blob: c2622f8ec913b1d8bc17fdc5770e8ab057b521f7 [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 Rossum47834462002-04-04 15:21:33 +00009- A new built-in type, bool, has been added, as well as built-in
10 names for its two values, True and False. Comparisons and sundry
11 other operations that return a truth value have been changed to
12 return a bool instead. Read PEP 285 for an explanantion of why this
13 is backward compatible.
14
Guido van Rossum95b62a62002-03-29 01:07:24 +000015- Fixed two bugs reported as SF #535905: under certain conditions,
16 deallocating a deeply nested structure could cause a segfault in the
17 garbage collector, due to interaction with the "trashcan" code;
18 access to the current frame during destruction of a local variable
19 could access a pointer to freed memory.
20
Neil Schemenauer9d50d132002-03-22 17:06:59 +000021- The optional object allocator has been enabled by default.
22
Guido van Rossum8c842552002-03-14 23:05:54 +000023- If you try to pickle an instance of a class that has __slots__ but
24 doesn't define or override __getstate__, a TypeError is now raised.
25 This is done by adding a bozo __getstate__ to the class that always
26 raises TypeError. (Before, this would appear to be pickled, but the
27 state of the slots would be lost.)
28
Martin v. Löwiscfeb3b62002-03-03 21:30:27 +000029- PyErr_Display will provide file and line information for all exceptions
30 that have an attribute print_file_and_line, not just SyntaxErrors.
31
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000032- The UTF-8 codec will now encode and decode Unicode surrogates
33 correctly and without raising exceptions for unpaired ones.
34
Neal Norwitz649b7592002-01-01 19:07:13 +000035- file.xreadlines() now raises a ValueError if the file is closed:
36 Previously, an xreadlines object was returned which would raise
37 a ValueError when the xreadlines.next() method was called.
38
Martin v. Löwisb2c92f42002-02-16 23:35:41 +000039- posix.killpg has been added where available.
40
Neal Norwitz0c766a02002-03-27 13:03:09 +000041- sys.exit() inadvertantly allowed more than one argument.
42 An exception will now be raised if more than one argument is used.
43
Tim Petersaf8446f2001-12-21 21:36:50 +000044Extension modules
45
Martin v. Löwis2e64c342002-03-27 18:49:02 +000046- The locale module now exposes the C library's gettext interface.
47
Tim Petersfbf74f22002-03-14 19:06:01 +000048- A security hole ("double free") was found in zlib-1.1.3, a popular
49 third party compression library used by some Python modules. The
50 hole was quickly plugged in zlib-1.1.4, and the Windows build of
51 Python now ships with zlib-1.1.4.
52
Martin v. Löwis29001ff2002-03-01 10:47:37 +000053- pwd and grp return enhanced tuples now, with symbolic field names.
54
Martin v. Löwis99866332002-03-01 10:27:01 +000055- array.array is now a type object. A new format character
56 'u' indicates Py_UNICODE arrays. For those, .tounicode and
57 .fromunicode methods are available. Arrays now support __iadd__
58 and __imul__.
59
Neal Norwitze790eae2002-01-01 21:14:12 +000060- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000061 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
62 is called.
63
Tim Petersaf8446f2001-12-21 21:36:50 +000064Library
65
Martin v. Löwis5c137c22002-03-18 12:44:08 +000066- compileall now supports quiet operation.
67
Martin v. Löwis587c98c2002-03-17 18:37:22 +000068- The BaseHTTPServer implements now optionally HTTP/1.1 persistent
69 connections.
70
Marc-André Lemburga5d2b4c2002-02-16 18:23:30 +000071- socket module: the SSL support was broken out of the main
72 _socket module C helper and placed into a new _ssl helper
73 which now gets imported by socket.py if available and working.
74
Marc-André Lemburg37aa5802002-02-10 21:42:47 +000075- encodings package: added aliases for all supported IANA character
76 sets
77
Guido van Rossum606fe4e2001-12-28 20:57:14 +000078- ftplib: to safeguard the user's privacy, anonymous login will use
79 "anonymous@" as default password, rather than the real user and host
80 name.
81
Fred Drake36736122002-01-10 13:50:31 +000082- webbrowser: tightened up the command passed to os.system() so that
83 arbitrary shell code can't be executed because a bogus URL was
84 passed in.
85
Tim Peters11bd9942002-02-01 00:52:29 +000086- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000087 gettext.find an optional all argument. Translations will now fallback
88 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000089
Martin v. Löwis9668b932002-01-12 11:27:42 +000090- distutils bdist commands now offer a --skip-build option.
91
Walter Dörwaldb25c2b02002-03-21 10:38:40 +000092- warnings.warn now accepts a Warning instance as first argument.
93
Tim Petersaf8446f2001-12-21 21:36:50 +000094Tools/Demos
95
96Build
97
Martin v. Löwis1142de32002-03-29 16:28:31 +000098- On Unix, a shared libpython2.3.so can be created with --enable-shared.
99
Tim Peters8deda702002-03-30 10:06:07 +0000100- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
101 preprocessor symbols were eliminated. The internal decisions they
102 controlled stopped being experimental long ago.
Tim Peters1f7df352002-03-29 03:29:08 +0000103
Tim Petersaf8446f2001-12-21 21:36:50 +0000104C API
105
Neil Schemenauer9d50d132002-03-22 17:06:59 +0000106- Objects allocated using the new PyMalloc_New and PyMalloc_NewVar
107 functions will be allocated using pymalloc if it is enabled. These
108 objects should be deallocated using PyMalloc_Del. The PyObject_{New,
109 NewVar,NEW_VAR,Del,DEL} APIs have been changed to always use
110 PyMem_MALLOC and PyMem_FREE, even if pymalloc is enabled. The
111 PyCore_* family of APIs have been removed.
112
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +0000113- The "u#" parser marker will now pass through Unicode object as-is
114 without going through the buffer API.
115
Martin v. Löwis7198a522002-01-01 19:59:11 +0000116- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
117
Tim Peters10a3bb52001-12-25 19:07:38 +0000118- An old #define of ANY as void has been removed from pyport.h. This
119 hasn't been used since Python's pre-ANSI days, and the #define has
120 been marked as obsolete since then. SF bug 495548 says it created
121 conflicts with other packages, so keeping it around wasn't harmless.
122
Tim Petersaf8446f2001-12-21 21:36:50 +0000123- Because Python's magic number scheme broke on January 1st, we decided
124 to stop Python development. Thanks for all the fish!
125
Tim Petersfb05db22002-03-11 00:24:00 +0000126- Some of us don't like fish, so we changed Python's magic number
Marc-André Lemburge92e0a92002-02-09 11:28:43 +0000127 scheme to a new one. See Python/import.c for details.
128
Tim Petersaf8446f2001-12-21 21:36:50 +0000129New platforms
130
Martin v. Löwisa6e97582002-01-01 18:41:33 +0000131- GNU/Hurd is now supported.
132
Tim Petersaf8446f2001-12-21 21:36:50 +0000133Tests
134
135Windows
136
Tim Petersfb05db22002-03-11 00:24:00 +0000137- file.truncate([newsize]) now works on Windows for all newsize values.
138 It used to fail if newsize didn't fit in 32 bits, reflecting a
139 limitation of MS _chsize (which is no longer used).
140
Tim Petersab034fa2002-02-01 11:27:43 +0000141- os.waitpid() is now implemented for Windows, and can be used to block
142 until a specified process exits. This is similar to, but not exactly
143 the same as, os.waitpid() on POSIX systems. If you're waiting for
144 a specific process whose pid was obtained from one of the spawn()
145 functions, the same Python os.waitpid() code works across platforms.
146 See the docs for details.
147
Tim Peters11bd9942002-02-01 00:52:29 +0000148- New tempfile.TemporaryFile implementation for Windows: this doesn't
149 need a TemproraryFileWrapper wrapper anymore, and should be immune
150 to a nasty problem: before 2.3, if you got a temp file on Windows, it
151 got wrapped in an object whose close() method first closed the
152 underlying file, then deleted the file. This usually worked fine.
153 However, the spawn family of functions on Windows create (at a low C
154 level) the same set of open files in the spawned process Q as were
155 open in the spawning process P. If a temp file f was among them, then
156 doing f.close() in P first closed P's C-level file handle on f, but Q's
157 C-level file handle on f remained open, so the attempt in P to delete f
158 blew up with a "Permission denied" error (Windows doesn't allow
159 deleting open files). This was surprising, subtle, and difficult to
160 work around.
161
162- The os module now exports all the symbolic constants usable with the
163 low-level os.open() on Windows: the new constants in 2.3 are
164 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
165 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
166 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
167 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
168 (so specify both if you want both; note that neither is useful unless
169 specified with O_CREAT too).
170
Tim Petersaf8446f2001-12-21 21:36:50 +0000171Mac
172
173
Tim Peters909c0912001-12-14 23:16:18 +0000174What's New in Python 2.2 final?
175Release date: 21-Dec-2001
176===============================
177
178Type/class unification and new-style classes
179
Barry Warsaw52acb492001-12-21 20:04:22 +0000180- pickle.py, cPickle: allow pickling instances of new-style classes
181 with a custom metaclass.
182
Tim Peters909c0912001-12-14 23:16:18 +0000183Core and builtins
184
Barry Warsaw52acb492001-12-21 20:04:22 +0000185- weakref proxy object: when comparing, unwrap both arguments if both
186 are proxies.
187
Tim Peters909c0912001-12-14 23:16:18 +0000188Extension modules
189
Barry Warsaw52acb492001-12-21 20:04:22 +0000190- binascii.b2a_base64(): fix a potential buffer overrun when encoding
191 very short strings.
192
193- cPickle: the obscure "fast" mode was suspected of causing stack
194 overflows on the Mac. Hopefully fixed this by setting the recursion
195 limit much smaller. If the limit is too low (it only affects
196 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
197 when compiling cPickle.c (or in pyconfig.h).
198
Tim Peters909c0912001-12-14 23:16:18 +0000199Library
200
Barry Warsaw52acb492001-12-21 20:04:22 +0000201- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
202 close or delete time).
203
204- rfc822.py: fixed a bug where the address '<>' was converted to None
205 instead of an empty string (also fixes the email.Utils module).
206
207- xmlrpclib.py: version 1.0.0; uses precision for doubles.
208
209- test suite: the pickle and cPickle tests were not executing any code
210 when run from the standard regresssion test.
211
Tim Peters909c0912001-12-14 23:16:18 +0000212Tools/Demos
213
214Build
215
216C API
217
218New platforms
219
220Tests
221
222Windows
223
Barry Warsaw52acb492001-12-21 20:04:22 +0000224- distutils package: fixed broken Windows installers (bdist_wininst).
225
226- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
227 instances are deleted at process exit time.
228
229- socket.py: prevent mysterious warnings when socket instances are
230 deleted at process exit time.
231
232- posixmodule.c: fix a Windows crash with stat() of a filename ending
233 in backslash.
234
Tim Peters909c0912001-12-14 23:16:18 +0000235Mac
236
Barry Warsaw52acb492001-12-21 20:04:22 +0000237- The Carbon toolbox modules have been upgraded to Universal Headers
238 3.4, and experimental CoreGraphics and CarbonEvents modules have
239 been added. All only for framework-enabled MacOSX.
240
Tim Peters909c0912001-12-14 23:16:18 +0000241
Tim Peters6272dfd2001-12-13 19:34:00 +0000242What's New in Python 2.2c1?
243Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000244===========================
245
246Type/class unification and new-style classes
247
Barry Warsaw06557452001-12-14 20:47:12 +0000248- Guido's tutorial introduction to the new type/class features has
249 been extensively updated. See
250
251 http://www.python.org/2.2/descrintro.html
252
253 That remains the primary documentation in this area.
254
Guido van Rossum33bab012001-12-05 22:45:48 +0000255- Fixed a leak: instance variables declared with __slots__ were never
256 deleted!
257
Guido van Rossum4b800852001-12-03 00:54:52 +0000258- The "delete attribute" method of descriptor objects is called
259 __delete__, not __del__. In previous releases, it was mistakenly
260 called __del__, which created an unfortunate overloading condition
261 with finalizers. (The "get attribute" and "set attribute" methods
262 are still called __get__ and __set__, respectively.)
263
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000264- Some subtle issues with the super built-in were fixed:
265
266 (a) When super itself is subclassed, its __get__ method would still
267 return an instance of the base class (i.e., of super).
268
269 (b) super(C, C()).__class__ would return C rather than super. This
270 is confusing. To fix this, I decided to change the semantics of
271 super so that it only applies to code attributes, not to data
272 attributes. After all, overriding data attributes is not
273 supported anyway.
274
275 (c) The __get__ method didn't check whether the argument was an
276 instance of the type used in creation of the super instance.
277
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000278- Previously, hash() of an instance of a subclass of a mutable type
279 (list or dictionary) would return some value, rather than raising
280 TypeError. This has been fixed. Also, directly calling
281 dict.__hash__ and list.__hash__ now raises the same TypeError
282 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000283
Guido van Rossumd331cb52001-12-05 19:46:42 +0000284- New-style objects now support deleting their __dict__. This is for
285 all intents and purposes equivalent to assigning a brand new empty
286 dictionary, but saves space if the object is not used further.
287
Tim Petersb3c9af12001-11-17 00:21:57 +0000288Core and builtins
289
Tim Peters3caca232001-12-06 06:23:26 +0000290- -Qnew now works as documented in PEP 238: when -Qnew is passed on
291 the command line, all occurrences of "/" use true division instead
292 of classic division. See the PEP for details. Note that "all"
293 means all instances in library and 3rd-party modules, as well as in
294 your own code. As the PEP says, -Qnew is intended for use only in
295 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000296 Note that test_coercion.py in the standard Python test suite fails
297 under -Qnew; this is expected, and won't be repaired until true
298 division becomes the default (in the meantime, test_coercion is
299 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000300
Fred Drake6c01e252001-12-14 17:08:12 +0000301- complex() now only allows the first argument to be a string
302 argument, and raises TypeError if either the second arg is a string
303 or if the second arg is specified when the first is a string.
304
Tim Petersb3c9af12001-11-17 00:21:57 +0000305Extension modules
306
Martin v. Löwis560da622001-11-24 09:24:51 +0000307- gc.get_referents was renamed to gc.get_referrers.
308
Tim Petersb3c9af12001-11-17 00:21:57 +0000309Library
310
Tim Peters25059d32001-12-07 20:35:43 +0000311- Functions in the os.spawn() family now release the global interpreter
312 lock around calling the platform spawn. They should always have done
313 this, but did not before 2.2c1. Multithreaded programs calling
314 an os.spawn function with P_WAIT will no longer block all Python threads
315 until the spawned program completes. It's possible that some programs
316 relies on blocking, although more likely by accident than by design.
317
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000318- webbrowser defaults to netscape.exe on OS/2 now.
319
Martin v. Löwis652e1912001-11-25 14:50:56 +0000320- Tix.ResizeHandle exposes detach_widget, hide, and show.
321
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000322- The charset alias windows_1252 has been added.
323
Barry Warsaw06557452001-12-14 20:47:12 +0000324- types.StringTypes is a tuple containing the defined string types;
325 usually this will be (str, unicode), but if Python was compiled
326 without Unicode support it will be just (str,).
327
328- The pulldom and minidom modules were synchronized to PyXML.
329
Tim Petersb3c9af12001-11-17 00:21:57 +0000330Tools/Demos
331
Barry Warsaw06557452001-12-14 20:47:12 +0000332- A new script called Tools/scripts/google.py was added, which fires
333 off a search on Google.
334
Tim Petersb3c9af12001-11-17 00:21:57 +0000335Build
336
Barry Warsaw06557452001-12-14 20:47:12 +0000337- Note that release builds of Python should arrange to define the
338 preprocessor symbol NDEBUG on the command line (or equivalent).
339 In the 2.2 pre-release series we tried to define this by magic in
340 Python.h instead, but it proved to cause problems for extension
341 authors. The Unix, Windows and Mac builds now all define NDEBUG in
342 release builds via cmdline (or equivalent) instead. Ports to
343 other platforms should do likewise.
