of GNU Pth via --with-pth configure option.
2890
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002891- Python/C API now properly exposed to dynamically-loaded extension
2892 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002893
2894- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2895 Don't define MS_SYNC to be zero when it is undefined. Added missing
2896 prototypes in posixmodule.c.
2897
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002898- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002899 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002900
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002901- Fix largefile support on older NetBSD systems and OpenBSD by adding
2902 define for TELL64.
2903
2904
2905Tools and other miscellany
2906
2907- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2908
2909- freeze: The modulefinder now works with 2.0 opcodes.
2910
Tim Petersa3a3a032000-11-30 05:22:44 +00002911- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002912 Move hackery of sys.argv until after the Tk instance has been
2913 created, which allows the application-specific Tkinter
2914 initialization to be executed if present; also pass an explicit
2915 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002916
Jeremy Hylton1b618592000-09-26 05:32:36 +00002917
2918What's new in 2.0 beta 1?
2919=========================
2920
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002921Source Incompatibilities
2922------------------------
2923
2924None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2925such as single-argument append(), connect() and bind(), and changes to
2926str(long) and repr(float).
2927
2928
2929Binary Incompatibilities
2930------------------------
2931
2932- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2933with Python 2.0; these extensions will have to be rebuilt for Python
29342.0.
2935
2936- On Windows, attempting to import a third party extension built for
2937Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2938can do about this. Check your PYTHONPATH environment variable!
2939
2940- Python bytecode files (*.pyc and *.pyo) are not compatible between
2941releases.
2942
2943
2944Overview of Changes Since 1.6
2945-----------------------------
2946
2947There are many new modules (including brand new XML support through
2948the xml package, and i18n support through the gettext module); a list
2949of all new modules is included below. Lots of bugs have been fixed.
2950
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002951The process for making major new changes to the language has changed
2952since Python 1.6. Enhancements must now be documented by a Python
2953Enhancement Proposal (PEP) before they can be accepted.
2954
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002955There are several important syntax enhancements, described in more
2956detail below:
2957
2958 - Augmented assignment, e.g. x += 1
2959
2960 - List comprehensions, e.g. [x**2 for x in range(10)]
2961
2962 - Extended import statement, e.g. import Module as Name
2963
2964 - Extended print statement, e.g. print >> file, "Hello"
2965
2966Other important changes:
2967
2968 - Optional collection of cyclical garbage
2969
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002970Python Enhancement Proposal (PEP)
2971---------------------------------
2972
2973PEP stands for Python Enhancement Proposal. A PEP is a design
2974document providing information to the Python community, or describing
2975a new feature for Python. The PEP should provide a concise technical
2976specification of the feature and a rationale for the feature.
2977
2978We intend PEPs to be the primary mechanisms for proposing new
2979features, for collecting community input on an issue, and for
2980documenting the design decisions that have gone into Python. The PEP
2981author is responsible for building consensus within the community and
2982documenting dissenting opinions.
2983
2984The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002985
2986Augmented Assignment
2987--------------------
2988
2989This must have been the most-requested feature of the past years!
2990Eleven new assignment operators were added:
2991
Guido van Rossume905e952000-09-05 12:42:46 +00002992 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002993
2994For example,
2995
2996 A += B
2997
2998is similar to
2999
3000 A = A + B
3001
3002except that A is evaluated only once (relevant when A is something
3003like dict[index].attr).
3004
3005However, if A is a mutable object, A may be modified in place. Thus,
3006if A is a number or a string, A += B has the same effect as A = A+B
3007(except A is only evaluated once); but if a is a list, A += B has the
3008same effect as A.extend(B)!
3009
3010Classes and built-in object types can override the new operators in
3011order to implement the in-place behavior; the not-in-place behavior is
3012used automatically as a fallback when an object doesn't implement the
3013in-place behavior. For classes, the method name is derived from the
3014method name for the corresponding not-in-place operator by inserting
3015an 'i' in front of the name, e.g. __iadd__ implements in-place
3016__add__.
3017
3018Augmented assignment was implemented by Thomas Wouters.
3019
3020
3021List Comprehensions
3022-------------------
3023
3024This is a flexible new notation for lists whose elements are computed
3025from another list (or lists). The simplest form is:
3026
3027 [<expression> for <variable> in <sequence>]
3028
Guido van Rossum56db0952000-09-06 23:34:25 +00003029For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003030This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003031
3032You can also add a condition:
3033
3034 [<expression> for <variable> in <sequence> if <condition>]
3035
3036For example, [w for w in words if w == w.lower()] would yield the list
3037of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003038than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003039
3040You can also have nested for loops and more than one 'if' clause. For
3041example, here's a function that flattens a sequence of sequences::
3042
3043 def flatten(seq):
3044 return [x for subseq in seq for x in subseq]
3045
3046 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3047
3048This prints
3049
3050 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3051
3052List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003053Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003054
3055
3056Extended Import Statement
3057-------------------------
3058
3059Many people have asked for a way to import a module under a different
3060name. This can be accomplished like this:
3061
3062 import foo
3063 bar = foo
3064 del foo
3065
3066but this common idiom gets old quickly. A simple extension of the
3067import statement now allows this to be written as follows:
3068
3069 import foo as bar
3070
3071There's also a variant for 'from ... import':
3072
3073 from foo import bar as spam
3074
3075This also works with packages; e.g. you can write this:
3076
3077 import test.regrtest as regrtest
3078
3079Note that 'as' is not a new keyword -- it is recognized only in this
3080context (this is only possible because the syntax for the import
3081statement doesn't involve expressions).