344
Jack Jansen1999ef42001-12-06 21:47:20 +0000345- It is no longer necessary to use --with-suffix when building on a
346 case-insensitive file system (such as Mac OS X HFS+). In the build
347 directory an extension is used, but not in the installed python.
348
Tim Petersb3c9af12001-11-17 00:21:57 +0000349C API
350
Tim Petersf582b822001-12-11 18:51:08 +0000351- New function PyDict_MergeFromSeq2() exposes the builtin dict
352 constructor's logic for updating a dictionary from an iterable object
353 producing key-value pairs.
354
Tim Peterscffed4b2001-11-29 03:26:37 +0000355- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000356 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000357 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
358 dump core in some bad cases. This has been repaired. As a result,
359 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
360 previously went unchallenged.
361
Tim Petersb3c9af12001-11-17 00:21:57 +0000362New platforms
363
364Tests
365
366Windows
367
368Mac
369
Jack Jansenffa260f2001-12-06 21:14:00 +0000370- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
371 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000372
Barry Warsaw06557452001-12-14 20:47:12 +0000373- Changed logic for finding python home in Mac OS X framework Pythons.
374 Now sys.executable points to the executable again, in stead of to
375 the shared library. The latter is used only for locating the python
376 home.
377
378
Tim Peters84362bc2001-10-19 17:55:30 +0000379What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000380Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000381===========================
382
383Type/class unification and new-style classes
384
Guido van Rossum3d27df02001-11-15 20:27:54 +0000385- Multiple inheritance mixing new-style and classic classes in the
386 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000387
388 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000389 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000390
391 The MRO (method resolution order) for each base class is respected
392 according to its kind, but the MRO for the derived class is computed
393 using new-style MRO rules if any base clase is a new-style class.
394 This needs to be documented.
395
Tim Petersa427a2b2001-10-29 22:25:45 +0000396- The new builtin dictionary() constructor, and dictionary type, have
397 been renamed to dict. This reflects a decade of common usage.
398
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000399- dict() now accepts an iterable object producing 2-sequences. For
400 example, dict(d.items()) == d for any dictionary d. The argument,
401 and the elements of the argument, can be any iterable objects.
402
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000403- New-style classes can now have a __del__ method, which is called
404 when the instance is deleted (just like for classic classes).
405
Guido van Rossum12d955c2001-10-26 14:56:06 +0000406- Assignment to object.__dict__ is now possible, for objects that are
407 instances of new-style classes that have a __dict__ (unless the base
408 class forbids it).
409
Guido van Rossumc8e56452001-10-22 00:43:43 +0000410- Methods of built-in types now properly check for keyword arguments
411 (formerly these were silently ignored). The only built-in methods
412 that take keyword arguments are __call__, __init__ and __new__.
413
Guido van Rossum86443212001-10-27 22:28:54 +0000414- The socket function has been converted to a type; see below.
415
Tim Peters84362bc2001-10-19 17:55:30 +0000416Core and builtins
417
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000418- Assignment to __debug__ raises SyntaxError at compile-time. This
419 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000420 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000421
Guido van Rossum12d955c2001-10-26 14:56:06 +0000422- Clarified the error messages for unsupported operands to an operator
423 (like 1 + '').
424
Tim Peters84362bc2001-10-19 17:55:30 +0000425Extension modules
426
Tim Peters5ebfd362001-11-13 23:11:19 +0000427- mmap has a new keyword argument, "access", allowing a uniform way for
428 both Windows and Unix users to create read-only, write-through and
429 copy-on-write memory mappings. This was previously possible only on
430 Unix. A new keyword argument was required to support this in a
431 uniform way because the mmap() signuatures had diverged across
432 platforms. Thanks to Jay T Miller for repairing this!
433
Tim Peters169ded02001-11-03 19:57:21 +0000434- By default, the gc.garbage list now contains only those instances in
435 unreachable cycles that have __del__ methods; in 2.1 it contained all
436 instances in unreachable cycles. "Instances" here has been generalized
437 to include instances of both new-style and old-style classes.
438
Guido van Rossum12d955c2001-10-26 14:56:06 +0000439- The socket module defines a new method for socket objects,
440 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000441 send() until all data has been sent. Also, the socket function has
442 been converted to a subclassable type, like list and tuple (etc.)
443 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000444
445- Various bugfixes to the curses module. There is now a test suite
446 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000447
Guido van Rossum692adf12001-10-30 03:03:03 +0000448- binascii.b2a_base64 no longer places an arbitrary restriction of 57
449 bytes on its input.
450
Tim Peters84362bc2001-10-19 17:55:30 +0000451Library
452
Tim Peters5ebfd362001-11-13 23:11:19 +0000453- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000454 convenience function.
455
Tim Peters75335872001-11-03 19:35:43 +0000456- Symbolic group names in regular expressions must be unique. For
457 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
458 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000459 Python 2.2 detects this error at regexp compilation time;
460 previously, the error went undetected, and results were
461 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
462 pattern.subn() methods have been rewritten in C. Also, an
463 experimental function/method finditer() has been added, which works
464 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000465
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000466- Tix exposes more commands through the classes DirSelectBox,
467 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
468 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
469 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
470
Tim Peters98791af2001-10-23 01:59:54 +0000471- Traceback objects are now scanned by cyclic garbage collection, so
472 cycles created by casual use of sys.exc_info() no longer cause
473 permanent memory leaks (provided garbage collection is enabled).
474
Guido van Rossum49192142001-10-24 20:51:44 +0000475- os.extsep -- a new variable needed by the RISCOS support. It is the
476 separator used by extensions, and is '.' on all platforms except
477 RISCOS, where it is '/'. There is no need to use this variable
478 unless you have a masochistic desire to port your code to RISCOS.
479
Barry Warsaw012852b2001-11-16 16:17:27 +0000480- mimetypes.py has optional support for non-standard, but commonly
481 found types. guess_type() and guess_extension() now accept an
482 optional `strict' flag, defaulting to true, which controls whether
483 recognize non-standard types or not. A few non-standard types we
484 know about have been added. Also, when run as a script, there are
485 new -l and -e options.
486
487- statcache is now deprecated.
488
489- email.Utils.formatdate() now produces the preferred RFC 2822 style
490 dates with numeric timezones (it used to produce obsolete dates
491 hard coded to "GMT" timezone). An optional `localtime' flag is
492 added to produce dates in the local timezone, with daylight savings
493 time properly taken into account.
494
495- In pickle and cPickle, instead of masking errors in load() by
496 transforming them into SystemError, we let the original exception
497 propagate out. Also, implement support for __safe_for_unpickling__
498 in pickle, as it already was supported in cPickle.
499
Tim Peters84362bc2001-10-19 17:55:30 +0000500Tools/Demos
501
502Build
503
Barry Warsaw012852b2001-11-16 16:17:27 +0000504- The dbm module is built using libdb1 if available. The bsddb module
505 is built with libdb3 if available.
506
507- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
508
Tim Peters84362bc2001-10-19 17:55:30 +0000509C API
510
Tim Peters1fc240e2001-10-26 05:06:50 +0000511- New function PySequence_Fast_GET_SIZE() returns the size of a non-
512 NULL result from PySequence_Fast(), more quickly than calling
513 PySequence_Size().
514
Barry Warsaw012852b2001-11-16 16:17:27 +0000515- New argument unpacking function PyArg_UnpackTuple() added.
516
517- New functions PyObject_CallFunctionObjArgs() and
518 PyObject_CallMethodObjArgs() have been added to make it more
519 convenient and efficient to call functions and methods from C.
520
521- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
522 possible that this will propagate errors it didn't before.
523
524- New function PyObject_CheckReadBuffer(), which returns true if its
525 argument supports the single-segment readable buffer interface.
526
Tim Peters84362bc2001-10-19 17:55:30 +0000527New platforms
528
Guido van Rossum86443212001-10-27 22:28:54 +0000529- We've finally confirmed that this release builds on HP-UX 11.00,
530 *with* threads, and passes the test suite.
531
Tim Peters7a33d8b2001-11-05 02:51:07 +0000532- Thanks to a series of patches from Michael Muller, Python may build
533 again under OS/2 Visual Age C++.
534
Guido van Rossum49192142001-10-24 20:51:44 +0000535- Updated RISCOS port by Dietmar Schwertberger.
536
Tim Peters84362bc2001-10-19 17:55:30 +0000537Tests
538
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000539- Added a test script for the curses module. It isn't run automatically;
540 regrtest.py must be run with '-u curses' to enable it.
541
Tim Peters84362bc2001-10-19 17:55:30 +0000542Windows
543
Barry Warsaw012852b2001-11-16 16:17:27 +0000544Mac
545
546- PythonScript has been moved to unsupported and is slated to be
547 removed completely in the next release.
548
549- It should now be possible to build applets that work on both OS9 and
550 OSX.
551
552- The core is now linked with CoreServices not Carbon; as a side
553 result, default 8bit encoding on OSX is now ASCII.
554
555- Python should now build on OSX 10.1.1
556
Tim Peters84362bc2001-10-19 17:55:30 +0000557
Tim Petersabf925f2001-09-28 21:53:42 +0000558What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000559Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000560===========================
561
562Type/class unification and new-style classes
563
Guido van Rossum687ae002001-10-15 22:03:32 +0000564- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000565 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000566 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000567 remains: the __dict__ of a new-style class is a read-only proxy; you
568 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000569 __defined__ attribute of new-style types no longer exists, for lack
570 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000571 future a __cache__ may be resurrected with a similar function, if I
572 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000573
Tim Peters1c9ca872001-10-04 06:43:12 +0000574- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
575 always returned None, even when there was a class docstring).
576
577- doctest now finds and runs docstrings attached to new-style classes,
578 class methods, static methods, and properties.
579
Guido van Rossum9074ef62001-10-16 21:34:49 +0000580Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000581
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000582- A very subtle syntactical pitfall in list comprehensions was fixed.
583 For example: [a+b for a in 'abc', for b in 'def']. The comma in
584 this example is a mistake. Previously, this would silently let 'a'
585 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
586 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
587 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
588 Note that [a for a in <singleton>] is a convoluted way to say
589 [<singleton>] anyway, so it's not like any expressiveness is lost.
590
Guido van Rossum9074ef62001-10-16 21:34:49 +0000591- getattr(obj, name, default) now only catches AttributeError, as
592 documented, rather than returning the default value for all
593 exceptions (which could mask bugs in a __getattr__ hook, for
594 example).
595
Fred Drakecb7a6b52001-10-22 18:41:51 +0000596- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000597 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000598 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000599 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000600
Guido van Rossum1c486092001-10-19 02:05:35 +0000601- unicode(obj) now behaves more like str(obj), accepting arbitrary
602 objects, and calling a __unicode__ method if it exists.
603 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000604 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000605
Barry Warsawf6fb1712001-10-19 05:35:40 +0000606- isinstance() now allows any object as the first argument and a
607 class, a type or something with a __bases__ tuple attribute for the
608 second argument. The second argument may also be a tuple of a
609 class, type, or something with __bases__, in which case isinstance()
610 will return true if the first argument is an instance of any of the
611 things contained in the second argument tuple. E.g.
612
613 isinstance(x, (A, B))
614
615 returns true if x is an instance of A or B.
616
Guido van Rossum9074ef62001-10-16 21:34:49 +0000617Extension modules
618
619- thread.start_new_thread() now returns the thread ID (previously None).
620
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000621- binascii has now two quopri support functions, a2b_qp and b2a_qp.
622
Guido van Rossumc524d952001-10-19 01:31:59 +0000623- readline now supports setting the startup_hook and the
624 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000625
Guido van Rossumc524d952001-10-19 01:31:59 +0000626- os and posix supports chroot(), setgroups() and unsetenv() where
627 available. The stat(), fstat(), statvfs() and fstatvfs() functions
628 now return "pseudo-sequences" -- the various fields can now be
629 accessed as attributes (e.g. os.stat("/").st_mtime) but for
630 backwards compatibility they also behave as a fixed-length sequence.
631 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000632 attributes.
633
634- time: localtime(), gmtime() and strptime() now return a
635 pseudo-sequence similar to the os.stat() return value, with
636 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000637
Guido van Rossum9074ef62001-10-16 21:34:49 +0000638- Decompression objects in the zlib module now accept an optional
639 second parameter to decompress() that specifies the maximum amount
640 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000641
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000642- optional SSL support in the socket module now exports OpenSSL
643 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
644 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000645 automatically seed its PRNG. Also, the keyfile and certfile
646 arguments to socket.ssl() are now optional.
647
648- posixmodule (and by extension, the os module on POSIX platforms) now
649 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000650
Guido van Rossum9074ef62001-10-16 21:34:49 +0000651Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000652
Tim Peters7402f792001-10-02 03:53:41 +0000653- doctest now excludes functions and classes not defined by the module
654 being tested, thanks to Tim Hochberg.
655
Fred Drakecb7a6b52001-10-22 18:41:51 +0000656- HotShot, a new profiler implemented using a C-based callback, has
657 been added. This substantially reduces the overhead of profiling,
658 but it is still quite preliminary. Support modules and
659 documentation will be added in upcoming releases (before 2.2 final).
660
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000661- profile now produces correct output in situations where an exception
662 raised in Python is cleared by C code (e.g. hasattr()). This used
663 to cause wrong output, including spurious claims of recursive
664 functions and attribution of time spent to the wrong function.
665
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000666 The code and documentation for the derived OldProfile and HotProfile
667 profiling classes was removed. The code hasn't worked for years (if
668 you tried to use them, they raised exceptions). OldProfile
669 intended to reproduce the behavior of the profiler Python used more
670 than 7 years ago, and isn't interesting anymore. HotProfile intended
671 to provide a faster profiler (but producing less information), and
672 that's a worthy goal we intend to meet via a different approach (but
673 without losing information).
674
Tim Peterscce092d2001-10-09 05:31:56 +0000675- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000676 a much better system-specific calibration constant. The constant can
677 now be specified in an instance constructor, or as a Profile class or
678 instance variable, instead of by editing profile.py's source code.
679 Calibration must still be done manually (see the docs for the profile
680 module).
681
682 Note that Profile.calibrate() must be overriden by subclasses.
683 Improving the accuracy required exploiting detailed knowledge of
684 profiler internals; the earlier method abstracted away the details
685 and measured a simplified model instead, but consequently computed
686 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000687
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000688- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000689 which indicates whether output is intended for the header 'Q'
690 encoding.
691
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000692- The SocketServer.ThreadingMixIn class now closes the request after
693 finish_request() returns. (Not when it errors out though.)
694
Barry Warsawf6fb1712001-10-19 05:35:40 +0000695- The nntplib module's NNTP.body() method has grown a `file' argument
696 to allow saving the message body to a file.
697
698- The email package has added a class email.Parser.HeaderParser which
699 only parses headers and does not recurse into the message's body.
700 Also, the module/class MIMEAudio has been added for representing
701 audio data (contributed by Anthony Baxter).
702
703- ftplib should be able to handle files > 2GB.
704
705- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
706 ON, and OFF.
707
Fred Drakecb7a6b52001-10-22 18:41:51 +0000708- xml.dom.minidom NodeList objects now support the length attribute
709 and item() method as required by the DOM specifications.
710
Guido van Rossumed554f62001-10-02 23:15:37 +0000711Tools/Demos
712
713- Demo/dns was removed. It no longer serves any purpose; a package
714 derived from it is now maintained by Anthony Baxter, see
715 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000716
Barry Warsawf6fb1712001-10-19 05:35:40 +0000717- The freeze tool has been made more robust, and two new options have
718 been added: -X and -E.
719
Tim Petersabf925f2001-09-28 21:53:42 +0000720Build
721
Barry Warsawf6fb1712001-10-19 05:35:40 +0000722- configure will use CXX in LINKCC if CXX is used to build main() and
723 the system requires to link a C++ main using the C++ compiler.
724
Tim Petersabf925f2001-09-28 21:53:42 +0000725C API
726
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000727- The documentation for the tp_compare slot is updated to require that
728 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
729 not correct. This is not yet enforced but will be enforced in
730 Python 2.3; even later, we may use -2 to indicate errors and +2 for
731 "NotImplemented". Right now, -1 should be used for an error return.
732
Tim Petersd38b1c72001-09-30 05:09:37 +0000733- PyLong_AsLongLong() now accepts int (as well as long) arguments.
734 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
735 as long) arguments.
736
Guido van Rossum3c288632001-10-16 21:13:49 +0000737- PyThread_start_new_thread() now returns a long int giving the thread
738 ID, if one can be calculated; it returns -1 for error, 0 if no
739 thread ID is calculated (this is an incompatible change, but only
740 the thread module used this API). This code has only really been
741 tested on Linux and Windows; other platforms please beware (and
742 report any bugs or strange behavior).
743
Guido van Rossum1c486092001-10-19 02:05:35 +0000744- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
745 input.
746
Tim Petersabf925f2001-09-28 21:53:42 +0000747New platforms
748
749Tests
750
751Windows
752
Tim Peters04cf1d32001-10-09 22:39:40 +0000753- Installer: If you install IDLE, and don't disable file-extension
754 registration, a new "Edit with IDLE" context (right-click) menu entry
755 is created for .py and .pyw files.
756
Tim Peters1ce3cf72001-10-01 17:58:40 +0000757- The signal module now supports SIGBREAK on Windows, thanks to Steven
758 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
759 action remains to call Win32 ExitProcess(). This can be changed via
760 signal.signal(). For example:
761
762 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
763 # (SIGINT) behavior.
764 import signal
765 signal.signal(signal.SIGBREAK,
766 signal.default_int_handler)
767
768 try:
769 while 1:
770 pass
771 except KeyboardInterrupt:
772 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
773 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
774 # program without the possibility for any Python-level cleanup).
775 print "Clean exit"
776
Tim Petersabf925f2001-09-28 21:53:42 +0000777
Tim Petersb07352e2001-09-08 01:25:47 +0000778What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000779Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000780===========================
781
Guido van Rossum808eea72001-09-25 04:15:41 +0000782Type/class unification and new-style classes
783
784- pydoc and inspect are now aware of new-style classes;
785 e.g. help(list) at the interactive prompt now shows proper
786 documentation for all operations on list objects.
787
788- Applications using Jim Fulton's ExtensionClass module can now safely
789 be used with Python 2.2. In particular, Zope 2.4.1 now works with
790 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
791 examples also work again. It is hoped that Gtk and Boost also work
792 with 2.2a4 and beyond. (If you can confirm this, please write
793 webmaster@python.org; if there are still problems, please open a bug
794 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000795
Tim Peters66c1a522001-09-24 21:17:50 +0000796- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
797 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
798 in the constructed property object. fget, fset and fdel weren't
799 discoverable from Python in 2.2a3. __doc__ is new, and allows to
800 associate a docstring with a property.
801
Guido van Rossum808eea72001-09-25 04:15:41 +0000802- Comparison overloading is now more completely implemented. For
803 example, a str subclass instance can properly be compared to a str
804 instance, and it can properly overload comparison. Ditto for most
805 other built-in object types.
806
807- The repr() of new-style classes has changed; instead of <type
808 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
809 *except* for built-in types, which are still rendered as <type
810 'Foo'> (to avoid upsetting existing code that might parse or
811 otherwise rely on repr() of certain type objects).
812
813- The repr() of new-style objects is now always <Foo object at XXX>;
814 previously, it was sometimes <Foo instance at XXX>.
815
816- For new-style classes, what was previously called __getattr__ is now
817 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000818 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000819 one in classic classes is defined which is called only if regular
820 attribute access raises AttributeError; to catch *all* attribute
821 access, you can use __getattribute__ (for new-style classes). If
822 both are defined, __getattribute__ is called first, and if it raises
823 AttributeError, __getattr__ is called.
824
825- The __class__ attribute of new-style objects can be assigned to.
826 The new class must have the same C-level object layout as the old
827 class.
828
829- The builtin file type can be subclassed now. In the usual pattern,
830 "file" is the name of the builtin type, and file() is a new builtin
831 constructor, with the same signature as the builtin open() function.
832 file() is now the preferred way to open a file.
833
834- Previously, __new__ would only see sequential arguments passed to
835 the type in a constructor call; __init__ would see both sequential
836 and keyword arguments. This made no sense whatsoever any more, so
837 now both __new__ and __init__ see all arguments.
838
839- Previously, hash() applied to an instance of a subclass of str or
840 unicode always returned 0. This has been repaired.
841
842- Previously, an operation on an instance of a subclass of an
843 immutable type (int, long, float, complex, tuple, str, unicode),
844 where the subtype didn't override the operation (and so the
845 operation was handled by the builtin type), could return that
846 instance instead a value of the base type. For example, if s was of
847 a str sublass type, s[:] returned s as-is. Now it returns a str
848 with the same value as s.
849
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000850- Provisional support for pickling new-style objects has been added.
851
Guido van Rossum808eea72001-09-25 04:15:41 +0000852Core
853
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000854- file.writelines() now accepts any iterable object producing strings.
855
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000856- PyUnicode_FromEncodedObject() now works very much like
857 PyObject_Str(obj) in that it tries to use __str__/tp_str
858 on the object if the object is not a string or buffer. This
859 makes unicode() behave like str() when applied to non-string/buffer
860 objects.
861
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000862- PyFile_WriteObject now passes Unicode objects to the file's write
863 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000864 of a print statement must support Unicode objects, i.e. they must
865 at least convert them into ASCII strings.
866
Guido van Rossum624c8af2001-09-18 15:21:04 +0000867- Thread scheduling on Solaris should be improved; it is no longer
868 necessary to insert a small sleep at the start of a thread in order
869 to let other runnable threads be scheduled.
870
Tim Petersb07352e2001-09-08 01:25:47 +0000871Library
872
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000873- StringIO.StringIO instances and cStringIO.StringIO instances support
874 read character buffer compatible objects for their .write() methods.
875 These objects are converted to strings and then handled as such
876 by the instances.
877
Barry Warsaw2f600732001-09-24 04:28:10 +0000878- The "email" package has been added. This is basically a port of the
879 mimelib package <http://sf.net/projects/mimelib> with API changes
880 and some implementations updated to use iterators and generators.
881
Tim Peters8a9c2842001-09-22 21:30:22 +0000882- difflib.ndiff() and difflib.Differ.compare() are generators now. This
883 restores the ability of Tools/scripts/ndiff.py to start producing output
884 before the entire comparison is complete.
885
Barry Warsaw58b072d2001-09-22 04:44:21 +0000886- StringIO.StringIO instances and cStringIO.StringIO instances support
887 iteration just like file objects (i.e. their .readline() method is
888 called for each iteration until it returns an empty string).
889
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000890- The codecs module has grown four new helper APIs to access
891 builtin codecs: getencoder(), getdecoder(), getreader(),
892 getwriter().
893
Guido van Rossum624c8af2001-09-18 15:21:04 +0000894- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
895 simplifies writing XML RPC servers.
896
Barry Warsaw647d5e82001-09-28 17:01:02 +0000897- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000898 after interpretation of symbolic links. On non-Unix systems, this
899 is an alias for os.path.abspath().
900
Tim Peters16a77ad2001-09-08 04:00:12 +0000901- operator.indexOf() (PySequence_Index() in the C API) now works with any
902 iterable object.
903
Guido van Rossum624c8af2001-09-18 15:21:04 +0000904- smtplib now supports various authentication and security features of
905 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000906
Guido van Rossum624c8af2001-09-18 15:21:04 +0000907- hmac: a new module implementing keyed hashing for message
908 authentication.
909
910- mimetypes now recognizes more extensions and file types. At the
911 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000912
Guido van Rossum624c8af2001-09-18 15:21:04 +0000913- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000914 Python 2.2 bytecode generation. It has also been promoted from a
915 Tool to a standard library package. (Tools/compiler still exists as
916 a sample driver.)
917
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000918Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000919
Tim Petersb07352e2001-09-08 01:25:47 +0000920Build
921
Guido van Rossum624c8af2001-09-18 15:21:04 +0000922- Large file support (LFS) is now automatic when the platform supports
923 it; no more manual configuration tweaks are needed. On Linux, at
924 least, it's possible to have a system whose C library supports large
925 files but whose kernel doesn't; in this case, large file support is
926 still enabled but doesn't do you any good unless you upgrade your
927 kernel or share your Python executable with another system whose
928 kernel has large file support.
929
930- The configure script now supplies plausible defaults in a
931 cross-compilation environment. This doesn't mean that the supplied
932 values are always correct, or that cross-compilation now works
933 flawlessly -- but it's a first step (and it shuts up most of
934 autoconf's warnings about AC_TRY_RUN).
935
936- The Unix build is now a bit less chatty, courtesy of the parser
937 generator. The build is completely silent (except for errors) when
938 using "make -s", thanks to a -q option to setup.py.
939
Tim Petersb07352e2001-09-08 01:25:47 +0000940C API
941
Guido van Rossum624c8af2001-09-18 15:21:04 +0000942- The "structmember" API now supports some new flag bits to deny read
943 and/or write access to attributes in restricted execution mode.
944
Tim Petersb07352e2001-09-08 01:25:47 +0000945New platforms
946
Guido van Rossum624c8af2001-09-18 15:21:04 +0000947- Compaq's iPAQ handheld, running the "familiar" Linux distribution
948 (http://familiar.handhelds.org).
949
Tim Petersb07352e2001-09-08 01:25:47 +0000950Tests
951
Tim Peters8a9c2842001-09-22 21:30:22 +0000952- The "classic" standard tests, which work by comparing stdout to
953 an expected-output file under Lib/test/output/, no longer stop at
954 the first mismatch. Instead the test is run to completion, and a
955 variant of ndiff-style comparison is used to report all differences.
956 This is much easier to understand than the previous style of reporting.
957
958- The unittest-based standard tests now use regrtest's test_main()
959 convention, instead of running as a side-effect of merely being
960 imported. This allows these tests to be run in more natural and
961 flexible ways as unittests, outside the regrtest framework.
962
963- regrtest.py is much better integrated with unittest and doctest now,
964 especially in regard to reporting errors.
965
Tim Petersb07352e2001-09-08 01:25:47 +0000966Windows
967
Guido van Rossum624c8af2001-09-18 15:21:04 +0000968- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000969 that support it (NTFS under Windows 2000). See "What's New in
970 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000971
Tim Petersb07352e2001-09-08 01:25:47 +0000972
Tim Petersedc99312001-08-22 21:36:50 +0000973What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000974Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000975===========================
976
977Core
978
Tim Peters9fffa3e2001-09-04 05:14:19 +0000979- Conversion of long to float now raises OverflowError if the long is too
980 big to represent as a C double.
981
Tim Peters32f453e2001-09-03 08:35:41 +0000982- The 3-argument builtin pow() no longer allows a third non-None argument
983 if either of the first two arguments is a float, or if both are of
984 integer types and the second argument is negative (in which latter case
985 the arguments are converted to float, so this is really the same
986 restriction).
987
Tim Peters5d2b77c2001-09-03 05:47:38 +0000988- The builtin dir() now returns more information, and sometimes much
989 more, generally naming all attributes of an object, and all attributes
990 reachable from the object via its class, and from its class's base
991 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
992 an empty list. In 2.2a3,
993
994 >>> dir([])
995 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
996 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
997 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
998 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
999 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
1000 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
1001 'reverse', 'sort']
1002
1003 dir(module) continues to return only the module's attributes, though.
1004
Tim Petersbdee63f2001-09-02 03:40:59 +00001005- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +00001006 than raising OverflowError. This is a partial implementation of PEP
1007 237. You can use -Wdefault::OverflowWarning to enable a warning for
1008 this situation, and -Werror::OverflowWarning to revert to the old
1009 OverflowError exception.
1010
Guido van Rossum61c345f2001-09-04 03:26:15 +00001011- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +00001012 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001013 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
1014 -Qold, meaning the / operator has its classic meaning and no
1015 warnings are issued. Using -Qwarn issues a run-time warning about
1016 all uses of classic division for int and long arguments; -Qwarnall
1017 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +00001018 (for use with fixdiv.py).
1019 [Note: the remainder of this paragraph (preserved below) became
1020 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
1021 <obsolete>
1022 Using -Qnew is questionable; it turns on new division by default, but
1023 only in the __main__ module. You can usefully combine -Qwarn or
1024 -Qwarnall and -Qnew: this gives the __main__ module new division, and
1025 warns about classic division everywhere else.
1026 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +00001027
Tim Petersbdee63f2001-09-02 03:40:59 +00001028- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +00001029 long, float, str, unicode, and tuple. (The types complex, list and
1030 dictionary can also be subclassed; this was introduced earlier.)
1031 Note that restrictions apply when subclassing immutable built-in
1032 types: you can only affect the value of the instance by overloading
1033 __new__. You can add mutable attributes, and the subclass instances
1034 will have a __dict__ attribute, but you cannot change the "value"
1035 (as implemented by the base class) of an immutable subclass instance
1036 once it is created.
1037
Guido van Rossumaaf80c82001-09-02 13:44:35 +00001038- The dictionary constructor now takes an optional argument, a
1039 mapping-like object, and initializes the dictionary from its
1040 (key, value) pairs.
1041
Tim Petersbdee63f2001-09-02 03:40:59 +00001042- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +00001043 "cooperative super calls" in a multiple inheritance setting. For an
1044 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
1045
Guido van Rossum8d7234d2001-09-06 22:02:58 +00001046- A new built-in type, property, has been added. This enables the
1047 creation of "properties". These are attributes implemented by
1048 getter and setter functions (or only one of these for read-only or
1049 write-only attributes), without the need to override __getattr__.
1050 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +00001051
Tim Petersbdee63f2001-09-02 03:40:59 +00001052- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +00001053 liberalized, to allow leading zeroes. Examples of literals now
1054 legal that were SyntaxErrors before:
1055
1056 00.0 0e3 0100j 07.5 00000000000000000008.
1057
Tim Petersbdee63f2001-09-02 03:40:59 +00001058- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +00001059 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
1060
Tim Petersedc99312001-08-22 21:36:50 +00001061Library
1062
Martin v. Löwiscb227c92001-09-06 08:54:16 +00001063- telnetlib includes symbolic names for the options, and support for
1064 setting an option negotiation callback.
1065
Tim Petersa40c7932001-09-05 22:36:56 +00001066- The new C standard no longer requires that math libraries set errno to
1067 ERANGE on overflow. For platform libraries that exploit this new
1068 freedom, Python's overflow-checking was wholly broken. A new overflow-
1069 checking scheme attempts to repair that, but may not be reliable on all
1070 platforms (C doesn't seem to provide anything both useful and portable
1071 in this area anymore).
1072
Martin v. Löwis44f86962001-09-05 13:44:54 +00001073- Asynchronous timeout actions are available through the new class
1074 threading.Timer.
1075
Tim Peters78526162001-09-05 00:53:45 +00001076- math.log and math.log10 now return sensible results for even huge
1077 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1078
Tim Petersbdee63f2001-09-02 03:40:59 +00001079- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001080 currently held. See the docs for the imp module.
1081
Tim Petersbdee63f2001-09-02 03:40:59 +00001082- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001083 dumps containing ints written on platforms where Python ints are 8 bytes.
1084 When read on a box where Python ints are 4 bytes, such values are
1085 converted to Python longs.
1086
Tim Petersbdee63f2001-09-02 03:40:59 +00001087- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001088 code objects is no longer allowed. This plugs a security hole.
1089
Steve Purcell6091cd62001-09-06 16:05:17 +00001090- unittest.TestResult instances no longer store references to tracebacks
1091 generated by test failures. This prevents unexpected dangling references
1092 to objects that should be garbage collected between tests.
1093
Tim Petersedc99312001-08-22 21:36:50 +00001094Tools
1095
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001096- Tools/scripts/fixdiv.py has been added which can be used to fix
1097 division operators as per PEP 238.
1098
Tim Petersedc99312001-08-22 21:36:50 +00001099Build
1100
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001101- If you are an adventurous person using Mac OS X you may want to look at
1102 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1103 application, which can be used for experimenting with Carbon or Cocoa.