3082
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003083Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003084
3085
3086Extended Print Statement
3087------------------------
3088
3089Easily the most controversial new feature, this extension to the print
3090statement adds an option to make the output go to a different file
3091than the default sys.stdout.
3092
3093For example, to write an error message to sys.stderr, you can now
3094write:
3095
3096 print >> sys.stderr, "Error: bad dog!"
3097
3098As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003099evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003100
3101 print >> None, "Hello world"
3102
3103is equivalent to
3104
3105 print "Hello world"
3106
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003107Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003108
3109
3110Optional Collection of Cyclical Garbage
3111---------------------------------------
3112
3113Python is now equipped with a garbage collector that can hunt down
3114cyclical references between Python objects. It's no replacement for
3115reference counting; in fact, it depends on the reference counts being
3116correct, and decides that a set of objects belong to a cycle if all
3117their reference counts can be accounted for from their references to
3118each other. This devious scheme was first proposed by Eric Tiedemann,
3119and brought to implementation by Neil Schemenauer.
3120
3121There's a module "gc" that lets you control some parameters of the
3122garbage collection. There's also an option to the configure script
3123that lets you enable or disable the garbage collection. In 2.0b1,
3124it's on by default, so that we (hopefully) can collect decent user
3125experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003126performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003127off by default in the final 2.0 release.
3128
3129
3130Smaller Changes
3131---------------
3132
3133A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3134map(None, seq1, seq2, ...) when the sequences have the same length;
3135i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3136the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003137zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003138
3139sys.version_info is a tuple (major, minor, micro, level, serial).
3140
3141Dictionaries have an odd new method, setdefault(key, default).
3142dict.setdefault(key, default) returns dict[key] if it exists; if not,
3143it sets dict[key] to default and returns that value. Thus:
3144
3145 dict.setdefault(key, []).append(item)
3146
3147does the same work as this common idiom:
3148
3149 if not dict.has_key(key):
3150 dict[key] = []
3151 dict[key].append(item)
3152
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003153There are two new variants of SyntaxError that are raised for
3154indentation-related errors: IndentationError and TabError.
3155
3156Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3157escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003158
3159The limits on the size of expressions and file in Python source code
3160have been raised from 2**16 to 2**32. Previous versions of Python
3161were limited because the maximum argument size the Python VM accepted
3162was 2**16. This limited the size of object constructor expressions,
3163e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3164limit was raised thanks to a patch by Charles Waldman that effectively
3165fixes the problem. It is now much more likely that you will be
3166limited by available memory than by an arbitrary limit in Python.
3167
3168The interpreter's maximum recursion depth can be modified by Python
3169programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3170limit is the maximum number of recursive calls that can be made by
3171Python code. The limit exists to prevent infinite recursion from
3172overflowing the C stack and causing a core dump. The default value is
31731000. The maximum safe value for a particular platform can be found
3174by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003175
3176New Modules and Packages
3177------------------------
3178
3179atexit - for registering functions to be called when Python exits.
3180
3181imputil - Greg Stein's alternative API for writing custom import
3182hooks.
3183
3184pyexpat - an interface to the Expat XML parser, contributed by Paul
3185Prescod.
3186
3187xml - a new package with XML support code organized (so far) in three
3188subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3189would fill a volume. There's a special feature whereby a
3190user-installed package named _xmlplus overrides the standard
3191xmlpackage; this is intended to give the XML SIG a hook to distribute
3192backwards-compatible updates to the standard xml package.
3193
3194webbrowser - a platform-independent API to launch a web browser.
3195
3196
Guido van Rossume905e952000-09-05 12:42:46 +00003197Changed Modules
3198---------------
3199
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003200array -- new methods for array objects: count, extend, index, pop, and
3201remove
3202
3203binascii -- new functions b2a_hex and a2b_hex that convert between
3204binary data and its hex representation
3205
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003206calendar -- Many new functions that support features including control
3207over which day of the week is the first day, returning strings instead
3208of printing them. Also new symbolic constants for days of week,
3209e.g. MONDAY, ..., SUNDAY.
3210
3211cgi -- FieldStorage objects have a getvalue method that works like a
3212dictionary's get method and returns the value attribute of the object.