1104 Discussion of this on pythonmac-sig, please.
1105
Tim Peters7eea37e2001-09-04 22:08:56 +00001106C API
1107
1108- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001109
Tim Peters9fffa3e2001-09-04 05:14:19 +00001110- Note that PyLong_AsDouble can fail! This has always been true, but no
1111 callers checked for it. It's more likely to fail now, because overflow
1112 errors are properly detected now. The proper way to check:
1113
1114 double x = PyLong_AsDouble(some_long_object);
1115 if (x == -1.0 && PyErr_Occurred()) {
1116 /* The conversion failed. */
1117 }
1118
Tim Petersbdee63f2001-09-02 03:40:59 +00001119- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001120 compile but will not participate in GC. To upgrade an extension
1121 module:
1122
1123 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001124
Neil Schemenauer4042c692001-08-30 15:38:01 +00001125 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1126 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001127
Neil Schemenauer4042c692001-08-30 15:38:01 +00001128 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1129 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001130
Neil Schemenauer4042c692001-08-30 15:38:01 +00001131 - remove PyGC_HEAD_SIZE from object size calculations
1132
1133 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1134
Tim Petersbdee63f2001-09-02 03:40:59 +00001135- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001136 These can be used safely to construct string objects from a
1137 sprintf-style format string (similar to the format string supported
1138 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001139
Tim Petersedc99312001-08-22 21:36:50 +00001140New platforms
1141
Tim Petersb7da0902001-09-02 23:01:43 +00001142- Stephen Hansen contributed patches sufficient to get a clean compile
1143 under Borland C (Windows), but he reports problems running it and ran
1144 out of time to complete the port. Volunteers? Expect a MemoryError
1145 when importing the types module; this is probably shallow, and
1146 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001147
Tim Petersedc99312001-08-22 21:36:50 +00001148Tests
1149
1150Windows
1151
Tim Peters6e13a562001-09-06 00:32:15 +00001152- Large file support is now enabled on Win32 platforms as well as on
1153 Win64. This means that, for example, you can use f.tell() and f.seek()
1154 to manipulate files larger than 2 gigabytes (provided you have enough
1155 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001156 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1157 filesize limit, and large file support makes no difference there.
1158 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1159 NTFS has no practical limit on file size, and files of any size can be
1160 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001161
Tim Petersbdee63f2001-09-02 03:40:59 +00001162- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001163 points to command.com (patch from Brian Quinlan).
1164
Tim Petersedc99312001-08-22 21:36:50 +00001165
Tim Peters20f51a72001-07-21 02:31:40 +00001166What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001167Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001168===========================
1169
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001170Build
1171
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001172- Tim Peters developed a brand new Windows installer using Wise 8.1,
1173 generously donated to us by Wise Solutions.
1174
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001175- configure supports a new option --enable-unicode, with the values
1176 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1177 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001178
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001179- A new configure option --enable-framework builds a Mac OS X framework,
1180 which "make frameworkinstall" will install. This provides a starting
1181 point for more mac-like functionality, join pythonmac-sig@python.org
1182 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001183
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001184- The NeXT platform is no longer supported.
1185
1186- The `new' module is now statically linked.
1187
Tim Peters0afb6092001-08-15 06:06:44 +00001188Tools
1189
1190- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001191 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001192 the module docstring for details.
1193
Tim Peters20f51a72001-07-21 02:31:40 +00001194Tests
1195
Tim Peters5e824c32001-08-12 22:25:01 +00001196- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001197 platforms, allowing to give clearer test result output. regrtest
1198 also has optional --use/-u switch to run normally disabled tests
1199 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001200
Tim Peters20f51a72001-07-21 02:31:40 +00001201- Several new tests in the standard test suite, with special thanks to
1202 Nick Mathewson.
1203
1204Core
1205
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001206- The floor division operator // has been added as outlined in PEP
1207 238. The / operator still provides classic division (and will until
1208 Python 3.0) unless "from __future__ import division" is included, in
1209 which case the / operator will provide true division. The operator
1210 module provides truediv() and floordiv() functions. Augmented
1211 assignment variants are included, as are the equivalent overloadable
1212 methods and C API methods. See the PEP for a full discussion:
1213 <http://python.sf.net/peps/pep-0238.html>
1214
Tim Peters6cd6a822001-08-17 22:11:27 +00001215- Future statements are now effective in simulated interactive shells
1216 (like IDLE). This should "just work" by magic, but read Michael
1217 Hudson's "Future statements in simulated shells" PEP 264 for full
1218 details: <http://python.sf.net/peps/pep-0264.html>.
1219
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001220- The type/class unification (PEP 252-253) was integrated into the
1221 trunk and is not so tentative any more (the exact specification of
1222 some features is still tentative). A lot of work has done on fixing
1223 bugs and adding robustness and features (performance still has to
1224 come a long way).
1225
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001226- Warnings about a mismatch in the Python API during extension import
1227 now use the Python warning framework (which makes it possible to
1228 write filters for these warnings).
1229
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001230- A function's __dict__ (aka func_dict) will now always be a
1231 dictionary. It used to be possible to delete it or set it to None,
1232 but now both actions raise TypeErrors. It is still legal to set it
1233 to a dictionary object. Getting func.__dict__ before any attributes
1234 have been assigned now returns an empty dictionary instead of None.
1235
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001236- A new command line option, -E, was added which disables the use of
1237 all environment variables, or at least those that are specifically
1238 significant to Python. Usually those have a name starting with
1239 "PYTHON". This was used to fix a problem where the tests fail if
1240 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1241 older distribution.
1242
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001243Library
1244
Tim Peters5e824c32001-08-12 22:25:01 +00001245- New class Differ and new functions ndiff() and restore() in difflib.py.
1246 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001247 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001248
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001249- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1250 value using the minimal quoting required for the value; more
1251 reliable than using xml.sax.saxutils.escape() for attribute values.
1252
1253- Readline completion support for cmd.Cmd was added.
1254
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001255- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1256
1257- Added function threading.BoundedSemaphore()
1258
1259- Added Ka-Ping Yee's cgitb.py module.
1260
1261- The `new' module now exposes the CO_xxx flags.
1262
Martin v. Löwis560da622001-11-24 09:24:51 +00001263- The gc module offers the get_referents function.
1264
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001265New platforms
1266
1267C API
1268
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001269- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1270 which provide a cross-platform implementations for the
1271 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1272 the standard sprintf() and vsprintf() C lib APIs, these versions
1273 apply bounds checking on the used buffer which enhances protection
1274 against buffer overruns.
1275
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001276- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001277 and extensions using different Unicode widths is rendered next to
1278 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001279 will result in an ImportError. Unicode extensions writers must make
1280 sure to check the Unicode width compatibility in their extensions by
1281 using at least one of the mangled Unicode APIs in the extension.
1282
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001283- Two new flags METH_NOARGS and METH_O are available in method definition
1284 tables to simplify implementation of methods with no arguments and a
1285 single untyped argument. Calling such methods is more efficient than
1286 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1287 deprecated.
1288
Tim Petersc1731372001-08-04 08:12:36 +00001289Windows
1290
1291- "import module" now compiles module.pyw if it exists and nothing else
1292 relevant is found.
1293
Tim Peters20f51a72001-07-21 02:31:40 +00001294
Guido van Rossum55a78992001-07-17 17:22:32 +00001295What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001296Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001297===========================
1298
1299Core
Tim Petersa814db52001-05-14 07:05:58 +00001300
Tim Peters6d6c1a32001-08-02 04:15:00 +00001301- TENTATIVELY, a large amount of code implementing much of what's
1302 described in PEP 252 (Making Types Look More Like Classes) and PEP
1303 253 (Subtyping Built-in Types) was added. This will be released
1304 with Python 2.2a1. Documentation will be provided separately
1305 through http://www.python.org/2.2/. The purpose of releasing this
1306 with Python 2.2a1 is to test backwards compatibility. It is
1307 possible, though not likely, that a decision is made not to release
1308 this code as part of 2.2 final, if any serious backwards
1309 incompapatibilities are found during alpha testing that cannot be
1310 repaired.
1311
Guido van Rossum55a78992001-07-17 17:22:32 +00001312- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001313 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001314 more 'yield' statements. See PEP 255. Since this adds a new
1315 keyword to the language, this feature must be enabled by including a
1316 future statement: "from __future__ import generators" (see PEP 236).
1317 Generators will become a standard feature in a future release
1318 (probably 2.3). Without this future statement, 'yield' remains an
1319 ordinary identifier, but a warning is issued each time it is used.
1320 (These warnings currently don't conform to the warnings framework of
1321 PEP 230; we intend to fix this in 2.2a2.)
1322
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001323- The UTF-16 codec was modified to be more RFC compliant. It will now
1324 only remove BOM characters at the start of the string and then
1325 only if running in native mode (UTF-16-LE and -BE won't remove a
1326 leading BMO character).
1327
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001328- Strings now have a new method .decode() to complement the already
1329 existing .encode() method. These two methods provide direct access
1330 to the corresponding decoders and encoders of the registered codecs.
1331
1332 To enhance the usability of the .encode() method, the special
1333 casing of Unicode object return values was dropped (Unicode objects
1334 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001335
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001336 Both methods will now return whatever the codec in charge of the
1337 requested encoding returns as object, e.g. Unicode codecs will
1338 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1339 will return u"äöü"). This enables codec writer to create codecs
1340 for various simple to use conversions.
1341
1342 New codecs were added to demonstrate these new features (the .encode()
1343 and .decode() columns indicate the type of the returned objects):
1344
1345 Name | .encode() | .decode() | Description
1346 ----------------------------------------------------------------------
1347 uu | string | string | UU codec (e.g. for email)
1348 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001349 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001350 zlib | string | string | zlib compression
1351 hex | string | string | 2-byte hex codec
1352 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1353
Mark Hammond2a0af792001-05-14 03:09:36 +00001354- Some operating systems now support the concept of a default Unicode
1355 encoding for file system operations. Notably, Windows supports 'mbcs'
1356 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001357 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001358 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001359
1360 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001361 functions that return filenames (such as os.listdir()) to return Python
1362 string objects pre-encoded using the default file system encoding for
1363 the platform. As this encoding is likely to be different from Python's
1364 default encoding, converting this name to a Unicode object before passing
1365 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001366 would attempt to use its default encoding (generally ASCII) rather than
1367 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001368
Tim Petersa814db52001-05-14 07:05:58 +00001369 In general, this change simply removes surprises when working with
1370 Unicode and the file system, making these operations work as you expect,
1371 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001372 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001373
Tim Peters61dff2b2001-05-08 15:43:37 +00001374- Float (and complex) literals in source code were evaluated to full
1375 precision only when running from a .py file; the same code loaded from a
1376 .pyc (or .pyo) file could suffer numeric differences starting at about the
1377 12th significant decimal digit. For example, on a machine with IEEE-754
1378 floating arithmetic,
1379
1380 x = 9007199254740992.0
1381 print long(x)
1382
1383 printed 9007199254740992 if run directly from .py, but 9007199254740000
1384 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1385 str(float) instead of repr(float) when building code objects. marshal
1386 now uses repr(float) instead, which should reproduce floats to full
1387 machine precision (assuming the platform C float<->string I/O conversion
1388 functions are of good quality).
1389
1390 This may cause floating-point results to change in some cases, and
1391 usually for the better, but may also cause numerically unstable
1392 algorithms to break.
1393
Tim Peters2f228e72001-05-13 00:19:31 +00001394- The implementation of dicts suffers fewer collisions, which has speed
1395 benefits. However, the order in which dict entries appear in dict.keys(),
1396 dict.values() and dict.items() may differ from previous releases for a
1397 given dict. Nothing is defined about this order, so no program should
1398 rely on it. Nevertheless, it's easy to write test cases that rely on the
1399 order by accident, typically because of printing the str() or repr() of a
1400 dict to an "expected results" file. See Lib/test/test_support.py's new
1401 sortdict(dict) function for a simple way to display a dict in sorted
1402 order.
1403
Tim Peters7a3bfc32001-06-12 01:22:22 +00001404- Many other small changes to dicts were made, resulting in faster
1405 operation along the most common code paths.
1406
Guido van Rossum10315822001-05-01 20:54:30 +00001407- Dictionary objects now support the "in" operator: "x in dict" means
1408 the same as dict.has_key(x).
1409
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001410- The update() method of dictionaries now accepts generic mapping
1411 objects. Specifically the argument object must support the .keys()
1412 and __getitem__() methods. This allows you to say, for example,
1413 {}.update(UserDict())
1414
Guido van Rossum10315822001-05-01 20:54:30 +00001415- Iterators were added; this is a generalized way of providing values
1416 to a for loop. See PEP 234. There's a new built-in function iter()
1417 to return an iterator. There's a new protocol to get the next value
1418 from an iterator using the next() method (in Python) or the
1419 tp_iternext slot (in C). There's a new protocol to get iterators
1420 using the __iter__() method (in Python) or the tp_iter slot (in C).
1421 Iterating (i.e. a for loop) over a dictionary generates its keys.
1422 Iterating over a file generates its lines.
1423
Tim Petersf553f892001-05-01 20:45:31 +00001424- The following functions were generalized to work nicely with iterator
1425 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001426 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001427 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1428 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001429 join() method of strings
1430 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001431 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1432 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001433 right-hand side of assignment statements with multiple targets, such as
1434 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001435
Tim Petersd85e1022001-05-11 21:51:48 +00001436- Accessing module attributes is significantly faster (for example,
1437 random.random or os.path or yourPythonModule.yourAttribute).
1438
Tim Peterse63415e2001-05-08 04:38:29 +00001439- Comparing dictionary objects via == and != is faster, and now works even
1440 if the keys and values don't support comparisons other than ==.
1441
Tim Peters95bf9392001-05-10 08:32:44 +00001442- Comparing dictionaries in ways other than == and != is slower: there were
1443 insecurities in the dict comparison implementation that could cause Python
1444 to crash if the element comparison routines for the dict keys and/or
1445 values mutated the dicts. Making the code bulletproof slowed it down.
1446
Tim Peterseb28ef22001-06-02 05:27:19 +00001447- Collisions in dicts are resolved via a new approach, which can help
1448 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001449 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001450 faster now. Thanks to Christian Tismer for pointing out the cause and
1451 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001452
Tim Peters52e155e2001-06-16 05:42:57 +00001453- repr() is much faster for large containers (dict, list, tuple).
1454
1455
Tim Petersa814db52001-05-14 07:05:58 +00001456Library
1457
Fred Drake960fdf92001-07-20 18:38:26 +00001458- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1459 were added to the string module. These a locale-indenpendent
1460 constants, unlike letters, lowercase, and uppercase. These are now
1461 use in appropriate locations in the standard library.
1462
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001463- The flags used in dlopen calls can now be configured using
1464 sys.setdlopenflags and queried using sys.getdlopenflags.
1465
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001466- Fredrik Lundh's xmlrpclib is now a standard library module. This
1467 provides full client-side XML-RPC support. In addition,
1468 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1469 one asyncore-based). Thanks to Eric Raymond for the documentation.
1470
Guido van Rossum643d3912001-07-05 14:46:25 +00001471- The xrange() object is simplified: it no longer supports slicing,
1472 repetition, comparisons, efficient 'in' checking, the tolist()
1473 method, or the start, stop and step attributes. See PEP 260.
1474
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001475- A new function fnmatch.filter to filter lists of file names was added.
1476
Barry Warsawffd674d2001-05-22 16:00:10 +00001477- calendar.py uses month and day names based on the current locale.
1478
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001479- strop is now *really* obsolete (this was announced before with 1.6),
1480 and issues DeprecationWarning when used (except for the four items
1481 that are still imported into string.py).
1482
Tim Petersa814db52001-05-14 07:05:58 +00001483- Cookie.py now sorts key+value pairs by key in output strings.
1484
1485- pprint.isrecursive(object) didn't correctly identify recursive objects.
1486 Now it does.
1487
Tim Peters95b3f782001-05-14 18:39:41 +00001488- pprint functions now much faster for large containers (tuple, list, dict).
1489
Tim Peters7b9542a2001-06-10 23:40:19 +00001490- New 'q' and 'Q' format codes in the struct module, corresponding to C
1491 types "long long" and "unsigned long long" (on Windows, __int64). In
1492 native mode, these can be used only when the platform C compiler supports
1493 these types (when HAVE_LONG_LONG is #define'd by the Python config
1494 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001495 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1496 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001497
Guido van Rossum83213cc2001-06-12 16:48:52 +00001498- The site module installs a new built-in function 'help' that invokes
1499 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1500 it displays a message reminding the user to use 'help()' or
1501 'help(object)'.
1502
Tim Petersa814db52001-05-14 07:05:58 +00001503Tests
1504
1505- New test_mutants.py runs dict comparisons where the key and value
1506 comparison operators mutute the dicts randomly during comparison. This
1507 rapidly causes Python to crash under earlier releases (not for the faint
1508 of heart: it can also cause Win9x to freeze or reboot!).
1509
1510- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001511 pprint.isreadable() return sensible results. Also verifies that simple
1512 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001513
Tim Peters4324aa32001-05-28 22:30:08 +00001514C API
1515
1516- Removed the unused last_is_sticky argument from the internal
1517 _PyTuple_Resize(). If this affects you, you were cheating.
1518
1519
Guido van Rossum55a78992001-07-17 17:22:32 +00001520======================================================================
1521
1522
Guido van Rossumffe13be2001-04-16 18:46:45 +00001523What's New in Python 2.1 (final)?
1524=================================
1525
1526We only changed a few things since the last release candidate, all in
1527Python library code:
1528
1529- A bug in the locale module was fixed that affected locales which
1530 define no grouping for numeric formatting.
1531
1532- A few bugs in the weakref module's implementations of weak
1533 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1534 and the test suite was updated to check for these bugs.
1535
1536- An old bug in the os.path.walk() function (introduced in Python
1537 2.0!) was fixed: a non-existent file would cause an exception
1538 instead of being ignored.
1539
1540- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1541 PyChecker.
1542
1543
Guido van Rossum5b08f132001-04-16 02:05:23 +00001544What's New in Python 2.1c2?
1545===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001546
Guido van Rossum5b08f132001-04-16 02:05:23 +00001547A flurry of small changes, and one showstopper fixed in the nick of
1548time made it necessary to release another release candidate. The list
1549here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001550
Guido van Rossum5b08f132001-04-16 02:05:23 +00001551Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001552
Guido van Rossum5b08f132001-04-16 02:05:23 +00001553- Tim discovered a nasty bug in the dictionary code, caused by
1554 PyDict_Next() calling dict_resize(), and the GC code's use of
1555 PyDict_Next() violating an assumption in dict_items(). This was
1556 fixed with considerable amounts of band-aid, but the net effect is a
1557 saner and more robust implementation.
1558
1559- Made a bunch of symbols static that were accidentally global.
1560
1561Build and Ports
1562
1563- The setup.py script didn't check for a new enough version of zlib
1564 (1.1.3 is needed). Now it does.
1565
1566- Changed "make clean" target to also remove shared libraries.
1567
1568- Added a more general warning about the SGI Irix optimizer to README.
1569
1570Library
1571
1572- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1573 omitted the slash between host and file.html.
1574
1575- The mailbox module's _Mailbox class contained a completely broken
1576 and undocumented seek() method. Ripped it out.
1577
1578- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1579 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1580
1581- Fixed a few last-minute bugs in unittest.
1582
1583Extensions
1584
1585- Reverted the patch to the OpenSSL code in socketmodule.c to support
1586 RAND_status() and the EGD, and the subsequent patch that tried to
1587 fix it for pre-0.9.5 versions; the problem with the patch is that on
1588 some systems it issues a warning whenever socket is imported, and
1589 that's unacceptable.
1590
1591Tests
1592
1593- Fixed the pickle tests to work with "import test.test_pickle".
1594
1595- Tweaked test_locale.py to actually run the test Windows.
1596
1597- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1598 not "wb" (which is not a valid mode at all).
1599
1600- Fix pstats browser crashes. Import readline if it exists to make
1601 the user interface nicer.
1602
1603- Add "import thread" to the top of test modules that import the
1604 threading module (test_asynchat and test_threadedtempfile). This
1605 prevents test failures caused by a broken threading module resulting
1606 from a previously caught failed import.
1607
1608- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1609 needed on some platforms (e.g. Solaris 8) when the tests are run
1610 twice in succession.
1611
1612- Skip rather than fail test_sunaudiodev if no audio device is found.
1613
1614
1615What's New in Python 2.1c1?
1616===========================
1617
1618This list was significantly updated when 2.1c2 was released; the 2.1c1
1619release didn't mention most changes that were actually part of 2.1c1:
1620
1621Legal
1622
1623- Copyright was assigned to the Python Software Foundation (PSF) and a
1624 PSF license (very similar to the CNRI license) was added.
1625
1626- The CNRI copyright notice was updated to include 2001.
1627
1628Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001629
Guido van Rossumc9932722001-04-12 02:31:27 +00001630- After a public outcry, assignment to __debug__ is no longer illegal;
1631 instead, a warning is issued. It will become illegal in 2.2.
1632
Guido van Rossum5b08f132001-04-16 02:05:23 +00001633- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1634 "%#x" now always prepends "0x", even if the value is zero.
1635
1636- Fixed some nits in the bytecode compiler.
1637
1638- Fixed core dumps when calling certain kinds of non-functions.
1639
1640- Fixed various core dumps caused by reference count bugs.
1641
1642Build and Ports
1643
1644- Use INSTALL_SCRIPT to install script files.
1645
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001646- New port: SCO Unixware 7, by Billy G. Allie.
1647
Guido van Rossum5b08f132001-04-16 02:05:23 +00001648- Updated RISCOS port.
1649
1650- Updated BeOS port and notes.
1651
1652- Various other porting problems resolved.
1653
1654Library
1655
1656- The TERMIOS and SOCKET modules are now truly obsolete and
1657 unnecessary. Their symbols are incorporated in the termios and
1658 socket modules.
1659
1660- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1661 better tests for pickling.
1662
1663- threading: make Condition.wait() robust against KeyboardInterrupt.
1664
1665- zipfile: add support to zipfile to support opening an archive
1666 represented by an open file rather than a file name. Fix bug where
1667 the archive was not properly closed. Fixed a bug in this bugfix
1668 where flush() was called for a read-only file.
1669
1670- imputil: added an uninstall() method to the ImportManager.
1671
1672- Canvas: fixed bugs in lower() and tkraise() methods.
1673
1674- SocketServer: API change (added overridable close_request() method)
1675 so that the TCP server can explicitly close the request.
1676
1677- pstats: Eric Raymond added a simple interactive statistics browser,
1678 invoked when the module is run as a script.
1679
1680- locale: fixed a problem in format().
1681
1682- webbrowser: made it work when the BROWSER environment variable has a
1683 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1684 KDE 2. Fixed some other nits.
1685
1686- unittest: changes to allow using a different exception than
1687 AssertionError, and added a few more function aliases. Some other
1688 small changes.
1689
1690- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1691
1692- asynchat: fixed a critical bug in asynchat that slipped through the
1693 2.1b2 release. Fixed another rare bug.
1694
1695- Fix some unqualified except: clauses (always a bad code example).
1696
1697XML
1698
1699- pyexpat: new API get_version_string().
1700
1701- Fixed some minidom bugs.
1702
1703Extensions
1704
1705- Fixed a core dump in _weakref. Removed the weakref.mapping()
1706 function (it adds nothing to the API).
1707
1708- Rationalized the use of header files in the readline module, to make
1709 it compile (albeit with some warnings) with the very recent readline
1710 4.2, without breaking for earlier versions.
1711
1712- Hopefully fixed a buffering problem in linuxaudiodev.
1713
1714- Attempted a fix to make the OpenSSL support in the socket module
1715 work again with pre-0.9.5 versions of OpenSSL.
1716
1717Tests
1718
1719- Added a test case for asynchat and asyncore.
1720
1721- Removed coupling between tests where one test failing could break
1722 another.
1723
1724Tools
1725
1726- Ping added an interactive help browser to pydoc, fixed some nits
1727 in the rest of the pydoc code, and added some features to his
1728 inspect module.
1729
1730- An updated python-mode.el version 4.1 which integrates Ken
1731 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1732 much nicer in XEmacs and Emacs. When stepping through your program
1733 with pdb, in either the shell window or the *Python* window, the
1734 source file and line will be tracked by an arrow. Very cool!
1735
1736- IDLE: syntax warnings in interactive mode are changed into errors.
1737
1738- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001739 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001740
1741- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001742
Barry Warsaw11e89c72001-04-11 20:37:57 +00001743
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001744What's New in Python 2.1 beta 2?
1745================================
1746
Guido van Rossum053ae352001-03-22 14:17:21 +00001747(Unlisted are many fixed bugs, more documentation, etc.)
1748
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001749Core language, builtins, and interpreter
1750
Guido van Rossum053ae352001-03-22 14:17:21 +00001751- The nested scopes work (enabled by "from __future__ import
1752 nested_scopes") is completed; in particular, the future now extends
1753 into code executed through exec, eval() and execfile(), and into the
1754 interactive interpreter.
1755
1756- When calling a base class method (e.g. BaseClass.__init__(self)),
1757 this is now allowed even if self is not strictly spoken a class
1758 instance (e.g. when using metaclasses or the Don Beaudry hook).
1759
1760- Slice objects are now comparable but not hashable; this prevents
1761 dict[:] from being accepted but meaningless.
1762
1763- Complex division is now calculated using less braindead algorithms.
1764 This doesn't change semantics except it's more likely to give useful
1765 results in extreme cases. Complex repr() now uses full precision
1766 like float repr().
1767
1768- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1769
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001770- It is illegal to assign to the name __debug__, which is set when the
1771 interpreter starts. It is effectively a compile-time constant.
1772
1773- A warning will be issued if a global statement for a variable
1774 follows a use or assignment of that variable.
1775
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001776Standard library
1777
Guido van Rossum053ae352001-03-22 14:17:21 +00001778- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1779 inspired by JUnit), is now part of the standard library. You now
1780 have a choice of two testing frameworks: unittest requires you to
1781 write testcases as separate code, doctest gathers them from
1782 docstrings. Both approaches have their advantages and
1783 disadvantages.
1784
1785- A new module Tix was added, which wraps the Tix extension library
1786 for Tk. With that module, it is not necessary to statically link
1787 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1788 require" command. See Demo/tix/.
1789
1790- tzparse.py is now obsolete.
1791
1792- In gzip.py, the seek() and tell() methods are removed -- they were
1793 non-functional anyway, and it's better if callers can test for their
1794 existence with hasattr().
1795
1796Python/C API
1797
1798- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1799 that's already in the dictionary during a PyDict_Next() iteration.
1800 This used to fail occasionally when a dictionary resize operation
1801 could be triggered that would rehash all the keys. All other
1802 modifications to the dictionary are still off-limits during a
1803 PyDict_Next() iteration!
1804
1805- New extended APIs related to passing compiler variables around.
1806
1807- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1808 implement isinstance() and issubclass().
1809
1810- Py_BuildValue() now has a "D" conversion to create a Python complex
1811 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001812
Fred Drake4e262a92001-03-22 18:26:47 +00001813- Extensions types which support weak references must now set the
1814 field allocated for the weak reference machinery to NULL themselves;
1815 this is done to avoid the cost of checking each object for having a
1816 weakly referencable type in PyObject_INIT(), since most types are
1817 not weakly referencable.
1818
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001819- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1820 free variables and cell variables to and from the frame's f_locals.
1821
1822- Variants of several functions defined in pythonrun.h have been added
1823 to support the nested_scopes future statement. The variants all end
1824 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1825 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1826 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001827 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001828
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001829Distutils
1830
1831- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1832 into the release tree.
1833
Tim Peters0e57abf2001-05-02 07:39:38 +00001834- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001835 (an uninstaller, more customization of the installer's display)
1836
1837- from Jack Jansen: added Mac-specific code to generate a dialog for
1838 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001839 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001840 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001841
1842- added 'platforms' and 'keywords' to the set of metadata that can be
1843 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001844
1845- applied patches from Jason Tishler to make the compiler class work with
1846 Cygwin.
1847
1848
Tim Peters2fe289a2001-03-01 22:19:38 +00001849What's New in Python 2.1 beta 1?
1850================================
Tim Petersd66595f2001-02-04 03:09:53 +00001851
1852Core language, builtins, and interpreter
1853
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001854- Following an outcry from the community about the amount of code
1855 broken by the nested scopes feature introduced in 2.1a2, we decided
1856 to make this feature optional, and to wait until Python 2.2 (or at
1857 least 6 months) to make it standard. The option can be enabled on a
1858 per-module basis by adding "from __future__ import nested_scopes" at
1859 the beginning of a module (before any other statements, but after
1860 comments and an optional docstring). See PEP 236 (Back to the
1861 __future__) for a description of the __future__ statement. PEP 227
1862 (Statically Nested Scopes) has been updated to reflect this change,
1863 and to clarify the semantics in a number of endcases.
1864
1865- The nested scopes code, when enabled, has been hardened, and most
1866 bugs and memory leaks in it have been fixed.
1867
1868- Compile-time warnings are now generated for a number of conditions
1869 that will break or change in meaning when nested scopes are enabled:
1870
1871 - Using "from...import *" or "exec" without in-clause in a function
1872 scope that also defines a lambda or nested function with one or
1873 more free (non-local) variables. The presence of the import* or
1874 bare exec makes it impossible for the compiler to determine the
1875 exact set of local variables in the outer scope, which makes it
1876 impossible to determine the bindings for free variables in the
1877 inner scope. To avoid the warning about import *, change it into
1878 an import of explicitly name object, or move the import* statement
1879 to the global scope; to avoid the warning about bare exec, use
1880 exec...in... (a good idea anyway -- there's a possibility that
1881 bare exec will be deprecated in the future).
1882
1883 - Use of a global variable in a nested scope with the same name as a
1884 local variable in a surrounding scope. This will change in
1885 meaning with nested scopes: the name in the inner scope will
1886 reference the variable in the outer scope rather than the global
1887 of the same name. To avoid the warning, either rename the outer
1888 variable, or use a global statement in the inner function.
1889
Neil Schemenauera35c6882001-02-27 04:45:05 +00001890- An optional object allocator has been included. This allocator is
1891 optimized for Python objects and should be faster and use less memory
1892 than the standard system allocator. It is not enabled by default
1893 because of possible thread safety problems. The allocator is only
1894 protected by the Python interpreter lock and it is possible that some
1895 extension modules require a thread safe allocator. The object
1896 allocator can be enabled by providing the "--with-pymalloc" option to
1897 configure.
1898
Tim Petersd66595f2001-02-04 03:09:53 +00001899Standard library
1900
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001901- pyexpat now detects the expat version if expat.h defines it. A
1902 number of additional handlers are provided, which are only available
1903 since expat 1.95. In addition, the methods SetParamEntityParsing and
1904 GetInputContext of Parser objects are available with 1.95.x
1905 only. Parser objects now provide the ordered_attributes and
1906 specified_attributes attributes. A new module expat.model was added,
1907 which offers a number of additional constants if 1.95.x is used.
1908
1909- xml.dom offers the new functions registerDOMImplementation and
1910 getDOMImplementation.
1911
1912- xml.dom.minidom offers a toprettyxml method. A number of DOM
1913 conformance issues have been resolved. In particular, Element now
1914 has an hasAttributes method, and the handling of namespaces was
1915 improved.
1916
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001917- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1918 getting information about live Python code, and pydoc.py, a module
1919 for interactively converting docstrings to HTML or text.
1920 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001921 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001922 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1923 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001924
Tim Peters1eff7962001-03-01 02:31:33 +00001925- New library module difflib.py, primarily packaging the SequenceMatcher
1926 class at the heart of the popular ndiff.py file-comparison tool.
1927
1928- doctest.py (a framework for verifying Python code examples in docstrings)
1929 is now part of the std library.
1930
Tim Petersd66595f2001-02-04 03:09:53 +00001931Windows changes
1932
Guido van Rossume3955a82001-03-02 14:05:59 +00001933- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1934 small GUI that lets you browse the module docstrings using your
1935 default web browser.