3213
3214ConfigParser -- The parser object has new methods has_option,
3215remove_section, remove_option, set, and write. They allow the module
3216to be used for writing config files as well as reading them.
3217
3218ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003219optionally support the RFC 959 REST command.
3220
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003221gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003222
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003223httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3224the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003225
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003226locale -- implement getdefaultlocale for Win32 and Macintosh
3227
3228marshal -- no longer dumps core when marshaling deeply nested or
3229recursive data structures
3230
3231os -- new functions isatty, seteuid, setegid, setreuid, setregid
3232
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003233os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3234support under Unix.
3235
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003236os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003237
3238os.path -- fix semantics of os.path.commonprefix
3239
3240smtplib -- support for sending very long messages
3241
3242socket -- new function getfqdn()
3243
3244readline -- new functions to read, write and truncate history files.
3245The readline section of the library reference manual contains an
3246example.
3247
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003248select -- add interface to poll system call
3249
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003250shutil -- new copyfileobj function
3251
3252SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3253HTTP server.
3254
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003255Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003256
3257urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003258e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003259
3260whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003261
3262
3263Obsolete Modules
3264----------------
3265
3266None. However note that 1.6 made a whole slew of modules obsolete:
3267stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3268poly, zmod, strop, util, whatsound.
3269
3270
3271Changed, New, Obsolete Tools
3272----------------------------
3273
Tim Peters8b092332000-09-05 20:15:25 +00003274None.
Guido van Rossume905e952000-09-05 12:42:46 +00003275
3276
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003277C-level Changes
3278---------------
3279
3280Several cleanup jobs were carried out throughout the source code.
3281
3282All C code was converted to ANSI C; we got rid of all uses of the
3283Py_PROTO() macro, which makes the header files a lot more readable.
3284
3285Most of the portability hacks were moved to a new header file,
3286pyport.h; several other new header files were added and some old
3287header files were removed, in an attempt to create a more rational set
3288of header files. (Few of these ever need to be included explicitly;
3289they are all included by Python.h.)
3290
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003291Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003292and Win64, especially for the new Intel Itanium processor. Mick also
3293added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003294
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003295The C APIs to return an object's size have been update to consistently
3296use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3297previous versions, the abstract interfaces used PyXXX_Length and the
3298concrete interfaces used PyXXX_Size. The old names,
3299e.g. PyObject_Length, are still available for backwards compatibility
3300at the API level, but are deprecated.
3301
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003302The PyOS_CheckStack function has been implemented on Windows by
3303Fredrik Lundh. It prevents Python from failing with a stack overflow
3304on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003305
3306The GC changes resulted in creation of two new slots on object,
3307tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003308the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003309
3310The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003311C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003312
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003313PyErr_Format has been updated to automatically calculate the size of
3314the buffer needed to hold the formatted result string. This change
3315prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003316
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003317New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003318
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003319PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3320that are the same as their non-Ex counterparts except they take an
3321extra flag argument that tells them to close the file when done.
3322
3323XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003324
Tim Peters8b092332000-09-05 20:15:25 +00003325
3326Windows Changes
3327---------------
3328
3329New popen2/popen3/peopen4 in os module (see Changed Modules above).
3330
3331os.popen is much more usable on Windows 95 and 98. See Microsoft
3332Knowledge Base article Q150956. The Win9x workaround described there
3333is implemented by the new w9xpopen.exe helper in the root of your
3334Python installation. Note that Python uses this internally; it is not
3335a standalone program.
3336
3337Administrator privileges are no longer required to install Python
3338on Windows NT or Windows 2000. If you have administrator privileges,
3339Python's registry info will be written under HKEY_LOCAL_MACHINE.
3340Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003341under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003342uses of Python, but will prevent some advanced uses from working
3343(for example, running a Python script as an NT service, or possibly
3344from CGI).
3345
3346[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3347installer; instead, it installs the needed Tcl/Tk files directly in the
3348Python directory. If you already have a Tcl/Tk installation, this
3349wastes some disk space (about 4 Megs) but avoids problems with
3350conflicting Tcl/Tk installations, and makes it much easier for Python
3351to ensure that Tcl/Tk can find all its files.
3352
3353[This was new in 1.6] The Windows installer now installs by default in
3354\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3355
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003356
3357Updates to the changes between 1.5.2 and 1.6
3358--------------------------------------------
3359
3360The 1.6 NEWS file can't be changed after the release is done, so here
3361is some late-breaking news:
3362
3363New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3364and changes to getlocale() and setlocale().
3365
3366The new module is now enabled per default.
3367
3368It is not true that the encodings codecs cannot be used for normal
3369strings: the string.encode() (which is also present on 8-bit strings
3370!) allows using them for 8-bit strings too, e.g. to convert files from
3371cp1252 (Windows) to latin-1 or vice-versa.
3372
3373Japanese codecs are available from Tamito KAJIYAMA:
3374http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3375
3376
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003377======================================================================