1936
Tim Peters1eff7962001-03-01 02:31:33 +00001937- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1938 Platforms) is implemented. See
1939
1940 http://python.sourceforge.net/peps/pep-0235.html
1941
1942 for full details, especially the "Current Lower-Left Semantics" section.
1943 The new Windows import rules are simpler than before:
1944
1945 A. If the PYTHONCASEOK environment variable exists, same as
1946 before: silently accept the first case-insensitive match of any
1947 kind; raise ImportError if none found.
1948
1949 B. Else search sys.path for the first case-sensitive match; raise
1950 ImportError if none found.
1951
1952 The same rules have been implented on other platforms with case-
1953 insensitive but case-preserving filesystems too (including Cygwin, and
1954 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001955
Tim Peters25a9ce32001-02-19 07:06:36 +00001956- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1957 what it's supposed to do (and does do under NT and 2000) via direct
1958 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001959 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001960 all Win9x systems before.
1961
Tim Peters1eff7962001-03-01 02:31:33 +00001962- Build: Subproject _test (effectively) renamed to _testcapi.
1963
Tim Peters2fe289a2001-03-01 22:19:38 +00001964New platforms
1965
1966- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1967 Thanks to Steven Majewski!
1968
1969- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1970 Tishler!
1971
Guido van Rossum9089b272001-03-02 06:49:50 +00001972- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1973 Schwertberger! See RISCOS/README for more information -- it seems
1974 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001975 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001976
Tim Peters25a9ce32001-02-19 07:06:36 +00001977
Tim Petersd7b5e882001-01-25 03:36:26 +00001978What's New in Python 2.1 alpha 2?
1979=================================
Tim Peters40ead762001-01-27 05:35:26 +00001980
Tim Petersd7b5e882001-01-25 03:36:26 +00001981Core language, builtins, and interpreter
1982
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001983- Scopes nest. If a name is used in a function or class, but is not
1984 local, the definition in the nearest enclosing function scope will
1985 be used. One consequence of this change is that lambda statements
1986 could reference variables in the namespaces where the lambda is
1987 defined. In some unusual cases, this change will break code.
1988
1989 In all previous version of Python, names were resolved in exactly
1990 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001991 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001992 function A is defined within a function B, the names bound in B are
1993 not visible in A. The new rules make names bound in B visible in A,
1994 unless A contains a name binding that hides the binding in B.
1995
1996 Section 4.1 of the reference manual describes the new scoping rules
1997 in detail. The test script in Lib/test/test_scope.py demonstrates
1998 some of the effects of the change.
1999
2000 The new rules will cause existing code to break if it defines nested
2001 functions where an outer function has local variables with the same
2002 name as globals or builtins used by the inner function. Example:
2003
2004 def munge(str):
2005 def helper(x):
2006 return str(x)
2007 if type(str) != type(''):
2008 str = helper(str)
2009 return str.strip()
2010
2011 Under the old rules, the name str in helper() is bound to the
2012 builtin function str(). Under the new rules, it will be bound to
2013 the argument named str and an error will occur when helper() is
2014 called.
2015
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002016- The compiler will report a SyntaxError if "from ... import *" occurs
2017 in a function or class scope. The language reference has documented
2018 that this case is illegal, but the compiler never checked for it.
2019 The recent introduction of nested scope makes the meaning of this
2020 form of name binding ambiguous. In a future release, the compiler
2021 may allow this form when there is no possibility of ambiguity.
2022
Tim Peters40ead762001-01-27 05:35:26 +00002023- repr(string) is easier to read, now using hex escapes instead of octal,
2024 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
2025
2026 >>> "\texample \r\n" + chr(0) + chr(255)
2027 '\texample \r\n\x00\xff' # in 2.1
2028 '\011example \015\012\000\377' # in 2.0
2029
Moshe Zadka6af0ce02001-01-29 06:41:00 +00002030- Functions are now compared and hashed by identity, not by value, since
2031 the func_code attribute is writable.
2032
Fred Drakefb9d7122001-02-01 20:00:40 +00002033- Weak references (PEP 205) have been added. This involves a few
2034 changes in the core, an extension module (_weakref), and a Python
2035 module (weakref). The weakref module is the public interface. It
2036 includes support for "explicit" weak references, proxy objects, and
2037 mappings with weakly held values.
2038
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002039- A 'continue' statement can now appear in a try block within the body
2040 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00002041 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00002042
Tim Petersd7b5e882001-01-25 03:36:26 +00002043Standard library
2044
Barry Warsaw30dbd142001-01-31 22:14:01 +00002045- mailbox.py now has a new class, PortableUnixMailbox which is
2046 identical to UnixMailbox but uses a more portable scheme for
2047 determining From_ separators. Also, the constructors for all the
2048 classes in this module have a new optional `factory' argument, which
2049 is a callable used when new message classes must be instantiated by
2050 the next() method.
2051
Tim Petersd7b5e882001-01-25 03:36:26 +00002052- random.py is now self-contained, and offers all the functionality of
2053 the now-deprecated whrandom.py. See the docs for details. random.py
2054 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00002055 and restoring the internal state of the generator; and jumpahead(n),
2056 for quickly forcing the internal state to be the same as if n calls to
2057 random() had been made. The latter is particularly useful for multi-
2058 threaded programs, creating one instance of the random.Random() class for
2059 each thread, then using .jumpahead() to force each instance to use a
2060 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00002061
Tim Peters0de88fc2001-02-01 04:59:18 +00002062- random.py's seed() function is new. For bit-for-bit compatibility with
2063 prior releases, use the whseed function instead. The new seed function
2064 addresses two problems: (1) The old function couldn't produce more than
2065 about 2**24 distinct internal states; the new one about 2**45 (the best
2066 that can be done in the Wichmann-Hill generator). (2) The old function
2067 sometimes produced identical internal states when passed distinct
2068 integers, and there was no simple way to predict when that would happen;
2069 the new one guarantees to produce distinct internal states for all
2070 arguments in [0, 27814431486576L).
2071
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00002072- The socket module now supports raw packets on Linux. The socket
2073 family is AF_PACKET.
2074
Tim Peters9ea17ac2001-02-02 05:57:15 +00002075- test_capi.py is a start at running tests of the Python C API. The tests
2076 are implemented by the new Modules/_testmodule.c.
2077
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002078- A new extension module, _symtable, provides provisional access to the
2079 internal symbol table used by the Python compiler. A higher-level
2080 interface will be added on top of _symtable in a future release.
2081
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002082- Removed the obsolete soundex module.
2083
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002084- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2085 the isSameNode method; NamedNodeMap the get method.
2086
2087- xml.sax.expatreader supports the lexical handler property; it
2088 generates comment, startCDATA, and endCDATA events.
2089
Tim Petersee826f82001-01-31 19:39:44 +00002090Windows changes
2091
2092- Build procedure: the zlib project is built in a different way that
2093 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002094 the zlib binary used. See PCbuild\readme.txt for details. Your old
2095 zlib-related directories can be deleted; you'll need to download fresh
2096 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002097
Tim Peters9ea17ac2001-02-02 05:57:15 +00002098- Build: New subproject _test for the benefit of test_capi.py (see above).
2099
Tim Petersb16c56f2001-02-02 21:24:51 +00002100- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2101 interface to some Python compiler internals).
2102
2103- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002104 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002105
Tim Petersa3a3a032000-11-30 05:22:44 +00002106What's New in Python 2.1 alpha 1?
2107=================================
2108
2109Core language, builtins, and interpreter
2110
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002111- There is a new Unicode companion to the PyObject_Str() API
2112 called PyObject_Unicode(). It behaves in the same way as the
2113 former, but assures that the returned value is an Unicode object
2114 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002115
Guido van Rossumf98eda02001-01-17 15:54:45 +00002116- The comparison operators support "rich comparison overloading" (PEP
2117 207). C extension types can provide a rich comparison function in
2118 the new tp_richcompare slot in the type object. The cmp() function
2119 and the C function PyObject_Compare() first try the new rich
2120 comparison operators before trying the old 3-way comparison. There
2121 is also a new C API PyObject_RichCompare() (which also falls back on
2122 the old 3-way comparison, but does not constrain the outcome of the
2123 rich comparison to a Boolean result).
2124
2125 The rich comparison function takes two objects (at least one of
2126 which is guaranteed to have the type that provided the function) and
2127 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2128 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2129 object, which may be NotImplemented (in which case the tp_compare
2130 slot function is used as a fallback, if defined).
2131
2132 Classes can overload individual comparison operators by defining one
2133 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002134 __ge__. There are no explicit "reflected argument" versions of
2135 these; instead, __lt__ and __gt__ are each other's reflection,
2136 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2137 reflection (similar at the C level). No other implications are
2138 made; in particular, Python does not assume that == is the Boolean
2139 inverse of !=, or that < is the Boolean inverse of >=. This makes
2140 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002141
2142 Classes or types that want to implement (in)equality tests but not
2143 the ordering operators (i.e. unordered types) should implement ==
2144 and !=, and raise an error for the ordering operators.
2145
Guido van Rossuma88479f2001-01-18 14:28:08 +00002146 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002147 Boolean; e.g. a matrix type might want to return a matrix of bits
2148 for A < B, giving elementwise comparisons. Such types should ensure
2149 that any interpretation of their value in a Boolean context raises
2150 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2151 at the C level) to always raise an exception.
2152
Guido van Rossuma88479f2001-01-18 14:28:08 +00002153- Complex numbers use rich comparisons to define == and != but raise
2154 an exception for <, <=, > and >=. Unfortunately, this also means
2155 that cmp() of two complex numbers raises an exception when the two
2156 numbers differ. Since it is not mathematically meaningful to compare
2157 complex numbers except for equality, I hope that this doesn't break
2158 too much code.
2159
Tim Peters3389f192001-02-18 08:48:49 +00002160- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002161 not defined by the language, other than that it's arbitrary but
2162 consistent (see the Reference Manual). An implementation detail changed
2163 in 2.1a1 such that None now compares less than any other object. Code
2164 relying on this new behavior (like code that relied on the previous
2165 behavior) does so at its own risk.
2166
Barry Warsaw573b5412001-01-15 20:43:18 +00002167- Functions and methods now support getting and setting arbitrarily
2168 named attributes (PEP 232). Functions have a new __dict__
2169 (a.k.a. func_dict) which hold the function attributes. Methods get
2170 and set attributes on their underlying im_func. It is a TypeError
2171 to set an attribute on a bound method.
2172
Guido van Rossum051e3352001-01-15 19:11:10 +00002173- The xrange() object implementation has been improved so that
2174 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2175 limitation that in this case len(xrange(sys.maxint)) can't be
2176 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2177 work fine as long as the index i doesn't actually reach 2**31.
2178 (Python uses regular ints for sequence and string indices; fixing
2179 that is much more work.)
2180
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002181- Two changes to from...import:
2182
Guido van Rossumba381232001-02-03 15:06:40 +00002183 1) "from M import X" now works even if (after loading module M)
2184 sys.modules['M'] is not a real module; it's basically a getattr()
2185 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002186
2187 2) "from M import *" now looks for M.__all__ to decide which names to
2188 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2189 filters out names starting with '_' as before. Whether or not
2190 __all__ exists, there's no restriction on the type of M.
2191
Guido van Rossumf61f1662001-01-10 20:13:55 +00002192- File objects have a new method, xreadlines(). This is the fastest
2193 way to iterate over all lines in a file:
2194
2195 for line in file.xreadlines():
2196 ...do something to line...
2197
2198 See the xreadlines module (mentioned below) for how to do this for
2199 other file-like objects.
2200
2201- Even if you don't use file.xreadlines(), you may expect a speedup on
2202 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002203 quite a bit in platform-specific ways: on systems (like Linux) that
2204 support flockfile(), getc_unlocked(), and funlockfile(), those are
2205 used by default. On systems (like Windows) without getc_unlocked(),
2206 a complicated (but still thread-safe) method using fgets() is used by
2207 default.
2208
Tim Petersd52269b2001-01-25 06:23:18 +00002209 You can force use of the fgets() method by #define'ing
2210 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002211 getc_unlocked()).
2212
Tim Petersd52269b2001-01-25 06:23:18 +00002213 You can force fgets() not to be used by #define'ing
2214 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002215 test_bufio.py fails -- and let us know if it does!).
2216
2217- In addition, the fileinput module, while still slower than the other
2218 methods on most platforms, has been sped up too, by using
2219 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002220
2221- Support for run-time warnings has been added, including a new
2222 command line option (-W) to specify the disposition of warnings.
2223 See the description of the warnings module below.
2224
2225- Extensive changes have been made to the coercion code. This mostly
2226 affects extension modules (which can now implement mixed-type
2227 numerical operators without having to use coercion), but
2228 occasionally, in boundary cases the coercion semantics have changed
2229 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002230 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002231 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002232 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002233
Guido van Rossumf98eda02001-01-17 15:54:45 +00002234- In connection with the coercion changes, a new built-in singleton
2235 object, NotImplemented is defined. This can be returned for
2236 operations that wish to indicate they are not implemented for a
2237 particular combination of arguments. From C, this is
2238 Py_NotImplemented.
2239
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002240- The interpreter accepts now bytecode files on the command line even
2241 if they do not have a .pyc or .pyo extension. On Linux, after executing
2242
Martin v. Löwise214baa2001-02-04 22:37:56 +00002243import imp,sys,string
2244magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2245reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2246open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002247
2248 any byte code file can be used as an executable (i.e. as an argument
2249 to execve(2)).
2250
Tim Peters9940b802000-12-01 07:59:35 +00002251- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002252 character. In 1.6 and earlier, they never produced a sign,
2253 and raised an error if the value of the long was too large
2254 to fit in a Python int. In 2.0, they produced a sign if and
2255 only if too large to fit in an int. This was inconsistent
2256 across platforms (because the size of an int varies across
2257 platforms), and inconsistent with hex() and oct(). Example:
2258
2259 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002260 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002261 'ffffffbe' # in 2.0 and before, on 32-bit machines
2262 >>> hex(-0x42L)
2263 '-0x42L' # in all versions of Python
2264
Tim Peters9940b802000-12-01 07:59:35 +00002265 The behavior of %d formats for negative Python longs remains
2266 the same as in 2.0 (although in 1.6 and before, they raised
2267 an error if the long didn't fit in a Python int).
2268
2269 %u formats don't make sense for Python longs, but are allowed
2270 and treated the same as %d in 2.1. In 2.0, a negative long
2271 formatted via %u produced a sign if and only if too large to
2272 fit in an int. In 1.6 and earlier, a negative long formatted
2273 via %u raised an error if it was too big to fit in an int.
2274
Guido van Rossum3661d392000-12-12 22:10:31 +00002275- Dictionary objects have an odd new method, popitem(). This removes
2276 an arbitrary item from the dictionary and returns it (in the form of
2277 a (key, value) pair). This can be useful for algorithms that use a
2278 dictionary as a bag of "to do" items and repeatedly need to pick one
2279 item. Such algorithms normally end up running in quadratic time;
2280 using popitem() they can usually be made to run in linear time.
2281
Tim Peters36cdad12000-12-29 02:06:45 +00002282Standard library
2283
Thomas Woutersfe385252001-01-19 23:16:56 +00002284- In the time module, the time argument to the functions strftime,
2285 localtime, gmtime, asctime and ctime is now optional, defaulting to
2286 the current time (in the local timezone).
2287
Guido van Rossumda91f222001-01-15 16:36:08 +00002288- The ftplib module now defaults to passive mode, which is deemed a
2289 more useful default given that clients are often inside firewalls
2290 these days. Note that this could break if ftplib is used to connect
2291 to a *server* that is inside a firewall, from outside; this is
2292 expected to be a very rare situation. To fix that, you can call
2293 ftp.set_pasv(0).
2294
Martin v. Löwis10a27872001-01-13 09:54:41 +00002295- The module site now treats .pth files not only for path configuration,
2296 but also supports extensions to the initialization code: Lines starting
2297 with import are executed.
2298
Guido van Rossumf61f1662001-01-10 20:13:55 +00002299- There's a new module, warnings, which implements a mechanism for
2300 issuing and filtering warnings. There are some new built-in
2301 exceptions that serve as warning categories, and a new command line
2302 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2303 turns warnings into errors). warnings.warn(message[, category])
2304 issues a warning message; this can also be called from C as
2305 PyErr_Warn(category, message).
2306
2307- A new module xreadlines was added. This exports a single factory
2308 function, xreadlines(). The intention is that this code is the
2309 absolutely fastest way to iterate over all lines in an open
2310 file(-like) object:
2311
2312 import xreadlines
2313 for line in xreadlines.xreadlines(file):
2314 ...do something to line...
2315
2316 This is equivalent to the previous the speed record holder using
2317 file.readlines(sizehint). Note that if file is a real file object
2318 (as opposed to a file-like object), this is equivalent:
2319
2320 for line in file.xreadlines():
2321 ...do something to line...
2322
Tim Peters36cdad12000-12-29 02:06:45 +00002323- The bisect module has new functions bisect_left, insort_left,
2324 bisect_right and insort_right. The old names bisect and insort
2325 are now aliases for bisect_right and insort_right. XXX_right
2326 and XXX_left methods differ in what happens when the new element
2327 compares equal to one or more elements already in the list: the
2328 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002329 right. Code that doesn't care where equal elements end up should
2330 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002331
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002332- The new curses.panel module wraps the panel library that forms part
2333 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2334
Guido van Rossumf61f1662001-01-10 20:13:55 +00002335- The SocketServer module now sets the allow_reuse_address flag by
2336 default in the TCPServer class.
2337
2338- A new function, sys._getframe(), returns the stack frame pointer of
2339 the caller. This is intended only as a building block for
2340 higher-level mechanisms such as string interpolation.
2341
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002342- The pyexpat module supports a number of new handlers, which are
2343 available only in expat 1.2. If invocation of a callback fails, it
2344 will report an additional frame in the traceback. Parser objects
2345 participate now in garbage collection. If expat reports an unknown
2346 encoding, pyexpat will try to use a Python codec; that works only
2347 for single-byte charsets. The parser type objects is exposed as
2348 XMLParserObject.
2349
2350- xml.dom now offers standard definitions for symbolic node type and
2351 exception code constants, and a hierarchy of DOM exceptions. minidom
2352 was adjusted to use them.
2353
2354- The conformance of xml.dom.minidom to the DOM specification was
2355 improved. It detects a number of additional error cases; the
2356 previous/next relationship works even when the tree is modified;
2357 Node supports the normalize() method; NamedNodeMap, DocumentType and
2358 DOMImplementation classes were added; Element supports the
2359 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2360 method.
2361
Guido van Rossumf61f1662001-01-10 20:13:55 +00002362Build issues
2363
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002364- For Unix (and Unix-compatible) builds, configuration and building of
2365 extension modules is now greatly automated. Rather than having to
2366 edit the Modules/Setup file to indicate which modules should be
2367 built and where their include files and libraries are, a
2368 distutils-based setup.py script now takes care of building most
2369 extension modules. All extension modules built this way are built
2370 as shared libraries. Only a few modules that must be linked
2371 statically are still listed in the Setup file; you won't need to
2372 edit their configuration.
2373
2374- Python should now build out of the box on Cygwin. If it doesn't,
2375 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002376
2377- Python now always uses its own (renamed) implementation of getopt()
2378 -- there's too much variation among C library getopt()
2379 implementations.
2380
2381- C++ compilers are better supported; the CXX macro is always set to a
2382 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002383
Tim Petersd92dfe02000-12-12 01:18:41 +00002384Windows changes
2385
2386- select module: By default under Windows, a select() call
2387 can specify no more than 64 sockets. Python now boosts
2388 this Microsoft default to 512. If you need even more than
2389 that, see the MS docs (you'll need to #define FD_SETSIZE
2390 and recompile Python from source).
2391
Guido van Rossumf61f1662001-01-10 20:13:55 +00002392- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2393 subdirectory is no more!
2394
Tim Petersa3a3a032000-11-30 05:22:44 +00002395
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002396What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002397=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002398
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002399Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002400changes are in the file HISTORY. If you are making the jump directly
2401from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2402HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002403
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002404Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2405the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2406http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002407
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002408--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002409
2410======================================================================
2411
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002412What's new in 2.0 (since release candidate 1)?
2413==============================================
2414
2415Standard library
2416
2417- The copy_reg module was modified to clarify its intended use: to
2418 register pickle support for extension types, not for classes.
2419 pickle() will raise a TypeError if it is passed a class.
2420
2421- Fixed a bug in gettext's "normalize and expand" code that prevented
2422 it from finding an existing .mo file.
2423
2424- Restored support for HTTP/0.9 servers in httplib.
2425
Tim Peters989b7b92000-10-16 20:24:53 +00002426- The math module was changed to stop raising OverflowError in case of
2427 underflow, and return 0 instead in underflow cases. Whether Python
2428 used to raise OverflowError in case of underflow was platform-
2429 dependent (it did when the platform math library set errno to ERANGE
2430 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002431
2432- Fixed a bug in StringIO that occurred when the file position was not
2433 at the end of the file and write() was called with enough data to
2434 extend past the end of the file.
2435
2436- Fixed a bug that caused Tkinter error messages to get lost on
2437 Windows. The bug was fixed by replacing direct use of
2438 interp->result with Tcl_GetStringResult(interp).
2439
2440- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2441 redirect response.
2442
2443- Several changes were made to distutils: Some debugging code was
2444 removed from util. Fixed the installer used when an external zip
2445 program (like WinZip) is not found; the source code for this
2446 installer is in Misc/distutils. check_lib() was modified to behave
2447 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2448 test for whether installed modules are on sys.path was changed to
2449 use both normcase() and normpath().
2450
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002451- Several minor bugs were fixed in the xml package (the minidom,
2452 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002453
2454- The regression test driver (regrtest.py) behavior when invoked with
2455 -l changed: It now reports a count of objects that are recognized as
2456 garbage but not freed by the garbage collector.
2457
Tim Peters989b7b92000-10-16 20:24:53 +00002458- The regression test for the math module was changed to test
2459 exceptional behavior when the test is run in verbose mode. Python
2460 cannot yet guarantee consistent exception behavior across platforms,
2461 so the exception part of test_math is run only in verbose mode, and
2462 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002463
2464Internals
2465
2466- PyOS_CheckStack() has been disabled on Win64, where it caused
2467 test_sre to fail.
2468
2469Build issues
2470
2471- Changed compiler flags, so that gcc is always invoked with -Wall and
2472 -Wstrict-prototypes. Users compiling Python with GCC should see
2473 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002474 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002475 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002476
Tim Petersa3a3a032000-11-30 05:22:44 +00002477- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002478
2479Tools and other miscellany
2480
2481- The compiler in Tools/compiler was updated to support the new
2482 language features introduced in 2.0: extended print statement, list
2483 comprehensions, and augmented assignments. The new compiler should
2484 also be backwards compatible with Python 1.5.2; the compiler will
2485 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002486 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002487
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002488What's new in 2.0 release candidate 1 (since beta 2)?
2489=====================================================
2490
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002491What is release candidate 1?
2492
2493We believe that release candidate 1 will fix all known bugs that we
2494intend to fix for the 2.0 final release. This release should be a bit
2495more stable than the previous betas. We would like to see even more
2496widespread testing before the final release, so we are producing this
2497release candidate. The final release will be exactly the same unless
2498any show-stopping (or brown bag) bugs are found by testers of the
2499release candidate.
2500
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002501All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002502to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002503
2504Core language, builtins, and interpreter
2505
2506- A bug that caused crashes when __coerce__ was used with augmented
2507 assignment, e.g. +=, was fixed.
2508
2509- Raise ZeroDivisionError when raising zero to a negative number,
2510 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2511 power operator and the result of math.pow(0.0, -2.0) will vary by
2512 platform. On Linux, it raises a ValueError.
2513
2514- A bug in Unicode string interpolation was fixed that occasionally
2515 caused errors with formats including "%%". For example, the
2516 following expression "%% %s" % u"abc" no longer raises a TypeError.
2517
2518- Compilation of deeply nested expressions raises MemoryError instead
2519 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2520
2521- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2522 rendering them useless. They are now written in binary mode again.
2523
2524Standard library
2525
2526- Keyword arguments are now accepted for most pattern and match object
2527 methods in SRE, the standard regular expression engine.
2528
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002529- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002530 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002531
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002532- Several bugs in the Unicode handling and error handling in _tkinter
2533 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002534
2535- Fix memory management errors in Merge() and Tkapp_Call() routines.
2536
2537- Several changes were made to cStringIO to make it compatible with
2538 the file-like object interface and with StringIO. If operations are
2539 performed on a closed object, an exception is raised. The truncate
2540 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002541 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002542
2543- There were many changes made to the linuxaudiodev module and its
2544 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002545 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002546
2547 Note that this module is named poorly, because it should work
2548 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002549 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002550
2551 The module now raises exceptions when errors occur instead of
2552 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2553 audio) and defines a getptr() method that calls the
2554 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2555
2556- The library_version attribute, introduced in an earlier beta, was
2557 removed because it can not be supported with early versions of the C
2558 readline library, which provides no way to determine the version at
2559 compile-time.
2560
2561- The binascii module is now enabled on Win64.
2562
Tim Peters46446d62000-10-09 21:19:31 +00002563- tokenize.py no longer suffers "recursion depth" errors when parsing
2564 programs with very long string literals.
2565
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002566Internals
2567
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002568- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002569 which is called when the interpreter starts up to determine where
2570 the standard library is installed. These vulnerabilities affect all
2571 previous versions of Python and can be exploited by setting very
2572 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2573 setuid Python script, although use of the wrapper in
2574 Misc/setuid-prog.c will eliminate the vulnerability.
2575
2576- Fixed garbage collection bugs in instance creation that were
2577 triggered when errors occurred during initialization. The solution,
2578 applied in cPickle and in PyInstance_New(), is to call
2579 PyObject_GC_Init() after the initialization of the object's
2580 container attributes is complete.
2581
2582- pyexpat adds definitions of PyModule_AddStringConstant and
2583 PyModule_AddObject if the Python version is less than 2.0, which
2584 provides compatibility with PyXML on Python 1.5.2.
2585
2586- If the platform has a bogus definition for LONG_BIT (the number of
2587 bits in a long), an error will be reported at compile time.
2588
2589- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2590 collection crashes and possibly other, unreported crashes.
2591
2592- Fixed a memory leak in _PyUnicode_Fini().
2593
2594Build issues
2595
2596- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002597 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002598 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002599
2600- The mmap.PAGESIZE constant is now initialized using sysconf when
2601 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2602
2603- The md5 file should now compile on all platforms.
2604
2605- The select module now compiles on platforms that do not define
2606 POLLRDNORM and related constants.
2607
2608- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002609 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002610
Jeremy Hylton10921202000-10-09 18:34:12 +00002611- BeOS: A number of changes were made to the build and installation
2612 process. ar-fake now operates on a directory of object files.
2613 dl_export.h is gone, and its macros now appear on the mwcc command
2614 line during build on PPC BeOS.
2615
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002616- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002617 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002618
2619- Cygwin: Support for shared libraries, Tkinter, and sockets.
2620
2621- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2622
2623Tools and other miscellany
2624
2625- Removed debugging prints from main used with freeze.
2626
Tim Peters46446d62000-10-09 21:19:31 +00002627- IDLE auto-indent no longer crashes when it encounters Unicode
2628 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002629
2630What's new in 2.0 beta 2 (since beta 1)?
2631========================================
2632
2633Core language, builtins, and interpreter
2634
Tim Peters482c0212000-09-26 06:33:09 +00002635- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002636 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002637
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002638- Add -h and -V command line options to print the usage message and
2639 Python version number and exit immediately.
2640
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002641- eval() and exec accept Unicode objects as code parameters.
2642
2643- getattr() and setattr() now also accept Unicode objects for the
2644 attribute name, which are converted to strings using the default
2645 encoding before lookup.
2646
2647- Multiplication on string and Unicode now does proper bounds
2648 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2649 string is too long."
2650
2651- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002652 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002653
Jeremy Hylton1b618592000-09-26 05:32:36 +00002654
2655Standard library and extensions
2656
Guido van Rossum5b08f132001-04-16 02:05:23 +00002657- socket module: the OpenSSL code now adds support for RAND_status()
2658 and EGD (Entropy Gathering Device).
2659
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002660- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002661 argument checking; it still takes no arguments.
2662
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002663- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002664
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002665- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002666
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002667- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002668
2669- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002670 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671
2672- copy: Copy Unicode objects atomically.
2673
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002674- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002675
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002676- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002677
Fred Drake67233bc2000-09-26 16:40:27 +00002678- dbm: Add get() and setdefault() methods to dbm object. Add constant
2679 `library' to module that names the library used. Added doc strings
2680 and method names to error messages. Uses configure to determine
2681 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2682 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002683
2684- distutils: Update to version 0.9.3.
2685
2686- dl: Add several dl.RTLD_ constants.
2687
2688- fpectl: Now supported on FreeBSD.
2689
2690- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2691 found by the collector will be saved in gc.garbage. This is useful
2692 for debugging a program that creates reference cycles.
2693
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002694- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002695 of HTTP class. Do not close socket on zero-length response. Do not
2696 crash when server sends invalid content-length header.
2697
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002698- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002699
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002700- marshal: When reading a short, sign-extend on platforms where shorts
2701 are bigger than 16 bits. When reading a long, repair the unportable
2702 sign extension that was being done for 64-bit machines. (It assumed
2703 that signed right shift sign-extends.)
2704
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002705- operator: Add contains(), invert(), __invert__() as aliases for
2706 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002707
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002708- os: Add support for popen2() and popen3() on all platforms where
2709 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002710
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002711- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002712 clicking on a file in Explorer (or passing the file name to the
2713 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002714
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002715- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002716 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002717
2718- pickle: Now raises ValueError when an invalid pickle that contains
2719 a non-string repr where a string repr was expected. This behavior
2720 matches cPickle.
2721
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002722- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002723
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002724- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002725
2726- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002727 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002728 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002729
2730- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002731 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002732
2733- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002734 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002735 few cycles during startup since the first call to
2736 setdefaultencoding() will initialize the codec registry and the
2737 encodings package.
2738
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002739- socket: Support for size hint in readlines() method of object returned
2740 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002741
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002742- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002743 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002744 is followed by whitespace.
2745
Tim Petersa3a3a032000-11-30 05:22:44 +00002746- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002747
2748- struct: Check ranges for bytes and shorts.
2749
2750- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002751 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752
2753- Tkinter: Image objects are now guaranteed to have unique ids. Set
2754 event.delta to zero if Tk version doesn't support mousewheel.
2755 Removed some debugging prints.
2756
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002757- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002758
Fred Drake67233bc2000-09-26 16:40:27 +00002759- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002760 which works around a bug in Norton AntiVirus 2000 that leads directly
2761 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002762
2763- xml: New version detection code allows PyXML to override standard
2764 XML package if PyXML version is greater than 0.6.1.
2765
Fred Drake64bb3802000-09-26 16:21:35 +00002766- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2767 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2768 tree only for nodes which are sufficiently interesting to a specific
2769 application. Does not provide the HTML-specific extensions. Still
2770 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002771
Fred Drake64bb3802000-09-26 16:21:35 +00002772- xml.sax: SAX 2 support for Python, including all the handler
2773 interfaces needed to process XML 1.0 compliant XML. Some
2774 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002775
Fred Drake64bb3802000-09-26 16:21:35 +00002776- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2777 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002778
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002779
Jeremy Hylton1b618592000-09-26 05:32:36 +00002780C API
2781
2782- Add three new convenience functions for module initialization --
2783 PyModule_AddObject(), PyModule_AddIntConstant(), and
2784 PyModule_AddStringConstant().
2785
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002786- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002787 removed and add #error to Python.h if NULL isn't defined after
2788 #include of stdio.h.
2789
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002790- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002791 backwards compatibility (at the source level) with old extensions.
2792
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002793- A wrapper API was added for signal() and sigaction(). Instead of
2794 either function, always use PyOS_getsig() to get a signal handler
2795 and PyOS_setsig() to set one. A new convenience typedef
2796 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002797
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002798- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002799 internal data buffer and size of a string object -- or the default
2800 encoded version of a Unicode object.
2801
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002802- PyString_Size() and PyString_AsString() accept Unicode objects.
2803
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002804- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002805 exists). INT_MAX and LONG_MAX will always be defined, even if
2806 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002807
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002808- PyFloat_FromString takes a second argument, pend, that was
2809 effectively useless. It is now officially useless but preserved for
2810 backwards compatibility. If the pend argument is not NULL, *pend is
2811 set to NULL.
2812
2813- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2814 for the attribute name. See note on getattr() above.
2815
2816- A few bug fixes to argument processing for Unicode.
2817 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2818 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2819 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002820 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002821
2822- Py_BuildValue accepts B format (for bgen-generated code).
2823
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002824
Jeremy Hylton1b618592000-09-26 05:32:36 +00002825Internals
2826
2827- On Unix, fix code for finding Python installation directory so that
2828 it works when argv[0] is a relative path.
2829
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002830- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002831 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002832 rather than by generating a copy of the object.
2833
Tim Peters482c0212000-09-26 06:33:09 +00002834- Several of the internal Unicode tables are much smaller now, and
2835 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002836
Jeremy Hylton97693b02000-09-26 17:42:51 +00002837- In the garbage collector: Fixed bug in collection of tuples. Fixed
2838 bug that caused some instances to be removed from the container set
2839 while they were still live. Fixed parsing in gc.set_debug() for
2840 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002841
2842- Fixed refcount problem in instance deallocation that only occurred
2843 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2844
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002845- On Windows, getpythonregpath is now protected against null data in
2846 registry key.
2847
2848- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002849 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002850
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002851
Jeremy Hylton1b618592000-09-26 05:32:36 +00002852Build and platform-specific issues
2853
2854- Better support of GNU Pth via --with-pth configure option.
2855
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002856- Python/C API now properly exposed to dynamically-loaded extension
2857 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002858
2859- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2860 Don't define MS_SYNC to be zero when it is undefined. Added missing
2861 prototypes in posixmodule.c.
2862
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002863- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002864 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002865
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002866- Fix largefile support on older NetBSD systems and OpenBSD by adding
2867 define for TELL64.
2868
2869
2870Tools and other miscellany
2871
2872- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2873
2874- freeze: The modulefinder now works with 2.0 opcodes.
2875
Tim Petersa3a3a032000-11-30 05:22:44 +00002876- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002877 Move hackery of sys.argv until after the Tk instance has been
2878 created, which allows the application-specific Tkinter
2879 initialization to be executed if present; also pass an explicit
2880 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002881
Jeremy Hylton1b618592000-09-26 05:32:36 +00002882
2883What's new in 2.0 beta 1?
2884=========================
2885
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002886Source Incompatibilities
2887------------------------
2888
2889None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2890such as single-argument append(), connect() and bind(), and changes to
2891str(long) and repr(float).
2892
2893
2894Binary Incompatibilities
2895------------------------
2896
2897- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2898with Python 2.0; these extensions will have to be rebuilt for Python
28992.0.
2900
2901- On Windows, attempting to import a third party extension built for
2902Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2903can do about this. Check your PYTHONPATH environment variable!
2904
2905- Python bytecode files (*.pyc and *.pyo) are not compatible between
2906releases.
2907
2908
2909Overview of Changes Since 1.6
2910-----------------------------
2911
2912There are many new modules (including brand new XML support through
2913the xml package, and i18n support through the gettext module); a list
2914of all new modules is included below. Lots of bugs have been fixed.
2915
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002916The process for making major new changes to the language has changed
2917since Python 1.6. Enhancements must now be documented by a Python
2918Enhancement Proposal (PEP) before they can be accepted.
2919
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002920There are several important syntax enhancements, described in more
2921detail below:
2922
2923 - Augmented assignment, e.g. x += 1
2924
2925 - List comprehensions, e.g. [x**2 for x in range(10)]
2926
2927 - Extended import statement, e.g. import Module as Name
2928
2929 - Extended print statement, e.g. print >> file, "Hello"
2930
2931Other important changes:
2932
2933 - Optional collection of cyclical garbage
2934
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002935Python Enhancement Proposal (PEP)
2936---------------------------------
2937
2938PEP stands for Python Enhancement Proposal. A PEP is a design
2939document providing information to the Python community, or describing
2940a new feature for Python. The PEP should provide a concise technical
2941specification of the feature and a rationale for the feature.
2942
2943We intend PEPs to be the primary mechanisms for proposing new
2944features, for collecting community input on an issue, and for
2945documenting the design decisions that have gone into Python. The PEP
2946author is responsible for building consensus within the community and
2947documenting dissenting opinions.
2948
2949The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002950
2951Augmented Assignment
2952--------------------
2953
2954This must have been the most-requested feature of the past years!
2955Eleven new assignment operators were added:
2956
Guido van Rossume905e952000-09-05 12:42:46 +00002957 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002958
2959For example,
2960
2961 A += B
2962
2963is similar to
2964
2965 A = A + B
2966
2967except that A is evaluated only once (relevant when A is something
2968like dict[index].attr).
2969
2970However, if A is a mutable object, A may be modified in place. Thus,
2971if A is a number or a string, A += B has the same effect as A = A+B
2972(except A is only evaluated once); but if a is a list, A += B has the
2973same effect as A.extend(B)!
2974
2975Classes and built-in object types can override the new operators in
2976order to implement the in-place behavior; the not-in-place behavior is
2977used automatically as a fallback when an object doesn't implement the
2978in-place behavior. For classes, the method name is derived from the
2979method name for the corresponding not-in-place operator by inserting
2980an 'i' in front of the name, e.g. __iadd__ implements in-place
2981__add__.
2982
2983Augmented assignment was implemented by Thomas Wouters.
2984
2985
2986List Comprehensions
2987-------------------
2988
2989This is a flexible new notation for lists whose elements are computed
2990from another list (or lists). The simplest form is:
2991
2992 [<expression> for <variable> in <sequence>]
2993
Guido van Rossum56db0952000-09-06 23:34:25 +00002994For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002995This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002996
2997You can also add a condition:
2998
2999 [<expression> for <variable> in <sequence> if <condition>]
3000
3001For example, [w for w in words if w == w.lower()] would yield the list
3002of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003003than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003004
3005You can also have nested for loops and more than one 'if' clause. For
3006example, here's a function that flattens a sequence of sequences::
3007
3008 def flatten(seq):
3009 return [x for subseq in seq for x in subseq]
3010
3011 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
3012
3013This prints
3014
3015 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
3016
3017List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003018Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003019
3020
3021Extended Import Statement
3022-------------------------
3023
3024Many people have asked for a way to import a module under a different
3025name. This can be accomplished like this:
3026
3027 import foo
3028 bar = foo
3029 del foo
3030
3031but this common idiom gets old quickly. A simple extension of the
3032import statement now allows this to be written as follows:
3033
3034 import foo as bar
3035
3036There's also a variant for 'from ... import':
3037
3038 from foo import bar as spam
3039
3040This also works with packages; e.g. you can write this:
3041
3042 import test.regrtest as regrtest
3043
3044Note that 'as' is not a new keyword -- it is recognized only in this
3045context (this is only possible because the syntax for the import
3046statement doesn't involve expressions).
3047
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003048Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003049
3050
3051Extended Print Statement
3052------------------------
3053
3054Easily the most controversial new feature, this extension to the print
3055statement adds an option to make the output go to a different file
3056than the default sys.stdout.
3057
3058For example, to write an error message to sys.stderr, you can now
3059write:
3060
3061 print >> sys.stderr, "Error: bad dog!"
3062
3063As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00003064evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003065
3066 print >> None, "Hello world"
3067
3068is equivalent to
3069
3070 print "Hello world"
3071
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003072Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003073
3074
3075Optional Collection of Cyclical Garbage
3076---------------------------------------
3077
3078Python is now equipped with a garbage collector that can hunt down
3079cyclical references between Python objects. It's no replacement for
3080reference counting; in fact, it depends on the reference counts being
3081correct, and decides that a set of objects belong to a cycle if all
3082their reference counts can be accounted for from their references to
3083each other. This devious scheme was first proposed by Eric Tiedemann,
3084and brought to implementation by Neil Schemenauer.
3085
3086There's a module "gc" that lets you control some parameters of the
3087garbage collection. There's also an option to the configure script
3088that lets you enable or disable the garbage collection. In 2.0b1,
3089it's on by default, so that we (hopefully) can collect decent user
3090experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003091performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003092off by default in the final 2.0 release.
3093
3094
3095Smaller Changes
3096---------------
3097
3098A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3099map(None, seq1, seq2, ...) when the sequences have the same length;
3100i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3101the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003102zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003103
3104sys.version_info is a tuple (major, minor, micro, level, serial).
3105
3106Dictionaries have an odd new method, setdefault(key, default).
3107dict.setdefault(key, default) returns dict[key] if it exists; if not,
3108it sets dict[key] to default and returns that value. Thus:
3109
3110 dict.setdefault(key, []).append(item)
3111
3112does the same work as this common idiom:
3113
3114 if not dict.has_key(key):
3115 dict[key] = []
3116 dict[key].append(item)
3117
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003118There are two new variants of SyntaxError that are raised for
3119indentation-related errors: IndentationError and TabError.
3120
3121Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3122escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003123
3124The limits on the size of expressions and file in Python source code
3125have been raised from 2**16 to 2**32. Previous versions of Python
3126were limited because the maximum argument size the Python VM accepted
3127was 2**16. This limited the size of object constructor expressions,
3128e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3129limit was raised thanks to a patch by Charles Waldman that effectively
3130fixes the problem. It is now much more likely that you will be
3131limited by available memory than by an arbitrary limit in Python.
3132
3133The interpreter's maximum recursion depth can be modified by Python
3134programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3135limit is the maximum number of recursive calls that can be made by
3136Python code. The limit exists to prevent infinite recursion from
3137overflowing the C stack and causing a core dump. The default value is
31381000. The maximum safe value for a particular platform can be found
3139by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003140
3141New Modules and Packages
3142------------------------
3143
3144atexit - for registering functions to be called when Python exits.
3145
3146imputil - Greg Stein's alternative API for writing custom import
3147hooks.
3148
3149pyexpat - an interface to the Expat XML parser, contributed by Paul
3150Prescod.
3151
3152xml - a new package with XML support code organized (so far) in three
3153subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3154would fill a volume. There's a special feature whereby a
3155user-installed package named _xmlplus overrides the standard
3156xmlpackage; this is intended to give the XML SIG a hook to distribute
3157backwards-compatible updates to the standard xml package.
3158
3159webbrowser - a platform-independent API to launch a web browser.
3160
3161
Guido van Rossume905e952000-09-05 12:42:46 +00003162Changed Modules
3163---------------
3164
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003165array -- new methods for array objects: count, extend, index, pop, and
3166remove
3167
3168binascii -- new functions b2a_hex and a2b_hex that convert between
3169binary data and its hex representation
3170
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003171calendar -- Many new functions that support features including control
3172over which day of the week is the first day, returning strings instead
3173of printing them. Also new symbolic constants for days of week,
3174e.g. MONDAY, ..., SUNDAY.
3175
3176cgi -- FieldStorage objects have a getvalue method that works like a
3177dictionary's get method and returns the value attribute of the object.
3178
3179ConfigParser -- The parser object has new methods has_option,
3180remove_section, remove_option, set, and write. They allow the module
3181to be used for writing config files as well as reading them.
3182
3183ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003184optionally support the RFC 959 REST command.
3185
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003186gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003187
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003188httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3189the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003190
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003191locale -- implement getdefaultlocale for Win32 and Macintosh
3192
3193marshal -- no longer dumps core when marshaling deeply nested or
3194recursive data structures
3195
3196os -- new functions isatty, seteuid, setegid, setreuid, setregid
3197
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003198os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3199support under Unix.
3200
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003201os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003202
3203os.path -- fix semantics of os.path.commonprefix
3204
3205smtplib -- support for sending very long messages
3206
3207socket -- new function getfqdn()
3208
3209readline -- new functions to read, write and truncate history files.
3210The readline section of the library reference manual contains an
3211example.
3212
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003213select -- add interface to poll system call
3214
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003215shutil -- new copyfileobj function
3216
3217SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3218HTTP server.
3219
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003220Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003221
3222urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003223e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003224
3225whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003226
3227
3228Obsolete Modules
3229----------------
3230
3231None. However note that 1.6 made a whole slew of modules obsolete:
3232stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3233poly, zmod, strop, util, whatsound.
3234
3235
3236Changed, New, Obsolete Tools
3237----------------------------
3238
Tim Peters8b092332000-09-05 20:15:25 +00003239None.
Guido van Rossume905e952000-09-05 12:42:46 +00003240
3241
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003242C-level Changes
3243---------------
3244
3245Several cleanup jobs were carried out throughout the source code.
3246
3247All C code was converted to ANSI C; we got rid of all uses of the
3248Py_PROTO() macro, which makes the header files a lot more readable.
3249
3250Most of the portability hacks were moved to a new header file,
3251pyport.h; several other new header files were added and some old
3252header files were removed, in an attempt to create a more rational set
3253of header files. (Few of these ever need to be included explicitly;
3254they are all included by Python.h.)
3255
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003256Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003257and Win64, especially for the new Intel Itanium processor. Mick also
3258added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003259
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003260The C APIs to return an object's size have been update to consistently
3261use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3262previous versions, the abstract interfaces used PyXXX_Length and the
3263concrete interfaces used PyXXX_Size. The old names,
3264e.g. PyObject_Length, are still available for backwards compatibility
3265at the API level, but are deprecated.
3266
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003267The PyOS_CheckStack function has been implemented on Windows by
3268Fredrik Lundh. It prevents Python from failing with a stack overflow
3269on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003270
3271The GC changes resulted in creation of two new slots on object,
3272tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003273the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003274
3275The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003276C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003277
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003278PyErr_Format has been updated to automatically calculate the size of
3279the buffer needed to hold the formatted result string. This change
3280prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003281
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003282New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003283
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003284PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3285that are the same as their non-Ex counterparts except they take an
3286extra flag argument that tells them to close the file when done.
3287
3288XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003289
Tim Peters8b092332000-09-05 20:15:25 +00003290
3291Windows Changes
3292---------------
3293
3294New popen2/popen3/peopen4 in os module (see Changed Modules above).
3295
3296os.popen is much more usable on Windows 95 and 98. See Microsoft
3297Knowledge Base article Q150956. The Win9x workaround described there
3298is implemented by the new w9xpopen.exe helper in the root of your
3299Python installation. Note that Python uses this internally; it is not
3300a standalone program.
3301
3302Administrator privileges are no longer required to install Python
3303on Windows NT or Windows 2000. If you have administrator privileges,
3304Python's registry info will be written under HKEY_LOCAL_MACHINE.
3305Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003306under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003307uses of Python, but will prevent some advanced uses from working
3308(for example, running a Python script as an NT service, or possibly
3309from CGI).
3310
3311[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3312installer; instead, it installs the needed Tcl/Tk files directly in the
3313Python directory. If you already have a Tcl/Tk installation, this
3314wastes some disk space (about 4 Megs) but avoids problems with
3315conflicting Tcl/Tk installations, and makes it much easier for Python
3316to ensure that Tcl/Tk can find all its files.
3317
3318[This was new in 1.6] The Windows installer now installs by default in
3319\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3320
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003321
3322Updates to the changes between 1.5.2 and 1.6
3323--------------------------------------------
3324
3325The 1.6 NEWS file can't be changed after the release is done, so here
3326is some late-breaking news:
3327
3328New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3329and changes to getlocale() and setlocale().
3330
3331The new module is now enabled per default.
3332
3333It is not true that the encodings codecs cannot be used for normal
3334strings: the string.encode() (which is also present on 8-bit strings
3335!) allows using them for 8-bit strings too, e.g. to convert files from
3336cp1252 (Windows) to latin-1 or vice-versa.
3337
3338Japanese codecs are available from Tamito KAJIYAMA:
3339http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3340
3341
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003342======================================================================